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+FFMPEG-FILTERS(1)					     FFMPEG-FILTERS(1)
+
+NAME
+       ffmpeg-filters - FFmpeg filters
+
+DESCRIPTION
+       This document describes filters, sources, and sinks provided by the
+       libavfilter library.
+
+FILTERING INTRODUCTION
+       Filtering in FFmpeg is enabled through the libavfilter library.
+
+       In libavfilter, a filter can have multiple inputs and multiple outputs.
+       To illustrate the sorts of things that are possible, we consider the
+       following filtergraph.
+
+			       [main]
+	       input --> split ---------------------> overlay --> output
+			   |				 ^
+			   |[tmp]		   [flip]|
+			   +-----> crop --> vflip -------+
+
+       This filtergraph splits the input stream in two streams, then sends one
+       stream through the crop filter and the vflip filter, before merging it
+       back with the other stream by overlaying it on top. You can use the
+       following command to achieve this:
+
+	       ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
+
+       The result will be that the top half of the video is mirrored onto the
+       bottom half of the output video.
+
+       Filters in the same linear chain are separated by commas, and distinct
+       linear chains of filters are separated by semicolons. In our example,
+       crop,vflip are in one linear chain, split and overlay are separately in
+       another. The points where the linear chains join are labelled by names
+       enclosed in square brackets. In the example, the split filter generates
+       two outputs that are associated to the labels [main] and [tmp].
+
+       The stream sent to the second output of split, labelled as [tmp], is
+       processed through the crop filter, which crops away the lower half part
+       of the video, and then vertically flipped. The overlay filter takes in
+       input the first unchanged output of the split filter (which was
+       labelled as [main]), and overlay on its lower half the output generated
+       by the crop,vflip filterchain.
+
+       Some filters take in input a list of parameters: they are specified
+       after the filter name and an equal sign, and are separated from each
+       other by a colon.
+
+       There exist so-called source filters that do not have an audio/video
+       input, and sink filters that will not have audio/video output.
+
+GRAPH
+       The graph2dot program included in the FFmpeg tools directory can be
+       used to parse a filtergraph description and issue a corresponding
+       textual representation in the dot language.
+
+       Invoke the command:
+
+	       graph2dot -h
+
+       to see how to use graph2dot.
+
+       You can then pass the dot description to the dot program (from the
+       graphviz suite of programs) and obtain a graphical representation of
+       the filtergraph.
+
+       For example the sequence of commands:
+
+	       echo <GRAPH_DESCRIPTION> | \
+	       tools/graph2dot -o graph.tmp && \
+	       dot -Tpng graph.tmp -o graph.png && \
+	       display graph.png
+
+       can be used to create and display an image representing the graph
+       described by the GRAPH_DESCRIPTION string. Note that this string must
+       be a complete self-contained graph, with its inputs and outputs
+       explicitly defined.  For example if your command line is of the form:
+
+	       ffmpeg -i infile -vf scale=640:360 outfile
+
+       your GRAPH_DESCRIPTION string will need to be of the form:
+
+	       nullsrc,scale=640:360,nullsink
+
+       you may also need to set the nullsrc parameters and add a format filter
+       in order to simulate a specific input file.
+
+FILTERGRAPH DESCRIPTION
+       A filtergraph is a directed graph of connected filters. It can contain
+       cycles, and there can be multiple links between a pair of filters. Each
+       link has one input pad on one side connecting it to one filter from
+       which it takes its input, and one output pad on the other side
+       connecting it to one filter accepting its output.
+
+       Each filter in a filtergraph is an instance of a filter class
+       registered in the application, which defines the features and the
+       number of input and output pads of the filter.
+
+       A filter with no input pads is called a "source", and a filter with no
+       output pads is called a "sink".
+
+   Filtergraph syntax
+       A filtergraph has a textual representation, which is recognized by the
+       -filter/-vf/-af and -filter_complex options in ffmpeg and -vf/-af in
+       ffplay, and by the "avfilter_graph_parse_ptr()" function defined in
+       libavfilter/avfilter.h.
+
+       A filterchain consists of a sequence of connected filters, each one
+       connected to the previous one in the sequence. A filterchain is
+       represented by a list of ","-separated filter descriptions.
+
+       A filtergraph consists of a sequence of filterchains. A sequence of
+       filterchains is represented by a list of ";"-separated filterchain
+       descriptions.
+
+       A filter is represented by a string of the form:
+       [in_link_1]...[in_link_N]filter_name@id=arguments[out_link_1]...[out_link_M]
+
+       filter_name is the name of the filter class of which the described
+       filter is an instance of, and has to be the name of one of the filter
+       classes registered in the program optionally followed by "@id".	The
+       name of the filter class is optionally followed by a string
+       "=arguments".
+
+       arguments is a string which contains the parameters used to initialize
+       the filter instance. It may have one of two forms:
+
+       o   A ':'-separated list of key=value pairs.
+
+       o   A ':'-separated list of value. In this case, the keys are assumed
+	   to be the option names in the order they are declared. E.g. the
+	   "fade" filter declares three options in this order -- type,
+	   start_frame and nb_frames. Then the parameter list in:0:30 means
+	   that the value in is assigned to the option type, 0 to start_frame
+	   and 30 to nb_frames.
+
+       o   A ':'-separated list of mixed direct value and long key=value
+	   pairs. The direct value must precede the key=value pairs, and
+	   follow the same constraints order of the previous point. The
+	   following key=value pairs can be set in any preferred order.
+
+       If the option value itself is a list of items (e.g. the "format" filter
+       takes a list of pixel formats), the items in the list are usually
+       separated by |.
+
+       The list of arguments can be quoted using the character ' as initial
+       and ending mark, and the character \ for escaping the characters within
+       the quoted text; otherwise the argument string is considered terminated
+       when the next special character (belonging to the set []=;,) is
+       encountered.
+
+       A special syntax implemented in the ffmpeg CLI tool allows loading
+       option values from files. This is done be prepending a slash '/' to the
+       option name, then the supplied value is interpreted as a path from
+       which the actual value is loaded. E.g.
+
+	       ffmpeg -i <INPUT> -vf drawtext=/text=/tmp/some_text <OUTPUT>
+
+       will load the text to be drawn from /tmp/some_text. API users wishing
+       to implement a similar feature should use the
+       "avfilter_graph_segment_*()" functions together with custom IO code.
+
+       The name and arguments of the filter are optionally preceded and
+       followed by a list of link labels.  A link label allows one to name a
+       link and associate it to a filter output or input pad. The preceding
+       labels in_link_1 ... in_link_N, are associated to the filter input
+       pads, the following labels out_link_1 ... out_link_M, are associated to
+       the output pads.
+
+       When two link labels with the same name are found in the filtergraph, a
+       link between the corresponding input and output pad is created.
+
+       If an output pad is not labelled, it is linked by default to the first
+       unlabelled input pad of the next filter in the filterchain.  For
+       example in the filterchain
+
+	       nullsrc, split[L1], [L2]overlay, nullsink
+
+       the split filter instance has two output pads, and the overlay filter
+       instance two input pads. The first output pad of split is labelled
+       "L1", the first input pad of overlay is labelled "L2", and the second
+       output pad of split is linked to the second input pad of overlay, which
+       are both unlabelled.
+
+       In a filter description, if the input label of the first filter is not
+       specified, "in" is assumed; if the output label of the last filter is
+       not specified, "out" is assumed.
+
+       In a complete filterchain all the unlabelled filter input and output
+       pads must be connected. A filtergraph is considered valid if all the
+       filter input and output pads of all the filterchains are connected.
+
+       Libavfilter will automatically insert scale filters where format
+       conversion is required. It is possible to specify swscale flags for
+       those automatically inserted scalers by prepending "sws_flags=flags;"
+       to the filtergraph description.
+
+       Here is a BNF description of the filtergraph syntax:
+
+	       <NAME>		  ::= sequence of alphanumeric characters and '_'
+	       <FILTER_NAME>	  ::= <NAME>["@"<NAME>]
+	       <LINKLABEL>	  ::= "[" <NAME> "]"
+	       <LINKLABELS>	  ::= <LINKLABEL> [<LINKLABELS>]
+	       <FILTER_ARGUMENTS> ::= sequence of chars (possibly quoted)
+	       <FILTER> 	  ::= [<LINKLABELS>] <FILTER_NAME> ["=" <FILTER_ARGUMENTS>] [<LINKLABELS>]
+	       <FILTERCHAIN>	  ::= <FILTER> [,<FILTERCHAIN>]
+	       <FILTERGRAPH>	  ::= [sws_flags=<flags>;] <FILTERCHAIN> [;<FILTERGRAPH>]
+
+   Notes on filtergraph escaping
+       Filtergraph description composition entails several levels of escaping.
+       See the "Quoting and escaping" section in the ffmpeg-utils(1) manual
+       for more information about the employed escaping procedure.
+
+       A first level escaping affects the content of each filter option value,
+       which may contain the special character ":" used to separate values, or
+       one of the escaping characters "\'".
+
+       A second level escaping affects the whole filter description, which may
+       contain the escaping characters "\'" or the special characters "[],;"
+       used by the filtergraph description.
+
+       Finally, when you specify a filtergraph on a shell commandline, you
+       need to perform a third level escaping for the shell special characters
+       contained within it.
+
+       For example, consider the following string to be embedded in the
+       drawtext filter description text value:
+
+	       this is a 'string': may contain one, or more, special characters
+
+       This string contains the "'" special escaping character, and the ":"
+       special character, so it needs to be escaped in this way:
+
+	       text=this is a \'string\'\: may contain one, or more, special characters
+
+       A second level of escaping is required when embedding the filter
+       description in a filtergraph description, in order to escape all the
+       filtergraph special characters. Thus the example above becomes:
+
+	       drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
+
+       (note that in addition to the "\'" escaping special characters, also
+       "," needs to be escaped).
+
+       Finally an additional level of escaping is needed when writing the
+       filtergraph description in a shell command, which depends on the
+       escaping rules of the adopted shell. For example, assuming that "\" is
+       special and needs to be escaped with another "\", the previous string
+       will finally result in:
+
+	       -vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
+
+TIMELINE EDITING
+       Some filters support a generic enable option. For the filters
+       supporting timeline editing, this option can be set to an expression
+       which is evaluated before sending a frame to the filter. If the
+       evaluation is non-zero, the filter will be enabled, otherwise the frame
+       will be sent unchanged to the next filter in the filtergraph.
+
+       The expression accepts the following values:
+
+       t   timestamp expressed in seconds, NAN if the input timestamp is
+	   unknown
+
+       n   sequential number of the input frame, starting from 0
+
+       pos the position in the file of the input frame, NAN if unknown
+
+       w
+       h   width and height of the input frame if video
+
+       Additionally, these filters support an enable command that can be used
+       to re-define the expression.
+
+       Like any other filtering option, the enable option follows the same
+       rules.
+
+       For example, to enable a blur filter (smartblur) from 10 seconds to 3
+       minutes, and a curves filter starting at 3 seconds:
+
+	       smartblur = enable='between(t,10,3*60)',
+	       curves	 = enable='gte(t,3)' : preset=cross_process
+
+       See "ffmpeg -filters" to view which filters have timeline support.
+
+CHANGING OPTIONS AT RUNTIME WITH A COMMAND
+       Some options can be changed during the operation of the filter using a
+       command. These options are marked 'T' on the output of ffmpeg -h
+       filter=<name of filter>.  The name of the command is the name of the
+       option and the argument is the new value.
+
+OPTIONS FOR FILTERS WITH SEVERAL INPUTS
+       Some filters with several inputs support a common set of options.
+       These options can only be set by name, not with the short notation.
+
+       eof_action
+	   The action to take when EOF is encountered on the secondary input;
+	   it accepts one of the following values:
+
+	   repeat
+	       Repeat the last frame (the default).
+
+	   endall
+	       End both streams.
+
+	   pass
+	       Pass the main input through.
+
+       shortest
+	   If set to 1, force the output to terminate when the shortest input
+	   terminates. Default value is 0.
+
+       repeatlast
+	   If set to 1, force the filter to extend the last frame of secondary
+	   streams until the end of the primary stream. A value of 0 disables
+	   this behavior.  Default value is 1.
+
+       ts_sync_mode
+	   How strictly to sync streams based on secondary input timestamps;
+	   it accepts one of the following values:
+
+	   default
+	       Frame from secondary input with the nearest lower or equal
+	       timestamp to the primary input frame.
+
+	   nearest
+	       Frame from secondary input with the absolute nearest timestamp
+	       to the primary input frame.
+
+AUDIO FILTERS
+       When you configure your FFmpeg build, you can disable any of the
+       existing filters using "--disable-filters".  The configure output will
+       show the audio filters included in your build.
+
+       Below is a description of the currently available audio filters.
+
+   acompressor
+       A compressor is mainly used to reduce the dynamic range of a signal.
+       Especially modern music is mostly compressed at a high ratio to improve
+       the overall loudness. It's done to get the highest attention of a
+       listener, "fatten" the sound and bring more "power" to the track.  If a
+       signal is compressed too much it may sound dull or "dead" afterwards or
+       it may start to "pump" (which could be a powerful effect but can also
+       destroy a track completely).  The right compression is the key to reach
+       a professional sound and is the high art of mixing and mastering.
+       Because of its complex settings it may take a long time to get the
+       right feeling for this kind of effect.
+
+       Compression is done by detecting the volume above a chosen level
+       "threshold" and dividing it by the factor set with "ratio".  So if you
+       set the threshold to -12dB and your signal reaches -6dB a ratio of 2:1
+       will result in a signal at -9dB. Because an exact manipulation of the
+       signal would cause distortion of the waveform the reduction can be
+       levelled over the time. This is done by setting "Attack" and "Release".
+       "attack" determines how long the signal has to rise above the threshold
+       before any reduction will occur and "release" sets the time the signal
+       has to fall below the threshold to reduce the reduction again. Shorter
+       signals than the chosen attack time will be left untouched.  The
+       overall reduction of the signal can be made up afterwards with the
+       "makeup" setting. So compressing the peaks of a signal about 6dB and
+       raising the makeup to this level results in a signal twice as loud than
+       the source. To gain a softer entry in the compression the "knee"
+       flattens the hard edge at the threshold in the range of the chosen
+       decibels.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input gain. Default is 1. Range is between 0.015625 and 64.
+
+       mode
+	   Set mode of compressor operation. Can be "upward" or "downward".
+	   Default is "downward".
+
+       threshold
+	   If a signal of stream rises above this level it will affect the
+	   gain reduction.  By default it is 0.125. Range is between
+	   0.00097563 and 1.
+
+       ratio
+	   Set a ratio by which the signal is reduced. 1:2 means that if the
+	   level rose 4dB above the threshold, it will be only 2dB above after
+	   the reduction.  Default is 2. Range is between 1 and 20.
+
+       attack
+	   Amount of milliseconds the signal has to rise above the threshold
+	   before gain reduction starts. Default is 20. Range is between 0.01
+	   and 2000.
+
+       release
+	   Amount of milliseconds the signal has to fall below the threshold
+	   before reduction is decreased again. Default is 250. Range is
+	   between 0.01 and 9000.
+
+       makeup
+	   Set the amount by how much signal will be amplified after
+	   processing.	Default is 1. Range is from 1 to 64.
+
+       knee
+	   Curve the sharp knee around the threshold to enter gain reduction
+	   more softly.  Default is 2.82843. Range is between 1 and 8.
+
+       link
+	   Choose if the "average" level between all channels of input stream
+	   or the louder("maximum") channel of input stream affects the
+	   reduction. Default is "average".
+
+       detection
+	   Should the exact signal be taken in case of "peak" or an RMS one in
+	   case of "rms". Default is "rms" which is mostly smoother.
+
+       mix How much to use compressed signal in output. Default is 1.  Range
+	   is between 0 and 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   acontrast
+       Simple audio dynamic range compression/expansion filter.
+
+       The filter accepts the following options:
+
+       contrast
+	   Set contrast. Default is 33. Allowed range is between 0 and 100.
+
+   acopy
+       Copy the input audio source unchanged to the output. This is mainly
+       useful for testing purposes.
+
+   acrossfade
+       Apply cross fade from one input audio stream to another input audio
+       stream.	The cross fade is applied for specified duration near the end
+       of first stream.
+
+       The filter accepts the following options:
+
+       nb_samples, ns
+	   Specify the number of samples for which the cross fade effect has
+	   to last.  At the end of the cross fade effect the first input audio
+	   will be completely silent. Default is 44100.
+
+       duration, d
+	   Specify the duration of the cross fade effect. See the Time
+	   duration section in the ffmpeg-utils(1) manual for the accepted
+	   syntax.  By default the duration is determined by nb_samples.  If
+	   set this option is used instead of nb_samples.
+
+       overlap, o
+	   Should first stream end overlap with second stream start. Default
+	   is enabled.
+
+       curve1
+	   Set curve for cross fade transition for first stream.
+
+       curve2
+	   Set curve for cross fade transition for second stream.
+
+	   For description of available curve types see afade filter
+	   description.
+
+       Examples
+
+       o   Cross fade from one input to another:
+
+		   ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:c1=exp:c2=exp output.flac
+
+       o   Cross fade from one input to another but without overlapping:
+
+		   ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:o=0:c1=exp:c2=exp output.flac
+
+   acrossover
+       Split audio stream into several bands.
+
+       This filter splits audio stream into two or more frequency ranges.
+       Summing all streams back will give flat output.
+
+       The filter accepts the following options:
+
+       split
+	   Set split frequencies. Those must be positive and increasing.
+
+       order
+	   Set filter order for each band split. This controls filter roll-off
+	   or steepness of filter transfer function.  Available values are:
+
+	   2nd 12 dB per octave.
+
+	   4th 24 dB per octave.
+
+	   6th 36 dB per octave.
+
+	   8th 48 dB per octave.
+
+	   10th
+	       60 dB per octave.
+
+	   12th
+	       72 dB per octave.
+
+	   14th
+	       84 dB per octave.
+
+	   16th
+	       96 dB per octave.
+
+	   18th
+	       108 dB per octave.
+
+	   20th
+	       120 dB per octave.
+
+	   Default is 4th.
+
+       level
+	   Set input gain level. Allowed range is from 0 to 1. Default value
+	   is 1.
+
+       gains
+	   Set output gain for each band. Default value is 1 for all bands.
+
+       precision
+	   Set which precision to use when processing samples.
+
+	   auto
+	       Auto pick internal sample format depending on other filters.
+
+	   float
+	       Always use single-floating point precision sample format.
+
+	   double
+	       Always use double-floating point precision sample format.
+
+	   Default value is "auto".
+
+       Examples
+
+       o   Split input audio stream into two bands (low and high) with split
+	   frequency of 1500 Hz, each band will be in separate stream:
+
+		   ffmpeg -i in.flac -filter_complex 'acrossover=split=1500[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav
+
+       o   Same as above, but with higher filter order:
+
+		   ffmpeg -i in.flac -filter_complex 'acrossover=split=1500:order=8th[LOW][HIGH]' -map '[LOW]' low.wav -map '[HIGH]' high.wav
+
+       o   Same as above, but also with additional middle band (frequencies
+	   between 1500 and 8000):
+
+		   ffmpeg -i in.flac -filter_complex 'acrossover=split=1500 8000:order=8th[LOW][MID][HIGH]' -map '[LOW]' low.wav -map '[MID]' mid.wav -map '[HIGH]' high.wav
+
+   acrusher
+       Reduce audio bit resolution.
+
+       This filter is bit crusher with enhanced functionality. A bit crusher
+       is used to audibly reduce number of bits an audio signal is sampled
+       with. This doesn't change the bit depth at all, it just produces the
+       effect. Material reduced in bit depth sounds more harsh and "digital".
+       This filter is able to even round to continuous values instead of
+       discrete bit depths.  Additionally it has a D/C offset which results in
+       different crushing of the lower and the upper half of the signal.  An
+       Anti-Aliasing setting is able to produce "softer" crushing sounds.
+
+       Another feature of this filter is the logarithmic mode.	This setting
+       switches from linear distances between bits to logarithmic ones.  The
+       result is a much more "natural" sounding crusher which doesn't gate low
+       signals for example. The human ear has a logarithmic perception, so
+       this kind of crushing is much more pleasant.  Logarithmic crushing is
+       also able to get anti-aliased.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set level in.
+
+       level_out
+	   Set level out.
+
+       bits
+	   Set bit reduction.
+
+       mix Set mixing amount.
+
+       mode
+	   Can be linear: "lin" or logarithmic: "log".
+
+       dc  Set DC.
+
+       aa  Set anti-aliasing.
+
+       samples
+	   Set sample reduction.
+
+       lfo Enable LFO. By default disabled.
+
+       lforange
+	   Set LFO range.
+
+       lforate
+	   Set LFO rate.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   acue
+       Delay audio filtering until a given wallclock timestamp. See the cue
+       filter.
+
+   adeclick
+       Remove impulsive noise from input audio.
+
+       Samples detected as impulsive noise are replaced by interpolated
+       samples using autoregressive modelling.
+
+       window, w
+	   Set window size, in milliseconds. Allowed range is from 10 to 100.
+	   Default value is 55 milliseconds.  This sets size of window which
+	   will be processed at once.
+
+       overlap, o
+	   Set window overlap, in percentage of window size. Allowed range is
+	   from 50 to 95. Default value is 75 percent.	Setting this to a very
+	   high value increases impulsive noise removal but makes whole
+	   process much slower.
+
+       arorder, a
+	   Set autoregression order, in percentage of window size. Allowed
+	   range is from 0 to 25. Default value is 2 percent. This option also
+	   controls quality of interpolated samples using neighbour good
+	   samples.
+
+       threshold, t
+	   Set threshold value. Allowed range is from 1 to 100.  Default value
+	   is 2.  This controls the strength of impulsive noise which is going
+	   to be removed.  The lower value, the more samples will be detected
+	   as impulsive noise.
+
+       burst, b
+	   Set burst fusion, in percentage of window size. Allowed range is 0
+	   to 10. Default value is 2.  If any two samples detected as noise
+	   are spaced less than this value then any sample between those two
+	   samples will be also detected as noise.
+
+       method, m
+	   Set overlap method.
+
+	   It accepts the following values:
+
+	   add, a
+	       Select overlap-add method. Even not interpolated samples are
+	       slightly changed with this method.
+
+	   save, s
+	       Select overlap-save method. Not interpolated samples remain
+	       unchanged.
+
+	   Default value is "a".
+
+   adeclip
+       Remove clipped samples from input audio.
+
+       Samples detected as clipped are replaced by interpolated samples using
+       autoregressive modelling.
+
+       window, w
+	   Set window size, in milliseconds. Allowed range is from 10 to 100.
+	   Default value is 55 milliseconds.  This sets size of window which
+	   will be processed at once.
+
+       overlap, o
+	   Set window overlap, in percentage of window size. Allowed range is
+	   from 50 to 95. Default value is 75 percent.
+
+       arorder, a
+	   Set autoregression order, in percentage of window size. Allowed
+	   range is from 0 to 25. Default value is 8 percent. This option also
+	   controls quality of interpolated samples using neighbour good
+	   samples.
+
+       threshold, t
+	   Set threshold value. Allowed range is from 1 to 100.  Default value
+	   is 10. Higher values make clip detection less aggressive.
+
+       hsize, n
+	   Set size of histogram used to detect clips. Allowed range is from
+	   100 to 9999.  Default value is 1000. Higher values make clip
+	   detection less aggressive.
+
+       method, m
+	   Set overlap method.
+
+	   It accepts the following values:
+
+	   add, a
+	       Select overlap-add method. Even not interpolated samples are
+	       slightly changed with this method.
+
+	   save, s
+	       Select overlap-save method. Not interpolated samples remain
+	       unchanged.
+
+	   Default value is "a".
+
+   adecorrelate
+       Apply decorrelation to input audio stream.
+
+       The filter accepts the following options:
+
+       stages
+	   Set decorrelation stages of filtering. Allowed range is from 1 to
+	   16. Default value is 6.
+
+       seed
+	   Set random seed used for setting delay in samples across channels.
+
+   adelay
+       Delay one or more audio channels.
+
+       Samples in delayed channel are filled with silence.
+
+       The filter accepts the following option:
+
+       delays
+	   Set list of delays in milliseconds for each channel separated by
+	   '|'.  Unused delays will be silently ignored. If number of given
+	   delays is smaller than number of channels all remaining channels
+	   will not be delayed.  If you want to delay exact number of samples,
+	   append 'S' to number.  If you want instead to delay in seconds,
+	   append 's' to number.
+
+       all Use last set delay for all remaining channels. By default is
+	   disabled.  This option if enabled changes how option "delays" is
+	   interpreted.
+
+       Examples
+
+       o   Delay first channel by 1.5 seconds, the third channel by 0.5
+	   seconds and leave the second channel (and any other channels that
+	   may be present) unchanged.
+
+		   adelay=1500|0|500
+
+       o   Delay second channel by 500 samples, the third channel by 700
+	   samples and leave the first channel (and any other channels that
+	   may be present) unchanged.
+
+		   adelay=0|500S|700S
+
+       o   Delay all channels by same number of samples:
+
+		   adelay=delays=64S:all=1
+
+   adenorm
+       Remedy denormals in audio by adding extremely low-level noise.
+
+       This filter shall be placed before any filter that can produce
+       denormals.
+
+       A description of the accepted parameters follows.
+
+       level
+	   Set level of added noise in dB. Default is "-351".  Allowed range
+	   is from -451 to -90.
+
+       type
+	   Set type of added noise.
+
+	   dc  Add DC signal.
+
+	   ac  Add AC signal.
+
+	   square
+	       Add square signal.
+
+	   pulse
+	       Add pulse signal.
+
+	   Default is "dc".
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   aderivative, aintegral
+       Compute derivative/integral of audio stream.
+
+       Applying both filters one after another produces original audio.
+
+   adrc
+       Apply spectral dynamic range controller filter to input audio stream.
+
+       A description of the accepted options follows.
+
+       transfer
+	   Set the transfer expression.
+
+	   The expression can contain the following constants:
+
+	   ch  current channel number
+
+	   sn  current sample number
+
+	   nb_channels
+	       number of channels
+
+	   t   timestamp expressed in seconds
+
+	   sr  sample rate
+
+	   p   current frequency power value, in dB
+
+	   f   current frequency in Hz
+
+	   Default value is "p".
+
+       attack
+	   Set the attack in milliseconds. Default is 50 milliseconds.
+	   Allowed range is from 1 to 1000 milliseconds.
+
+       release
+	   Set the release in milliseconds. Default is 100 milliseconds.
+	   Allowed range is from 5 to 2000 milliseconds.
+
+       channels
+	   Set which channels to filter, by default "all" channels in audio
+	   stream are filtered.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Apply spectral compression to all frequencies with threshold of -50
+	   dB and 1:6 ratio:
+
+		   adrc=transfer='if(gt(p,-50),-50+(p-(-50))/6,p)':attack=50:release=100
+
+       o   Similar to above but with 1:2 ratio and filtering only front center
+	   channel:
+
+		   adrc=transfer='if(gt(p,-50),-50+(p-(-50))/2,p)':attack=50:release=100:channels=FC
+
+       o   Apply spectral noise gate to all frequencies with threshold of -85
+	   dB and with short attack time and short release time:
+
+		   adrc=transfer='if(lte(p,-85),p-800,p)':attack=1:release=5
+
+       o   Apply spectral expansion to all frequencies with threshold of -10
+	   dB and 1:2 ratio:
+
+		   adrc=transfer='if(lt(p,-10),-10+(p-(-10))*2,p)':attack=50:release=100
+
+       o   Apply limiter to max -60 dB to all frequencies, with attack of 2 ms
+	   and release of 10 ms:
+
+		   adrc=transfer='min(p,-60)':attack=2:release=10
+
+   adynamicequalizer
+       Apply dynamic equalization to input audio stream.
+
+       A description of the accepted options follows.
+
+       threshold
+	   Set the detection threshold used to trigger equalization.
+	   Threshold detection is using bandpass filter.  Default value is 0.
+	   Allowed range is from 0 to 100.
+
+       dfrequency
+	   Set the detection frequency in Hz used for bandpass filter used to
+	   trigger equalization.  Default value is 1000 Hz. Allowed range is
+	   between 2 and 1000000 Hz.
+
+       dqfactor
+	   Set the detection resonance factor for bandpass filter used to
+	   trigger equalization.  Default value is 1. Allowed range is from
+	   0.001 to 1000.
+
+       tfrequency
+	   Set the target frequency of equalization filter.  Default value is
+	   1000 Hz. Allowed range is between 2 and 1000000 Hz.
+
+       tqfactor
+	   Set the target resonance factor for target equalization filter.
+	   Default value is 1. Allowed range is from 0.001 to 1000.
+
+       attack
+	   Set the amount of milliseconds the signal from detection has to
+	   rise above the detection threshold before equalization starts.
+	   Default is 20. Allowed range is between 1 and 2000.
+
+       release
+	   Set the amount of milliseconds the signal from detection has to
+	   fall below the detection threshold before equalization ends.
+	   Default is 200. Allowed range is between 1 and 2000.
+
+       ratio
+	   Set the ratio by which the equalization gain is raised.  Default is
+	   1. Allowed range is between 0 and 30.
+
+       makeup
+	   Set the makeup offset by which the equalization gain is raised.
+	   Default is 0. Allowed range is between 0 and 100.
+
+       range
+	   Set the max allowed cut/boost amount. Default is 50.  Allowed range
+	   is from 1 to 200.
+
+       mode
+	   Set the mode of filter operation, can be one of the following:
+
+	   listen
+	       Output only isolated bandpass signal.
+
+	   cut Cut frequencies above detection threshold.
+
+	   boost
+	       Boost frequencies bellow detection threshold.
+
+	   Default mode is cut.
+
+       tftype
+	   Set the type of target filter, can be one of the following:
+
+	   bell
+	   lowshelf
+	   highshelf
+
+	   Default type is bell.
+
+       direction
+	   Set processing direction relative to threshold.
+
+	   downward
+	       Boost/Cut if threshold is higher/lower than detected volume.
+
+	   upward
+	       Boost/Cut if threshold is lower/higher than detected volume.
+
+	   Default direction is downward.
+
+       auto
+	   Automatically gather threshold from detection filter. By default is
+	   disabled.  This option is useful to detect threshold in certain
+	   time frame of input audio stream, in such case option value is
+	   changed at runtime.
+
+	   Available values are:
+
+	   disabled
+	       Disable using automatically gathered threshold value.
+
+	   off Stop picking threshold value.
+
+	   on  Start picking threshold value.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   adynamicsmooth
+       Apply dynamic smoothing to input audio stream.
+
+       A description of the accepted options follows.
+
+       sensitivity
+	   Set an amount of sensitivity to frequency fluctations. Default is
+	   2.  Allowed range is from 0 to 1e+06.
+
+       basefreq
+	   Set a base frequency for smoothing. Default value is 22050.
+	   Allowed range is from 2 to 1e+06.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   aecho
+       Apply echoing to the input audio.
+
+       Echoes are reflected sound and can occur naturally amongst mountains
+       (and sometimes large buildings) when talking or shouting; digital echo
+       effects emulate this behaviour and are often used to help fill out the
+       sound of a single instrument or vocal. The time difference between the
+       original signal and the reflection is the "delay", and the loudness of
+       the reflected signal is the "decay".  Multiple echoes can have
+       different delays and decays.
+
+       A description of the accepted parameters follows.
+
+       in_gain
+	   Set input gain of reflected signal. Default is 0.6.
+
+       out_gain
+	   Set output gain of reflected signal. Default is 0.3.
+
+       delays
+	   Set list of time intervals in milliseconds between original signal
+	   and reflections separated by '|'. Allowed range for each "delay" is
+	   "(0 - 90000.0]".  Default is 1000.
+
+       decays
+	   Set list of loudness of reflected signals separated by '|'.
+	   Allowed range for each "decay" is "(0 - 1.0]".  Default is 0.5.
+
+       Examples
+
+       o   Make it sound as if there are twice as many instruments as are
+	   actually playing:
+
+		   aecho=0.8:0.88:60:0.4
+
+       o   If delay is very short, then it sounds like a (metallic) robot
+	   playing music:
+
+		   aecho=0.8:0.88:6:0.4
+
+       o   A longer delay will sound like an open air concert in the
+	   mountains:
+
+		   aecho=0.8:0.9:1000:0.3
+
+       o   Same as above but with one more mountain:
+
+		   aecho=0.8:0.9:1000|1800:0.3|0.25
+
+   aemphasis
+       Audio emphasis filter creates or restores material directly taken from
+       LPs or emphased CDs with different filter curves. E.g. to store music
+       on vinyl the signal has to be altered by a filter first to even out the
+       disadvantages of this recording medium.	Once the material is played
+       back the inverse filter has to be applied to restore the distortion of
+       the frequency response.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input gain.
+
+       level_out
+	   Set output gain.
+
+       mode
+	   Set filter mode. For restoring material use "reproduction" mode,
+	   otherwise use "production" mode. Default is "reproduction" mode.
+
+       type
+	   Set filter type. Selects medium. Can be one of the following:
+
+	   col select Columbia.
+
+	   emi select EMI.
+
+	   bsi select BSI (78RPM).
+
+	   riaa
+	       select RIAA.
+
+	   cd  select Compact Disc (CD).
+
+	   50fm
+	       select 50Xs (FM).
+
+	   75fm
+	       select 75Xs (FM).
+
+	   50kf
+	       select 50Xs (FM-KF).
+
+	   75kf
+	       select 75Xs (FM-KF).
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   aeval
+       Modify an audio signal according to the specified expressions.
+
+       This filter accepts one or more expressions (one for each channel),
+       which are evaluated and used to modify a corresponding audio signal.
+
+       It accepts the following parameters:
+
+       exprs
+	   Set the '|'-separated expressions list for each separate channel.
+	   If the number of input channels is greater than the number of
+	   expressions, the last specified expression is used for the
+	   remaining output channels.
+
+       channel_layout, c
+	   Set output channel layout. If not specified, the channel layout is
+	   specified by the number of expressions. If set to same, it will use
+	   by default the same input channel layout.
+
+       Each expression in exprs can contain the following constants and
+       functions:
+
+       ch  channel number of the current expression
+
+       n   number of the evaluated sample, starting from 0
+
+       s   sample rate
+
+       t   time of the evaluated sample expressed in seconds
+
+       nb_in_channels
+       nb_out_channels
+	   input and output number of channels
+
+       val(CH)
+	   the value of input channel with number CH
+
+       Note: this filter is slow. For faster processing you should use a
+       dedicated filter.
+
+       Examples
+
+       o   Half volume:
+
+		   aeval=val(ch)/2:c=same
+
+       o   Invert phase of the second channel:
+
+		   aeval=val(0)|-val(1)
+
+   aexciter
+       An exciter is used to produce high sound that is not present in the
+       original signal. This is done by creating harmonic distortions of the
+       signal which are restricted in range and added to the original signal.
+       An Exciter raises the upper end of an audio signal without simply
+       raising the higher frequencies like an equalizer would do to create a
+       more "crisp" or "brilliant" sound.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input level prior processing of signal.	Allowed range is from
+	   0 to 64.  Default value is 1.
+
+       level_out
+	   Set output level after processing of signal.  Allowed range is from
+	   0 to 64.  Default value is 1.
+
+       amount
+	   Set the amount of harmonics added to original signal.  Allowed
+	   range is from 0 to 64.  Default value is 1.
+
+       drive
+	   Set the amount of newly created harmonics.  Allowed range is from
+	   0.1 to 10.  Default value is 8.5.
+
+       blend
+	   Set the octave of newly created harmonics.  Allowed range is from
+	   -10 to 10.  Default value is 0.
+
+       freq
+	   Set the lower frequency limit of producing harmonics in Hz.
+	   Allowed range is from 2000 to 12000 Hz.  Default is 7500 Hz.
+
+       ceil
+	   Set the upper frequency limit of producing harmonics.  Allowed
+	   range is from 9999 to 20000 Hz.  If value is lower than 10000 Hz no
+	   limit is applied.
+
+       listen
+	   Mute the original signal and output only added harmonics.  By
+	   default is disabled.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   afade
+       Apply fade-in/out effect to input audio.
+
+       A description of the accepted parameters follows.
+
+       type, t
+	   Specify the effect type, can be either "in" for fade-in, or "out"
+	   for a fade-out effect. Default is "in".
+
+       start_sample, ss
+	   Specify the number of the start sample for starting to apply the
+	   fade effect. Default is 0.
+
+       nb_samples, ns
+	   Specify the number of samples for which the fade effect has to
+	   last. At the end of the fade-in effect the output audio will have
+	   the same volume as the input audio, at the end of the fade-out
+	   transition the output audio will be silence. Default is 44100.
+
+       start_time, st
+	   Specify the start time of the fade effect. Default is 0.  The value
+	   must be specified as a time duration; see the Time duration section
+	   in the ffmpeg-utils(1) manual for the accepted syntax.  If set this
+	   option is used instead of start_sample.
+
+       duration, d
+	   Specify the duration of the fade effect. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.  At
+	   the end of the fade-in effect the output audio will have the same
+	   volume as the input audio, at the end of the fade-out transition
+	   the output audio will be silence.  By default the duration is
+	   determined by nb_samples.  If set this option is used instead of
+	   nb_samples.
+
+       curve
+	   Set curve for fade transition.
+
+	   It accepts the following values:
+
+	   tri select triangular, linear slope (default)
+
+	   qsin
+	       select quarter of sine wave
+
+	   hsin
+	       select half of sine wave
+
+	   esin
+	       select exponential sine wave
+
+	   log select logarithmic
+
+	   ipar
+	       select inverted parabola
+
+	   qua select quadratic
+
+	   cub select cubic
+
+	   squ select square root
+
+	   cbr select cubic root
+
+	   par select parabola
+
+	   exp select exponential
+
+	   iqsin
+	       select inverted quarter of sine wave
+
+	   ihsin
+	       select inverted half of sine wave
+
+	   dese
+	       select double-exponential seat
+
+	   desi
+	       select double-exponential sigmoid
+
+	   losi
+	       select logistic sigmoid
+
+	   sinc
+	       select sine cardinal function
+
+	   isinc
+	       select inverted sine cardinal function
+
+	   nofade
+	       no fade applied
+
+       silence
+	   Set the initial gain for fade-in or final gain for fade-out.
+	   Default value is 0.0.
+
+       unity
+	   Set the initial gain for fade-out or final gain for fade-in.
+	   Default value is 1.0.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Fade in first 15 seconds of audio:
+
+		   afade=t=in:ss=0:d=15
+
+       o   Fade out last 25 seconds of a 900 seconds audio:
+
+		   afade=t=out:st=875:d=25
+
+   afftdn
+       Denoise audio samples with FFT.
+
+       A description of the accepted parameters follows.
+
+       noise_reduction, nr
+	   Set the noise reduction in dB, allowed range is 0.01 to 97.
+	   Default value is 12 dB.
+
+       noise_floor, nf
+	   Set the noise floor in dB, allowed range is -80 to -20.  Default
+	   value is -50 dB.
+
+       noise_type, nt
+	   Set the noise type.
+
+	   It accepts the following values:
+
+	   white, w
+	       Select white noise.
+
+	   vinyl, v
+	       Select vinyl noise.
+
+	   shellac, s
+	       Select shellac noise.
+
+	   custom, c
+	       Select custom noise, defined in "bn" option.
+
+	       Default value is white noise.
+
+       band_noise, bn
+	   Set custom band noise profile for every one of 15 bands.  Bands are
+	   separated by ' ' or '|'.
+
+       residual_floor, rf
+	   Set the residual floor in dB, allowed range is -80 to -20.  Default
+	   value is -38 dB.
+
+       track_noise, tn
+	   Enable noise floor tracking. By default is disabled.  With this
+	   enabled, noise floor is automatically adjusted.
+
+       track_residual, tr
+	   Enable residual tracking. By default is disabled.
+
+       output_mode, om
+	   Set the output mode.
+
+	   It accepts the following values:
+
+	   input, i
+	       Pass input unchanged.
+
+	   output, o
+	       Pass noise filtered out.
+
+	   noise, n
+	       Pass only noise.
+
+	       Default value is output.
+
+       adaptivity, ad
+	   Set the adaptivity factor, used how fast to adapt gains adjustments
+	   per each frequency bin. Value 0 enables instant adaptation, while
+	   higher values react much slower.  Allowed range is from 0 to 1.
+	   Default value is 0.5.
+
+       floor_offset, fo
+	   Set the noise floor offset factor. This option is used to adjust
+	   offset applied to measured noise floor. It is only effective when
+	   noise floor tracking is enabled.  Allowed range is from -2.0 to
+	   2.0. Default value is 1.0.
+
+       noise_link, nl
+	   Set the noise link used for multichannel audio.
+
+	   It accepts the following values:
+
+	   none
+	       Use unchanged channel's noise floor.
+
+	   min Use measured min noise floor of all channels.
+
+	   max Use measured max noise floor of all channels.
+
+	   average
+	       Use measured average noise floor of all channels.
+
+	       Default value is min.
+
+       band_multiplier, bm
+	   Set the band multiplier factor, used how much to spread bands
+	   across frequency bins.  Allowed range is from 0.2 to 5. Default
+	   value is 1.25.
+
+       sample_noise, sn
+	   Toggle capturing and measurement of noise profile from input audio.
+
+	   It accepts the following values:
+
+	   start, begin
+	       Start sample noise capture.
+
+	   stop, end
+	       Stop sample noise capture and measure new noise band profile.
+
+	       Default value is "none".
+
+       gain_smooth, gs
+	   Set gain smooth spatial radius, used to smooth gains applied to
+	   each frequency bin.	Useful to reduce random music noise artefacts.
+	   Higher values increases smoothing of gains.	Allowed range is from
+	   0 to 50.  Default value is 0.
+
+       Commands
+
+       This filter supports the some above mentioned options as commands.
+
+       Examples
+
+       o   Reduce white noise by 10dB, and use previously measured noise floor
+	   of -40dB:
+
+		   afftdn=nr=10:nf=-40
+
+       o   Reduce white noise by 10dB, also set initial noise floor to -80dB
+	   and enable automatic tracking of noise floor so noise floor will
+	   gradually change during processing:
+
+		   afftdn=nr=10:nf=-80:tn=1
+
+       o   Reduce noise by 20dB, using noise floor of -40dB and using commands
+	   to take noise profile of first 0.4 seconds of input audio:
+
+		   asendcmd=0.0 afftdn sn start,asendcmd=0.4 afftdn sn stop,afftdn=nr=20:nf=-40
+
+   afftfilt
+       Apply arbitrary expressions to samples in frequency domain.
+
+       real
+	   Set frequency domain real expression for each separate channel
+	   separated by '|'. Default is "re".  If the number of input channels
+	   is greater than the number of expressions, the last specified
+	   expression is used for the remaining output channels.
+
+       imag
+	   Set frequency domain imaginary expression for each separate channel
+	   separated by '|'. Default is "im".
+
+	   Each expression in real and imag can contain the following
+	   constants and functions:
+
+	   sr  sample rate
+
+	   b   current frequency bin number
+
+	   nb  number of available bins
+
+	   ch  channel number of the current expression
+
+	   chs number of channels
+
+	   pts current frame pts
+
+	   re  current real part of frequency bin of current channel
+
+	   im  current imaginary part of frequency bin of current channel
+
+	   real(b, ch)
+	       Return the value of real part of frequency bin at location
+	       (bin,channel)
+
+	   imag(b, ch)
+	       Return the value of imaginary part of frequency bin at location
+	       (bin,channel)
+
+       win_size
+	   Set window size. Allowed range is from 16 to 131072.  Default is
+	   4096
+
+       win_func
+	   Set window function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hann, hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default is "hann".
+
+       overlap
+	   Set window overlap. If set to 1, the recommended overlap for
+	   selected window function will be picked. Default is 0.75.
+
+       Examples
+
+       o   Leave almost only low frequencies in audio:
+
+		   afftfilt="'real=re * (1-clip((b/nb)*b,0,1))':imag='im * (1-clip((b/nb)*b,0,1))'"
+
+       o   Apply robotize effect:
+
+		   afftfilt="real='hypot(re,im)*sin(0)':imag='hypot(re,im)*cos(0)':win_size=512:overlap=0.75"
+
+       o   Apply whisper effect:
+
+		   afftfilt="real='hypot(re,im)*cos((random(0)*2-1)*2*3.14)':imag='hypot(re,im)*sin((random(1)*2-1)*2*3.14)':win_size=128:overlap=0.8"
+
+       o   Apply phase shift:
+
+		   afftfilt="real=re*cos(1)-im*sin(1):imag=re*sin(1)+im*cos(1)"
+
+   afir
+       Apply an arbitrary Finite Impulse Response filter.
+
+       This filter is designed for applying long FIR filters, up to 60 seconds
+       long.
+
+       It can be used as component for digital crossover filters, room
+       equalization, cross talk cancellation, wavefield synthesis,
+       auralization, ambiophonics, ambisonics and spatialization.
+
+       This filter uses the streams higher than first one as FIR coefficients.
+       If the non-first stream holds a single channel, it will be used for all
+       input channels in the first stream, otherwise the number of channels in
+       the non-first stream must be same as the number of channels in the
+       first stream.
+
+       It accepts the following parameters:
+
+       dry Set dry gain. This sets input gain.
+
+       wet Set wet gain. This sets final output gain.
+
+       length
+	   Set Impulse Response filter length. Default is 1, which means whole
+	   IR is processed.
+
+       gtype
+	   Enable applying gain measured from power of IR.
+
+	   Set which approach to use for auto gain measurement.
+
+	   none
+	       Do not apply any gain.
+
+	   peak
+	       select peak gain, very conservative approach. This is default
+	       value.
+
+	   dc  select DC gain, limited application.
+
+	   gn  select gain to noise approach, this is most popular one.
+
+	   ac  select AC gain.
+
+	   rms select RMS gain.
+
+       irgain
+	   Set gain to be applied to IR coefficients before filtering.
+	   Allowed range is 0 to 1. This gain is applied after any gain
+	   applied with gtype option.
+
+       irfmt
+	   Set format of IR stream. Can be "mono" or "input".  Default is
+	   "input".
+
+       maxir
+	   Set max allowed Impulse Response filter duration in seconds.
+	   Default is 30 seconds.  Allowed range is 0.1 to 60 seconds.
+
+       response
+	   Show IR frequency response, magnitude(magenta), phase(green) and
+	   group delay(yellow) in additional video stream.  By default it is
+	   disabled.
+
+       channel
+	   Set for which IR channel to display frequency response. By default
+	   is first channel displayed. This option is used only when response
+	   is enabled.
+
+       size
+	   Set video stream size. This option is used only when response is
+	   enabled.
+
+       rate
+	   Set video stream frame rate. This option is used only when response
+	   is enabled.
+
+       minp
+	   Set minimal partition size used for convolution. Default is 8192.
+	   Allowed range is from 1 to 65536.  Lower values decreases latency
+	   at cost of higher CPU usage.
+
+       maxp
+	   Set maximal partition size used for convolution. Default is 8192.
+	   Allowed range is from 8 to 65536.  Lower values may increase CPU
+	   usage.
+
+       nbirs
+	   Set number of input impulse responses streams which will be
+	   switchable at runtime.  Allowed range is from 1 to 32. Default is
+	   1.
+
+       ir  Set IR stream which will be used for convolution, starting from 0,
+	   should always be lower than supplied value by "nbirs" option.
+	   Default is 0.  This option can be changed at runtime via commands.
+
+       precision
+	   Set which precision to use when processing samples.
+
+	   auto
+	       Auto pick internal sample format depending on other filters.
+
+	   float
+	       Always use single-floating point precision sample format.
+
+	   double
+	       Always use double-floating point precision sample format.
+
+	   Default value is auto.
+
+       Examples
+
+       o   Apply reverb to stream using mono IR file as second input, complete
+	   command using ffmpeg:
+
+		   ffmpeg -i input.wav -i middle_tunnel_1way_mono.wav -lavfi afir output.wav
+
+       o   Apply true stereo processing given input stereo stream, and two
+	   stereo impulse responses for left and right channel, the impulse
+	   response files are files with names l_ir.wav and r_ir.wav:
+
+		   "pan=4C|c0=FL|c1=FL|c2=FR|c3=FR[a];amovie=l_ir.wav[LIR];amovie=r_ir.wav[RIR];[LIR][RIR]amerge[ir];[a][ir]afir=irfmt=input:gtype=gn:irgain=-5dB,pan=stereo|FL<c0+c2|FR<c1+c3"
+
+   aformat
+       Set output format constraints for the input audio. The framework will
+       negotiate the most appropriate format to minimize conversions.
+
+       It accepts the following parameters:
+
+       sample_fmts, f
+	   A '|'-separated list of requested sample formats.
+
+       sample_rates, r
+	   A '|'-separated list of requested sample rates.
+
+       channel_layouts, cl
+	   A '|'-separated list of requested channel layouts.
+
+	   See the Channel Layout section in the ffmpeg-utils(1) manual for
+	   the required syntax.
+
+       If a parameter is omitted, all values are allowed.
+
+       Force the output to either unsigned 8-bit or signed 16-bit stereo
+
+	       aformat=sample_fmts=u8|s16:channel_layouts=stereo
+
+   afreqshift
+       Apply frequency shift to input audio samples.
+
+       The filter accepts the following options:
+
+       shift
+	   Specify frequency shift. Allowed range is -INT_MAX to INT_MAX.
+	   Default value is 0.0.
+
+       level
+	   Set output gain applied to final output. Allowed range is from 0.0
+	   to 1.0.  Default value is 1.0.
+
+       order
+	   Set filter order used for filtering. Allowed range is from 1 to 16.
+	   Default value is 8.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   afwtdn
+       Reduce broadband noise from input samples using Wavelets.
+
+       A description of the accepted options follows.
+
+       sigma
+	   Set the noise sigma, allowed range is from 0 to 1.  Default value
+	   is 0.  This option controls strength of denoising applied to input
+	   samples.  Most useful way to set this option is via decibels, eg.
+	   -45dB.
+
+       levels
+	   Set the number of wavelet levels of decomposition.  Allowed range
+	   is from 1 to 12.  Default value is 10.  Setting this too low make
+	   denoising performance very poor.
+
+       wavet
+	   Set wavelet type for decomposition of input frame.  They are sorted
+	   by number of coefficients, from lowest to highest.  More
+	   coefficients means worse filtering speed, but overall better
+	   quality.  Available wavelets are:
+
+	   sym2
+	   sym4
+	   rbior68
+	   deb10
+	   sym10
+	   coif5
+	   bl3
+       percent
+	   Set percent of full denoising. Allowed range is from 0 to 100
+	   percent.  Default value is 85 percent or partial denoising.
+
+       profile
+	   If enabled, first input frame will be used as noise profile.  If
+	   first frame samples contain non-noise performance will be very
+	   poor.
+
+       adaptive
+	   If enabled, input frames are analyzed for presence of noise.  If
+	   noise is detected with high possibility then input frame profile
+	   will be used for processing following frames, until new noise frame
+	   is detected.
+
+       samples
+	   Set size of single frame in number of samples. Allowed range is
+	   from 512 to 65536. Default frame size is 8192 samples.
+
+       softness
+	   Set softness applied inside thresholding function. Allowed range is
+	   from 0 to 10. Default softness is 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   agate
+       A gate is mainly used to reduce lower parts of a signal. This kind of
+       signal processing reduces disturbing noise between useful signals.
+
+       Gating is done by detecting the volume below a chosen level threshold
+       and dividing it by the factor set with ratio. The bottom of the noise
+       floor is set via range. Because an exact manipulation of the signal
+       would cause distortion of the waveform the reduction can be levelled
+       over time. This is done by setting attack and release.
+
+       attack determines how long the signal has to fall below the threshold
+       before any reduction will occur and release sets the time the signal
+       has to rise above the threshold to reduce the reduction again.  Shorter
+       signals than the chosen attack time will be left untouched.
+
+       level_in
+	   Set input level before filtering.  Default is 1. Allowed range is
+	   from 0.015625 to 64.
+
+       mode
+	   Set the mode of operation. Can be "upward" or "downward".  Default
+	   is "downward". If set to "upward" mode, higher parts of signal will
+	   be amplified, expanding dynamic range in upward direction.
+	   Otherwise, in case of "downward" lower parts of signal will be
+	   reduced.
+
+       range
+	   Set the level of gain reduction when the signal is below the
+	   threshold.  Default is 0.06125. Allowed range is from 0 to 1.
+	   Setting this to 0 disables reduction and then filter behaves like
+	   expander.
+
+       threshold
+	   If a signal rises above this level the gain reduction is released.
+	   Default is 0.125. Allowed range is from 0 to 1.
+
+       ratio
+	   Set a ratio by which the signal is reduced.	Default is 2. Allowed
+	   range is from 1 to 9000.
+
+       attack
+	   Amount of milliseconds the signal has to rise above the threshold
+	   before gain reduction stops.  Default is 20 milliseconds. Allowed
+	   range is from 0.01 to 9000.
+
+       release
+	   Amount of milliseconds the signal has to fall below the threshold
+	   before the reduction is increased again. Default is 250
+	   milliseconds.  Allowed range is from 0.01 to 9000.
+
+       makeup
+	   Set amount of amplification of signal after processing.  Default is
+	   1. Allowed range is from 1 to 64.
+
+       knee
+	   Curve the sharp knee around the threshold to enter gain reduction
+	   more softly.  Default is 2.828427125. Allowed range is from 1 to 8.
+
+       detection
+	   Choose if exact signal should be taken for detection or an RMS like
+	   one.  Default is "rms". Can be "peak" or "rms".
+
+       link
+	   Choose if the average level between all channels or the louder
+	   channel affects the reduction.  Default is "average". Can be
+	   "average" or "maximum".
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   aiir
+       Apply an arbitrary Infinite Impulse Response filter.
+
+       It accepts the following parameters:
+
+       zeros, z
+	   Set B/numerator/zeros/reflection coefficients.
+
+       poles, p
+	   Set A/denominator/poles/ladder coefficients.
+
+       gains, k
+	   Set channels gains.
+
+       dry_gain
+	   Set input gain.
+
+       wet_gain
+	   Set output gain.
+
+       format, f
+	   Set coefficients format.
+
+	   ll  lattice-ladder function
+
+	   sf  analog transfer function
+
+	   tf  digital transfer function
+
+	   zp  Z-plane zeros/poles, cartesian (default)
+
+	   pr  Z-plane zeros/poles, polar radians
+
+	   pd  Z-plane zeros/poles, polar degrees
+
+	   sp  S-plane zeros/poles
+
+       process, r
+	   Set type of processing.
+
+	   d   direct processing
+
+	   s   serial processing
+
+	   p   parallel processing
+
+       precision, e
+	   Set filtering precision.
+
+	   dbl double-precision floating-point (default)
+
+	   flt single-precision floating-point
+
+	   i32 32-bit integers
+
+	   i16 16-bit integers
+
+       normalize, n
+	   Normalize filter coefficients, by default is enabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       mix How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       response
+	   Show IR frequency response, magnitude(magenta), phase(green) and
+	   group delay(yellow) in additional video stream.  By default it is
+	   disabled.
+
+       channel
+	   Set for which IR channel to display frequency response. By default
+	   is first channel displayed. This option is used only when response
+	   is enabled.
+
+       size
+	   Set video stream size. This option is used only when response is
+	   enabled.
+
+       Coefficients in "tf" and "sf" format are separated by spaces and are in
+       ascending order.
+
+       Coefficients in "zp" format are separated by spaces and order of
+       coefficients doesn't matter. Coefficients in "zp" format are complex
+       numbers with i imaginary unit.
+
+       Different coefficients and gains can be provided for every channel, in
+       such case use '|' to separate coefficients or gains. Last provided
+       coefficients will be used for all remaining channels.
+
+       Examples
+
+       o   Apply 2 pole elliptic notch at around 5000Hz for 48000 Hz sample
+	   rate:
+
+		   aiir=k=1:z=7.957584807809675810E-1 -2.575128568908332300 3.674839853930788710 -2.57512875289799137 7.957586296317130880E-1:p=1 -2.86950072432325953 3.63022088054647218 -2.28075678147272232 6.361362326477423500E-1:f=tf:r=d
+
+       o   Same as above but in "zp" format:
+
+		   aiir=k=0.79575848078096756:z=0.80918701+0.58773007i 0.80918701-0.58773007i 0.80884700+0.58784055i 0.80884700-0.58784055i:p=0.63892345+0.59951235i 0.63892345-0.59951235i 0.79582691+0.44198673i 0.79582691-0.44198673i:f=zp:r=s
+
+       o   Apply 3-rd order analog normalized Butterworth low-pass filter,
+	   using analog transfer function format:
+
+		   aiir=z=1.3057 0 0 0:p=1.3057 2.3892 2.1860 1:f=sf:r=d
+
+   alimiter
+       The limiter prevents an input signal from rising over a desired
+       threshold.  This limiter uses lookahead technology to prevent your
+       signal from distorting.	It means that there is a small delay after the
+       signal is processed. Keep in mind that the delay it produces is the
+       attack time you set.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input gain. Default is 1.
+
+       level_out
+	   Set output gain. Default is 1.
+
+       limit
+	   Don't let signals above this level pass the limiter. Default is 1.
+
+       attack
+	   The limiter will reach its attenuation level in this amount of time
+	   in milliseconds. Default is 5 milliseconds.
+
+       release
+	   Come back from limiting to attenuation 1.0 in this amount of
+	   milliseconds.  Default is 50 milliseconds.
+
+       asc When gain reduction is always needed ASC takes care of releasing to
+	   an average reduction level rather than reaching a reduction of 0 in
+	   the release time.
+
+       asc_level
+	   Select how much the release time is affected by ASC, 0 means nearly
+	   no changes in release time while 1 produces higher release times.
+
+       level
+	   Auto level output signal. Default is enabled.  This normalizes
+	   audio back to 0dB if enabled.
+
+       latency
+	   Compensate the delay introduced by using the lookahead buffer set
+	   with attack parameter. Also flush the valid audio data in the
+	   lookahead buffer when the stream hits EOF.
+
+       Depending on picked setting it is recommended to upsample input 2x or
+       4x times with aresample before applying this filter.
+
+   allpass
+       Apply a two-pole all-pass filter with central frequency (in Hz)
+       frequency, and filter-width width.  An all-pass filter changes the
+       audio's frequency to phase relationship without changing its frequency
+       to amplitude relationship.
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set frequency in Hz.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Specify the band-width of a filter in width_type units.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       order, o
+	   Set the filter order, can be 1 or 2. Default is 2.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change allpass frequency.  Syntax for the command is : "frequency"
+
+       width_type, t
+	   Change allpass width_type.  Syntax for the command is :
+	   "width_type"
+
+       width, w
+	   Change allpass width.  Syntax for the command is : "width"
+
+       mix, m
+	   Change allpass mix.	Syntax for the command is : "mix"
+
+   aloop
+       Loop audio samples.
+
+       The filter accepts the following options:
+
+       loop
+	   Set the number of loops. Setting this value to -1 will result in
+	   infinite loops.  Default is 0.
+
+       size
+	   Set maximal number of samples. Default is 0.
+
+       start
+	   Set first sample of loop. Default is 0.
+
+   amerge
+       Merge two or more audio streams into a single multi-channel stream.
+
+       The filter accepts the following options:
+
+       inputs
+	   Set the number of inputs. Default is 2.
+
+       If the channel layouts of the inputs are disjoint, and therefore
+       compatible, the channel layout of the output will be set accordingly
+       and the channels will be reordered as necessary. If the channel layouts
+       of the inputs are not disjoint, the output will have all the channels
+       of the first input then all the channels of the second input, in that
+       order, and the channel layout of the output will be the default value
+       corresponding to the total number of channels.
+
+       For example, if the first input is in 2.1 (FL+FR+LF) and the second
+       input is FC+BL+BR, then the output will be in 5.1, with the channels in
+       the following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of
+       the first input, b1 is the first channel of the second input).
+
+       On the other hand, if both input are in stereo, the output channels
+       will be in the default order: a1, a2, b1, b2, and the channel layout
+       will be arbitrarily set to 4.0, which may or may not be the expected
+       value.
+
+       All inputs must have the same sample rate, and format.
+
+       If inputs do not have the same duration, the output will stop with the
+       shortest.
+
+       Examples
+
+       o   Merge two mono files into a stereo stream:
+
+		   amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
+
+       o   Multiple merges assuming 1 video stream and 6 audio streams in
+	   input.mkv:
+
+		   ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
+
+   amix
+       Mixes multiple audio inputs into a single output.
+
+       Note that this filter only supports float samples (the amerge and pan
+       audio filters support many formats). If the amix input has integer
+       samples then aresample will be automatically inserted to perform the
+       conversion to float samples.
+
+       It accepts the following parameters:
+
+       inputs
+	   The number of inputs. If unspecified, it defaults to 2.
+
+       duration
+	   How to determine the end-of-stream.
+
+	   longest
+	       The duration of the longest input. (default)
+
+	   shortest
+	       The duration of the shortest input.
+
+	   first
+	       The duration of the first input.
+
+       dropout_transition
+	   The transition time, in seconds, for volume renormalization when an
+	   input stream ends. The default value is 2 seconds.
+
+       weights
+	   Specify weight of each input audio stream as a sequence of numbers
+	   separated by a space. If fewer weights are specified compared to
+	   number of inputs, the last weight is assigned to the remaining
+	   inputs.  Default weight for each input is 1.
+
+       normalize
+	   Always scale inputs instead of only doing summation of samples.
+	   Beware of heavy clipping if inputs are not normalized prior or
+	   after filtering by this filter if this option is disabled. By
+	   default is enabled.
+
+       Examples
+
+       o   This will mix 3 input audio streams to a single output with the
+	   same duration as the first input and a dropout transition time of 3
+	   seconds:
+
+		   ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
+
+       o   This will mix one vocal and one music input audio stream to a
+	   single output with the same duration as the longest input. The
+	   music will have quarter the weight as the vocals, and the inputs
+	   are not normalized:
+
+		   ffmpeg -i VOCALS -i MUSIC -filter_complex amix=inputs=2:duration=longest:dropout_transition=0:weights="1 0.25":normalize=0 OUTPUT
+
+       Commands
+
+       This filter supports the following commands:
+
+       weights
+       normalize
+	   Syntax is same as option with same name.
+
+   amultiply
+       Multiply first audio stream with second audio stream and store result
+       in output audio stream. Multiplication is done by multiplying each
+       sample from first stream with sample at same position from second
+       stream.
+
+       With this element-wise multiplication one can create amplitude fades
+       and amplitude modulations.
+
+   anequalizer
+       High-order parametric multiband equalizer for each channel.
+
+       It accepts the following parameters:
+
+       params
+	   This option string is in format: "cchn f=cf w=w g=g t=f | ..."
+	   Each equalizer band is separated by '|'.
+
+	   chn Set channel number to which equalization will be applied.  If
+	       input doesn't have that channel the entry is ignored.
+
+	   f   Set central frequency for band.	If input doesn't have that
+	       frequency the entry is ignored.
+
+	   w   Set band width in Hertz.
+
+	   g   Set band gain in dB.
+
+	   t   Set filter type for band, optional, can be:
+
+	       0   Butterworth, this is default.
+
+	       1   Chebyshev type 1.
+
+	       2   Chebyshev type 2.
+
+       curves
+	   With this option activated frequency response of anequalizer is
+	   displayed in video stream.
+
+       size
+	   Set video stream size. Only useful if curves option is activated.
+
+       mgain
+	   Set max gain that will be displayed. Only useful if curves option
+	   is activated.  Setting this to a reasonable value makes it possible
+	   to display gain which is derived from neighbour bands which are too
+	   close to each other and thus produce higher gain when both are
+	   activated.
+
+       fscale
+	   Set frequency scale used to draw frequency response in video
+	   output.  Can be linear or logarithmic. Default is logarithmic.
+
+       colors
+	   Set color for each channel curve which is going to be displayed in
+	   video stream.  This is list of color names separated by space or by
+	   '|'.  Unrecognised or missing colors will be replaced by white
+	   color.
+
+       Examples
+
+       o   Lower gain by 10 of central frequency 200Hz and width 100 Hz for
+	   first 2 channels using Chebyshev type 1 filter:
+
+		   anequalizer=c0 f=200 w=100 g=-10 t=1|c1 f=200 w=100 g=-10 t=1
+
+       Commands
+
+       This filter supports the following commands:
+
+       change
+	   Alter existing filter parameters.  Syntax for the commands is :
+	   "fN|f=freq|w=width|g=gain"
+
+	   fN is existing filter number, starting from 0, if no such filter is
+	   available error is returned.  freq set new frequency parameter.
+	   width set new width parameter in Hertz.  gain set new gain
+	   parameter in dB.
+
+	   Full filter invocation with asendcmd may look like this:
+	   asendcmd=c='4.0 anequalizer change
+	   0|f=200|w=50|g=1',anequalizer=...
+
+   anlmdn
+       Reduce broadband noise in audio samples using Non-Local Means
+       algorithm.
+
+       Each sample is adjusted by looking for other samples with similar
+       contexts. This context similarity is defined by comparing their
+       surrounding patches of size p. Patches are searched in an area of r
+       around the sample.
+
+       The filter accepts the following options:
+
+       strength, s
+	   Set denoising strength. Allowed range is from 0.00001 to 10000.
+	   Default value is 0.00001.
+
+       patch, p
+	   Set patch radius duration. Allowed range is from 1 to 100
+	   milliseconds.  Default value is 2 milliseconds.
+
+       research, r
+	   Set research radius duration. Allowed range is from 2 to 300
+	   milliseconds.  Default value is 6 milliseconds.
+
+       output, o
+	   Set the output mode.
+
+	   It accepts the following values:
+
+	   i   Pass input unchanged.
+
+	   o   Pass noise filtered out.
+
+	   n   Pass only noise.
+
+	       Default value is o.
+
+       smooth, m
+	   Set smooth factor. Default value is 11. Allowed range is from 1 to
+	   1000.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   anlmf, anlms
+       Apply Normalized Least-Mean-(Squares|Fourth) algorithm to the first
+       audio stream using the second audio stream.
+
+       This adaptive filter is used to mimic a desired filter by finding the
+       filter coefficients that relate to producing the least mean square of
+       the error signal (difference between the desired, 2nd input audio
+       stream and the actual signal, the 1st input audio stream).
+
+       A description of the accepted options follows.
+
+       order
+	   Set filter order.
+
+       mu  Set filter mu.
+
+       eps Set the filter eps.
+
+       leakage
+	   Set the filter leakage.
+
+       out_mode
+	   It accepts the following values:
+
+	   i   Pass the 1st input.
+
+	   d   Pass the 2nd input.
+
+	   o   Pass filtered samples.
+
+	   n   Pass difference between desired and filtered samples.
+
+	       Default value is o.
+
+       Examples
+
+       o   One of many usages of this filter is noise reduction, input audio
+	   is filtered with same samples that are delayed by fixed amount, one
+	   such example for stereo audio is:
+
+		   asplit[a][b],[a]adelay=32S|32S[a],[b][a]anlms=order=128:leakage=0.0005:mu=.5:out_mode=o
+
+       Commands
+
+       This filter supports the same commands as options, excluding option
+       "order".
+
+   anull
+       Pass the audio source unchanged to the output.
+
+   apad
+       Pad the end of an audio stream with silence.
+
+       This can be used together with ffmpeg -shortest to extend audio streams
+       to the same length as the video stream.
+
+       A description of the accepted options follows.
+
+       packet_size
+	   Set silence packet size. Default value is 4096.
+
+       pad_len
+	   Set the number of samples of silence to add to the end. After the
+	   value is reached, the stream is terminated. This option is mutually
+	   exclusive with whole_len.
+
+       whole_len
+	   Set the minimum total number of samples in the output audio stream.
+	   If the value is longer than the input audio length, silence is
+	   added to the end, until the value is reached. This option is
+	   mutually exclusive with pad_len.
+
+       pad_dur
+	   Specify the duration of samples of silence to add. See the Time
+	   duration section in the ffmpeg-utils(1) manual for the accepted
+	   syntax. Used only if set to non-negative value.
+
+       whole_dur
+	   Specify the minimum total duration in the output audio stream. See
+	   the Time duration section in the ffmpeg-utils(1) manual for the
+	   accepted syntax. Used only if set to non-negative value. If the
+	   value is longer than the input audio length, silence is added to
+	   the end, until the value is reached.  This option is mutually
+	   exclusive with pad_dur
+
+       If neither the pad_len nor the whole_len nor pad_dur nor whole_dur
+       option is set, the filter will add silence to the end of the input
+       stream indefinitely.
+
+       Note that for ffmpeg 4.4 and earlier a zero pad_dur or whole_dur also
+       caused the filter to add silence indefinitely.
+
+       Examples
+
+       o   Add 1024 samples of silence to the end of the input:
+
+		   apad=pad_len=1024
+
+       o   Make sure the audio output will contain at least 10000 samples, pad
+	   the input with silence if required:
+
+		   apad=whole_len=10000
+
+       o   Use ffmpeg to pad the audio input with silence, so that the video
+	   stream will always result the shortest and will be converted until
+	   the end in the output file when using the shortest option:
+
+		   ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
+
+   aphaser
+       Add a phasing effect to the input audio.
+
+       A phaser filter creates series of peaks and troughs in the frequency
+       spectrum.  The position of the peaks and troughs are modulated so that
+       they vary over time, creating a sweeping effect.
+
+       A description of the accepted parameters follows.
+
+       in_gain
+	   Set input gain. Default is 0.4.
+
+       out_gain
+	   Set output gain. Default is 0.74
+
+       delay
+	   Set delay in milliseconds. Default is 3.0.
+
+       decay
+	   Set decay. Default is 0.4.
+
+       speed
+	   Set modulation speed in Hz. Default is 0.5.
+
+       type
+	   Set modulation type. Default is triangular.
+
+	   It accepts the following values:
+
+	   triangular, t
+	   sinusoidal, s
+
+   aphaseshift
+       Apply phase shift to input audio samples.
+
+       The filter accepts the following options:
+
+       shift
+	   Specify phase shift. Allowed range is from -1.0 to 1.0.  Default
+	   value is 0.0.
+
+       level
+	   Set output gain applied to final output. Allowed range is from 0.0
+	   to 1.0.  Default value is 1.0.
+
+       order
+	   Set filter order used for filtering. Allowed range is from 1 to 16.
+	   Default value is 8.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   apsyclip
+       Apply Psychoacoustic clipper to input audio stream.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input gain. By default it is 1. Range is [0.015625 - 64].
+
+       level_out
+	   Set output gain. By default it is 1. Range is [0.015625 - 64].
+
+       clip
+	   Set the clipping start value. Default value is 0dBFS or 1.
+
+       diff
+	   Output only difference samples, useful to hear introduced
+	   distortions.  By default is disabled.
+
+       adaptive
+	   Set strength of adaptive distortion applied. Default value is 0.5.
+	   Allowed range is from 0 to 1.
+
+       iterations
+	   Set number of iterations of psychoacoustic clipper.	Allowed range
+	   is from 1 to 20. Default value is 10.
+
+       level
+	   Auto level output signal. Default is disabled.  This normalizes
+	   audio back to 0dBFS if enabled.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   apulsator
+       Audio pulsator is something between an autopanner and a tremolo.  But
+       it can produce funny stereo effects as well. Pulsator changes the
+       volume of the left and right channel based on a LFO (low frequency
+       oscillator) with different waveforms and shifted phases.  This filter
+       have the ability to define an offset between left and right channel. An
+       offset of 0 means that both LFO shapes match each other.  The left and
+       right channel are altered equally - a conventional tremolo.  An offset
+       of 50% means that the shape of the right channel is exactly shifted in
+       phase (or moved backwards about half of the frequency) - pulsator acts
+       as an autopanner. At 1 both curves match again. Every setting in
+       between moves the phase shift gapless between all stages and produces
+       some "bypassing" sounds with sine and triangle waveforms. The more you
+       set the offset near 1 (starting from the 0.5) the faster the signal
+       passes from the left to the right speaker.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input gain. By default it is 1. Range is [0.015625 - 64].
+
+       level_out
+	   Set output gain. By default it is 1. Range is [0.015625 - 64].
+
+       mode
+	   Set waveform shape the LFO will use. Can be one of: sine, triangle,
+	   square, sawup or sawdown. Default is sine.
+
+       amount
+	   Set modulation. Define how much of original signal is affected by
+	   the LFO.
+
+       offset_l
+	   Set left channel offset. Default is 0. Allowed range is [0 - 1].
+
+       offset_r
+	   Set right channel offset. Default is 0.5. Allowed range is [0 - 1].
+
+       width
+	   Set pulse width. Default is 1. Allowed range is [0 - 2].
+
+       timing
+	   Set possible timing mode. Can be one of: bpm, ms or hz. Default is
+	   hz.
+
+       bpm Set bpm. Default is 120. Allowed range is [30 - 300]. Only used if
+	   timing is set to bpm.
+
+       ms  Set ms. Default is 500. Allowed range is [10 - 2000]. Only used if
+	   timing is set to ms.
+
+       hz  Set frequency in Hz. Default is 2. Allowed range is [0.01 - 100].
+	   Only used if timing is set to hz.
+
+   aresample
+       Resample the input audio to the specified parameters, using the
+       libswresample library. If none are specified then the filter will
+       automatically convert between its input and output.
+
+       This filter is also able to stretch/squeeze the audio data to make it
+       match the timestamps or to inject silence / cut out audio to make it
+       match the timestamps, do a combination of both or do neither.
+
+       The filter accepts the syntax [sample_rate:]resampler_options, where
+       sample_rate expresses a sample rate and resampler_options is a list of
+       key=value pairs, separated by ":". See the "Resampler Options" section
+       in the ffmpeg-resampler(1) manual for the complete list of supported
+       options.
+
+       Examples
+
+       o   Resample the input audio to 44100Hz:
+
+		   aresample=44100
+
+       o   Stretch/squeeze samples to the given timestamps, with a maximum of
+	   1000 samples per second compensation:
+
+		   aresample=async=1000
+
+   areverse
+       Reverse an audio clip.
+
+       Warning: This filter requires memory to buffer the entire clip, so
+       trimming is suggested.
+
+       Examples
+
+       o   Take the first 5 seconds of a clip, and reverse it.
+
+		   atrim=end=5,areverse
+
+   arnndn
+       Reduce noise from speech using Recurrent Neural Networks.
+
+       This filter accepts the following options:
+
+       model, m
+	   Set train model file to load. This option is always required.
+
+       mix Set how much to mix filtered samples into final output.  Allowed
+	   range is from -1 to 1. Default value is 1.  Negative values are
+	   special, they set how much to keep filtered noise in the final
+	   filter output. Set this option to -1 to hear actual noise removed
+	   from input signal.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   asdr
+       Measure Audio Signal-to-Distortion Ratio.
+
+       This filter takes two audio streams for input, and outputs first audio
+       stream.	Results are in dB per channel at end of either input.
+
+   asetnsamples
+       Set the number of samples per each output audio frame.
+
+       The last output packet may contain a different number of samples, as
+       the filter will flush all the remaining samples when the input audio
+       signals its end.
+
+       The filter accepts the following options:
+
+       nb_out_samples, n
+	   Set the number of frames per each output audio frame. The number is
+	   intended as the number of samples per each channel.	Default value
+	   is 1024.
+
+       pad, p
+	   If set to 1, the filter will pad the last audio frame with zeroes,
+	   so that the last frame will contain the same number of samples as
+	   the previous ones. Default value is 1.
+
+       For example, to set the number of per-frame samples to 1234 and disable
+       padding for the last frame, use:
+
+	       asetnsamples=n=1234:p=0
+
+   asetrate
+       Set the sample rate without altering the PCM data.  This will result in
+       a change of speed and pitch.
+
+       The filter accepts the following options:
+
+       sample_rate, r
+	   Set the output sample rate. Default is 44100 Hz.
+
+   ashowinfo
+       Show a line containing various information for each input audio frame.
+       The input audio is not modified.
+
+       The shown line contains a sequence of key/value pairs of the form
+       key:value.
+
+       The following values are shown in the output:
+
+       n   The (sequential) number of the input frame, starting from 0.
+
+       pts The presentation timestamp of the input frame, in time base units;
+	   the time base depends on the filter input pad, and is usually
+	   1/sample_rate.
+
+       pts_time
+	   The presentation timestamp of the input frame in seconds.
+
+       pos position of the frame in the input stream, -1 if this information
+	   in unavailable and/or meaningless (for example in case of synthetic
+	   audio)
+
+       fmt The sample format.
+
+       chlayout
+	   The channel layout.
+
+       rate
+	   The sample rate for the audio frame.
+
+       nb_samples
+	   The number of samples (per channel) in the frame.
+
+       checksum
+	   The Adler-32 checksum (printed in hexadecimal) of the audio data.
+	   For planar audio, the data is treated as if all the planes were
+	   concatenated.
+
+       plane_checksums
+	   A list of Adler-32 checksums for each data plane.
+
+   asoftclip
+       Apply audio soft clipping.
+
+       Soft clipping is a type of distortion effect where the amplitude of a
+       signal is saturated along a smooth curve, rather than the abrupt shape
+       of hard-clipping.
+
+       This filter accepts the following options:
+
+       type
+	   Set type of soft-clipping.
+
+	   It accepts the following values:
+
+	   hard
+	   tanh
+	   atan
+	   cubic
+	   exp
+	   alg
+	   quintic
+	   sin
+	   erf
+       threshold
+	   Set threshold from where to start clipping. Default value is 0dB or
+	   1.
+
+       output
+	   Set gain applied to output. Default value is 0dB or 1.
+
+       param
+	   Set additional parameter which controls sigmoid function.
+
+       oversample
+	   Set oversampling factor.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   aspectralstats
+       Display frequency domain statistical information about the audio
+       channels.  Statistics are calculated and stored as metadata for each
+       audio channel and for each audio frame.
+
+       It accepts the following option:
+
+       win_size
+	   Set the window length in samples. Default value is 2048.  Allowed
+	   range is from 32 to 65536.
+
+       win_func
+	   Set window function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hann, hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default is "hann".
+
+       overlap
+	   Set window overlap. Allowed range is from 0 to 1. Default value is
+	   0.5.
+
+       measure
+	   Select the parameters which are measured. The metadata keys can be
+	   used as flags, default is all which measures everything.  none
+	   disables all measurement.
+
+       A list of each metadata key follows:
+
+       mean
+       variance
+       centroid
+       spread
+       skewness
+       kurtosis
+       entropy
+       flatness
+       crest
+       flux
+       slope
+       decrease
+       rolloff
+
+   asr
+       Automatic Speech Recognition
+
+       This filter uses PocketSphinx for speech recognition. To enable
+       compilation of this filter, you need to configure FFmpeg with
+       "--enable-pocketsphinx".
+
+       It accepts the following options:
+
+       rate
+	   Set sampling rate of input audio. Defaults is 16000.  This need to
+	   match speech models, otherwise one will get poor results.
+
+       hmm Set dictionary containing acoustic model files.
+
+       dict
+	   Set pronunciation dictionary.
+
+       lm  Set language model file.
+
+       lmctl
+	   Set language model set.
+
+       lmname
+	   Set which language model to use.
+
+       logfn
+	   Set output for log messages.
+
+       The filter exports recognized speech as the frame metadata
+       "lavfi.asr.text".
+
+   astats
+       Display time domain statistical information about the audio channels.
+       Statistics are calculated and displayed for each audio channel and,
+       where applicable, an overall figure is also given.
+
+       It accepts the following option:
+
+       length
+	   Short window length in seconds, used for peak and trough RMS
+	   measurement.  Default is 0.05 (50 milliseconds). Allowed range is
+	   "[0 - 10]".
+
+       metadata
+	   Set metadata injection. All the metadata keys are prefixed with
+	   "lavfi.astats.X", where "X" is channel number starting from 1 or
+	   string "Overall". Default is disabled.
+
+	   Available keys for each channel are: Bit_depth Crest_factor
+	   DC_offset Dynamic_range Entropy Flat_factor Max_difference
+	   Max_level Mean_difference Min_difference Min_level Noise_floor
+	   Noise_floor_count Number_of_Infs Number_of_NaNs Number_of_denormals
+	   Peak_count Peak_level RMS_difference RMS_peak RMS_trough
+	   Zero_crossings Zero_crossings_rate
+
+	   and for "Overall": Bit_depth DC_offset Entropy Flat_factor
+	   Max_difference Max_level Mean_difference Min_difference Min_level
+	   Noise_floor Noise_floor_count Number_of_Infs Number_of_NaNs
+	   Number_of_denormals Number_of_samples Peak_count Peak_level
+	   RMS_difference RMS_level RMS_peak RMS_trough
+
+	   For example, a full key looks like "lavfi.astats.1.DC_offset" or
+	   "lavfi.astats.Overall.Peak_count".
+
+	   Read below for the description of the keys.
+
+       reset
+	   Set the number of frames over which cumulative stats are calculated
+	   before being reset. Default is disabled.
+
+       measure_perchannel
+	   Select the parameters which are measured per channel. The metadata
+	   keys can be used as flags, default is all which measures
+	   everything.	none disables all per channel measurement.
+
+       measure_overall
+	   Select the parameters which are measured overall. The metadata keys
+	   can be used as flags, default is all which measures everything.
+	   none disables all overall measurement.
+
+       A description of the measure keys follow:
+
+       none
+	   no measures
+
+       all all measures
+
+       Bit_depth
+	   overall bit depth of audio, i.e. number of bits used for each
+	   sample
+
+       Crest_factor
+	   standard ratio of peak to RMS level (note: not in dB)
+
+       DC_offset
+	   mean amplitude displacement from zero
+
+       Dynamic_range
+	   measured dynamic range of audio in dB
+
+       Entropy
+	   entropy measured across whole audio, entropy of value near 1.0 is
+	   typically measured for white noise
+
+       Flat_factor
+	   flatness (i.e. consecutive samples with the same value) of the
+	   signal at its peak levels (i.e. either Min_level or Max_level)
+
+       Max_difference
+	   maximal difference between two consecutive samples
+
+       Max_level
+	   maximal sample level
+
+       Mean_difference
+	   mean difference between two consecutive samples, i.e. the average
+	   of each difference between two consecutive samples
+
+       Min_difference
+	   minimal difference between two consecutive samples
+
+       Min_level
+	   minimal sample level
+
+       Noise_floor
+	   minimum local peak measured in dBFS over a short window
+
+       Noise_floor_count
+	   number of occasions (not the number of samples) that the signal
+	   attained Noise floor
+
+       Number_of_Infs
+	   number of samples with an infinite value
+
+       Number_of_NaNs
+	   number of samples with a NaN (not a number) value
+
+       Number_of_denormals
+	   number of samples with a subnormal value
+
+       Number_of_samples
+	   number of samples
+
+       Peak_count
+	   number of occasions (not the number of samples) that the signal
+	   attained either Min_level or Max_level
+
+       Peak_level
+	   standard peak level measured in dBFS
+
+       RMS_difference
+	   Root Mean Square difference between two consecutive samples
+
+       RMS_level
+	   standard RMS level measured in dBFS
+
+       RMS_peak
+       RMS_trough
+	   peak and trough values for RMS level measured over a short window,
+	   measured in dBFS.
+
+       Zero crossings
+	   number of points where the waveform crosses the zero level axis
+
+       Zero crossings rate
+	   rate of Zero crossings and number of audio samples
+
+   asubboost
+       Boost subwoofer frequencies.
+
+       The filter accepts the following options:
+
+       dry Set dry gain, how much of original signal is kept. Allowed range is
+	   from 0 to 1.  Default value is 1.0.
+
+       wet Set wet gain, how much of filtered signal is kept. Allowed range is
+	   from 0 to 1.  Default value is 1.0.
+
+       boost
+	   Set max boost factor. Allowed range is from 1 to 12. Default value
+	   is 2.
+
+       decay
+	   Set delay line decay gain value. Allowed range is from 0 to 1.
+	   Default value is 0.0.
+
+       feedback
+	   Set delay line feedback gain value. Allowed range is from 0 to 1.
+	   Default value is 0.9.
+
+       cutoff
+	   Set cutoff frequency in Hertz. Allowed range is 50 to 900.  Default
+	   value is 100.
+
+       slope
+	   Set slope amount for cutoff frequency. Allowed range is 0.0001 to
+	   1.  Default value is 0.5.
+
+       delay
+	   Set delay. Allowed range is from 1 to 100.  Default value is 20.
+
+       channels
+	   Set the channels to process. Default value is all available.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   asubcut
+       Cut subwoofer frequencies.
+
+       This filter allows to set custom, steeper roll off than highpass
+       filter, and thus is able to more attenuate frequency content in stop-
+       band.
+
+       The filter accepts the following options:
+
+       cutoff
+	   Set cutoff frequency in Hertz. Allowed range is 2 to 200.  Default
+	   value is 20.
+
+       order
+	   Set filter order. Available values are from 3 to 20.  Default value
+	   is 10.
+
+       level
+	   Set input gain level. Allowed range is from 0 to 1. Default value
+	   is 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   asupercut
+       Cut super frequencies.
+
+       The filter accepts the following options:
+
+       cutoff
+	   Set cutoff frequency in Hertz. Allowed range is 20000 to 192000.
+	   Default value is 20000.
+
+       order
+	   Set filter order. Available values are from 3 to 20.  Default value
+	   is 10.
+
+       level
+	   Set input gain level. Allowed range is from 0 to 1. Default value
+	   is 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   asuperpass
+       Apply high order Butterworth band-pass filter.
+
+       The filter accepts the following options:
+
+       centerf
+	   Set center frequency in Hertz. Allowed range is 2 to 999999.
+	   Default value is 1000.
+
+       order
+	   Set filter order. Available values are from 4 to 20.  Default value
+	   is 4.
+
+       qfactor
+	   Set Q-factor. Allowed range is from 0.01 to 100. Default value is
+	   1.
+
+       level
+	   Set input gain level. Allowed range is from 0 to 2. Default value
+	   is 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   asuperstop
+       Apply high order Butterworth band-stop filter.
+
+       The filter accepts the following options:
+
+       centerf
+	   Set center frequency in Hertz. Allowed range is 2 to 999999.
+	   Default value is 1000.
+
+       order
+	   Set filter order. Available values are from 4 to 20.  Default value
+	   is 4.
+
+       qfactor
+	   Set Q-factor. Allowed range is from 0.01 to 100. Default value is
+	   1.
+
+       level
+	   Set input gain level. Allowed range is from 0 to 2. Default value
+	   is 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   atempo
+       Adjust audio tempo.
+
+       The filter accepts exactly one parameter, the audio tempo. If not
+       specified then the filter will assume nominal 1.0 tempo. Tempo must be
+       in the [0.5, 100.0] range.
+
+       Note that tempo greater than 2 will skip some samples rather than blend
+       them in.  If for any reason this is a concern it is always possible to
+       daisy-chain several instances of atempo to achieve the desired product
+       tempo.
+
+       Examples
+
+       o   Slow down audio to 80% tempo:
+
+		   atempo=0.8
+
+       o   To speed up audio to 300% tempo:
+
+		   atempo=3
+
+       o   To speed up audio to 300% tempo by daisy-chaining two atempo
+	   instances:
+
+		   atempo=sqrt(3),atempo=sqrt(3)
+
+       Commands
+
+       This filter supports the following commands:
+
+       tempo
+	   Change filter tempo scale factor.  Syntax for the command is :
+	   "tempo"
+
+   atilt
+       Apply spectral tilt filter to audio stream.
+
+       This filter apply any spectral roll-off slope over any specified
+       frequency band.
+
+       The filter accepts the following options:
+
+       freq
+	   Set central frequency of tilt in Hz. Default is 10000 Hz.
+
+       slope
+	   Set slope direction of tilt. Default is 0. Allowed range is from -1
+	   to 1.
+
+       width
+	   Set width of tilt. Default is 1000. Allowed range is from 100 to
+	   10000.
+
+       order
+	   Set order of tilt filter.
+
+       level
+	   Set input volume level. Allowed range is from 0 to 4.  Defalt is 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   atrim
+       Trim the input so that the output contains one continuous subpart of
+       the input.
+
+       It accepts the following parameters:
+
+       start
+	   Timestamp (in seconds) of the start of the section to keep. I.e.
+	   the audio sample with the timestamp start will be the first sample
+	   in the output.
+
+       end Specify time of the first audio sample that will be dropped, i.e.
+	   the audio sample immediately preceding the one with the timestamp
+	   end will be the last sample in the output.
+
+       start_pts
+	   Same as start, except this option sets the start timestamp in
+	   samples instead of seconds.
+
+       end_pts
+	   Same as end, except this option sets the end timestamp in samples
+	   instead of seconds.
+
+       duration
+	   The maximum duration of the output in seconds.
+
+       start_sample
+	   The number of the first sample that should be output.
+
+       end_sample
+	   The number of the first sample that should be dropped.
+
+       start, end, and duration are expressed as time duration specifications;
+       see the Time duration section in the ffmpeg-utils(1) manual.
+
+       Note that the first two sets of the start/end options and the duration
+       option look at the frame timestamp, while the _sample options simply
+       count the samples that pass through the filter. So start/end_pts and
+       start/end_sample will give different results when the timestamps are
+       wrong, inexact or do not start at zero. Also note that this filter does
+       not modify the timestamps. If you wish to have the output timestamps
+       start at zero, insert the asetpts filter after the atrim filter.
+
+       If multiple start or end options are set, this filter tries to be
+       greedy and keep all samples that match at least one of the specified
+       constraints. To keep only the part that matches all the constraints at
+       once, chain multiple atrim filters.
+
+       The defaults are such that all the input is kept. So it is possible to
+       set e.g.  just the end values to keep everything before the specified
+       time.
+
+       Examples:
+
+       o   Drop everything except the second minute of input:
+
+		   ffmpeg -i INPUT -af atrim=60:120
+
+       o   Keep only the first 1000 samples:
+
+		   ffmpeg -i INPUT -af atrim=end_sample=1000
+
+   axcorrelate
+       Calculate normalized windowed cross-correlation between two input audio
+       streams.
+
+       Resulted samples are always between -1 and 1 inclusive.	If result is 1
+       it means two input samples are highly correlated in that selected
+       segment.  Result 0 means they are not correlated at all.  If result is
+       -1 it means two input samples are out of phase, which means they cancel
+       each other.
+
+       The filter accepts the following options:
+
+       size
+	   Set size of segment over which cross-correlation is calculated.
+	   Default is 256. Allowed range is from 2 to 131072.
+
+       algo
+	   Set algorithm for cross-correlation. Can be "slow" or "fast".
+	   Default is "slow". Fast algorithm assumes mean values over any
+	   given segment are always zero and thus need much less calculations
+	   to make.  This is generally not true, but is valid for typical
+	   audio streams.
+
+       Examples
+
+       o   Calculate correlation between channels in stereo audio stream:
+
+		   ffmpeg -i stereo.wav -af channelsplit,axcorrelate=size=1024:algo=fast correlation.wav
+
+   bandpass
+       Apply a two-pole Butterworth band-pass filter with central frequency
+       frequency, and (3dB-point) band-width width.  The csg option selects a
+       constant skirt gain (peak gain = Q) instead of the default: constant
+       0dB peak gain.  The filter roll off at 6dB per octave (20dB per
+       decade).
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set the filter's central frequency. Default is 3000.
+
+       csg Constant skirt gain if set to 1. Defaults to 0.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Specify the band-width of a filter in width_type units.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change bandpass frequency.  Syntax for the command is : "frequency"
+
+       width_type, t
+	   Change bandpass width_type.	Syntax for the command is :
+	   "width_type"
+
+       width, w
+	   Change bandpass width.  Syntax for the command is : "width"
+
+       mix, m
+	   Change bandpass mix.  Syntax for the command is : "mix"
+
+   bandreject
+       Apply a two-pole Butterworth band-reject filter with central frequency
+       frequency, and (3dB-point) band-width width.  The filter roll off at
+       6dB per octave (20dB per decade).
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set the filter's central frequency. Default is 3000.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Specify the band-width of a filter in width_type units.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change bandreject frequency.  Syntax for the command is :
+	   "frequency"
+
+       width_type, t
+	   Change bandreject width_type.  Syntax for the command is :
+	   "width_type"
+
+       width, w
+	   Change bandreject width.  Syntax for the command is : "width"
+
+       mix, m
+	   Change bandreject mix.  Syntax for the command is : "mix"
+
+   bass, lowshelf
+       Boost or cut the bass (lower) frequencies of the audio using a two-pole
+       shelving filter with a response similar to that of a standard hi-fi's
+       tone-controls. This is also known as shelving equalisation (EQ).
+
+       The filter accepts the following options:
+
+       gain, g
+	   Give the gain at 0 Hz. Its useful range is about -20 (for a large
+	   cut) to +20 (for a large boost).  Beware of clipping when using a
+	   positive gain.
+
+       frequency, f
+	   Set the filter's central frequency and so can be used to extend or
+	   reduce the frequency range to be boosted or cut.  The default value
+	   is 100 Hz.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Determine how steep is the filter's shelf transition.
+
+       poles, p
+	   Set number of poles. Default is 2.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change bass frequency.  Syntax for the command is : "frequency"
+
+       width_type, t
+	   Change bass width_type.  Syntax for the command is : "width_type"
+
+       width, w
+	   Change bass width.  Syntax for the command is : "width"
+
+       gain, g
+	   Change bass gain.  Syntax for the command is : "gain"
+
+       mix, m
+	   Change bass mix.  Syntax for the command is : "mix"
+
+   biquad
+       Apply a biquad IIR filter with the given coefficients.  Where b0, b1,
+       b2 and a0, a1, a2 are the numerator and denominator coefficients
+       respectively.  and channels, c specify which channels to filter, by
+       default all available are filtered.
+
+       Commands
+
+       This filter supports the following commands:
+
+       a0
+       a1
+       a2
+       b0
+       b1
+       b2  Change biquad parameter.  Syntax for the command is : "value"
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+   bs2b
+       Bauer stereo to binaural transformation, which improves headphone
+       listening of stereo audio records.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-libbs2b".
+
+       It accepts the following parameters:
+
+       profile
+	   Pre-defined crossfeed level.
+
+	   default
+	       Default level (fcut=700, feed=50).
+
+	   cmoy
+	       Chu Moy circuit (fcut=700, feed=60).
+
+	   jmeier
+	       Jan Meier circuit (fcut=650, feed=95).
+
+       fcut
+	   Cut frequency (in Hz).
+
+       feed
+	   Feed level (in Hz).
+
+   channelmap
+       Remap input channels to new locations.
+
+       It accepts the following parameters:
+
+       map Map channels from input to output. The argument is a '|'-separated
+	   list of mappings, each in the "in_channel-out_channel" or
+	   in_channel form. in_channel can be either the name of the input
+	   channel (e.g. FL for front left) or its index in the input channel
+	   layout.  out_channel is the name of the output channel or its index
+	   in the output channel layout. If out_channel is not given then it
+	   is implicitly an index, starting with zero and increasing by one
+	   for each mapping.
+
+       channel_layout
+	   The channel layout of the output stream.
+
+       If no mapping is present, the filter will implicitly map input channels
+       to output channels, preserving indices.
+
+       Examples
+
+       o   For example, assuming a 5.1+downmix input MOV file,
+
+		   ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
+
+	   will create an output WAV file tagged as stereo from the downmix
+	   channels of the input.
+
+       o   To fix a 5.1 WAV improperly encoded in AAC's native channel order
+
+		   ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:5.1' out.wav
+
+   channelsplit
+       Split each channel from an input audio stream into a separate output
+       stream.
+
+       It accepts the following parameters:
+
+       channel_layout
+	   The channel layout of the input stream. The default is "stereo".
+
+       channels
+	   A channel layout describing the channels to be extracted as
+	   separate output streams or "all" to extract each input channel as a
+	   separate stream. The default is "all".
+
+	   Choosing channels not present in channel layout in the input will
+	   result in an error.
+
+       Examples
+
+       o   For example, assuming a stereo input MP3 file,
+
+		   ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
+
+	   will create an output Matroska file with two audio streams, one
+	   containing only the left channel and the other the right channel.
+
+       o   Split a 5.1 WAV file into per-channel files:
+
+		   ffmpeg -i in.wav -filter_complex
+		   'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
+		   -map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
+		   front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
+		   side_right.wav
+
+       o   Extract only LFE from a 5.1 WAV file:
+
+		   ffmpeg -i in.wav -filter_complex 'channelsplit=channel_layout=5.1:channels=LFE[LFE]'
+		   -map '[LFE]' lfe.wav
+
+   chorus
+       Add a chorus effect to the audio.
+
+       Can make a single vocal sound like a chorus, but can also be applied to
+       instrumentation.
+
+       Chorus resembles an echo effect with a short delay, but whereas with
+       echo the delay is constant, with chorus, it is varied using using
+       sinusoidal or triangular modulation.  The modulation depth defines the
+       range the modulated delay is played before or after the delay. Hence
+       the delayed sound will sound slower or faster, that is the delayed
+       sound tuned around the original one, like in a chorus where some vocals
+       are slightly off key.
+
+       It accepts the following parameters:
+
+       in_gain
+	   Set input gain. Default is 0.4.
+
+       out_gain
+	   Set output gain. Default is 0.4.
+
+       delays
+	   Set delays. A typical delay is around 40ms to 60ms.
+
+       decays
+	   Set decays.
+
+       speeds
+	   Set speeds.
+
+       depths
+	   Set depths.
+
+       Examples
+
+       o   A single delay:
+
+		   chorus=0.7:0.9:55:0.4:0.25:2
+
+       o   Two delays:
+
+		   chorus=0.6:0.9:50|60:0.4|0.32:0.25|0.4:2|1.3
+
+       o   Fuller sounding chorus with three delays:
+
+		   chorus=0.5:0.9:50|60|40:0.4|0.32|0.3:0.25|0.4|0.3:2|2.3|1.3
+
+   compand
+       Compress or expand the audio's dynamic range.
+
+       It accepts the following parameters:
+
+       attacks
+       decays
+	   A list of times in seconds for each channel over which the
+	   instantaneous level of the input signal is averaged to determine
+	   its volume. attacks refers to increase of volume and decays refers
+	   to decrease of volume. For most situations, the attack time
+	   (response to the audio getting louder) should be shorter than the
+	   decay time, because the human ear is more sensitive to sudden loud
+	   audio than sudden soft audio. A typical value for attack is 0.3
+	   seconds and a typical value for decay is 0.8 seconds.  If specified
+	   number of attacks & decays is lower than number of channels, the
+	   last set attack/decay will be used for all remaining channels.
+
+       points
+	   A list of points for the transfer function, specified in dB
+	   relative to the maximum possible signal amplitude. Each key points
+	   list must be defined using the following syntax:
+	   "x0/y0|x1/y1|x2/y2|...." or "x0/y0 x1/y1 x2/y2 ...."
+
+	   The input values must be in strictly increasing order but the
+	   transfer function does not have to be monotonically rising. The
+	   point "0/0" is assumed but may be overridden (by "0/out-dBn").
+	   Typical values for the transfer function are "-70/-70|-60/-20|1/0".
+
+       soft-knee
+	   Set the curve radius in dB for all joints. It defaults to 0.01.
+
+       gain
+	   Set the additional gain in dB to be applied at all points on the
+	   transfer function. This allows for easy adjustment of the overall
+	   gain.  It defaults to 0.
+
+       volume
+	   Set an initial volume, in dB, to be assumed for each channel when
+	   filtering starts. This permits the user to supply a nominal level
+	   initially, so that, for example, a very large gain is not applied
+	   to initial signal levels before the companding has begun to
+	   operate. A typical value for audio which is initially quiet is -90
+	   dB. It defaults to 0.
+
+       delay
+	   Set a delay, in seconds. The input audio is analyzed immediately,
+	   but audio is delayed before being fed to the volume adjuster.
+	   Specifying a delay approximately equal to the attack/decay times
+	   allows the filter to effectively operate in predictive rather than
+	   reactive mode. It defaults to 0.
+
+       Examples
+
+       o   Make music with both quiet and loud passages suitable for listening
+	   to in a noisy environment:
+
+		   compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
+
+	   Another example for audio with whisper and explosion parts:
+
+		   compand=0|0:1|1:-90/-900|-70/-70|-30/-9|0/-3:6:0:0:0
+
+       o   A noise gate for when the noise is at a lower level than the
+	   signal:
+
+		   compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
+
+       o   Here is another noise gate, this time for when the noise is at a
+	   higher level than the signal (making it, in some ways, similar to
+	   squelch):
+
+		   compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
+
+       o   2:1 compression starting at -6dB:
+
+		   compand=points=-80/-80|-6/-6|0/-3.8|20/3.5
+
+       o   2:1 compression starting at -9dB:
+
+		   compand=points=-80/-80|-9/-9|0/-5.3|20/2.9
+
+       o   2:1 compression starting at -12dB:
+
+		   compand=points=-80/-80|-12/-12|0/-6.8|20/1.9
+
+       o   2:1 compression starting at -18dB:
+
+		   compand=points=-80/-80|-18/-18|0/-9.8|20/0.7
+
+       o   3:1 compression starting at -15dB:
+
+		   compand=points=-80/-80|-15/-15|0/-10.8|20/-5.2
+
+       o   Compressor/Gate:
+
+		   compand=points=-80/-105|-62/-80|-15.4/-15.4|0/-12|20/-7.6
+
+       o   Expander:
+
+		   compand=attacks=0:points=-80/-169|-54/-80|-49.5/-64.6|-41.1/-41.1|-25.8/-15|-10.8/-4.5|0/0|20/8.3
+
+       o   Hard limiter at -6dB:
+
+		   compand=attacks=0:points=-80/-80|-6/-6|20/-6
+
+       o   Hard limiter at -12dB:
+
+		   compand=attacks=0:points=-80/-80|-12/-12|20/-12
+
+       o   Hard noise gate at -35 dB:
+
+		   compand=attacks=0:points=-80/-115|-35.1/-80|-35/-35|20/20
+
+       o   Soft limiter:
+
+		   compand=attacks=0:points=-80/-80|-12.4/-12.4|-6/-8|0/-6.8|20/-2.8
+
+   compensationdelay
+       Compensation Delay Line is a metric based delay to compensate differing
+       positions of microphones or speakers.
+
+       For example, you have recorded guitar with two microphones placed in
+       different locations. Because the front of sound wave has fixed speed in
+       normal conditions, the phasing of microphones can vary and depends on
+       their location and interposition. The best sound mix can be achieved
+       when these microphones are in phase (synchronized). Note that a
+       distance of ~30 cm between microphones makes one microphone capture the
+       signal in antiphase to the other microphone. That makes the final mix
+       sound moody.  This filter helps to solve phasing problems by adding
+       different delays to each microphone track and make them synchronized.
+
+       The best result can be reached when you take one track as base and
+       synchronize other tracks one by one with it.  Remember that
+       synchronization/delay tolerance depends on sample rate, too.  Higher
+       sample rates will give more tolerance.
+
+       The filter accepts the following parameters:
+
+       mm  Set millimeters distance. This is compensation distance for fine
+	   tuning.  Default is 0.
+
+       cm  Set cm distance. This is compensation distance for tightening
+	   distance setup.  Default is 0.
+
+       m   Set meters distance. This is compensation distance for hard
+	   distance setup.  Default is 0.
+
+       dry Set dry amount. Amount of unprocessed (dry) signal.	Default is 0.
+
+       wet Set wet amount. Amount of processed (wet) signal.  Default is 1.
+
+       temp
+	   Set temperature in degrees Celsius. This is the temperature of the
+	   environment.  Default is 20.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   crossfeed
+       Apply headphone crossfeed filter.
+
+       Crossfeed is the process of blending the left and right channels of
+       stereo audio recording.	It is mainly used to reduce extreme stereo
+       separation of low frequencies.
+
+       The intent is to produce more speaker like sound to the listener.
+
+       The filter accepts the following options:
+
+       strength
+	   Set strength of crossfeed. Default is 0.2. Allowed range is from 0
+	   to 1.  This sets gain of low shelf filter for side part of stereo
+	   image.  Default is -6dB. Max allowed is -30db when strength is set
+	   to 1.
+
+       range
+	   Set soundstage wideness. Default is 0.5. Allowed range is from 0 to
+	   1.  This sets cut off frequency of low shelf filter. Default is cut
+	   off near 1550 Hz. With range set to 1 cut off frequency is set to
+	   2100 Hz.
+
+       slope
+	   Set curve slope of low shelf filter. Default is 0.5.  Allowed range
+	   is from 0.01 to 1.
+
+       level_in
+	   Set input gain. Default is 0.9.
+
+       level_out
+	   Set output gain. Default is 1.
+
+       block_size
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   crystalizer
+       Simple algorithm for audio noise sharpening.
+
+       This filter linearly increases differences betweeen each audio sample.
+
+       The filter accepts the following options:
+
+       i   Sets the intensity of effect (default: 2.0). Must be in range
+	   between -10.0 to 0 (unchanged sound) to 10.0 (maximum effect).  To
+	   inverse filtering use negative value.
+
+       c   Enable clipping. By default is enabled.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   dcshift
+       Apply a DC shift to the audio.
+
+       This can be useful to remove a DC offset (caused perhaps by a hardware
+       problem in the recording chain) from the audio. The effect of a DC
+       offset is reduced headroom and hence volume. The astats filter can be
+       used to determine if a signal has a DC offset.
+
+       shift
+	   Set the DC shift, allowed range is [-1, 1]. It indicates the amount
+	   to shift the audio.
+
+       limitergain
+	   Optional. It should have a value much less than 1 (e.g. 0.05 or
+	   0.02) and is used to prevent clipping.
+
+   deesser
+       Apply de-essing to the audio samples.
+
+       i   Set intensity for triggering de-essing. Allowed range is from 0 to
+	   1.  Default is 0.
+
+       m   Set amount of ducking on treble part of sound. Allowed range is
+	   from 0 to 1.  Default is 0.5.
+
+       f   How much of original frequency content to keep when de-essing.
+	   Allowed range is from 0 to 1.  Default is 0.5.
+
+       s   Set the output mode.
+
+	   It accepts the following values:
+
+	   i   Pass input unchanged.
+
+	   o   Pass ess filtered out.
+
+	   e   Pass only ess.
+
+	       Default value is o.
+
+   dialoguenhance
+       Enhance dialogue in stereo audio.
+
+       This filter accepts stereo input and produce surround (3.0) channels
+       output.	The newly produced front center channel have enhanced speech
+       dialogue originally available in both stereo channels.  This filter
+       outputs front left and front right channels same as available in stereo
+       input.
+
+       The filter accepts the following options:
+
+       original
+	   Set the original center factor to keep in front center channel
+	   output.  Allowed range is from 0 to 1. Default value is 1.
+
+       enhance
+	   Set the dialogue enhance factor to put in front center channel
+	   output.  Allowed range is from 0 to 3. Default value is 1.
+
+       voice
+	   Set the voice detection factor.  Allowed range is from 2 to 32.
+	   Default value is 2.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   drmeter
+       Measure audio dynamic range.
+
+       DR values of 14 and higher is found in very dynamic material. DR of 8
+       to 13 is found in transition material. And anything less that 8 have
+       very poor dynamics and is very compressed.
+
+       The filter accepts the following options:
+
+       length
+	   Set window length in seconds used to split audio into segments of
+	   equal length.  Default is 3 seconds.
+
+   dynaudnorm
+       Dynamic Audio Normalizer.
+
+       This filter applies a certain amount of gain to the input audio in
+       order to bring its peak magnitude to a target level (e.g. 0 dBFS).
+       However, in contrast to more "simple" normalization algorithms, the
+       Dynamic Audio Normalizer *dynamically* re-adjusts the gain factor to
+       the input audio.  This allows for applying extra gain to the "quiet"
+       sections of the audio while avoiding distortions or clipping the "loud"
+       sections. In other words: The Dynamic Audio Normalizer will "even out"
+       the volume of quiet and loud sections, in the sense that the volume of
+       each section is brought to the same target level. Note, however, that
+       the Dynamic Audio Normalizer achieves this goal *without* applying
+       "dynamic range compressing". It will retain 100% of the dynamic range
+       *within* each section of the audio file.
+
+       framelen, f
+	   Set the frame length in milliseconds. In range from 10 to 8000
+	   milliseconds.  Default is 500 milliseconds.	The Dynamic Audio
+	   Normalizer processes the input audio in small chunks, referred to
+	   as frames. This is required, because a peak magnitude has no
+	   meaning for just a single sample value. Instead, we need to
+	   determine the peak magnitude for a contiguous sequence of sample
+	   values. While a "standard" normalizer would simply use the peak
+	   magnitude of the complete file, the Dynamic Audio Normalizer
+	   determines the peak magnitude individually for each frame. The
+	   length of a frame is specified in milliseconds. By default, the
+	   Dynamic Audio Normalizer uses a frame length of 500 milliseconds,
+	   which has been found to give good results with most files.  Note
+	   that the exact frame length, in number of samples, will be
+	   determined automatically, based on the sampling rate of the
+	   individual input audio file.
+
+       gausssize, g
+	   Set the Gaussian filter window size. In range from 3 to 301, must
+	   be odd number. Default is 31.  Probably the most important
+	   parameter of the Dynamic Audio Normalizer is the "window size" of
+	   the Gaussian smoothing filter. The filter's window size is
+	   specified in frames, centered around the current frame. For the
+	   sake of simplicity, this must be an odd number. Consequently, the
+	   default value of 31 takes into account the current frame, as well
+	   as the 15 preceding frames and the 15 subsequent frames. Using a
+	   larger window results in a stronger smoothing effect and thus in
+	   less gain variation, i.e. slower gain adaptation. Conversely, using
+	   a smaller window results in a weaker smoothing effect and thus in
+	   more gain variation, i.e. faster gain adaptation.  In other words,
+	   the more you increase this value, the more the Dynamic Audio
+	   Normalizer will behave like a "traditional" normalization filter.
+	   On the contrary, the more you decrease this value, the more the
+	   Dynamic Audio Normalizer will behave like a dynamic range
+	   compressor.
+
+       peak, p
+	   Set the target peak value. This specifies the highest permissible
+	   magnitude level for the normalized audio input. This filter will
+	   try to approach the target peak magnitude as closely as possible,
+	   but at the same time it also makes sure that the normalized signal
+	   will never exceed the peak magnitude.  A frame's maximum local gain
+	   factor is imposed directly by the target peak magnitude. The
+	   default value is 0.95 and thus leaves a headroom of 5%*.  It is not
+	   recommended to go above this value.
+
+       maxgain, m
+	   Set the maximum gain factor. In range from 1.0 to 100.0. Default is
+	   10.0.  The Dynamic Audio Normalizer determines the maximum possible
+	   (local) gain factor for each input frame, i.e. the maximum gain
+	   factor that does not result in clipping or distortion. The maximum
+	   gain factor is determined by the frame's highest magnitude sample.
+	   However, the Dynamic Audio Normalizer additionally bounds the
+	   frame's maximum gain factor by a predetermined (global) maximum
+	   gain factor. This is done in order to avoid excessive gain factors
+	   in "silent" or almost silent frames. By default, the maximum gain
+	   factor is 10.0, For most inputs the default value should be
+	   sufficient and it usually is not recommended to increase this
+	   value. Though, for input with an extremely low overall volume
+	   level, it may be necessary to allow even higher gain factors. Note,
+	   however, that the Dynamic Audio Normalizer does not simply apply a
+	   "hard" threshold (i.e. cut off values above the threshold).
+	   Instead, a "sigmoid" threshold function will be applied. This way,
+	   the gain factors will smoothly approach the threshold value, but
+	   never exceed that value.
+
+       targetrms, r
+	   Set the target RMS. In range from 0.0 to 1.0. Default is 0.0 -
+	   disabled.  By default, the Dynamic Audio Normalizer performs "peak"
+	   normalization.  This means that the maximum local gain factor for
+	   each frame is defined (only) by the frame's highest magnitude
+	   sample. This way, the samples can be amplified as much as possible
+	   without exceeding the maximum signal level, i.e. without clipping.
+	   Optionally, however, the Dynamic Audio Normalizer can also take
+	   into account the frame's root mean square, abbreviated RMS. In
+	   electrical engineering, the RMS is commonly used to determine the
+	   power of a time-varying signal. It is therefore considered that the
+	   RMS is a better approximation of the "perceived loudness" than just
+	   looking at the signal's peak magnitude. Consequently, by adjusting
+	   all frames to a constant RMS value, a uniform "perceived loudness"
+	   can be established. If a target RMS value has been specified, a
+	   frame's local gain factor is defined as the factor that would
+	   result in exactly that RMS value.  Note, however, that the maximum
+	   local gain factor is still restricted by the frame's highest
+	   magnitude sample, in order to prevent clipping.
+
+       coupling, n
+	   Enable channels coupling. By default is enabled.  By default, the
+	   Dynamic Audio Normalizer will amplify all channels by the same
+	   amount. This means the same gain factor will be applied to all
+	   channels, i.e.  the maximum possible gain factor is determined by
+	   the "loudest" channel.  However, in some recordings, it may happen
+	   that the volume of the different channels is uneven, e.g. one
+	   channel may be "quieter" than the other one(s).  In this case, this
+	   option can be used to disable the channel coupling. This way, the
+	   gain factor will be determined independently for each channel,
+	   depending only on the individual channel's highest magnitude
+	   sample. This allows for harmonizing the volume of the different
+	   channels.
+
+       correctdc, c
+	   Enable DC bias correction. By default is disabled.  An audio signal
+	   (in the time domain) is a sequence of sample values.  In the
+	   Dynamic Audio Normalizer these sample values are represented in the
+	   -1.0 to 1.0 range, regardless of the original input format.
+	   Normally, the audio signal, or "waveform", should be centered
+	   around the zero point.  That means if we calculate the mean value
+	   of all samples in a file, or in a single frame, then the result
+	   should be 0.0 or at least very close to that value. If, however,
+	   there is a significant deviation of the mean value from 0.0, in
+	   either positive or negative direction, this is referred to as a DC
+	   bias or DC offset. Since a DC bias is clearly undesirable, the
+	   Dynamic Audio Normalizer provides optional DC bias correction.
+	   With DC bias correction enabled, the Dynamic Audio Normalizer will
+	   determine the mean value, or "DC correction" offset, of each input
+	   frame and subtract that value from all of the frame's sample values
+	   which ensures those samples are centered around 0.0 again. Also, in
+	   order to avoid "gaps" at the frame boundaries, the DC correction
+	   offset values will be interpolated smoothly between neighbouring
+	   frames.
+
+       altboundary, b
+	   Enable alternative boundary mode. By default is disabled.  The
+	   Dynamic Audio Normalizer takes into account a certain neighbourhood
+	   around each frame. This includes the preceding frames as well as
+	   the subsequent frames. However, for the "boundary" frames, located
+	   at the very beginning and at the very end of the audio file, not
+	   all neighbouring frames are available. In particular, for the first
+	   few frames in the audio file, the preceding frames are not known.
+	   And, similarly, for the last few frames in the audio file, the
+	   subsequent frames are not known. Thus, the question arises which
+	   gain factors should be assumed for the missing frames in the
+	   "boundary" region. The Dynamic Audio Normalizer implements two
+	   modes to deal with this situation. The default boundary mode
+	   assumes a gain factor of exactly 1.0 for the missing frames,
+	   resulting in a smooth "fade in" and "fade out" at the beginning and
+	   at the end of the input, respectively.
+
+       compress, s
+	   Set the compress factor. In range from 0.0 to 30.0. Default is 0.0.
+	   By default, the Dynamic Audio Normalizer does not apply
+	   "traditional" compression. This means that signal peaks will not be
+	   pruned and thus the full dynamic range will be retained within each
+	   local neighbourhood. However, in some cases it may be desirable to
+	   combine the Dynamic Audio Normalizer's normalization algorithm with
+	   a more "traditional" compression.  For this purpose, the Dynamic
+	   Audio Normalizer provides an optional compression (thresholding)
+	   function. If (and only if) the compression feature is enabled, all
+	   input frames will be processed by a soft knee thresholding function
+	   prior to the actual normalization process. Put simply, the
+	   thresholding function is going to prune all samples whose magnitude
+	   exceeds a certain threshold value.  However, the Dynamic Audio
+	   Normalizer does not simply apply a fixed threshold value. Instead,
+	   the threshold value will be adjusted for each individual frame.  In
+	   general, smaller parameters result in stronger compression, and
+	   vice versa.	Values below 3.0 are not recommended, because audible
+	   distortion may appear.
+
+       threshold, t
+	   Set the target threshold value. This specifies the lowest
+	   permissible magnitude level for the audio input which will be
+	   normalized.	If input frame volume is above this value frame will
+	   be normalized.  Otherwise frame may not be normalized at all. The
+	   default value is set to 0, which means all input frames will be
+	   normalized.	This option is mostly useful if digital noise is not
+	   wanted to be amplified.
+
+       channels, h
+	   Specify which channels to filter, by default all available channels
+	   are filtered.
+
+       overlap, o
+	   Specify overlap for frames. If set to 0 (default) no frame
+	   overlapping is done.  Using >0 and <1 values will make less
+	   conservative gain adjustments, like when framelen option is set to
+	   smaller value, if framelen option value is compensated for non-zero
+	   overlap then gain adjustments will be smoother across time compared
+	   to zero overlap case.
+
+       curve, v
+	   Specify the peak mapping curve expression which is going to be used
+	   when calculating gain applied to frames. The max output frame gain
+	   will still be limited by other options mentioned previously for
+	   this filter.
+
+	   The expression can contain the following constants:
+
+	   ch  current channel number
+
+	   sn  current sample number
+
+	   nb_channels
+	       number of channels
+
+	   t   timestamp expressed in seconds
+
+	   sr  sample rate
+
+	   p   current frame peak value
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   earwax
+       Make audio easier to listen to on headphones.
+
+       This filter adds `cues' to 44.1kHz stereo (i.e. audio CD format) audio
+       so that when listened to on headphones the stereo image is moved from
+       inside your head (standard for headphones) to outside and in front of
+       the listener (standard for speakers).
+
+       Ported from SoX.
+
+   equalizer
+       Apply a two-pole peaking equalisation (EQ) filter. With this filter,
+       the signal-level at and around a selected frequency can be increased or
+       decreased, whilst (unlike bandpass and bandreject filters) that at all
+       other frequencies is unchanged.
+
+       In order to produce complex equalisation curves, this filter can be
+       given several times, each with a different central frequency.
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set the filter's central frequency in Hz.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Specify the band-width of a filter in width_type units.
+
+       gain, g
+	   Set the required gain or attenuation in dB.	Beware of clipping
+	   when using a positive gain.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Examples
+
+       o   Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
+
+		   equalizer=f=1000:t=h:width=200:g=-10
+
+       o   Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz
+	   with Q 2:
+
+		   equalizer=f=1000:t=q:w=1:g=2,equalizer=f=100:t=q:w=2:g=-5
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change equalizer frequency.	Syntax for the command is :
+	   "frequency"
+
+       width_type, t
+	   Change equalizer width_type.  Syntax for the command is :
+	   "width_type"
+
+       width, w
+	   Change equalizer width.  Syntax for the command is : "width"
+
+       gain, g
+	   Change equalizer gain.  Syntax for the command is : "gain"
+
+       mix, m
+	   Change equalizer mix.  Syntax for the command is : "mix"
+
+   extrastereo
+       Linearly increases the difference between left and right channels which
+       adds some sort of "live" effect to playback.
+
+       The filter accepts the following options:
+
+       m   Sets the difference coefficient (default: 2.5). 0.0 means mono
+	   sound (average of both channels), with 1.0 sound will be unchanged,
+	   with -1.0 left and right channels will be swapped.
+
+       c   Enable clipping. By default is enabled.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   firequalizer
+       Apply FIR Equalization using arbitrary frequency response.
+
+       The filter accepts the following option:
+
+       gain
+	   Set gain curve equation (in dB). The expression can contain
+	   variables:
+
+	   f   the evaluated frequency
+
+	   sr  sample rate
+
+	   ch  channel number, set to 0 when multichannels evaluation is
+	       disabled
+
+	   chid
+	       channel id, see libavutil/channel_layout.h, set to the first
+	       channel id when multichannels evaluation is disabled
+
+	   chs number of channels
+
+	   chlayout
+	       channel_layout, see libavutil/channel_layout.h
+
+	   and functions:
+
+	   gain_interpolate(f)
+	       interpolate gain on frequency f based on gain_entry
+
+	   cubic_interpolate(f)
+	       same as gain_interpolate, but smoother
+
+	   This option is also available as command. Default is
+	   gain_interpolate(f).
+
+       gain_entry
+	   Set gain entry for gain_interpolate function. The expression can
+	   contain functions:
+
+	   entry(f, g)
+	       store gain entry at frequency f with value g
+
+	   This option is also available as command.
+
+       delay
+	   Set filter delay in seconds. Higher value means more accurate.
+	   Default is 0.01.
+
+       accuracy
+	   Set filter accuracy in Hz. Lower value means more accurate.
+	   Default is 5.
+
+       wfunc
+	   Set window function. Acceptable values are:
+
+	   rectangular
+	       rectangular window, useful when gain curve is already smooth
+
+	   hann
+	       hann window (default)
+
+	   hamming
+	       hamming window
+
+	   blackman
+	       blackman window
+
+	   nuttall3
+	       3-terms continuous 1st derivative nuttall window
+
+	   mnuttall3
+	       minimum 3-terms discontinuous nuttall window
+
+	   nuttall
+	       4-terms continuous 1st derivative nuttall window
+
+	   bnuttall
+	       minimum 4-terms discontinuous nuttall (blackman-nuttall) window
+
+	   bharris
+	       blackman-harris window
+
+	   tukey
+	       tukey window
+
+       fixed
+	   If enabled, use fixed number of audio samples. This improves speed
+	   when filtering with large delay. Default is disabled.
+
+       multi
+	   Enable multichannels evaluation on gain. Default is disabled.
+
+       zero_phase
+	   Enable zero phase mode by subtracting timestamp to compensate
+	   delay.  Default is disabled.
+
+       scale
+	   Set scale used by gain. Acceptable values are:
+
+	   linlin
+	       linear frequency, linear gain
+
+	   linlog
+	       linear frequency, logarithmic (in dB) gain (default)
+
+	   loglin
+	       logarithmic (in octave scale where 20 Hz is 0) frequency,
+	       linear gain
+
+	   loglog
+	       logarithmic frequency, logarithmic gain
+
+       dumpfile
+	   Set file for dumping, suitable for gnuplot.
+
+       dumpscale
+	   Set scale for dumpfile. Acceptable values are same with scale
+	   option.  Default is linlog.
+
+       fft2
+	   Enable 2-channel convolution using complex FFT. This improves speed
+	   significantly.  Default is disabled.
+
+       min_phase
+	   Enable minimum phase impulse response. Default is disabled.
+
+       Examples
+
+       o   lowpass at 1000 Hz:
+
+		   firequalizer=gain='if(lt(f,1000), 0, -INF)'
+
+       o   lowpass at 1000 Hz with gain_entry:
+
+		   firequalizer=gain_entry='entry(1000,0); entry(1001, -INF)'
+
+       o   custom equalization:
+
+		   firequalizer=gain_entry='entry(100,0); entry(400, -4); entry(1000, -6); entry(2000, 0)'
+
+       o   higher delay with zero phase to compensate delay:
+
+		   firequalizer=delay=0.1:fixed=on:zero_phase=on
+
+       o   lowpass on left channel, highpass on right channel:
+
+		   firequalizer=gain='if(eq(chid,1), gain_interpolate(f), if(eq(chid,2), gain_interpolate(1e6+f), 0))'
+		   :gain_entry='entry(1000, 0); entry(1001,-INF); entry(1e6+1000,0)':multi=on
+
+   flanger
+       Apply a flanging effect to the audio.
+
+       The filter accepts the following options:
+
+       delay
+	   Set base delay in milliseconds. Range from 0 to 30. Default value
+	   is 0.
+
+       depth
+	   Set added sweep delay in milliseconds. Range from 0 to 10. Default
+	   value is 2.
+
+       regen
+	   Set percentage regeneration (delayed signal feedback). Range from
+	   -95 to 95.  Default value is 0.
+
+       width
+	   Set percentage of delayed signal mixed with original. Range from 0
+	   to 100.  Default value is 71.
+
+       speed
+	   Set sweeps per second (Hz). Range from 0.1 to 10. Default value is
+	   0.5.
+
+       shape
+	   Set swept wave shape, can be triangular or sinusoidal.  Default
+	   value is sinusoidal.
+
+       phase
+	   Set swept wave percentage-shift for multi channel. Range from 0 to
+	   100.  Default value is 25.
+
+       interp
+	   Set delay-line interpolation, linear or quadratic.  Default is
+	   linear.
+
+   haas
+       Apply Haas effect to audio.
+
+       Note that this makes most sense to apply on mono signals.  With this
+       filter applied to mono signals it give some directionality and
+       stretches its stereo image.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input level. By default is 1, or 0dB
+
+       level_out
+	   Set output level. By default is 1, or 0dB.
+
+       side_gain
+	   Set gain applied to side part of signal. By default is 1.
+
+       middle_source
+	   Set kind of middle source. Can be one of the following:
+
+	   left
+	       Pick left channel.
+
+	   right
+	       Pick right channel.
+
+	   mid Pick middle part signal of stereo image.
+
+	   side
+	       Pick side part signal of stereo image.
+
+       middle_phase
+	   Change middle phase. By default is disabled.
+
+       left_delay
+	   Set left channel delay. By default is 2.05 milliseconds.
+
+       left_balance
+	   Set left channel balance. By default is -1.
+
+       left_gain
+	   Set left channel gain. By default is 1.
+
+       left_phase
+	   Change left phase. By default is disabled.
+
+       right_delay
+	   Set right channel delay. By defaults is 2.12 milliseconds.
+
+       right_balance
+	   Set right channel balance. By default is 1.
+
+       right_gain
+	   Set right channel gain. By default is 1.
+
+       right_phase
+	   Change right phase. By default is enabled.
+
+   hdcd
+       Decodes High Definition Compatible Digital (HDCD) data. A 16-bit PCM
+       stream with embedded HDCD codes is expanded into a 20-bit PCM stream.
+
+       The filter supports the Peak Extend and Low-level Gain Adjustment
+       features of HDCD, and detects the Transient Filter flag.
+
+	       ffmpeg -i HDCD16.flac -af hdcd OUT24.flac
+
+       When using the filter with wav, note the default encoding for wav is
+       16-bit, so the resulting 20-bit stream will be truncated back to
+       16-bit. Use something like -acodec pcm_s24le after the filter to get
+       24-bit PCM output.
+
+	       ffmpeg -i HDCD16.wav -af hdcd OUT16.wav
+	       ffmpeg -i HDCD16.wav -af hdcd -c:a pcm_s24le OUT24.wav
+
+       The filter accepts the following options:
+
+       disable_autoconvert
+	   Disable any automatic format conversion or resampling in the filter
+	   graph.
+
+       process_stereo
+	   Process the stereo channels together. If target_gain does not match
+	   between channels, consider it invalid and use the last valid
+	   target_gain.
+
+       cdt_ms
+	   Set the code detect timer period in ms.
+
+       force_pe
+	   Always extend peaks above -3dBFS even if PE isn't signaled.
+
+       analyze_mode
+	   Replace audio with a solid tone and adjust the amplitude to signal
+	   some specific aspect of the decoding process. The output file can
+	   be loaded in an audio editor alongside the original to aid
+	   analysis.
+
+	   "analyze_mode=pe:force_pe=true" can be used to see all samples
+	   above the PE level.
+
+	   Modes are:
+
+	   0, off
+	       Disabled
+
+	   1, lle
+	       Gain adjustment level at each sample
+
+	   2, pe
+	       Samples where peak extend occurs
+
+	   3, cdt
+	       Samples where the code detect timer is active
+
+	   4, tgm
+	       Samples where the target gain does not match between channels
+
+   headphone
+       Apply head-related transfer functions (HRTFs) to create virtual
+       loudspeakers around the user for binaural listening via headphones.
+       The HRIRs are provided via additional streams, for each channel one
+       stereo input stream is needed.
+
+       The filter accepts the following options:
+
+       map Set mapping of input streams for convolution.  The argument is a
+	   '|'-separated list of channel names in order as they are given as
+	   additional stream inputs for filter.  This also specify number of
+	   input streams. Number of input streams must be not less than number
+	   of channels in first stream plus one.
+
+       gain
+	   Set gain applied to audio. Value is in dB. Default is 0.
+
+       type
+	   Set processing type. Can be time or freq. time is processing audio
+	   in time domain which is slow.  freq is processing audio in
+	   frequency domain which is fast.  Default is freq.
+
+       lfe Set custom gain for LFE channels. Value is in dB. Default is 0.
+
+       size
+	   Set size of frame in number of samples which will be processed at
+	   once.  Default value is 1024. Allowed range is from 1024 to 96000.
+
+       hrir
+	   Set format of hrir stream.  Default value is stereo. Alternative
+	   value is multich.  If value is set to stereo, number of additional
+	   streams should be greater or equal to number of input channels in
+	   first input stream.	Also each additional stream should have stereo
+	   number of channels.	If value is set to multich, number of
+	   additional streams should be exactly one. Also number of input
+	   channels of additional stream should be equal or greater than twice
+	   number of channels of first input stream.
+
+       Examples
+
+       o   Full example using wav files as coefficients with amovie filters
+	   for 7.1 downmix, each amovie filter use stereo file with IR
+	   coefficients as input.  The files give coefficients for each
+	   position of virtual loudspeaker:
+
+		   ffmpeg -i input.wav
+		   -filter_complex "amovie=azi_270_ele_0_DFC.wav[sr];amovie=azi_90_ele_0_DFC.wav[sl];amovie=azi_225_ele_0_DFC.wav[br];amovie=azi_135_ele_0_DFC.wav[bl];amovie=azi_0_ele_0_DFC.wav,asplit[fc][lfe];amovie=azi_35_ele_0_DFC.wav[fl];amovie=azi_325_ele_0_DFC.wav[fr];[0:a][fl][fr][fc][lfe][bl][br][sl][sr]headphone=FL|FR|FC|LFE|BL|BR|SL|SR"
+		   output.wav
+
+       o   Full example using wav files as coefficients with amovie filters
+	   for 7.1 downmix, but now in multich hrir format.
+
+		   ffmpeg -i input.wav -filter_complex "amovie=minp.wav[hrirs];[0:a][hrirs]headphone=map=FL|FR|FC|LFE|BL|BR|SL|SR:hrir=multich"
+		   output.wav
+
+   highpass
+       Apply a high-pass filter with 3dB point frequency.  The filter can be
+       either single-pole, or double-pole (the default).  The filter roll off
+       at 6dB per pole per octave (20dB per pole per decade).
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set frequency in Hz. Default is 3000.
+
+       poles, p
+	   Set number of poles. Default is 2.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Specify the band-width of a filter in width_type units.  Applies
+	   only to double-pole filter.	The default is 0.707q and gives a
+	   Butterworth response.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change highpass frequency.  Syntax for the command is : "frequency"
+
+       width_type, t
+	   Change highpass width_type.	Syntax for the command is :
+	   "width_type"
+
+       width, w
+	   Change highpass width.  Syntax for the command is : "width"
+
+       mix, m
+	   Change highpass mix.  Syntax for the command is : "mix"
+
+   join
+       Join multiple input streams into one multi-channel stream.
+
+       It accepts the following parameters:
+
+       inputs
+	   The number of input streams. It defaults to 2.
+
+       channel_layout
+	   The desired output channel layout. It defaults to stereo.
+
+       map Map channels from inputs to output. The argument is a '|'-separated
+	   list of mappings, each in the "input_idx.in_channel-out_channel"
+	   form. input_idx is the 0-based index of the input stream.
+	   in_channel can be either the name of the input channel (e.g. FL for
+	   front left) or its index in the specified input stream. out_channel
+	   is the name of the output channel.
+
+       The filter will attempt to guess the mappings when they are not
+       specified explicitly. It does so by first trying to find an unused
+       matching input channel and if that fails it picks the first unused
+       input channel.
+
+       Join 3 inputs (with properly set channel layouts):
+
+	       ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
+
+       Build a 5.1 output from 6 single-channel streams:
+
+	       ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
+	       'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
+	       out
+
+   ladspa
+       Load a LADSPA (Linux Audio Developer's Simple Plugin API) plugin.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-ladspa".
+
+       file, f
+	   Specifies the name of LADSPA plugin library to load. If the
+	   environment variable LADSPA_PATH is defined, the LADSPA plugin is
+	   searched in each one of the directories specified by the colon
+	   separated list in LADSPA_PATH, otherwise in the standard LADSPA
+	   paths, which are in this order: HOME/.ladspa/lib/,
+	   /usr/local/lib/ladspa/, /usr/lib/ladspa/.
+
+       plugin, p
+	   Specifies the plugin within the library. Some libraries contain
+	   only one plugin, but others contain many of them. If this is not
+	   set filter will list all available plugins within the specified
+	   library.
+
+       controls, c
+	   Set the '|' separated list of controls which are zero or more
+	   floating point values that determine the behavior of the loaded
+	   plugin (for example delay, threshold or gain).  Controls need to be
+	   defined using the following syntax:
+	   c0=value0|c1=value1|c2=value2|..., where valuei is the value set on
+	   the i-th control.  Alternatively they can be also defined using the
+	   following syntax: value0|value1|value2|..., where valuei is the
+	   value set on the i-th control.  If controls is set to "help", all
+	   available controls and their valid ranges are printed.
+
+       sample_rate, s
+	   Specify the sample rate, default to 44100. Only used if plugin have
+	   zero inputs.
+
+       nb_samples, n
+	   Set the number of samples per channel per each output frame,
+	   default is 1024. Only used if plugin have zero inputs.
+
+       duration, d
+	   Set the minimum duration of the sourced audio. See the Time
+	   duration section in the ffmpeg-utils(1) manual for the accepted
+	   syntax.  Note that the resulting duration may be greater than the
+	   specified duration, as the generated audio is always cut at the end
+	   of a complete frame.  If not specified, or the expressed duration
+	   is negative, the audio is supposed to be generated forever.	Only
+	   used if plugin have zero inputs.
+
+       latency, l
+	   Enable latency compensation, by default is disabled.  Only used if
+	   plugin have inputs.
+
+       Examples
+
+       o   List all available plugins within amp (LADSPA example plugin)
+	   library:
+
+		   ladspa=file=amp
+
+       o   List all available controls and their valid ranges for "vcf_notch"
+	   plugin from "VCF" library:
+
+		   ladspa=f=vcf:p=vcf_notch:c=help
+
+       o   Simulate low quality audio equipment using "Computer Music Toolkit"
+	   (CMT) plugin library:
+
+		   ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
+
+       o   Add reverberation to the audio using TAP-plugins (Tom's Audio
+	   Processing plugins):
+
+		   ladspa=file=tap_reverb:tap_reverb
+
+       o   Generate white noise, with 0.2 amplitude:
+
+		   ladspa=file=cmt:noise_source_white:c=c0=.2
+
+       o   Generate 20 bpm clicks using plugin "C* Click - Metronome" from the
+	   "C* Audio Plugin Suite" (CAPS) library:
+
+		   ladspa=file=caps:Click:c=c1=20'
+
+       o   Apply "C* Eq10X2 - Stereo 10-band equaliser" effect:
+
+		   ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
+
+       o   Increase volume by 20dB using fast lookahead limiter from Steve
+	   Harris "SWH Plugins" collection:
+
+		   ladspa=fast_lookahead_limiter_1913:fastLookaheadLimiter:20|0|2
+
+       o   Attenuate low frequencies using Multiband EQ from Steve Harris "SWH
+	   Plugins" collection:
+
+		   ladspa=mbeq_1197:mbeq:-24|-24|-24|0|0|0|0|0|0|0|0|0|0|0|0
+
+       o   Reduce stereo image using "Narrower" from the "C* Audio Plugin
+	   Suite" (CAPS) library:
+
+		   ladspa=caps:Narrower
+
+       o   Another white noise, now using "C* Audio Plugin Suite" (CAPS)
+	   library:
+
+		   ladspa=caps:White:.2
+
+       o   Some fractal noise, using "C* Audio Plugin Suite" (CAPS) library:
+
+		   ladspa=caps:Fractal:c=c1=1
+
+       o   Dynamic volume normalization using "VLevel" plugin:
+
+		   ladspa=vlevel-ladspa:vlevel_mono
+
+       Commands
+
+       This filter supports the following commands:
+
+       cN  Modify the N-th control value.
+
+	   If the specified value is not valid, it is ignored and prior one is
+	   kept.
+
+   loudnorm
+       EBU R128 loudness normalization. Includes both dynamic and linear
+       normalization modes.  Support for both single pass (livestreams, files)
+       and double pass (files) modes.  This algorithm can target IL, LRA, and
+       maximum true peak. In dynamic mode, to accurately detect true peaks,
+       the audio stream will be upsampled to 192 kHz.  Use the "-ar" option or
+       "aresample" filter to explicitly set an output sample rate.
+
+       The filter accepts the following options:
+
+       I, i
+	   Set integrated loudness target.  Range is -70.0 - -5.0. Default
+	   value is -24.0.
+
+       LRA, lra
+	   Set loudness range target.  Range is 1.0 - 50.0. Default value is
+	   7.0.
+
+       TP, tp
+	   Set maximum true peak.  Range is -9.0 - +0.0. Default value is
+	   -2.0.
+
+       measured_I, measured_i
+	   Measured IL of input file.  Range is -99.0 - +0.0.
+
+       measured_LRA, measured_lra
+	   Measured LRA of input file.	Range is  0.0 - 99.0.
+
+       measured_TP, measured_tp
+	   Measured true peak of input file.  Range is	-99.0 - +99.0.
+
+       measured_thresh
+	   Measured threshold of input file.  Range is -99.0 - +0.0.
+
+       offset
+	   Set offset gain. Gain is applied before the true-peak limiter.
+	   Range is  -99.0 - +99.0. Default is +0.0.
+
+       linear
+	   Normalize by linearly scaling the source audio.  "measured_I",
+	   "measured_LRA", "measured_TP", and "measured_thresh" must all be
+	   specified. Target LRA shouldn't be lower than source LRA and the
+	   change in integrated loudness shouldn't result in a true peak which
+	   exceeds the target TP. If any of these conditions aren't met,
+	   normalization mode will revert to dynamic.  Options are "true" or
+	   "false". Default is "true".
+
+       dual_mono
+	   Treat mono input files as "dual-mono". If a mono file is intended
+	   for playback on a stereo system, its EBU R128 measurement will be
+	   perceptually incorrect.  If set to "true", this option will
+	   compensate for this effect.	Multi-channel input files are not
+	   affected by this option.  Options are true or false. Default is
+	   false.
+
+       print_format
+	   Set print format for stats. Options are summary, json, or none.
+	   Default value is none.
+
+   lowpass
+       Apply a low-pass filter with 3dB point frequency.  The filter can be
+       either single-pole or double-pole (the default).  The filter roll off
+       at 6dB per pole per octave (20dB per pole per decade).
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set frequency in Hz. Default is 500.
+
+       poles, p
+	   Set number of poles. Default is 2.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Specify the band-width of a filter in width_type units.  Applies
+	   only to double-pole filter.	The default is 0.707q and gives a
+	   Butterworth response.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Examples
+
+       o   Lowpass only LFE channel, it LFE is not present it does nothing:
+
+		   lowpass=c=LFE
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change lowpass frequency.  Syntax for the command is : "frequency"
+
+       width_type, t
+	   Change lowpass width_type.  Syntax for the command is :
+	   "width_type"
+
+       width, w
+	   Change lowpass width.  Syntax for the command is : "width"
+
+       mix, m
+	   Change lowpass mix.	Syntax for the command is : "mix"
+
+   lv2
+       Load a LV2 (LADSPA Version 2) plugin.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-lv2".
+
+       plugin, p
+	   Specifies the plugin URI. You may need to escape ':'.
+
+       controls, c
+	   Set the '|' separated list of controls which are zero or more
+	   floating point values that determine the behavior of the loaded
+	   plugin (for example delay, threshold or gain).  If controls is set
+	   to "help", all available controls and their valid ranges are
+	   printed.
+
+       sample_rate, s
+	   Specify the sample rate, default to 44100. Only used if plugin have
+	   zero inputs.
+
+       nb_samples, n
+	   Set the number of samples per channel per each output frame,
+	   default is 1024. Only used if plugin have zero inputs.
+
+       duration, d
+	   Set the minimum duration of the sourced audio. See the Time
+	   duration section in the ffmpeg-utils(1) manual for the accepted
+	   syntax.  Note that the resulting duration may be greater than the
+	   specified duration, as the generated audio is always cut at the end
+	   of a complete frame.  If not specified, or the expressed duration
+	   is negative, the audio is supposed to be generated forever.	Only
+	   used if plugin have zero inputs.
+
+       Examples
+
+       o   Apply bass enhancer plugin from Calf:
+
+		   lv2=p=http\\\\://calf.sourceforge.net/plugins/BassEnhancer:c=amount=2
+
+       o   Apply vinyl plugin from Calf:
+
+		   lv2=p=http\\\\://calf.sourceforge.net/plugins/Vinyl:c=drone=0.2|aging=0.5
+
+       o   Apply bit crusher plugin from ArtyFX:
+
+		   lv2=p=http\\\\://www.openavproductions.com/artyfx#bitta:c=crush=0.3
+
+       Commands
+
+       This filter supports all options that are exported by plugin as
+       commands.
+
+   mcompand
+       Multiband Compress or expand the audio's dynamic range.
+
+       The input audio is divided into bands using 4th order Linkwitz-Riley
+       IIRs.  This is akin to the crossover of a loudspeaker, and results in
+       flat frequency response when absent compander action.
+
+       It accepts the following parameters:
+
+       args
+	   This option syntax is: attack,decay,[attack,decay..] soft-knee
+	   points crossover_frequency [delay [initial_volume [gain]]] |
+	   attack,decay ...  For explanation of each item refer to compand
+	   filter documentation.
+
+   pan
+       Mix channels with specific gain levels. The filter accepts the output
+       channel layout followed by a set of channels definitions.
+
+       This filter is also designed to efficiently remap the channels of an
+       audio stream.
+
+       The filter accepts parameters of the form: "l|outdef|outdef|..."
+
+       l   output channel layout or number of channels
+
+       outdef
+	   output channel specification, of the form:
+	   "out_name=[gain*]in_name[(+-)[gain*]in_name...]"
+
+       out_name
+	   output channel to define, either a channel name (FL, FR, etc.) or a
+	   channel number (c0, c1, etc.)
+
+       gain
+	   multiplicative coefficient for the channel, 1 leaving the volume
+	   unchanged
+
+       in_name
+	   input channel to use, see out_name for details; it is not possible
+	   to mix named and numbered input channels
+
+       If the `=' in a channel specification is replaced by `<', then the
+       gains for that specification will be renormalized so that the total is
+       1, thus avoiding clipping noise.
+
+       Mixing examples
+
+       For example, if you want to down-mix from stereo to mono, but with a
+       bigger factor for the left channel:
+
+	       pan=1c|c0=0.9*c0+0.1*c1
+
+       A customized down-mix to stereo that works automatically for 3-, 4-, 5-
+       and 7-channels surround:
+
+	       pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
+
+       Note that ffmpeg integrates a default down-mix (and up-mix) system that
+       should be preferred (see "-ac" option) unless you have very specific
+       needs.
+
+       Remapping examples
+
+       The channel remapping will be effective if, and only if:
+
+       *<gain coefficients are zeroes or ones,>
+       *<only one input per channel output,>
+
+       If all these conditions are satisfied, the filter will notify the user
+       ("Pure channel mapping detected"), and use an optimized and lossless
+       method to do the remapping.
+
+       For example, if you have a 5.1 source and want a stereo audio stream by
+       dropping the extra channels:
+
+	       pan="stereo| c0=FL | c1=FR"
+
+       Given the same source, you can also switch front left and front right
+       channels and keep the input channel layout:
+
+	       pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
+
+       If the input is a stereo audio stream, you can mute the front left
+       channel (and still keep the stereo channel layout) with:
+
+	       pan="stereo|c1=c1"
+
+       Still with a stereo audio stream input, you can copy the right channel
+       in both front left and right:
+
+	       pan="stereo| c0=FR | c1=FR"
+
+   replaygain
+       ReplayGain scanner filter. This filter takes an audio stream as an
+       input and outputs it unchanged.	At end of filtering it displays
+       "track_gain" and "track_peak".
+
+   resample
+       Convert the audio sample format, sample rate and channel layout. It is
+       not meant to be used directly.
+
+   rubberband
+       Apply time-stretching and pitch-shifting with librubberband.
+
+       To enable compilation of this filter, you need to configure FFmpeg with
+       "--enable-librubberband".
+
+       The filter accepts the following options:
+
+       tempo
+	   Set tempo scale factor.
+
+       pitch
+	   Set pitch scale factor.
+
+       transients
+	   Set transients detector.  Possible values are:
+
+	   crisp
+	   mixed
+	   smooth
+       detector
+	   Set detector.  Possible values are:
+
+	   compound
+	   percussive
+	   soft
+       phase
+	   Set phase.  Possible values are:
+
+	   laminar
+	   independent
+       window
+	   Set processing window size.	Possible values are:
+
+	   standard
+	   short
+	   long
+       smoothing
+	   Set smoothing.  Possible values are:
+
+	   off
+	   on
+       formant
+	   Enable formant preservation when shift pitching.  Possible values
+	   are:
+
+	   shifted
+	   preserved
+       pitchq
+	   Set pitch quality.  Possible values are:
+
+	   quality
+	   speed
+	   consistency
+       channels
+	   Set channels.  Possible values are:
+
+	   apart
+	   together
+
+       Commands
+
+       This filter supports the following commands:
+
+       tempo
+	   Change filter tempo scale factor.  Syntax for the command is :
+	   "tempo"
+
+       pitch
+	   Change filter pitch scale factor.  Syntax for the command is :
+	   "pitch"
+
+   sidechaincompress
+       This filter acts like normal compressor but has the ability to compress
+       detected signal using second input signal.  It needs two input streams
+       and returns one output stream.  First input stream will be processed
+       depending on second stream signal.  The filtered signal then can be
+       filtered with other filters in later stages of processing. See pan and
+       amerge filter.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input gain. Default is 1. Range is between 0.015625 and 64.
+
+       mode
+	   Set mode of compressor operation. Can be "upward" or "downward".
+	   Default is "downward".
+
+       threshold
+	   If a signal of second stream raises above this level it will affect
+	   the gain reduction of first stream.	By default is 0.125. Range is
+	   between 0.00097563 and 1.
+
+       ratio
+	   Set a ratio about which the signal is reduced. 1:2 means that if
+	   the level raised 4dB above the threshold, it will be only 2dB above
+	   after the reduction.  Default is 2. Range is between 1 and 20.
+
+       attack
+	   Amount of milliseconds the signal has to rise above the threshold
+	   before gain reduction starts. Default is 20. Range is between 0.01
+	   and 2000.
+
+       release
+	   Amount of milliseconds the signal has to fall below the threshold
+	   before reduction is decreased again. Default is 250. Range is
+	   between 0.01 and 9000.
+
+       makeup
+	   Set the amount by how much signal will be amplified after
+	   processing.	Default is 1. Range is from 1 to 64.
+
+       knee
+	   Curve the sharp knee around the threshold to enter gain reduction
+	   more softly.  Default is 2.82843. Range is between 1 and 8.
+
+       link
+	   Choose if the "average" level between all channels of side-chain
+	   stream or the louder("maximum") channel of side-chain stream
+	   affects the reduction. Default is "average".
+
+       detection
+	   Should the exact signal be taken in case of "peak" or an RMS one in
+	   case of "rms". Default is "rms" which is mainly smoother.
+
+       level_sc
+	   Set sidechain gain. Default is 1. Range is between 0.015625 and 64.
+
+       mix How much to use compressed signal in output. Default is 1.  Range
+	   is between 0 and 1.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Full ffmpeg example taking 2 audio inputs, 1st input to be
+	   compressed depending on the signal of 2nd input and later
+	   compressed signal to be merged with 2nd input:
+
+		   ffmpeg -i main.flac -i sidechain.flac -filter_complex "[1:a]asplit=2[sc][mix];[0:a][sc]sidechaincompress[compr];[compr][mix]amerge"
+
+   sidechaingate
+       A sidechain gate acts like a normal (wideband) gate but has the ability
+       to filter the detected signal before sending it to the gain reduction
+       stage.  Normally a gate uses the full range signal to detect a level
+       above the threshold.  For example: If you cut all lower frequencies
+       from your sidechain signal the gate will decrease the volume of your
+       track only if not enough highs appear. With this technique you are able
+       to reduce the resonation of a natural drum or remove "rumbling" of
+       muted strokes from a heavily distorted guitar.  It needs two input
+       streams and returns one output stream.  First input stream will be
+       processed depending on second stream signal.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input level before filtering.  Default is 1. Allowed range is
+	   from 0.015625 to 64.
+
+       mode
+	   Set the mode of operation. Can be "upward" or "downward".  Default
+	   is "downward". If set to "upward" mode, higher parts of signal will
+	   be amplified, expanding dynamic range in upward direction.
+	   Otherwise, in case of "downward" lower parts of signal will be
+	   reduced.
+
+       range
+	   Set the level of gain reduction when the signal is below the
+	   threshold.  Default is 0.06125. Allowed range is from 0 to 1.
+	   Setting this to 0 disables reduction and then filter behaves like
+	   expander.
+
+       threshold
+	   If a signal rises above this level the gain reduction is released.
+	   Default is 0.125. Allowed range is from 0 to 1.
+
+       ratio
+	   Set a ratio about which the signal is reduced.  Default is 2.
+	   Allowed range is from 1 to 9000.
+
+       attack
+	   Amount of milliseconds the signal has to rise above the threshold
+	   before gain reduction stops.  Default is 20 milliseconds. Allowed
+	   range is from 0.01 to 9000.
+
+       release
+	   Amount of milliseconds the signal has to fall below the threshold
+	   before the reduction is increased again. Default is 250
+	   milliseconds.  Allowed range is from 0.01 to 9000.
+
+       makeup
+	   Set amount of amplification of signal after processing.  Default is
+	   1. Allowed range is from 1 to 64.
+
+       knee
+	   Curve the sharp knee around the threshold to enter gain reduction
+	   more softly.  Default is 2.828427125. Allowed range is from 1 to 8.
+
+       detection
+	   Choose if exact signal should be taken for detection or an RMS like
+	   one.  Default is rms. Can be peak or rms.
+
+       link
+	   Choose if the average level between all channels or the louder
+	   channel affects the reduction.  Default is average. Can be average
+	   or maximum.
+
+       level_sc
+	   Set sidechain gain. Default is 1. Range is from 0.015625 to 64.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   silencedetect
+       Detect silence in an audio stream.
+
+       This filter logs a message when it detects that the input audio volume
+       is less or equal to a noise tolerance value for a duration greater or
+       equal to the minimum detected noise duration.
+
+       The printed times and duration are expressed in seconds. The
+       "lavfi.silence_start" or "lavfi.silence_start.X" metadata key is set on
+       the first frame whose timestamp equals or exceeds the detection
+       duration and it contains the timestamp of the first frame of the
+       silence.
+
+       The "lavfi.silence_duration" or "lavfi.silence_duration.X" and
+       "lavfi.silence_end" or "lavfi.silence_end.X" metadata keys are set on
+       the first frame after the silence. If mono is enabled, and each channel
+       is evaluated separately, the ".X" suffixed keys are used, and "X"
+       corresponds to the channel number.
+
+       The filter accepts the following options:
+
+       noise, n
+	   Set noise tolerance. Can be specified in dB (in case "dB" is
+	   appended to the specified value) or amplitude ratio. Default is
+	   -60dB, or 0.001.
+
+       duration, d
+	   Set silence duration until notification (default is 2 seconds). See
+	   the Time duration section in the ffmpeg-utils(1) manual for the
+	   accepted syntax.
+
+       mono, m
+	   Process each channel separately, instead of combined. By default is
+	   disabled.
+
+       Examples
+
+       o   Detect 5 seconds of silence with -50dB noise tolerance:
+
+		   silencedetect=n=-50dB:d=5
+
+       o   Complete example with ffmpeg to detect silence with 0.0001 noise
+	   tolerance in silence.mp3:
+
+		   ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
+
+   silenceremove
+       Remove silence from the beginning, middle or end of the audio.
+
+       The filter accepts the following options:
+
+       start_periods
+	   This value is used to indicate if audio should be trimmed at
+	   beginning of the audio. A value of zero indicates no silence should
+	   be trimmed from the beginning. When specifying a non-zero value, it
+	   trims audio up until it finds non-silence. Normally, when trimming
+	   silence from beginning of audio the start_periods will be 1 but it
+	   can be increased to higher values to trim all audio up to specific
+	   count of non-silence periods.  Default value is 0.
+
+       start_duration
+	   Specify the amount of time that non-silence must be detected before
+	   it stops trimming audio. By increasing the duration, bursts of
+	   noises can be treated as silence and trimmed off. Default value is
+	   0.
+
+       start_threshold
+	   This indicates what sample value should be treated as silence. For
+	   digital audio, a value of 0 may be fine but for audio recorded from
+	   analog, you may wish to increase the value to account for
+	   background noise.  Can be specified in dB (in case "dB" is appended
+	   to the specified value) or amplitude ratio. Default value is 0.
+
+       start_silence
+	   Specify max duration of silence at beginning that will be kept
+	   after trimming. Default is 0, which is equal to trimming all
+	   samples detected as silence.
+
+       start_mode
+	   Specify mode of detection of silence end in start of multi-channel
+	   audio.  Can be any or all. Default is any.  With any, any sample
+	   that is detected as non-silence will cause stopped trimming of
+	   silence.  With all, only if all channels are detected as non-
+	   silence will cause stopped trimming of silence.
+
+       stop_periods
+	   Set the count for trimming silence from the end of audio.  To
+	   remove silence from the middle of a file, specify a stop_periods
+	   that is negative. This value is then treated as a positive value
+	   and is used to indicate the effect should restart processing as
+	   specified by start_periods, making it suitable for removing periods
+	   of silence in the middle of the audio.  Default value is 0.
+
+       stop_duration
+	   Specify a duration of silence that must exist before audio is not
+	   copied any more. By specifying a higher duration, silence that is
+	   wanted can be left in the audio.  Default value is 0.
+
+       stop_threshold
+	   This is the same as start_threshold but for trimming silence from
+	   the end of audio.  Can be specified in dB (in case "dB" is appended
+	   to the specified value) or amplitude ratio. Default value is 0.
+
+       stop_silence
+	   Specify max duration of silence at end that will be kept after
+	   trimming. Default is 0, which is equal to trimming all samples
+	   detected as silence.
+
+       stop_mode
+	   Specify mode of detection of silence start in end of multi-channel
+	   audio.  Can be any or all. Default is any.  With any, any sample
+	   that is detected as non-silence will cause stopped trimming of
+	   silence.  With all, only if all channels are detected as non-
+	   silence will cause stopped trimming of silence.
+
+       detection
+	   Set how is silence detected. Can be "rms" or "peak". Second is
+	   faster and works better with digital silence which is exactly 0.
+	   Default value is "rms".
+
+       window
+	   Set duration in number of seconds used to calculate size of window
+	   in number of samples for detecting silence.	Default value is 0.02.
+	   Allowed range is from 0 to 10.
+
+       Examples
+
+       o   The following example shows how this filter can be used to start a
+	   recording that does not contain the delay at the start which
+	   usually occurs between pressing the record button and the start of
+	   the performance:
+
+		   silenceremove=start_periods=1:start_duration=5:start_threshold=0.02
+
+       o   Trim all silence encountered from beginning to end where there is
+	   more than 1 second of silence in audio:
+
+		   silenceremove=stop_periods=-1:stop_duration=1:stop_threshold=-90dB
+
+       o   Trim all digital silence samples, using peak detection, from
+	   beginning to end where there is more than 0 samples of digital
+	   silence in audio and digital silence is detected in all channels at
+	   same positions in stream:
+
+		   silenceremove=window=0:detection=peak:stop_mode=all:start_mode=all:stop_periods=-1:stop_threshold=0
+
+   sofalizer
+       SOFAlizer uses head-related transfer functions (HRTFs) to create
+       virtual loudspeakers around the user for binaural listening via
+       headphones (audio formats up to 9 channels supported).  The HRTFs are
+       stored in SOFA files (see <http://www.sofacoustics.org/> for a
+       database).  SOFAlizer is developed at the Acoustics Research Institute
+       (ARI) of the Austrian Academy of Sciences.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-libmysofa".
+
+       The filter accepts the following options:
+
+       sofa
+	   Set the SOFA file used for rendering.
+
+       gain
+	   Set gain applied to audio. Value is in dB. Default is 0.
+
+       rotation
+	   Set rotation of virtual loudspeakers in deg. Default is 0.
+
+       elevation
+	   Set elevation of virtual speakers in deg. Default is 0.
+
+       radius
+	   Set distance in meters between loudspeakers and the listener with
+	   near-field HRTFs. Default is 1.
+
+       type
+	   Set processing type. Can be time or freq. time is processing audio
+	   in time domain which is slow.  freq is processing audio in
+	   frequency domain which is fast.  Default is freq.
+
+       speakers
+	   Set custom positions of virtual loudspeakers. Syntax for this
+	   option is: <CH> <AZIM> <ELEV>[|<CH> <AZIM> <ELEV>|...].  Each
+	   virtual loudspeaker is described with short channel name following
+	   with azimuth and elevation in degrees.  Each virtual loudspeaker
+	   description is separated by '|'.  For example to override front
+	   left and front right channel positions use: 'speakers=FL 45 15|FR
+	   345 15'.  Descriptions with unrecognised channel names are ignored.
+
+       lfegain
+	   Set custom gain for LFE channels. Value is in dB. Default is 0.
+
+       framesize
+	   Set custom frame size in number of samples. Default is 1024.
+	   Allowed range is from 1024 to 96000. Only used if option type is
+	   set to freq.
+
+       normalize
+	   Should all IRs be normalized upon importing SOFA file.  By default
+	   is enabled.
+
+       interpolate
+	   Should nearest IRs be interpolated with neighbor IRs if exact
+	   position does not match. By default is disabled.
+
+       minphase
+	   Minphase all IRs upon loading of SOFA file. By default is disabled.
+
+       anglestep
+	   Set neighbor search angle step. Only used if option interpolate is
+	   enabled.
+
+       radstep
+	   Set neighbor search radius step. Only used if option interpolate is
+	   enabled.
+
+       Examples
+
+       o   Using ClubFritz6 sofa file:
+
+		   sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=1
+
+       o   Using ClubFritz12 sofa file and bigger radius with small rotation:
+
+		   sofalizer=sofa=/path/to/ClubFritz12.sofa:type=freq:radius=2:rotation=5
+
+       o   Similar as above but with custom speaker positions for front left,
+	   front right, back left and back right and also with custom gain:
+
+		   "sofalizer=sofa=/path/to/ClubFritz6.sofa:type=freq:radius=2:speakers=FL 45|FR 315|BL 135|BR 225:gain=28"
+
+   speechnorm
+       Speech Normalizer.
+
+       This filter expands or compresses each half-cycle of audio samples
+       (local set of samples all above or all below zero and between two
+       nearest zero crossings) depending on threshold value, so audio reaches
+       target peak value under conditions controlled by below options.
+
+       The filter accepts the following options:
+
+       peak, p
+	   Set the expansion target peak value. This specifies the highest
+	   allowed absolute amplitude level for the normalized audio input.
+	   Default value is 0.95. Allowed range is from 0.0 to 1.0.
+
+       expansion, e
+	   Set the maximum expansion factor. Allowed range is from 1.0 to
+	   50.0. Default value is 2.0.	This option controls maximum local
+	   half-cycle of samples expansion. The maximum expansion would be
+	   such that local peak value reaches target peak value but never to
+	   surpass it and that ratio between new and previous peak value does
+	   not surpass this option value.
+
+       compression, c
+	   Set the maximum compression factor. Allowed range is from 1.0 to
+	   50.0. Default value is 2.0.	This option controls maximum local
+	   half-cycle of samples compression. This option is used only if
+	   threshold option is set to value greater than 0.0, then in such
+	   cases when local peak is lower or same as value set by threshold
+	   all samples belonging to that peak's half-cycle will be compressed
+	   by current compression factor.
+
+       threshold, t
+	   Set the threshold value. Default value is 0.0. Allowed range is
+	   from 0.0 to 1.0.  This option specifies which half-cycles of
+	   samples will be compressed and which will be expanded.  Any half-
+	   cycle samples with their local peak value below or same as this
+	   option value will be compressed by current compression factor,
+	   otherwise, if greater than threshold value they will be expanded
+	   with expansion factor so that it could reach peak target value but
+	   never surpass it.
+
+       raise, r
+	   Set the expansion raising amount per each half-cycle of samples.
+	   Default value is 0.001.  Allowed range is from 0.0 to 1.0. This
+	   controls how fast expansion factor is raised per each new half-
+	   cycle until it reaches expansion value.  Setting this options too
+	   high may lead to distortions.
+
+       fall, f
+	   Set the compression raising amount per each half-cycle of samples.
+	   Default value is 0.001.  Allowed range is from 0.0 to 1.0. This
+	   controls how fast compression factor is raised per each new half-
+	   cycle until it reaches compression value.
+
+       channels, h
+	   Specify which channels to filter, by default all available channels
+	   are filtered.
+
+       invert, i
+	   Enable inverted filtering, by default is disabled. This inverts
+	   interpretation of threshold option. When enabled any half-cycle of
+	   samples with their local peak value below or same as threshold
+	   option will be expanded otherwise it will be compressed.
+
+       link, l
+	   Link channels when calculating gain applied to each filtered
+	   channel sample, by default is disabled.  When disabled each
+	   filtered channel gain calculation is independent, otherwise when
+	   this option is enabled the minimum of all possible gains for each
+	   filtered channel is used.
+
+       rms, m
+	   Set the expansion target RMS value. This specifies the highest
+	   allowed RMS level for the normalized audio input. Default value is
+	   0.0, thus disabled. Allowed range is from 0.0 to 1.0.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Weak and slow amplification:
+
+		   speechnorm=e=3:r=0.00001:l=1
+
+       o   Moderate and slow amplification:
+
+		   speechnorm=e=6.25:r=0.00001:l=1
+
+       o   Strong and fast amplification:
+
+		   speechnorm=e=12.5:r=0.0001:l=1
+
+       o   Very strong and fast amplification:
+
+		   speechnorm=e=25:r=0.0001:l=1
+
+       o   Extreme and fast amplification:
+
+		   speechnorm=e=50:r=0.0001:l=1
+
+   stereotools
+       This filter has some handy utilities to manage stereo signals, for
+       converting M/S stereo recordings to L/R signal while having control
+       over the parameters or spreading the stereo image of master track.
+
+       The filter accepts the following options:
+
+       level_in
+	   Set input level before filtering for both channels. Defaults is 1.
+	   Allowed range is from 0.015625 to 64.
+
+       level_out
+	   Set output level after filtering for both channels. Defaults is 1.
+	   Allowed range is from 0.015625 to 64.
+
+       balance_in
+	   Set input balance between both channels. Default is 0.  Allowed
+	   range is from -1 to 1.
+
+       balance_out
+	   Set output balance between both channels. Default is 0.  Allowed
+	   range is from -1 to 1.
+
+       softclip
+	   Enable softclipping. Results in analog distortion instead of harsh
+	   digital 0dB clipping. Disabled by default.
+
+       mutel
+	   Mute the left channel. Disabled by default.
+
+       muter
+	   Mute the right channel. Disabled by default.
+
+       phasel
+	   Change the phase of the left channel. Disabled by default.
+
+       phaser
+	   Change the phase of the right channel. Disabled by default.
+
+       mode
+	   Set stereo mode. Available values are:
+
+	   lr>lr
+	       Left/Right to Left/Right, this is default.
+
+	   lr>ms
+	       Left/Right to Mid/Side.
+
+	   ms>lr
+	       Mid/Side to Left/Right.
+
+	   lr>ll
+	       Left/Right to Left/Left.
+
+	   lr>rr
+	       Left/Right to Right/Right.
+
+	   lr>l+r
+	       Left/Right to Left + Right.
+
+	   lr>rl
+	       Left/Right to Right/Left.
+
+	   ms>ll
+	       Mid/Side to Left/Left.
+
+	   ms>rr
+	       Mid/Side to Right/Right.
+
+	   ms>rl
+	       Mid/Side to Right/Left.
+
+	   lr>l-r
+	       Left/Right to Left - Right.
+
+       slev
+	   Set level of side signal. Default is 1.  Allowed range is from
+	   0.015625 to 64.
+
+       sbal
+	   Set balance of side signal. Default is 0.  Allowed range is from -1
+	   to 1.
+
+       mlev
+	   Set level of the middle signal. Default is 1.  Allowed range is
+	   from 0.015625 to 64.
+
+       mpan
+	   Set middle signal pan. Default is 0. Allowed range is from -1 to 1.
+
+       base
+	   Set stereo base between mono and inversed channels. Default is 0.
+	   Allowed range is from -1 to 1.
+
+       delay
+	   Set delay in milliseconds how much to delay left from right channel
+	   and vice versa. Default is 0. Allowed range is from -20 to 20.
+
+       sclevel
+	   Set S/C level. Default is 1. Allowed range is from 1 to 100.
+
+       phase
+	   Set the stereo phase in degrees. Default is 0. Allowed range is
+	   from 0 to 360.
+
+       bmode_in, bmode_out
+	   Set balance mode for balance_in/balance_out option.
+
+	   Can be one of the following:
+
+	   balance
+	       Classic balance mode. Attenuate one channel at time.  Gain is
+	       raised up to 1.
+
+	   amplitude
+	       Similar as classic mode above but gain is raised up to 2.
+
+	   power
+	       Equal power distribution, from -6dB to +6dB range.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Apply karaoke like effect:
+
+		   stereotools=mlev=0.015625
+
+       o   Convert M/S signal to L/R:
+
+		   "stereotools=mode=ms>lr"
+
+   stereowiden
+       This filter enhance the stereo effect by suppressing signal common to
+       both channels and by delaying the signal of left into right and vice
+       versa, thereby widening the stereo effect.
+
+       The filter accepts the following options:
+
+       delay
+	   Time in milliseconds of the delay of left signal into right and
+	   vice versa.	Default is 20 milliseconds.
+
+       feedback
+	   Amount of gain in delayed signal into right and vice versa. Gives a
+	   delay effect of left signal in right output and vice versa which
+	   gives widening effect. Default is 0.3.
+
+       crossfeed
+	   Cross feed of left into right with inverted phase. This helps in
+	   suppressing the mono. If the value is 1 it will cancel all the
+	   signal common to both channels. Default is 0.3.
+
+       drymix
+	   Set level of input signal of original channel. Default is 0.8.
+
+       Commands
+
+       This filter supports the all above options except "delay" as commands.
+
+   superequalizer
+       Apply 18 band equalizer.
+
+       The filter accepts the following options:
+
+       1b  Set 65Hz band gain.
+
+       2b  Set 92Hz band gain.
+
+       3b  Set 131Hz band gain.
+
+       4b  Set 185Hz band gain.
+
+       5b  Set 262Hz band gain.
+
+       6b  Set 370Hz band gain.
+
+       7b  Set 523Hz band gain.
+
+       8b  Set 740Hz band gain.
+
+       9b  Set 1047Hz band gain.
+
+       10b Set 1480Hz band gain.
+
+       11b Set 2093Hz band gain.
+
+       12b Set 2960Hz band gain.
+
+       13b Set 4186Hz band gain.
+
+       14b Set 5920Hz band gain.
+
+       15b Set 8372Hz band gain.
+
+       16b Set 11840Hz band gain.
+
+       17b Set 16744Hz band gain.
+
+       18b Set 20000Hz band gain.
+
+   surround
+       Apply audio surround upmix filter.
+
+       This filter allows to produce multichannel output from audio stream.
+
+       The filter accepts the following options:
+
+       chl_out
+	   Set output channel layout. By default, this is 5.1.
+
+	   See the Channel Layout section in the ffmpeg-utils(1) manual for
+	   the required syntax.
+
+       chl_in
+	   Set input channel layout. By default, this is stereo.
+
+	   See the Channel Layout section in the ffmpeg-utils(1) manual for
+	   the required syntax.
+
+       level_in
+	   Set input volume level. By default, this is 1.
+
+       level_out
+	   Set output volume level. By default, this is 1.
+
+       lfe Enable LFE channel output if output channel layout has it. By
+	   default, this is enabled.
+
+       lfe_low
+	   Set LFE low cut off frequency. By default, this is 128 Hz.
+
+       lfe_high
+	   Set LFE high cut off frequency. By default, this is 256 Hz.
+
+       lfe_mode
+	   Set LFE mode, can be add or sub. Default is add.  In add mode, LFE
+	   channel is created from input audio and added to output.  In sub
+	   mode, LFE channel is created from input audio and added to output
+	   but also all non-LFE output channels are subtracted with output LFE
+	   channel.
+
+       smooth
+	   Set temporal smoothness strength, used to gradually change factors
+	   when transforming stereo sound in time. Allowed range is from 0.0
+	   to 1.0.  Useful to improve output quality with focus option values
+	   greater than 0.0.  Default is 0.0. Only values inside this range
+	   and without edges are effective.
+
+       angle
+	   Set angle of stereo surround transform, Allowed range is from 0 to
+	   360.  Default is 90.
+
+       focus
+	   Set focus of stereo surround transform, Allowed range is from -1 to
+	   1.  Default is 0.
+
+       fc_in
+	   Set front center input volume. By default, this is 1.
+
+       fc_out
+	   Set front center output volume. By default, this is 1.
+
+       fl_in
+	   Set front left input volume. By default, this is 1.
+
+       fl_out
+	   Set front left output volume. By default, this is 1.
+
+       fr_in
+	   Set front right input volume. By default, this is 1.
+
+       fr_out
+	   Set front right output volume. By default, this is 1.
+
+       sl_in
+	   Set side left input volume. By default, this is 1.
+
+       sl_out
+	   Set side left output volume. By default, this is 1.
+
+       sr_in
+	   Set side right input volume. By default, this is 1.
+
+       sr_out
+	   Set side right output volume. By default, this is 1.
+
+       bl_in
+	   Set back left input volume. By default, this is 1.
+
+       bl_out
+	   Set back left output volume. By default, this is 1.
+
+       br_in
+	   Set back right input volume. By default, this is 1.
+
+       br_out
+	   Set back right output volume. By default, this is 1.
+
+       bc_in
+	   Set back center input volume. By default, this is 1.
+
+       bc_out
+	   Set back center output volume. By default, this is 1.
+
+       lfe_in
+	   Set LFE input volume. By default, this is 1.
+
+       lfe_out
+	   Set LFE output volume. By default, this is 1.
+
+       allx
+	   Set spread usage of stereo image across X axis for all channels.
+	   Allowed range is from -1 to 15.  By default this value is negative
+	   -1, and thus unused.
+
+       ally
+	   Set spread usage of stereo image across Y axis for all channels.
+	   Allowed range is from -1 to 15.  By default this value is negative
+	   -1, and thus unused.
+
+       fcx, flx, frx, blx, brx, slx, srx, bcx
+	   Set spread usage of stereo image across X axis for each channel.
+	   Allowed range is from 0.06 to 15.  By default this value is 0.5.
+
+       fcy, fly, fry, bly, bry, sly, sry, bcy
+	   Set spread usage of stereo image across Y axis for each channel.
+	   Allowed range is from 0.06 to 15.  By default this value is 0.5.
+
+       win_size
+	   Set window size. Allowed range is from 1024 to 65536. Default size
+	   is 4096.
+
+       win_func
+	   Set window function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hann, hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default is "hann".
+
+       overlap
+	   Set window overlap. If set to 1, the recommended overlap for
+	   selected window function will be picked. Default is 0.5.
+
+   tiltshelf
+       Boost or cut the lower frequencies and cut or boost higher frequencies
+       of the audio using a two-pole shelving filter with a response similar
+       to that of a standard hi-fi's tone-controls.  This is also known as
+       shelving equalisation (EQ).
+
+       The filter accepts the following options:
+
+       gain, g
+	   Give the gain at 0 Hz. Its useful range is about -20 (for a large
+	   cut) to +20 (for a large boost).  Beware of clipping when using a
+	   positive gain.
+
+       frequency, f
+	   Set the filter's central frequency and so can be used to extend or
+	   reduce the frequency range to be boosted or cut.  The default value
+	   is 3000 Hz.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Determine how steep is the filter's shelf transition.
+
+       poles, p
+	   Set number of poles. Default is 2.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports some options as commands.
+
+   treble, highshelf
+       Boost or cut treble (upper) frequencies of the audio using a two-pole
+       shelving filter with a response similar to that of a standard hi-fi's
+       tone-controls. This is also known as shelving equalisation (EQ).
+
+       The filter accepts the following options:
+
+       gain, g
+	   Give the gain at whichever is the lower of ~22 kHz and the Nyquist
+	   frequency. Its useful range is about -20 (for a large cut) to +20
+	   (for a large boost). Beware of clipping when using a positive gain.
+
+       frequency, f
+	   Set the filter's central frequency and so can be used to extend or
+	   reduce the frequency range to be boosted or cut.  The default value
+	   is 3000 Hz.
+
+       width_type, t
+	   Set method to specify band-width of filter.
+
+	   h   Hz
+
+	   q   Q-Factor
+
+	   o   octave
+
+	   s   slope
+
+	   k   kHz
+
+       width, w
+	   Determine how steep is the filter's shelf transition.
+
+       poles, p
+	   Set number of poles. Default is 2.
+
+       mix, m
+	   How much to use filtered signal in output. Default is 1.  Range is
+	   between 0 and 1.
+
+       channels, c
+	   Specify which channels to filter, by default all available are
+	   filtered.
+
+       normalize, n
+	   Normalize biquad coefficients, by default is disabled.  Enabling it
+	   will normalize magnitude response at DC to 0dB.
+
+       transform, a
+	   Set transform type of IIR filter.
+
+	   di
+	   dii
+	   tdi
+	   tdii
+	   latt
+	   svf
+	   zdf
+       precision, r
+	   Set precison of filtering.
+
+	   auto
+	       Pick automatic sample format depending on surround filters.
+
+	   s16 Always use signed 16-bit.
+
+	   s32 Always use signed 32-bit.
+
+	   f32 Always use float 32-bit.
+
+	   f64 Always use float 64-bit.
+
+       block_size, b
+	   Set block size used for reverse IIR processing. If this value is
+	   set to high enough value (higher than impulse response length
+	   truncated when reaches near zero values) filtering will become
+	   linear phase otherwise if not big enough it will just produce nasty
+	   artifacts.
+
+	   Note that filter delay will be exactly this many samples when set
+	   to non-zero value.
+
+       Commands
+
+       This filter supports the following commands:
+
+       frequency, f
+	   Change treble frequency.  Syntax for the command is : "frequency"
+
+       width_type, t
+	   Change treble width_type.  Syntax for the command is : "width_type"
+
+       width, w
+	   Change treble width.  Syntax for the command is : "width"
+
+       gain, g
+	   Change treble gain.	Syntax for the command is : "gain"
+
+       mix, m
+	   Change treble mix.  Syntax for the command is : "mix"
+
+   tremolo
+       Sinusoidal amplitude modulation.
+
+       The filter accepts the following options:
+
+       f   Modulation frequency in Hertz. Modulation frequencies in the
+	   subharmonic range (20 Hz or lower) will result in a tremolo effect.
+	   This filter may also be used as a ring modulator by specifying a
+	   modulation frequency higher than 20 Hz.  Range is 0.1 - 20000.0.
+	   Default value is 5.0 Hz.
+
+       d   Depth of modulation as a percentage. Range is 0.0 - 1.0.  Default
+	   value is 0.5.
+
+   vibrato
+       Sinusoidal phase modulation.
+
+       The filter accepts the following options:
+
+       f   Modulation frequency in Hertz.  Range is 0.1 - 20000.0. Default
+	   value is 5.0 Hz.
+
+       d   Depth of modulation as a percentage. Range is 0.0 - 1.0.  Default
+	   value is 0.5.
+
+   virtualbass
+       Apply audio Virtual Bass filter.
+
+       This filter accepts stereo input and produce stereo with LFE (2.1)
+       channels output.  The newly produced LFE channel have enhanced virtual
+       bass originally obtained from both stereo channels.  This filter
+       outputs front left and front right channels unchanged as available in
+       stereo input.
+
+       The filter accepts the following options:
+
+       cutoff
+	   Set the virtual bass cutoff frequency. Default value is 250 Hz.
+	   Allowed range is from 100 to 500 Hz.
+
+       strength
+	   Set the virtual bass strength. Allowed range is from 0.5 to 3.
+	   Default value is 3.
+
+   volume
+       Adjust the input audio volume.
+
+       It accepts the following parameters:
+
+       volume
+	   Set audio volume expression.
+
+	   Output values are clipped to the maximum value.
+
+	   The output audio volume is given by the relation:
+
+		   <output_volume> = <volume> * <input_volume>
+
+	   The default value for volume is "1.0".
+
+       precision
+	   This parameter represents the mathematical precision.
+
+	   It determines which input sample formats will be allowed, which
+	   affects the precision of the volume scaling.
+
+	   fixed
+	       8-bit fixed-point; this limits input sample format to U8, S16,
+	       and S32.
+
+	   float
+	       32-bit floating-point; this limits input sample format to FLT.
+	       (default)
+
+	   double
+	       64-bit floating-point; this limits input sample format to DBL.
+
+       replaygain
+	   Choose the behaviour on encountering ReplayGain side data in input
+	   frames.
+
+	   drop
+	       Remove ReplayGain side data, ignoring its contents (the
+	       default).
+
+	   ignore
+	       Ignore ReplayGain side data, but leave it in the frame.
+
+	   track
+	       Prefer the track gain, if present.
+
+	   album
+	       Prefer the album gain, if present.
+
+       replaygain_preamp
+	   Pre-amplification gain in dB to apply to the selected replaygain
+	   gain.
+
+	   Default value for replaygain_preamp is 0.0.
+
+       replaygain_noclip
+	   Prevent clipping by limiting the gain applied.
+
+	   Default value for replaygain_noclip is 1.
+
+       eval
+	   Set when the volume expression is evaluated.
+
+	   It accepts the following values:
+
+	   once
+	       only evaluate expression once during the filter initialization,
+	       or when the volume command is sent
+
+	   frame
+	       evaluate expression for each incoming frame
+
+	   Default value is once.
+
+       The volume expression can contain the following parameters.
+
+       n   frame number (starting at zero)
+
+       nb_channels
+	   number of channels
+
+       nb_consumed_samples
+	   number of samples consumed by the filter
+
+       nb_samples
+	   number of samples in the current frame
+
+       pos original frame position in the file
+
+       pts frame PTS
+
+       sample_rate
+	   sample rate
+
+       startpts
+	   PTS at start of stream
+
+       startt
+	   time at start of stream
+
+       t   frame time
+
+       tb  timestamp timebase
+
+       volume
+	   last set volume value
+
+       Note that when eval is set to once only the sample_rate and tb
+       variables are available, all other variables will evaluate to NAN.
+
+       Commands
+
+       This filter supports the following commands:
+
+       volume
+	   Modify the volume expression.  The command accepts the same syntax
+	   of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+       Examples
+
+       o   Halve the input audio volume:
+
+		   volume=volume=0.5
+		   volume=volume=1/2
+		   volume=volume=-6.0206dB
+
+	   In all the above example the named key for volume can be omitted,
+	   for example like in:
+
+		   volume=0.5
+
+       o   Increase input audio power by 6 decibels using fixed-point
+	   precision:
+
+		   volume=volume=6dB:precision=fixed
+
+       o   Fade volume after time 10 with an annihilation period of 5 seconds:
+
+		   volume='if(lt(t,10),1,max(1-(t-10)/5,0))':eval=frame
+
+   volumedetect
+       Detect the volume of the input video.
+
+       The filter has no parameters. It supports only 16-bit signed integer
+       samples, so the input will be converted when needed. Statistics about
+       the volume will be printed in the log when the input stream end is
+       reached.
+
+       In particular it will show the mean volume (root mean square), maximum
+       volume (on a per-sample basis), and the beginning of a histogram of the
+       registered volume values (from the maximum value to a cumulated 1/1000
+       of the samples).
+
+       All volumes are in decibels relative to the maximum PCM value.
+
+       Examples
+
+       Here is an excerpt of the output:
+
+	       [Parsed_volumedetect_0  0xa23120] mean_volume: -27 dB
+	       [Parsed_volumedetect_0  0xa23120] max_volume: -4 dB
+	       [Parsed_volumedetect_0  0xa23120] histogram_4db: 6
+	       [Parsed_volumedetect_0  0xa23120] histogram_5db: 62
+	       [Parsed_volumedetect_0  0xa23120] histogram_6db: 286
+	       [Parsed_volumedetect_0  0xa23120] histogram_7db: 1042
+	       [Parsed_volumedetect_0  0xa23120] histogram_8db: 2551
+	       [Parsed_volumedetect_0  0xa23120] histogram_9db: 4609
+	       [Parsed_volumedetect_0  0xa23120] histogram_10db: 8409
+
+       It means that:
+
+       o   The mean square energy is approximately -27 dB, or 10^-2.7.
+
+       o   The largest sample is at -4 dB, or more precisely between -4 dB and
+	   -5 dB.
+
+       o   There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
+
+       In other words, raising the volume by +4 dB does not cause any
+       clipping, raising it by +5 dB causes clipping for 6 samples, etc.
+
+AUDIO SOURCES
+       Below is a description of the currently available audio sources.
+
+   abuffer
+       Buffer audio frames, and make them available to the filter chain.
+
+       This source is mainly intended for a programmatic use, in particular
+       through the interface defined in libavfilter/buffersrc.h.
+
+       It accepts the following parameters:
+
+       time_base
+	   The timebase which will be used for timestamps of submitted frames.
+	   It must be either a floating-point number or in
+	   numerator/denominator form.
+
+       sample_rate
+	   The sample rate of the incoming audio buffers.
+
+       sample_fmt
+	   The sample format of the incoming audio buffers.  Either a sample
+	   format name or its corresponding integer representation from the
+	   enum AVSampleFormat in libavutil/samplefmt.h
+
+       channel_layout
+	   The channel layout of the incoming audio buffers.  Either a channel
+	   layout name from channel_layout_map in libavutil/channel_layout.c
+	   or its corresponding integer representation from the AV_CH_LAYOUT_*
+	   macros in libavutil/channel_layout.h
+
+       channels
+	   The number of channels of the incoming audio buffers.  If both
+	   channels and channel_layout are specified, then they must be
+	   consistent.
+
+       Examples
+
+	       abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
+
+       will instruct the source to accept planar 16bit signed stereo at
+       44100Hz.  Since the sample format with name "s16p" corresponds to the
+       number 6 and the "stereo" channel layout corresponds to the value 0x3,
+       this is equivalent to:
+
+	       abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
+
+   aevalsrc
+       Generate an audio signal specified by an expression.
+
+       This source accepts in input one or more expressions (one for each
+       channel), which are evaluated and used to generate a corresponding
+       audio signal.
+
+       This source accepts the following options:
+
+       exprs
+	   Set the '|'-separated expressions list for each separate channel.
+	   In case the channel_layout option is not specified, the selected
+	   channel layout depends on the number of provided expressions.
+	   Otherwise the last specified expression is applied to the remaining
+	   output channels.
+
+       channel_layout, c
+	   Set the channel layout. The number of channels in the specified
+	   layout must be equal to the number of specified expressions.
+
+       duration, d
+	   Set the minimum duration of the sourced audio. See the Time
+	   duration section in the ffmpeg-utils(1) manual for the accepted
+	   syntax.  Note that the resulting duration may be greater than the
+	   specified duration, as the generated audio is always cut at the end
+	   of a complete frame.
+
+	   If not specified, or the expressed duration is negative, the audio
+	   is supposed to be generated forever.
+
+       nb_samples, n
+	   Set the number of samples per channel per each output frame,
+	   default to 1024.
+
+       sample_rate, s
+	   Specify the sample rate, default to 44100.
+
+       Each expression in exprs can contain the following constants:
+
+       n   number of the evaluated sample, starting from 0
+
+       t   time of the evaluated sample expressed in seconds, starting from 0
+
+       s   sample rate
+
+       Examples
+
+       o   Generate silence:
+
+		   aevalsrc=0
+
+       o   Generate a sin signal with frequency of 440 Hz, set sample rate to
+	   8000 Hz:
+
+		   aevalsrc="sin(440*2*PI*t):s=8000"
+
+       o   Generate a two channels signal, specify the channel layout (Front
+	   Center + Back Center) explicitly:
+
+		   aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
+
+       o   Generate white noise:
+
+		   aevalsrc="-2+random(0)"
+
+       o   Generate an amplitude modulated signal:
+
+		   aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
+
+       o   Generate 2.5 Hz binaural beats on a 360 Hz carrier:
+
+		   aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
+
+   afdelaysrc
+       Generate a fractional delay FIR coefficients.
+
+       The resulting stream can be used with afir filter for filtering the
+       audio signal.
+
+       The filter accepts the following options:
+
+       delay, d
+	   Set the fractional delay. Default is 0.
+
+       sample_rate, r
+	   Set the sample rate, default is 44100.
+
+       nb_samples, n
+	   Set the number of samples per each frame. Default is 1024.
+
+       taps, t
+	   Set the number of filter coefficents in output audio stream.
+	   Default value is 0.
+
+       channel_layout, c
+	   Specifies the channel layout, and can be a string representing a
+	   channel layout.  The default value of channel_layout is "stereo".
+
+   afirsrc
+       Generate a FIR coefficients using frequency sampling method.
+
+       The resulting stream can be used with afir filter for filtering the
+       audio signal.
+
+       The filter accepts the following options:
+
+       taps, t
+	   Set number of filter coefficents in output audio stream.  Default
+	   value is 1025.
+
+       frequency, f
+	   Set frequency points from where magnitude and phase are set.  This
+	   must be in non decreasing order, and first element must be 0, while
+	   last element must be 1. Elements are separated by white spaces.
+
+       magnitude, m
+	   Set magnitude value for every frequency point set by frequency.
+	   Number of values must be same as number of frequency points.
+	   Values are separated by white spaces.
+
+       phase, p
+	   Set phase value for every frequency point set by frequency.	Number
+	   of values must be same as number of frequency points.  Values are
+	   separated by white spaces.
+
+       sample_rate, r
+	   Set sample rate, default is 44100.
+
+       nb_samples, n
+	   Set number of samples per each frame. Default is 1024.
+
+       win_func, w
+	   Set window function. Default is blackman.
+
+   anullsrc
+       The null audio source, return unprocessed audio frames. It is mainly
+       useful as a template and to be employed in analysis / debugging tools,
+       or as the source for filters which ignore the input data (for example
+       the sox synth filter).
+
+       This source accepts the following options:
+
+       channel_layout, cl
+	   Specifies the channel layout, and can be either an integer or a
+	   string representing a channel layout. The default value of
+	   channel_layout is "stereo".
+
+	   Check the channel_layout_map definition in
+	   libavutil/channel_layout.c for the mapping between strings and
+	   channel layout values.
+
+       sample_rate, r
+	   Specifies the sample rate, and defaults to 44100.
+
+       nb_samples, n
+	   Set the number of samples per requested frames.
+
+       duration, d
+	   Set the duration of the sourced audio. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.
+
+	   If not specified, or the expressed duration is negative, the audio
+	   is supposed to be generated forever.
+
+       Examples
+
+       o   Set the sample rate to 48000 Hz and the channel layout to
+	   AV_CH_LAYOUT_MONO.
+
+		   anullsrc=r=48000:cl=4
+
+       o   Do the same operation with a more obvious syntax:
+
+		   anullsrc=r=48000:cl=mono
+
+       All the parameters need to be explicitly defined.
+
+   flite
+       Synthesize a voice utterance using the libflite library.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-libflite".
+
+       Note that versions of the flite library prior to 2.0 are not thread-
+       safe.
+
+       The filter accepts the following options:
+
+       list_voices
+	   If set to 1, list the names of the available voices and exit
+	   immediately. Default value is 0.
+
+       nb_samples, n
+	   Set the maximum number of samples per frame. Default value is 512.
+
+       textfile
+	   Set the filename containing the text to speak.
+
+       text
+	   Set the text to speak.
+
+       voice, v
+	   Set the voice to use for the speech synthesis. Default value is
+	   "kal". See also the list_voices option.
+
+       Examples
+
+       o   Read from file speech.txt, and synthesize the text using the
+	   standard flite voice:
+
+		   flite=textfile=speech.txt
+
+       o   Read the specified text selecting the "slt" voice:
+
+		   flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
+
+       o   Input text to ffmpeg:
+
+		   ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
+
+       o   Make ffplay speak the specified text, using "flite" and the "lavfi"
+	   device:
+
+		   ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
+
+       For more information about libflite, check:
+       <http://www.festvox.org/flite/>
+
+   anoisesrc
+       Generate a noise audio signal.
+
+       The filter accepts the following options:
+
+       sample_rate, r
+	   Specify the sample rate. Default value is 48000 Hz.
+
+       amplitude, a
+	   Specify the amplitude (0.0 - 1.0) of the generated audio stream.
+	   Default value is 1.0.
+
+       duration, d
+	   Specify the duration of the generated audio stream. Not specifying
+	   this option results in noise with an infinite length.
+
+       color, colour, c
+	   Specify the color of noise. Available noise colors are white, pink,
+	   brown, blue, violet and velvet. Default color is white.
+
+       seed, s
+	   Specify a value used to seed the PRNG.
+
+       nb_samples, n
+	   Set the number of samples per each output frame, default is 1024.
+
+       Examples
+
+       o   Generate 60 seconds of pink noise, with a 44.1 kHz sampling rate
+	   and an amplitude of 0.5:
+
+		   anoisesrc=d=60:c=pink:r=44100:a=0.5
+
+   hilbert
+       Generate odd-tap Hilbert transform FIR coefficients.
+
+       The resulting stream can be used with afir filter for phase-shifting
+       the signal by 90 degrees.
+
+       This is used in many matrix coding schemes and for analytic signal
+       generation.  The process is often written as a multiplication by i (or
+       j), the imaginary unit.
+
+       The filter accepts the following options:
+
+       sample_rate, s
+	   Set sample rate, default is 44100.
+
+       taps, t
+	   Set length of FIR filter, default is 22051.
+
+       nb_samples, n
+	   Set number of samples per each frame.
+
+       win_func, w
+	   Set window function to be used when generating FIR coefficients.
+
+   sinc
+       Generate a sinc kaiser-windowed low-pass, high-pass, band-pass, or
+       band-reject FIR coefficients.
+
+       The resulting stream can be used with afir filter for filtering the
+       audio signal.
+
+       The filter accepts the following options:
+
+       sample_rate, r
+	   Set sample rate, default is 44100.
+
+       nb_samples, n
+	   Set number of samples per each frame. Default is 1024.
+
+       hp  Set high-pass frequency. Default is 0.
+
+       lp  Set low-pass frequency. Default is 0.  If high-pass frequency is
+	   lower than low-pass frequency and low-pass frequency is higher than
+	   0 then filter will create band-pass filter coefficients, otherwise
+	   band-reject filter coefficients.
+
+       phase
+	   Set filter phase response. Default is 50. Allowed range is from 0
+	   to 100.
+
+       beta
+	   Set Kaiser window beta.
+
+       att Set stop-band attenuation. Default is 120dB, allowed range is from
+	   40 to 180 dB.
+
+       round
+	   Enable rounding, by default is disabled.
+
+       hptaps
+	   Set number of taps for high-pass filter.
+
+       lptaps
+	   Set number of taps for low-pass filter.
+
+   sine
+       Generate an audio signal made of a sine wave with amplitude 1/8.
+
+       The audio signal is bit-exact.
+
+       The filter accepts the following options:
+
+       frequency, f
+	   Set the carrier frequency. Default is 440 Hz.
+
+       beep_factor, b
+	   Enable a periodic beep every second with frequency beep_factor
+	   times the carrier frequency. Default is 0, meaning the beep is
+	   disabled.
+
+       sample_rate, r
+	   Specify the sample rate, default is 44100.
+
+       duration, d
+	   Specify the duration of the generated audio stream.
+
+       samples_per_frame
+	   Set the number of samples per output frame.
+
+	   The expression can contain the following constants:
+
+	   n   The (sequential) number of the output audio frame, starting
+	       from 0.
+
+	   pts The PTS (Presentation TimeStamp) of the output audio frame,
+	       expressed in TB units.
+
+	   t   The PTS of the output audio frame, expressed in seconds.
+
+	   TB  The timebase of the output audio frames.
+
+	   Default is 1024.
+
+       Examples
+
+       o   Generate a simple 440 Hz sine wave:
+
+		   sine
+
+       o   Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5
+	   seconds:
+
+		   sine=220:4:d=5
+		   sine=f=220:b=4:d=5
+		   sine=frequency=220:beep_factor=4:duration=5
+
+       o   Generate a 1 kHz sine wave following "1602,1601,1602,1601,1602"
+	   NTSC pattern:
+
+		   sine=1000:samples_per_frame='st(0,mod(n,5)); 1602-not(not(eq(ld(0),1)+eq(ld(0),3)))'
+
+AUDIO SINKS
+       Below is a description of the currently available audio sinks.
+
+   abuffersink
+       Buffer audio frames, and make them available to the end of filter
+       chain.
+
+       This sink is mainly intended for programmatic use, in particular
+       through the interface defined in libavfilter/buffersink.h or the
+       options system.
+
+       It accepts a pointer to an AVABufferSinkContext structure, which
+       defines the incoming buffers' formats, to be passed as the opaque
+       parameter to "avfilter_init_filter" for initialization.
+
+   anullsink
+       Null audio sink; do absolutely nothing with the input audio. It is
+       mainly useful as a template and for use in analysis / debugging tools.
+
+VIDEO FILTERS
+       When you configure your FFmpeg build, you can disable any of the
+       existing filters using "--disable-filters".  The configure output will
+       show the video filters included in your build.
+
+       Below is a description of the currently available video filters.
+
+   addroi
+       Mark a region of interest in a video frame.
+
+       The frame data is passed through unchanged, but metadata is attached to
+       the frame indicating regions of interest which can affect the behaviour
+       of later encoding.  Multiple regions can be marked by applying the
+       filter multiple times.
+
+       x   Region distance in pixels from the left edge of the frame.
+
+       y   Region distance in pixels from the top edge of the frame.
+
+       w   Region width in pixels.
+
+       h   Region height in pixels.
+
+	   The parameters x, y, w and h are expressions, and may contain the
+	   following variables:
+
+	   iw  Width of the input frame.
+
+	   ih  Height of the input frame.
+
+       qoffset
+	   Quantisation offset to apply within the region.
+
+	   This must be a real value in the range -1 to +1.  A value of zero
+	   indicates no quality change.  A negative value asks for better
+	   quality (less quantisation), while a positive value asks for worse
+	   quality (greater quantisation).
+
+	   The range is calibrated so that the extreme values indicate the
+	   largest possible offset - if the rest of the frame is encoded with
+	   the worst possible quality, an offset of -1 indicates that this
+	   region should be encoded with the best possible quality anyway.
+	   Intermediate values are then interpolated in some codec-dependent
+	   way.
+
+	   For example, in 10-bit H.264 the quantisation parameter varies
+	   between -12 and 51.	A typical qoffset value of -1/10 therefore
+	   indicates that this region should be encoded with a QP around one-
+	   tenth of the full range better than the rest of the frame.  So, if
+	   most of the frame were to be encoded with a QP of around 30, this
+	   region would get a QP of around 24 (an offset of approximately
+	   -1/10 * (51 - -12) = -6.3).	An extreme value of -1 would indicate
+	   that this region should be encoded with the best possible quality
+	   regardless of the treatment of the rest of the frame - that is,
+	   should be encoded at a QP of -12.
+
+       clear
+	   If set to true, remove any existing regions of interest marked on
+	   the frame before adding the new one.
+
+       Examples
+
+       o   Mark the centre quarter of the frame as interesting.
+
+		   addroi=iw/4:ih/4:iw/2:ih/2:-1/10
+
+       o   Mark the 100-pixel-wide region on the left edge of the frame as
+	   very uninteresting (to be encoded at much lower quality than the
+	   rest of the frame).
+
+		   addroi=0:0:100:ih:+1/5
+
+   alphaextract
+       Extract the alpha component from the input as a grayscale video. This
+       is especially useful with the alphamerge filter.
+
+   alphamerge
+       Add or replace the alpha component of the primary input with the
+       grayscale value of a second input. This is intended for use with
+       alphaextract to allow the transmission or storage of frame sequences
+       that have alpha in a format that doesn't support an alpha channel.
+
+       For example, to reconstruct full frames from a normal YUV-encoded video
+       and a separate video created with alphaextract, you might use:
+
+	       movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
+
+   amplify
+       Amplify differences between current pixel and pixels of adjacent frames
+       in same pixel location.
+
+       This filter accepts the following options:
+
+       radius
+	   Set frame radius. Default is 2. Allowed range is from 1 to 63.  For
+	   example radius of 3 will instruct filter to calculate average of 7
+	   frames.
+
+       factor
+	   Set factor to amplify difference. Default is 2. Allowed range is
+	   from 0 to 65535.
+
+       threshold
+	   Set threshold for difference amplification. Any difference greater
+	   or equal to this value will not alter source pixel. Default is 10.
+	   Allowed range is from 0 to 65535.
+
+       tolerance
+	   Set tolerance for difference amplification. Any difference lower to
+	   this value will not alter source pixel. Default is 0.  Allowed
+	   range is from 0 to 65535.
+
+       low Set lower limit for changing source pixel. Default is 65535.
+	   Allowed range is from 0 to 65535.  This option controls maximum
+	   possible value that will decrease source pixel value.
+
+       high
+	   Set high limit for changing source pixel. Default is 65535. Allowed
+	   range is from 0 to 65535.  This option controls maximum possible
+	   value that will increase source pixel value.
+
+       planes
+	   Set which planes to filter. Default is all. Allowed range is from 0
+	   to 15.
+
+       Commands
+
+       This filter supports the following commands that corresponds to option
+       of same name:
+
+       factor
+       threshold
+       tolerance
+       low
+       high
+       planes
+
+   ass
+       Same as the subtitles filter, except that it doesn't require libavcodec
+       and libavformat to work. On the other hand, it is limited to ASS
+       (Advanced Substation Alpha) subtitles files.
+
+       This filter accepts the following option in addition to the common
+       options from the subtitles filter:
+
+       shaping
+	   Set the shaping engine
+
+	   Available values are:
+
+	   auto
+	       The default libass shaping engine, which is the best available.
+
+	   simple
+	       Fast, font-agnostic shaper that can do only substitutions
+
+	   complex
+	       Slower shaper using OpenType for substitutions and positioning
+
+	   The default is "auto".
+
+   atadenoise
+       Apply an Adaptive Temporal Averaging Denoiser to the video input.
+
+       The filter accepts the following options:
+
+       0a  Set threshold A for 1st plane. Default is 0.02.  Valid range is 0
+	   to 0.3.
+
+       0b  Set threshold B for 1st plane. Default is 0.04.  Valid range is 0
+	   to 5.
+
+       1a  Set threshold A for 2nd plane. Default is 0.02.  Valid range is 0
+	   to 0.3.
+
+       1b  Set threshold B for 2nd plane. Default is 0.04.  Valid range is 0
+	   to 5.
+
+       2a  Set threshold A for 3rd plane. Default is 0.02.  Valid range is 0
+	   to 0.3.
+
+       2b  Set threshold B for 3rd plane. Default is 0.04.  Valid range is 0
+	   to 5.
+
+	   Threshold A is designed to react on abrupt changes in the input
+	   signal and threshold B is designed to react on continuous changes
+	   in the input signal.
+
+       s   Set number of frames filter will use for averaging. Default is 9.
+	   Must be odd number in range [5, 129].
+
+       p   Set what planes of frame filter will use for averaging. Default is
+	   all.
+
+       a   Set what variant of algorithm filter will use for averaging.
+	   Default is "p" parallel.  Alternatively can be set to "s" serial.
+
+	   Parallel can be faster then serial, while other way around is never
+	   true.  Parallel will abort early on first change being greater then
+	   thresholds, while serial will continue processing other side of
+	   frames if they are equal or below thresholds.
+
+       0s
+       1s
+       2s  Set sigma for 1st plane, 2nd plane or 3rd plane. Default is 32767.
+	   Valid range is from 0 to 32767.  This options controls weight for
+	   each pixel in radius defined by size.  Default value means every
+	   pixel have same weight.  Setting this option to 0 effectively
+	   disables filtering.
+
+       Commands
+
+       This filter supports same commands as options except option "s".  The
+       command accepts the same syntax of the corresponding option.
+
+   avgblur
+       Apply average blur filter.
+
+       The filter accepts the following options:
+
+       sizeX
+	   Set horizontal radius size.
+
+       planes
+	   Set which planes to filter. By default all planes are filtered.
+
+       sizeY
+	   Set vertical radius size, if zero it will be same as "sizeX".
+	   Default is 0.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   backgroundkey
+       Turns a static background into transparency.
+
+       The filter accepts the following option:
+
+       threshold
+	   Threshold for scene change detection.
+
+       similarity
+	   Similarity percentage with the background.
+
+       blend
+	   Set the blend amount for pixels that are not similar.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   bbox
+       Compute the bounding box for the non-black pixels in the input frame
+       luminance plane.
+
+       This filter computes the bounding box containing all the pixels with a
+       luminance value greater than the minimum allowed value.	The parameters
+       describing the bounding box are printed on the filter log.
+
+       The filter accepts the following option:
+
+       min_val
+	   Set the minimal luminance value. Default is 16.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   bilateral
+       Apply bilateral filter, spatial smoothing while preserving edges.
+
+       The filter accepts the following options:
+
+       sigmaS
+	   Set sigma of gaussian function to calculate spatial weight.
+	   Allowed range is 0 to 512. Default is 0.1.
+
+       sigmaR
+	   Set sigma of gaussian function to calculate range weight.  Allowed
+	   range is 0 to 1. Default is 0.1.
+
+       planes
+	   Set planes to filter. Default is first only.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   bilateral_cuda
+       CUDA accelerated bilateral filter, an edge preserving filter.  This
+       filter is mathematically accurate thanks to the use of GPU
+       acceleration.  For best output quality, use one to one chroma
+       subsampling, i.e. yuv444p format.
+
+       The filter accepts the following options:
+
+       sigmaS
+	   Set sigma of gaussian function to calculate spatial weight, also
+	   called sigma space.	Allowed range is 0.1 to 512. Default is 0.1.
+
+       sigmaR
+	   Set sigma of gaussian function to calculate color range weight,
+	   also called sigma color.  Allowed range is 0.1 to 512. Default is
+	   0.1.
+
+       window_size
+	   Set window size of the bilateral function to determine the number
+	   of neighbours to loop on.  If the number entered is even, one will
+	   be added automatically.  Allowed range is 1 to 255. Default is 1.
+
+       Examples
+
+       o   Apply the bilateral filter on a video.
+
+		   ./ffmpeg -v verbose \
+		   -hwaccel cuda -hwaccel_output_format cuda -i input.mp4  \
+		   -init_hw_device cuda \
+		   -filter_complex \
+		   " \
+		   [0:v]scale_cuda=format=yuv444p[scaled_video];
+		   [scaled_video]bilateral_cuda=window_size=9:sigmaS=3.0:sigmaR=50.0" \
+		   -an -sn -c:v h264_nvenc -cq 20 out.mp4
+
+   bitplanenoise
+       Show and measure bit plane noise.
+
+       The filter accepts the following options:
+
+       bitplane
+	   Set which plane to analyze. Default is 1.
+
+       filter
+	   Filter out noisy pixels from "bitplane" set above.  Default is
+	   disabled.
+
+   blackdetect
+       Detect video intervals that are (almost) completely black. Can be
+       useful to detect chapter transitions, commercials, or invalid
+       recordings.
+
+       The filter outputs its detection analysis to both the log as well as
+       frame metadata. If a black segment of at least the specified minimum
+       duration is found, a line with the start and end timestamps as well as
+       duration is printed to the log with level "info". In addition, a log
+       line with level "debug" is printed per frame showing the black amount
+       detected for that frame.
+
+       The filter also attaches metadata to the first frame of a black segment
+       with key "lavfi.black_start" and to the first frame after the black
+       segment ends with key "lavfi.black_end". The value is the frame's
+       timestamp. This metadata is added regardless of the minimum duration
+       specified.
+
+       The filter accepts the following options:
+
+       black_min_duration, d
+	   Set the minimum detected black duration expressed in seconds. It
+	   must be a non-negative floating point number.
+
+	   Default value is 2.0.
+
+       picture_black_ratio_th, pic_th
+	   Set the threshold for considering a picture "black".  Express the
+	   minimum value for the ratio:
+
+		   <nb_black_pixels> / <nb_pixels>
+
+	   for which a picture is considered black.  Default value is 0.98.
+
+       pixel_black_th, pix_th
+	   Set the threshold for considering a pixel "black".
+
+	   The threshold expresses the maximum pixel luminance value for which
+	   a pixel is considered "black". The provided value is scaled
+	   according to the following equation:
+
+		   <absolute_threshold> = <luminance_minimum_value> + <pixel_black_th> * <luminance_range_size>
+
+	   luminance_range_size and luminance_minimum_value depend on the
+	   input video format, the range is [0-255] for YUV full-range formats
+	   and [16-235] for YUV non full-range formats.
+
+	   Default value is 0.10.
+
+       The following example sets the maximum pixel threshold to the minimum
+       value, and detects only black intervals of 2 or more seconds:
+
+	       blackdetect=d=2:pix_th=0.00
+
+   blackframe
+       Detect frames that are (almost) completely black. Can be useful to
+       detect chapter transitions or commercials. Output lines consist of the
+       frame number of the detected frame, the percentage of blackness, the
+       position in the file if known or -1 and the timestamp in seconds.
+
+       In order to display the output lines, you need to set the loglevel at
+       least to the AV_LOG_INFO value.
+
+       This filter exports frame metadata "lavfi.blackframe.pblack".  The
+       value represents the percentage of pixels in the picture that are below
+       the threshold value.
+
+       It accepts the following parameters:
+
+       amount
+	   The percentage of the pixels that have to be below the threshold;
+	   it defaults to 98.
+
+       threshold, thresh
+	   The threshold below which a pixel value is considered black; it
+	   defaults to 32.
+
+   blend
+       Blend two video frames into each other.
+
+       The "blend" filter takes two input streams and outputs one stream, the
+       first input is the "top" layer and second input is "bottom" layer.  By
+       default, the output terminates when the longest input terminates.
+
+       The "tblend" (time blend) filter takes two consecutive frames from one
+       single stream, and outputs the result obtained by blending the new
+       frame on top of the old frame.
+
+       A description of the accepted options follows.
+
+       c0_mode
+       c1_mode
+       c2_mode
+       c3_mode
+       all_mode
+	   Set blend mode for specific pixel component or all pixel components
+	   in case of all_mode. Default value is "normal".
+
+	   Available values for component modes are:
+
+	   addition
+	   and
+	   average
+	   bleach
+	   burn
+	   darken
+	   difference
+	   divide
+	   dodge
+	   exclusion
+	   extremity
+	   freeze
+	   geometric
+	   glow
+	   grainextract
+	   grainmerge
+	   hardlight
+	   hardmix
+	   hardoverlay
+	   harmonic
+	   heat
+	   interpolate
+	   lighten
+	   linearlight
+	   multiply
+	   multiply128
+	   negation
+	   normal
+	   or
+	   overlay
+	   phoenix
+	   pinlight
+	   reflect
+	   screen
+	   softdifference
+	   softlight
+	   stain
+	   subtract
+	   vividlight
+	   xor
+       c0_opacity
+       c1_opacity
+       c2_opacity
+       c3_opacity
+       all_opacity
+	   Set blend opacity for specific pixel component or all pixel
+	   components in case of all_opacity. Only used in combination with
+	   pixel component blend modes.
+
+       c0_expr
+       c1_expr
+       c2_expr
+       c3_expr
+       all_expr
+	   Set blend expression for specific pixel component or all pixel
+	   components in case of all_expr. Note that related mode options will
+	   be ignored if those are set.
+
+	   The expressions can use the following variables:
+
+	   N   The sequential number of the filtered frame, starting from 0.
+
+	   X
+	   Y   the coordinates of the current sample
+
+	   W
+	   H   the width and height of currently filtered plane
+
+	   SW
+	   SH  Width and height scale for the plane being filtered. It is the
+	       ratio between the dimensions of the current plane to the luma
+	       plane, e.g. for a "yuv420p" frame, the values are "1,1" for the
+	       luma plane and "0.5,0.5" for the chroma planes.
+
+	   T   Time of the current frame, expressed in seconds.
+
+	   TOP, A
+	       Value of pixel component at current location for first video
+	       frame (top layer).
+
+	   BOTTOM, B
+	       Value of pixel component at current location for second video
+	       frame (bottom layer).
+
+       The "blend" filter also supports the framesync options.
+
+       Examples
+
+       o   Apply transition from bottom layer to top layer in first 10
+	   seconds:
+
+		   blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
+
+       o   Apply linear horizontal transition from top layer to bottom layer:
+
+		   blend=all_expr='A*(X/W)+B*(1-X/W)'
+
+       o   Apply 1x1 checkerboard effect:
+
+		   blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
+
+       o   Apply uncover left effect:
+
+		   blend=all_expr='if(gte(N*SW+X,W),A,B)'
+
+       o   Apply uncover down effect:
+
+		   blend=all_expr='if(gte(Y-N*SH,0),A,B)'
+
+       o   Apply uncover up-left effect:
+
+		   blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
+
+       o   Split diagonally video and shows top and bottom layer on each side:
+
+		   blend=all_expr='if(gt(X,Y*(W/H)),A,B)'
+
+       o   Display differences between the current and the previous frame:
+
+		   tblend=all_mode=grainextract
+
+       Commands
+
+       This filter supports same commands as options.
+
+   blockdetect
+       Determines blockiness of frames without altering the input frames.
+
+       Based on Remco Muijs and Ihor Kirenko: "A no-reference blocking
+       artifact measure for adaptive video processing." 2005 13th European
+       signal processing conference.
+
+       The filter accepts the following options:
+
+       period_min
+       period_max
+	   Set minimum and maximum values for determining pixel grids
+	   (periods).  Default values are [3,24].
+
+       planes
+	   Set planes to filter. Default is first only.
+
+       Examples
+
+       o   Determine blockiness for the first plane and search for periods
+	   within [8,32]:
+
+		   blockdetect=period_min=8:period_max=32:planes=1
+
+   blurdetect
+       Determines blurriness of frames without altering the input frames.
+
+       Based on Marziliano, Pina, et al. "A no-reference perceptual blur
+       metric."  Allows for a block-based abbreviation.
+
+       The filter accepts the following options:
+
+       low
+       high
+	   Set low and high threshold values used by the Canny thresholding
+	   algorithm.
+
+	   The high threshold selects the "strong" edge pixels, which are then
+	   connected through 8-connectivity with the "weak" edge pixels
+	   selected by the low threshold.
+
+	   low and high threshold values must be chosen in the range [0,1],
+	   and low should be lesser or equal to high.
+
+	   Default value for low is "20/255", and default value for high is
+	   "50/255".
+
+       radius
+	   Define the radius to search around an edge pixel for local maxima.
+
+       block_pct
+	   Determine blurriness only for the most significant blocks, given in
+	   percentage.
+
+       block_width
+	   Determine blurriness for blocks of width block_width. If set to any
+	   value smaller 1, no blocks are used and the whole image is
+	   processed as one no matter of block_height.
+
+       block_height
+	   Determine blurriness for blocks of height block_height. If set to
+	   any value smaller 1, no blocks are used and the whole image is
+	   processed as one no matter of block_width.
+
+       planes
+	   Set planes to filter. Default is first only.
+
+       Examples
+
+       o   Determine blur for 80% of most significant 32x32 blocks:
+
+		   blurdetect=block_width=32:block_height=32:block_pct=80
+
+   bm3d
+       Denoise frames using Block-Matching 3D algorithm.
+
+       The filter accepts the following options.
+
+       sigma
+	   Set denoising strength. Default value is 1.	Allowed range is from
+	   0 to 999.9.	The denoising algorithm is very sensitive to sigma, so
+	   adjust it according to the source.
+
+       block
+	   Set local patch size. This sets dimensions in 2D.
+
+       bstep
+	   Set sliding step for processing blocks. Default value is 4.
+	   Allowed range is from 1 to 64.  Smaller values allows processing
+	   more reference blocks and is slower.
+
+       group
+	   Set maximal number of similar blocks for 3rd dimension. Default
+	   value is 1.	When set to 1, no block matching is done. Larger
+	   values allows more blocks in single group.  Allowed range is from 1
+	   to 256.
+
+       range
+	   Set radius for search block matching. Default is 9.	Allowed range
+	   is from 1 to INT32_MAX.
+
+       mstep
+	   Set step between two search locations for block matching. Default
+	   is 1.  Allowed range is from 1 to 64. Smaller is slower.
+
+       thmse
+	   Set threshold of mean square error for block matching. Valid range
+	   is 0 to INT32_MAX.
+
+       hdthr
+	   Set thresholding parameter for hard thresholding in 3D transformed
+	   domain.  Larger values results in stronger hard-thresholding
+	   filtering in frequency domain.
+
+       estim
+	   Set filtering estimation mode. Can be "basic" or "final".  Default
+	   is "basic".
+
+       ref If enabled, filter will use 2nd stream for block matching.  Default
+	   is disabled for "basic" value of estim option, and always enabled
+	   if value of estim is "final".
+
+       planes
+	   Set planes to filter. Default is all available except alpha.
+
+       Examples
+
+       o   Basic filtering with bm3d:
+
+		   bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic
+
+       o   Same as above, but filtering only luma:
+
+		   bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic:planes=1
+
+       o   Same as above, but with both estimation modes:
+
+		   split[a][b],[a]bm3d=sigma=3:block=4:bstep=2:group=1:estim=basic[a],[b][a]bm3d=sigma=3:block=4:bstep=2:group=16:estim=final:ref=1
+
+       o   Same as above, but prefilter with nlmeans filter instead:
+
+		   split[a][b],[a]nlmeans=s=3:r=7:p=3[a],[b][a]bm3d=sigma=3:block=4:bstep=2:group=16:estim=final:ref=1
+
+   boxblur
+       Apply a boxblur algorithm to the input video.
+
+       It accepts the following parameters:
+
+       luma_radius, lr
+       luma_power, lp
+       chroma_radius, cr
+       chroma_power, cp
+       alpha_radius, ar
+       alpha_power, ap
+
+       A description of the accepted options follows.
+
+       luma_radius, lr
+       chroma_radius, cr
+       alpha_radius, ar
+	   Set an expression for the box radius in pixels used for blurring
+	   the corresponding input plane.
+
+	   The radius value must be a non-negative number, and must not be
+	   greater than the value of the expression "min(w,h)/2" for the luma
+	   and alpha planes, and of "min(cw,ch)/2" for the chroma planes.
+
+	   Default value for luma_radius is "2". If not specified,
+	   chroma_radius and alpha_radius default to the corresponding value
+	   set for luma_radius.
+
+	   The expressions can contain the following constants:
+
+	   w
+	   h   The input width and height in pixels.
+
+	   cw
+	   ch  The input chroma image width and height in pixels.
+
+	   hsub
+	   vsub
+	       The horizontal and vertical chroma subsample values. For
+	       example, for the pixel format "yuv422p", hsub is 2 and vsub is
+	       1.
+
+       luma_power, lp
+       chroma_power, cp
+       alpha_power, ap
+	   Specify how many times the boxblur filter is applied to the
+	   corresponding plane.
+
+	   Default value for luma_power is 2. If not specified, chroma_power
+	   and alpha_power default to the corresponding value set for
+	   luma_power.
+
+	   A value of 0 will disable the effect.
+
+       Examples
+
+       o   Apply a boxblur filter with the luma, chroma, and alpha radii set
+	   to 2:
+
+		   boxblur=luma_radius=2:luma_power=1
+		   boxblur=2:1
+
+       o   Set the luma radius to 2, and alpha and chroma radius to 0:
+
+		   boxblur=2:1:cr=0:ar=0
+
+       o   Set the luma and chroma radii to a fraction of the video dimension:
+
+		   boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
+
+   bwdif
+       Deinterlace the input video ("bwdif" stands for "Bob Weaver
+       Deinterlacing Filter").
+
+       Motion adaptive deinterlacing based on yadif with the use of w3fdif and
+       cubic interpolation algorithms.	It accepts the following parameters:
+
+       mode
+	   The interlacing mode to adopt. It accepts one of the following
+	   values:
+
+	   0, send_frame
+	       Output one frame for each frame.
+
+	   1, send_field
+	       Output one frame for each field.
+
+	   The default value is "send_field".
+
+       parity
+	   The picture field parity assumed for the input interlaced video. It
+	   accepts one of the following values:
+
+	   0, tff
+	       Assume the top field is first.
+
+	   1, bff
+	       Assume the bottom field is first.
+
+	   -1, auto
+	       Enable automatic detection of field parity.
+
+	   The default value is "auto".  If the interlacing is unknown or the
+	   decoder does not export this information, top field first will be
+	   assumed.
+
+       deint
+	   Specify which frames to deinterlace. Accepts one of the following
+	   values:
+
+	   0, all
+	       Deinterlace all frames.
+
+	   1, interlaced
+	       Only deinterlace frames marked as interlaced.
+
+	   The default value is "all".
+
+   cas
+       Apply Contrast Adaptive Sharpen filter to video stream.
+
+       The filter accepts the following options:
+
+       strength
+	   Set the sharpening strength. Default value is 0.
+
+       planes
+	   Set planes to filter. Default value is to filter all planes except
+	   alpha plane.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   chromahold
+       Remove all color information for all colors except for certain one.
+
+       The filter accepts the following options:
+
+       color
+	   The color which will not be replaced with neutral chroma.
+
+       similarity
+	   Similarity percentage with the above color.	0.01 matches only the
+	   exact key color, while 1.0 matches everything.
+
+       blend
+	   Blend percentage.  0.0 makes pixels either fully gray, or not gray
+	   at all.  Higher values result in more preserved color.
+
+       yuv Signals that the color passed is already in YUV instead of RGB.
+
+	   Literal colors like "green" or "red" don't make sense with this
+	   enabled anymore.  This can be used to pass exact YUV values as
+	   hexadecimal numbers.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   chromakey
+       YUV colorspace color/chroma keying.
+
+       The filter accepts the following options:
+
+       color
+	   The color which will be replaced with transparency.
+
+       similarity
+	   Similarity percentage with the key color.
+
+	   0.01 matches only the exact key color, while 1.0 matches
+	   everything.
+
+       blend
+	   Blend percentage.
+
+	   0.0 makes pixels either fully transparent, or not transparent at
+	   all.
+
+	   Higher values result in semi-transparent pixels, with a higher
+	   transparency the more similar the pixels color is to the key color.
+
+       yuv Signals that the color passed is already in YUV instead of RGB.
+
+	   Literal colors like "green" or "red" don't make sense with this
+	   enabled anymore.  This can be used to pass exact YUV values as
+	   hexadecimal numbers.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+       Examples
+
+       o   Make every green pixel in the input image transparent:
+
+		   ffmpeg -i input.png -vf chromakey=green out.png
+
+       o   Overlay a greenscreen-video on top of a static black background.
+
+		   ffmpeg -f lavfi -i color=c=black:s=1280x720 -i video.mp4 -shortest -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.mkv
+
+   chromakey_cuda
+       CUDA accelerated YUV colorspace color/chroma keying.
+
+       This filter works like normal chromakey filter but operates on CUDA
+       frames.	for more details and parameters see chromakey.
+
+       Examples
+
+       o   Make all the green pixels in the input video transparent and use it
+	   as an overlay for another video:
+
+		   ./ffmpeg \
+		       -hwaccel cuda -hwaccel_output_format cuda -i input_green.mp4  \
+		       -hwaccel cuda -hwaccel_output_format cuda -i base_video.mp4 \
+		       -init_hw_device cuda \
+		       -filter_complex \
+		       " \
+			   [0:v]chromakey_cuda=0x25302D:0.1:0.12:1[overlay_video]; \
+			   [1:v]scale_cuda=format=yuv420p[base]; \
+			   [base][overlay_video]overlay_cuda" \
+		       -an -sn -c:v h264_nvenc -cq 20 output.mp4
+
+       o   Process two software sources, explicitly uploading the frames:
+
+		   ./ffmpeg -init_hw_device cuda=cuda -filter_hw_device cuda \
+		       -f lavfi -i color=size=800x600:color=white,format=yuv420p \
+		       -f lavfi -i yuvtestsrc=size=200x200,format=yuv420p \
+		       -filter_complex \
+		       " \
+			   [0]hwupload[under]; \
+			   [1]hwupload,chromakey_cuda=green:0.1:0.12[over]; \
+			   [under][over]overlay_cuda" \
+		       -c:v hevc_nvenc -cq 18 -preset slow output.mp4
+
+   chromanr
+       Reduce chrominance noise.
+
+       The filter accepts the following options:
+
+       thres
+	   Set threshold for averaging chrominance values.  Sum of absolute
+	   difference of Y, U and V pixel components of current pixel and
+	   neighbour pixels lower than this threshold will be used in
+	   averaging. Luma component is left unchanged and is copied to
+	   output.  Default value is 30. Allowed range is from 1 to 200.
+
+       sizew
+	   Set horizontal radius of rectangle used for averaging.  Allowed
+	   range is from 1 to 100. Default value is 5.
+
+       sizeh
+	   Set vertical radius of rectangle used for averaging.  Allowed range
+	   is from 1 to 100. Default value is 5.
+
+       stepw
+	   Set horizontal step when averaging. Default value is 1.  Allowed
+	   range is from 1 to 50.  Mostly useful to speed-up filtering.
+
+       steph
+	   Set vertical step when averaging. Default value is 1.  Allowed
+	   range is from 1 to 50.  Mostly useful to speed-up filtering.
+
+       threy
+	   Set Y threshold for averaging chrominance values.  Set finer
+	   control for max allowed difference between Y components of current
+	   pixel and neigbour pixels.  Default value is 200. Allowed range is
+	   from 1 to 200.
+
+       threu
+	   Set U threshold for averaging chrominance values.  Set finer
+	   control for max allowed difference between U components of current
+	   pixel and neigbour pixels.  Default value is 200. Allowed range is
+	   from 1 to 200.
+
+       threv
+	   Set V threshold for averaging chrominance values.  Set finer
+	   control for max allowed difference between V components of current
+	   pixel and neigbour pixels.  Default value is 200. Allowed range is
+	   from 1 to 200.
+
+       distance
+	   Set distance type used in calculations.
+
+	   manhattan
+	       Absolute difference.
+
+	   euclidean
+	       Difference squared.
+
+	   Default distance type is manhattan.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+   chromashift
+       Shift chroma pixels horizontally and/or vertically.
+
+       The filter accepts the following options:
+
+       cbh Set amount to shift chroma-blue horizontally.
+
+       cbv Set amount to shift chroma-blue vertically.
+
+       crh Set amount to shift chroma-red horizontally.
+
+       crv Set amount to shift chroma-red vertically.
+
+       edge
+	   Set edge mode, can be smear, default, or warp.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   ciescope
+       Display CIE color diagram with pixels overlaid onto it.
+
+       The filter accepts the following options:
+
+       system
+	   Set color system.
+
+	   ntsc, 470m
+	   ebu, 470bg
+	   smpte
+	   240m
+	   apple
+	   widergb
+	   cie1931
+	   rec709, hdtv
+	   uhdtv, rec2020
+	   dcip3
+       cie Set CIE system.
+
+	   xyy
+	   ucs
+	   luv
+       gamuts
+	   Set what gamuts to draw.
+
+	   See "system" option for available values.
+
+       size, s
+	   Set ciescope size, by default set to 512.
+
+       intensity, i
+	   Set intensity used to map input pixel values to CIE diagram.
+
+       contrast
+	   Set contrast used to draw tongue colors that are out of active
+	   color system gamut.
+
+       corrgamma
+	   Correct gamma displayed on scope, by default enabled.
+
+       showwhite
+	   Show white point on CIE diagram, by default disabled.
+
+       gamma
+	   Set input gamma. Used only with XYZ input color space.
+
+       fill
+	   Fill with CIE colors. By default is enabled.
+
+   codecview
+       Visualize information exported by some codecs.
+
+       Some codecs can export information through frames using side-data or
+       other means. For example, some MPEG based codecs export motion vectors
+       through the export_mvs flag in the codec flags2 option.
+
+       The filter accepts the following option:
+
+       block
+	   Display block partition structure using the luma plane.
+
+       mv  Set motion vectors to visualize.
+
+	   Available flags for mv are:
+
+	   pf  forward predicted MVs of P-frames
+
+	   bf  forward predicted MVs of B-frames
+
+	   bb  backward predicted MVs of B-frames
+
+       qp  Display quantization parameters using the chroma planes.
+
+       mv_type, mvt
+	   Set motion vectors type to visualize. Includes MVs from all frames
+	   unless specified by frame_type option.
+
+	   Available flags for mv_type are:
+
+	   fp  forward predicted MVs
+
+	   bp  backward predicted MVs
+
+       frame_type, ft
+	   Set frame type to visualize motion vectors of.
+
+	   Available flags for frame_type are:
+
+	   if  intra-coded frames (I-frames)
+
+	   pf  predicted frames (P-frames)
+
+	   bf  bi-directionally predicted frames (B-frames)
+
+       Examples
+
+       o   Visualize forward predicted MVs of all frames using ffplay:
+
+		   ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv_type=fp
+
+       o   Visualize multi-directionals MVs of P and B-Frames using ffplay:
+
+		   ffplay -flags2 +export_mvs input.mp4 -vf codecview=mv=pf+bf+bb
+
+   colorbalance
+       Modify intensity of primary colors (red, green and blue) of input
+       frames.
+
+       The filter allows an input frame to be adjusted in the shadows,
+       midtones or highlights regions for the red-cyan, green-magenta or blue-
+       yellow balance.
+
+       A positive adjustment value shifts the balance towards the primary
+       color, a negative value towards the complementary color.
+
+       The filter accepts the following options:
+
+       rs
+       gs
+       bs  Adjust red, green and blue shadows (darkest pixels).
+
+       rm
+       gm
+       bm  Adjust red, green and blue midtones (medium pixels).
+
+       rh
+       gh
+       bh  Adjust red, green and blue highlights (brightest pixels).
+
+	   Allowed ranges for options are "[-1.0, 1.0]". Defaults are 0.
+
+       pl  Preserve lightness when changing color balance. Default is
+	   disabled.
+
+       Examples
+
+       o   Add red color cast to shadows:
+
+		   colorbalance=rs=.3
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   colorcontrast
+       Adjust color contrast between RGB components.
+
+       The filter accepts the following options:
+
+       rc  Set the red-cyan contrast. Defaults is 0.0. Allowed range is from
+	   -1.0 to 1.0.
+
+       gm  Set the green-magenta contrast. Defaults is 0.0. Allowed range is
+	   from -1.0 to 1.0.
+
+       by  Set the blue-yellow contrast. Defaults is 0.0. Allowed range is
+	   from -1.0 to 1.0.
+
+       rcw
+       gmw
+       byw Set the weight of each "rc", "gm", "by" option value. Default value
+	   is 0.0.  Allowed range is from 0.0 to 1.0. If all weights are 0.0
+	   filtering is disabled.
+
+       pl  Set the amount of preserving lightness. Default value is 0.0.
+	   Allowed range is from 0.0 to 1.0.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   colorcorrect
+       Adjust color white balance selectively for blacks and whites.  This
+       filter operates in YUV colorspace.
+
+       The filter accepts the following options:
+
+       rl  Set the red shadow spot. Allowed range is from -1.0 to 1.0.
+	   Default value is 0.
+
+       bl  Set the blue shadow spot. Allowed range is from -1.0 to 1.0.
+	   Default value is 0.
+
+       rh  Set the red highlight spot. Allowed range is from -1.0 to 1.0.
+	   Default value is 0.
+
+       bh  Set the red highlight spot. Allowed range is from -1.0 to 1.0.
+	   Default value is 0.
+
+       saturation
+	   Set the amount of saturation. Allowed range is from -3.0 to 3.0.
+	   Default value is 1.
+
+       analyze
+	   If set to anything other than "manual" it will analyze every frame
+	   and use derived parameters for filtering output frame.
+
+	   Possible values are:
+
+	   manual
+	   average
+	   minmax
+	   median
+
+	   Default value is "manual".
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   colorchannelmixer
+       Adjust video input frames by re-mixing color channels.
+
+       This filter modifies a color channel by adding the values associated to
+       the other channels of the same pixels. For example if the value to
+       modify is red, the output value will be:
+
+	       <red>=<red>*<rr> + <blue>*<rb> + <green>*<rg> + <alpha>*<ra>
+
+       The filter accepts the following options:
+
+       rr
+       rg
+       rb
+       ra  Adjust contribution of input red, green, blue and alpha channels
+	   for output red channel.  Default is 1 for rr, and 0 for rg, rb and
+	   ra.
+
+       gr
+       gg
+       gb
+       ga  Adjust contribution of input red, green, blue and alpha channels
+	   for output green channel.  Default is 1 for gg, and 0 for gr, gb
+	   and ga.
+
+       br
+       bg
+       bb
+       ba  Adjust contribution of input red, green, blue and alpha channels
+	   for output blue channel.  Default is 1 for bb, and 0 for br, bg and
+	   ba.
+
+       ar
+       ag
+       ab
+       aa  Adjust contribution of input red, green, blue and alpha channels
+	   for output alpha channel.  Default is 1 for aa, and 0 for ar, ag
+	   and ab.
+
+	   Allowed ranges for options are "[-2.0, 2.0]".
+
+       pc  Set preserve color mode. The accepted values are:
+
+	   none
+	       Disable color preserving, this is default.
+
+	   lum Preserve luminance.
+
+	   max Preserve max value of RGB triplet.
+
+	   avg Preserve average value of RGB triplet.
+
+	   sum Preserve sum value of RGB triplet.
+
+	   nrm Preserve normalized value of RGB triplet.
+
+	   pwr Preserve power value of RGB triplet.
+
+       pa  Set the preserve color amount when changing colors. Allowed range
+	   is from "[0.0, 1.0]".  Default is 0.0, thus disabled.
+
+       Examples
+
+       o   Convert source to grayscale:
+
+		   colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
+
+       o   Simulate sepia tones:
+
+		   colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   colorize
+       Overlay a solid color on the video stream.
+
+       The filter accepts the following options:
+
+       hue Set the color hue. Allowed range is from 0 to 360.  Default value
+	   is 0.
+
+       saturation
+	   Set the color saturation. Allowed range is from 0 to 1.  Default
+	   value is 0.5.
+
+       lightness
+	   Set the color lightness. Allowed range is from 0 to 1.  Default
+	   value is 0.5.
+
+       mix Set the mix of source lightness. By default is set to 1.0.  Allowed
+	   range is from 0.0 to 1.0.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   colorkey
+       RGB colorspace color keying.  This filter operates on 8-bit RGB format
+       frames by setting the alpha component of each pixel which falls within
+       the similarity radius of the key color to 0. The alpha value for pixels
+       outside the similarity radius depends on the value of the blend option.
+
+       The filter accepts the following options:
+
+       color
+	   Set the color for which alpha will be set to 0 (full transparency).
+	   See "Color" section in the ffmpeg-utils manual.  Default is
+	   "black".
+
+       similarity
+	   Set the radius from the key color within which other colors also
+	   have full transparency.  The computed distance is related to the
+	   unit fractional distance in 3D space between the RGB values of the
+	   key color and the pixel's color. Range is 0.01 to 1.0. 0.01 matches
+	   within a very small radius around the exact key color, while 1.0
+	   matches everything.	Default is 0.01.
+
+       blend
+	   Set how the alpha value for pixels that fall outside the similarity
+	   radius is computed.	0.0 makes pixels either fully transparent or
+	   fully opaque.  Higher values result in semi-transparent pixels,
+	   with greater transparency the more similar the pixel color is to
+	   the key color.  Range is 0.0 to 1.0. Default is 0.0.
+
+       Examples
+
+       o   Make every green pixel in the input image transparent:
+
+		   ffmpeg -i input.png -vf colorkey=green out.png
+
+       o   Overlay a greenscreen-video on top of a static background image.
+
+		   ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.3:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.flv
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   colorhold
+       Remove all color information for all RGB colors except for certain one.
+
+       The filter accepts the following options:
+
+       color
+	   The color which will not be replaced with neutral gray.
+
+       similarity
+	   Similarity percentage with the above color.	0.01 matches only the
+	   exact key color, while 1.0 matches everything.
+
+       blend
+	   Blend percentage. 0.0 makes pixels fully gray.  Higher values
+	   result in more preserved color.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   colorlevels
+       Adjust video input frames using levels.
+
+       The filter accepts the following options:
+
+       rimin
+       gimin
+       bimin
+       aimin
+	   Adjust red, green, blue and alpha input black point.  Allowed
+	   ranges for options are "[-1.0, 1.0]". Defaults are 0.
+
+       rimax
+       gimax
+       bimax
+       aimax
+	   Adjust red, green, blue and alpha input white point.  Allowed
+	   ranges for options are "[-1.0, 1.0]". Defaults are 1.
+
+	   Input levels are used to lighten highlights (bright tones), darken
+	   shadows (dark tones), change the balance of bright and dark tones.
+
+       romin
+       gomin
+       bomin
+       aomin
+	   Adjust red, green, blue and alpha output black point.  Allowed
+	   ranges for options are "[0, 1.0]". Defaults are 0.
+
+       romax
+       gomax
+       bomax
+       aomax
+	   Adjust red, green, blue and alpha output white point.  Allowed
+	   ranges for options are "[0, 1.0]". Defaults are 1.
+
+	   Output levels allows manual selection of a constrained output level
+	   range.
+
+       preserve
+	   Set preserve color mode. The accepted values are:
+
+	   none
+	       Disable color preserving, this is default.
+
+	   lum Preserve luminance.
+
+	   max Preserve max value of RGB triplet.
+
+	   avg Preserve average value of RGB triplet.
+
+	   sum Preserve sum value of RGB triplet.
+
+	   nrm Preserve normalized value of RGB triplet.
+
+	   pwr Preserve power value of RGB triplet.
+
+       Examples
+
+       o   Make video output darker:
+
+		   colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
+
+       o   Increase contrast:
+
+		   colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
+
+       o   Make video output lighter:
+
+		   colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
+
+       o   Increase brightness:
+
+		   colorlevels=romin=0.5:gomin=0.5:bomin=0.5
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   colormap
+       Apply custom color maps to video stream.
+
+       This filter needs three input video streams.  First stream is video
+       stream that is going to be filtered out.  Second and third video stream
+       specify color patches for source color to target color mapping.
+
+       The filter accepts the following options:
+
+       patch_size
+	   Set the source and target video stream patch size in pixels.
+
+       nb_patches
+	   Set the max number of used patches from source and target video
+	   stream.  Default value is number of patches available in additional
+	   video streams.  Max allowed number of patches is 64.
+
+       type
+	   Set the adjustments used for target colors. Can be "relative" or
+	   "absolute".	Defaults is "absolute".
+
+       kernel
+	   Set the kernel used to measure color differences between mapped
+	   colors.
+
+	   The accepted values are:
+
+	   euclidean
+	   weuclidean
+
+	   Default is "euclidean".
+
+   colormatrix
+       Convert color matrix.
+
+       The filter accepts the following options:
+
+       src
+       dst Specify the source and destination color matrix. Both values must
+	   be specified.
+
+	   The accepted values are:
+
+	   bt709
+	       BT.709
+
+	   fcc FCC
+
+	   bt601
+	       BT.601
+
+	   bt470
+	       BT.470
+
+	   bt470bg
+	       BT.470BG
+
+	   smpte170m
+	       SMPTE-170M
+
+	   smpte240m
+	       SMPTE-240M
+
+	   bt2020
+	       BT.2020
+
+       For example to convert from BT.601 to SMPTE-240M, use the command:
+
+	       colormatrix=bt601:smpte240m
+
+   colorspace
+       Convert colorspace, transfer characteristics or color primaries.  Input
+       video needs to have an even size.
+
+       The filter accepts the following options:
+
+       all Specify all color properties at once.
+
+	   The accepted values are:
+
+	   bt470m
+	       BT.470M
+
+	   bt470bg
+	       BT.470BG
+
+	   bt601-6-525
+	       BT.601-6 525
+
+	   bt601-6-625
+	       BT.601-6 625
+
+	   bt709
+	       BT.709
+
+	   smpte170m
+	       SMPTE-170M
+
+	   smpte240m
+	       SMPTE-240M
+
+	   bt2020
+	       BT.2020
+
+       space
+	   Specify output colorspace.
+
+	   The accepted values are:
+
+	   bt709
+	       BT.709
+
+	   fcc FCC
+
+	   bt470bg
+	       BT.470BG or BT.601-6 625
+
+	   smpte170m
+	       SMPTE-170M or BT.601-6 525
+
+	   smpte240m
+	       SMPTE-240M
+
+	   ycgco
+	       YCgCo
+
+	   bt2020ncl
+	       BT.2020 with non-constant luminance
+
+       trc Specify output transfer characteristics.
+
+	   The accepted values are:
+
+	   bt709
+	       BT.709
+
+	   bt470m
+	       BT.470M
+
+	   bt470bg
+	       BT.470BG
+
+	   gamma22
+	       Constant gamma of 2.2
+
+	   gamma28
+	       Constant gamma of 2.8
+
+	   smpte170m
+	       SMPTE-170M, BT.601-6 625 or BT.601-6 525
+
+	   smpte240m
+	       SMPTE-240M
+
+	   srgb
+	       SRGB
+
+	   iec61966-2-1
+	       iec61966-2-1
+
+	   iec61966-2-4
+	       iec61966-2-4
+
+	   xvycc
+	       xvycc
+
+	   bt2020-10
+	       BT.2020 for 10-bits content
+
+	   bt2020-12
+	       BT.2020 for 12-bits content
+
+       primaries
+	   Specify output color primaries.
+
+	   The accepted values are:
+
+	   bt709
+	       BT.709
+
+	   bt470m
+	       BT.470M
+
+	   bt470bg
+	       BT.470BG or BT.601-6 625
+
+	   smpte170m
+	       SMPTE-170M or BT.601-6 525
+
+	   smpte240m
+	       SMPTE-240M
+
+	   film
+	       film
+
+	   smpte431
+	       SMPTE-431
+
+	   smpte432
+	       SMPTE-432
+
+	   bt2020
+	       BT.2020
+
+	   jedec-p22
+	       JEDEC P22 phosphors
+
+       range
+	   Specify output color range.
+
+	   The accepted values are:
+
+	   tv  TV (restricted) range
+
+	   mpeg
+	       MPEG (restricted) range
+
+	   pc  PC (full) range
+
+	   jpeg
+	       JPEG (full) range
+
+       format
+	   Specify output color format.
+
+	   The accepted values are:
+
+	   yuv420p
+	       YUV 4:2:0 planar 8-bits
+
+	   yuv420p10
+	       YUV 4:2:0 planar 10-bits
+
+	   yuv420p12
+	       YUV 4:2:0 planar 12-bits
+
+	   yuv422p
+	       YUV 4:2:2 planar 8-bits
+
+	   yuv422p10
+	       YUV 4:2:2 planar 10-bits
+
+	   yuv422p12
+	       YUV 4:2:2 planar 12-bits
+
+	   yuv444p
+	       YUV 4:4:4 planar 8-bits
+
+	   yuv444p10
+	       YUV 4:4:4 planar 10-bits
+
+	   yuv444p12
+	       YUV 4:4:4 planar 12-bits
+
+       fast
+	   Do a fast conversion, which skips gamma/primary correction. This
+	   will take significantly less CPU, but will be mathematically
+	   incorrect. To get output compatible with that produced by the
+	   colormatrix filter, use fast=1.
+
+       dither
+	   Specify dithering mode.
+
+	   The accepted values are:
+
+	   none
+	       No dithering
+
+	   fsb Floyd-Steinberg dithering
+
+       wpadapt
+	   Whitepoint adaptation mode.
+
+	   The accepted values are:
+
+	   bradford
+	       Bradford whitepoint adaptation
+
+	   vonkries
+	       von Kries whitepoint adaptation
+
+	   identity
+	       identity whitepoint adaptation (i.e. no whitepoint adaptation)
+
+       iall
+	   Override all input properties at once. Same accepted values as all.
+
+       ispace
+	   Override input colorspace. Same accepted values as space.
+
+       iprimaries
+	   Override input color primaries. Same accepted values as primaries.
+
+       itrc
+	   Override input transfer characteristics. Same accepted values as
+	   trc.
+
+       irange
+	   Override input color range. Same accepted values as range.
+
+       The filter converts the transfer characteristics, color space and color
+       primaries to the specified user values. The output value, if not
+       specified, is set to a default value based on the "all" property. If
+       that property is also not specified, the filter will log an error. The
+       output color range and format default to the same value as the input
+       color range and format. The input transfer characteristics, color
+       space, color primaries and color range should be set on the input data.
+       If any of these are missing, the filter will log an error and no
+       conversion will take place.
+
+       For example to convert the input to SMPTE-240M, use the command:
+
+	       colorspace=smpte240m
+
+   colorspace_cuda
+       CUDA accelerated implementation of the colorspace filter.
+
+       It is by no means feature complete compared to the software colorspace
+       filter, and at the current time only supports color range conversion
+       between jpeg/full and mpeg/limited range.
+
+       The filter accepts the following options:
+
+       range
+	   Specify output color range.
+
+	   The accepted values are:
+
+	   tv  TV (restricted) range
+
+	   mpeg
+	       MPEG (restricted) range
+
+	   pc  PC (full) range
+
+	   jpeg
+	       JPEG (full) range
+
+   colortemperature
+       Adjust color temperature in video to simulate variations in ambient
+       color temperature.
+
+       The filter accepts the following options:
+
+       temperature
+	   Set the temperature in Kelvin. Allowed range is from 1000 to 40000.
+	   Default value is 6500 K.
+
+       mix Set mixing with filtered output. Allowed range is from 0 to 1.
+	   Default value is 1.
+
+       pl  Set the amount of preserving lightness. Allowed range is from 0 to
+	   1.  Default value is 0.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   convolution
+       Apply convolution of 3x3, 5x5, 7x7 or horizontal/vertical up to 49
+       elements.
+
+       The filter accepts the following options:
+
+       0m
+       1m
+       2m
+       3m  Set matrix for each plane.  Matrix is sequence of 9, 25 or 49
+	   signed integers in square mode, and from 1 to 49 odd number of
+	   signed integers in row mode.
+
+       0rdiv
+       1rdiv
+       2rdiv
+       3rdiv
+	   Set multiplier for calculated value for each plane.	If unset or 0,
+	   it will be sum of all matrix elements.
+
+       0bias
+       1bias
+       2bias
+       3bias
+	   Set bias for each plane. This value is added to the result of the
+	   multiplication.  Useful for making the overall image brighter or
+	   darker. Default is 0.0.
+
+       0mode
+       1mode
+       2mode
+       3mode
+	   Set matrix mode for each plane. Can be square, row or column.
+	   Default is square.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Apply sharpen:
+
+		   convolution="0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0"
+
+       o   Apply blur:
+
+		   convolution="1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9"
+
+       o   Apply edge enhance:
+
+		   convolution="0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128"
+
+       o   Apply edge detect:
+
+		   convolution="0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128"
+
+       o   Apply laplacian edge detector which includes diagonals:
+
+		   convolution="1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:5:5:5:1:0:128:128:0"
+
+       o   Apply emboss:
+
+		   convolution="-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2"
+
+   convolve
+       Apply 2D convolution of video stream in frequency domain using second
+       stream as impulse.
+
+       The filter accepts the following options:
+
+       planes
+	   Set which planes to process.
+
+       impulse
+	   Set which impulse video frames will be processed, can be first or
+	   all. Default is all.
+
+       The "convolve" filter also supports the framesync options.
+
+   copy
+       Copy the input video source unchanged to the output. This is mainly
+       useful for testing purposes.
+
+   coreimage
+       Video filtering on GPU using Apple's CoreImage API on OSX.
+
+       Hardware acceleration is based on an OpenGL context. Usually, this
+       means it is processed by video hardware. However, software-based OpenGL
+       implementations exist which means there is no guarantee for hardware
+       processing. It depends on the respective OSX.
+
+       There are many filters and image generators provided by Apple that come
+       with a large variety of options. The filter has to be referenced by its
+       name along with its options.
+
+       The coreimage filter accepts the following options:
+
+       list_filters
+	   List all available filters and generators along with all their
+	   respective options as well as possible minimum and maximum values
+	   along with the default values.
+
+		   list_filters=true
+
+       filter
+	   Specify all filters by their respective name and options.  Use
+	   list_filters to determine all valid filter names and options.
+	   Numerical options are specified by a float value and are
+	   automatically clamped to their respective value range.  Vector and
+	   color options have to be specified by a list of space separated
+	   float values. Character escaping has to be done.  A special option
+	   name "default" is available to use default options for a filter.
+
+	   It is required to specify either "default" or at least one of the
+	   filter options.  All omitted options are used with their default
+	   values.  The syntax of the filter string is as follows:
+
+		   filter=<NAME>@<OPTION>=<VALUE>[@<OPTION>=<VALUE>][@...][#<NAME>@<OPTION>=<VALUE>[@<OPTION>=<VALUE>][@...]][#...]
+
+       output_rect
+	   Specify a rectangle where the output of the filter chain is copied
+	   into the input image. It is given by a list of space separated
+	   float values:
+
+		   output_rect=x\ y\ width\ height
+
+	   If not given, the output rectangle equals the dimensions of the
+	   input image.  The output rectangle is automatically cropped at the
+	   borders of the input image. Negative values are valid for each
+	   component.
+
+		   output_rect=25\ 25\ 100\ 100
+
+       Several filters can be chained for successive processing without GPU-
+       HOST transfers allowing for fast processing of complex filter chains.
+       Currently, only filters with zero (generators) or exactly one (filters)
+       input image and one output image are supported. Also, transition
+       filters are not yet usable as intended.
+
+       Some filters generate output images with additional padding depending
+       on the respective filter kernel. The padding is automatically removed
+       to ensure the filter output has the same size as the input image.
+
+       For image generators, the size of the output image is determined by the
+       previous output image of the filter chain or the input image of the
+       whole filterchain, respectively. The generators do not use the pixel
+       information of this image to generate their output. However, the
+       generated output is blended onto this image, resulting in partial or
+       complete coverage of the output image.
+
+       The coreimagesrc video source can be used for generating input images
+       which are directly fed into the filter chain. By using it, providing
+       input images by another video source or an input video is not required.
+
+       Examples
+
+       o   List all filters available:
+
+		   coreimage=list_filters=true
+
+       o   Use the CIBoxBlur filter with default options to blur an image:
+
+		   coreimage=filter=CIBoxBlur@default
+
+       o   Use a filter chain with CISepiaTone at default values and
+	   CIVignetteEffect with its center at 100x100 and a radius of 50
+	   pixels:
+
+		   coreimage=filter=CIBoxBlur@default#CIVignetteEffect@inputCenter=100\ 100@inputRadius=50
+
+       o   Use nullsrc and CIQRCodeGenerator to create a QR code for the
+	   FFmpeg homepage, given as complete and escaped command-line for
+	   Apple's standard bash shell:
+
+		   ffmpeg -f lavfi -i nullsrc=s=100x100,coreimage=filter=CIQRCodeGenerator@inputMessage=https\\\\\://FFmpeg.org/@inputCorrectionLevel=H -frames:v 1 QRCode.png
+
+   corr
+       Obtain the correlation between two input videos.
+
+       This filter takes two input videos.
+
+       Both input videos must have the same resolution and pixel format for
+       this filter to work correctly. Also it assumes that both inputs have
+       the same number of frames, which are compared one by one.
+
+       The obtained per component, average, min and max correlation is printed
+       through the logging system.
+
+       The filter stores the calculated correlation of each frame in frame
+       metadata.
+
+       This filter also supports the framesync options.
+
+       In the below example the input file main.mpg being processed is
+       compared with the reference file ref.mpg.
+
+	       ffmpeg -i main.mpg -i ref.mpg -lavfi corr -f null -
+
+   cover_rect
+       Cover a rectangular object
+
+       It accepts the following options:
+
+       cover
+	   Filepath of the optional cover image, needs to be in yuv420.
+
+       mode
+	   Set covering mode.
+
+	   It accepts the following values:
+
+	   cover
+	       cover it by the supplied image
+
+	   blur
+	       cover it by interpolating the surrounding pixels
+
+	   Default value is blur.
+
+       Examples
+
+       o   Cover a rectangular object by the supplied image of a given video
+	   using ffmpeg:
+
+		   ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
+
+   crop
+       Crop the input video to given dimensions.
+
+       It accepts the following parameters:
+
+       w, out_w
+	   The width of the output video. It defaults to "iw".	This
+	   expression is evaluated only once during the filter configuration,
+	   or when the w or out_w command is sent.
+
+       h, out_h
+	   The height of the output video. It defaults to "ih".  This
+	   expression is evaluated only once during the filter configuration,
+	   or when the h or out_h command is sent.
+
+       x   The horizontal position, in the input video, of the left edge of
+	   the output video. It defaults to "(in_w-out_w)/2".  This expression
+	   is evaluated per-frame.
+
+       y   The vertical position, in the input video, of the top edge of the
+	   output video.  It defaults to "(in_h-out_h)/2".  This expression is
+	   evaluated per-frame.
+
+       keep_aspect
+	   If set to 1 will force the output display aspect ratio to be the
+	   same of the input, by changing the output sample aspect ratio. It
+	   defaults to 0.
+
+       exact
+	   Enable exact cropping. If enabled, subsampled videos will be
+	   cropped at exact width/height/x/y as specified and will not be
+	   rounded to nearest smaller value.  It defaults to 0.
+
+       The out_w, out_h, x, y parameters are expressions containing the
+       following constants:
+
+       x
+       y   The computed values for x and y. They are evaluated for each new
+	   frame.
+
+       in_w
+       in_h
+	   The input width and height.
+
+       iw
+       ih  These are the same as in_w and in_h.
+
+       out_w
+       out_h
+	   The output (cropped) width and height.
+
+       ow
+       oh  These are the same as out_w and out_h.
+
+       a   same as iw / ih
+
+       sar input sample aspect ratio
+
+       dar input display aspect ratio, it is the same as (iw / ih) * sar
+
+       hsub
+       vsub
+	   horizontal and vertical chroma subsample values. For example for
+	   the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       n   The number of the input frame, starting from 0.
+
+       pos the position in the file of the input frame, NAN if unknown
+
+       t   The timestamp expressed in seconds. It's NAN if the input timestamp
+	   is unknown.
+
+       The expression for out_w may depend on the value of out_h, and the
+       expression for out_h may depend on out_w, but they cannot depend on x
+       and y, as x and y are evaluated after out_w and out_h.
+
+       The x and y parameters specify the expressions for the position of the
+       top-left corner of the output (non-cropped) area. They are evaluated
+       for each frame. If the evaluated value is not valid, it is approximated
+       to the nearest valid value.
+
+       The expression for x may depend on y, and the expression for y may
+       depend on x.
+
+       Examples
+
+       o   Crop area with size 100x100 at position (12,34).
+
+		   crop=100:100:12:34
+
+	   Using named options, the example above becomes:
+
+		   crop=w=100:h=100:x=12:y=34
+
+       o   Crop the central input area with size 100x100:
+
+		   crop=100:100
+
+       o   Crop the central input area with size 2/3 of the input video:
+
+		   crop=2/3*in_w:2/3*in_h
+
+       o   Crop the input video central square:
+
+		   crop=out_w=in_h
+		   crop=in_h
+
+       o   Delimit the rectangle with the top-left corner placed at position
+	   100:100 and the right-bottom corner corresponding to the right-
+	   bottom corner of the input image.
+
+		   crop=in_w-100:in_h-100:100:100
+
+       o   Crop 10 pixels from the left and right borders, and 20 pixels from
+	   the top and bottom borders
+
+		   crop=in_w-2*10:in_h-2*20
+
+       o   Keep only the bottom right quarter of the input image:
+
+		   crop=in_w/2:in_h/2:in_w/2:in_h/2
+
+       o   Crop height for getting Greek harmony:
+
+		   crop=in_w:1/PHI*in_w
+
+       o   Apply trembling effect:
+
+		   crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)
+
+       o   Apply erratic camera effect depending on timestamp:
+
+		   crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
+
+       o   Set x depending on the value of y:
+
+		   crop=in_w/2:in_h/2:y:10+10*sin(n/10)
+
+       Commands
+
+       This filter supports the following commands:
+
+       w, out_w
+       h, out_h
+       x
+       y   Set width/height of the output video and the horizontal/vertical
+	   position in the input video.  The command accepts the same syntax
+	   of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   cropdetect
+       Auto-detect the crop size.
+
+       It calculates the necessary cropping parameters and prints the
+       recommended parameters via the logging system. The detected dimensions
+       correspond to the non-black or video area of the input video according
+       to mode.
+
+       It accepts the following parameters:
+
+       mode
+	   Depending on mode crop detection is based on either the mere black
+	   value of surrounding pixels or a combination of motion vectors and
+	   edge pixels.
+
+	   black
+	       Detect black pixels surrounding the playing video. For fine
+	       control use option limit.
+
+	   mvedges
+	       Detect the playing video by the motion vectors inside the video
+	       and scanning for edge pixels typically forming the border of a
+	       playing video.
+
+       limit
+	   Set higher black value threshold, which can be optionally specified
+	   from nothing (0) to everything (255 for 8-bit based formats). An
+	   intensity value greater to the set value is considered non-black.
+	   It defaults to 24.  You can also specify a value between 0.0 and
+	   1.0 which will be scaled depending on the bitdepth of the pixel
+	   format.
+
+       round
+	   The value which the width/height should be divisible by. It
+	   defaults to 16. The offset is automatically adjusted to center the
+	   video. Use 2 to get only even dimensions (needed for 4:2:2 video).
+	   16 is best when encoding to most video codecs.
+
+       skip
+	   Set the number of initial frames for which evaluation is skipped.
+	   Default is 2. Range is 0 to INT_MAX.
+
+       reset_count, reset
+	   Set the counter that determines after how many frames cropdetect
+	   will reset the previously detected largest video area and start
+	   over to detect the current optimal crop area. Default value is 0.
+
+	   This can be useful when channel logos distort the video area. 0
+	   indicates 'never reset', and returns the largest area encountered
+	   during playback.
+
+       mv_threshold
+	   Set motion in pixel units as threshold for motion detection. It
+	   defaults to 8.
+
+       low
+       high
+	   Set low and high threshold values used by the Canny thresholding
+	   algorithm.
+
+	   The high threshold selects the "strong" edge pixels, which are then
+	   connected through 8-connectivity with the "weak" edge pixels
+	   selected by the low threshold.
+
+	   low and high threshold values must be chosen in the range [0,1],
+	   and low should be lesser or equal to high.
+
+	   Default value for low is "5/255", and default value for high is
+	   "15/255".
+
+       Examples
+
+       o   Find video area surrounded by black borders:
+
+		   ffmpeg -i file.mp4 -vf cropdetect,metadata=mode=print -f null -
+
+       o   Find an embedded video area, generate motion vectors beforehand:
+
+		   ffmpeg -i file.mp4 -vf mestimate,cropdetect=mode=mvedges,metadata=mode=print -f null -
+
+       o   Find an embedded video area, use motion vectors from decoder:
+
+		   ffmpeg -flags2 +export_mvs -i file.mp4 -vf cropdetect=mode=mvedges,metadata=mode=print -f null -
+
+       Commands
+
+       This filter supports the following commands:
+
+       limit
+	   The command accepts the same syntax of the corresponding option.
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   cue
+       Delay video filtering until a given wallclock timestamp. The filter
+       first passes on preroll amount of frames, then it buffers at most
+       buffer amount of frames and waits for the cue. After reaching the cue
+       it forwards the buffered frames and also any subsequent frames coming
+       in its input.
+
+       The filter can be used synchronize the output of multiple ffmpeg
+       processes for realtime output devices like decklink. By putting the
+       delay in the filtering chain and pre-buffering frames the process can
+       pass on data to output almost immediately after the target wallclock
+       timestamp is reached.
+
+       Perfect frame accuracy cannot be guaranteed, but the result is good
+       enough for some use cases.
+
+       cue The cue timestamp expressed in a UNIX timestamp in microseconds.
+	   Default is 0.
+
+       preroll
+	   The duration of content to pass on as preroll expressed in seconds.
+	   Default is 0.
+
+       buffer
+	   The maximum duration of content to buffer before waiting for the
+	   cue expressed in seconds. Default is 0.
+
+   curves
+       Apply color adjustments using curves.
+
+       This filter is similar to the Adobe Photoshop and GIMP curves tools.
+       Each component (red, green and blue) has its values defined by N key
+       points tied from each other using a smooth curve. The x-axis represents
+       the pixel values from the input frame, and the y-axis the new pixel
+       values to be set for the output frame.
+
+       By default, a component curve is defined by the two points (0;0) and
+       (1;1). This creates a straight line where each original pixel value is
+       "adjusted" to its own value, which means no change to the image.
+
+       The filter allows you to redefine these two points and add some more. A
+       new curve will be define to pass smoothly through all these new
+       coordinates. The new defined points needs to be strictly increasing
+       over the x-axis, and their x and y values must be in the [0;1]
+       interval. The curve is formed by using a natural or monotonic cubic
+       spline interpolation, depending on the interp option (default:
+       "natural"). The "natural" spline produces a smoother curve in general
+       while the monotonic ("pchip") spline guarantees the transitions between
+       the specified points to be monotonic. If the computed curves happened
+       to go outside the vector spaces, the values will be clipped
+       accordingly.
+
+       The filter accepts the following options:
+
+       preset
+	   Select one of the available color presets. This option can be used
+	   in addition to the r, g, b parameters; in this case, the later
+	   options takes priority on the preset values.  Available presets
+	   are:
+
+	   none
+	   color_negative
+	   cross_process
+	   darker
+	   increase_contrast
+	   lighter
+	   linear_contrast
+	   medium_contrast
+	   negative
+	   strong_contrast
+	   vintage
+
+	   Default is "none".
+
+       master, m
+	   Set the master key points. These points will define a second pass
+	   mapping. It is sometimes called a "luminance" or "value" mapping.
+	   It can be used with r, g, b or all since it acts like a post-
+	   processing LUT.
+
+       red, r
+	   Set the key points for the red component.
+
+       green, g
+	   Set the key points for the green component.
+
+       blue, b
+	   Set the key points for the blue component.
+
+       all Set the key points for all components (not including master).  Can
+	   be used in addition to the other key points component options. In
+	   this case, the unset component(s) will fallback on this all
+	   setting.
+
+       psfile
+	   Specify a Photoshop curves file (".acv") to import the settings
+	   from.
+
+       plot
+	   Save Gnuplot script of the curves in specified file.
+
+       interp
+	   Specify the kind of interpolation. Available algorithms are:
+
+	   natural
+	       Natural cubic spline using a piece-wise cubic polynomial that
+	       is twice continuously differentiable.
+
+	   pchip
+	       Monotonic cubic spline using a piecewise cubic Hermite
+	       interpolating polynomial (PCHIP).
+
+       To avoid some filtergraph syntax conflicts, each key points list need
+       to be defined using the following syntax: "x0/y0 x1/y1 x2/y2 ...".
+
+       Commands
+
+       This filter supports same commands as options.
+
+       Examples
+
+       o   Increase slightly the middle level of blue:
+
+		   curves=blue='0/0 0.5/0.58 1/1'
+
+       o   Vintage effect:
+
+		   curves=r='0/0.11 .42/.51 1/0.95':g='0/0 0.50/0.48 1/1':b='0/0.22 .49/.44 1/0.8'
+
+	   Here we obtain the following coordinates for each components:
+
+	   red "(0;0.11) (0.42;0.51) (1;0.95)"
+
+	   green
+	       "(0;0) (0.50;0.48) (1;1)"
+
+	   blue
+	       "(0;0.22) (0.49;0.44) (1;0.80)"
+
+       o   The previous example can also be achieved with the associated
+	   built-in preset:
+
+		   curves=preset=vintage
+
+       o   Or simply:
+
+		   curves=vintage
+
+       o   Use a Photoshop preset and redefine the points of the green
+	   component:
+
+		   curves=psfile='MyCurvesPresets/purple.acv':green='0/0 0.45/0.53 1/1'
+
+       o   Check out the curves of the "cross_process" profile using ffmpeg
+	   and gnuplot:
+
+		   ffmpeg -f lavfi -i color -vf curves=cross_process:plot=/tmp/curves.plt -frames:v 1 -f null -
+		   gnuplot -p /tmp/curves.plt
+
+   datascope
+       Video data analysis filter.
+
+       This filter shows hexadecimal pixel values of part of video.
+
+       The filter accepts the following options:
+
+       size, s
+	   Set output video size.
+
+       x   Set x offset from where to pick pixels.
+
+       y   Set y offset from where to pick pixels.
+
+       mode
+	   Set scope mode, can be one of the following:
+
+	   mono
+	       Draw hexadecimal pixel values with white color on black
+	       background.
+
+	   color
+	       Draw hexadecimal pixel values with input video pixel color on
+	       black background.
+
+	   color2
+	       Draw hexadecimal pixel values on color background picked from
+	       input video, the text color is picked in such way so its always
+	       visible.
+
+       axis
+	   Draw rows and columns numbers on left and top of video.
+
+       opacity
+	   Set background opacity.
+
+       format
+	   Set display number format. Can be "hex", or "dec". Default is
+	   "hex".
+
+       components
+	   Set pixel components to display. By default all pixel components
+	   are displayed.
+
+       Commands
+
+       This filter supports same commands as options excluding "size" option.
+
+   dblur
+       Apply Directional blur filter.
+
+       The filter accepts the following options:
+
+       angle
+	   Set angle of directional blur. Default is 45.
+
+       radius
+	   Set radius of directional blur. Default is 5.
+
+       planes
+	   Set which planes to filter. By default all planes are filtered.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   dctdnoiz
+       Denoise frames using 2D DCT (frequency domain filtering).
+
+       This filter is not designed for real time.
+
+       The filter accepts the following options:
+
+       sigma, s
+	   Set the noise sigma constant.
+
+	   This sigma defines a hard threshold of "3 * sigma"; every DCT
+	   coefficient (absolute value) below this threshold with be dropped.
+
+	   If you need a more advanced filtering, see expr.
+
+	   Default is 0.
+
+       overlap
+	   Set number overlapping pixels for each block. Since the filter can
+	   be slow, you may want to reduce this value, at the cost of a less
+	   effective filter and the risk of various artefacts.
+
+	   If the overlapping value doesn't permit processing the whole input
+	   width or height, a warning will be displayed and according borders
+	   won't be denoised.
+
+	   Default value is blocksize-1, which is the best possible setting.
+
+       expr, e
+	   Set the coefficient factor expression.
+
+	   For each coefficient of a DCT block, this expression will be
+	   evaluated as a multiplier value for the coefficient.
+
+	   If this is option is set, the sigma option will be ignored.
+
+	   The absolute value of the coefficient can be accessed through the c
+	   variable.
+
+       n   Set the blocksize using the number of bits. "1<<n" defines the
+	   blocksize, which is the width and height of the processed blocks.
+
+	   The default value is 3 (8x8) and can be raised to 4 for a blocksize
+	   of 16x16. Note that changing this setting has huge consequences on
+	   the speed processing. Also, a larger block size does not
+	   necessarily means a better de-noising.
+
+       Examples
+
+       Apply a denoise with a sigma of 4.5:
+
+	       dctdnoiz=4.5
+
+       The same operation can be achieved using the expression system:
+
+	       dctdnoiz=e='gte(c, 4.5*3)'
+
+       Violent denoise using a block size of "16x16":
+
+	       dctdnoiz=15:n=4
+
+   deband
+       Remove banding artifacts from input video.  It works by replacing
+       banded pixels with average value of referenced pixels.
+
+       The filter accepts the following options:
+
+       1thr
+       2thr
+       3thr
+       4thr
+	   Set banding detection threshold for each plane. Default is 0.02.
+	   Valid range is 0.00003 to 0.5.  If difference between current pixel
+	   and reference pixel is less than threshold, it will be considered
+	   as banded.
+
+       range, r
+	   Banding detection range in pixels. Default is 16. If positive,
+	   random number in range 0 to set value will be used. If negative,
+	   exact absolute value will be used.  The range defines square of
+	   four pixels around current pixel.
+
+       direction, d
+	   Set direction in radians from which four pixel will be compared. If
+	   positive, random direction from 0 to set direction will be picked.
+	   If negative, exact of absolute value will be picked. For example
+	   direction 0, -PI or -2*PI radians will pick only pixels on same row
+	   and -PI/2 will pick only pixels on same column.
+
+       blur, b
+	   If enabled, current pixel is compared with average value of all
+	   four surrounding pixels. The default is enabled. If disabled
+	   current pixel is compared with all four surrounding pixels. The
+	   pixel is considered banded if only all four differences with
+	   surrounding pixels are less than threshold.
+
+       coupling, c
+	   If enabled, current pixel is changed if and only if all pixel
+	   components are banded, e.g. banding detection threshold is
+	   triggered for all color components.	The default is disabled.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   deblock
+       Remove blocking artifacts from input video.
+
+       The filter accepts the following options:
+
+       filter
+	   Set filter type, can be weak or strong. Default is strong.  This
+	   controls what kind of deblocking is applied.
+
+       block
+	   Set size of block, allowed range is from 4 to 512. Default is 8.
+
+       alpha
+       beta
+       gamma
+       delta
+	   Set blocking detection thresholds. Allowed range is 0 to 1.
+	   Defaults are: 0.098 for alpha and 0.05 for the rest.  Using higher
+	   threshold gives more deblocking strength.  Setting alpha controls
+	   threshold detection at exact edge of block.	Remaining options
+	   controls threshold detection near the edge. Each one for
+	   below/above or left/right. Setting any of those to 0 disables
+	   deblocking.
+
+       planes
+	   Set planes to filter. Default is to filter all available planes.
+
+       Examples
+
+       o   Deblock using weak filter and block size of 4 pixels.
+
+		   deblock=filter=weak:block=4
+
+       o   Deblock using strong filter, block size of 4 pixels and custom
+	   thresholds for deblocking more edges.
+
+		   deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05
+
+       o   Similar as above, but filter only first plane.
+
+		   deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=1
+
+       o   Similar as above, but filter only second and third plane.
+
+		   deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=6
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   decimate
+       Drop duplicated frames at regular intervals.
+
+       The filter accepts the following options:
+
+       cycle
+	   Set the number of frames from which one will be dropped. Setting
+	   this to N means one frame in every batch of N frames will be
+	   dropped.  Default is 5.
+
+       dupthresh
+	   Set the threshold for duplicate detection. If the difference metric
+	   for a frame is less than or equal to this value, then it is
+	   declared as duplicate. Default is 1.1
+
+       scthresh
+	   Set scene change threshold. Default is 15.
+
+       blockx
+       blocky
+	   Set the size of the x and y-axis blocks used during metric
+	   calculations.  Larger blocks give better noise suppression, but
+	   also give worse detection of small movements. Must be a power of
+	   two. Default is 32.
+
+       ppsrc
+	   Mark main input as a pre-processed input and activate clean source
+	   input stream. This allows the input to be pre-processed with
+	   various filters to help the metrics calculation while keeping the
+	   frame selection lossless. When set to 1, the first stream is for
+	   the pre-processed input, and the second stream is the clean source
+	   from where the kept frames are chosen. Default is 0.
+
+       chroma
+	   Set whether or not chroma is considered in the metric calculations.
+	   Default is 1.
+
+       mixed
+	   Set whether or not the input only partially contains content to be
+	   decimated.  Default is "false".  If enabled video output stream
+	   will be in variable frame rate.
+
+   deconvolve
+       Apply 2D deconvolution of video stream in frequency domain using second
+       stream as impulse.
+
+       The filter accepts the following options:
+
+       planes
+	   Set which planes to process.
+
+       impulse
+	   Set which impulse video frames will be processed, can be first or
+	   all. Default is all.
+
+       noise
+	   Set noise when doing divisions. Default is 0.0000001. Useful when
+	   width and height are not same and not power of 2 or if stream prior
+	   to convolving had noise.
+
+       The "deconvolve" filter also supports the framesync options.
+
+   dedot
+       Reduce cross-luminance (dot-crawl) and cross-color (rainbows) from
+       video.
+
+       It accepts the following options:
+
+       m   Set mode of operation. Can be combination of dotcrawl for cross-
+	   luminance reduction and/or rainbows for cross-color reduction.
+
+       lt  Set spatial luma threshold. Lower values increases reduction of
+	   cross-luminance.
+
+       tl  Set tolerance for temporal luma. Higher values increases reduction
+	   of cross-luminance.
+
+       tc  Set tolerance for chroma temporal variation. Higher values
+	   increases reduction of cross-color.
+
+       ct  Set temporal chroma threshold. Lower values increases reduction of
+	   cross-color.
+
+   deflate
+       Apply deflate effect to the video.
+
+       This filter replaces the pixel by the local(3x3) average by taking into
+       account only values lower than the pixel.
+
+       It accepts the following options:
+
+       threshold0
+       threshold1
+       threshold2
+       threshold3
+	   Limit the maximum change for each plane, default is 65535.  If 0,
+	   plane will remain unchanged.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   deflicker
+       Remove temporal frame luminance variations.
+
+       It accepts the following options:
+
+       size, s
+	   Set moving-average filter size in frames. Default is 5. Allowed
+	   range is 2 - 129.
+
+       mode, m
+	   Set averaging mode to smooth temporal luminance variations.
+
+	   Available values are:
+
+	   am  Arithmetic mean
+
+	   gm  Geometric mean
+
+	   hm  Harmonic mean
+
+	   qm  Quadratic mean
+
+	   cm  Cubic mean
+
+	   pm  Power mean
+
+	   median
+	       Median
+
+       bypass
+	   Do not actually modify frame. Useful when one only wants metadata.
+
+   dejudder
+       Remove judder produced by partially interlaced telecined content.
+
+       Judder can be introduced, for instance, by pullup filter. If the
+       original source was partially telecined content then the output of
+       "pullup,dejudder" will have a variable frame rate. May change the
+       recorded frame rate of the container. Aside from that change, this
+       filter will not affect constant frame rate video.
+
+       The option available in this filter is:
+
+       cycle
+	   Specify the length of the window over which the judder repeats.
+
+	   Accepts any integer greater than 1. Useful values are:
+
+	   4   If the original was telecined from 24 to 30 fps (Film to NTSC).
+
+	   5   If the original was telecined from 25 to 30 fps (PAL to NTSC).
+
+	   20  If a mixture of the two.
+
+	   The default is 4.
+
+   delogo
+       Suppress a TV station logo by a simple interpolation of the surrounding
+       pixels. Just set a rectangle covering the logo and watch it disappear
+       (and sometimes something even uglier appear - your mileage may vary).
+
+       It accepts the following parameters:
+
+       x
+       y   Specify the top left corner coordinates of the logo. They must be
+	   specified.
+
+       w
+       h   Specify the width and height of the logo to clear. They must be
+	   specified.
+
+       show
+	   When set to 1, a green rectangle is drawn on the screen to simplify
+	   finding the right x, y, w, and h parameters.  The default value is
+	   0.
+
+	   The rectangle is drawn on the outermost pixels which will be
+	   (partly) replaced with interpolated values. The values of the next
+	   pixels immediately outside this rectangle in each direction will be
+	   used to compute the interpolated pixel values inside the rectangle.
+
+       Examples
+
+       o   Set a rectangle covering the area with top left corner coordinates
+	   0,0 and size 100x77:
+
+		   delogo=x=0:y=0:w=100:h=77
+
+   derain
+       Remove the rain in the input image/video by applying the derain methods
+       based on convolutional neural networks. Supported models:
+
+       o   Recurrent Squeeze-and-Excitation Context Aggregation Net (RESCAN).
+	   See
+	   <http://openaccess.thecvf.com/content_ECCV_2018/papers/Xia_Li_Recurrent_Squeeze-and-Excitation_Context_ECCV_2018_paper.pdf>.
+
+       Training as well as model generation scripts are provided in the
+       repository at <https://github.com/XueweiMeng/derain_filter.git>.
+
+       Native model files (.model) can be generated from TensorFlow model
+       files (.pb) by using tools/python/convert.py
+
+       The filter accepts the following options:
+
+       filter_type
+	   Specify which filter to use. This option accepts the following
+	   values:
+
+	   derain
+	       Derain filter. To conduct derain filter, you need to use a
+	       derain model.
+
+	   dehaze
+	       Dehaze filter. To conduct dehaze filter, you need to use a
+	       dehaze model.
+
+	   Default value is derain.
+
+       dnn_backend
+	   Specify which DNN backend to use for model loading and execution.
+	   This option accepts the following values:
+
+	   native
+	       Native implementation of DNN loading and execution.
+
+	   tensorflow
+	       TensorFlow backend. To enable this backend you need to install
+	       the TensorFlow for C library (see
+	       <https://www.tensorflow.org/install/lang_c>) and configure
+	       FFmpeg with "--enable-libtensorflow"
+
+	   Default value is native.
+
+       model
+	   Set path to model file specifying network architecture and its
+	   parameters.	Note that different backends use different file
+	   formats. TensorFlow and native backend can load files for only its
+	   format.
+
+       To get full functionality (such as async execution), please use the
+       dnn_processing filter.
+
+   deshake
+       Attempt to fix small changes in horizontal and/or vertical shift. This
+       filter helps remove camera shake from hand-holding a camera, bumping a
+       tripod, moving on a vehicle, etc.
+
+       The filter accepts the following options:
+
+       x
+       y
+       w
+       h   Specify a rectangular area where to limit the search for motion
+	   vectors.  If desired the search for motion vectors can be limited
+	   to a rectangular area of the frame defined by its top left corner,
+	   width and height. These parameters have the same meaning as the
+	   drawbox filter which can be used to visualise the position of the
+	   bounding box.
+
+	   This is useful when simultaneous movement of subjects within the
+	   frame might be confused for camera motion by the motion vector
+	   search.
+
+	   If any or all of x, y, w and h are set to -1 then the full frame is
+	   used. This allows later options to be set without specifying the
+	   bounding box for the motion vector search.
+
+	   Default - search the whole frame.
+
+       rx
+       ry  Specify the maximum extent of movement in x and y directions in the
+	   range 0-64 pixels. Default 16.
+
+       edge
+	   Specify how to generate pixels to fill blanks at the edge of the
+	   frame. Available values are:
+
+	   blank, 0
+	       Fill zeroes at blank locations
+
+	   original, 1
+	       Original image at blank locations
+
+	   clamp, 2
+	       Extruded edge value at blank locations
+
+	   mirror, 3
+	       Mirrored edge at blank locations
+
+	   Default value is mirror.
+
+       blocksize
+	   Specify the blocksize to use for motion search. Range 4-128 pixels,
+	   default 8.
+
+       contrast
+	   Specify the contrast threshold for blocks. Only blocks with more
+	   than the specified contrast (difference between darkest and
+	   lightest pixels) will be considered. Range 1-255, default 125.
+
+       search
+	   Specify the search strategy. Available values are:
+
+	   exhaustive, 0
+	       Set exhaustive search
+
+	   less, 1
+	       Set less exhaustive search.
+
+	   Default value is exhaustive.
+
+       filename
+	   If set then a detailed log of the motion search is written to the
+	   specified file.
+
+   despill
+       Remove unwanted contamination of foreground colors, caused by reflected
+       color of greenscreen or bluescreen.
+
+       This filter accepts the following options:
+
+       type
+	   Set what type of despill to use.
+
+       mix Set how spillmap will be generated.
+
+       expand
+	   Set how much to get rid of still remaining spill.
+
+       red Controls amount of red in spill area.
+
+       green
+	   Controls amount of green in spill area.  Should be -1 for
+	   greenscreen.
+
+       blue
+	   Controls amount of blue in spill area.  Should be -1 for
+	   bluescreen.
+
+       brightness
+	   Controls brightness of spill area, preserving colors.
+
+       alpha
+	   Modify alpha from generated spillmap.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   detelecine
+       Apply an exact inverse of the telecine operation. It requires a
+       predefined pattern specified using the pattern option which must be the
+       same as that passed to the telecine filter.
+
+       This filter accepts the following options:
+
+       first_field
+	   top, t
+	       top field first
+
+	   bottom, b
+	       bottom field first The default value is "top".
+
+       pattern
+	   A string of numbers representing the pulldown pattern you wish to
+	   apply.  The default value is 23.
+
+       start_frame
+	   A number representing position of the first frame with respect to
+	   the telecine pattern. This is to be used if the stream is cut. The
+	   default value is 0.
+
+   dilation
+       Apply dilation effect to the video.
+
+       This filter replaces the pixel by the local(3x3) maximum.
+
+       It accepts the following options:
+
+       threshold0
+       threshold1
+       threshold2
+       threshold3
+	   Limit the maximum change for each plane, default is 65535.  If 0,
+	   plane will remain unchanged.
+
+       coordinates
+	   Flag which specifies the pixel to refer to. Default is 255 i.e. all
+	   eight pixels are used.
+
+	   Flags to local 3x3 coordinates maps like this:
+
+	       1 2 3
+	       4   5
+	       6 7 8
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   displace
+       Displace pixels as indicated by second and third input stream.
+
+       It takes three input streams and outputs one stream, the first input is
+       the source, and second and third input are displacement maps.
+
+       The second input specifies how much to displace pixels along the
+       x-axis, while the third input specifies how much to displace pixels
+       along the y-axis.  If one of displacement map streams terminates, last
+       frame from that displacement map will be used.
+
+       Note that once generated, displacements maps can be reused over and
+       over again.
+
+       A description of the accepted options follows.
+
+       edge
+	   Set displace behavior for pixels that are out of range.
+
+	   Available values are:
+
+	   blank
+	       Missing pixels are replaced by black pixels.
+
+	   smear
+	       Adjacent pixels will spread out to replace missing pixels.
+
+	   wrap
+	       Out of range pixels are wrapped so they point to pixels of
+	       other side.
+
+	   mirror
+	       Out of range pixels will be replaced with mirrored pixels.
+
+	   Default is smear.
+
+       Examples
+
+       o   Add ripple effect to rgb input of video size hd720:
+
+		   ffmpeg -i INPUT -f lavfi -i nullsrc=s=hd720,lutrgb=128:128:128 -f lavfi -i nullsrc=s=hd720,geq='r=128+30*sin(2*PI*X/400+T):g=128+30*sin(2*PI*X/400+T):b=128+30*sin(2*PI*X/400+T)' -lavfi '[0][1][2]displace' OUTPUT
+
+       o   Add wave effect to rgb input of video size hd720:
+
+		   ffmpeg -i INPUT -f lavfi -i nullsrc=hd720,geq='r=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):g=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):b=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T))' -lavfi '[1]split[x][y],[0][x][y]displace' OUTPUT
+
+   dnn_classify
+       Do classification with deep neural networks based on bounding boxes.
+
+       The filter accepts the following options:
+
+       dnn_backend
+	   Specify which DNN backend to use for model loading and execution.
+	   This option accepts only openvino now, tensorflow backends will be
+	   added.
+
+       model
+	   Set path to model file specifying network architecture and its
+	   parameters.	Note that different backends use different file
+	   formats.
+
+       input
+	   Set the input name of the dnn network.
+
+       output
+	   Set the output name of the dnn network.
+
+       confidence
+	   Set the confidence threshold (default: 0.5).
+
+       labels
+	   Set path to label file specifying the mapping between label id and
+	   name.  Each label name is written in one line, tailing spaces and
+	   empty lines are skipped.  The first line is the name of label id 0,
+	   and the second line is the name of label id 1, etc.	The label id
+	   is considered as name if the label file is not provided.
+
+       backend_configs
+	   Set the configs to be passed into backend
+
+	   For tensorflow backend, you can set its configs with sess_config
+	   options, please use tools/python/tf_sess_config.py to get the
+	   configs for your system.
+
+   dnn_detect
+       Do object detection with deep neural networks.
+
+       The filter accepts the following options:
+
+       dnn_backend
+	   Specify which DNN backend to use for model loading and execution.
+	   This option accepts only openvino now, tensorflow backends will be
+	   added.
+
+       model
+	   Set path to model file specifying network architecture and its
+	   parameters.	Note that different backends use different file
+	   formats.
+
+       input
+	   Set the input name of the dnn network.
+
+       output
+	   Set the output name of the dnn network.
+
+       confidence
+	   Set the confidence threshold (default: 0.5).
+
+       labels
+	   Set path to label file specifying the mapping between label id and
+	   name.  Each label name is written in one line, tailing spaces and
+	   empty lines are skipped.  The first line is the name of label id 0
+	   (usually it is 'background'), and the second line is the name of
+	   label id 1, etc.  The label id is considered as name if the label
+	   file is not provided.
+
+       backend_configs
+	   Set the configs to be passed into backend. To use async execution,
+	   set async (default: set).  Roll back to sync execution if the
+	   backend does not support async.
+
+   dnn_processing
+       Do image processing with deep neural networks. It works together with
+       another filter which converts the pixel format of the Frame to what the
+       dnn network requires.
+
+       The filter accepts the following options:
+
+       dnn_backend
+	   Specify which DNN backend to use for model loading and execution.
+	   This option accepts the following values:
+
+	   native
+	       Native implementation of DNN loading and execution.
+
+	   tensorflow
+	       TensorFlow backend. To enable this backend you need to install
+	       the TensorFlow for C library (see
+	       <https://www.tensorflow.org/install/lang_c>) and configure
+	       FFmpeg with "--enable-libtensorflow"
+
+	   openvino
+	       OpenVINO backend. To enable this backend you need to build and
+	       install the OpenVINO for C library (see
+	       <https://github.com/openvinotoolkit/openvino/blob/master/build-instruction.md>)
+	       and configure FFmpeg with "--enable-libopenvino"
+	       (--extra-cflags=-I... --extra-ldflags=-L... might be needed if
+	       the header files and libraries are not installed into system
+	       path)
+
+	   Default value is native.
+
+       model
+	   Set path to model file specifying network architecture and its
+	   parameters.	Note that different backends use different file
+	   formats. TensorFlow, OpenVINO and native backend can load files for
+	   only its format.
+
+	   Native model file (.model) can be generated from TensorFlow model
+	   file (.pb) by using tools/python/convert.py
+
+       input
+	   Set the input name of the dnn network.
+
+       output
+	   Set the output name of the dnn network.
+
+       backend_configs
+	   Set the configs to be passed into backend. To use async execution,
+	   set async (default: set).  Roll back to sync execution if the
+	   backend does not support async.
+
+	   For tensorflow backend, you can set its configs with sess_config
+	   options, please use tools/python/tf_sess_config.py to get the
+	   configs of TensorFlow backend for your system.
+
+       Examples
+
+       o   Remove rain in rgb24 frame with can.pb (see derain filter):
+
+		   ./ffmpeg -i rain.jpg -vf format=rgb24,dnn_processing=dnn_backend=tensorflow:model=can.pb:input=x:output=y derain.jpg
+
+       o   Halve the pixel value of the frame with format gray32f:
+
+		   ffmpeg -i input.jpg -vf format=grayf32,dnn_processing=model=halve_gray_float.model:input=dnn_in:output=dnn_out:dnn_backend=native -y out.native.png
+
+       o   Handle the Y channel with srcnn.pb (see sr filter) for frame with
+	   yuv420p (planar YUV formats supported):
+
+		   ./ffmpeg -i 480p.jpg -vf format=yuv420p,scale=w=iw*2:h=ih*2,dnn_processing=dnn_backend=tensorflow:model=srcnn.pb:input=x:output=y -y srcnn.jpg
+
+       o   Handle the Y channel with espcn.pb (see sr filter), which changes
+	   frame size, for format yuv420p (planar YUV formats supported),
+	   please use tools/python/tf_sess_config.py to get the configs of
+	   TensorFlow backend for your system.
+
+		   ./ffmpeg -i 480p.jpg -vf format=yuv420p,dnn_processing=dnn_backend=tensorflow:model=espcn.pb:input=x:output=y:backend_configs=sess_config=0x10022805320e09cdccccccccccec3f20012a01303801 -y tmp.espcn.jpg
+
+   drawbox
+       Draw a colored box on the input image.
+
+       It accepts the following parameters:
+
+       x
+       y   The expressions which specify the top left corner coordinates of
+	   the box. It defaults to 0.
+
+       width, w
+       height, h
+	   The expressions which specify the width and height of the box; if 0
+	   they are interpreted as the input width and height. It defaults to
+	   0.
+
+       color, c
+	   Specify the color of the box to write. For the general syntax of
+	   this option, check the "Color" section in the ffmpeg-utils manual.
+	   If the special value "invert" is used, the box edge color is the
+	   same as the video with inverted luma.
+
+       thickness, t
+	   The expression which sets the thickness of the box edge.  A value
+	   of "fill" will create a filled box. Default value is 3.
+
+	   See below for the list of accepted constants.
+
+       replace
+	   Applicable if the input has alpha. With value 1, the pixels of the
+	   painted box will overwrite the video's color and alpha pixels.
+	   Default is 0, which composites the box onto the input, leaving the
+	   video's alpha intact.
+
+       The parameters for x, y, w and h and t are expressions containing the
+       following constants:
+
+       dar The input display aspect ratio, it is the same as (w / h) * sar.
+
+       hsub
+       vsub
+	   horizontal and vertical chroma subsample values. For example for
+	   the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       in_h, ih
+       in_w, iw
+	   The input width and height.
+
+       sar The input sample aspect ratio.
+
+       x
+       y   The x and y offset coordinates where the box is drawn.
+
+       w
+       h   The width and height of the drawn box.
+
+       box_source
+	   Box source can be set as side_data_detection_bboxes if you want to
+	   use box data in detection bboxes of side data.
+
+	   If box_source is set, the x, y, width and height will be ignored
+	   and still use box data in detection bboxes of side data. So please
+	   do not use this parameter if you were not sure about the box
+	   source.
+
+       t   The thickness of the drawn box.
+
+	   These constants allow the x, y, w, h and t expressions to refer to
+	   each other, so you may for example specify "y=x/dar" or "h=w/dar".
+
+       Examples
+
+       o   Draw a black box around the edge of the input image:
+
+		   drawbox
+
+       o   Draw a box with color red and an opacity of 50%:
+
+		   drawbox=10:20:200:60:red@0.5
+
+	   The previous example can be specified as:
+
+		   drawbox=x=10:y=20:w=200:h=60:color=red@0.5
+
+       o   Fill the box with pink color:
+
+		   drawbox=x=10:y=10:w=100:h=100:color=pink@0.5:t=fill
+
+       o   Draw a 2-pixel red 2.40:1 mask:
+
+		   drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   drawgraph
+       Draw a graph using input video metadata.
+
+       It accepts the following parameters:
+
+       m1  Set 1st frame metadata key from which metadata values will be used
+	   to draw a graph.
+
+       fg1 Set 1st foreground color expression.
+
+       m2  Set 2nd frame metadata key from which metadata values will be used
+	   to draw a graph.
+
+       fg2 Set 2nd foreground color expression.
+
+       m3  Set 3rd frame metadata key from which metadata values will be used
+	   to draw a graph.
+
+       fg3 Set 3rd foreground color expression.
+
+       m4  Set 4th frame metadata key from which metadata values will be used
+	   to draw a graph.
+
+       fg4 Set 4th foreground color expression.
+
+       min Set minimal value of metadata value.
+
+       max Set maximal value of metadata value.
+
+       bg  Set graph background color. Default is white.
+
+       mode
+	   Set graph mode.
+
+	   Available values for mode is:
+
+	   bar
+	   dot
+	   line
+
+	   Default is "line".
+
+       slide
+	   Set slide mode.
+
+	   Available values for slide is:
+
+	   frame
+	       Draw new frame when right border is reached.
+
+	   replace
+	       Replace old columns with new ones.
+
+	   scroll
+	       Scroll from right to left.
+
+	   rscroll
+	       Scroll from left to right.
+
+	   picture
+	       Draw single picture.
+
+	   Default is "frame".
+
+       size
+	   Set size of graph video. For the syntax of this option, check the
+	   "Video size" section in the ffmpeg-utils manual.  The default value
+	   is "900x256".
+
+       rate, r
+	   Set the output frame rate. Default value is 25.
+
+	   The foreground color expressions can use the following variables:
+
+	   MIN Minimal value of metadata value.
+
+	   MAX Maximal value of metadata value.
+
+	   VAL Current metadata key value.
+
+	   The color is defined as 0xAABBGGRR.
+
+       Example using metadata from signalstats filter:
+
+	       signalstats,drawgraph=lavfi.signalstats.YAVG:min=0:max=255
+
+       Example using metadata from ebur128 filter:
+
+	       ebur128=metadata=1,adrawgraph=lavfi.r128.M:min=-120:max=5
+
+   drawgrid
+       Draw a grid on the input image.
+
+       It accepts the following parameters:
+
+       x
+       y   The expressions which specify the coordinates of some point of grid
+	   intersection (meant to configure offset). Both default to 0.
+
+       width, w
+       height, h
+	   The expressions which specify the width and height of the grid
+	   cell, if 0 they are interpreted as the input width and height,
+	   respectively, minus "thickness", so image gets framed. Default to
+	   0.
+
+       color, c
+	   Specify the color of the grid. For the general syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual. If
+	   the special value "invert" is used, the grid color is the same as
+	   the video with inverted luma.
+
+       thickness, t
+	   The expression which sets the thickness of the grid line. Default
+	   value is 1.
+
+	   See below for the list of accepted constants.
+
+       replace
+	   Applicable if the input has alpha. With 1 the pixels of the painted
+	   grid will overwrite the video's color and alpha pixels.  Default is
+	   0, which composites the grid onto the input, leaving the video's
+	   alpha intact.
+
+       The parameters for x, y, w and h and t are expressions containing the
+       following constants:
+
+       dar The input display aspect ratio, it is the same as (w / h) * sar.
+
+       hsub
+       vsub
+	   horizontal and vertical chroma subsample values. For example for
+	   the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       in_h, ih
+       in_w, iw
+	   The input grid cell width and height.
+
+       sar The input sample aspect ratio.
+
+       x
+       y   The x and y coordinates of some point of grid intersection (meant
+	   to configure offset).
+
+       w
+       h   The width and height of the drawn cell.
+
+       t   The thickness of the drawn cell.
+
+	   These constants allow the x, y, w, h and t expressions to refer to
+	   each other, so you may for example specify "y=x/dar" or "h=w/dar".
+
+       Examples
+
+       o   Draw a grid with cell 100x100 pixels, thickness 2 pixels, with
+	   color red and an opacity of 50%:
+
+		   drawgrid=width=100:height=100:thickness=2:color=red@0.5
+
+       o   Draw a white 3x3 grid with an opacity of 50%:
+
+		   drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   drawtext
+       Draw a text string or text from a specified file on top of a video,
+       using the libfreetype library.
+
+       To enable compilation of this filter, you need to configure FFmpeg with
+       "--enable-libfreetype".	To enable default font fallback and the font
+       option you need to configure FFmpeg with "--enable-libfontconfig".  To
+       enable the text_shaping option, you need to configure FFmpeg with
+       "--enable-libfribidi".
+
+       Syntax
+
+       It accepts the following parameters:
+
+       box Used to draw a box around text using the background color.  The
+	   value must be either 1 (enable) or 0 (disable).  The default value
+	   of box is 0.
+
+       boxborderw
+	   Set the width of the border to be drawn around the box using
+	   boxcolor.  The default value of boxborderw is 0.
+
+       boxcolor
+	   The color to be used for drawing box around text. For the syntax of
+	   this option, check the "Color" section in the ffmpeg-utils manual.
+
+	   The default value of boxcolor is "white".
+
+       line_spacing
+	   Set the line spacing in pixels of the border to be drawn around the
+	   box using box.  The default value of line_spacing is 0.
+
+       borderw
+	   Set the width of the border to be drawn around the text using
+	   bordercolor.  The default value of borderw is 0.
+
+       bordercolor
+	   Set the color to be used for drawing border around text. For the
+	   syntax of this option, check the "Color" section in the ffmpeg-
+	   utils manual.
+
+	   The default value of bordercolor is "black".
+
+       expansion
+	   Select how the text is expanded. Can be either "none", "strftime"
+	   (deprecated) or "normal" (default). See the drawtext_expansion,
+	   Text expansion section below for details.
+
+       basetime
+	   Set a start time for the count. Value is in microseconds. Only
+	   applied in the deprecated strftime expansion mode. To emulate in
+	   normal expansion mode use the "pts" function, supplying the start
+	   time (in seconds) as the second argument.
+
+       fix_bounds
+	   If true, check and fix text coords to avoid clipping.
+
+       fontcolor
+	   The color to be used for drawing fonts. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+
+	   The default value of fontcolor is "black".
+
+       fontcolor_expr
+	   String which is expanded the same way as text to obtain dynamic
+	   fontcolor value. By default this option has empty value and is not
+	   processed. When this option is set, it overrides fontcolor option.
+
+       font
+	   The font family to be used for drawing text. By default Sans.
+
+       fontfile
+	   The font file to be used for drawing text. The path must be
+	   included.  This parameter is mandatory if the fontconfig support is
+	   disabled.
+
+       alpha
+	   Draw the text applying alpha blending. The value can be a number
+	   between 0.0 and 1.0.  The expression accepts the same variables x,
+	   y as well.  The default value is 1.	Please see fontcolor_expr.
+
+       fontsize
+	   The font size to be used for drawing text.  The default value of
+	   fontsize is 16.
+
+       text_shaping
+	   If set to 1, attempt to shape the text (for example, reverse the
+	   order of right-to-left text and join Arabic characters) before
+	   drawing it.	Otherwise, just draw the text exactly as given.  By
+	   default 1 (if supported).
+
+       ft_load_flags
+	   The flags to be used for loading the fonts.
+
+	   The flags map the corresponding flags supported by libfreetype, and
+	   are a combination of the following values:
+
+	   default
+	   no_scale
+	   no_hinting
+	   render
+	   no_bitmap
+	   vertical_layout
+	   force_autohint
+	   crop_bitmap
+	   pedantic
+	   ignore_global_advance_width
+	   no_recurse
+	   ignore_transform
+	   monochrome
+	   linear_design
+	   no_autohint
+
+	   Default value is "default".
+
+	   For more information consult the documentation for the FT_LOAD_*
+	   libfreetype flags.
+
+       shadowcolor
+	   The color to be used for drawing a shadow behind the drawn text.
+	   For the syntax of this option, check the "Color" section in the
+	   ffmpeg-utils manual.
+
+	   The default value of shadowcolor is "black".
+
+       shadowx
+       shadowy
+	   The x and y offsets for the text shadow position with respect to
+	   the position of the text. They can be either positive or negative
+	   values. The default value for both is "0".
+
+       start_number
+	   The starting frame number for the n/frame_num variable. The default
+	   value is "0".
+
+       tabsize
+	   The size in number of spaces to use for rendering the tab.  Default
+	   value is 4.
+
+       timecode
+	   Set the initial timecode representation in "hh:mm:ss[:;.]ff"
+	   format. It can be used with or without text parameter.
+	   timecode_rate option must be specified.
+
+       timecode_rate, rate, r
+	   Set the timecode frame rate (timecode only). Value will be rounded
+	   to nearest integer. Minimum value is "1".  Drop-frame timecode is
+	   supported for frame rates 30 & 60.
+
+       tc24hmax
+	   If set to 1, the output of the timecode option will wrap around at
+	   24 hours.  Default is 0 (disabled).
+
+       text
+	   The text string to be drawn. The text must be a sequence of UTF-8
+	   encoded characters.	This parameter is mandatory if no file is
+	   specified with the parameter textfile.
+
+       textfile
+	   A text file containing text to be drawn. The text must be a
+	   sequence of UTF-8 encoded characters.
+
+	   This parameter is mandatory if no text string is specified with the
+	   parameter text.
+
+	   If both text and textfile are specified, an error is thrown.
+
+       text_source
+	   Text source should be set as side_data_detection_bboxes if you want
+	   to use text data in detection bboxes of side data.
+
+	   If text source is set, text and textfile will be ignored and still
+	   use text data in detection bboxes of side data. So please do not
+	   use this parameter if you are not sure about the text source.
+
+       reload
+	   The textfile will be reloaded at specified frame interval.  Be sure
+	   to update textfile atomically, or it may be read partially, or even
+	   fail.  Range is 0 to INT_MAX. Default is 0.
+
+       x
+       y   The expressions which specify the offsets where text will be drawn
+	   within the video frame. They are relative to the top/left border of
+	   the output image.
+
+	   The default value of x and y is "0".
+
+	   See below for the list of accepted constants and functions.
+
+       The parameters for x and y are expressions containing the following
+       constants and functions:
+
+       dar input display aspect ratio, it is the same as (w / h) * sar
+
+       hsub
+       vsub
+	   horizontal and vertical chroma subsample values. For example for
+	   the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       line_h, lh
+	   the height of each text line
+
+       main_h, h, H
+	   the input height
+
+       main_w, w, W
+	   the input width
+
+       max_glyph_a, ascent
+	   the maximum distance from the baseline to the highest/upper grid
+	   coordinate used to place a glyph outline point, for all the
+	   rendered glyphs.  It is a positive value, due to the grid's
+	   orientation with the Y axis upwards.
+
+       max_glyph_d, descent
+	   the maximum distance from the baseline to the lowest grid
+	   coordinate used to place a glyph outline point, for all the
+	   rendered glyphs.  This is a negative value, due to the grid's
+	   orientation, with the Y axis upwards.
+
+       max_glyph_h
+	   maximum glyph height, that is the maximum height for all the glyphs
+	   contained in the rendered text, it is equivalent to ascent -
+	   descent.
+
+       max_glyph_w
+	   maximum glyph width, that is the maximum width for all the glyphs
+	   contained in the rendered text
+
+       n   the number of input frame, starting from 0
+
+       rand(min, max)
+	   return a random number included between min and max
+
+       sar The input sample aspect ratio.
+
+       t   timestamp expressed in seconds, NAN if the input timestamp is
+	   unknown
+
+       text_h, th
+	   the height of the rendered text
+
+       text_w, tw
+	   the width of the rendered text
+
+       x
+       y   the x and y offset coordinates where the text is drawn.
+
+	   These parameters allow the x and y expressions to refer to each
+	   other, so you can for example specify "y=x/dar".
+
+       pict_type
+	   A one character description of the current frame's picture type.
+
+       pkt_pos
+	   The current packet's position in the input file or stream (in
+	   bytes, from the start of the input). A value of -1 indicates this
+	   info is not available.
+
+       duration
+	   The current packet's duration, in seconds.
+
+       pkt_size
+	   The current packet's size (in bytes).
+
+       Text expansion
+
+       If expansion is set to "strftime", the filter recognizes strftime()
+       sequences in the provided text and expands them accordingly. Check the
+       documentation of strftime(). This feature is deprecated.
+
+       If expansion is set to "none", the text is printed verbatim.
+
+       If expansion is set to "normal" (which is the default), the following
+       expansion mechanism is used.
+
+       The backslash character \, followed by any character, always expands to
+       the second character.
+
+       Sequences of the form "%{...}" are expanded. The text between the
+       braces is a function name, possibly followed by arguments separated by
+       ':'.  If the arguments contain special characters or delimiters (':' or
+       '}'), they should be escaped.
+
+       Note that they probably must also be escaped as the value for the text
+       option in the filter argument string and as the filter argument in the
+       filtergraph description, and possibly also for the shell, that makes up
+       to four levels of escaping; using a text file avoids these problems.
+
+       The following functions are available:
+
+       expr, e
+	   The expression evaluation result.
+
+	   It must take one argument specifying the expression to be
+	   evaluated, which accepts the same constants and functions as the x
+	   and y values. Note that not all constants should be used, for
+	   example the text size is not known when evaluating the expression,
+	   so the constants text_w and text_h will have an undefined value.
+
+       expr_int_format, eif
+	   Evaluate the expression's value and output as formatted integer.
+
+	   The first argument is the expression to be evaluated, just as for
+	   the expr function.  The second argument specifies the output
+	   format. Allowed values are x, X, d and u. They are treated exactly
+	   as in the "printf" function.  The third parameter is optional and
+	   sets the number of positions taken by the output.  It can be used
+	   to add padding with zeros from the left.
+
+       gmtime
+	   The time at which the filter is running, expressed in UTC.  It can
+	   accept an argument: a strftime() format string.  The format string
+	   is extended to support the variable %[1-6]N which prints fractions
+	   of the second with optionally specified number of digits.
+
+       localtime
+	   The time at which the filter is running, expressed in the local
+	   time zone.  It can accept an argument: a strftime() format string.
+	   The format string is extended to support the variable %[1-6]N which
+	   prints fractions of the second with optionally specified number of
+	   digits.
+
+       metadata
+	   Frame metadata. Takes one or two arguments.
+
+	   The first argument is mandatory and specifies the metadata key.
+
+	   The second argument is optional and specifies a default value, used
+	   when the metadata key is not found or empty.
+
+	   Available metadata can be identified by inspecting entries starting
+	   with TAG included within each frame section printed by running
+	   "ffprobe -show_frames".
+
+	   String metadata generated in filters leading to the drawtext filter
+	   are also available.
+
+       n, frame_num
+	   The frame number, starting from 0.
+
+       pict_type
+	   A one character description of the current picture type.
+
+       pts The timestamp of the current frame.	It can take up to three
+	   arguments.
+
+	   The first argument is the format of the timestamp; it defaults to
+	   "flt" for seconds as a decimal number with microsecond accuracy;
+	   "hms" stands for a formatted [-]HH:MM:SS.mmm timestamp with
+	   millisecond accuracy.  "gmtime" stands for the timestamp of the
+	   frame formatted as UTC time; "localtime" stands for the timestamp
+	   of the frame formatted as local time zone time.
+
+	   The second argument is an offset added to the timestamp.
+
+	   If the format is set to "hms", a third argument "24HH" may be
+	   supplied to present the hour part of the formatted timestamp in 24h
+	   format (00-23).
+
+	   If the format is set to "localtime" or "gmtime", a third argument
+	   may be supplied: a strftime() format string.  By default, YYYY-MM-
+	   DD HH:MM:SS format will be used.
+
+       Commands
+
+       This filter supports altering parameters via commands:
+
+       reinit
+	   Alter existing filter parameters.
+
+	   Syntax for the argument is the same as for filter invocation, e.g.
+
+		   fontsize=56:fontcolor=green:text='Hello World'
+
+	   Full filter invocation with sendcmd would look like this:
+
+		   sendcmd=c='56.0 drawtext reinit fontsize=56\:fontcolor=green\:text=Hello\\ World'
+
+       If the entire argument can't be parsed or applied as valid values then
+       the filter will continue with its existing parameters.
+
+       Examples
+
+       o   Draw "Test Text" with font FreeSerif, using the default values for
+	   the optional parameters.
+
+		   drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
+
+       o   Draw 'Test Text' with font FreeSerif of size 24 at position x=100
+	   and y=50 (counting from the top-left corner of the screen), text is
+	   yellow with a red box around it. Both the text and the box have an
+	   opacity of 20%.
+
+		   drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
+			     x=100: y=50: fontsize=24: fontcolor=yellow@0.2: box=1: boxcolor=red@0.2"
+
+	   Note that the double quotes are not necessary if spaces are not
+	   used within the parameter list.
+
+       o   Show the text at the center of the video frame:
+
+		   drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h)/2"
+
+       o   Show the text at a random position, switching to a new position
+	   every 30 seconds:
+
+		   drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=if(eq(mod(t\,30)\,0)\,rand(0\,(w-text_w))\,x):y=if(eq(mod(t\,30)\,0)\,rand(0\,(h-text_h))\,y)"
+
+       o   Show a text line sliding from right to left in the last row of the
+	   video frame. The file LONG_LINE is assumed to contain a single line
+	   with no newlines.
+
+		   drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"
+
+       o   Show the content of file CREDITS off the bottom of the frame and
+	   scroll up.
+
+		   drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
+
+       o   Draw a single green letter "g", at the center of the input video.
+	   The glyph baseline is placed at half screen height.
+
+		   drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"
+
+       o   Show text for 1 second every 3 seconds:
+
+		   drawtext="fontfile=FreeSerif.ttf:fontcolor=white:x=100:y=x/dar:enable=lt(mod(t\,3)\,1):text='blink'"
+
+       o   Use fontconfig to set the font. Note that the colons need to be
+	   escaped.
+
+		   drawtext='fontfile=Linux Libertine O-40\:style=Semibold:text=FFmpeg'
+
+       o   Draw "Test Text" with font size dependent on height of the video.
+
+		   drawtext="text='Test Text': fontsize=h/30: x=(w-text_w)/2: y=(h-text_h*2)"
+
+       o   Print the date of a real-time encoding (see strftime(3)):
+
+		   drawtext='fontfile=FreeSans.ttf:text=%{localtime\:%a %b %d %Y}'
+
+       o   Show text fading in and out (appearing/disappearing):
+
+		   #!/bin/sh
+		   DS=1.0 # display start
+		   DE=10.0 # display end
+		   FID=1.5 # fade in duration
+		   FOD=5 # fade out duration
+		   ffplay -f lavfi "color,drawtext=text=TEST:fontsize=50:fontfile=FreeSerif.ttf:fontcolor_expr=ff0000%{eif\\\\: clip(255*(1*between(t\\, $DS + $FID\\, $DE - $FOD) + ((t - $DS)/$FID)*between(t\\, $DS\\, $DS + $FID) + (-(t - $DE)/$FOD)*between(t\\, $DE - $FOD\\, $DE) )\\, 0\\, 255) \\\\: x\\\\: 2 }"
+
+       o   Horizontally align multiple separate texts. Note that max_glyph_a
+	   and the fontsize value are included in the y offset.
+
+		   drawtext=fontfile=FreeSans.ttf:text=DOG:fontsize=24:x=10:y=20+24-max_glyph_a,
+		   drawtext=fontfile=FreeSans.ttf:text=cow:fontsize=24:x=80:y=20+24-max_glyph_a
+
+       o   Plot special lavf.image2dec.source_basename metadata onto each
+	   frame if such metadata exists. Otherwise, plot the string "NA".
+	   Note that image2 demuxer must have option -export_path_metadata 1
+	   for the special metadata fields to be available for filters.
+
+		   drawtext="fontsize=20:fontcolor=white:fontfile=FreeSans.ttf:text='%{metadata\:lavf.image2dec.source_basename\:NA}':x=10:y=10"
+
+       For more information about libfreetype, check:
+       <http://www.freetype.org/>.
+
+       For more information about fontconfig, check:
+       <http://freedesktop.org/software/fontconfig/fontconfig-user.html>.
+
+       For more information about libfribidi, check: <http://fribidi.org/>.
+
+   edgedetect
+       Detect and draw edges. The filter uses the Canny Edge Detection
+       algorithm.
+
+       The filter accepts the following options:
+
+       low
+       high
+	   Set low and high threshold values used by the Canny thresholding
+	   algorithm.
+
+	   The high threshold selects the "strong" edge pixels, which are then
+	   connected through 8-connectivity with the "weak" edge pixels
+	   selected by the low threshold.
+
+	   low and high threshold values must be chosen in the range [0,1],
+	   and low should be lesser or equal to high.
+
+	   Default value for low is "20/255", and default value for high is
+	   "50/255".
+
+       mode
+	   Define the drawing mode.
+
+	   wires
+	       Draw white/gray wires on black background.
+
+	   colormix
+	       Mix the colors to create a paint/cartoon effect.
+
+	   canny
+	       Apply Canny edge detector on all selected planes.
+
+	   Default value is wires.
+
+       planes
+	   Select planes for filtering. By default all available planes are
+	   filtered.
+
+       Examples
+
+       o   Standard edge detection with custom values for the hysteresis
+	   thresholding:
+
+		   edgedetect=low=0.1:high=0.4
+
+       o   Painting effect without thresholding:
+
+		   edgedetect=mode=colormix:high=0
+
+   elbg
+       Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
+
+       For each input image, the filter will compute the optimal mapping from
+       the input to the output given the codebook length, that is the number
+       of distinct output colors.
+
+       This filter accepts the following options.
+
+       codebook_length, l
+	   Set codebook length. The value must be a positive integer, and
+	   represents the number of distinct output colors. Default value is
+	   256.
+
+       nb_steps, n
+	   Set the maximum number of iterations to apply for computing the
+	   optimal mapping. The higher the value the better the result and the
+	   higher the computation time. Default value is 1.
+
+       seed, s
+	   Set a random seed, must be an integer included between 0 and
+	   UINT32_MAX. If not specified, or if explicitly set to -1, the
+	   filter will try to use a good random seed on a best effort basis.
+
+       pal8
+	   Set pal8 output pixel format. This option does not work with
+	   codebook length greater than 256. Default is disabled.
+
+       use_alpha
+	   Include alpha values in the quantization calculation. Allows
+	   creating palettized output images (e.g. PNG8) with multiple alpha
+	   smooth blending.
+
+   entropy
+       Measure graylevel entropy in histogram of color channels of video
+       frames.
+
+       It accepts the following parameters:
+
+       mode
+	   Can be either normal or diff. Default is normal.
+
+	   diff mode measures entropy of histogram delta values, absolute
+	   differences between neighbour histogram values.
+
+   epx
+       Apply the EPX magnification filter which is designed for pixel art.
+
+       It accepts the following option:
+
+       n   Set the scaling dimension: 2 for "2xEPX", 3 for "3xEPX".  Default
+	   is 3.
+
+   eq
+       Set brightness, contrast, saturation and approximate gamma adjustment.
+
+       The filter accepts the following options:
+
+       contrast
+	   Set the contrast expression. The value must be a float value in
+	   range "-1000.0" to 1000.0. The default value is "1".
+
+       brightness
+	   Set the brightness expression. The value must be a float value in
+	   range "-1.0" to 1.0. The default value is "0".
+
+       saturation
+	   Set the saturation expression. The value must be a float in range
+	   0.0 to 3.0. The default value is "1".
+
+       gamma
+	   Set the gamma expression. The value must be a float in range 0.1 to
+	   10.0.  The default value is "1".
+
+       gamma_r
+	   Set the gamma expression for red. The value must be a float in
+	   range 0.1 to 10.0. The default value is "1".
+
+       gamma_g
+	   Set the gamma expression for green. The value must be a float in
+	   range 0.1 to 10.0. The default value is "1".
+
+       gamma_b
+	   Set the gamma expression for blue. The value must be a float in
+	   range 0.1 to 10.0. The default value is "1".
+
+       gamma_weight
+	   Set the gamma weight expression. It can be used to reduce the
+	   effect of a high gamma value on bright image areas, e.g. keep them
+	   from getting overamplified and just plain white. The value must be
+	   a float in range 0.0 to 1.0. A value of 0.0 turns the gamma
+	   correction all the way down while 1.0 leaves it at its full
+	   strength. Default is "1".
+
+       eval
+	   Set when the expressions for brightness, contrast, saturation and
+	   gamma expressions are evaluated.
+
+	   It accepts the following values:
+
+	   init
+	       only evaluate expressions once during the filter initialization
+	       or when a command is processed
+
+	   frame
+	       evaluate expressions for each incoming frame
+
+	   Default value is init.
+
+       The expressions accept the following parameters:
+
+       n   frame count of the input frame starting from 0
+
+       pos byte position of the corresponding packet in the input file, NAN if
+	   unspecified
+
+       r   frame rate of the input video, NAN if the input frame rate is
+	   unknown
+
+       t   timestamp expressed in seconds, NAN if the input timestamp is
+	   unknown
+
+       Commands
+
+       The filter supports the following commands:
+
+       contrast
+	   Set the contrast expression.
+
+       brightness
+	   Set the brightness expression.
+
+       saturation
+	   Set the saturation expression.
+
+       gamma
+	   Set the gamma expression.
+
+       gamma_r
+	   Set the gamma_r expression.
+
+       gamma_g
+	   Set gamma_g expression.
+
+       gamma_b
+	   Set gamma_b expression.
+
+       gamma_weight
+	   Set gamma_weight expression.
+
+	   The command accepts the same syntax of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   erosion
+       Apply erosion effect to the video.
+
+       This filter replaces the pixel by the local(3x3) minimum.
+
+       It accepts the following options:
+
+       threshold0
+       threshold1
+       threshold2
+       threshold3
+	   Limit the maximum change for each plane, default is 65535.  If 0,
+	   plane will remain unchanged.
+
+       coordinates
+	   Flag which specifies the pixel to refer to. Default is 255 i.e. all
+	   eight pixels are used.
+
+	   Flags to local 3x3 coordinates maps like this:
+
+	       1 2 3
+	       4   5
+	       6 7 8
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   estdif
+       Deinterlace the input video ("estdif" stands for "Edge Slope Tracing
+       Deinterlacing Filter").
+
+       Spatial only filter that uses edge slope tracing algorithm to
+       interpolate missing lines.  It accepts the following parameters:
+
+       mode
+	   The interlacing mode to adopt. It accepts one of the following
+	   values:
+
+	   frame
+	       Output one frame for each frame.
+
+	   field
+	       Output one frame for each field.
+
+	   The default value is "field".
+
+       parity
+	   The picture field parity assumed for the input interlaced video. It
+	   accepts one of the following values:
+
+	   tff Assume the top field is first.
+
+	   bff Assume the bottom field is first.
+
+	   auto
+	       Enable automatic detection of field parity.
+
+	   The default value is "auto".  If the interlacing is unknown or the
+	   decoder does not export this information, top field first will be
+	   assumed.
+
+       deint
+	   Specify which frames to deinterlace. Accepts one of the following
+	   values:
+
+	   all Deinterlace all frames.
+
+	   interlaced
+	       Only deinterlace frames marked as interlaced.
+
+	   The default value is "all".
+
+       rslope
+	   Specify the search radius for edge slope tracing. Default value is
+	   1.  Allowed range is from 1 to 15.
+
+       redge
+	   Specify the search radius for best edge matching. Default value is
+	   2.  Allowed range is from 0 to 15.
+
+       ecost
+	   Specify the edge cost for edge matching. Default value is 1.0.
+	   Allowed range is from 0 to 9.
+
+       mcost
+	   Specify the middle cost for edge matching. Default value is 0.5.
+	   Allowed range is from 0 to 1.
+
+       dcost
+	   Specify the distance cost for edge matching. Default value is 0.5.
+	   Allowed range is from 0 to 1.
+
+       interp
+	   Specify the interpolation used. Default is 4-point interpolation.
+	   It accepts one of the following values:
+
+	   2p  Two-point interpolation.
+
+	   4p  Four-point interpolation.
+
+	   6p  Six-point interpolation.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   exposure
+       Adjust exposure of the video stream.
+
+       The filter accepts the following options:
+
+       exposure
+	   Set the exposure correction in EV. Allowed range is from -3.0 to
+	   3.0 EV Default value is 0 EV.
+
+       black
+	   Set the black level correction. Allowed range is from -1.0 to 1.0.
+	   Default value is 0.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   extractplanes
+       Extract color channel components from input video stream into separate
+       grayscale video streams.
+
+       The filter accepts the following option:
+
+       planes
+	   Set plane(s) to extract.
+
+	   Available values for planes are:
+
+	   y
+	   u
+	   v
+	   a
+	   r
+	   g
+	   b
+
+	   Choosing planes not available in the input will result in an error.
+	   That means you cannot select "r", "g", "b" planes with "y", "u",
+	   "v" planes at same time.
+
+       Examples
+
+       o   Extract luma, u and v color channel component from input video
+	   frame into 3 grayscale outputs:
+
+		   ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
+
+   fade
+       Apply a fade-in/out effect to the input video.
+
+       It accepts the following parameters:
+
+       type, t
+	   The effect type can be either "in" for a fade-in, or "out" for a
+	   fade-out effect.  Default is "in".
+
+       start_frame, s
+	   Specify the number of the frame to start applying the fade effect
+	   at. Default is 0.
+
+       nb_frames, n
+	   The number of frames that the fade effect lasts. At the end of the
+	   fade-in effect, the output video will have the same intensity as
+	   the input video.  At the end of the fade-out transition, the output
+	   video will be filled with the selected color.  Default is 25.
+
+       alpha
+	   If set to 1, fade only alpha channel, if one exists on the input.
+	   Default value is 0.
+
+       start_time, st
+	   Specify the timestamp (in seconds) of the frame to start to apply
+	   the fade effect. If both start_frame and start_time are specified,
+	   the fade will start at whichever comes last.  Default is 0.
+
+       duration, d
+	   The number of seconds for which the fade effect has to last. At the
+	   end of the fade-in effect the output video will have the same
+	   intensity as the input video, at the end of the fade-out transition
+	   the output video will be filled with the selected color.  If both
+	   duration and nb_frames are specified, duration is used. Default is
+	   0 (nb_frames is used by default).
+
+       color, c
+	   Specify the color of the fade. Default is "black".
+
+       Examples
+
+       o   Fade in the first 30 frames of video:
+
+		   fade=in:0:30
+
+	   The command above is equivalent to:
+
+		   fade=t=in:s=0:n=30
+
+       o   Fade out the last 45 frames of a 200-frame video:
+
+		   fade=out:155:45
+		   fade=type=out:start_frame=155:nb_frames=45
+
+       o   Fade in the first 25 frames and fade out the last 25 frames of a
+	   1000-frame video:
+
+		   fade=in:0:25, fade=out:975:25
+
+       o   Make the first 5 frames yellow, then fade in from frame 5-24:
+
+		   fade=in:5:20:color=yellow
+
+       o   Fade in alpha over first 25 frames of video:
+
+		   fade=in:0:25:alpha=1
+
+       o   Make the first 5.5 seconds black, then fade in for 0.5 seconds:
+
+		   fade=t=in:st=5.5:d=0.5
+
+   feedback
+       Apply feedback video filter.
+
+       This filter pass cropped input frames to 2nd output.  From there it can
+       be filtered with other video filters.  After filter receives frame from
+       2nd input, that frame is combined on top of original frame from 1st
+       input and passed to 1st output.
+
+       The typical usage is filter only part of frame.
+
+       The filter accepts the following options:
+
+       x
+       y   Set the top left crop position.
+
+       w
+       h   Set the crop size.
+
+       Examples
+
+       o   Blur only top left rectangular part of video frame size 100x100
+	   with gblur filter.
+
+		   [in][blurin]feedback=x=0:y=0:w=100:h=100[out][blurout];[blurout]gblur=8[blurin]
+
+       o   Draw black box on top left part of video frame of size 100x100 with
+	   drawbox filter.
+
+		   [in][blurin]feedback=x=0:y=0:w=100:h=100[out][blurout];[blurout]drawbox=x=0:y=0:w=100:h=100:t=100[blurin]
+
+   fftdnoiz
+       Denoise frames using 3D FFT (frequency domain filtering).
+
+       The filter accepts the following options:
+
+       sigma
+	   Set the noise sigma constant. This sets denoising strength.
+	   Default value is 1. Allowed range is from 0 to 30.  Using very high
+	   sigma with low overlap may give blocking artifacts.
+
+       amount
+	   Set amount of denoising. By default all detected noise is reduced.
+	   Default value is 1. Allowed range is from 0 to 1.
+
+       block
+	   Set size of block in pixels, Default is 32, can be 8 to 256.
+
+       overlap
+	   Set block overlap. Default is 0.5. Allowed range is from 0.2 to
+	   0.8.
+
+       method
+	   Set denoising method. Default is "wiener", can also be "hard".
+
+       prev
+	   Set number of previous frames to use for denoising. By default is
+	   set to 0.
+
+       next
+	   Set number of next frames to to use for denoising. By default is
+	   set to 0.
+
+       planes
+	   Set planes which will be filtered, by default are all available
+	   filtered except alpha.
+
+   fftfilt
+       Apply arbitrary expressions to samples in frequency domain
+
+       dc_Y
+	   Adjust the dc value (gain) of the luma plane of the image. The
+	   filter accepts an integer value in range 0 to 1000. The default
+	   value is set to 0.
+
+       dc_U
+	   Adjust the dc value (gain) of the 1st chroma plane of the image.
+	   The filter accepts an integer value in range 0 to 1000. The default
+	   value is set to 0.
+
+       dc_V
+	   Adjust the dc value (gain) of the 2nd chroma plane of the image.
+	   The filter accepts an integer value in range 0 to 1000. The default
+	   value is set to 0.
+
+       weight_Y
+	   Set the frequency domain weight expression for the luma plane.
+
+       weight_U
+	   Set the frequency domain weight expression for the 1st chroma
+	   plane.
+
+       weight_V
+	   Set the frequency domain weight expression for the 2nd chroma
+	   plane.
+
+       eval
+	   Set when the expressions are evaluated.
+
+	   It accepts the following values:
+
+	   init
+	       Only evaluate expressions once during the filter
+	       initialization.
+
+	   frame
+	       Evaluate expressions for each incoming frame.
+
+	   Default value is init.
+
+	   The filter accepts the following variables:
+
+       X
+       Y   The coordinates of the current sample.
+
+       W
+       H   The width and height of the image.
+
+       N   The number of input frame, starting from 0.
+
+       WS
+       HS  The size of FFT array for horizontal and vertical processing.
+
+       Examples
+
+       o   High-pass:
+
+		   fftfilt=dc_Y=128:weight_Y='squish(1-(Y+X)/100)'
+
+       o   Low-pass:
+
+		   fftfilt=dc_Y=0:weight_Y='squish((Y+X)/100-1)'
+
+       o   Sharpen:
+
+		   fftfilt=dc_Y=0:weight_Y='1+squish(1-(Y+X)/100)'
+
+       o   Blur:
+
+		   fftfilt=dc_Y=0:weight_Y='exp(-4 * ((Y+X)/(W+H)))'
+
+   field
+       Extract a single field from an interlaced image using stride arithmetic
+       to avoid wasting CPU time. The output frames are marked as non-
+       interlaced.
+
+       The filter accepts the following options:
+
+       type
+	   Specify whether to extract the top (if the value is 0 or "top") or
+	   the bottom field (if the value is 1 or "bottom").
+
+   fieldhint
+       Create new frames by copying the top and bottom fields from surrounding
+       frames supplied as numbers by the hint file.
+
+       hint
+	   Set file containing hints: absolute/relative frame numbers.
+
+	   There must be one line for each frame in a clip. Each line must
+	   contain two numbers separated by the comma, optionally followed by
+	   "-" or "+".	Numbers supplied on each line of file can not be out
+	   of [N-1,N+1] where N is current frame number for "absolute" mode or
+	   out of [-1, 1] range for "relative" mode. First number tells from
+	   which frame to pick up top field and second number tells from which
+	   frame to pick up bottom field.
+
+	   If optionally followed by "+" output frame will be marked as
+	   interlaced, else if followed by "-" output frame will be marked as
+	   progressive, else it will be marked same as input frame.  If
+	   optionally followed by "t" output frame will use only top field, or
+	   in case of "b" it will use only bottom field.  If line starts with
+	   "#" or ";" that line is skipped.
+
+       mode
+	   Can be item "absolute" or "relative" or "pattern". Default is
+	   "absolute".	The "pattern" mode is same as "relative" mode, except
+	   at last entry of file if there are more frames to process than
+	   "hint" file is seek back to start.
+
+       Example of first several lines of "hint" file for "relative" mode:
+
+	       0,0 - # first frame
+	       1,0 - # second frame, use third's frame top field and second's frame bottom field
+	       1,0 - # third frame, use fourth's frame top field and third's frame bottom field
+	       1,0 -
+	       0,0 -
+	       0,0 -
+	       1,0 -
+	       1,0 -
+	       1,0 -
+	       0,0 -
+	       0,0 -
+	       1,0 -
+	       1,0 -
+	       1,0 -
+	       0,0 -
+
+   fieldmatch
+       Field matching filter for inverse telecine. It is meant to reconstruct
+       the progressive frames from a telecined stream. The filter does not
+       drop duplicated frames, so to achieve a complete inverse telecine
+       "fieldmatch" needs to be followed by a decimation filter such as
+       decimate in the filtergraph.
+
+       The separation of the field matching and the decimation is notably
+       motivated by the possibility of inserting a de-interlacing filter
+       fallback between the two.  If the source has mixed telecined and real
+       interlaced content, "fieldmatch" will not be able to match fields for
+       the interlaced parts.  But these remaining combed frames will be marked
+       as interlaced, and thus can be de-interlaced by a later filter such as
+       yadif before decimation.
+
+       In addition to the various configuration options, "fieldmatch" can take
+       an optional second stream, activated through the ppsrc option. If
+       enabled, the frames reconstruction will be based on the fields and
+       frames from this second stream. This allows the first input to be pre-
+       processed in order to help the various algorithms of the filter, while
+       keeping the output lossless (assuming the fields are matched properly).
+       Typically, a field-aware denoiser, or brightness/contrast adjustments
+       can help.
+
+       Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth
+       project) and VIVTC/VFM (VapourSynth project). The later is a light
+       clone of TFM from which "fieldmatch" is based on. While the semantic
+       and usage are very close, some behaviour and options names can differ.
+
+       The decimate filter currently only works for constant frame rate input.
+       If your input has mixed telecined (30fps) and progressive content with
+       a lower framerate like 24fps use the following filterchain to produce
+       the necessary cfr stream:
+       "dejudder,fps=30000/1001,fieldmatch,decimate".
+
+       The filter accepts the following options:
+
+       order
+	   Specify the assumed field order of the input stream. Available
+	   values are:
+
+	   auto
+	       Auto detect parity (use FFmpeg's internal parity value).
+
+	   bff Assume bottom field first.
+
+	   tff Assume top field first.
+
+	   Note that it is sometimes recommended not to trust the parity
+	   announced by the stream.
+
+	   Default value is auto.
+
+       mode
+	   Set the matching mode or strategy to use. pc mode is the safest in
+	   the sense that it won't risk creating jerkiness due to duplicate
+	   frames when possible, but if there are bad edits or blended fields
+	   it will end up outputting combed frames when a good match might
+	   actually exist. On the other hand, pcn_ub mode is the most risky in
+	   terms of creating jerkiness, but will almost always find a good
+	   frame if there is one. The other values are all somewhere in
+	   between pc and pcn_ub in terms of risking jerkiness and creating
+	   duplicate frames versus finding good matches in sections with bad
+	   edits, orphaned fields, blended fields, etc.
+
+	   More details about p/c/n/u/b are available in p/c/n/u/b meaning
+	   section.
+
+	   Available values are:
+
+	   pc  2-way matching (p/c)
+
+	   pc_n
+	       2-way matching, and trying 3rd match if still combed (p/c + n)
+
+	   pc_u
+	       2-way matching, and trying 3rd match (same order) if still
+	       combed (p/c + u)
+
+	   pc_n_ub
+	       2-way matching, trying 3rd match if still combed, and trying
+	       4th/5th matches if still combed (p/c + n + u/b)
+
+	   pcn 3-way matching (p/c/n)
+
+	   pcn_ub
+	       3-way matching, and trying 4th/5th matches if all 3 of the
+	       original matches are detected as combed (p/c/n + u/b)
+
+	   The parenthesis at the end indicate the matches that would be used
+	   for that mode assuming order=tff (and field on auto or top).
+
+	   In terms of speed pc mode is by far the fastest and pcn_ub is the
+	   slowest.
+
+	   Default value is pc_n.
+
+       ppsrc
+	   Mark the main input stream as a pre-processed input, and enable the
+	   secondary input stream as the clean source to pick the fields from.
+	   See the filter introduction for more details. It is similar to the
+	   clip2 feature from VFM/TFM.
+
+	   Default value is 0 (disabled).
+
+       field
+	   Set the field to match from. It is recommended to set this to the
+	   same value as order unless you experience matching failures with
+	   that setting. In certain circumstances changing the field that is
+	   used to match from can have a large impact on matching performance.
+	   Available values are:
+
+	   auto
+	       Automatic (same value as order).
+
+	   bottom
+	       Match from the bottom field.
+
+	   top Match from the top field.
+
+	   Default value is auto.
+
+       mchroma
+	   Set whether or not chroma is included during the match comparisons.
+	   In most cases it is recommended to leave this enabled. You should
+	   set this to 0 only if your clip has bad chroma problems such as
+	   heavy rainbowing or other artifacts. Setting this to 0 could also
+	   be used to speed things up at the cost of some accuracy.
+
+	   Default value is 1.
+
+       y0
+       y1  These define an exclusion band which excludes the lines between y0
+	   and y1 from being included in the field matching decision. An
+	   exclusion band can be used to ignore subtitles, a logo, or other
+	   things that may interfere with the matching. y0 sets the starting
+	   scan line and y1 sets the ending line; all lines in between y0 and
+	   y1 (including y0 and y1) will be ignored. Setting y0 and y1 to the
+	   same value will disable the feature.  y0 and y1 defaults to 0.
+
+       scthresh
+	   Set the scene change detection threshold as a percentage of maximum
+	   change on the luma plane. Good values are in the "[8.0, 14.0]"
+	   range. Scene change detection is only relevant in case
+	   combmatch=sc.  The range for scthresh is "[0.0, 100.0]".
+
+	   Default value is 12.0.
+
+       combmatch
+	   When combatch is not none, "fieldmatch" will take into account the
+	   combed scores of matches when deciding what match to use as the
+	   final match. Available values are:
+
+	   none
+	       No final matching based on combed scores.
+
+	   sc  Combed scores are only used when a scene change is detected.
+
+	   full
+	       Use combed scores all the time.
+
+	   Default is sc.
+
+       combdbg
+	   Force "fieldmatch" to calculate the combed metrics for certain
+	   matches and print them. This setting is known as micout in TFM/VFM
+	   vocabulary.	Available values are:
+
+	   none
+	       No forced calculation.
+
+	   pcn Force p/c/n calculations.
+
+	   pcnub
+	       Force p/c/n/u/b calculations.
+
+	   Default value is none.
+
+       cthresh
+	   This is the area combing threshold used for combed frame detection.
+	   This essentially controls how "strong" or "visible" combing must be
+	   to be detected.  Larger values mean combing must be more visible
+	   and smaller values mean combing can be less visible or strong and
+	   still be detected. Valid settings are from "-1" (every pixel will
+	   be detected as combed) to 255 (no pixel will be detected as
+	   combed). This is basically a pixel difference value. A good range
+	   is "[8, 12]".
+
+	   Default value is 9.
+
+       chroma
+	   Sets whether or not chroma is considered in the combed frame
+	   decision.  Only disable this if your source has chroma problems
+	   (rainbowing, etc.) that are causing problems for the combed frame
+	   detection with chroma enabled. Actually, using chroma=0 is usually
+	   more reliable, except for the case where there is chroma only
+	   combing in the source.
+
+	   Default value is 0.
+
+       blockx
+       blocky
+	   Respectively set the x-axis and y-axis size of the window used
+	   during combed frame detection. This has to do with the size of the
+	   area in which combpel pixels are required to be detected as combed
+	   for a frame to be declared combed. See the combpel parameter
+	   description for more info.  Possible values are any number that is
+	   a power of 2 starting at 4 and going up to 512.
+
+	   Default value is 16.
+
+       combpel
+	   The number of combed pixels inside any of the blocky by blockx size
+	   blocks on the frame for the frame to be detected as combed. While
+	   cthresh controls how "visible" the combing must be, this setting
+	   controls "how much" combing there must be in any localized area (a
+	   window defined by the blockx and blocky settings) on the frame.
+	   Minimum value is 0 and maximum is "blocky x blockx" (at which point
+	   no frames will ever be detected as combed). This setting is known
+	   as MI in TFM/VFM vocabulary.
+
+	   Default value is 80.
+
+       p/c/n/u/b meaning
+
+       p/c/n
+
+       We assume the following telecined stream:
+
+	       Top fields:     1 2 2 3 4
+	       Bottom fields:  1 2 3 4 4
+
+       The numbers correspond to the progressive frame the fields relate to.
+       Here, the first two frames are progressive, the 3rd and 4th are combed,
+       and so on.
+
+       When "fieldmatch" is configured to run a matching from bottom
+       (field=bottom) this is how this input stream get transformed:
+
+	       Input stream:
+			       T     1 2 2 3 4
+			       B     1 2 3 4 4	 <-- matching reference
+
+	       Matches: 	     c c n n c
+
+	       Output stream:
+			       T     1 2 3 4 4
+			       B     1 2 3 4 4
+
+       As a result of the field matching, we can see that some frames get
+       duplicated.  To perform a complete inverse telecine, you need to rely
+       on a decimation filter after this operation. See for instance the
+       decimate filter.
+
+       The same operation now matching from top fields (field=top) looks like
+       this:
+
+	       Input stream:
+			       T     1 2 2 3 4	 <-- matching reference
+			       B     1 2 3 4 4
+
+	       Matches: 	     c c p p c
+
+	       Output stream:
+			       T     1 2 2 3 4
+			       B     1 2 2 3 4
+
+       In these examples, we can see what p, c and n mean; basically, they
+       refer to the frame and field of the opposite parity:
+
+       *<p matches the field of the opposite parity in the previous frame>
+       *<c matches the field of the opposite parity in the current frame>
+       *<n matches the field of the opposite parity in the next frame>
+
+       u/b
+
+       The u and b matching are a bit special in the sense that they match
+       from the opposite parity flag. In the following examples, we assume
+       that we are currently matching the 2nd frame (Top:2, bottom:2).
+       According to the match, a 'x' is placed above and below each matched
+       fields.
+
+       With bottom matching (field=bottom):
+
+	       Match:		c	  p	      n 	 b	    u
+
+				x	x		x	 x	    x
+		 Top	      1 2 2	1 2 2	    1 2 2      1 2 2	  1 2 2
+		 Bottom       1 2 3	1 2 3	    1 2 3      1 2 3	  1 2 3
+				x	  x	      x        x	      x
+
+	       Output frames:
+				2	   1	      2 	 2	    2
+				2	   2	      2 	 1	    3
+
+       With top matching (field=top):
+
+	       Match:		c	  p	      n 	 b	    u
+
+				x	  x	      x        x	      x
+		 Top	      1 2 2	1 2 2	    1 2 2      1 2 2	  1 2 2
+		 Bottom       1 2 3	1 2 3	    1 2 3      1 2 3	  1 2 3
+				x	x		x	 x	    x
+
+	       Output frames:
+				2	   2	      2 	 1	    2
+				2	   1	      3 	 2	    2
+
+       Examples
+
+       Simple IVTC of a top field first telecined stream:
+
+	       fieldmatch=order=tff:combmatch=none, decimate
+
+       Advanced IVTC, with fallback on yadif for still combed frames:
+
+	       fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
+
+   fieldorder
+       Transform the field order of the input video.
+
+       It accepts the following parameters:
+
+       order
+	   The output field order. Valid values are tff for top field first or
+	   bff for bottom field first.
+
+       The default value is tff.
+
+       The transformation is done by shifting the picture content up or down
+       by one line, and filling the remaining line with appropriate picture
+       content.  This method is consistent with most broadcast field order
+       converters.
+
+       If the input video is not flagged as being interlaced, or it is already
+       flagged as being of the required output field order, then this filter
+       does not alter the incoming video.
+
+       It is very useful when converting to or from PAL DV material, which is
+       bottom field first.
+
+       For example:
+
+	       ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
+
+   fifo, afifo
+       Buffer input images and send them when they are requested.
+
+       It is mainly useful when auto-inserted by the libavfilter framework.
+
+       It does not take parameters.
+
+   fillborders
+       Fill borders of the input video, without changing video stream
+       dimensions.  Sometimes video can have garbage at the four edges and you
+       may not want to crop video input to keep size multiple of some number.
+
+       This filter accepts the following options:
+
+       left
+	   Number of pixels to fill from left border.
+
+       right
+	   Number of pixels to fill from right border.
+
+       top Number of pixels to fill from top border.
+
+       bottom
+	   Number of pixels to fill from bottom border.
+
+       mode
+	   Set fill mode.
+
+	   It accepts the following values:
+
+	   smear
+	       fill pixels using outermost pixels
+
+	   mirror
+	       fill pixels using mirroring (half sample symmetric)
+
+	   fixed
+	       fill pixels with constant value
+
+	   reflect
+	       fill pixels using reflecting (whole sample symmetric)
+
+	   wrap
+	       fill pixels using wrapping
+
+	   fade
+	       fade pixels to constant value
+
+	   margins
+	       fill pixels at top and bottom with weighted averages pixels
+	       near borders
+
+	   Default is smear.
+
+       color
+	   Set color for pixels in fixed or fade mode. Default is black.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   find_rect
+       Find a rectangular object
+
+       It accepts the following options:
+
+       object
+	   Filepath of the object image, needs to be in gray8.
+
+       threshold
+	   Detection threshold, default is 0.5.
+
+       mipmaps
+	   Number of mipmaps, default is 3.
+
+       xmin, ymin, xmax, ymax
+	   Specifies the rectangle in which to search.
+
+       discard
+	   Discard frames where object is not detected. Default is disabled.
+
+       Examples
+
+       o   Cover a rectangular object by the supplied image of a given video
+	   using ffmpeg:
+
+		   ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
+
+   floodfill
+       Flood area with values of same pixel components with another values.
+
+       It accepts the following options:
+
+       x   Set pixel x coordinate.
+
+       y   Set pixel y coordinate.
+
+       s0  Set source #0 component value.
+
+       s1  Set source #1 component value.
+
+       s2  Set source #2 component value.
+
+       s3  Set source #3 component value.
+
+       d0  Set destination #0 component value.
+
+       d1  Set destination #1 component value.
+
+       d2  Set destination #2 component value.
+
+       d3  Set destination #3 component value.
+
+   format
+       Convert the input video to one of the specified pixel formats.
+       Libavfilter will try to pick one that is suitable as input to the next
+       filter.
+
+       It accepts the following parameters:
+
+       pix_fmts
+	   A '|'-separated list of pixel format names, such as
+	   "pix_fmts=yuv420p|monow|rgb24".
+
+       Examples
+
+       o   Convert the input video to the yuv420p format
+
+		   format=pix_fmts=yuv420p
+
+	   Convert the input video to any of the formats in the list
+
+		   format=pix_fmts=yuv420p|yuv444p|yuv410p
+
+   fps
+       Convert the video to specified constant frame rate by duplicating or
+       dropping frames as necessary.
+
+       It accepts the following parameters:
+
+       fps The desired output frame rate. It accepts expressions containing
+	   the following constants:
+
+	   source_fps
+	       The input's frame rate
+
+	   ntsc
+	       NTSC frame rate of "30000/1001"
+
+	   pal PAL frame rate of 25.0
+
+	   film
+	       Film frame rate of 24.0
+
+	   ntsc_film
+	       NTSC-film frame rate of "24000/1001"
+
+	   The default is 25.
+
+       start_time
+	   Assume the first PTS should be the given value, in seconds. This
+	   allows for padding/trimming at the start of stream. By default, no
+	   assumption is made about the first frame's expected PTS, so no
+	   padding or trimming is done.  For example, this could be set to 0
+	   to pad the beginning with duplicates of the first frame if a video
+	   stream starts after the audio stream or to trim any frames with a
+	   negative PTS.
+
+       round
+	   Timestamp (PTS) rounding method.
+
+	   Possible values are:
+
+	   zero
+	       round towards 0
+
+	   inf round away from 0
+
+	   down
+	       round towards -infinity
+
+	   up  round towards +infinity
+
+	   near
+	       round to nearest
+
+	   The default is "near".
+
+       eof_action
+	   Action performed when reading the last frame.
+
+	   Possible values are:
+
+	   round
+	       Use same timestamp rounding method as used for other frames.
+
+	   pass
+	       Pass through last frame if input duration has not been reached
+	       yet.
+
+	   The default is "round".
+
+       Alternatively, the options can be specified as a flat string:
+       fps[:start_time[:round]].
+
+       See also the setpts filter.
+
+       Examples
+
+       o   A typical usage in order to set the fps to 25:
+
+		   fps=fps=25
+
+       o   Sets the fps to 24, using abbreviation and rounding method to round
+	   to nearest:
+
+		   fps=fps=film:round=near
+
+   framepack
+       Pack two different video streams into a stereoscopic video, setting
+       proper metadata on supported codecs. The two views should have the same
+       size and framerate and processing will stop when the shorter video
+       ends. Please note that you may conveniently adjust view properties with
+       the scale and fps filters.
+
+       It accepts the following parameters:
+
+       format
+	   The desired packing format. Supported values are:
+
+	   sbs The views are next to each other (default).
+
+	   tab The views are on top of each other.
+
+	   lines
+	       The views are packed by line.
+
+	   columns
+	       The views are packed by column.
+
+	   frameseq
+	       The views are temporally interleaved.
+
+       Some examples:
+
+	       # Convert left and right views into a frame-sequential video
+	       ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
+
+	       # Convert views into a side-by-side video with the same output resolution as the input
+	       ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
+
+   framerate
+       Change the frame rate by interpolating new video output frames from the
+       source frames.
+
+       This filter is not designed to function correctly with interlaced
+       media. If you wish to change the frame rate of interlaced media then
+       you are required to deinterlace before this filter and re-interlace
+       after this filter.
+
+       A description of the accepted options follows.
+
+       fps Specify the output frames per second. This option can also be
+	   specified as a value alone. The default is 50.
+
+       interp_start
+	   Specify the start of a range where the output frame will be created
+	   as a linear interpolation of two frames. The range is [0-255], the
+	   default is 15.
+
+       interp_end
+	   Specify the end of a range where the output frame will be created
+	   as a linear interpolation of two frames. The range is [0-255], the
+	   default is 240.
+
+       scene
+	   Specify the level at which a scene change is detected as a value
+	   between 0 and 100 to indicate a new scene; a low value reflects a
+	   low probability for the current frame to introduce a new scene,
+	   while a higher value means the current frame is more likely to be
+	   one.  The default is 8.2.
+
+       flags
+	   Specify flags influencing the filter process.
+
+	   Available value for flags is:
+
+	   scene_change_detect, scd
+	       Enable scene change detection using the value of the option
+	       scene.  This flag is enabled by default.
+
+   framestep
+       Select one frame every N-th frame.
+
+       This filter accepts the following option:
+
+       step
+	   Select frame after every "step" frames.  Allowed values are
+	   positive integers higher than 0. Default value is 1.
+
+   freezedetect
+       Detect frozen video.
+
+       This filter logs a message and sets frame metadata when it detects that
+       the input video has no significant change in content during a specified
+       duration.  Video freeze detection calculates the mean average absolute
+       difference of all the components of video frames and compares it to a
+       noise floor.
+
+       The printed times and duration are expressed in seconds. The
+       "lavfi.freezedetect.freeze_start" metadata key is set on the first
+       frame whose timestamp equals or exceeds the detection duration and it
+       contains the timestamp of the first frame of the freeze. The
+       "lavfi.freezedetect.freeze_duration" and
+       "lavfi.freezedetect.freeze_end" metadata keys are set on the first
+       frame after the freeze.
+
+       The filter accepts the following options:
+
+       noise, n
+	   Set noise tolerance. Can be specified in dB (in case "dB" is
+	   appended to the specified value) or as a difference ratio between 0
+	   and 1. Default is -60dB, or 0.001.
+
+       duration, d
+	   Set freeze duration until notification (default is 2 seconds).
+
+   freezeframes
+       Freeze video frames.
+
+       This filter freezes video frames using frame from 2nd input.
+
+       The filter accepts the following options:
+
+       first
+	   Set number of first frame from which to start freeze.
+
+       last
+	   Set number of last frame from which to end freeze.
+
+       replace
+	   Set number of frame from 2nd input which will be used instead of
+	   replaced frames.
+
+   frei0r
+       Apply a frei0r effect to the input video.
+
+       To enable the compilation of this filter, you need to install the
+       frei0r header and configure FFmpeg with "--enable-frei0r".
+
+       It accepts the following parameters:
+
+       filter_name
+	   The name of the frei0r effect to load. If the environment variable
+	   FREI0R_PATH is defined, the frei0r effect is searched for in each
+	   of the directories specified by the colon-separated list in
+	   FREI0R_PATH.  Otherwise, the standard frei0r paths are searched, in
+	   this order: HOME/.frei0r-1/lib/, /usr/local/lib/frei0r-1/,
+	   /usr/lib/frei0r-1/.
+
+       filter_params
+	   A '|'-separated list of parameters to pass to the frei0r effect.
+
+       A frei0r effect parameter can be a boolean (its value is either "y" or
+       "n"), a double, a color (specified as R/G/B, where R, G, and B are
+       floating point numbers between 0.0 and 1.0, inclusive) or a color
+       description as specified in the "Color" section in the ffmpeg-utils
+       manual, a position (specified as X/Y, where X and Y are floating point
+       numbers) and/or a string.
+
+       The number and types of parameters depend on the loaded effect. If an
+       effect parameter is not specified, the default value is set.
+
+       Examples
+
+       o   Apply the distort0r effect, setting the first two double
+	   parameters:
+
+		   frei0r=filter_name=distort0r:filter_params=0.5|0.01
+
+       o   Apply the colordistance effect, taking a color as the first
+	   parameter:
+
+		   frei0r=colordistance:0.2/0.3/0.4
+		   frei0r=colordistance:violet
+		   frei0r=colordistance:0x112233
+
+       o   Apply the perspective effect, specifying the top left and top right
+	   image positions:
+
+		   frei0r=perspective:0.2/0.2|0.8/0.2
+
+       For more information, see <http://frei0r.dyne.org>
+
+       Commands
+
+       This filter supports the filter_params option as commands.
+
+   fspp
+       Apply fast and simple postprocessing. It is a faster version of spp.
+
+       It splits (I)DCT into horizontal/vertical passes. Unlike the simple
+       post- processing filter, one of them is performed once per block, not
+       per pixel.  This allows for much higher speed.
+
+       The filter accepts the following options:
+
+       quality
+	   Set quality. This option defines the number of levels for
+	   averaging. It accepts an integer in the range 4-5. Default value is
+	   4.
+
+       qp  Force a constant quantization parameter. It accepts an integer in
+	   range 0-63.	If not set, the filter will use the QP from the video
+	   stream (if available).
+
+       strength
+	   Set filter strength. It accepts an integer in range -15 to 32.
+	   Lower values mean more details but also more artifacts, while
+	   higher values make the image smoother but also blurrier. Default
+	   value is 0 X PSNR optimal.
+
+       use_bframe_qp
+	   Enable the use of the QP from the B-Frames if set to 1. Using this
+	   option may cause flicker since the B-Frames have often larger QP.
+	   Default is 0 (not enabled).
+
+   gblur
+       Apply Gaussian blur filter.
+
+       The filter accepts the following options:
+
+       sigma
+	   Set horizontal sigma, standard deviation of Gaussian blur. Default
+	   is 0.5.
+
+       steps
+	   Set number of steps for Gaussian approximation. Default is 1.
+
+       planes
+	   Set which planes to filter. By default all planes are filtered.
+
+       sigmaV
+	   Set vertical sigma, if negative it will be same as "sigma".
+	   Default is "-1".
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   geq
+       Apply generic equation to each pixel.
+
+       The filter accepts the following options:
+
+       lum_expr, lum
+	   Set the luminance expression.
+
+       cb_expr, cb
+	   Set the chrominance blue expression.
+
+       cr_expr, cr
+	   Set the chrominance red expression.
+
+       alpha_expr, a
+	   Set the alpha expression.
+
+       red_expr, r
+	   Set the red expression.
+
+       green_expr, g
+	   Set the green expression.
+
+       blue_expr, b
+	   Set the blue expression.
+
+       The colorspace is selected according to the specified options. If one
+       of the lum_expr, cb_expr, or cr_expr options is specified, the filter
+       will automatically select a YCbCr colorspace. If one of the red_expr,
+       green_expr, or blue_expr options is specified, it will select an RGB
+       colorspace.
+
+       If one of the chrominance expression is not defined, it falls back on
+       the other one. If no alpha expression is specified it will evaluate to
+       opaque value.  If none of chrominance expressions are specified, they
+       will evaluate to the luminance expression.
+
+       The expressions can use the following variables and functions:
+
+       N   The sequential number of the filtered frame, starting from 0.
+
+       X
+       Y   The coordinates of the current sample.
+
+       W
+       H   The width and height of the image.
+
+       SW
+       SH  Width and height scale depending on the currently filtered plane.
+	   It is the ratio between the corresponding luma plane number of
+	   pixels and the current plane ones. E.g. for YUV4:2:0 the values are
+	   "1,1" for the luma plane, and "0.5,0.5" for chroma planes.
+
+       T   Time of the current frame, expressed in seconds.
+
+       p(x, y)
+	   Return the value of the pixel at location (x,y) of the current
+	   plane.
+
+       lum(x, y)
+	   Return the value of the pixel at location (x,y) of the luminance
+	   plane.
+
+       cb(x, y)
+	   Return the value of the pixel at location (x,y) of the blue-
+	   difference chroma plane. Return 0 if there is no such plane.
+
+       cr(x, y)
+	   Return the value of the pixel at location (x,y) of the red-
+	   difference chroma plane. Return 0 if there is no such plane.
+
+       r(x, y)
+       g(x, y)
+       b(x, y)
+	   Return the value of the pixel at location (x,y) of the
+	   red/green/blue component. Return 0 if there is no such component.
+
+       alpha(x, y)
+	   Return the value of the pixel at location (x,y) of the alpha plane.
+	   Return 0 if there is no such plane.
+
+       psum(x,y), lumsum(x, y), cbsum(x,y), crsum(x,y), rsum(x,y), gsum(x,y),
+       bsum(x,y), alphasum(x,y)
+	   Sum of sample values in the rectangle from (0,0) to (x,y), this
+	   allows obtaining sums of samples within a rectangle. See the
+	   functions without the sum postfix.
+
+       interpolation
+	   Set one of interpolation methods:
+
+	   nearest, n
+	   bilinear, b
+
+	   Default is bilinear.
+
+       For functions, if x and y are outside the area, the value will be
+       automatically clipped to the closer edge.
+
+       Please note that this filter can use multiple threads in which case
+       each slice will have its own expression state. If you want to use only
+       a single expression state because your expressions depend on previous
+       state then you should limit the number of filter threads to 1.
+
+       Examples
+
+       o   Flip the image horizontally:
+
+		   geq=p(W-X\,Y)
+
+       o   Generate a bidimensional sine wave, with angle "PI/3" and a
+	   wavelength of 100 pixels:
+
+		   geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
+
+       o   Generate a fancy enigmatic moving light:
+
+		   nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
+
+       o   Generate a quick emboss effect:
+
+		   format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
+
+       o   Modify RGB components depending on pixel position:
+
+		   geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
+
+       o   Create a radial gradient that is the same size as the input (also
+	   see the vignette filter):
+
+		   geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
+
+   gradfun
+       Fix the banding artifacts that are sometimes introduced into nearly
+       flat regions by truncation to 8-bit color depth.  Interpolate the
+       gradients that should go where the bands are, and dither them.
+
+       It is designed for playback only.  Do not use it prior to lossy
+       compression, because compression tends to lose the dither and bring
+       back the bands.
+
+       It accepts the following parameters:
+
+       strength
+	   The maximum amount by which the filter will change any one pixel.
+	   This is also the threshold for detecting nearly flat regions.
+	   Acceptable values range from .51 to 64; the default value is 1.2.
+	   Out-of-range values will be clipped to the valid range.
+
+       radius
+	   The neighborhood to fit the gradient to. A larger radius makes for
+	   smoother gradients, but also prevents the filter from modifying the
+	   pixels near detailed regions. Acceptable values are 8-32; the
+	   default value is 16. Out-of-range values will be clipped to the
+	   valid range.
+
+       Alternatively, the options can be specified as a flat string:
+       strength[:radius]
+
+       Examples
+
+       o   Apply the filter with a 3.5 strength and radius of 8:
+
+		   gradfun=3.5:8
+
+       o   Specify radius, omitting the strength (which will fall-back to the
+	   default value):
+
+		   gradfun=radius=8
+
+   graphmonitor
+       Show various filtergraph stats.
+
+       With this filter one can debug complete filtergraph.  Especially issues
+       with links filling with queued frames.
+
+       The filter accepts the following options:
+
+       size, s
+	   Set video output size. Default is hd720.
+
+       opacity, o
+	   Set video opacity. Default is 0.9. Allowed range is from 0 to 1.
+
+       mode, m
+	   Set output mode, can be fulll or compact.  In compact mode only
+	   filters with some queued frames have displayed stats.
+
+       flags, f
+	   Set flags which enable which stats are shown in video.
+
+	   Available values for flags are:
+
+	   queue
+	       Display number of queued frames in each link.
+
+	   frame_count_in
+	       Display number of frames taken from filter.
+
+	   frame_count_out
+	       Display number of frames given out from filter.
+
+	   frame_count_delta
+	       Display delta number of frames between above two values.
+
+	   pts Display current filtered frame pts.
+
+	   pts_delta
+	       Display pts delta between current and previous frame.
+
+	   time
+	       Display current filtered frame time.
+
+	   time_delta
+	       Display time delta between current and previous frame.
+
+	   timebase
+	       Display time base for filter link.
+
+	   format
+	       Display used format for filter link.
+
+	   size
+	       Display video size or number of audio channels in case of audio
+	       used by filter link.
+
+	   rate
+	       Display video frame rate or sample rate in case of audio used
+	       by filter link.
+
+	   eof Display link output status.
+
+	   sample_count_in
+	       Display number of samples taken from filter.
+
+	   sample_count_out
+	       Display number of samples given out from filter.
+
+	   sample_count_delta
+	       Display delta number of samples between above two values.
+
+       rate, r
+	   Set upper limit for video rate of output stream, Default value is
+	   25.	This guarantee that output video frame rate will not be higher
+	   than this value.
+
+   grayworld
+       A color constancy filter that applies color correction based on the
+       grayworld assumption
+
+       See:
+       <https://www.researchgate.net/publication/275213614_A_New_Color_Correction_Method_for_Underwater_Imaging>
+
+       The algorithm  uses linear light, so input data should be linearized
+       beforehand (and possibly correctly tagged).
+
+	       ffmpeg -i INPUT -vf zscale=transfer=linear,grayworld,zscale=transfer=bt709,format=yuv420p OUTPUT
+
+   greyedge
+       A color constancy variation filter which estimates scene illumination
+       via grey edge algorithm and corrects the scene colors accordingly.
+
+       See: <https://staff.science.uva.nl/th.gevers/pub/GeversTIP07.pdf>
+
+       The filter accepts the following options:
+
+       difford
+	   The order of differentiation to be applied on the scene. Must be
+	   chosen in the range [0,2] and default value is 1.
+
+       minknorm
+	   The Minkowski parameter to be used for calculating the Minkowski
+	   distance. Must be chosen in the range [0,20] and default value is
+	   1. Set to 0 for getting max value instead of calculating Minkowski
+	   distance.
+
+       sigma
+	   The standard deviation of Gaussian blur to be applied on the scene.
+	   Must be chosen in the range [0,1024.0] and default value = 1.
+	   floor( sigma * break_off_sigma(3) ) can't be equal to 0 if difford
+	   is greater than 0.
+
+       Examples
+
+       o   Grey Edge:
+
+		   greyedge=difford=1:minknorm=5:sigma=2
+
+       o   Max Edge:
+
+		   greyedge=difford=1:minknorm=0:sigma=2
+
+   guided
+       Apply guided filter for edge-preserving smoothing, dehazing and so on.
+
+       The filter accepts the following options:
+
+       radius
+	   Set the box radius in pixels.  Allowed range is 1 to 20. Default is
+	   3.
+
+       eps Set regularization parameter (with square).	Allowed range is 0 to
+	   1. Default is 0.01.
+
+       mode
+	   Set filter mode. Can be "basic" or "fast".  Default is "basic".
+
+       sub Set subsampling ratio for "fast" mode.  Range is 2 to 64. Default
+	   is 4.  No subsampling occurs in "basic" mode.
+
+       guidance
+	   Set guidance mode. Can be "off" or "on". Default is "off".  If
+	   "off", single input is required.  If "on", two inputs of the same
+	   resolution and pixel format are required.  The second input serves
+	   as the guidance.
+
+       planes
+	   Set planes to filter. Default is first only.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Edge-preserving smoothing with guided filter:
+
+		   ffmpeg -i in.png -vf guided out.png
+
+       o   Dehazing, structure-transferring filtering, detail enhancement with
+	   guided filter.  For the generation of guidance image, refer to
+	   paper "Guided Image Filtering".  See:
+	   <http://kaiminghe.com/publications/pami12guidedfilter.pdf>.
+
+		   ffmpeg -i in.png -i guidance.png -filter_complex guided=guidance=on out.png
+
+   haldclut
+       Apply a Hald CLUT to a video stream.
+
+       First input is the video stream to process, and second one is the Hald
+       CLUT.  The Hald CLUT input can be a simple picture or a complete video
+       stream.
+
+       The filter accepts the following options:
+
+       clut
+	   Set which CLUT video frames will be processed from second input
+	   stream, can be first or all. Default is all.
+
+       shortest
+	   Force termination when the shortest input terminates. Default is 0.
+
+       repeatlast
+	   Continue applying the last CLUT after the end of the stream. A
+	   value of 0 disable the filter after the last frame of the CLUT is
+	   reached.  Default is 1.
+
+       "haldclut" also has the same interpolation options as lut3d (both
+       filters share the same internals).
+
+       This filter also supports the framesync options.
+
+       More information about the Hald CLUT can be found on Eskil Steenberg's
+       website (Hald CLUT author) at
+       <http://www.quelsolaar.com/technology/clut.html>.
+
+       Commands
+
+       This filter supports the "interp" option as commands.
+
+       Workflow examples
+
+       Hald CLUT video stream
+
+       Generate an identity Hald CLUT stream altered with various effects:
+
+	       ffmpeg -f lavfi -i B<haldclutsrc>=8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
+
+       Note: make sure you use a lossless codec.
+
+       Then use it with "haldclut" to apply it on some random stream:
+
+	       ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
+
+       The Hald CLUT will be applied to the 10 first seconds (duration of
+       clut.nut), then the latest picture of that CLUT stream will be applied
+       to the remaining frames of the "mandelbrot" stream.
+
+       Hald CLUT with preview
+
+       A Hald CLUT is supposed to be a squared image of "Level*Level*Level" by
+       "Level*Level*Level" pixels. For a given Hald CLUT, FFmpeg will select
+       the biggest possible square starting at the top left of the picture.
+       The remaining padding pixels (bottom or right) will be ignored. This
+       area can be used to add a preview of the Hald CLUT.
+
+       Typically, the following generated Hald CLUT will be supported by the
+       "haldclut" filter:
+
+	       ffmpeg -f lavfi -i B<haldclutsrc>=8 -vf "
+		  pad=iw+320 [padded_clut];
+		  smptebars=s=320x256, split [a][b];
+		  [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
+		  [main][b] overlay=W-320" -frames:v 1 clut.png
+
+       It contains the original and a preview of the effect of the CLUT: SMPTE
+       color bars are displayed on the right-top, and below the same color
+       bars processed by the color changes.
+
+       Then, the effect of this Hald CLUT can be visualized with:
+
+	       ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
+
+   hflip
+       Flip the input video horizontally.
+
+       For example, to horizontally flip the input video with ffmpeg:
+
+	       ffmpeg -i in.avi -vf "hflip" out.avi
+
+   histeq
+       This filter applies a global color histogram equalization on a per-
+       frame basis.
+
+       It can be used to correct video that has a compressed range of pixel
+       intensities.  The filter redistributes the pixel intensities to
+       equalize their distribution across the intensity range. It may be
+       viewed as an "automatically adjusting contrast filter". This filter is
+       useful only for correcting degraded or poorly captured source video.
+
+       The filter accepts the following options:
+
+       strength
+	   Determine the amount of equalization to be applied.	As the
+	   strength is reduced, the distribution of pixel intensities more-
+	   and-more approaches that of the input frame. The value must be a
+	   float number in the range [0,1] and defaults to 0.200.
+
+       intensity
+	   Set the maximum intensity that can generated and scale the output
+	   values appropriately.  The strength should be set as desired and
+	   then the intensity can be limited if needed to avoid washing-out.
+	   The value must be a float number in the range [0,1] and defaults to
+	   0.210.
+
+       antibanding
+	   Set the antibanding level. If enabled the filter will randomly vary
+	   the luminance of output pixels by a small amount to avoid banding
+	   of the histogram. Possible values are "none", "weak" or "strong".
+	   It defaults to "none".
+
+   histogram
+       Compute and draw a color distribution histogram for the input video.
+
+       The computed histogram is a representation of the color component
+       distribution in an image.
+
+       Standard histogram displays the color components distribution in an
+       image.  Displays color graph for each color component. Shows
+       distribution of the Y, U, V, A or R, G, B components, depending on
+       input format, in the current frame. Below each graph a color component
+       scale meter is shown.
+
+       The filter accepts the following options:
+
+       level_height
+	   Set height of level. Default value is 200.  Allowed range is [50,
+	   2048].
+
+       scale_height
+	   Set height of color scale. Default value is 12.  Allowed range is
+	   [0, 40].
+
+       display_mode
+	   Set display mode.  It accepts the following values:
+
+	   stack
+	       Per color component graphs are placed below each other.
+
+	   parade
+	       Per color component graphs are placed side by side.
+
+	   overlay
+	       Presents information identical to that in the "parade", except
+	       that the graphs representing color components are superimposed
+	       directly over one another.
+
+	   Default is "stack".
+
+       levels_mode
+	   Set mode. Can be either "linear", or "logarithmic".	Default is
+	   "linear".
+
+       components
+	   Set what color components to display.  Default is 7.
+
+       fgopacity
+	   Set foreground opacity. Default is 0.7.
+
+       bgopacity
+	   Set background opacity. Default is 0.5.
+
+       colors_mode
+	   Set colors mode.  It accepts the following values:
+
+	   whiteonblack
+	   blackonwhite
+	   whiteongray
+	   blackongray
+	   coloronblack
+	   coloronwhite
+	   colorongray
+	   blackoncolor
+	   whiteoncolor
+	   grayoncolor
+
+	   Default is "whiteonblack".
+
+       Examples
+
+       o   Calculate and draw histogram:
+
+		   ffplay -i input -vf histogram
+
+   hqdn3d
+       This is a high precision/quality 3d denoise filter. It aims to reduce
+       image noise, producing smooth images and making still images really
+       still. It should enhance compressibility.
+
+       It accepts the following optional parameters:
+
+       luma_spatial
+	   A non-negative floating point number which specifies spatial luma
+	   strength.  It defaults to 4.0.
+
+       chroma_spatial
+	   A non-negative floating point number which specifies spatial chroma
+	   strength.  It defaults to 3.0*luma_spatial/4.0.
+
+       luma_tmp
+	   A floating point number which specifies luma temporal strength. It
+	   defaults to 6.0*luma_spatial/4.0.
+
+       chroma_tmp
+	   A floating point number which specifies chroma temporal strength.
+	   It defaults to luma_tmp*chroma_spatial/luma_spatial.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   hwdownload
+       Download hardware frames to system memory.
+
+       The input must be in hardware frames, and the output a non-hardware
+       format.	Not all formats will be supported on the output - it may be
+       necessary to insert an additional format filter immediately following
+       in the graph to get the output in a supported format.
+
+   hwmap
+       Map hardware frames to system memory or to another device.
+
+       This filter has several different modes of operation; which one is used
+       depends on the input and output formats:
+
+       o   Hardware frame input, normal frame output
+
+	   Map the input frames to system memory and pass them to the output.
+	   If the original hardware frame is later required (for example,
+	   after overlaying something else on part of it), the hwmap filter
+	   can be used again in the next mode to retrieve it.
+
+       o   Normal frame input, hardware frame output
+
+	   If the input is actually a software-mapped hardware frame, then
+	   unmap it - that is, return the original hardware frame.
+
+	   Otherwise, a device must be provided.  Create new hardware surfaces
+	   on that device for the output, then map them back to the software
+	   format at the input and give those frames to the preceding filter.
+	   This will then act like the hwupload filter, but may be able to
+	   avoid an additional copy when the input is already in a compatible
+	   format.
+
+       o   Hardware frame input and output
+
+	   A device must be supplied for the output, either directly or with
+	   the derive_device option.  The input and output devices must be of
+	   different types and compatible - the exact meaning of this is
+	   system-dependent, but typically it means that they must refer to
+	   the same underlying hardware context (for example, refer to the
+	   same graphics card).
+
+	   If the input frames were originally created on the output device,
+	   then unmap to retrieve the original frames.
+
+	   Otherwise, map the frames to the output device - create new
+	   hardware frames on the output corresponding to the frames on the
+	   input.
+
+       The following additional parameters are accepted:
+
+       mode
+	   Set the frame mapping mode.	Some combination of:
+
+	   read
+	       The mapped frame should be readable.
+
+	   write
+	       The mapped frame should be writeable.
+
+	   overwrite
+	       The mapping will always overwrite the entire frame.
+
+	       This may improve performance in some cases, as the original
+	       contents of the frame need not be loaded.
+
+	   direct
+	       The mapping must not involve any copying.
+
+	       Indirect mappings to copies of frames are created in some cases
+	       where either direct mapping is not possible or it would have
+	       unexpected properties.  Setting this flag ensures that the
+	       mapping is direct and will fail if that is not possible.
+
+	   Defaults to read+write if not specified.
+
+       derive_device type
+	   Rather than using the device supplied at initialisation, instead
+	   derive a new device of type type from the device the input frames
+	   exist on.
+
+       reverse
+	   In a hardware to hardware mapping, map in reverse - create frames
+	   in the sink and map them back to the source.  This may be necessary
+	   in some cases where a mapping in one direction is required but only
+	   the opposite direction is supported by the devices being used.
+
+	   This option is dangerous - it may break the preceding filter in
+	   undefined ways if there are any additional constraints on that
+	   filter's output.  Do not use it without fully understanding the
+	   implications of its use.
+
+   hwupload
+       Upload system memory frames to hardware surfaces.
+
+       The device to upload to must be supplied when the filter is
+       initialised.  If using ffmpeg, select the appropriate device with the
+       -filter_hw_device option or with the derive_device option.  The input
+       and output devices must be of different types and compatible - the
+       exact meaning of this is system-dependent, but typically it means that
+       they must refer to the same underlying hardware context (for example,
+       refer to the same graphics card).
+
+       The following additional parameters are accepted:
+
+       derive_device type
+	   Rather than using the device supplied at initialisation, instead
+	   derive a new device of type type from the device the input frames
+	   exist on.
+
+   hwupload_cuda
+       Upload system memory frames to a CUDA device.
+
+       It accepts the following optional parameters:
+
+       device
+	   The number of the CUDA device to use
+
+   hqx
+       Apply a high-quality magnification filter designed for pixel art. This
+       filter was originally created by Maxim Stepin.
+
+       It accepts the following option:
+
+       n   Set the scaling dimension: 2 for "hq2x", 3 for "hq3x" and 4 for
+	   "hq4x".  Default is 3.
+
+   hstack
+       Stack input videos horizontally.
+
+       All streams must be of same pixel format and of same height.
+
+       Note that this filter is faster than using overlay and pad filter to
+       create same output.
+
+       The filter accepts the following option:
+
+       inputs
+	   Set number of input streams. Default is 2.
+
+       shortest
+	   If set to 1, force the output to terminate when the shortest input
+	   terminates. Default value is 0.
+
+   hsvhold
+       Turns a certain HSV range into gray values.
+
+       This filter measures color difference between set HSV color in options
+       and ones measured in video stream. Depending on options, output colors
+       can be changed to be gray or not.
+
+       The filter accepts the following options:
+
+       hue Set the hue value which will be used in color difference
+	   calculation.  Allowed range is from -360 to 360. Default value is
+	   0.
+
+       sat Set the saturation value which will be used in color difference
+	   calculation.  Allowed range is from -1 to 1. Default value is 0.
+
+       val Set the value which will be used in color difference calculation.
+	   Allowed range is from -1 to 1. Default value is 0.
+
+       similarity
+	   Set similarity percentage with the key color.  Allowed range is
+	   from 0 to 1. Default value is 0.01.
+
+	   0.00001 matches only the exact key color, while 1.0 matches
+	   everything.
+
+       blend
+	   Blend percentage.  Allowed range is from 0 to 1. Default value is
+	   0.
+
+	   0.0 makes pixels either fully gray, or not gray at all.
+
+	   Higher values result in more gray pixels, with a higher gray pixel
+	   the more similar the pixels color is to the key color.
+
+   hsvkey
+       Turns a certain HSV range into transparency.
+
+       This filter measures color difference between set HSV color in options
+       and ones measured in video stream. Depending on options, output colors
+       can be changed to transparent by adding alpha channel.
+
+       The filter accepts the following options:
+
+       hue Set the hue value which will be used in color difference
+	   calculation.  Allowed range is from -360 to 360. Default value is
+	   0.
+
+       sat Set the saturation value which will be used in color difference
+	   calculation.  Allowed range is from -1 to 1. Default value is 0.
+
+       val Set the value which will be used in color difference calculation.
+	   Allowed range is from -1 to 1. Default value is 0.
+
+       similarity
+	   Set similarity percentage with the key color.  Allowed range is
+	   from 0 to 1. Default value is 0.01.
+
+	   0.00001 matches only the exact key color, while 1.0 matches
+	   everything.
+
+       blend
+	   Blend percentage.  Allowed range is from 0 to 1. Default value is
+	   0.
+
+	   0.0 makes pixels either fully transparent, or not transparent at
+	   all.
+
+	   Higher values result in semi-transparent pixels, with a higher
+	   transparency the more similar the pixels color is to the key color.
+
+   hue
+       Modify the hue and/or the saturation of the input.
+
+       It accepts the following parameters:
+
+       h   Specify the hue angle as a number of degrees. It accepts an
+	   expression, and defaults to "0".
+
+       s   Specify the saturation in the [-10,10] range. It accepts an
+	   expression and defaults to "1".
+
+       H   Specify the hue angle as a number of radians. It accepts an
+	   expression, and defaults to "0".
+
+       b   Specify the brightness in the [-10,10] range. It accepts an
+	   expression and defaults to "0".
+
+       h and H are mutually exclusive, and can't be specified at the same
+       time.
+
+       The b, h, H and s option values are expressions containing the
+       following constants:
+
+       n   frame count of the input frame starting from 0
+
+       pts presentation timestamp of the input frame expressed in time base
+	   units
+
+       r   frame rate of the input video, NAN if the input frame rate is
+	   unknown
+
+       t   timestamp expressed in seconds, NAN if the input timestamp is
+	   unknown
+
+       tb  time base of the input video
+
+       Examples
+
+       o   Set the hue to 90 degrees and the saturation to 1.0:
+
+		   hue=h=90:s=1
+
+       o   Same command but expressing the hue in radians:
+
+		   hue=H=PI/2:s=1
+
+       o   Rotate hue and make the saturation swing between 0 and 2 over a
+	   period of 1 second:
+
+		   hue="H=2*PI*t: s=sin(2*PI*t)+1"
+
+       o   Apply a 3 seconds saturation fade-in effect starting at 0:
+
+		   hue="s=min(t/3\,1)"
+
+	   The general fade-in expression can be written as:
+
+		   hue="s=min(0\, max((t-START)/DURATION\, 1))"
+
+       o   Apply a 3 seconds saturation fade-out effect starting at 5 seconds:
+
+		   hue="s=max(0\, min(1\, (8-t)/3))"
+
+	   The general fade-out expression can be written as:
+
+		   hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
+
+       Commands
+
+       This filter supports the following commands:
+
+       b
+       s
+       h
+       H   Modify the hue and/or the saturation and/or brightness of the input
+	   video.  The command accepts the same syntax of the corresponding
+	   option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   huesaturation
+       Apply hue-saturation-intensity adjustments to input video stream.
+
+       This filter operates in RGB colorspace.
+
+       This filter accepts the following options:
+
+       hue Set the hue shift in degrees to apply. Default is 0.  Allowed range
+	   is from -180 to 180.
+
+       saturation
+	   Set the saturation shift. Default is 0.  Allowed range is from -1
+	   to 1.
+
+       intensity
+	   Set the intensity shift. Default is 0.  Allowed range is from -1 to
+	   1.
+
+       colors
+	   Set which primary and complementary colors are going to be
+	   adjusted.  This options is set by providing one or multiple values.
+	   This can select multiple colors at once. By default all colors are
+	   selected.
+
+	   r   Adjust reds.
+
+	   y   Adjust yellows.
+
+	   g   Adjust greens.
+
+	   c   Adjust cyans.
+
+	   b   Adjust blues.
+
+	   m   Adjust magentas.
+
+	   a   Adjust all colors.
+
+       strength
+	   Set strength of filtering. Allowed range is from 0 to 100.  Default
+	   value is 1.
+
+       rw, gw, bw
+	   Set weight for each RGB component. Allowed range is from 0 to 1.
+	   By default is set to 0.333, 0.334, 0.333.  Those options are used
+	   in saturation and lightess processing.
+
+       lightness
+	   Set preserving lightness, by default is disabled.  Adjusting hues
+	   can change lightness from original RGB triplet, with this option
+	   enabled lightness is kept at same value.
+
+   hysteresis
+       Grow first stream into second stream by connecting components.  This
+       makes it possible to build more robust edge masks.
+
+       This filter accepts the following options:
+
+       planes
+	   Set which planes will be processed as bitmap, unprocessed planes
+	   will be copied from first stream.  By default value 0xf, all planes
+	   will be processed.
+
+       threshold
+	   Set threshold which is used in filtering. If pixel component value
+	   is higher than this value filter algorithm for connecting
+	   components is activated.  By default value is 0.
+
+       The "hysteresis" filter also supports the framesync options.
+
+   iccdetect
+       Detect the colorspace  from an embedded ICC profile (if present), and
+       update the frame's tags accordingly.
+
+       This filter accepts the following options:
+
+       force
+	   If true, the frame's existing colorspace tags will always be
+	   overridden by values detected from an ICC profile. Otherwise, they
+	   will only be assigned if they contain "unknown". Enabled by
+	   default.
+
+   iccgen
+       Generate ICC profiles and attach them to frames.
+
+       This filter accepts the following options:
+
+       color_primaries
+       color_trc
+	   Configure the colorspace that the ICC profile will be generated
+	   for. The default value of "auto" infers the value from the input
+	   frame's metadata, defaulting to BT.709/sRGB as appropriate.
+
+	   See the setparams filter for a list of possible values, but note
+	   that "unknown" are not valid values for this filter.
+
+       force
+	   If true, an ICC profile will be generated even if it would
+	   overwrite an already existing ICC profile. Disabled by default.
+
+   identity
+       Obtain the identity score between two input videos.
+
+       This filter takes two input videos.
+
+       Both input videos must have the same resolution and pixel format for
+       this filter to work correctly. Also it assumes that both inputs have
+       the same number of frames, which are compared one by one.
+
+       The obtained per component, average, min and max identity score is
+       printed through the logging system.
+
+       The filter stores the calculated identity scores of each frame in frame
+       metadata.
+
+       This filter also supports the framesync options.
+
+       In the below example the input file main.mpg being processed is
+       compared with the reference file ref.mpg.
+
+	       ffmpeg -i main.mpg -i ref.mpg -lavfi identity -f null -
+
+   idet
+       Detect video interlacing type.
+
+       This filter tries to detect if the input frames are interlaced,
+       progressive, top or bottom field first. It will also try to detect
+       fields that are repeated between adjacent frames (a sign of telecine).
+
+       Single frame detection considers only immediately adjacent frames when
+       classifying each frame.	Multiple frame detection incorporates the
+       classification history of previous frames.
+
+       The filter will log these metadata values:
+
+       single.current_frame
+	   Detected type of current frame using single-frame detection. One
+	   of: ``tff'' (top field first), ``bff'' (bottom field first),
+	   ``progressive'', or ``undetermined''
+
+       single.tff
+	   Cumulative number of frames detected as top field first using
+	   single-frame detection.
+
+       multiple.tff
+	   Cumulative number of frames detected as top field first using
+	   multiple-frame detection.
+
+       single.bff
+	   Cumulative number of frames detected as bottom field first using
+	   single-frame detection.
+
+       multiple.current_frame
+	   Detected type of current frame using multiple-frame detection. One
+	   of: ``tff'' (top field first), ``bff'' (bottom field first),
+	   ``progressive'', or ``undetermined''
+
+       multiple.bff
+	   Cumulative number of frames detected as bottom field first using
+	   multiple-frame detection.
+
+       single.progressive
+	   Cumulative number of frames detected as progressive using single-
+	   frame detection.
+
+       multiple.progressive
+	   Cumulative number of frames detected as progressive using multiple-
+	   frame detection.
+
+       single.undetermined
+	   Cumulative number of frames that could not be classified using
+	   single-frame detection.
+
+       multiple.undetermined
+	   Cumulative number of frames that could not be classified using
+	   multiple-frame detection.
+
+       repeated.current_frame
+	   Which field in the current frame is repeated from the last. One of
+	   ``neither'', ``top'', or ``bottom''.
+
+       repeated.neither
+	   Cumulative number of frames with no repeated field.
+
+       repeated.top
+	   Cumulative number of frames with the top field repeated from the
+	   previous frame's top field.
+
+       repeated.bottom
+	   Cumulative number of frames with the bottom field repeated from the
+	   previous frame's bottom field.
+
+       The filter accepts the following options:
+
+       intl_thres
+	   Set interlacing threshold.
+
+       prog_thres
+	   Set progressive threshold.
+
+       rep_thres
+	   Threshold for repeated field detection.
+
+       half_life
+	   Number of frames after which a given frame's contribution to the
+	   statistics is halved (i.e., it contributes only 0.5 to its
+	   classification). The default of 0 means that all frames seen are
+	   given full weight of 1.0 forever.
+
+       analyze_interlaced_flag
+	   When this is not 0 then idet will use the specified number of
+	   frames to determine if the interlaced flag is accurate, it will not
+	   count undetermined frames.  If the flag is found to be accurate it
+	   will be used without any further computations, if it is found to be
+	   inaccurate it will be cleared without any further computations.
+	   This allows inserting the idet filter as a low computational method
+	   to clean up the interlaced flag
+
+   il
+       Deinterleave or interleave fields.
+
+       This filter allows one to process interlaced images fields without
+       deinterlacing them. Deinterleaving splits the input frame into 2 fields
+       (so called half pictures). Odd lines are moved to the top half of the
+       output image, even lines to the bottom half.  You can process (filter)
+       them independently and then re-interleave them.
+
+       The filter accepts the following options:
+
+       luma_mode, l
+       chroma_mode, c
+       alpha_mode, a
+	   Available values for luma_mode, chroma_mode and alpha_mode are:
+
+	   none
+	       Do nothing.
+
+	   deinterleave, d
+	       Deinterleave fields, placing one above the other.
+
+	   interleave, i
+	       Interleave fields. Reverse the effect of deinterleaving.
+
+	   Default value is "none".
+
+       luma_swap, ls
+       chroma_swap, cs
+       alpha_swap, as
+	   Swap luma/chroma/alpha fields. Exchange even & odd lines. Default
+	   value is 0.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   inflate
+       Apply inflate effect to the video.
+
+       This filter replaces the pixel by the local(3x3) average by taking into
+       account only values higher than the pixel.
+
+       It accepts the following options:
+
+       threshold0
+       threshold1
+       threshold2
+       threshold3
+	   Limit the maximum change for each plane, default is 65535.  If 0,
+	   plane will remain unchanged.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   interlace
+       Simple interlacing filter from progressive contents. This interleaves
+       upper (or lower) lines from odd frames with lower (or upper) lines from
+       even frames, halving the frame rate and preserving image height.
+
+		  Original	  Original	       New Frame
+		  Frame 'j'	 Frame 'j+1'		 (tff)
+		 ==========	 ===========	   ==================
+		   Line 0  -------------------->    Frame 'j' Line 0
+		   Line 1	   Line 1  ---->   Frame 'j+1' Line 1
+		   Line 2 --------------------->    Frame 'j' Line 2
+		   Line 3	   Line 3  ---->   Frame 'j+1' Line 3
+		    ... 	    ... 		  ...
+	       New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
+
+       It accepts the following optional parameters:
+
+       scan
+	   This determines whether the interlaced frame is taken from the even
+	   (tff - default) or odd (bff) lines of the progressive frame.
+
+       lowpass
+	   Vertical lowpass filter to avoid twitter interlacing and reduce
+	   moire patterns.
+
+	   0, off
+	       Disable vertical lowpass filter
+
+	   1, linear
+	       Enable linear filter (default)
+
+	   2, complex
+	       Enable complex filter. This will slightly less reduce twitter
+	       and moire but better retain detail and subjective sharpness
+	       impression.
+
+   kerndeint
+       Deinterlace input video by applying Donald Graft's adaptive kernel
+       deinterling. Work on interlaced parts of a video to produce progressive
+       frames.
+
+       The description of the accepted parameters follows.
+
+       thresh
+	   Set the threshold which affects the filter's tolerance when
+	   determining if a pixel line must be processed. It must be an
+	   integer in the range [0,255] and defaults to 10. A value of 0 will
+	   result in applying the process on every pixels.
+
+       map Paint pixels exceeding the threshold value to white if set to 1.
+	   Default is 0.
+
+       order
+	   Set the fields order. Swap fields if set to 1, leave fields alone
+	   if 0. Default is 0.
+
+       sharp
+	   Enable additional sharpening if set to 1. Default is 0.
+
+       twoway
+	   Enable twoway sharpening if set to 1. Default is 0.
+
+       Examples
+
+       o   Apply default values:
+
+		   kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
+
+       o   Enable additional sharpening:
+
+		   kerndeint=sharp=1
+
+       o   Paint processed pixels in white:
+
+		   kerndeint=map=1
+
+   kirsch
+       Apply kirsch operator to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.
+
+       delta
+	   Set value which will be added to filtered result.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   lagfun
+       Slowly update darker pixels.
+
+       This filter makes short flashes of light appear longer.	This filter
+       accepts the following options:
+
+       decay
+	   Set factor for decaying. Default is .95. Allowed range is from 0 to
+	   1.
+
+       planes
+	   Set which planes to filter. Default is all. Allowed range is from 0
+	   to 15.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   lenscorrection
+       Correct radial lens distortion
+
+       This filter can be used to correct for radial distortion as can result
+       from the use of wide angle lenses, and thereby re-rectify the image. To
+       find the right parameters one can use tools available for example as
+       part of opencv or simply trial-and-error.  To use opencv use the
+       calibration sample (under samples/cpp) from the opencv sources and
+       extract the k1 and k2 coefficients from the resulting matrix.
+
+       Note that effectively the same filter is available in the open-source
+       tools Krita and Digikam from the KDE project.
+
+       In contrast to the vignette filter, which can also be used to
+       compensate lens errors, this filter corrects the distortion of the
+       image, whereas vignette corrects the brightness distribution, so you
+       may want to use both filters together in certain cases, though you will
+       have to take care of ordering, i.e. whether vignetting should be
+       applied before or after lens correction.
+
+       Options
+
+       The filter accepts the following options:
+
+       cx  Relative x-coordinate of the focal point of the image, and thereby
+	   the center of the distortion. This value has a range [0,1] and is
+	   expressed as fractions of the image width. Default is 0.5.
+
+       cy  Relative y-coordinate of the focal point of the image, and thereby
+	   the center of the distortion. This value has a range [0,1] and is
+	   expressed as fractions of the image height. Default is 0.5.
+
+       k1  Coefficient of the quadratic correction term. This value has a
+	   range [-1,1]. 0 means no correction. Default is 0.
+
+       k2  Coefficient of the double quadratic correction term. This value has
+	   a range [-1,1].  0 means no correction. Default is 0.
+
+       i   Set interpolation type. Can be "nearest" or "bilinear".  Default is
+	   "nearest".
+
+       fc  Specify the color of the unmapped pixels. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+	   Default color is "black@0".
+
+       The formula that generates the correction is:
+
+       r_src = r_tgt * (1 + k1 * (r_tgt / r_0)^2 + k2 * (r_tgt / r_0)^4)
+
+       where r_0 is halve of the image diagonal and r_src and r_tgt are the
+       distances from the focal point in the source and target images,
+       respectively.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   lensfun
+       Apply lens correction via the lensfun library
+       (<http://lensfun.sourceforge.net/>).
+
+       The "lensfun" filter requires the camera make, camera model, and lens
+       model to apply the lens correction. The filter will load the lensfun
+       database and query it to find the corresponding camera and lens entries
+       in the database. As long as these entries can be found with the given
+       options, the filter can perform corrections on frames. Note that
+       incomplete strings will result in the filter choosing the best match
+       with the given options, and the filter will output the chosen camera
+       and lens models (logged with level "info"). You must provide the make,
+       camera model, and lens model as they are required.
+
+       To obtain a list of available makes and models, leave out one or both
+       of "make" and "model" options. The filter will send the full list to
+       the log with level "INFO".  The first column is the make and the second
+       column is the model.  To obtain a list of available lenses, set any
+       values for make and model and leave out the "lens_model" option. The
+       filter will send the full list of lenses in the log with level "INFO".
+       The ffmpeg tool will exit after the list is printed.
+
+       The filter accepts the following options:
+
+       make
+	   The make of the camera (for example, "Canon"). This option is
+	   required.
+
+       model
+	   The model of the camera (for example, "Canon EOS 100D"). This
+	   option is required.
+
+       lens_model
+	   The model of the lens (for example, "Canon EF-S 18-55mm f/3.5-5.6
+	   IS STM"). This option is required.
+
+       db_path
+	   The full path to the lens database folder. If not set, the filter
+	   will attempt to load the database from the install path when the
+	   library was built. Default is unset.
+
+       mode
+	   The type of correction to apply. The following values are valid
+	   options:
+
+	   vignetting
+	       Enables fixing lens vignetting.
+
+	   geometry
+	       Enables fixing lens geometry. This is the default.
+
+	   subpixel
+	       Enables fixing chromatic aberrations.
+
+	   vig_geo
+	       Enables fixing lens vignetting and lens geometry.
+
+	   vig_subpixel
+	       Enables fixing lens vignetting and chromatic aberrations.
+
+	   distortion
+	       Enables fixing both lens geometry and chromatic aberrations.
+
+	   all Enables all possible corrections.
+
+       focal_length
+	   The focal length of the image/video (zoom; expected constant for
+	   video). For example, a 18--55mm lens has focal length range of
+	   [18--55], so a value in that range should be chosen when using that
+	   lens. Default 18.
+
+       aperture
+	   The aperture of the image/video (expected constant for video). Note
+	   that aperture is only used for vignetting correction. Default 3.5.
+
+       focus_distance
+	   The focus distance of the image/video (expected constant for
+	   video). Note that focus distance is only used for vignetting and
+	   only slightly affects the vignetting correction process. If
+	   unknown, leave it at the default value (which is 1000).
+
+       scale
+	   The scale factor which is applied after transformation. After
+	   correction the video is no longer necessarily rectangular. This
+	   parameter controls how much of the resulting image is visible. The
+	   value 0 means that a value will be chosen automatically such that
+	   there is little or no unmapped area in the output image. 1.0 means
+	   that no additional scaling is done. Lower values may result in more
+	   of the corrected image being visible, while higher values may avoid
+	   unmapped areas in the output.
+
+       target_geometry
+	   The target geometry of the output image/video. The following values
+	   are valid options:
+
+	   rectilinear (default)
+	   fisheye
+	   panoramic
+	   equirectangular
+	   fisheye_orthographic
+	   fisheye_stereographic
+	   fisheye_equisolid
+	   fisheye_thoby
+       reverse
+	   Apply the reverse of image correction (instead of correcting
+	   distortion, apply it).
+
+       interpolation
+	   The type of interpolation used when correcting distortion. The
+	   following values are valid options:
+
+	   nearest
+	   linear (default)
+	   lanczos
+
+       Examples
+
+       o   Apply lens correction with make "Canon", camera model "Canon EOS
+	   100D", and lens model "Canon EF-S 18-55mm f/3.5-5.6 IS STM" with
+	   focal length of "18" and aperture of "8.0".
+
+		   ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Canon EF-S 18-55mm f/3.5-5.6 IS STM":focal_length=18:aperture=8 -c:v h264 -b:v 8000k output.mov
+
+       o   Apply the same as before, but only for the first 5 seconds of
+	   video.
+
+		   ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Canon EF-S 18-55mm f/3.5-5.6 IS STM":focal_length=18:aperture=8:enable='lte(t\,5)' -c:v h264 -b:v 8000k output.mov
+
+   libplacebo
+       Flexible GPU-accelerated processing filter based on libplacebo
+       (<https://code.videolan.org/videolan/libplacebo>). Note that this
+       filter currently only accepts Vulkan input frames.
+
+       Options
+
+       The options for this filter are divided into the following sections:
+
+       Output mode
+
+       These options control the overall output mode. By default, libplacebo
+       will try to preserve the source colorimetry and size as best as it can,
+       but it will apply any embedded film grain, dolby vision metadata or
+       anamorphic SAR present in source frames.
+
+       w
+       h   Set the output video dimension expression. Default value is the
+	   input dimension.
+
+	   Allows for the same expressions as the scale filter.
+
+       format
+	   Set the output format override. If unset (the default), frames will
+	   be output in the same format as the respective input frames.
+	   Otherwise, format conversion will be performed.
+
+       force_original_aspect_ratio
+       force_divisible_by
+	   Work the same as the identical scale filter options.
+
+       normalize_sar
+	   If enabled, output frames will always have a pixel aspect ratio of
+	   1:1. This will introduce padding/cropping as necessary. If disabled
+	   (the default), any aspect ratio mismatches, including those from
+	   e.g. anamorphic video sources, are forwarded to the output pixel
+	   aspect ratio.
+
+       pad_crop_ratio
+	   Specifies a ratio (between 0.0 and 1.0) between padding and
+	   cropping when the input aspect ratio does not match the output
+	   aspect ratio and normalize_sar is in effect. The default of 0.0
+	   always pads the content with black borders, while a value of 1.0
+	   always crops off parts of the content. Intermediate values are
+	   possible, leading to a mix of the two approaches.
+
+       colorspace
+       color_primaries
+       color_trc
+       range
+	   Configure the colorspace that output frames will be delivered in.
+	   The default value of "auto" outputs frames in the same format as
+	   the input frames, leading to no change. For any other value,
+	   conversion will be performed.
+
+	   See the setparams filter for a list of possible values.
+
+       apply_filmgrain
+	   Apply film grain (e.g. AV1 or H.274) if present in source frames,
+	   and strip it from the output. Enabled by default.
+
+       apply_dolbyvision
+	   Apply Dolby Vision RPU metadata if present in source frames, and
+	   strip it from the output. Enabled by default. Note that Dolby
+	   Vision will always output BT.2020+PQ, overriding the usual input
+	   frame metadata. These will also be picked as the values of "auto"
+	   for the respective frame output options.
+
+       Scaling
+
+       The options in this section control how libplacebo performs upscaling
+       and (if necessary) downscaling. Note that libplacebo will always
+       internally operate on 4:4:4 content, so any sub-sampled chroma formats
+       such as "yuv420p" will necessarily be upsampled and downsampled as part
+       of the rendering process. That means scaling might be in effect even if
+       the source and destination resolution are the same.
+
+       upscaler
+       downscaler
+	   Configure the filter kernel used for upscaling and downscaling. The
+	   respective defaults are "spline36" and "mitchell". For a full list
+	   of possible values, pass "help" to these options. The most
+	   important values are:
+
+	   none
+	       Forces the use of built-in GPU texture sampling (typically
+	       bilinear). Extremely fast but poor quality, especially when
+	       downscaling.
+
+	   bilinear
+	       Bilinear interpolation. Can generally be done for free on GPUs,
+	       except when doing so would lead to aliasing. Fast and low
+	       quality.
+
+	   nearest
+	       Nearest-neighbour interpolation. Sharp but highly aliasing.
+
+	   oversample
+	       Algorithm that looks visually similar to nearest-neighbour
+	       interpolation but tries to preserve pixel aspect ratio. Good
+	       for pixel art, since it results in minimal distortion of the
+	       artistic appearance.
+
+	   lanczos
+	       Standard sinc-sinc interpolation kernel.
+
+	   spline36
+	       Cubic spline approximation of lanczos. No difference in
+	       performance, but has very slightly less ringing.
+
+	   ewa_lanczos
+	       Elliptically weighted average version of lanczos, based on a
+	       jinc-sinc kernel.  This is also popularly referred to as just
+	       "Jinc scaling". Slow but very high quality.
+
+	   gaussian
+	       Gaussian kernel. Has certain ideal mathematical properties, but
+	       subjectively very blurry.
+
+	   mitchell
+	       Cubic BC spline with parameters recommended by Mitchell and
+	       Netravali. Very little ringing.
+
+       lut_entries
+	   Configures the size of scaler LUTs, ranging from 1 to 256. The
+	   default of 0 will pick libplacebo's internal default, typically 64.
+
+       antiringing
+	   Enables anti-ringing (for non-EWA filters). The value (between 0.0
+	   and 1.0) configures the strength of the anti-ringing algorithm. May
+	   increase aliasing if set too high. Disabled by default.
+
+       sigmoid
+	   Enable sigmoidal compression during upscaling. Reduces ringing
+	   slightly.  Enabled by default.
+
+       Debanding
+
+       Libplacebo comes with a built-in debanding filter that is good at
+       counteracting many common sources of banding and blocking. Turning this
+       on is highly recommended whenever quality is desired.
+
+       deband
+	   Enable (fast) debanding algorithm. Disabled by default.
+
+       deband_iterations
+	   Number of deband iterations of the debanding algorithm. Each
+	   iteration is performed with progressively increased radius (and
+	   diminished threshold).  Recommended values are in the range 1 to 4.
+	   Defaults to 1.
+
+       deband_threshold
+	   Debanding filter strength. Higher numbers lead to more aggressive
+	   debanding.  Defaults to 4.0.
+
+       deband_radius
+	   Debanding filter radius. A higher radius is better for slow
+	   gradients, while a lower radius is better for steep gradients.
+	   Defaults to 16.0.
+
+       deband_grain
+	   Amount of extra output grain to add. Helps hide imperfections.
+	   Defaults to 6.0.
+
+       Color adjustment
+
+       A collection of subjective color controls. Not very rigorous, so the
+       exact effect will vary somewhat depending on the input primaries and
+       colorspace.
+
+       brightness
+	   Brightness boost, between "-1.0" and 1.0. Defaults to 0.0.
+
+       contrast
+	   Contrast gain, between 0.0 and 16.0. Defaults to 1.0.
+
+       saturation
+	   Saturation gain, between 0.0 and 16.0. Defaults to 1.0.
+
+       hue Hue shift in radians, between "-3.14" and 3.14. Defaults to 0.0.
+	   This will rotate the UV subvector, defaulting to BT.709
+	   coefficients for RGB inputs.
+
+       gamma
+	   Gamma adjustment, between 0.0 and 16.0. Defaults to 1.0.
+
+       cones
+	   Cone model to use for color blindness simulation. Accepts any
+	   combination of "l", "m" and "s". Here are some examples:
+
+	   m   Deuteranomaly / deuteranopia (affecting 3%-4% of the
+	       population)
+
+	   l   Protanomaly / protanopia (affecting 1%-2% of the population)
+
+	   l+m Monochromacy (very rare)
+
+	   l+m+s
+	       Achromatopsy (complete loss of daytime vision, extremely rare)
+
+       cone-strength
+	   Gain factor for the cones specified by "cones", between 0.0 and
+	   10.0. A value of 1.0 results in no change to color vision. A value
+	   of 0.0 (the default) simulates complete loss of those cones. Values
+	   above 1.0 result in exaggerating the differences between cones,
+	   which may help compensate for reduced color vision.
+
+       Peak detection
+
+       To help deal with sources that only have static HDR10 metadata (or no
+       tagging whatsoever), libplacebo uses its own internal frame analysis
+       compute shader to analyze source frames and adapt the tone mapping
+       function in realtime. If this is too slow, or if exactly reproducible
+       frame-perfect results are needed, it's recommended to turn this feature
+       off.
+
+       peak_detect
+	   Enable HDR peak detection. Ignores static MaxCLL/MaxFALL values in
+	   favor of dynamic detection from the input. Note that the detected
+	   values do not get written back to the output frames, they merely
+	   guide the internal tone mapping process. Enabled by default.
+
+       smoothing_period
+	   Peak detection smoothing period, between 0.0 and 1000.0. Higher
+	   values result in peak detection becoming less responsive to changes
+	   in the input. Defaults to 100.0.
+
+       minimum_peak
+	   Lower bound on the detected peak (relative to SDR white), between
+	   0.0 and 100.0. Defaults to 1.0.
+
+       scene_threshold_low
+       scene_threshold_high
+	   Lower and upper thresholds for scene change detection. Expressed in
+	   a logarithmic scale between 0.0 and 100.0. Default to 5.5 and 10.0,
+	   respectively. Setting either to a negative value disables this
+	   functionality.
+
+       overshoot
+	   Peak smoothing overshoot margin, between 0.0 and 1.0. Provides a
+	   safety margin to prevent clipping as a result of peak smoothing.
+	   Defaults to 0.05, corresponding to a margin of 5%.
+
+       Tone mapping
+
+       The options in this section control how libplacebo performs tone-
+       mapping and gamut-mapping when dealing with mismatches between wide-
+       gamut or HDR content.  In general, libplacebo relies on accurate source
+       tagging and mastering display gamut information to produce the best
+       results.
+
+       intent
+	   Rendering intent to use when adapting between different primary
+	   color gamuts (after tone-mapping).
+
+	   perceptual
+	       Perceptual gamut mapping. Currently equivalent to relative
+	       colorimetric.
+
+	   relative
+	       Relative colorimetric. This is the default.
+
+	   absolute
+	       Absolute colorimetric.
+
+	   saturation
+	       Saturation mapping. Forcibly stretches the source gamut to the
+	       target gamut.
+
+       gamut_mode
+	   How to handle out-of-gamut colors that can occur as a result of
+	   colorimetric gamut mapping.
+
+	   clip
+	       Do nothing, simply clip out-of-range colors to the RGB volume.
+	       This is the default.
+
+	   warn
+	       Highlight out-of-gamut pixels (by coloring them pink).
+
+	   darken
+	       Linearly reduces content brightness to preserves saturated
+	       details, followed by clipping the remaining out-of-gamut
+	       colors. As the name implies, this makes everything darker, but
+	       provides a good balance between preserving details and colors.
+
+	   desaturate
+	       Hard-desaturates out-of-gamut colors towards white, while
+	       preserving the luminance. Has a tendency to shift colors.
+
+       tonemapping
+	   Tone-mapping algorithm to use. Available values are:
+
+	   auto
+	       Automatic selection based on internal heuristics. This is the
+	       default.
+
+	   clip
+	       Performs no tone-mapping, just clips out-of-range colors.
+	       Retains perfect color accuracy for in-range colors but
+	       completely destroys out-of-range information.  Does not perform
+	       any black point adaptation. Not configurable.
+
+	   st2094-40
+	       EETF from SMPTE ST 2094-40 Annex B, which applies the Bezier
+	       curves from HDR10+ dynamic metadata based on Bezier curves to
+	       perform tone-mapping. The OOTF used is adjusted based on the
+	       ratio between the targeted and actual display peak luminances.
+
+	   st2094-10
+	       EETF from SMPTE ST 2094-10 Annex B.2, which takes into account
+	       the input signal average luminance in addition to the
+	       maximum/minimum. The configurable contrast parameter influences
+	       the slope of the linear output segment, defaulting to 1.0 for
+	       no increase/decrease in contrast. Note that this does not
+	       currently include the subjective gain/offset/gamma controls
+	       defined in Annex B.3.
+
+	   bt.2390
+	       EETF from the ITU-R Report BT.2390, a hermite spline roll-off
+	       with linear segment. The knee point offset is configurable.
+	       Note that this parameter defaults to 1.0, rather than the value
+	       of 0.5 from the ITU-R spec.
+
+	   bt.2446a
+	       EETF from ITU-R Report BT.2446, method A. Designed for well-
+	       mastered HDR sources. Can be used for both forward and inverse
+	       tone mapping. Not configurable.
+
+	   spline
+	       Simple spline consisting of two polynomials, joined by a single
+	       pivot point.  The parameter gives the pivot point (in PQ
+	       space), defaulting to 0.30.  Can be used for both forward and
+	       inverse tone mapping.
+
+	   reinhard
+	       Simple non-linear, global tone mapping algorithm. The parameter
+	       specifies the local contrast coefficient at the display peak.
+	       Essentially, a parameter of 0.5 implies that the reference
+	       white will be about half as bright as when clipping. Defaults
+	       to 0.5, which results in the simplest formulation of this
+	       function.
+
+	   mobius
+	       Generalization of the reinhard tone mapping algorithm to
+	       support an additional linear slope near black. The tone mapping
+	       parameter indicates the trade-off between the linear section
+	       and the non-linear section. Essentially, for a given parameter
+	       x, every color value below x will be mapped linearly, while
+	       higher values get non-linearly tone-mapped. Values near 1.0
+	       make this curve behave like "clip", while values near 0.0 make
+	       this curve behave like "reinhard". The default value is 0.3,
+	       which provides a good balance between colorimetric accuracy and
+	       preserving out-of-gamut details.
+
+	   hable
+	       Piece-wise, filmic tone-mapping algorithm developed by John
+	       Hable for use in Uncharted 2, inspired by a similar tone-
+	       mapping algorithm used by Kodak.  Popularized by its use in
+	       video games with HDR rendering. Preserves both dark and bright
+	       details very well, but comes with the drawback of changing the
+	       average brightness quite significantly. This is sort of similar
+	       to "reinhard" with parameter 0.24.
+
+	   gamma
+	       Fits a gamma (power) function to transfer between the source
+	       and target color spaces, effectively resulting in a perceptual
+	       hard-knee joining two roughly linear sections. This preserves
+	       details at all scales fairly accurately, but can result in an
+	       image with a muted or dull appearance. The parameter is used as
+	       the cutoff point, defaulting to 0.5.
+
+	   linear
+	       Linearly stretches the input range to the output range, in PQ
+	       space. This will preserve all details accurately, but results
+	       in a significantly different average brightness. Can be used
+	       for inverse tone-mapping in addition to regular tone-mapping.
+	       The parameter can be used as an additional linear gain
+	       coefficient (defaulting to 1.0).
+
+       tonemapping_param
+	   For tunable tone mapping functions, this parameter can be used to
+	   fine-tune the curve behavior. Refer to the documentation of
+	   "tonemapping". The default value of 0.0 is replaced by the curve's
+	   preferred default setting.
+
+       tonemapping_mode
+	   This option determines how the tone mapping function specified by
+	   "tonemapping" is applied to the colors in a scene. Possible values
+	   are:
+
+	   auto
+	       Automatic selection based on internal heuristics. This is the
+	       default.
+
+	   rgb Apply the function per-channel in the RGB colorspace.  Per-
+	       channel tone-mapping in RGB. Guarantees no clipping and heavily
+	       desaturates the output, but distorts the colors quite
+	       significantly. Very similar to the "Hollywood" look and feel.
+
+	   max Tone-mapping is performed on the brightest component found in
+	       the signal. Good at preserving details in highlights, but has a
+	       tendency to crush blacks.
+
+	   hybrid
+	       Tone-map per-channel for highlights and linearly (luma-based)
+	       for midtones/shadows, based on a fixed gamma 2.4 coefficient
+	       curve.
+
+	   luma
+	       Tone-map linearly on the luma component (CIE Y), and adjust
+	       (desaturate) the chromaticities to compensate using a simple
+	       constant factor. This is essentially the mode used in ITU-R
+	       BT.2446 method A.
+
+       inverse_tonemapping
+	   If enabled, this filter will also attempt stretching SDR signals to
+	   fill HDR output color volumes. Disabled by default.
+
+       tonemapping_crosstalk
+	   Extra tone-mapping crosstalk factor, between 0.0 and 0.3. This can
+	   help reduce issues tone-mapping certain bright spectral colors.
+	   Defaults to 0.04.
+
+       tonemapping_lut_size
+	   Size of the tone-mapping LUT, between 2 and 1024. Defaults to 256.
+	   Note that this figure is squared when combined with "peak_detect".
+
+       Dithering
+
+       By default, libplacebo will dither whenever necessary, which includes
+       rendering to any integer format below 16-bit precision. It's
+       recommended to always leave this on, since not doing so may result in
+       visible banding in the output, even if the "debanding" filter is
+       enabled. If maximum performance is needed, use "ordered_fixed" instead
+       of disabling dithering.
+
+       dithering
+	   Dithering method to use. Accepts the following values:
+
+	   none
+	       Disables dithering completely. May result in visible banding.
+
+	   blue
+	       Dither with pseudo-blue noise. This is the default.
+
+	   ordered
+	       Tunable ordered dither pattern.
+
+	   ordered_fixed
+	       Faster ordered dither with a fixed size of 6. Texture-less.
+
+	   white
+	       Dither with white noise. Texture-less.
+
+       dither_lut_size
+	   Dither LUT size, as log base2 between 1 and 8. Defaults to 6,
+	   corresponding to a LUT size of "64x64".
+
+       dither_temporal
+	   Enables temporal dithering. Disabled by default.
+
+       Custom shaders
+
+       libplacebo supports a number of custom shaders based on the mpv .hook
+       GLSL syntax. A collection of such shaders can be found here:
+       <https://github.com/mpv-player/mpv/wiki/User-Scripts#user-shaders>
+
+       A full description of the mpv shader format is beyond the scope of this
+       section, but a summary can be found here:
+       <https://mpv.io/manual/master/#options-glsl-shader>
+
+       custom_shader_path
+	   Specifies a path to a custom shader file to load at runtime.
+
+       custom_shader_bin
+	   Specifies a complete custom shader as a raw string.
+
+       Debugging / performance
+
+       All of the options in this section default off. They may be of
+       assistance when attempting to squeeze the maximum performance at the
+       cost of quality.
+
+       skip_aa
+	   Disable anti-aliasing when downscaling.
+
+       polar_cutoff
+	   Truncate polar (EWA) scaler kernels below this absolute magnitude,
+	   between 0.0 and 1.0.
+
+       disable_linear
+	   Disable linear light scaling.
+
+       disable_builtin
+	   Disable built-in GPU sampling (forces LUT).
+
+       force_icc_lut
+	   Force the use of a full ICC 3DLUT for gamut mapping.
+
+       disable_fbos
+	   Forcibly disable FBOs, resulting in loss of almost all
+	   functionality, but offering the maximum possible speed.
+
+       Commands
+
+       This filter supports almost all of the above options as commands.
+
+       Examples
+
+       o   Complete example for how to initialize the Vulkan device, upload
+	   frames to the GPU, perform filter conversion to yuv420p, and
+	   download frames back to the CPU for output. Note that in specific
+	   cases you can get around the need to perform format conversion by
+	   specifying the correct "format" filter option corresponding to the
+	   input frames.
+
+		   ffmpeg -i $INPUT -init_hw_device vulkan -vf hwupload,libplacebo=format=yuv420p,hwdownload,format=yuv420p $OUTPUT
+
+       o   Tone-map input to standard gamut BT.709 output:
+
+		   libplacebo=colorspace=bt709:color_primaries=bt709:color_trc=bt709:range=tv
+
+       o   Rescale input to fit into standard 1080p, with high quality
+	   scaling:
+
+		   libplacebo=w=1920:h=1080:force_original_aspect_ratio=decrease:normalize_sar=true:upscaler=ewa_lanczos:downscaler=ewa_lanczos
+
+       o   Convert input to standard sRGB JPEG:
+
+		   libplacebo=format=yuv420p:colorspace=bt470bg:color_primaries=bt709:color_trc=iec61966-2-1:range=pc
+
+       o   Use higher quality debanding settings:
+
+		   libplacebo=deband=true:deband_iterations=3:deband_radius=8:deband_threshold=6
+
+       o   Run this filter on the CPU, on systems with Mesa installed (and
+	   with the most expensive options disabled):
+
+		   ffmpeg ... -init_hw_device vulkan:llvmpipe ... -vf libplacebo=upscaler=none:downscaler=none:peak_detect=false
+
+       o   Suppress CPU-based AV1/H.274 film grain application in the decoder,
+	   in favor of doing it with this filter. Note that this is only a
+	   gain if the frames are either already on the GPU, or if you're
+	   using libplacebo for other purposes, since otherwise the VRAM
+	   roundtrip will more than offset any expected speedup.
+
+		   ffmpeg -export_side_data +film_grain ... -vf libplacebo=apply_filmgrain=true
+
+   libvmaf
+       Calulate the VMAF (Video Multi-Method Assessment Fusion) score for a
+       reference/distorted pair of input videos.
+
+       The first input is the distorted video, and the second input is the
+       reference video.
+
+       The obtained VMAF score is printed through the logging system.
+
+       It requires Netflix's vmaf library (libvmaf) as a pre-requisite.  After
+       installing the library it can be enabled using: "./configure
+       --enable-libvmaf".
+
+       The filter has following options:
+
+       model
+	   A `|` delimited list of vmaf models. Each model can be configured
+	   with a number of parameters.  Default value: "version=vmaf_v0.6.1"
+
+       model_path
+	   Deprecated, use model='path=...'.
+
+       enable_transform
+	   Deprecated, use model='enable_transform=true'.
+
+       phone_model
+	   Deprecated, use model='enable_transform=true'.
+
+       enable_conf_interval
+	   Deprecated, use model='enable_conf_interval=true'.
+
+       feature
+	   A `|` delimited list of features. Each feature can be configured
+	   with a number of parameters.
+
+       psnr
+	   Deprecated, use feature='name=psnr'.
+
+       ssim
+	   Deprecated, use feature='name=ssim'.
+
+       ms_ssim
+	   Deprecated, use feature='name=ms_ssim'.
+
+       log_path
+	   Set the file path to be used to store log files.
+
+       log_fmt
+	   Set the format of the log file (xml, json, csv, or sub).
+
+       n_threads
+	   Set number of threads to be used when initializing libvmaf.
+	   Default value: 0, no threads.
+
+       n_subsample
+	   Set frame subsampling interval to be used.
+
+       This filter also supports the framesync options.
+
+       Examples
+
+       o   In the examples below, a distorted video distorted.mpg is compared
+	   with a reference file reference.mpg.
+
+       o   Basic usage:
+
+		   ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf=log_path=output.xml -f null -
+
+       o   Example with multiple models:
+
+		   ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf='model=version=vmaf_v0.6.1\\:name=vmaf|version=vmaf_v0.6.1neg\\:name=vmaf_neg' -f null -
+
+       o   Example with multiple addtional features:
+
+		   ffmpeg -i distorted.mpg -i reference.mpg -lavfi libvmaf='feature=name=psnr|name=ciede' -f null -
+
+       o   Example with options and different containers:
+
+		   ffmpeg -i distorted.mpg -i reference.mkv -lavfi "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]libvmaf=log_fmt=json:log_path=output.json" -f null -
+
+   limitdiff
+       Apply limited difference filter using second and optionally third video
+       stream.
+
+       The filter accepts the following options:
+
+       threshold
+	   Set the threshold to use when allowing certain differences between
+	   video streams.  Any absolute difference value lower or exact than
+	   this threshold will pick pixel components from first video stream.
+
+       elasticity
+	   Set the elasticity of soft thresholding when processing video
+	   streams.  This value multiplied with first one sets second
+	   threshold.  Any absolute difference value greater or exact than
+	   second threshold will pick pixel components from second video
+	   stream. For values between those two threshold linear interpolation
+	   between first and second video stream will be used.
+
+       reference
+	   Enable the reference (third) video stream processing. By default is
+	   disabled.  If set, this video stream will be used for calculating
+	   absolute difference with first video stream.
+
+       planes
+	   Specify which planes will be processed. Defaults to all available.
+
+       Commands
+
+       This filter supports the all above options as commands except option
+       reference.
+
+   limiter
+       Limits the pixel components values to the specified range [min, max].
+
+       The filter accepts the following options:
+
+       min Lower bound. Defaults to the lowest allowed value for the input.
+
+       max Upper bound. Defaults to the highest allowed value for the input.
+
+       planes
+	   Specify which planes will be processed. Defaults to all available.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   loop
+       Loop video frames.
+
+       The filter accepts the following options:
+
+       loop
+	   Set the number of loops. Setting this value to -1 will result in
+	   infinite loops.  Default is 0.
+
+       size
+	   Set maximal size in number of frames. Default is 0.
+
+       start
+	   Set first frame of loop. Default is 0.
+
+       Examples
+
+       o   Loop single first frame infinitely:
+
+		   loop=loop=-1:size=1:start=0
+
+       o   Loop single first frame 10 times:
+
+		   loop=loop=10:size=1:start=0
+
+       o   Loop 10 first frames 5 times:
+
+		   loop=loop=5:size=10:start=0
+
+   lut1d
+       Apply a 1D LUT to an input video.
+
+       The filter accepts the following options:
+
+       file
+	   Set the 1D LUT file name.
+
+	   Currently supported formats:
+
+	   cube
+	       Iridas
+
+	   csp cineSpace
+
+       interp
+	   Select interpolation mode.
+
+	   Available values are:
+
+	   nearest
+	       Use values from the nearest defined point.
+
+	   linear
+	       Interpolate values using the linear interpolation.
+
+	   cosine
+	       Interpolate values using the cosine interpolation.
+
+	   cubic
+	       Interpolate values using the cubic interpolation.
+
+	   spline
+	       Interpolate values using the spline interpolation.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   lut3d
+       Apply a 3D LUT to an input video.
+
+       The filter accepts the following options:
+
+       file
+	   Set the 3D LUT file name.
+
+	   Currently supported formats:
+
+	   3dl AfterEffects
+
+	   cube
+	       Iridas
+
+	   dat DaVinci
+
+	   m3d Pandora
+
+	   csp cineSpace
+
+       interp
+	   Select interpolation mode.
+
+	   Available values are:
+
+	   nearest
+	       Use values from the nearest defined point.
+
+	   trilinear
+	       Interpolate values using the 8 points defining a cube.
+
+	   tetrahedral
+	       Interpolate values using a tetrahedron.
+
+	   pyramid
+	       Interpolate values using a pyramid.
+
+	   prism
+	       Interpolate values using a prism.
+
+       Commands
+
+       This filter supports the "interp" option as commands.
+
+   lumakey
+       Turn certain luma values into transparency.
+
+       The filter accepts the following options:
+
+       threshold
+	   Set the luma which will be used as base for transparency.  Default
+	   value is 0.
+
+       tolerance
+	   Set the range of luma values to be keyed out.  Default value is
+	   0.01.
+
+       softness
+	   Set the range of softness. Default value is 0.  Use this to control
+	   gradual transition from zero to full transparency.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   lut, lutrgb, lutyuv
+       Compute a look-up table for binding each pixel component input value to
+       an output value, and apply it to the input video.
+
+       lutyuv applies a lookup table to a YUV input video, lutrgb to an RGB
+       input video.
+
+       These filters accept the following parameters:
+
+       c0  set first pixel component expression
+
+       c1  set second pixel component expression
+
+       c2  set third pixel component expression
+
+       c3  set fourth pixel component expression, corresponds to the alpha
+	   component
+
+       r   set red component expression
+
+       g   set green component expression
+
+       b   set blue component expression
+
+       a   alpha component expression
+
+       y   set Y/luminance component expression
+
+       u   set U/Cb component expression
+
+       v   set V/Cr component expression
+
+       Each of them specifies the expression to use for computing the lookup
+       table for the corresponding pixel component values.
+
+       The exact component associated to each of the c* options depends on the
+       format in input.
+
+       The lut filter requires either YUV or RGB pixel formats in input,
+       lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
+
+       The expressions can contain the following constants and functions:
+
+       w
+       h   The input width and height.
+
+       val The input value for the pixel component.
+
+       clipval
+	   The input value, clipped to the minval-maxval range.
+
+       maxval
+	   The maximum value for the pixel component.
+
+       minval
+	   The minimum value for the pixel component.
+
+       negval
+	   The negated value for the pixel component value, clipped to the
+	   minval-maxval range; it corresponds to the expression
+	   "maxval-clipval+minval".
+
+       clip(val)
+	   The computed value in val, clipped to the minval-maxval range.
+
+       gammaval(gamma)
+	   The computed gamma correction value of the pixel component value,
+	   clipped to the minval-maxval range. It corresponds to the
+	   expression
+	   "pow((clipval-minval)/(maxval-minval)\,gamma)*(maxval-minval)+minval"
+
+       All expressions default to "clipval".
+
+       Commands
+
+       This filter supports same commands as options.
+
+       Examples
+
+       o   Negate input video:
+
+		   lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
+		   lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
+
+	   The above is the same as:
+
+		   lutrgb="r=negval:g=negval:b=negval"
+		   lutyuv="y=negval:u=negval:v=negval"
+
+       o   Negate luminance:
+
+		   lutyuv=y=negval
+
+       o   Remove chroma components, turning the video into a graytone image:
+
+		   lutyuv="u=128:v=128"
+
+       o   Apply a luma burning effect:
+
+		   lutyuv="y=2*val"
+
+       o   Remove green and blue components:
+
+		   lutrgb="g=0:b=0"
+
+       o   Set a constant alpha channel value on input:
+
+		   format=rgba,lutrgb=a="maxval-minval/2"
+
+       o   Correct luminance gamma by a factor of 0.5:
+
+		   lutyuv=y=gammaval(0.5)
+
+       o   Discard least significant bits of luma:
+
+		   lutyuv=y='bitand(val, 128+64+32)'
+
+       o   Technicolor like effect:
+
+		   lutyuv=u='(val-maxval/2)*2+maxval/2':v='(val-maxval/2)*2+maxval/2'
+
+   lut2, tlut2
+       The "lut2" filter takes two input streams and outputs one stream.
+
+       The "tlut2" (time lut2) filter takes two consecutive frames from one
+       single stream.
+
+       This filter accepts the following parameters:
+
+       c0  set first pixel component expression
+
+       c1  set second pixel component expression
+
+       c2  set third pixel component expression
+
+       c3  set fourth pixel component expression, corresponds to the alpha
+	   component
+
+       d   set output bit depth, only available for "lut2" filter. By default
+	   is 0, which means bit depth is automatically picked from first
+	   input format.
+
+       The "lut2" filter also supports the framesync options.
+
+       Each of them specifies the expression to use for computing the lookup
+       table for the corresponding pixel component values.
+
+       The exact component associated to each of the c* options depends on the
+       format in inputs.
+
+       The expressions can contain the following constants:
+
+       w
+       h   The input width and height.
+
+       x   The first input value for the pixel component.
+
+       y   The second input value for the pixel component.
+
+       bdx The first input video bit depth.
+
+       bdy The second input video bit depth.
+
+       All expressions default to "x".
+
+       Commands
+
+       This filter supports the all above options as commands except option
+       "d".
+
+       Examples
+
+       o   Highlight differences between two RGB video streams:
+
+		   lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,0,pow(2,bdx)-1)'
+
+       o   Highlight differences between two YUV video streams:
+
+		   lut2='ifnot(x-y,0,pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1):ifnot(x-y,pow(2,bdx-1),pow(2,bdx)-1)'
+
+       o   Show max difference between two video streams:
+
+		   lut2='if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1))):if(lt(x,y),0,if(gt(x,y),pow(2,bdx)-1,pow(2,bdx-1)))'
+
+   maskedclamp
+       Clamp the first input stream with the second input and third input
+       stream.
+
+       Returns the value of first stream to be between second input stream -
+       "undershoot" and third input stream + "overshoot".
+
+       This filter accepts the following options:
+
+       undershoot
+	   Default value is 0.
+
+       overshoot
+	   Default value is 0.
+
+       planes
+	   Set which planes will be processed as bitmap, unprocessed planes
+	   will be copied from first stream.  By default value 0xf, all planes
+	   will be processed.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   maskedmax
+       Merge the second and third input stream into output stream using
+       absolute differences between second input stream and first input stream
+       and absolute difference between third input stream and first input
+       stream. The picked value will be from second input stream if second
+       absolute difference is greater than first one or from third input
+       stream otherwise.
+
+       This filter accepts the following options:
+
+       planes
+	   Set which planes will be processed as bitmap, unprocessed planes
+	   will be copied from first stream.  By default value 0xf, all planes
+	   will be processed.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   maskedmerge
+       Merge the first input stream with the second input stream using per
+       pixel weights in the third input stream.
+
+       A value of 0 in the third stream pixel component means that pixel
+       component from first stream is returned unchanged, while maximum value
+       (eg. 255 for 8-bit videos) means that pixel component from second
+       stream is returned unchanged. Intermediate values define the amount of
+       merging between both input stream's pixel components.
+
+       This filter accepts the following options:
+
+       planes
+	   Set which planes will be processed as bitmap, unprocessed planes
+	   will be copied from first stream.  By default value 0xf, all planes
+	   will be processed.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   maskedmin
+       Merge the second and third input stream into output stream using
+       absolute differences between second input stream and first input stream
+       and absolute difference between third input stream and first input
+       stream. The picked value will be from second input stream if second
+       absolute difference is less than first one or from third input stream
+       otherwise.
+
+       This filter accepts the following options:
+
+       planes
+	   Set which planes will be processed as bitmap, unprocessed planes
+	   will be copied from first stream.  By default value 0xf, all planes
+	   will be processed.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   maskedthreshold
+       Pick pixels comparing absolute difference of two video streams with
+       fixed threshold.
+
+       If absolute difference between pixel component of first and second
+       video stream is equal or lower than user supplied threshold than pixel
+       component from first video stream is picked, otherwise pixel component
+       from second video stream is picked.
+
+       This filter accepts the following options:
+
+       threshold
+	   Set threshold used when picking pixels from absolute difference
+	   from two input video streams.
+
+       planes
+	   Set which planes will be processed as bitmap, unprocessed planes
+	   will be copied from second stream.  By default value 0xf, all
+	   planes will be processed.
+
+       mode
+	   Set mode of filter operation. Can be "abs" or "diff".  Default is
+	   "abs".
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   maskfun
+       Create mask from input video.
+
+       For example it is useful to create motion masks after "tblend" filter.
+
+       This filter accepts the following options:
+
+       low Set low threshold. Any pixel component lower or exact than this
+	   value will be set to 0.
+
+       high
+	   Set high threshold. Any pixel component higher than this value will
+	   be set to max value allowed for current pixel format.
+
+       planes
+	   Set planes to filter, by default all available planes are filtered.
+
+       fill
+	   Fill all frame pixels with this value.
+
+       sum Set max average pixel value for frame. If sum of all pixel
+	   components is higher that this average, output frame will be
+	   completely filled with value set by fill option.  Typically useful
+	   for scene changes when used in combination with "tblend" filter.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   mcdeint
+       Apply motion-compensation deinterlacing.
+
+       It needs one field per frame as input and must thus be used together
+       with yadif=1/3 or equivalent.
+
+       This filter is only available in ffmpeg version 4.4 or earlier.
+
+       This filter accepts the following options:
+
+       mode
+	   Set the deinterlacing mode.
+
+	   It accepts one of the following values:
+
+	   fast
+	   medium
+	   slow
+	       use iterative motion estimation
+
+	   extra_slow
+	       like slow, but use multiple reference frames.
+
+	   Default value is fast.
+
+       parity
+	   Set the picture field parity assumed for the input video. It must
+	   be one of the following values:
+
+	   0, tff
+	       assume top field first
+
+	   1, bff
+	       assume bottom field first
+
+	   Default value is bff.
+
+       qp  Set per-block quantization parameter (QP) used by the internal
+	   encoder.
+
+	   Higher values should result in a smoother motion vector field but
+	   less optimal individual vectors. Default value is 1.
+
+   median
+       Pick median pixel from certain rectangle defined by radius.
+
+       This filter accepts the following options:
+
+       radius
+	   Set horizontal radius size. Default value is 1.  Allowed range is
+	   integer from 1 to 127.
+
+       planes
+	   Set which planes to process. Default is 15, which is all available
+	   planes.
+
+       radiusV
+	   Set vertical radius size. Default value is 0.  Allowed range is
+	   integer from 0 to 127.  If it is 0, value will be picked from
+	   horizontal "radius" option.
+
+       percentile
+	   Set median percentile. Default value is 0.5.  Default value of 0.5
+	   will pick always median values, while 0 will pick minimum values,
+	   and 1 maximum values.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+   mergeplanes
+       Merge color channel components from several video streams.
+
+       The filter accepts up to 4 input streams, and merge selected input
+       planes to the output video.
+
+       This filter accepts the following options:
+
+       mapping
+	   Set input to output plane mapping. Default is 0.
+
+	   The mappings is specified as a bitmap. It should be specified as a
+	   hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. 'Aa' describes the
+	   mapping for the first plane of the output stream. 'A' sets the
+	   number of the input stream to use (from 0 to 3), and 'a' the plane
+	   number of the corresponding input to use (from 0 to 3). The rest of
+	   the mappings is similar, 'Bb' describes the mapping for the output
+	   stream second plane, 'Cc' describes the mapping for the output
+	   stream third plane and 'Dd' describes the mapping for the output
+	   stream fourth plane.
+
+       format
+	   Set output pixel format. Default is "yuva444p".
+
+       map0s
+       map1s
+       map2s
+       map3s
+	   Set input to output stream mapping for output Nth plane. Default is
+	   0.
+
+       map0p
+       map1p
+       map2p
+       map3p
+	   Set input to output plane mapping for output Nth plane. Default is
+	   0.
+
+       Examples
+
+       o   Merge three gray video streams of same width and height into single
+	   video stream:
+
+		   [a0][a1][a2]mergeplanes=0x001020:yuv444p
+
+       o   Merge 1st yuv444p stream and 2nd gray video stream into yuva444p
+	   video stream:
+
+		   [a0][a1]mergeplanes=0x00010210:yuva444p
+
+       o   Swap Y and A plane in yuva444p stream:
+
+		   format=yuva444p,mergeplanes=0x03010200:yuva444p
+
+       o   Swap U and V plane in yuv420p stream:
+
+		   format=yuv420p,mergeplanes=0x000201:yuv420p
+
+       o   Cast a rgb24 clip to yuv444p:
+
+		   format=rgb24,mergeplanes=0x000102:yuv444p
+
+   mestimate
+       Estimate and export motion vectors using block matching algorithms.
+       Motion vectors are stored in frame side data to be used by other
+       filters.
+
+       This filter accepts the following options:
+
+       method
+	   Specify the motion estimation method. Accepts one of the following
+	   values:
+
+	   esa Exhaustive search algorithm.
+
+	   tss Three step search algorithm.
+
+	   tdls
+	       Two dimensional logarithmic search algorithm.
+
+	   ntss
+	       New three step search algorithm.
+
+	   fss Four step search algorithm.
+
+	   ds  Diamond search algorithm.
+
+	   hexbs
+	       Hexagon-based search algorithm.
+
+	   epzs
+	       Enhanced predictive zonal search algorithm.
+
+	   umh Uneven multi-hexagon search algorithm.
+
+	   Default value is esa.
+
+       mb_size
+	   Macroblock size. Default 16.
+
+       search_param
+	   Search parameter. Default 7.
+
+   midequalizer
+       Apply Midway Image Equalization effect using two video streams.
+
+       Midway Image Equalization adjusts a pair of images to have the same
+       histogram, while maintaining their dynamics as much as possible. It's
+       useful for e.g. matching exposures from a pair of stereo cameras.
+
+       This filter has two inputs and one output, which must be of same pixel
+       format, but may be of different sizes. The output of filter is first
+       input adjusted with midway histogram of both inputs.
+
+       This filter accepts the following option:
+
+       planes
+	   Set which planes to process. Default is 15, which is all available
+	   planes.
+
+   minterpolate
+       Convert the video to specified frame rate using motion interpolation.
+
+       This filter accepts the following options:
+
+       fps Specify the output frame rate. This can be rational e.g.
+	   "60000/1001". Frames are dropped if fps is lower than source fps.
+	   Default 60.
+
+       mi_mode
+	   Motion interpolation mode. Following values are accepted:
+
+	   dup Duplicate previous or next frame for interpolating new ones.
+
+	   blend
+	       Blend source frames. Interpolated frame is mean of previous and
+	       next frames.
+
+	   mci Motion compensated interpolation. Following options are
+	       effective when this mode is selected:
+
+	       mc_mode
+		   Motion compensation mode. Following values are accepted:
+
+		   obmc
+		       Overlapped block motion compensation.
+
+		   aobmc
+		       Adaptive overlapped block motion compensation. Window
+		       weighting coefficients are controlled adaptively
+		       according to the reliabilities of the neighboring
+		       motion vectors to reduce oversmoothing.
+
+		   Default mode is obmc.
+
+	       me_mode
+		   Motion estimation mode. Following values are accepted:
+
+		   bidir
+		       Bidirectional motion estimation. Motion vectors are
+		       estimated for each source frame in both forward and
+		       backward directions.
+
+		   bilat
+		       Bilateral motion estimation. Motion vectors are
+		       estimated directly for interpolated frame.
+
+		   Default mode is bilat.
+
+	       me  The algorithm to be used for motion estimation. Following
+		   values are accepted:
+
+		   esa Exhaustive search algorithm.
+
+		   tss Three step search algorithm.
+
+		   tdls
+		       Two dimensional logarithmic search algorithm.
+
+		   ntss
+		       New three step search algorithm.
+
+		   fss Four step search algorithm.
+
+		   ds  Diamond search algorithm.
+
+		   hexbs
+		       Hexagon-based search algorithm.
+
+		   epzs
+		       Enhanced predictive zonal search algorithm.
+
+		   umh Uneven multi-hexagon search algorithm.
+
+		   Default algorithm is epzs.
+
+	       mb_size
+		   Macroblock size. Default 16.
+
+	       search_param
+		   Motion estimation search parameter. Default 32.
+
+	       vsbmc
+		   Enable variable-size block motion compensation. Motion
+		   estimation is applied with smaller block sizes at object
+		   boundaries in order to make the them less blur. Default is
+		   0 (disabled).
+
+       scd Scene change detection method. Scene change leads motion vectors to
+	   be in random direction. Scene change detection replace interpolated
+	   frames by duplicate ones. May not be needed for other modes.
+	   Following values are accepted:
+
+	   none
+	       Disable scene change detection.
+
+	   fdiff
+	       Frame difference. Corresponding pixel values are compared and
+	       if it satisfies scd_threshold scene change is detected.
+
+	   Default method is fdiff.
+
+       scd_threshold
+	   Scene change detection threshold. Default is 10..
+
+   mix
+       Mix several video input streams into one video stream.
+
+       A description of the accepted options follows.
+
+       inputs
+	   The number of inputs. If unspecified, it defaults to 2.
+
+       weights
+	   Specify weight of each input video stream as sequence.  Each weight
+	   is separated by space. If number of weights is smaller than number
+	   of frames last specified weight will be used for all remaining
+	   unset weights.
+
+       scale
+	   Specify scale, if it is set it will be multiplied with sum of each
+	   weight multiplied with pixel values to give final destination pixel
+	   value. By default scale is auto scaled to sum of weights.
+
+       planes
+	   Set which planes to filter. Default is all. Allowed range is from 0
+	   to 15.
+
+       duration
+	   Specify how end of stream is determined.
+
+	   longest
+	       The duration of the longest input. (default)
+
+	   shortest
+	       The duration of the shortest input.
+
+	   first
+	       The duration of the first input.
+
+       Commands
+
+       This filter supports the following commands:
+
+       weights
+       scale
+       planes
+	   Syntax is same as option with same name.
+
+   monochrome
+       Convert video to gray using custom color filter.
+
+       A description of the accepted options follows.
+
+       cb  Set the chroma blue spot. Allowed range is from -1 to 1.  Default
+	   value is 0.
+
+       cr  Set the chroma red spot. Allowed range is from -1 to 1.  Default
+	   value is 0.
+
+       size
+	   Set the color filter size. Allowed range is from .1 to 10.  Default
+	   value is 1.
+
+       high
+	   Set the highlights strength. Allowed range is from 0 to 1.  Default
+	   value is 0.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   morpho
+       This filter allows to apply main morphological grayscale transforms,
+       erode and dilate with arbitrary structures set in second input stream.
+
+       Unlike naive implementation and much slower performance in erosion and
+       dilation filters, when speed is critical "morpho" filter should be used
+       instead.
+
+       A description of accepted options follows,
+
+       mode
+	   Set morphological transform to apply, can be:
+
+	   erode
+	   dilate
+	   open
+	   close
+	   gradient
+	   tophat
+	   blackhat
+
+	   Default is "erode".
+
+       planes
+	   Set planes to filter, by default all planes except alpha are
+	   filtered.
+
+       structure
+	   Set which structure video frames will be processed from second
+	   input stream, can be first or all. Default is all.
+
+       The "morpho" filter also supports the framesync options.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   mpdecimate
+       Drop frames that do not differ greatly from the previous frame in order
+       to reduce frame rate.
+
+       The main use of this filter is for very-low-bitrate encoding (e.g.
+       streaming over dialup modem), but it could in theory be used for fixing
+       movies that were inverse-telecined incorrectly.
+
+       A description of the accepted options follows.
+
+       max Set the maximum number of consecutive frames which can be dropped
+	   (if positive), or the minimum interval between dropped frames (if
+	   negative). If the value is 0, the frame is dropped disregarding the
+	   number of previous sequentially dropped frames.
+
+	   Default value is 0.
+
+       hi
+       lo
+       frac
+	   Set the dropping threshold values.
+
+	   Values for hi and lo are for 8x8 pixel blocks and represent actual
+	   pixel value differences, so a threshold of 64 corresponds to 1 unit
+	   of difference for each pixel, or the same spread out differently
+	   over the block.
+
+	   A frame is a candidate for dropping if no 8x8 blocks differ by more
+	   than a threshold of hi, and if no more than frac blocks (1 meaning
+	   the whole image) differ by more than a threshold of lo.
+
+	   Default value for hi is 64*12, default value for lo is 64*5, and
+	   default value for frac is 0.33.
+
+   msad
+       Obtain the MSAD (Mean Sum of Absolute Differences) between two input
+       videos.
+
+       This filter takes two input videos.
+
+       Both input videos must have the same resolution and pixel format for
+       this filter to work correctly. Also it assumes that both inputs have
+       the same number of frames, which are compared one by one.
+
+       The obtained per component, average, min and max MSAD is printed
+       through the logging system.
+
+       The filter stores the calculated MSAD of each frame in frame metadata.
+
+       This filter also supports the framesync options.
+
+       In the below example the input file main.mpg being processed is
+       compared with the reference file ref.mpg.
+
+	       ffmpeg -i main.mpg -i ref.mpg -lavfi msad -f null -
+
+   multiply
+       Multiply first video stream pixels values with second video stream
+       pixels values.
+
+       The filter accepts the following options:
+
+       scale
+	   Set the scale applied to second video stream. By default is 1.
+	   Allowed range is from 0 to 9.
+
+       offset
+	   Set the offset applied to second video stream. By default is 0.5.
+	   Allowed range is from "-1" to 1.
+
+       planes
+	   Specify planes from input video stream that will be processed.  By
+	   default all planes are processed.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   negate
+       Negate (invert) the input video.
+
+       It accepts the following option:
+
+       components
+	   Set components to negate.
+
+	   Available values for components are:
+
+	   y
+	   u
+	   v
+	   a
+	   r
+	   g
+	   b
+       negate_alpha
+	   With value 1, it negates the alpha component, if present. Default
+	   value is 0.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   nlmeans
+       Denoise frames using Non-Local Means algorithm.
+
+       Each pixel is adjusted by looking for other pixels with similar
+       contexts. This context similarity is defined by comparing their
+       surrounding patches of size pxp. Patches are searched in an area of rxr
+       around the pixel.
+
+       Note that the research area defines centers for patches, which means
+       some patches will be made of pixels outside that research area.
+
+       The filter accepts the following options.
+
+       s   Set denoising strength. Default is 1.0. Must be in range [1.0,
+	   30.0].
+
+       p   Set patch size. Default is 7. Must be odd number in range [0, 99].
+
+       pc  Same as p but for chroma planes.
+
+	   The default value is 0 and means automatic.
+
+       r   Set research size. Default is 15. Must be odd number in range [0,
+	   99].
+
+       rc  Same as r but for chroma planes.
+
+	   The default value is 0 and means automatic.
+
+   nnedi
+       Deinterlace video using neural network edge directed interpolation.
+
+       This filter accepts the following options:
+
+       weights
+	   Mandatory option, without binary file filter can not work.
+	   Currently file can be found here:
+	   https://github.com/dubhater/vapoursynth-nnedi3/blob/master/src/nnedi3_weights.bin
+
+       deint
+	   Set which frames to deinterlace, by default it is "all".  Can be
+	   "all" or "interlaced".
+
+       field
+	   Set mode of operation.
+
+	   Can be one of the following:
+
+	   af  Use frame flags, both fields.
+
+	   a   Use frame flags, single field.
+
+	   t   Use top field only.
+
+	   b   Use bottom field only.
+
+	   tf  Use both fields, top first.
+
+	   bf  Use both fields, bottom first.
+
+       planes
+	   Set which planes to process, by default filter process all frames.
+
+       nsize
+	   Set size of local neighborhood around each pixel, used by the
+	   predictor neural network.
+
+	   Can be one of the following:
+
+	   s8x6
+	   s16x6
+	   s32x6
+	   s48x6
+	   s8x4
+	   s16x4
+	   s32x4
+       nns Set the number of neurons in predictor neural network.  Can be one
+	   of the following:
+
+	   n16
+	   n32
+	   n64
+	   n128
+	   n256
+       qual
+	   Controls the number of different neural network predictions that
+	   are blended together to compute the final output value. Can be
+	   "fast", default or "slow".
+
+       etype
+	   Set which set of weights to use in the predictor.  Can be one of
+	   the following:
+
+	   a, abs
+	       weights trained to minimize absolute error
+
+	   s, mse
+	       weights trained to minimize squared error
+
+       pscrn
+	   Controls whether or not the prescreener neural network is used to
+	   decide which pixels should be processed by the predictor neural
+	   network and which can be handled by simple cubic interpolation.
+	   The prescreener is trained to know whether cubic interpolation will
+	   be sufficient for a pixel or whether it should be predicted by the
+	   predictor nn.  The computational complexity of the prescreener nn
+	   is much less than that of the predictor nn. Since most pixels can
+	   be handled by cubic interpolation, using the prescreener generally
+	   results in much faster processing.  The prescreener is pretty
+	   accurate, so the difference between using it and not using it is
+	   almost always unnoticeable.
+
+	   Can be one of the following:
+
+	   none
+	   original
+	   new
+	   new2
+	   new3
+
+	   Default is "new".
+
+       Commands
+
+       This filter supports same commands as options, excluding weights
+       option.
+
+   noformat
+       Force libavfilter not to use any of the specified pixel formats for the
+       input to the next filter.
+
+       It accepts the following parameters:
+
+       pix_fmts
+	   A '|'-separated list of pixel format names, such as
+	   pix_fmts=yuv420p|monow|rgb24".
+
+       Examples
+
+       o   Force libavfilter to use a format different from yuv420p for the
+	   input to the vflip filter:
+
+		   noformat=pix_fmts=yuv420p,vflip
+
+       o   Convert the input video to any of the formats not contained in the
+	   list:
+
+		   noformat=yuv420p|yuv444p|yuv410p
+
+   noise
+       Add noise on video input frame.
+
+       The filter accepts the following options:
+
+       all_seed
+       c0_seed
+       c1_seed
+       c2_seed
+       c3_seed
+	   Set noise seed for specific pixel component or all pixel components
+	   in case of all_seed. Default value is 123457.
+
+       all_strength, alls
+       c0_strength, c0s
+       c1_strength, c1s
+       c2_strength, c2s
+       c3_strength, c3s
+	   Set noise strength for specific pixel component or all pixel
+	   components in case all_strength. Default value is 0. Allowed range
+	   is [0, 100].
+
+       all_flags, allf
+       c0_flags, c0f
+       c1_flags, c1f
+       c2_flags, c2f
+       c3_flags, c3f
+	   Set pixel component flags or set flags for all components if
+	   all_flags.  Available values for component flags are:
+
+	   a   averaged temporal noise (smoother)
+
+	   p   mix random noise with a (semi)regular pattern
+
+	   t   temporal noise (noise pattern changes between frames)
+
+	   u   uniform noise (gaussian otherwise)
+
+       Examples
+
+       Add temporal and uniform noise to input video:
+
+	       noise=alls=20:allf=t+u
+
+   normalize
+       Normalize RGB video (aka histogram stretching, contrast stretching).
+       See: https://en.wikipedia.org/wiki/Normalization_(image_processing)
+
+       For each channel of each frame, the filter computes the input range and
+       maps it linearly to the user-specified output range. The output range
+       defaults to the full dynamic range from pure black to pure white.
+
+       Temporal smoothing can be used on the input range to reduce flickering
+       (rapid changes in brightness) caused when small dark or bright objects
+       enter or leave the scene. This is similar to the auto-exposure
+       (automatic gain control) on a video camera, and, like a video camera,
+       it may cause a period of over- or under-exposure of the video.
+
+       The R,G,B channels can be normalized independently, which may cause
+       some color shifting, or linked together as a single channel, which
+       prevents color shifting. Linked normalization preserves hue.
+       Independent normalization does not, so it can be used to remove some
+       color casts. Independent and linked normalization can be combined in
+       any ratio.
+
+       The normalize filter accepts the following options:
+
+       blackpt
+       whitept
+	   Colors which define the output range. The minimum input value is
+	   mapped to the blackpt. The maximum input value is mapped to the
+	   whitept.  The defaults are black and white respectively. Specifying
+	   white for blackpt and black for whitept will give color-inverted,
+	   normalized video. Shades of grey can be used to reduce the dynamic
+	   range (contrast). Specifying saturated colors here can create some
+	   interesting effects.
+
+       smoothing
+	   The number of previous frames to use for temporal smoothing. The
+	   input range of each channel is smoothed using a rolling average
+	   over the current frame and the smoothing previous frames. The
+	   default is 0 (no temporal smoothing).
+
+       independence
+	   Controls the ratio of independent (color shifting) channel
+	   normalization to linked (color preserving) normalization. 0.0 is
+	   fully linked, 1.0 is fully independent. Defaults to 1.0 (fully
+	   independent).
+
+       strength
+	   Overall strength of the filter. 1.0 is full strength. 0.0 is a
+	   rather expensive no-op. Defaults to 1.0 (full strength).
+
+       Commands
+
+       This filter supports same commands as options, excluding smoothing
+       option.	The command accepts the same syntax of the corresponding
+       option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+       Examples
+
+       Stretch video contrast to use the full dynamic range, with no temporal
+       smoothing; may flicker depending on the source content:
+
+	       normalize=blackpt=black:whitept=white:smoothing=0
+
+       As above, but with 50 frames of temporal smoothing; flicker should be
+       reduced, depending on the source content:
+
+	       normalize=blackpt=black:whitept=white:smoothing=50
+
+       As above, but with hue-preserving linked channel normalization:
+
+	       normalize=blackpt=black:whitept=white:smoothing=50:independence=0
+
+       As above, but with half strength:
+
+	       normalize=blackpt=black:whitept=white:smoothing=50:independence=0:strength=0.5
+
+       Map the darkest input color to red, the brightest input color to cyan:
+
+	       normalize=blackpt=red:whitept=cyan
+
+   null
+       Pass the video source unchanged to the output.
+
+   ocr
+       Optical Character Recognition
+
+       This filter uses Tesseract for optical character recognition. To enable
+       compilation of this filter, you need to configure FFmpeg with
+       "--enable-libtesseract".
+
+       It accepts the following options:
+
+       datapath
+	   Set datapath to tesseract data. Default is to use whatever was set
+	   at installation.
+
+       language
+	   Set language, default is "eng".
+
+       whitelist
+	   Set character whitelist.
+
+       blacklist
+	   Set character blacklist.
+
+       The filter exports recognized text as the frame metadata
+       "lavfi.ocr.text".  The filter exports confidence of recognized words as
+       the frame metadata "lavfi.ocr.confidence".
+
+   ocv
+       Apply a video transform using libopencv.
+
+       To enable this filter, install the libopencv library and headers and
+       configure FFmpeg with "--enable-libopencv".
+
+       It accepts the following parameters:
+
+       filter_name
+	   The name of the libopencv filter to apply.
+
+       filter_params
+	   The parameters to pass to the libopencv filter. If not specified,
+	   the default values are assumed.
+
+       Refer to the official libopencv documentation for more precise
+       information:
+       <http://docs.opencv.org/master/modules/imgproc/doc/filtering.html>
+
+       Several libopencv filters are supported; see the following subsections.
+
+       dilate
+
+       Dilate an image by using a specific structuring element.  It
+       corresponds to the libopencv function "cvDilate".
+
+       It accepts the parameters: struct_el|nb_iterations.
+
+       struct_el represents a structuring element, and has the syntax:
+       colsxrows+anchor_xxanchor_y/shape
+
+       cols and rows represent the number of columns and rows of the
+       structuring element, anchor_x and anchor_y the anchor point, and shape
+       the shape for the structuring element. shape must be "rect", "cross",
+       "ellipse", or "custom".
+
+       If the value for shape is "custom", it must be followed by a string of
+       the form "=filename". The file with name filename is assumed to
+       represent a binary image, with each printable character corresponding
+       to a bright pixel. When a custom shape is used, cols and rows are
+       ignored, the number or columns and rows of the read file are assumed
+       instead.
+
+       The default value for struct_el is "3x3+0x0/rect".
+
+       nb_iterations specifies the number of times the transform is applied to
+       the image, and defaults to 1.
+
+       Some examples:
+
+	       # Use the default values
+	       ocv=dilate
+
+	       # Dilate using a structuring element with a 5x5 cross, iterating two times
+	       ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
+
+	       # Read the shape from the file diamond.shape, iterating two times.
+	       # The file diamond.shape may contain a pattern of characters like this
+	       #   *
+	       #  ***
+	       # *****
+	       #  ***
+	       #   *
+	       # The specified columns and rows are ignored
+	       # but the anchor point coordinates are not
+	       ocv=dilate:0x0+2x2/custom=diamond.shape|2
+
+       erode
+
+       Erode an image by using a specific structuring element.	It corresponds
+       to the libopencv function "cvErode".
+
+       It accepts the parameters: struct_el:nb_iterations, with the same
+       syntax and semantics as the dilate filter.
+
+       smooth
+
+       Smooth the input video.
+
+       The filter takes the following parameters:
+       type|param1|param2|param3|param4.
+
+       type is the type of smooth filter to apply, and must be one of the
+       following values: "blur", "blur_no_scale", "median", "gaussian", or
+       "bilateral". The default value is "gaussian".
+
+       The meaning of param1, param2, param3, and param4 depends on the smooth
+       type. param1 and param2 accept integer positive values or 0. param3 and
+       param4 accept floating point values.
+
+       The default value for param1 is 3. The default value for the other
+       parameters is 0.
+
+       These parameters correspond to the parameters assigned to the libopencv
+       function "cvSmooth".
+
+   oscilloscope
+       2D Video Oscilloscope.
+
+       Useful to measure spatial impulse, step responses, chroma delays, etc.
+
+       It accepts the following parameters:
+
+       x   Set scope center x position.
+
+       y   Set scope center y position.
+
+       s   Set scope size, relative to frame diagonal.
+
+       t   Set scope tilt/rotation.
+
+       o   Set trace opacity.
+
+       tx  Set trace center x position.
+
+       ty  Set trace center y position.
+
+       tw  Set trace width, relative to width of frame.
+
+       th  Set trace height, relative to height of frame.
+
+       c   Set which components to trace. By default it traces first three
+	   components.
+
+       g   Draw trace grid. By default is enabled.
+
+       st  Draw some statistics. By default is enabled.
+
+       sc  Draw scope. By default is enabled.
+
+       Commands
+
+       This filter supports same commands as options.  The command accepts the
+       same syntax of the corresponding option.
+
+       If the specified expression is not valid, it is kept at its current
+       value.
+
+       Examples
+
+       o   Inspect full first row of video frame.
+
+		   oscilloscope=x=0.5:y=0:s=1
+
+       o   Inspect full last row of video frame.
+
+		   oscilloscope=x=0.5:y=1:s=1
+
+       o   Inspect full 5th line of video frame of height 1080.
+
+		   oscilloscope=x=0.5:y=5/1080:s=1
+
+       o   Inspect full last column of video frame.
+
+		   oscilloscope=x=1:y=0.5:s=1:t=1
+
+   overlay
+       Overlay one video on top of another.
+
+       It takes two inputs and has one output. The first input is the "main"
+       video on which the second input is overlaid.
+
+       It accepts the following parameters:
+
+       A description of the accepted options follows.
+
+       x
+       y   Set the expression for the x and y coordinates of the overlaid
+	   video on the main video. Default value is "0" for both expressions.
+	   In case the expression is invalid, it is set to a huge value
+	   (meaning that the overlay will not be displayed within the output
+	   visible area).
+
+       eof_action
+	   See framesync.
+
+       eval
+	   Set when the expressions for x, and y are evaluated.
+
+	   It accepts the following values:
+
+	   init
+	       only evaluate expressions once during the filter initialization
+	       or when a command is processed
+
+	   frame
+	       evaluate expressions for each incoming frame
+
+	   Default value is frame.
+
+       shortest
+	   See framesync.
+
+       format
+	   Set the format for the output video.
+
+	   It accepts the following values:
+
+	   yuv420
+	       force YUV420 output
+
+	   yuv420p10
+	       force YUV420p10 output
+
+	   yuv422
+	       force YUV422 output
+
+	   yuv422p10
+	       force YUV422p10 output
+
+	   yuv444
+	       force YUV444 output
+
+	   rgb force packed RGB output
+
+	   gbrp
+	       force planar RGB output
+
+	   auto
+	       automatically pick format
+
+	   Default value is yuv420.
+
+       repeatlast
+	   See framesync.
+
+       alpha
+	   Set format of alpha of the overlaid video, it can be straight or
+	   premultiplied. Default is straight.
+
+       The x, and y expressions can contain the following parameters.
+
+       main_w, W
+       main_h, H
+	   The main input width and height.
+
+       overlay_w, w
+       overlay_h, h
+	   The overlay input width and height.
+
+       x
+       y   The computed values for x and y. They are evaluated for each new
+	   frame.
+
+       hsub
+       vsub
+	   horizontal and vertical chroma subsample values of the output
+	   format. For example for the pixel format "yuv422p" hsub is 2 and
+	   vsub is 1.
+
+       n   the number of input frame, starting from 0
+
+       pos the position in the file of the input frame, NAN if unknown
+
+       t   The timestamp, expressed in seconds. It's NAN if the input
+	   timestamp is unknown.
+
+       This filter also supports the framesync options.
+
+       Note that the n, pos, t variables are available only when evaluation is
+       done per frame, and will evaluate to NAN when eval is set to init.
+
+       Be aware that frames are taken from each input video in timestamp
+       order, hence, if their initial timestamps differ, it is a good idea to
+       pass the two inputs through a setpts=PTS-STARTPTS filter to have them
+       begin in the same zero timestamp, as the example for the movie filter
+       does.
+
+       You can chain together more overlays but you should test the efficiency
+       of such approach.
+
+       Commands
+
+       This filter supports the following commands:
+
+       x
+       y   Modify the x and y of the overlay input.  The command accepts the
+	   same syntax of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+       Examples
+
+       o   Draw the overlay at 10 pixels from the bottom right corner of the
+	   main video:
+
+		   overlay=main_w-overlay_w-10:main_h-overlay_h-10
+
+	   Using named options the example above becomes:
+
+		   overlay=x=main_w-overlay_w-10:y=main_h-overlay_h-10
+
+       o   Insert a transparent PNG logo in the bottom left corner of the
+	   input, using the ffmpeg tool with the "-filter_complex" option:
+
+		   ffmpeg -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output
+
+       o   Insert 2 different transparent PNG logos (second logo on bottom
+	   right corner) using the ffmpeg tool:
+
+		   ffmpeg -i input -i logo1 -i logo2 -filter_complex 'overlay=x=10:y=H-h-10,overlay=x=W-w-10:y=H-h-10' output
+
+       o   Add a transparent color layer on top of the main video; "WxH" must
+	   specify the size of the main input to the overlay filter:
+
+		   color=color=red@.3:size=WxH [over]; [in][over] overlay [out]
+
+       o   Play an original video and a filtered version (here with the
+	   deshake filter) side by side using the ffplay tool:
+
+		   ffplay input.avi -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]deshake[filt]; [src][filt]overlay=w'
+
+	   The above command is the same as:
+
+		   ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
+
+       o   Make a sliding overlay appearing from the left to the right top
+	   part of the screen starting since time 2:
+
+		   overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0
+
+       o   Compose output by putting two input videos side to side:
+
+		   ffmpeg -i left.avi -i right.avi -filter_complex "
+		   nullsrc=size=200x100 [background];
+		   [0:v] setpts=PTS-STARTPTS, scale=100x100 [left];
+		   [1:v] setpts=PTS-STARTPTS, scale=100x100 [right];
+		   [background][left]	    overlay=shortest=1	     [background+left];
+		   [background+left][right] overlay=shortest=1:x=100 [left+right]
+		   "
+
+       o   Mask 10-20 seconds of a video by applying the delogo filter to a
+	   section
+
+		   ffmpeg -i test.avi -codec:v:0 wmv2 -ar 11025 -b:v 9000k
+		   -vf '[in]split[split_main][split_delogo];[split_delogo]trim=start=360:end=371,delogo=0:0:640:480[delogoed];[split_main][delogoed]overlay=eof_action=pass[out]'
+		   masked.avi
+
+       o   Chain several overlays in cascade:
+
+		   nullsrc=s=200x200 [bg];
+		   testsrc=s=100x100, split=4 [in0][in1][in2][in3];
+		   [in0] lutrgb=r=0, [bg]   overlay=0:0     [mid0];
+		   [in1] lutrgb=g=0, [mid0] overlay=100:0   [mid1];
+		   [in2] lutrgb=b=0, [mid1] overlay=0:100   [mid2];
+		   [in3] null,	     [mid2] overlay=100:100 [out0]
+
+   overlay_cuda
+       Overlay one video on top of another.
+
+       This is the CUDA variant of the overlay filter.	It only accepts CUDA
+       frames. The underlying input pixel formats have to match.
+
+       It takes two inputs and has one output. The first input is the "main"
+       video on which the second input is overlaid.
+
+       It accepts the following parameters:
+
+       x
+       y   Set expressions for the x and y coordinates of the overlaid video
+	   on the main video.
+
+	   They can contain the following parameters:
+
+	   main_w, W
+	   main_h, H
+	       The main input width and height.
+
+	   overlay_w, w
+	   overlay_h, h
+	       The overlay input width and height.
+
+	   x
+	   y   The computed values for x and y. They are evaluated for each
+	       new frame.
+
+	   n   The ordinal index of the main input frame, starting from 0.
+
+	   pos The byte offset position in the file of the main input frame,
+	       NAN if unknown.
+
+	   t   The timestamp of the main input frame, expressed in seconds,
+	       NAN if unknown.
+
+	   Default value is "0" for both expressions.
+
+       eval
+	   Set when the expressions for x and y are evaluated.
+
+	   It accepts the following values:
+
+	   init
+	       Evaluate expressions once during filter initialization or when
+	       a command is processed.
+
+	   frame
+	       Evaluate expressions for each incoming frame
+
+	   Default value is frame.
+
+       eof_action
+	   See framesync.
+
+       shortest
+	   See framesync.
+
+       repeatlast
+	   See framesync.
+
+       This filter also supports the framesync options.
+
+   owdenoise
+       Apply Overcomplete Wavelet denoiser.
+
+       The filter accepts the following options:
+
+       depth
+	   Set depth.
+
+	   Larger depth values will denoise lower frequency components more,
+	   but slow down filtering.
+
+	   Must be an int in the range 8-16, default is 8.
+
+       luma_strength, ls
+	   Set luma strength.
+
+	   Must be a double value in the range 0-1000, default is 1.0.
+
+       chroma_strength, cs
+	   Set chroma strength.
+
+	   Must be a double value in the range 0-1000, default is 1.0.
+
+   pad
+       Add paddings to the input image, and place the original input at the
+       provided x, y coordinates.
+
+       It accepts the following parameters:
+
+       width, w
+       height, h
+	   Specify an expression for the size of the output image with the
+	   paddings added. If the value for width or height is 0, the
+	   corresponding input size is used for the output.
+
+	   The width expression can reference the value set by the height
+	   expression, and vice versa.
+
+	   The default value of width and height is 0.
+
+       x
+       y   Specify the offsets to place the input image at within the padded
+	   area, with respect to the top/left border of the output image.
+
+	   The x expression can reference the value set by the y expression,
+	   and vice versa.
+
+	   The default value of x and y is 0.
+
+	   If x or y evaluate to a negative number, they'll be changed so the
+	   input image is centered on the padded area.
+
+       color
+	   Specify the color of the padded area. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+
+	   The default value of color is "black".
+
+       eval
+	   Specify when to evaluate  width, height, x and y expression.
+
+	   It accepts the following values:
+
+	   init
+	       Only evaluate expressions once during the filter initialization
+	       or when a command is processed.
+
+	   frame
+	       Evaluate expressions for each incoming frame.
+
+	   Default value is init.
+
+       aspect
+	   Pad to aspect instead to a resolution.
+
+       The value for the width, height, x, and y options are expressions
+       containing the following constants:
+
+       in_w
+       in_h
+	   The input video width and height.
+
+       iw
+       ih  These are the same as in_w and in_h.
+
+       out_w
+       out_h
+	   The output width and height (the size of the padded area), as
+	   specified by the width and height expressions.
+
+       ow
+       oh  These are the same as out_w and out_h.
+
+       x
+       y   The x and y offsets as specified by the x and y expressions, or NAN
+	   if not yet specified.
+
+       a   same as iw / ih
+
+       sar input sample aspect ratio
+
+       dar input display aspect ratio, it is the same as (iw / ih) * sar
+
+       hsub
+       vsub
+	   The horizontal and vertical chroma subsample values. For example
+	   for the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       Examples
+
+       o   Add paddings with the color "violet" to the input video. The output
+	   video size is 640x480, and the top-left corner of the input video
+	   is placed at column 0, row 40
+
+		   pad=640:480:0:40:violet
+
+	   The example above is equivalent to the following command:
+
+		   pad=width=640:height=480:x=0:y=40:color=violet
+
+       o   Pad the input to get an output with dimensions increased by 3/2,
+	   and put the input video at the center of the padded area:
+
+		   pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
+
+       o   Pad the input to get a squared output with size equal to the
+	   maximum value between the input width and height, and put the input
+	   video at the center of the padded area:
+
+		   pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
+
+       o   Pad the input to get a final w/h ratio of 16:9:
+
+		   pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
+
+       o   In case of anamorphic video, in order to set the output display
+	   aspect correctly, it is necessary to use sar in the expression,
+	   according to the relation:
+
+		   (ih * X / ih) * sar = output_dar
+		   X = output_dar / sar
+
+	   Thus the previous example needs to be modified to:
+
+		   pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
+
+       o   Double the output size and put the input video in the bottom-right
+	   corner of the output padded area:
+
+		   pad="2*iw:2*ih:ow-iw:oh-ih"
+
+   palettegen
+       Generate one palette for a whole video stream.
+
+       It accepts the following options:
+
+       max_colors
+	   Set the maximum number of colors to quantize in the palette.  Note:
+	   the palette will still contain 256 colors; the unused palette
+	   entries will be black.
+
+       reserve_transparent
+	   Create a palette of 255 colors maximum and reserve the last one for
+	   transparency. Reserving the transparency color is useful for GIF
+	   optimization.  If not set, the maximum of colors in the palette
+	   will be 256. You probably want to disable this option for a
+	   standalone image.  Set by default.
+
+       transparency_color
+	   Set the color that will be used as background for transparency.
+
+       stats_mode
+	   Set statistics mode.
+
+	   It accepts the following values:
+
+	   full
+	       Compute full frame histograms.
+
+	   diff
+	       Compute histograms only for the part that differs from previous
+	       frame. This might be relevant to give more importance to the
+	       moving part of your input if the background is static.
+
+	   single
+	       Compute new histogram for each frame.
+
+	   Default value is full.
+
+       The filter also exports the frame metadata "lavfi.color_quant_ratio"
+       ("nb_color_in / nb_color_out") which you can use to evaluate the degree
+       of color quantization of the palette. This information is also visible
+       at info logging level.
+
+       Examples
+
+       o   Generate a representative palette of a given video using ffmpeg:
+
+		   ffmpeg -i input.mkv -vf palettegen palette.png
+
+   paletteuse
+       Use a palette to downsample an input video stream.
+
+       The filter takes two inputs: one video stream and a palette. The
+       palette must be a 256 pixels image.
+
+       It accepts the following options:
+
+       dither
+	   Select dithering mode. Available algorithms are:
+
+	   bayer
+	       Ordered 8x8 bayer dithering (deterministic)
+
+	   heckbert
+	       Dithering as defined by Paul Heckbert in 1982 (simple error
+	       diffusion).  Note: this dithering is sometimes considered
+	       "wrong" and is included as a reference.
+
+	   floyd_steinberg
+	       Floyd and Steingberg dithering (error diffusion)
+
+	   sierra2
+	       Frankie Sierra dithering v2 (error diffusion)
+
+	   sierra2_4a
+	       Frankie Sierra dithering v2 "Lite" (error diffusion)
+
+	   sierra3
+	       Frankie Sierra dithering v3 (error diffusion)
+
+	   burkes
+	       Burkes dithering (error diffusion)
+
+	   atkinson
+	       Atkinson dithering by Bill Atkinson at Apple Computer (error
+	       diffusion)
+
+	   Default is sierra2_4a.
+
+       bayer_scale
+	   When bayer dithering is selected, this option defines the scale of
+	   the pattern (how much the crosshatch pattern is visible). A low
+	   value means more visible pattern for less banding, and higher value
+	   means less visible pattern at the cost of more banding.
+
+	   The option must be an integer value in the range [0,5]. Default is
+	   2.
+
+       diff_mode
+	   If set, define the zone to process
+
+	   rectangle
+	       Only the changing rectangle will be reprocessed. This is
+	       similar to GIF cropping/offsetting compression mechanism. This
+	       option can be useful for speed if only a part of the image is
+	       changing, and has use cases such as limiting the scope of the
+	       error diffusal dither to the rectangle that bounds the moving
+	       scene (it leads to more deterministic output if the scene
+	       doesn't change much, and as a result less moving noise and
+	       better GIF compression).
+
+	   Default is none.
+
+       new Take new palette for each output frame.
+
+       alpha_threshold
+	   Sets the alpha threshold for transparency. Alpha values above this
+	   threshold will be treated as completely opaque, and values below
+	   this threshold will be treated as completely transparent.
+
+	   The option must be an integer value in the range [0,255]. Default
+	   is 128.
+
+       Examples
+
+       o   Use a palette (generated for example with palettegen) to encode a
+	   GIF using ffmpeg:
+
+		   ffmpeg -i input.mkv -i palette.png -lavfi paletteuse output.gif
+
+   perspective
+       Correct perspective of video not recorded perpendicular to the screen.
+
+       A description of the accepted parameters follows.
+
+       x0
+       y0
+       x1
+       y1
+       x2
+       y2
+       x3
+       y3  Set coordinates expression for top left, top right, bottom left and
+	   bottom right corners.  Default values are "0:0:W:0:0:H:W:H" with
+	   which perspective will remain unchanged.  If the "sense" option is
+	   set to "source", then the specified points will be sent to the
+	   corners of the destination. If the "sense" option is set to
+	   "destination", then the corners of the source will be sent to the
+	   specified coordinates.
+
+	   The expressions can use the following variables:
+
+	   W
+	   H   the width and height of video frame.
+
+	   in  Input frame count.
+
+	   on  Output frame count.
+
+       interpolation
+	   Set interpolation for perspective correction.
+
+	   It accepts the following values:
+
+	   linear
+	   cubic
+
+	   Default value is linear.
+
+       sense
+	   Set interpretation of coordinate options.
+
+	   It accepts the following values:
+
+	   0, source
+	       Send point in the source specified by the given coordinates to
+	       the corners of the destination.
+
+	   1, destination
+	       Send the corners of the source to the point in the destination
+	       specified by the given coordinates.
+
+	       Default value is source.
+
+       eval
+	   Set when the expressions for coordinates x0,y0,...x3,y3 are
+	   evaluated.
+
+	   It accepts the following values:
+
+	   init
+	       only evaluate expressions once during the filter initialization
+	       or when a command is processed
+
+	   frame
+	       evaluate expressions for each incoming frame
+
+	   Default value is init.
+
+   phase
+       Delay interlaced video by one field time so that the field order
+       changes.
+
+       The intended use is to fix PAL movies that have been captured with the
+       opposite field order to the film-to-video transfer.
+
+       A description of the accepted parameters follows.
+
+       mode
+	   Set phase mode.
+
+	   It accepts the following values:
+
+	   t   Capture field order top-first, transfer bottom-first.  Filter
+	       will delay the bottom field.
+
+	   b   Capture field order bottom-first, transfer top-first.  Filter
+	       will delay the top field.
+
+	   p   Capture and transfer with the same field order. This mode only
+	       exists for the documentation of the other options to refer to,
+	       but if you actually select it, the filter will faithfully do
+	       nothing.
+
+	   a   Capture field order determined automatically by field flags,
+	       transfer opposite.  Filter selects among t and b modes on a
+	       frame by frame basis using field flags. If no field information
+	       is available, then this works just like u.
+
+	   u   Capture unknown or varying, transfer opposite.  Filter selects
+	       among t and b on a frame by frame basis by analyzing the images
+	       and selecting the alternative that produces best match between
+	       the fields.
+
+	   T   Capture top-first, transfer unknown or varying.	Filter selects
+	       among t and p using image analysis.
+
+	   B   Capture bottom-first, transfer unknown or varying.  Filter
+	       selects among b and p using image analysis.
+
+	   A   Capture determined by field flags, transfer unknown or varying.
+	       Filter selects among t, b and p using field flags and image
+	       analysis. If no field information is available, then this works
+	       just like U. This is the default mode.
+
+	   U   Both capture and transfer unknown or varying.  Filter selects
+	       among t, b and p using image analysis only.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   photosensitivity
+       Reduce various flashes in video, so to help users with epilepsy.
+
+       It accepts the following options:
+
+       frames, f
+	   Set how many frames to use when filtering. Default is 30.
+
+       threshold, t
+	   Set detection threshold factor. Default is 1.  Lower is stricter.
+
+       skip
+	   Set how many pixels to skip when sampling frames. Default is 1.
+	   Allowed range is from 1 to 1024.
+
+       bypass
+	   Leave frames unchanged. Default is disabled.
+
+   pixdesctest
+       Pixel format descriptor test filter, mainly useful for internal
+       testing. The output video should be equal to the input video.
+
+       For example:
+
+	       format=monow, pixdesctest
+
+       can be used to test the monowhite pixel format descriptor definition.
+
+   pixelize
+       Apply pixelization to video stream.
+
+       The filter accepts the following options:
+
+       width, w
+       height, h
+	   Set block dimensions that will be used for pixelization.  Default
+	   value is 16.
+
+       mode, m
+	   Set the mode of pixelization used.
+
+	   Possible values are:
+
+	   avg
+	   min
+	   max
+
+	   Default value is "avg".
+
+       planes, p
+	   Set what planes to filter. Default is to filter all planes.
+
+       Commands
+
+       This filter supports all options as commands.
+
+   pixscope
+       Display sample values of color channels. Mainly useful for checking
+       color and levels. Minimum supported resolution is 640x480.
+
+       The filters accept the following options:
+
+       x   Set scope X position, relative offset on X axis.
+
+       y   Set scope Y position, relative offset on Y axis.
+
+       w   Set scope width.
+
+       h   Set scope height.
+
+       o   Set window opacity. This window also holds statistics about pixel
+	   area.
+
+       wx  Set window X position, relative offset on X axis.
+
+       wy  Set window Y position, relative offset on Y axis.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   pp
+       Enable the specified chain of postprocessing subfilters using
+       libpostproc. This library should be automatically selected with a GPL
+       build ("--enable-gpl").	Subfilters must be separated by '/' and can be
+       disabled by prepending a '-'.  Each subfilter and some options have a
+       short and a long name that can be used interchangeably, i.e. dr/dering
+       are the same.
+
+       The filters accept the following options:
+
+       subfilters
+	   Set postprocessing subfilters string.
+
+       All subfilters share common options to determine their scope:
+
+       a/autoq
+	   Honor the quality commands for this subfilter.
+
+       c/chrom
+	   Do chrominance filtering, too (default).
+
+       y/nochrom
+	   Do luminance filtering only (no chrominance).
+
+       n/noluma
+	   Do chrominance filtering only (no luminance).
+
+       These options can be appended after the subfilter name, separated by a
+       '|'.
+
+       Available subfilters are:
+
+       hb/hdeblock[|difference[|flatness]]
+	   Horizontal deblocking filter
+
+	   difference
+	       Difference factor where higher values mean more deblocking
+	       (default: 32).
+
+	   flatness
+	       Flatness threshold where lower values mean more deblocking
+	       (default: 39).
+
+       vb/vdeblock[|difference[|flatness]]
+	   Vertical deblocking filter
+
+	   difference
+	       Difference factor where higher values mean more deblocking
+	       (default: 32).
+
+	   flatness
+	       Flatness threshold where lower values mean more deblocking
+	       (default: 39).
+
+       ha/hadeblock[|difference[|flatness]]
+	   Accurate horizontal deblocking filter
+
+	   difference
+	       Difference factor where higher values mean more deblocking
+	       (default: 32).
+
+	   flatness
+	       Flatness threshold where lower values mean more deblocking
+	       (default: 39).
+
+       va/vadeblock[|difference[|flatness]]
+	   Accurate vertical deblocking filter
+
+	   difference
+	       Difference factor where higher values mean more deblocking
+	       (default: 32).
+
+	   flatness
+	       Flatness threshold where lower values mean more deblocking
+	       (default: 39).
+
+       The horizontal and vertical deblocking filters share the difference and
+       flatness values so you cannot set different horizontal and vertical
+       thresholds.
+
+       h1/x1hdeblock
+	   Experimental horizontal deblocking filter
+
+       v1/x1vdeblock
+	   Experimental vertical deblocking filter
+
+       dr/dering
+	   Deringing filter
+
+       tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise
+       reducer
+	   threshold1
+	       larger -> stronger filtering
+
+	   threshold2
+	       larger -> stronger filtering
+
+	   threshold3
+	       larger -> stronger filtering
+
+       al/autolevels[:f/fullyrange], automatic brightness / contrast
+       correction
+	   f/fullyrange
+	       Stretch luminance to "0-255".
+
+       lb/linblenddeint
+	   Linear blend deinterlacing filter that deinterlaces the given block
+	   by filtering all lines with a "(1 2 1)" filter.
+
+       li/linipoldeint
+	   Linear interpolating deinterlacing filter that deinterlaces the
+	   given block by linearly interpolating every second line.
+
+       ci/cubicipoldeint
+	   Cubic interpolating deinterlacing filter deinterlaces the given
+	   block by cubically interpolating every second line.
+
+       md/mediandeint
+	   Median deinterlacing filter that deinterlaces the given block by
+	   applying a median filter to every second line.
+
+       fd/ffmpegdeint
+	   FFmpeg deinterlacing filter that deinterlaces the given block by
+	   filtering every second line with a "(-1 4 2 4 -1)" filter.
+
+       l5/lowpass5
+	   Vertically applied FIR lowpass deinterlacing filter that
+	   deinterlaces the given block by filtering all lines with a "(-1 2 6
+	   2 -1)" filter.
+
+       fq/forceQuant[|quantizer]
+	   Overrides the quantizer table from the input with the constant
+	   quantizer you specify.
+
+	   quantizer
+	       Quantizer to use
+
+       de/default
+	   Default pp filter combination ("hb|a,vb|a,dr|a")
+
+       fa/fast
+	   Fast pp filter combination ("h1|a,v1|a,dr|a")
+
+       ac  High quality pp filter combination ("ha|a|128|7,va|a,dr|a")
+
+       Examples
+
+       o   Apply horizontal and vertical deblocking, deringing and automatic
+	   brightness/contrast:
+
+		   pp=hb/vb/dr/al
+
+       o   Apply default filters without brightness/contrast correction:
+
+		   pp=de/-al
+
+       o   Apply default filters and temporal denoiser:
+
+		   pp=default/tmpnoise|1|2|3
+
+       o   Apply deblocking on luminance only, and switch vertical deblocking
+	   on or off automatically depending on available CPU time:
+
+		   pp=hb|y/vb|a
+
+   pp7
+       Apply Postprocessing filter 7. It is variant of the spp filter, similar
+       to spp = 6 with 7 point DCT, where only the center sample is used after
+       IDCT.
+
+       The filter accepts the following options:
+
+       qp  Force a constant quantization parameter. It accepts an integer in
+	   range 0 to 63. If not set, the filter will use the QP from the
+	   video stream (if available).
+
+       mode
+	   Set thresholding mode. Available modes are:
+
+	   hard
+	       Set hard thresholding.
+
+	   soft
+	       Set soft thresholding (better de-ringing effect, but likely
+	       blurrier).
+
+	   medium
+	       Set medium thresholding (good results, default).
+
+   premultiply
+       Apply alpha premultiply effect to input video stream using first plane
+       of second stream as alpha.
+
+       Both streams must have same dimensions and same pixel format.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       inplace
+	   Do not require 2nd input for processing, instead use alpha plane
+	   from input stream.
+
+   prewitt
+       Apply prewitt operator to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.
+
+       delta
+	   Set value which will be added to filtered result.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   pseudocolor
+       Alter frame colors in video with pseudocolors.
+
+       This filter accepts the following options:
+
+       c0  set pixel first component expression
+
+       c1  set pixel second component expression
+
+       c2  set pixel third component expression
+
+       c3  set pixel fourth component expression, corresponds to the alpha
+	   component
+
+       index, i
+	   set component to use as base for altering colors
+
+       preset, p
+	   Pick one of built-in LUTs. By default is set to none.
+
+	   Available LUTs:
+
+	   magma
+	   inferno
+	   plasma
+	   viridis
+	   turbo
+	   cividis
+	   range1
+	   range2
+	   shadows
+	   highlights
+	   solar
+	   nominal
+	   preferred
+	   total
+	   spectral
+       opacity
+	   Set opacity of output colors. Allowed range is from 0 to 1.
+	   Default value is set to 1.
+
+       Each of the expression options specifies the expression to use for
+       computing the lookup table for the corresponding pixel component
+       values.
+
+       The expressions can contain the following constants and functions:
+
+       w
+       h   The input width and height.
+
+       val The input value for the pixel component.
+
+       ymin, umin, vmin, amin
+	   The minimum allowed component value.
+
+       ymax, umax, vmax, amax
+	   The maximum allowed component value.
+
+       All expressions default to "val".
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Change too high luma values to gradient:
+
+		   pseudocolor="'if(between(val,ymax,amax),lerp(ymin,ymax,(val-ymax)/(amax-ymax)),-1):if(between(val,ymax,amax),lerp(umax,umin,(val-ymax)/(amax-ymax)),-1):if(between(val,ymax,amax),lerp(vmin,vmax,(val-ymax)/(amax-ymax)),-1):-1'"
+
+   psnr
+       Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
+       Ratio) between two input videos.
+
+       This filter takes in input two input videos, the first input is
+       considered the "main" source and is passed unchanged to the output. The
+       second input is used as a "reference" video for computing the PSNR.
+
+       Both video inputs must have the same resolution and pixel format for
+       this filter to work correctly. Also it assumes that both inputs have
+       the same number of frames, which are compared one by one.
+
+       The obtained average PSNR is printed through the logging system.
+
+       The filter stores the accumulated MSE (mean squared error) of each
+       frame, and at the end of the processing it is averaged across all
+       frames equally, and the following formula is applied to obtain the
+       PSNR:
+
+	       PSNR = 10*log10(MAX^2/MSE)
+
+       Where MAX is the average of the maximum values of each component of the
+       image.
+
+       The description of the accepted parameters follows.
+
+       stats_file, f
+	   If specified the filter will use the named file to save the PSNR of
+	   each individual frame. When filename equals "-" the data is sent to
+	   standard output.
+
+       stats_version
+	   Specifies which version of the stats file format to use. Details of
+	   each format are written below.  Default value is 1.
+
+       stats_add_max
+	   Determines whether the max value is output to the stats log.
+	   Default value is 0.	Requires stats_version >= 2. If this is set
+	   and stats_version < 2, the filter will return an error.
+
+       This filter also supports the framesync options.
+
+       The file printed if stats_file is selected, contains a sequence of
+       key/value pairs of the form key:value for each compared couple of
+       frames.
+
+       If a stats_version greater than 1 is specified, a header line precedes
+       the list of per-frame-pair stats, with key value pairs following the
+       frame format with the following parameters:
+
+       psnr_log_version
+	   The version of the log file format. Will match stats_version.
+
+       fields
+	   A comma separated list of the per-frame-pair parameters included in
+	   the log.
+
+       A description of each shown per-frame-pair parameter follows:
+
+       n   sequential number of the input frame, starting from 1
+
+       mse_avg
+	   Mean Square Error pixel-by-pixel average difference of the compared
+	   frames, averaged over all the image components.
+
+       mse_y, mse_u, mse_v, mse_r, mse_g, mse_b, mse_a
+	   Mean Square Error pixel-by-pixel average difference of the compared
+	   frames for the component specified by the suffix.
+
+       psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a
+	   Peak Signal to Noise ratio of the compared frames for the component
+	   specified by the suffix.
+
+       max_avg, max_y, max_u, max_v
+	   Maximum allowed value for each channel, and average over all
+	   channels.
+
+       Examples
+
+       o   For example:
+
+		   movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
+		   [main][ref] psnr="stats_file=stats.log" [out]
+
+	   On this example the input file being processed is compared with the
+	   reference file ref_movie.mpg. The PSNR of each individual frame is
+	   stored in stats.log.
+
+       o   Another example with different containers:
+
+		   ffmpeg -i main.mpg -i ref.mkv -lavfi  "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]psnr" -f null -
+
+   pullup
+       Pulldown reversal (inverse telecine) filter, capable of handling mixed
+       hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps
+       progressive content.
+
+       The pullup filter is designed to take advantage of future context in
+       making its decisions. This filter is stateless in the sense that it
+       does not lock onto a pattern to follow, but it instead looks forward to
+       the following fields in order to identify matches and rebuild
+       progressive frames.
+
+       To produce content with an even framerate, insert the fps filter after
+       pullup, use "fps=24000/1001" if the input frame rate is 29.97fps,
+       "fps=24" for 30fps and the (rare) telecined 25fps input.
+
+       The filter accepts the following options:
+
+       jl
+       jr
+       jt
+       jb  These options set the amount of "junk" to ignore at the left,
+	   right, top, and bottom of the image, respectively. Left and right
+	   are in units of 8 pixels, while top and bottom are in units of 2
+	   lines.  The default is 8 pixels on each side.
+
+       sb  Set the strict breaks. Setting this option to 1 will reduce the
+	   chances of filter generating an occasional mismatched frame, but it
+	   may also cause an excessive number of frames to be dropped during
+	   high motion sequences.  Conversely, setting it to -1 will make
+	   filter match fields more easily.  This may help processing of video
+	   where there is slight blurring between the fields, but may also
+	   cause there to be interlaced frames in the output.  Default value
+	   is 0.
+
+       mp  Set the metric plane to use. It accepts the following values:
+
+	   l   Use luma plane.
+
+	   u   Use chroma blue plane.
+
+	   v   Use chroma red plane.
+
+	   This option may be set to use chroma plane instead of the default
+	   luma plane for doing filter's computations. This may improve
+	   accuracy on very clean source material, but more likely will
+	   decrease accuracy, especially if there is chroma noise (rainbow
+	   effect) or any grayscale video.  The main purpose of setting mp to
+	   a chroma plane is to reduce CPU load and make pullup usable in
+	   realtime on slow machines.
+
+       For best results (without duplicated frames in the output file) it is
+       necessary to change the output frame rate. For example, to inverse
+       telecine NTSC input:
+
+	       ffmpeg -i input -vf pullup -r 24000/1001 ...
+
+   qp
+       Change video quantization parameters (QP).
+
+       The filter accepts the following option:
+
+       qp  Set expression for quantization parameter.
+
+       The expression is evaluated through the eval API and can contain, among
+       others, the following constants:
+
+       known
+	   1 if index is not 129, 0 otherwise.
+
+       qp  Sequential index starting from -129 to 128.
+
+       Examples
+
+       o   Some equation like:
+
+		   qp=2+2*sin(PI*qp)
+
+   random
+       Flush video frames from internal cache of frames into a random order.
+       No frame is discarded.  Inspired by frei0r nervous filter.
+
+       frames
+	   Set size in number of frames of internal cache, in range from 2 to
+	   512. Default is 30.
+
+       seed
+	   Set seed for random number generator, must be an integer included
+	   between 0 and "UINT32_MAX". If not specified, or if explicitly set
+	   to less than 0, the filter will try to use a good random seed on a
+	   best effort basis.
+
+   readeia608
+       Read closed captioning (EIA-608) information from the top lines of a
+       video frame.
+
+       This filter adds frame metadata for "lavfi.readeia608.X.cc" and
+       "lavfi.readeia608.X.line", where "X" is the number of the identified
+       line with EIA-608 data (starting from 0). A description of each
+       metadata value follows:
+
+       lavfi.readeia608.X.cc
+	   The two bytes stored as EIA-608 data (printed in hexadecimal).
+
+       lavfi.readeia608.X.line
+	   The number of the line on which the EIA-608 data was identified and
+	   read.
+
+       This filter accepts the following options:
+
+       scan_min
+	   Set the line to start scanning for EIA-608 data. Default is 0.
+
+       scan_max
+	   Set the line to end scanning for EIA-608 data. Default is 29.
+
+       spw Set the ratio of width reserved for sync code detection.  Default
+	   is 0.27. Allowed range is "[0.1 - 0.7]".
+
+       chp Enable checking the parity bit. In the event of a parity error, the
+	   filter will output 0x00 for that character. Default is false.
+
+       lp  Lowpass lines prior to further processing. Default is enabled.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+       Examples
+
+       o   Output a csv with presentation time and the first two lines of
+	   identified EIA-608 captioning data.
+
+		   ffprobe -f lavfi -i movie=captioned_video.mov,readeia608 -show_entries frame=pts_time:frame_tags=lavfi.readeia608.0.cc,lavfi.readeia608.1.cc -of csv
+
+   readvitc
+       Read vertical interval timecode (VITC) information from the top lines
+       of a video frame.
+
+       The filter adds frame metadata key "lavfi.readvitc.tc_str" with the
+       timecode value, if a valid timecode has been detected. Further metadata
+       key "lavfi.readvitc.found" is set to 0/1 depending on whether timecode
+       data has been found or not.
+
+       This filter accepts the following options:
+
+       scan_max
+	   Set the maximum number of lines to scan for VITC data. If the value
+	   is set to "-1" the full video frame is scanned. Default is 45.
+
+       thr_b
+	   Set the luma threshold for black. Accepts float numbers in the
+	   range [0.0,1.0], default value is 0.2. The value must be equal or
+	   less than "thr_w".
+
+       thr_w
+	   Set the luma threshold for white. Accepts float numbers in the
+	   range [0.0,1.0], default value is 0.6. The value must be equal or
+	   greater than "thr_b".
+
+       Examples
+
+       o   Detect and draw VITC data onto the video frame; if no valid VITC is
+	   detected, draw "--:--:--:--" as a placeholder:
+
+		   ffmpeg -i input.avi -filter:v 'readvitc,drawtext=fontfile=FreeMono.ttf:text=%{metadata\\:lavfi.readvitc.tc_str\\:--\\\\\\:--\\\\\\:--\\\\\\:--}:x=(w-tw)/2:y=400-ascent'
+
+   remap
+       Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream.
+
+       Destination pixel at position (X, Y) will be picked from source (x, y)
+       position where x = Xmap(X, Y) and y = Ymap(X, Y). If mapping values are
+       out of range, zero value for pixel will be used for destination pixel.
+
+       Xmap and Ymap input video streams must be of same dimensions. Output
+       video stream will have Xmap/Ymap video stream dimensions.  Xmap and
+       Ymap input video streams are 16bit depth, single channel.
+
+       format
+	   Specify pixel format of output from this filter. Can be "color" or
+	   "gray".  Default is "color".
+
+       fill
+	   Specify the color of the unmapped pixels. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+	   Default color is "black".
+
+   removegrain
+       The removegrain filter is a spatial denoiser for progressive video.
+
+       m0  Set mode for the first plane.
+
+       m1  Set mode for the second plane.
+
+       m2  Set mode for the third plane.
+
+       m3  Set mode for the fourth plane.
+
+       Range of mode is from 0 to 24. Description of each mode follows:
+
+       0   Leave input plane unchanged. Default.
+
+       1   Clips the pixel with the minimum and maximum of the 8 neighbour
+	   pixels.
+
+       2   Clips the pixel with the second minimum and maximum of the 8
+	   neighbour pixels.
+
+       3   Clips the pixel with the third minimum and maximum of the 8
+	   neighbour pixels.
+
+       4   Clips the pixel with the fourth minimum and maximum of the 8
+	   neighbour pixels.  This is equivalent to a median filter.
+
+       5   Line-sensitive clipping giving the minimal change.
+
+       6   Line-sensitive clipping, intermediate.
+
+       7   Line-sensitive clipping, intermediate.
+
+       8   Line-sensitive clipping, intermediate.
+
+       9   Line-sensitive clipping on a line where the neighbours pixels are
+	   the closest.
+
+       10  Replaces the target pixel with the closest neighbour.
+
+       11  [1 2 1] horizontal and vertical kernel blur.
+
+       12  Same as mode 11.
+
+       13  Bob mode, interpolates top field from the line where the neighbours
+	   pixels are the closest.
+
+       14  Bob mode, interpolates bottom field from the line where the
+	   neighbours pixels are the closest.
+
+       15  Bob mode, interpolates top field. Same as 13 but with a more
+	   complicated interpolation formula.
+
+       16  Bob mode, interpolates bottom field. Same as 14 but with a more
+	   complicated interpolation formula.
+
+       17  Clips the pixel with the minimum and maximum of respectively the
+	   maximum and minimum of each pair of opposite neighbour pixels.
+
+       18  Line-sensitive clipping using opposite neighbours whose greatest
+	   distance from the current pixel is minimal.
+
+       19  Replaces the pixel with the average of its 8 neighbours.
+
+       20  Averages the 9 pixels ([1 1 1] horizontal and vertical blur).
+
+       21  Clips pixels using the averages of opposite neighbour.
+
+       22  Same as mode 21 but simpler and faster.
+
+       23  Small edge and halo removal, but reputed useless.
+
+       24  Similar as 23.
+
+   removelogo
+       Suppress a TV station logo, using an image file to determine which
+       pixels comprise the logo. It works by filling in the pixels that
+       comprise the logo with neighboring pixels.
+
+       The filter accepts the following options:
+
+       filename, f
+	   Set the filter bitmap file, which can be any image format supported
+	   by libavformat. The width and height of the image file must match
+	   those of the video stream being processed.
+
+       Pixels in the provided bitmap image with a value of zero are not
+       considered part of the logo, non-zero pixels are considered part of the
+       logo. If you use white (255) for the logo and black (0) for the rest,
+       you will be safe. For making the filter bitmap, it is recommended to
+       take a screen capture of a black frame with the logo visible, and then
+       using a threshold filter followed by the erode filter once or twice.
+
+       If needed, little splotches can be fixed manually. Remember that if
+       logo pixels are not covered, the filter quality will be much reduced.
+       Marking too many pixels as part of the logo does not hurt as much, but
+       it will increase the amount of blurring needed to cover over the image
+       and will destroy more information than necessary, and extra pixels will
+       slow things down on a large logo.
+
+   repeatfields
+       This filter uses the repeat_field flag from the Video ES headers and
+       hard repeats fields based on its value.
+
+   reverse
+       Reverse a video clip.
+
+       Warning: This filter requires memory to buffer the entire clip, so
+       trimming is suggested.
+
+       Examples
+
+       o   Take the first 5 seconds of a clip, and reverse it.
+
+		   trim=end=5,reverse
+
+   rgbashift
+       Shift R/G/B/A pixels horizontally and/or vertically.
+
+       The filter accepts the following options:
+
+       rh  Set amount to shift red horizontally.
+
+       rv  Set amount to shift red vertically.
+
+       gh  Set amount to shift green horizontally.
+
+       gv  Set amount to shift green vertically.
+
+       bh  Set amount to shift blue horizontally.
+
+       bv  Set amount to shift blue vertically.
+
+       ah  Set amount to shift alpha horizontally.
+
+       av  Set amount to shift alpha vertically.
+
+       edge
+	   Set edge mode, can be smear, default, or warp.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   roberts
+       Apply roberts cross operator to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.
+
+       delta
+	   Set value which will be added to filtered result.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   rotate
+       Rotate video by an arbitrary angle expressed in radians.
+
+       The filter accepts the following options:
+
+       A description of the optional parameters follows.
+
+       angle, a
+	   Set an expression for the angle by which to rotate the input video
+	   clockwise, expressed as a number of radians. A negative value will
+	   result in a counter-clockwise rotation. By default it is set to
+	   "0".
+
+	   This expression is evaluated for each frame.
+
+       out_w, ow
+	   Set the output width expression, default value is "iw".  This
+	   expression is evaluated just once during configuration.
+
+       out_h, oh
+	   Set the output height expression, default value is "ih".  This
+	   expression is evaluated just once during configuration.
+
+       bilinear
+	   Enable bilinear interpolation if set to 1, a value of 0 disables
+	   it. Default value is 1.
+
+       fillcolor, c
+	   Set the color used to fill the output area not covered by the
+	   rotated image. For the general syntax of this option, check the
+	   "Color" section in the ffmpeg-utils manual.	If the special value
+	   "none" is selected then no background is printed (useful for
+	   example if the background is never shown).
+
+	   Default value is "black".
+
+       The expressions for the angle and the output size can contain the
+       following constants and functions:
+
+       n   sequential number of the input frame, starting from 0. It is always
+	   NAN before the first frame is filtered.
+
+       t   time in seconds of the input frame, it is set to 0 when the filter
+	   is configured. It is always NAN before the first frame is filtered.
+
+       hsub
+       vsub
+	   horizontal and vertical chroma subsample values. For example for
+	   the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       in_w, iw
+       in_h, ih
+	   the input video width and height
+
+       out_w, ow
+       out_h, oh
+	   the output width and height, that is the size of the padded area as
+	   specified by the width and height expressions
+
+       rotw(a)
+       roth(a)
+	   the minimal width/height required for completely containing the
+	   input video rotated by a radians.
+
+	   These are only available when computing the out_w and out_h
+	   expressions.
+
+       Examples
+
+       o   Rotate the input by PI/6 radians clockwise:
+
+		   rotate=PI/6
+
+       o   Rotate the input by PI/6 radians counter-clockwise:
+
+		   rotate=-PI/6
+
+       o   Rotate the input by 45 degrees clockwise:
+
+		   rotate=45*PI/180
+
+       o   Apply a constant rotation with period T, starting from an angle of
+	   PI/3:
+
+		   rotate=PI/3+2*PI*t/T
+
+       o   Make the input video rotation oscillating with a period of T
+	   seconds and an amplitude of A radians:
+
+		   rotate=A*sin(2*PI/T*t)
+
+       o   Rotate the video, output size is chosen so that the whole rotating
+	   input video is always completely contained in the output:
+
+		   rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
+
+       o   Rotate the video, reduce the output size so that no background is
+	   ever shown:
+
+		   rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
+
+       Commands
+
+       The filter supports the following commands:
+
+       a, angle
+	   Set the angle expression.  The command accepts the same syntax of
+	   the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   sab
+       Apply Shape Adaptive Blur.
+
+       The filter accepts the following options:
+
+       luma_radius, lr
+	   Set luma blur filter strength, must be a value in range 0.1-4.0,
+	   default value is 1.0. A greater value will result in a more blurred
+	   image, and in slower processing.
+
+       luma_pre_filter_radius, lpfr
+	   Set luma pre-filter radius, must be a value in the 0.1-2.0 range,
+	   default value is 1.0.
+
+       luma_strength, ls
+	   Set luma maximum difference between pixels to still be considered,
+	   must be a value in the 0.1-100.0 range, default value is 1.0.
+
+       chroma_radius, cr
+	   Set chroma blur filter strength, must be a value in range -0.9-4.0.
+	   A greater value will result in a more blurred image, and in slower
+	   processing.
+
+       chroma_pre_filter_radius, cpfr
+	   Set chroma pre-filter radius, must be a value in the -0.9-2.0
+	   range.
+
+       chroma_strength, cs
+	   Set chroma maximum difference between pixels to still be
+	   considered, must be a value in the -0.9-100.0 range.
+
+       Each chroma option value, if not explicitly specified, is set to the
+       corresponding luma option value.
+
+   scale
+       Scale (resize) the input video, using the libswscale library.
+
+       The scale filter forces the output display aspect ratio to be the same
+       of the input, by changing the output sample aspect ratio.
+
+       If the input image format is different from the format requested by the
+       next filter, the scale filter will convert the input to the requested
+       format.
+
+       Options
+
+       The filter accepts the following options, or any of the options
+       supported by the libswscale scaler.
+
+       See the ffmpeg-scaler manual for the complete list of scaler options.
+
+       width, w
+       height, h
+	   Set the output video dimension expression. Default value is the
+	   input dimension.
+
+	   If the width or w value is 0, the input width is used for the
+	   output. If the height or h value is 0, the input height is used for
+	   the output.
+
+	   If one and only one of the values is -n with n >= 1, the scale
+	   filter will use a value that maintains the aspect ratio of the
+	   input image, calculated from the other specified dimension. After
+	   that it will, however, make sure that the calculated dimension is
+	   divisible by n and adjust the value if necessary.
+
+	   If both values are -n with n >= 1, the behavior will be identical
+	   to both values being set to 0 as previously detailed.
+
+	   See below for the list of accepted constants for use in the
+	   dimension expression.
+
+       eval
+	   Specify when to evaluate width and height expression. It accepts
+	   the following values:
+
+	   init
+	       Only evaluate expressions once during the filter initialization
+	       or when a command is processed.
+
+	   frame
+	       Evaluate expressions for each incoming frame.
+
+	   Default value is init.
+
+       interl
+	   Set the interlacing mode. It accepts the following values:
+
+	   1   Force interlaced aware scaling.
+
+	   0   Do not apply interlaced scaling.
+
+	   -1  Select interlaced aware scaling depending on whether the source
+	       frames are flagged as interlaced or not.
+
+	   Default value is 0.
+
+       flags
+	   Set libswscale scaling flags. See the ffmpeg-scaler manual for the
+	   complete list of values. If not explicitly specified the filter
+	   applies the default flags.
+
+       param0, param1
+	   Set libswscale input parameters for scaling algorithms that need
+	   them. See the ffmpeg-scaler manual for the complete documentation.
+	   If not explicitly specified the filter applies empty parameters.
+
+       size, s
+	   Set the video size. For the syntax of this option, check the "Video
+	   size" section in the ffmpeg-utils manual.
+
+       in_color_matrix
+       out_color_matrix
+	   Set in/output YCbCr color space type.
+
+	   This allows the autodetected value to be overridden as well as
+	   allows forcing a specific value used for the output and encoder.
+
+	   If not specified, the color space type depends on the pixel format.
+
+	   Possible values:
+
+	   auto
+	       Choose automatically.
+
+	   bt709
+	       Format conforming to International Telecommunication Union
+	       (ITU) Recommendation BT.709.
+
+	   fcc Set color space conforming to the United States Federal
+	       Communications Commission (FCC) Code of Federal Regulations
+	       (CFR) Title 47 (2003) 73.682 (a).
+
+	   bt601
+	   bt470
+	   smpte170m
+	       Set color space conforming to:
+
+	       o   ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
+
+	       o   ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
+
+	       o   Society of Motion Picture and Television Engineers (SMPTE)
+		   ST 170:2004
+
+	   smpte240m
+	       Set color space conforming to SMPTE ST 240:1999.
+
+	   bt2020
+	       Set color space conforming to ITU-R BT.2020 non-constant
+	       luminance system.
+
+       in_range
+       out_range
+	   Set in/output YCbCr sample range.
+
+	   This allows the autodetected value to be overridden as well as
+	   allows forcing a specific value used for the output and encoder. If
+	   not specified, the range depends on the pixel format. Possible
+	   values:
+
+	   auto/unknown
+	       Choose automatically.
+
+	   jpeg/full/pc
+	       Set full range (0-255 in case of 8-bit luma).
+
+	   mpeg/limited/tv
+	       Set "MPEG" range (16-235 in case of 8-bit luma).
+
+       force_original_aspect_ratio
+	   Enable decreasing or increasing output video width or height if
+	   necessary to keep the original aspect ratio. Possible values:
+
+	   disable
+	       Scale the video as specified and disable this feature.
+
+	   decrease
+	       The output video dimensions will automatically be decreased if
+	       needed.
+
+	   increase
+	       The output video dimensions will automatically be increased if
+	       needed.
+
+	   One useful instance of this option is that when you know a specific
+	   device's maximum allowed resolution, you can use this to limit the
+	   output video to that, while retaining the aspect ratio. For
+	   example, device A allows 1280x720 playback, and your video is
+	   1920x800. Using this option (set it to decrease) and specifying
+	   1280x720 to the command line makes the output 1280x533.
+
+	   Please note that this is a different thing than specifying -1 for w
+	   or h, you still need to specify the output resolution for this
+	   option to work.
+
+       force_divisible_by
+	   Ensures that both the output dimensions, width and height, are
+	   divisible by the given integer when used together with
+	   force_original_aspect_ratio. This works similar to using "-n" in
+	   the w and h options.
+
+	   This option respects the value set for force_original_aspect_ratio,
+	   increasing or decreasing the resolution accordingly. The video's
+	   aspect ratio may be slightly modified.
+
+	   This option can be handy if you need to have a video fit within or
+	   exceed a defined resolution using force_original_aspect_ratio but
+	   also have encoder restrictions on width or height divisibility.
+
+       The values of the w and h options are expressions containing the
+       following constants:
+
+       in_w
+       in_h
+	   The input width and height
+
+       iw
+       ih  These are the same as in_w and in_h.
+
+       out_w
+       out_h
+	   The output (scaled) width and height
+
+       ow
+       oh  These are the same as out_w and out_h
+
+       a   The same as iw / ih
+
+       sar input sample aspect ratio
+
+       dar The input display aspect ratio. Calculated from "(iw / ih) * sar".
+
+       hsub
+       vsub
+	   horizontal and vertical input chroma subsample values. For example
+	   for the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       ohsub
+       ovsub
+	   horizontal and vertical output chroma subsample values. For example
+	   for the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       n   The (sequential) number of the input frame, starting from 0.  Only
+	   available with "eval=frame".
+
+       t   The presentation timestamp of the input frame, expressed as a
+	   number of seconds. Only available with "eval=frame".
+
+       pos The position (byte offset) of the frame in the input stream, or NaN
+	   if this information is unavailable and/or meaningless (for example
+	   in case of synthetic video).  Only available with "eval=frame".
+
+       Examples
+
+       o   Scale the input video to a size of 200x100
+
+		   scale=w=200:h=100
+
+	   This is equivalent to:
+
+		   scale=200:100
+
+	   or:
+
+		   scale=200x100
+
+       o   Specify a size abbreviation for the output size:
+
+		   scale=qcif
+
+	   which can also be written as:
+
+		   scale=size=qcif
+
+       o   Scale the input to 2x:
+
+		   scale=w=2*iw:h=2*ih
+
+       o   The above is the same as:
+
+		   scale=2*in_w:2*in_h
+
+       o   Scale the input to 2x with forced interlaced scaling:
+
+		   scale=2*iw:2*ih:interl=1
+
+       o   Scale the input to half size:
+
+		   scale=w=iw/2:h=ih/2
+
+       o   Increase the width, and set the height to the same size:
+
+		   scale=3/2*iw:ow
+
+       o   Seek Greek harmony:
+
+		   scale=iw:1/PHI*iw
+		   scale=ih*PHI:ih
+
+       o   Increase the height, and set the width to 3/2 of the height:
+
+		   scale=w=3/2*oh:h=3/5*ih
+
+       o   Increase the size, making the size a multiple of the chroma
+	   subsample values:
+
+		   scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
+
+       o   Increase the width to a maximum of 500 pixels, keeping the same
+	   aspect ratio as the input:
+
+		   scale=w='min(500\, iw*3/2):h=-1'
+
+       o   Make pixels square by combining scale and setsar:
+
+		   scale='trunc(ih*dar):ih',setsar=1/1
+
+       o   Make pixels square by combining scale and setsar, making sure the
+	   resulting resolution is even (required by some codecs):
+
+		   scale='trunc(ih*dar/2)*2:trunc(ih/2)*2',setsar=1/1
+
+       Commands
+
+       This filter supports the following commands:
+
+       width, w
+       height, h
+	   Set the output video dimension expression.  The command accepts the
+	   same syntax of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   scale_cuda
+       Scale (resize) and convert (pixel format) the input video, using
+       accelerated CUDA kernels.  Setting the output width and height works in
+       the same way as for the scale filter.
+
+       The filter accepts the following options:
+
+       w
+       h   Set the output video dimension expression. Default value is the
+	   input dimension.
+
+	   Allows for the same expressions as the scale filter.
+
+       interp_algo
+	   Sets the algorithm used for scaling:
+
+	   nearest
+	       Nearest neighbour
+
+	       Used by default if input parameters match the desired output.
+
+	   bilinear
+	       Bilinear
+
+	   bicubic
+	       Bicubic
+
+	       This is the default.
+
+	   lanczos
+	       Lanczos
+
+       format
+	   Controls the output pixel format. By default, or if none is
+	   specified, the input pixel format is used.
+
+	   The filter does not support converting between YUV and RGB pixel
+	   formats.
+
+       passthrough
+	   If set to 0, every frame is processed, even if no conversion is
+	   neccesary.  This mode can be useful to use the filter as a buffer
+	   for a downstream frame-consumer that exhausts the limited decoder
+	   frame pool.
+
+	   If set to 1, frames are passed through as-is if they match the
+	   desired output parameters. This is the default behaviour.
+
+       param
+	   Algorithm-Specific parameter.
+
+	   Affects the curves of the bicubic algorithm.
+
+       force_original_aspect_ratio
+       force_divisible_by
+	   Work the same as the identical scale filter options.
+
+       Examples
+
+       o   Scale input to 720p, keeping aspect ratio and ensuring the output
+	   is yuv420p.
+
+		   scale_cuda=-2:720:format=yuv420p
+
+       o   Upscale to 4K using nearest neighbour algorithm.
+
+		   scale_cuda=4096:2160:interp_algo=nearest
+
+       o   Don't do any conversion or scaling, but copy all input frames into
+	   newly allocated ones.  This can be useful to deal with a filter and
+	   encode chain that otherwise exhausts the decoders frame pool.
+
+		   scale_cuda=passthrough=0
+
+   scale_npp
+       Use the NVIDIA Performance Primitives (libnpp) to perform scaling
+       and/or pixel format conversion on CUDA video frames. Setting the output
+       width and height works in the same way as for the scale filter.
+
+       The following additional options are accepted:
+
+       format
+	   The pixel format of the output CUDA frames. If set to the string
+	   "same" (the default), the input format will be kept. Note that
+	   automatic format negotiation and conversion is not yet supported
+	   for hardware frames
+
+       interp_algo
+	   The interpolation algorithm used for resizing. One of the
+	   following:
+
+	   nn  Nearest neighbour.
+
+	   linear
+	   cubic
+	   cubic2p_bspline
+	       2-parameter cubic (B=1, C=0)
+
+	   cubic2p_catmullrom
+	       2-parameter cubic (B=0, C=1/2)
+
+	   cubic2p_b05c03
+	       2-parameter cubic (B=1/2, C=3/10)
+
+	   super
+	       Supersampling
+
+	   lanczos
+       force_original_aspect_ratio
+	   Enable decreasing or increasing output video width or height if
+	   necessary to keep the original aspect ratio. Possible values:
+
+	   disable
+	       Scale the video as specified and disable this feature.
+
+	   decrease
+	       The output video dimensions will automatically be decreased if
+	       needed.
+
+	   increase
+	       The output video dimensions will automatically be increased if
+	       needed.
+
+	   One useful instance of this option is that when you know a specific
+	   device's maximum allowed resolution, you can use this to limit the
+	   output video to that, while retaining the aspect ratio. For
+	   example, device A allows 1280x720 playback, and your video is
+	   1920x800. Using this option (set it to decrease) and specifying
+	   1280x720 to the command line makes the output 1280x533.
+
+	   Please note that this is a different thing than specifying -1 for w
+	   or h, you still need to specify the output resolution for this
+	   option to work.
+
+       force_divisible_by
+	   Ensures that both the output dimensions, width and height, are
+	   divisible by the given integer when used together with
+	   force_original_aspect_ratio. This works similar to using "-n" in
+	   the w and h options.
+
+	   This option respects the value set for force_original_aspect_ratio,
+	   increasing or decreasing the resolution accordingly. The video's
+	   aspect ratio may be slightly modified.
+
+	   This option can be handy if you need to have a video fit within or
+	   exceed a defined resolution using force_original_aspect_ratio but
+	   also have encoder restrictions on width or height divisibility.
+
+       eval
+	   Specify when to evaluate width and height expression. It accepts
+	   the following values:
+
+	   init
+	       Only evaluate expressions once during the filter initialization
+	       or when a command is processed.
+
+	   frame
+	       Evaluate expressions for each incoming frame.
+
+       The values of the w and h options are expressions containing the
+       following constants:
+
+       in_w
+       in_h
+	   The input width and height
+
+       iw
+       ih  These are the same as in_w and in_h.
+
+       out_w
+       out_h
+	   The output (scaled) width and height
+
+       ow
+       oh  These are the same as out_w and out_h
+
+       a   The same as iw / ih
+
+       sar input sample aspect ratio
+
+       dar The input display aspect ratio. Calculated from "(iw / ih) * sar".
+
+       n   The (sequential) number of the input frame, starting from 0.  Only
+	   available with "eval=frame".
+
+       t   The presentation timestamp of the input frame, expressed as a
+	   number of seconds. Only available with "eval=frame".
+
+       pos The position (byte offset) of the frame in the input stream, or NaN
+	   if this information is unavailable and/or meaningless (for example
+	   in case of synthetic video).  Only available with "eval=frame".
+
+   scale2ref
+       Scale (resize) the input video, based on a reference video.
+
+       See the scale filter for available options, scale2ref supports the same
+       but uses the reference video instead of the main input as basis.
+       scale2ref also supports the following additional constants for the w
+       and h options:
+
+       main_w
+       main_h
+	   The main input video's width and height
+
+       main_a
+	   The same as main_w / main_h
+
+       main_sar
+	   The main input video's sample aspect ratio
+
+       main_dar, mdar
+	   The main input video's display aspect ratio. Calculated from
+	   "(main_w / main_h) * main_sar".
+
+       main_hsub
+       main_vsub
+	   The main input video's horizontal and vertical chroma subsample
+	   values.  For example for the pixel format "yuv422p" hsub is 2 and
+	   vsub is 1.
+
+       main_n
+	   The (sequential) number of the main input frame, starting from 0.
+	   Only available with "eval=frame".
+
+       main_t
+	   The presentation timestamp of the main input frame, expressed as a
+	   number of seconds. Only available with "eval=frame".
+
+       main_pos
+	   The position (byte offset) of the frame in the main input stream,
+	   or NaN if this information is unavailable and/or meaningless (for
+	   example in case of synthetic video).  Only available with
+	   "eval=frame".
+
+       Examples
+
+       o   Scale a subtitle stream (b) to match the main video (a) in size
+	   before overlaying
+
+		   'scale2ref[b][a];[a][b]overlay'
+
+       o   Scale a logo to 1/10th the height of a video, while preserving its
+	   display aspect ratio.
+
+		   [logo-in][video-in]scale2ref=w=oh*mdar:h=ih/10[logo-out][video-out]
+
+       Commands
+
+       This filter supports the following commands:
+
+       width, w
+       height, h
+	   Set the output video dimension expression.  The command accepts the
+	   same syntax of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+   scale2ref_npp
+       Use the NVIDIA Performance Primitives (libnpp) to scale (resize) the
+       input video, based on a reference video.
+
+       See the scale_npp filter for available options, scale2ref_npp supports
+       the same but uses the reference video instead of the main input as
+       basis. scale2ref_npp also supports the following additional constants
+       for the w and h options:
+
+       main_w
+       main_h
+	   The main input video's width and height
+
+       main_a
+	   The same as main_w / main_h
+
+       main_sar
+	   The main input video's sample aspect ratio
+
+       main_dar, mdar
+	   The main input video's display aspect ratio. Calculated from
+	   "(main_w / main_h) * main_sar".
+
+       main_n
+	   The (sequential) number of the main input frame, starting from 0.
+	   Only available with "eval=frame".
+
+       main_t
+	   The presentation timestamp of the main input frame, expressed as a
+	   number of seconds. Only available with "eval=frame".
+
+       main_pos
+	   The position (byte offset) of the frame in the main input stream,
+	   or NaN if this information is unavailable and/or meaningless (for
+	   example in case of synthetic video).  Only available with
+	   "eval=frame".
+
+       Examples
+
+       o   Scale a subtitle stream (b) to match the main video (a) in size
+	   before overlaying
+
+		   'scale2ref_npp[b][a];[a][b]overlay_cuda'
+
+       o   Scale a logo to 1/10th the height of a video, while preserving its
+	   display aspect ratio.
+
+		   [logo-in][video-in]scale2ref_npp=w=oh*mdar:h=ih/10[logo-out][video-out]
+
+   scharr
+       Apply scharr operator to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.
+
+       delta
+	   Set value which will be added to filtered result.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   scroll
+       Scroll input video horizontally and/or vertically by constant speed.
+
+       The filter accepts the following options:
+
+       horizontal, h
+	   Set the horizontal scrolling speed. Default is 0. Allowed range is
+	   from -1 to 1.  Negative values changes scrolling direction.
+
+       vertical, v
+	   Set the vertical scrolling speed. Default is 0. Allowed range is
+	   from -1 to 1.  Negative values changes scrolling direction.
+
+       hpos
+	   Set the initial horizontal scrolling position. Default is 0.
+	   Allowed range is from 0 to 1.
+
+       vpos
+	   Set the initial vertical scrolling position. Default is 0. Allowed
+	   range is from 0 to 1.
+
+       Commands
+
+       This filter supports the following commands:
+
+       horizontal, h
+	   Set the horizontal scrolling speed.
+
+       vertical, v
+	   Set the vertical scrolling speed.
+
+   scdet
+       Detect video scene change.
+
+       This filter sets frame metadata with mafd between frame, the scene
+       score, and forward the frame to the next filter, so they can use these
+       metadata to detect scene change or others.
+
+       In addition, this filter logs a message and sets frame metadata when it
+       detects a scene change by threshold.
+
+       "lavfi.scd.mafd" metadata keys are set with mafd for every frame.
+
+       "lavfi.scd.score" metadata keys are set with scene change score for
+       every frame to detect scene change.
+
+       "lavfi.scd.time" metadata keys are set with current filtered frame time
+       which detect scene change with threshold.
+
+       The filter accepts the following options:
+
+       threshold, t
+	   Set the scene change detection threshold as a percentage of maximum
+	   change. Good values are in the "[8.0, 14.0]" range. The range for
+	   threshold is "[0., 100.]".
+
+	   Default value is 10..
+
+       sc_pass, s
+	   Set the flag to pass scene change frames to the next filter.
+	   Default value is 0 You can enable it if you want to get snapshot of
+	   scene change frames only.
+
+   selectivecolor
+       Adjust cyan, magenta, yellow and black (CMYK) to certain ranges of
+       colors (such as "reds", "yellows", "greens", "cyans", ...). The
+       adjustment range is defined by the "purity" of the color (that is, how
+       saturated it already is).
+
+       This filter is similar to the Adobe Photoshop Selective Color tool.
+
+       The filter accepts the following options:
+
+       correction_method
+	   Select color correction method.
+
+	   Available values are:
+
+	   absolute
+	       Specified adjustments are applied "as-is" (added/subtracted to
+	       original pixel component value).
+
+	   relative
+	       Specified adjustments are relative to the original component
+	       value.
+
+	   Default is "absolute".
+
+       reds
+	   Adjustments for red pixels (pixels where the red component is the
+	   maximum)
+
+       yellows
+	   Adjustments for yellow pixels (pixels where the blue component is
+	   the minimum)
+
+       greens
+	   Adjustments for green pixels (pixels where the green component is
+	   the maximum)
+
+       cyans
+	   Adjustments for cyan pixels (pixels where the red component is the
+	   minimum)
+
+       blues
+	   Adjustments for blue pixels (pixels where the blue component is the
+	   maximum)
+
+       magentas
+	   Adjustments for magenta pixels (pixels where the green component is
+	   the minimum)
+
+       whites
+	   Adjustments for white pixels (pixels where all components are
+	   greater than 128)
+
+       neutrals
+	   Adjustments for all pixels except pure black and pure white
+
+       blacks
+	   Adjustments for black pixels (pixels where all components are
+	   lesser than 128)
+
+       psfile
+	   Specify a Photoshop selective color file (".asv") to import the
+	   settings from.
+
+       All the adjustment settings (reds, yellows, ...) accept up to 4 space
+       separated floating point adjustment values in the [-1,1] range,
+       respectively to adjust the amount of cyan, magenta, yellow and black
+       for the pixels of its range.
+
+       Examples
+
+       o   Increase cyan by 50% and reduce yellow by 33% in every green areas,
+	   and increase magenta by 27% in blue areas:
+
+		   selectivecolor=greens=.5 0 -.33 0:blues=0 .27
+
+       o   Use a Photoshop selective color preset:
+
+		   selectivecolor=psfile=MySelectiveColorPresets/Misty.asv
+
+   separatefields
+       The "separatefields" takes a frame-based video input and splits each
+       frame into its components fields, producing a new half height clip with
+       twice the frame rate and twice the frame count.
+
+       This filter use field-dominance information in frame to decide which of
+       each pair of fields to place first in the output.  If it gets it wrong
+       use setfield filter before "separatefields" filter.
+
+   setdar, setsar
+       The "setdar" filter sets the Display Aspect Ratio for the filter output
+       video.
+
+       This is done by changing the specified Sample (aka Pixel) Aspect Ratio,
+       according to the following equation:
+
+	       <DAR> = <HORIZONTAL_RESOLUTION> / <VERTICAL_RESOLUTION> * <SAR>
+
+       Keep in mind that the "setdar" filter does not modify the pixel
+       dimensions of the video frame. Also, the display aspect ratio set by
+       this filter may be changed by later filters in the filterchain, e.g. in
+       case of scaling or if another "setdar" or a "setsar" filter is applied.
+
+       The "setsar" filter sets the Sample (aka Pixel) Aspect Ratio for the
+       filter output video.
+
+       Note that as a consequence of the application of this filter, the
+       output display aspect ratio will change according to the equation
+       above.
+
+       Keep in mind that the sample aspect ratio set by the "setsar" filter
+       may be changed by later filters in the filterchain, e.g. if another
+       "setsar" or a "setdar" filter is applied.
+
+       It accepts the following parameters:
+
+       r, ratio, dar ("setdar" only), sar ("setsar" only)
+	   Set the aspect ratio used by the filter.
+
+	   The parameter can be a floating point number string, an expression,
+	   or a string of the form num:den, where num and den are the
+	   numerator and denominator of the aspect ratio. If the parameter is
+	   not specified, it is assumed the value "0".	In case the form
+	   "num:den" is used, the ":" character should be escaped.
+
+       max Set the maximum integer value to use for expressing numerator and
+	   denominator when reducing the expressed aspect ratio to a rational.
+	   Default value is 100.
+
+       The parameter sar is an expression containing the following constants:
+
+       E, PI, PHI
+	   These are approximated values for the mathematical constants e
+	   (Euler's number), pi (Greek pi), and phi (the golden ratio).
+
+       w, h
+	   The input width and height.
+
+       a   These are the same as w / h.
+
+       sar The input sample aspect ratio.
+
+       dar The input display aspect ratio. It is the same as (w / h) * sar.
+
+       hsub, vsub
+	   Horizontal and vertical chroma subsample values. For example, for
+	   the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       Examples
+
+       o   To change the display aspect ratio to 16:9, specify one of the
+	   following:
+
+		   setdar=dar=1.77777
+		   setdar=dar=16/9
+
+       o   To change the sample aspect ratio to 10:11, specify:
+
+		   setsar=sar=10/11
+
+       o   To set a display aspect ratio of 16:9, and specify a maximum
+	   integer value of 1000 in the aspect ratio reduction, use the
+	   command:
+
+		   setdar=ratio=16/9:max=1000
+
+   setfield
+       Force field for the output video frame.
+
+       The "setfield" filter marks the interlace type field for the output
+       frames. It does not change the input frame, but only sets the
+       corresponding property, which affects how the frame is treated by
+       following filters (e.g. "fieldorder" or "yadif").
+
+       The filter accepts the following options:
+
+       mode
+	   Available values are:
+
+	   auto
+	       Keep the same field property.
+
+	   bff Mark the frame as bottom-field-first.
+
+	   tff Mark the frame as top-field-first.
+
+	   prog
+	       Mark the frame as progressive.
+
+   setparams
+       Force frame parameter for the output video frame.
+
+       The "setparams" filter marks interlace and color range for the output
+       frames. It does not change the input frame, but only sets the
+       corresponding property, which affects how the frame is treated by
+       filters/encoders.
+
+       field_mode
+	   Available values are:
+
+	   auto
+	       Keep the same field property (default).
+
+	   bff Mark the frame as bottom-field-first.
+
+	   tff Mark the frame as top-field-first.
+
+	   prog
+	       Mark the frame as progressive.
+
+       range
+	   Available values are:
+
+	   auto
+	       Keep the same color range property (default).
+
+	   unspecified, unknown
+	       Mark the frame as unspecified color range.
+
+	   limited, tv, mpeg
+	       Mark the frame as limited range.
+
+	   full, pc, jpeg
+	       Mark the frame as full range.
+
+       color_primaries
+	   Set the color primaries.  Available values are:
+
+	   auto
+	       Keep the same color primaries property (default).
+
+	   bt709
+	   unknown
+	   bt470m
+	   bt470bg
+	   smpte170m
+	   smpte240m
+	   film
+	   bt2020
+	   smpte428
+	   smpte431
+	   smpte432
+	   jedec-p22
+       color_trc
+	   Set the color transfer.  Available values are:
+
+	   auto
+	       Keep the same color trc property (default).
+
+	   bt709
+	   unknown
+	   bt470m
+	   bt470bg
+	   smpte170m
+	   smpte240m
+	   linear
+	   log100
+	   log316
+	   iec61966-2-4
+	   bt1361e
+	   iec61966-2-1
+	   bt2020-10
+	   bt2020-12
+	   smpte2084
+	   smpte428
+	   arib-std-b67
+       colorspace
+	   Set the colorspace.	Available values are:
+
+	   auto
+	       Keep the same colorspace property (default).
+
+	   gbr
+	   bt709
+	   unknown
+	   fcc
+	   bt470bg
+	   smpte170m
+	   smpte240m
+	   ycgco
+	   bt2020nc
+	   bt2020c
+	   smpte2085
+	   chroma-derived-nc
+	   chroma-derived-c
+	   ictcp
+
+   sharpen_npp
+       Use the NVIDIA Performance Primitives (libnpp) to perform image
+       sharpening with border control.
+
+       The following additional options are accepted:
+
+       border_type
+	   Type of sampling to be used ad frame borders. One of the following:
+
+	   replicate
+	       Replicate pixel values.
+
+   shear
+       Apply shear transform to input video.
+
+       This filter supports the following options:
+
+       shx Shear factor in X-direction. Default value is 0.  Allowed range is
+	   from -2 to 2.
+
+       shy Shear factor in Y-direction. Default value is 0.  Allowed range is
+	   from -2 to 2.
+
+       fillcolor, c
+	   Set the color used to fill the output area not covered by the
+	   transformed video. For the general syntax of this option, check the
+	   "Color" section in the ffmpeg-utils manual.	If the special value
+	   "none" is selected then no background is printed (useful for
+	   example if the background is never shown).
+
+	   Default value is "black".
+
+       interp
+	   Set interpolation type. Can be "bilinear" or "nearest". Default is
+	   "bilinear".
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   showinfo
+       Show a line containing various information for each input video frame.
+       The input video is not modified.
+
+       This filter supports the following options:
+
+       checksum
+	   Calculate checksums of each plane. By default enabled.
+
+       The shown line contains a sequence of key/value pairs of the form
+       key:value.
+
+       The following values are shown in the output:
+
+       n   The (sequential) number of the input frame, starting from 0.
+
+       pts The Presentation TimeStamp of the input frame, expressed as a
+	   number of time base units. The time base unit depends on the filter
+	   input pad.
+
+       pts_time
+	   The Presentation TimeStamp of the input frame, expressed as a
+	   number of seconds.
+
+       pos The position of the frame in the input stream, or -1 if this
+	   information is unavailable and/or meaningless (for example in case
+	   of synthetic video).
+
+       fmt The pixel format name.
+
+       sar The sample aspect ratio of the input frame, expressed in the form
+	   num/den.
+
+       s   The size of the input frame. For the syntax of this option, check
+	   the "Video size" section in the ffmpeg-utils manual.
+
+       i   The type of interlaced mode ("P" for "progressive", "T" for top
+	   field first, "B" for bottom field first).
+
+       iskey
+	   This is 1 if the frame is a key frame, 0 otherwise.
+
+       type
+	   The picture type of the input frame ("I" for an I-frame, "P" for a
+	   P-frame, "B" for a B-frame, or "?" for an unknown type).  Also
+	   refer to the documentation of the "AVPictureType" enum and of the
+	   "av_get_picture_type_char" function defined in libavutil/avutil.h.
+
+       checksum
+	   The Adler-32 checksum (printed in hexadecimal) of all the planes of
+	   the input frame.
+
+       plane_checksum
+	   The Adler-32 checksum (printed in hexadecimal) of each plane of the
+	   input frame, expressed in the form "[c0 c1 c2 c3]".
+
+       mean
+	   The mean value of pixels in each plane of the input frame,
+	   expressed in the form "[mean0 mean1 mean2 mean3]".
+
+       stdev
+	   The standard deviation of pixel values in each plane of the input
+	   frame, expressed in the form "[stdev0 stdev1 stdev2 stdev3]".
+
+   showpalette
+       Displays the 256 colors palette of each frame. This filter is only
+       relevant for pal8 pixel format frames.
+
+       It accepts the following option:
+
+       s   Set the size of the box used to represent one palette color entry.
+	   Default is 30 (for a "30x30" pixel box).
+
+   shuffleframes
+       Reorder and/or duplicate and/or drop video frames.
+
+       It accepts the following parameters:
+
+       mapping
+	   Set the destination indexes of input frames.  This is space or '|'
+	   separated list of indexes that maps input frames to output frames.
+	   Number of indexes also sets maximal value that each index may have.
+	   '-1' index have special meaning and that is to drop frame.
+
+       The first frame has the index 0. The default is to keep the input
+       unchanged.
+
+       Examples
+
+       o   Swap second and third frame of every three frames of the input:
+
+		   ffmpeg -i INPUT -vf "shuffleframes=0 2 1" OUTPUT
+
+       o   Swap 10th and 1st frame of every ten frames of the input:
+
+		   ffmpeg -i INPUT -vf "shuffleframes=9 1 2 3 4 5 6 7 8 0" OUTPUT
+
+   shufflepixels
+       Reorder pixels in video frames.
+
+       This filter accepts the following options:
+
+       direction, d
+	   Set shuffle direction. Can be forward or inverse direction.
+	   Default direction is forward.
+
+       mode, m
+	   Set shuffle mode. Can be horizontal, vertical or block mode.
+
+       width, w
+       height, h
+	   Set shuffle block_size. In case of horizontal shuffle mode only
+	   width part of size is used, and in case of vertical shuffle mode
+	   only height part of size is used.
+
+       seed, s
+	   Set random seed used with shuffling pixels. Mainly useful to set to
+	   be able to reverse filtering process to get original input.	For
+	   example, to reverse forward shuffle you need to use same parameters
+	   and exact same seed and to set direction to inverse.
+
+   shuffleplanes
+       Reorder and/or duplicate video planes.
+
+       It accepts the following parameters:
+
+       map0
+	   The index of the input plane to be used as the first output plane.
+
+       map1
+	   The index of the input plane to be used as the second output plane.
+
+       map2
+	   The index of the input plane to be used as the third output plane.
+
+       map3
+	   The index of the input plane to be used as the fourth output plane.
+
+       The first plane has the index 0. The default is to keep the input
+       unchanged.
+
+       Examples
+
+       o   Swap the second and third planes of the input:
+
+		   ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
+
+   signalstats
+       Evaluate various visual metrics that assist in determining issues
+       associated with the digitization of analog video media.
+
+       By default the filter will log these metadata values:
+
+       YMIN
+	   Display the minimal Y value contained within the input frame.
+	   Expressed in range of [0-255].
+
+       YLOW
+	   Display the Y value at the 10% percentile within the input frame.
+	   Expressed in range of [0-255].
+
+       YAVG
+	   Display the average Y value within the input frame. Expressed in
+	   range of [0-255].
+
+       YHIGH
+	   Display the Y value at the 90% percentile within the input frame.
+	   Expressed in range of [0-255].
+
+       YMAX
+	   Display the maximum Y value contained within the input frame.
+	   Expressed in range of [0-255].
+
+       UMIN
+	   Display the minimal U value contained within the input frame.
+	   Expressed in range of [0-255].
+
+       ULOW
+	   Display the U value at the 10% percentile within the input frame.
+	   Expressed in range of [0-255].
+
+       UAVG
+	   Display the average U value within the input frame. Expressed in
+	   range of [0-255].
+
+       UHIGH
+	   Display the U value at the 90% percentile within the input frame.
+	   Expressed in range of [0-255].
+
+       UMAX
+	   Display the maximum U value contained within the input frame.
+	   Expressed in range of [0-255].
+
+       VMIN
+	   Display the minimal V value contained within the input frame.
+	   Expressed in range of [0-255].
+
+       VLOW
+	   Display the V value at the 10% percentile within the input frame.
+	   Expressed in range of [0-255].
+
+       VAVG
+	   Display the average V value within the input frame. Expressed in
+	   range of [0-255].
+
+       VHIGH
+	   Display the V value at the 90% percentile within the input frame.
+	   Expressed in range of [0-255].
+
+       VMAX
+	   Display the maximum V value contained within the input frame.
+	   Expressed in range of [0-255].
+
+       SATMIN
+	   Display the minimal saturation value contained within the input
+	   frame.  Expressed in range of [0-~181.02].
+
+       SATLOW
+	   Display the saturation value at the 10% percentile within the input
+	   frame.  Expressed in range of [0-~181.02].
+
+       SATAVG
+	   Display the average saturation value within the input frame.
+	   Expressed in range of [0-~181.02].
+
+       SATHIGH
+	   Display the saturation value at the 90% percentile within the input
+	   frame.  Expressed in range of [0-~181.02].
+
+       SATMAX
+	   Display the maximum saturation value contained within the input
+	   frame.  Expressed in range of [0-~181.02].
+
+       HUEMED
+	   Display the median value for hue within the input frame. Expressed
+	   in range of [0-360].
+
+       HUEAVG
+	   Display the average value for hue within the input frame. Expressed
+	   in range of [0-360].
+
+       YDIF
+	   Display the average of sample value difference between all values
+	   of the Y plane in the current frame and corresponding values of the
+	   previous input frame.  Expressed in range of [0-255].
+
+       UDIF
+	   Display the average of sample value difference between all values
+	   of the U plane in the current frame and corresponding values of the
+	   previous input frame.  Expressed in range of [0-255].
+
+       VDIF
+	   Display the average of sample value difference between all values
+	   of the V plane in the current frame and corresponding values of the
+	   previous input frame.  Expressed in range of [0-255].
+
+       YBITDEPTH
+	   Display bit depth of Y plane in current frame.  Expressed in range
+	   of [0-16].
+
+       UBITDEPTH
+	   Display bit depth of U plane in current frame.  Expressed in range
+	   of [0-16].
+
+       VBITDEPTH
+	   Display bit depth of V plane in current frame.  Expressed in range
+	   of [0-16].
+
+       The filter accepts the following options:
+
+       stat
+       out stat specify an additional form of image analysis.  out output
+	   video with the specified type of pixel highlighted.
+
+	   Both options accept the following values:
+
+	   tout
+	       Identify temporal outliers pixels. A temporal outlier is a
+	       pixel unlike the neighboring pixels of the same field. Examples
+	       of temporal outliers include the results of video dropouts,
+	       head clogs, or tape tracking issues.
+
+	   vrep
+	       Identify vertical line repetition. Vertical line repetition
+	       includes similar rows of pixels within a frame. In born-digital
+	       video vertical line repetition is common, but this pattern is
+	       uncommon in video digitized from an analog source. When it
+	       occurs in video that results from the digitization of an analog
+	       source it can indicate concealment from a dropout compensator.
+
+	   brng
+	       Identify pixels that fall outside of legal broadcast range.
+
+       color, c
+	   Set the highlight color for the out option. The default color is
+	   yellow.
+
+       Examples
+
+       o   Output data of various video metrics:
+
+		   ffprobe -f lavfi movie=example.mov,signalstats="stat=tout+vrep+brng" -show_frames
+
+       o   Output specific data about the minimum and maximum values of the Y
+	   plane per frame:
+
+		   ffprobe -f lavfi movie=example.mov,signalstats -show_entries frame_tags=lavfi.signalstats.YMAX,lavfi.signalstats.YMIN
+
+       o   Playback video while highlighting pixels that are outside of
+	   broadcast range in red.
+
+		   ffplay example.mov -vf signalstats="out=brng:color=red"
+
+       o   Playback video with signalstats metadata drawn over the frame.
+
+		   ffplay example.mov -vf signalstats=stat=brng+vrep+tout,drawtext=fontfile=FreeSerif.ttf:textfile=signalstat_drawtext.txt
+
+	   The contents of signalstat_drawtext.txt used in the command are:
+
+		   time %{pts:hms}
+		   Y (%{metadata:lavfi.signalstats.YMIN}-%{metadata:lavfi.signalstats.YMAX})
+		   U (%{metadata:lavfi.signalstats.UMIN}-%{metadata:lavfi.signalstats.UMAX})
+		   V (%{metadata:lavfi.signalstats.VMIN}-%{metadata:lavfi.signalstats.VMAX})
+		   saturation maximum: %{metadata:lavfi.signalstats.SATMAX}
+
+   signature
+       Calculates the MPEG-7 Video Signature. The filter can handle more than
+       one input. In this case the matching between the inputs can be
+       calculated additionally.  The filter always passes through the first
+       input. The signature of each stream can be written into a file.
+
+       It accepts the following options:
+
+       detectmode
+	   Enable or disable the matching process.
+
+	   Available values are:
+
+	   off Disable the calculation of a matching (default).
+
+	   full
+	       Calculate the matching for the whole video and output whether
+	       the whole video matches or only parts.
+
+	   fast
+	       Calculate only until a matching is found or the video ends.
+	       Should be faster in some cases.
+
+       nb_inputs
+	   Set the number of inputs. The option value must be a non negative
+	   integer.  Default value is 1.
+
+       filename
+	   Set the path to which the output is written. If there is more than
+	   one input, the path must be a prototype, i.e. must contain %d or
+	   %0nd (where n is a positive integer), that will be replaced with
+	   the input number. If no filename is specified, no output will be
+	   written. This is the default.
+
+       format
+	   Choose the output format.
+
+	   Available values are:
+
+	   binary
+	       Use the specified binary representation (default).
+
+	   xml Use the specified xml representation.
+
+       th_d
+	   Set threshold to detect one word as similar. The option value must
+	   be an integer greater than zero. The default value is 9000.
+
+       th_dc
+	   Set threshold to detect all words as similar. The option value must
+	   be an integer greater than zero. The default value is 60000.
+
+       th_xh
+	   Set threshold to detect frames as similar. The option value must be
+	   an integer greater than zero. The default value is 116.
+
+       th_di
+	   Set the minimum length of a sequence in frames to recognize it as
+	   matching sequence. The option value must be a non negative integer
+	   value.  The default value is 0.
+
+       th_it
+	   Set the minimum relation, that matching frames to all frames must
+	   have.  The option value must be a double value between 0 and 1. The
+	   default value is 0.5.
+
+       Examples
+
+       o   To calculate the signature of an input video and store it in
+	   signature.bin:
+
+		   ffmpeg -i input.mkv -vf signature=filename=signature.bin -map 0:v -f null -
+
+       o   To detect whether two videos match and store the signatures in XML
+	   format in signature0.xml and signature1.xml:
+
+		   ffmpeg -i input1.mkv -i input2.mkv -filter_complex "[0:v][1:v] signature=nb_inputs=2:detectmode=full:format=xml:filename=signature%d.xml" -map :v -f null -
+
+   siti
+       Calculate Spatial Info (SI) and Temporal Info (TI) scores for a video,
+       as defined in ITU-T P.910: Subjective video quality assessment methods
+       for multimedia applications. Available PDF at
+       <https://www.itu.int/rec/T-REC-P.910-199909-S/en >.
+
+       It accepts the following option:
+
+       print_summary
+	   If set to 1, Summary statistics will be printed to the console.
+	   Default 0.
+
+       Examples
+
+       o   To calculate SI/TI metrics and print summary:
+
+		   ffmpeg -i input.mp4 -vf siti=print_summary=1 -f null -
+
+   smartblur
+       Blur the input video without impacting the outlines.
+
+       It accepts the following options:
+
+       luma_radius, lr
+	   Set the luma radius. The option value must be a float number in the
+	   range [0.1,5.0] that specifies the variance of the gaussian filter
+	   used to blur the image (slower if larger). Default value is 1.0.
+
+       luma_strength, ls
+	   Set the luma strength. The option value must be a float number in
+	   the range [-1.0,1.0] that configures the blurring. A value included
+	   in [0.0,1.0] will blur the image whereas a value included in
+	   [-1.0,0.0] will sharpen the image. Default value is 1.0.
+
+       luma_threshold, lt
+	   Set the luma threshold used as a coefficient to determine whether a
+	   pixel should be blurred or not. The option value must be an integer
+	   in the range [-30,30]. A value of 0 will filter all the image, a
+	   value included in [0,30] will filter flat areas and a value
+	   included in [-30,0] will filter edges. Default value is 0.
+
+       chroma_radius, cr
+	   Set the chroma radius. The option value must be a float number in
+	   the range [0.1,5.0] that specifies the variance of the gaussian
+	   filter used to blur the image (slower if larger). Default value is
+	   luma_radius.
+
+       chroma_strength, cs
+	   Set the chroma strength. The option value must be a float number in
+	   the range [-1.0,1.0] that configures the blurring. A value included
+	   in [0.0,1.0] will blur the image whereas a value included in
+	   [-1.0,0.0] will sharpen the image. Default value is luma_strength.
+
+       chroma_threshold, ct
+	   Set the chroma threshold used as a coefficient to determine whether
+	   a pixel should be blurred or not. The option value must be an
+	   integer in the range [-30,30]. A value of 0 will filter all the
+	   image, a value included in [0,30] will filter flat areas and a
+	   value included in [-30,0] will filter edges. Default value is
+	   luma_threshold.
+
+       If a chroma option is not explicitly set, the corresponding luma value
+       is set.
+
+   sobel
+       Apply sobel operator to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.
+
+       delta
+	   Set value which will be added to filtered result.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   spp
+       Apply a simple postprocessing filter that compresses and decompresses
+       the image at several (or - in the case of quality level 6 - all) shifts
+       and average the results.
+
+       The filter accepts the following options:
+
+       quality
+	   Set quality. This option defines the number of levels for
+	   averaging. It accepts an integer in the range 0-6. If set to 0, the
+	   filter will have no effect. A value of 6 means the higher quality.
+	   For each increment of that value the speed drops by a factor of
+	   approximately 2.  Default value is 3.
+
+       qp  Force a constant quantization parameter. If not set, the filter
+	   will use the QP from the video stream (if available).
+
+       mode
+	   Set thresholding mode. Available modes are:
+
+	   hard
+	       Set hard thresholding (default).
+
+	   soft
+	       Set soft thresholding (better de-ringing effect, but likely
+	       blurrier).
+
+       use_bframe_qp
+	   Enable the use of the QP from the B-Frames if set to 1. Using this
+	   option may cause flicker since the B-Frames have often larger QP.
+	   Default is 0 (not enabled).
+
+       Commands
+
+       This filter supports the following commands:
+
+       quality, level
+	   Set quality level. The value "max" can be used to set the maximum
+	   level, currently 6.
+
+   sr
+       Scale the input by applying one of the super-resolution methods based
+       on convolutional neural networks. Supported models:
+
+       o   Super-Resolution Convolutional Neural Network model (SRCNN).  See
+	   <https://arxiv.org/abs/1501.00092>.
+
+       o   Efficient Sub-Pixel Convolutional Neural Network model (ESPCN).
+	   See <https://arxiv.org/abs/1609.05158>.
+
+       Training scripts as well as scripts for model file (.pb) saving can be
+       found at <https://github.com/XueweiMeng/sr/tree/sr_dnn_native>.
+       Original repository is at
+       <https://github.com/HighVoltageRocknRoll/sr.git>.
+
+       Native model files (.model) can be generated from TensorFlow model
+       files (.pb) by using tools/python/convert.py
+
+       The filter accepts the following options:
+
+       dnn_backend
+	   Specify which DNN backend to use for model loading and execution.
+	   This option accepts the following values:
+
+	   native
+	       Native implementation of DNN loading and execution.
+
+	   tensorflow
+	       TensorFlow backend. To enable this backend you need to install
+	       the TensorFlow for C library (see
+	       <https://www.tensorflow.org/install/lang_c>) and configure
+	       FFmpeg with "--enable-libtensorflow"
+
+	   Default value is native.
+
+       model
+	   Set path to model file specifying network architecture and its
+	   parameters.	Note that different backends use different file
+	   formats. TensorFlow backend can load files for both formats, while
+	   native backend can load files for only its format.
+
+       scale_factor
+	   Set scale factor for SRCNN model. Allowed values are 2, 3 and 4.
+	   Default value is 2. Scale factor is necessary for SRCNN model,
+	   because it accepts input upscaled using bicubic upscaling with
+	   proper scale factor.
+
+       To get full functionality (such as async execution), please use the
+       dnn_processing filter.
+
+   ssim
+       Obtain the SSIM (Structural SImilarity Metric) between two input
+       videos.
+
+       This filter takes in input two input videos, the first input is
+       considered the "main" source and is passed unchanged to the output. The
+       second input is used as a "reference" video for computing the SSIM.
+
+       Both video inputs must have the same resolution and pixel format for
+       this filter to work correctly. Also it assumes that both inputs have
+       the same number of frames, which are compared one by one.
+
+       The filter stores the calculated SSIM of each frame.
+
+       The description of the accepted parameters follows.
+
+       stats_file, f
+	   If specified the filter will use the named file to save the SSIM of
+	   each individual frame. When filename equals "-" the data is sent to
+	   standard output.
+
+       The file printed if stats_file is selected, contains a sequence of
+       key/value pairs of the form key:value for each compared couple of
+       frames.
+
+       A description of each shown parameter follows:
+
+       n   sequential number of the input frame, starting from 1
+
+       Y, U, V, R, G, B
+	   SSIM of the compared frames for the component specified by the
+	   suffix.
+
+       All SSIM of the compared frames for the whole frame.
+
+       dB  Same as above but in dB representation.
+
+       This filter also supports the framesync options.
+
+       Examples
+
+       o   For example:
+
+		   movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
+		   [main][ref] ssim="stats_file=stats.log" [out]
+
+	   On this example the input file being processed is compared with the
+	   reference file ref_movie.mpg. The SSIM of each individual frame is
+	   stored in stats.log.
+
+       o   Another example with both psnr and ssim at same time:
+
+		   ffmpeg -i main.mpg -i ref.mpg -lavfi  "ssim;[0:v][1:v]psnr" -f null -
+
+       o   Another example with different containers:
+
+		   ffmpeg -i main.mpg -i ref.mkv -lavfi  "[0:v]settb=AVTB,setpts=PTS-STARTPTS[main];[1:v]settb=AVTB,setpts=PTS-STARTPTS[ref];[main][ref]ssim" -f null -
+
+   stereo3d
+       Convert between different stereoscopic image formats.
+
+       The filters accept the following options:
+
+       in  Set stereoscopic image format of input.
+
+	   Available values for input image formats are:
+
+	   sbsl
+	       side by side parallel (left eye left, right eye right)
+
+	   sbsr
+	       side by side crosseye (right eye left, left eye right)
+
+	   sbs2l
+	       side by side parallel with half width resolution (left eye
+	       left, right eye right)
+
+	   sbs2r
+	       side by side crosseye with half width resolution (right eye
+	       left, left eye right)
+
+	   abl
+	   tbl above-below (left eye above, right eye below)
+
+	   abr
+	   tbr above-below (right eye above, left eye below)
+
+	   ab2l
+	   tb2l
+	       above-below with half height resolution (left eye above, right
+	       eye below)
+
+	   ab2r
+	   tb2r
+	       above-below with half height resolution (right eye above, left
+	       eye below)
+
+	   al  alternating frames (left eye first, right eye second)
+
+	   ar  alternating frames (right eye first, left eye second)
+
+	   irl interleaved rows (left eye has top row, right eye starts on
+	       next row)
+
+	   irr interleaved rows (right eye has top row, left eye starts on
+	       next row)
+
+	   icl interleaved columns, left eye first
+
+	   icr interleaved columns, right eye first
+
+	       Default value is sbsl.
+
+       out Set stereoscopic image format of output.
+
+	   sbsl
+	       side by side parallel (left eye left, right eye right)
+
+	   sbsr
+	       side by side crosseye (right eye left, left eye right)
+
+	   sbs2l
+	       side by side parallel with half width resolution (left eye
+	       left, right eye right)
+
+	   sbs2r
+	       side by side crosseye with half width resolution (right eye
+	       left, left eye right)
+
+	   abl
+	   tbl above-below (left eye above, right eye below)
+
+	   abr
+	   tbr above-below (right eye above, left eye below)
+
+	   ab2l
+	   tb2l
+	       above-below with half height resolution (left eye above, right
+	       eye below)
+
+	   ab2r
+	   tb2r
+	       above-below with half height resolution (right eye above, left
+	       eye below)
+
+	   al  alternating frames (left eye first, right eye second)
+
+	   ar  alternating frames (right eye first, left eye second)
+
+	   irl interleaved rows (left eye has top row, right eye starts on
+	       next row)
+
+	   irr interleaved rows (right eye has top row, left eye starts on
+	       next row)
+
+	   arbg
+	       anaglyph red/blue gray (red filter on left eye, blue filter on
+	       right eye)
+
+	   argg
+	       anaglyph red/green gray (red filter on left eye, green filter
+	       on right eye)
+
+	   arcg
+	       anaglyph red/cyan gray (red filter on left eye, cyan filter on
+	       right eye)
+
+	   arch
+	       anaglyph red/cyan half colored (red filter on left eye, cyan
+	       filter on right eye)
+
+	   arcc
+	       anaglyph red/cyan color (red filter on left eye, cyan filter on
+	       right eye)
+
+	   arcd
+	       anaglyph red/cyan color optimized with the least squares
+	       projection of dubois (red filter on left eye, cyan filter on
+	       right eye)
+
+	   agmg
+	       anaglyph green/magenta gray (green filter on left eye, magenta
+	       filter on right eye)
+
+	   agmh
+	       anaglyph green/magenta half colored (green filter on left eye,
+	       magenta filter on right eye)
+
+	   agmc
+	       anaglyph green/magenta colored (green filter on left eye,
+	       magenta filter on right eye)
+
+	   agmd
+	       anaglyph green/magenta color optimized with the least squares
+	       projection of dubois (green filter on left eye, magenta filter
+	       on right eye)
+
+	   aybg
+	       anaglyph yellow/blue gray (yellow filter on left eye, blue
+	       filter on right eye)
+
+	   aybh
+	       anaglyph yellow/blue half colored (yellow filter on left eye,
+	       blue filter on right eye)
+
+	   aybc
+	       anaglyph yellow/blue colored (yellow filter on left eye, blue
+	       filter on right eye)
+
+	   aybd
+	       anaglyph yellow/blue color optimized with the least squares
+	       projection of dubois (yellow filter on left eye, blue filter on
+	       right eye)
+
+	   ml  mono output (left eye only)
+
+	   mr  mono output (right eye only)
+
+	   chl checkerboard, left eye first
+
+	   chr checkerboard, right eye first
+
+	   icl interleaved columns, left eye first
+
+	   icr interleaved columns, right eye first
+
+	   hdmi
+	       HDMI frame pack
+
+	   Default value is arcd.
+
+       Examples
+
+       o   Convert input video from side by side parallel to anaglyph
+	   yellow/blue dubois:
+
+		   stereo3d=sbsl:aybd
+
+       o   Convert input video from above below (left eye above, right eye
+	   below) to side by side crosseye.
+
+		   stereo3d=abl:sbsr
+
+   streamselect, astreamselect
+       Select video or audio streams.
+
+       The filter accepts the following options:
+
+       inputs
+	   Set number of inputs. Default is 2.
+
+       map Set input indexes to remap to outputs.
+
+       Commands
+
+       The "streamselect" and "astreamselect" filter supports the following
+       commands:
+
+       map Set input indexes to remap to outputs.
+
+       Examples
+
+       o   Select first 5 seconds 1st stream and rest of time 2nd stream:
+
+		   sendcmd='5.0 streamselect map 1',streamselect=inputs=2:map=0
+
+       o   Same as above, but for audio:
+
+		   asendcmd='5.0 astreamselect map 1',astreamselect=inputs=2:map=0
+
+   subtitles
+       Draw subtitles on top of input video using the libass library.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-libass". This filter also requires a build with libavcodec
+       and libavformat to convert the passed subtitles file to ASS (Advanced
+       Substation Alpha) subtitles format.
+
+       The filter accepts the following options:
+
+       filename, f
+	   Set the filename of the subtitle file to read. It must be
+	   specified.
+
+       original_size
+	   Specify the size of the original video, the video for which the ASS
+	   file was composed. For the syntax of this option, check the "Video
+	   size" section in the ffmpeg-utils manual.  Due to a misdesign in
+	   ASS aspect ratio arithmetic, this is necessary to correctly scale
+	   the fonts if the aspect ratio has been changed.
+
+       fontsdir
+	   Set a directory path containing fonts that can be used by the
+	   filter.  These fonts will be used in addition to whatever the font
+	   provider uses.
+
+       alpha
+	   Process alpha channel, by default alpha channel is untouched.
+
+       charenc
+	   Set subtitles input character encoding. "subtitles" filter only.
+	   Only useful if not UTF-8.
+
+       stream_index, si
+	   Set subtitles stream index. "subtitles" filter only.
+
+       force_style
+	   Override default style or script info parameters of the subtitles.
+	   It accepts a string containing ASS style format "KEY=VALUE" couples
+	   separated by ",".
+
+       If the first key is not specified, it is assumed that the first value
+       specifies the filename.
+
+       For example, to render the file sub.srt on top of the input video, use
+       the command:
+
+	       subtitles=sub.srt
+
+       which is equivalent to:
+
+	       subtitles=filename=sub.srt
+
+       To render the default subtitles stream from file video.mkv, use:
+
+	       subtitles=video.mkv
+
+       To render the second subtitles stream from that file, use:
+
+	       subtitles=video.mkv:si=1
+
+       To make the subtitles stream from sub.srt appear in 80% transparent
+       blue "DejaVu Serif", use:
+
+	       subtitles=sub.srt:force_style='Fontname=DejaVu Serif,PrimaryColour=&HCCFF0000'
+
+   super2xsai
+       Scale the input by 2x and smooth using the Super2xSaI (Scale and
+       Interpolate) pixel art scaling algorithm.
+
+       Useful for enlarging pixel art images without reducing sharpness.
+
+   swaprect
+       Swap two rectangular objects in video.
+
+       This filter accepts the following options:
+
+       w   Set object width.
+
+       h   Set object height.
+
+       x1  Set 1st rect x coordinate.
+
+       y1  Set 1st rect y coordinate.
+
+       x2  Set 2nd rect x coordinate.
+
+       y2  Set 2nd rect y coordinate.
+
+	   All expressions are evaluated once for each frame.
+
+       The all options are expressions containing the following constants:
+
+       w
+       h   The input width and height.
+
+       a   same as w / h
+
+       sar input sample aspect ratio
+
+       dar input display aspect ratio, it is the same as (w / h) * sar
+
+       n   The number of the input frame, starting from 0.
+
+       t   The timestamp expressed in seconds. It's NAN if the input timestamp
+	   is unknown.
+
+       pos the position in the file of the input frame, NAN if unknown
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   swapuv
+       Swap U & V plane.
+
+   tblend
+       Blend successive video frames.
+
+       See blend
+
+   telecine
+       Apply telecine process to the video.
+
+       This filter accepts the following options:
+
+       first_field
+	   top, t
+	       top field first
+
+	   bottom, b
+	       bottom field first The default value is "top".
+
+       pattern
+	   A string of numbers representing the pulldown pattern you wish to
+	   apply.  The default value is 23.
+
+	       Some typical patterns:
+
+	       NTSC output (30i):
+	       27.5p: 32222
+	       24p: 23 (classic)
+	       24p: 2332 (preferred)
+	       20p: 33
+	       18p: 334
+	       16p: 3444
+
+	       PAL output (25i):
+	       27.5p: 12222
+	       24p: 222222222223 ("Euro pulldown")
+	       16.67p: 33
+	       16p: 33333334
+
+   thistogram
+       Compute and draw a color distribution histogram for the input video
+       across time.
+
+       Unlike histogram video filter which only shows histogram of single
+       input frame at certain time, this filter shows also past histograms of
+       number of frames defined by "width" option.
+
+       The computed histogram is a representation of the color component
+       distribution in an image.
+
+       The filter accepts the following options:
+
+       width, w
+	   Set width of single color component output. Default value is 0.
+	   Value of 0 means width will be picked from input video.  This also
+	   set number of passed histograms to keep.  Allowed range is [0,
+	   8192].
+
+       display_mode, d
+	   Set display mode.  It accepts the following values:
+
+	   stack
+	       Per color component graphs are placed below each other.
+
+	   parade
+	       Per color component graphs are placed side by side.
+
+	   overlay
+	       Presents information identical to that in the "parade", except
+	       that the graphs representing color components are superimposed
+	       directly over one another.
+
+	   Default is "stack".
+
+       levels_mode, m
+	   Set mode. Can be either "linear", or "logarithmic".	Default is
+	   "linear".
+
+       components, c
+	   Set what color components to display.  Default is 7.
+
+       bgopacity, b
+	   Set background opacity. Default is 0.9.
+
+       envelope, e
+	   Show envelope. Default is disabled.
+
+       ecolor, ec
+	   Set envelope color. Default is "gold".
+
+       slide
+	   Set slide mode.
+
+	   Available values for slide is:
+
+	   frame
+	       Draw new frame when right border is reached.
+
+	   replace
+	       Replace old columns with new ones.
+
+	   scroll
+	       Scroll from right to left.
+
+	   rscroll
+	       Scroll from left to right.
+
+	   picture
+	       Draw single picture.
+
+	   Default is "replace".
+
+   threshold
+       Apply threshold effect to video stream.
+
+       This filter needs four video streams to perform thresholding.  First
+       stream is stream we are filtering.  Second stream is holding threshold
+       values, third stream is holding min values, and last, fourth stream is
+       holding max values.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+       For example if first stream pixel's component value is less then
+       threshold value of pixel component from 2nd threshold stream, third
+       stream value will picked, otherwise fourth stream pixel component value
+       will be picked.
+
+       Using color source filter one can perform various types of
+       thresholding:
+
+       Commands
+
+       This filter supports the all options as commands.
+
+       Examples
+
+       o   Binary threshold, using gray color as threshold:
+
+		   ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=black -f lavfi -i color=white -lavfi threshold output.avi
+
+       o   Inverted binary threshold, using gray color as threshold:
+
+		   ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -f lavfi -i color=black -lavfi threshold output.avi
+
+       o   Truncate binary threshold, using gray color as threshold:
+
+		   ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=gray -lavfi threshold output.avi
+
+       o   Threshold to zero, using gray color as threshold:
+
+		   ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -i 320x240.avi -lavfi threshold output.avi
+
+       o   Inverted threshold to zero, using gray color as threshold:
+
+		   ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=white -lavfi threshold output.avi
+
+   thumbnail
+       Select the most representative frame in a given sequence of consecutive
+       frames.
+
+       The filter accepts the following options:
+
+       n   Set the frames batch size to analyze; in a set of n frames, the
+	   filter will pick one of them, and then handle the next batch of n
+	   frames until the end. Default is 100.
+
+       log Set the log level to display picked frame stats.  Default is
+	   "info".
+
+       Since the filter keeps track of the whole frames sequence, a bigger n
+       value will result in a higher memory usage, so a high value is not
+       recommended.
+
+       Examples
+
+       o   Extract one picture each 50 frames:
+
+		   thumbnail=50
+
+       o   Complete example of a thumbnail creation with ffmpeg:
+
+		   ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
+
+   tile
+       Tile several successive frames together.
+
+       The untile filter can do the reverse.
+
+       The filter accepts the following options:
+
+       layout
+	   Set the grid size in the form "COLUMNSxROWS". Range is upto
+	   UINT_MAX cells.  Default is "6x5".
+
+       nb_frames
+	   Set the maximum number of frames to render in the given area. It
+	   must be less than or equal to wxh. The default value is 0, meaning
+	   all the area will be used.
+
+       margin
+	   Set the outer border margin in pixels. Range is 0 to 1024. Default
+	   is 0.
+
+       padding
+	   Set the inner border thickness (i.e. the number of pixels between
+	   frames). For more advanced padding options (such as having
+	   different values for the edges), refer to the pad video filter.
+	   Range is 0 to 1024. Default is 0.
+
+       color
+	   Specify the color of the unused area. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.  The
+	   default value of color is "black".
+
+       overlap
+	   Set the number of frames to overlap when tiling several successive
+	   frames together.  The value must be between 0 and nb_frames - 1.
+	   Default is 0.
+
+       init_padding
+	   Set the number of frames to initially be empty before displaying
+	   first output frame.	This controls how soon will one get first
+	   output frame.  The value must be between 0 and nb_frames - 1.
+	   Default is 0.
+
+       Examples
+
+       o   Produce 8x8 PNG tiles of all keyframes (-skip_frame nokey) in a
+	   movie:
+
+		   ffmpeg -skip_frame nokey -i file.avi -vf 'scale=128:72,tile=8x8' -an -vsync 0 keyframes%03d.png
+
+	   The -vsync 0 is necessary to prevent ffmpeg from duplicating each
+	   output frame to accommodate the originally detected frame rate.
+
+       o   Display 5 pictures in an area of "3x2" frames, with 7 pixels
+	   between them, and 2 pixels of initial margin, using mixed flat and
+	   named options:
+
+		   tile=3x2:nb_frames=5:padding=7:margin=2
+
+   tinterlace
+       Perform various types of temporal field interlacing.
+
+       Frames are counted starting from 1, so the first input frame is
+       considered odd.
+
+       The filter accepts the following options:
+
+       mode
+	   Specify the mode of the interlacing. This option can also be
+	   specified as a value alone. See below for a list of values for this
+	   option.
+
+	   Available values are:
+
+	   merge, 0
+	       Move odd frames into the upper field, even into the lower
+	       field, generating a double height frame at half frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+
+		       Output:
+		       11111			       33333
+		       22222			       44444
+		       11111			       33333
+		       22222			       44444
+		       11111			       33333
+		       22222			       44444
+		       11111			       33333
+		       22222			       44444
+
+	   drop_even, 1
+	       Only output odd frames, even frames are dropped, generating a
+	       frame with unchanged height at half frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+
+		       Output:
+		       11111			       33333
+		       11111			       33333
+		       11111			       33333
+		       11111			       33333
+
+	   drop_odd, 2
+	       Only output even frames, odd frames are dropped, generating a
+	       frame with unchanged height at half frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+
+		       Output:
+				       22222			       44444
+				       22222			       44444
+				       22222			       44444
+				       22222			       44444
+
+	   pad, 3
+	       Expand each frame to full height, but pad alternate lines with
+	       black, generating a frame with double height at the same input
+	       frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+
+		       Output:
+		       11111	       .....	       33333	       .....
+		       .....	       22222	       .....	       44444
+		       11111	       .....	       33333	       .....
+		       .....	       22222	       .....	       44444
+		       11111	       .....	       33333	       .....
+		       .....	       22222	       .....	       44444
+		       11111	       .....	       33333	       .....
+		       .....	       22222	       .....	       44444
+
+	   interleave_top, 4
+	       Interleave the upper field from odd frames with the lower field
+	       from even frames, generating a frame with unchanged height at
+	       half frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111<-	       22222	       33333<-	       44444
+		       11111	       22222<-	       33333	       44444<-
+		       11111<-	       22222	       33333<-	       44444
+		       11111	       22222<-	       33333	       44444<-
+
+		       Output:
+		       11111			       33333
+		       22222			       44444
+		       11111			       33333
+		       22222			       44444
+
+	   interleave_bottom, 5
+	       Interleave the lower field from odd frames with the upper field
+	       from even frames, generating a frame with unchanged height at
+	       half frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222<-	       33333	       44444<-
+		       11111<-	       22222	       33333<-	       44444
+		       11111	       22222<-	       33333	       44444<-
+		       11111<-	       22222	       33333<-	       44444
+
+		       Output:
+		       22222			       44444
+		       11111			       33333
+		       22222			       44444
+		       11111			       33333
+
+	   interlacex2, 6
+	       Double frame rate with unchanged height. Frames are inserted
+	       each containing the second temporal field from the previous
+	       input frame and the first temporal field from the next input
+	       frame. This mode relies on the top_field_first flag. Useful for
+	       interlaced video displays with no field synchronisation.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222	       33333	       44444
+			11111		22222		33333		44444
+		       11111	       22222	       33333	       44444
+			11111		22222		33333		44444
+
+		       Output:
+		       11111   22222   22222   33333   33333   44444   44444
+			11111	11111	22222	22222	33333	33333	44444
+		       11111   22222   22222   33333   33333   44444   44444
+			11111	11111	22222	22222	33333	33333	44444
+
+	   mergex2, 7
+	       Move odd frames into the upper field, even into the lower
+	       field, generating a double height frame at same frame rate.
+
+			------> time
+		       Input:
+		       Frame 1	       Frame 2	       Frame 3	       Frame 4
+
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+		       11111	       22222	       33333	       44444
+
+		       Output:
+		       11111	       33333	       33333	       55555
+		       22222	       22222	       44444	       44444
+		       11111	       33333	       33333	       55555
+		       22222	       22222	       44444	       44444
+		       11111	       33333	       33333	       55555
+		       22222	       22222	       44444	       44444
+		       11111	       33333	       33333	       55555
+		       22222	       22222	       44444	       44444
+
+	   Numeric values are deprecated but are accepted for backward
+	   compatibility reasons.
+
+	   Default mode is "merge".
+
+       flags
+	   Specify flags influencing the filter process.
+
+	   Available value for flags is:
+
+	   low_pass_filter, vlpf
+	       Enable linear vertical low-pass filtering in the filter.
+	       Vertical low-pass filtering is required when creating an
+	       interlaced destination from a progressive source which contains
+	       high-frequency vertical detail. Filtering will reduce interlace
+	       'twitter' and Moire patterning.
+
+	   complex_filter, cvlpf
+	       Enable complex vertical low-pass filtering.  This will slightly
+	       less reduce interlace 'twitter' and Moire patterning but better
+	       retain detail and subjective sharpness impression.
+
+	   bypass_il
+	       Bypass already interlaced frames, only adjust the frame rate.
+
+	   Vertical low-pass filtering and bypassing already interlaced frames
+	   can only be enabled for mode interleave_top and interleave_bottom.
+
+   tmedian
+       Pick median pixels from several successive input video frames.
+
+       The filter accepts the following options:
+
+       radius
+	   Set radius of median filter.  Default is 1. Allowed range is from 1
+	   to 127.
+
+       planes
+	   Set which planes to filter. Default value is 15, by which all
+	   planes are processed.
+
+       percentile
+	   Set median percentile. Default value is 0.5.  Default value of 0.5
+	   will pick always median values, while 0 will pick minimum values,
+	   and 1 maximum values.
+
+       Commands
+
+       This filter supports all above options as commands, excluding option
+       "radius".
+
+   tmidequalizer
+       Apply Temporal Midway Video Equalization effect.
+
+       Midway Video Equalization adjusts a sequence of video frames to have
+       the same histograms, while maintaining their dynamics as much as
+       possible. It's useful for e.g. matching exposures from a video frames
+       sequence.
+
+       This filter accepts the following option:
+
+       radius
+	   Set filtering radius. Default is 5. Allowed range is from 1 to 127.
+
+       sigma
+	   Set filtering sigma. Default is 0.5. This controls strength of
+	   filtering.  Setting this option to 0 effectively does nothing.
+
+       planes
+	   Set which planes to process. Default is 15, which is all available
+	   planes.
+
+   tmix
+       Mix successive video frames.
+
+       A description of the accepted options follows.
+
+       frames
+	   The number of successive frames to mix. If unspecified, it defaults
+	   to 3.
+
+       weights
+	   Specify weight of each input video frame.  Each weight is separated
+	   by space. If number of weights is smaller than number of frames
+	   last specified weight will be used for all remaining unset weights.
+
+       scale
+	   Specify scale, if it is set it will be multiplied with sum of each
+	   weight multiplied with pixel values to give final destination pixel
+	   value. By default scale is auto scaled to sum of weights.
+
+       planes
+	   Set which planes to filter. Default is all. Allowed range is from 0
+	   to 15.
+
+       Examples
+
+       o   Average 7 successive frames:
+
+		   tmix=frames=7:weights="1 1 1 1 1 1 1"
+
+       o   Apply simple temporal convolution:
+
+		   tmix=frames=3:weights="-1 3 -1"
+
+       o   Similar as above but only showing temporal differences:
+
+		   tmix=frames=3:weights="-1 2 -1":scale=1
+
+       Commands
+
+       This filter supports the following commands:
+
+       weights
+       scale
+       planes
+	   Syntax is same as option with same name.
+
+   tonemap
+       Tone map colors from different dynamic ranges.
+
+       This filter expects data in single precision floating point, as it
+       needs to operate on (and can output) out-of-range values. Another
+       filter, such as zscale, is needed to convert the resulting frame to a
+       usable format.
+
+       The tonemapping algorithms implemented only work on linear light, so
+       input data should be linearized beforehand (and possibly correctly
+       tagged).
+
+	       ffmpeg -i INPUT -vf zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p OUTPUT
+
+       Options
+
+       The filter accepts the following options.
+
+       tonemap
+	   Set the tone map algorithm to use.
+
+	   Possible values are:
+
+	   none
+	       Do not apply any tone map, only desaturate overbright pixels.
+
+	   clip
+	       Hard-clip any out-of-range values. Use it for perfect color
+	       accuracy for in-range values, while distorting out-of-range
+	       values.
+
+	   linear
+	       Stretch the entire reference gamut to a linear multiple of the
+	       display.
+
+	   gamma
+	       Fit a logarithmic transfer between the tone curves.
+
+	   reinhard
+	       Preserve overall image brightness with a simple curve, using
+	       nonlinear contrast, which results in flattening details and
+	       degrading color accuracy.
+
+	   hable
+	       Preserve both dark and bright details better than reinhard, at
+	       the cost of slightly darkening everything. Use it when detail
+	       preservation is more important than color and brightness
+	       accuracy.
+
+	   mobius
+	       Smoothly map out-of-range values, while retaining contrast and
+	       colors for in-range material as much as possible. Use it when
+	       color accuracy is more important than detail preservation.
+
+	   Default is none.
+
+       param
+	   Tune the tone mapping algorithm.
+
+	   This affects the following algorithms:
+
+	   none
+	       Ignored.
+
+	   linear
+	       Specifies the scale factor to use while stretching.  Default to
+	       1.0.
+
+	   gamma
+	       Specifies the exponent of the function.	Default to 1.8.
+
+	   clip
+	       Specify an extra linear coefficient to multiply into the signal
+	       before clipping.  Default to 1.0.
+
+	   reinhard
+	       Specify the local contrast coefficient at the display peak.
+	       Default to 0.5, which means that in-gamut values will be about
+	       half as bright as when clipping.
+
+	   hable
+	       Ignored.
+
+	   mobius
+	       Specify the transition point from linear to mobius transform.
+	       Every value below this point is guaranteed to be mapped 1:1.
+	       The higher the value, the more accurate the result will be, at
+	       the cost of losing bright details.  Default to 0.3, which due
+	       to the steep initial slope still preserves in-range colors
+	       fairly accurately.
+
+       desat
+	   Apply desaturation for highlights that exceed this level of
+	   brightness. The higher the parameter, the more color information
+	   will be preserved. This setting helps prevent unnaturally blown-out
+	   colors for super-highlights, by (smoothly) turning into white
+	   instead. This makes images feel more natural, at the cost of
+	   reducing information about out-of-range colors.
+
+	   The default of 2.0 is somewhat conservative and will mostly just
+	   apply to skies or directly sunlit surfaces. A setting of 0.0
+	   disables this option.
+
+	   This option works only if the input frame has a supported color
+	   tag.
+
+       peak
+	   Override signal/nominal/reference peak with this value. Useful when
+	   the embedded peak information in display metadata is not reliable
+	   or when tone mapping from a lower range to a higher range.
+
+   tpad
+       Temporarily pad video frames.
+
+       The filter accepts the following options:
+
+       start
+	   Specify number of delay frames before input video stream. Default
+	   is 0.
+
+       stop
+	   Specify number of padding frames after input video stream.  Set to
+	   -1 to pad indefinitely. Default is 0.
+
+       start_mode
+	   Set kind of frames added to beginning of stream.  Can be either add
+	   or clone.  With add frames of solid-color are added.  With clone
+	   frames are clones of first frame.  Default is add.
+
+       stop_mode
+	   Set kind of frames added to end of stream.  Can be either add or
+	   clone.  With add frames of solid-color are added.  With clone
+	   frames are clones of last frame.  Default is add.
+
+       start_duration, stop_duration
+	   Specify the duration of the start/stop delay. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.
+	   These options override start and stop. Default is 0.
+
+       color
+	   Specify the color of the padded area. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+
+	   The default value of color is "black".
+
+   transpose
+       Transpose rows with columns in the input video and optionally flip it.
+
+       It accepts the following parameters:
+
+       dir Specify the transposition direction.
+
+	   Can assume the following values:
+
+	   0, 4, cclock_flip
+	       Rotate by 90 degrees counterclockwise and vertically flip
+	       (default), that is:
+
+		       L.R     L.l
+		       . . ->  . .
+		       l.r     R.r
+
+	   1, 5, clock
+	       Rotate by 90 degrees clockwise, that is:
+
+		       L.R     l.L
+		       . . ->  . .
+		       l.r     r.R
+
+	   2, 6, cclock
+	       Rotate by 90 degrees counterclockwise, that is:
+
+		       L.R     R.r
+		       . . ->  . .
+		       l.r     L.l
+
+	   3, 7, clock_flip
+	       Rotate by 90 degrees clockwise and vertically flip, that is:
+
+		       L.R     r.R
+		       . . ->  . .
+		       l.r     l.L
+
+	   For values between 4-7, the transposition is only done if the input
+	   video geometry is portrait and not landscape. These values are
+	   deprecated, the "passthrough" option should be used instead.
+
+	   Numerical values are deprecated, and should be dropped in favor of
+	   symbolic constants.
+
+       passthrough
+	   Do not apply the transposition if the input geometry matches the
+	   one specified by the specified value. It accepts the following
+	   values:
+
+	   none
+	       Always apply transposition.
+
+	   portrait
+	       Preserve portrait geometry (when height >= width).
+
+	   landscape
+	       Preserve landscape geometry (when width >= height).
+
+	   Default value is "none".
+
+       For example to rotate by 90 degrees clockwise and preserve portrait
+       layout:
+
+	       transpose=dir=1:passthrough=portrait
+
+       The command above can also be specified as:
+
+	       transpose=1:portrait
+
+   transpose_npp
+       Transpose rows with columns in the input video and optionally flip it.
+       For more in depth examples see the transpose video filter, which shares
+       mostly the same options.
+
+       It accepts the following parameters:
+
+       dir Specify the transposition direction.
+
+	   Can assume the following values:
+
+	   cclock_flip
+	       Rotate by 90 degrees counterclockwise and vertically flip.
+	       (default)
+
+	   clock
+	       Rotate by 90 degrees clockwise.
+
+	   cclock
+	       Rotate by 90 degrees counterclockwise.
+
+	   clock_flip
+	       Rotate by 90 degrees clockwise and vertically flip.
+
+       passthrough
+	   Do not apply the transposition if the input geometry matches the
+	   one specified by the specified value. It accepts the following
+	   values:
+
+	   none
+	       Always apply transposition. (default)
+
+	   portrait
+	       Preserve portrait geometry (when height >= width).
+
+	   landscape
+	       Preserve landscape geometry (when width >= height).
+
+   trim
+       Trim the input so that the output contains one continuous subpart of
+       the input.
+
+       It accepts the following parameters:
+
+       start
+	   Specify the time of the start of the kept section, i.e. the frame
+	   with the timestamp start will be the first frame in the output.
+
+       end Specify the time of the first frame that will be dropped, i.e. the
+	   frame immediately preceding the one with the timestamp end will be
+	   the last frame in the output.
+
+       start_pts
+	   This is the same as start, except this option sets the start
+	   timestamp in timebase units instead of seconds.
+
+       end_pts
+	   This is the same as end, except this option sets the end timestamp
+	   in timebase units instead of seconds.
+
+       duration
+	   The maximum duration of the output in seconds.
+
+       start_frame
+	   The number of the first frame that should be passed to the output.
+
+       end_frame
+	   The number of the first frame that should be dropped.
+
+       start, end, and duration are expressed as time duration specifications;
+       see the Time duration section in the ffmpeg-utils(1) manual for the
+       accepted syntax.
+
+       Note that the first two sets of the start/end options and the duration
+       option look at the frame timestamp, while the _frame variants simply
+       count the frames that pass through the filter. Also note that this
+       filter does not modify the timestamps. If you wish for the output
+       timestamps to start at zero, insert a setpts filter after the trim
+       filter.
+
+       If multiple start or end options are set, this filter tries to be
+       greedy and keep all the frames that match at least one of the specified
+       constraints. To keep only the part that matches all the constraints at
+       once, chain multiple trim filters.
+
+       The defaults are such that all the input is kept. So it is possible to
+       set e.g.  just the end values to keep everything before the specified
+       time.
+
+       Examples:
+
+       o   Drop everything except the second minute of input:
+
+		   ffmpeg -i INPUT -vf trim=60:120
+
+       o   Keep only the first second:
+
+		   ffmpeg -i INPUT -vf trim=duration=1
+
+   unpremultiply
+       Apply alpha unpremultiply effect to input video stream using first
+       plane of second stream as alpha.
+
+       Both streams must have same dimensions and same pixel format.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes will be processed, unprocessed planes will be
+	   copied.  By default value 0xf, all planes will be processed.
+
+	   If the format has 1 or 2 components, then luma is bit 0.  If the
+	   format has 3 or 4 components: for RGB formats bit 0 is green, bit 1
+	   is blue and bit 2 is red; for YUV formats bit 0 is luma, bit 1 is
+	   chroma-U and bit 2 is chroma-V.  If present, the alpha channel is
+	   always the last bit.
+
+       inplace
+	   Do not require 2nd input for processing, instead use alpha plane
+	   from input stream.
+
+   unsharp
+       Sharpen or blur the input video.
+
+       It accepts the following parameters:
+
+       luma_msize_x, lx
+	   Set the luma matrix horizontal size. It must be an odd integer
+	   between 3 and 23. The default value is 5.
+
+       luma_msize_y, ly
+	   Set the luma matrix vertical size. It must be an odd integer
+	   between 3 and 23. The default value is 5.
+
+       luma_amount, la
+	   Set the luma effect strength. It must be a floating point number,
+	   reasonable values lay between -1.5 and 1.5.
+
+	   Negative values will blur the input video, while positive values
+	   will sharpen it, a value of zero will disable the effect.
+
+	   Default value is 1.0.
+
+       chroma_msize_x, cx
+	   Set the chroma matrix horizontal size. It must be an odd integer
+	   between 3 and 23. The default value is 5.
+
+       chroma_msize_y, cy
+	   Set the chroma matrix vertical size. It must be an odd integer
+	   between 3 and 23. The default value is 5.
+
+       chroma_amount, ca
+	   Set the chroma effect strength. It must be a floating point number,
+	   reasonable values lay between -1.5 and 1.5.
+
+	   Negative values will blur the input video, while positive values
+	   will sharpen it, a value of zero will disable the effect.
+
+	   Default value is 0.0.
+
+       alpha_msize_x, ax
+	   Set the alpha matrix horizontal size. It must be an odd integer
+	   between 3 and 23. The default value is 5.
+
+       alpha_msize_y, ay
+	   Set the alpha matrix vertical size. It must be an odd integer
+	   between 3 and 23. The default value is 5.
+
+       alpha_amount, aa
+	   Set the alpha effect strength. It must be a floating point number,
+	   reasonable values lay between -1.5 and 1.5.
+
+	   Negative values will blur the input video, while positive values
+	   will sharpen it, a value of zero will disable the effect.
+
+	   Default value is 0.0.
+
+       All parameters are optional and default to the equivalent of the string
+       '5:5:1.0:5:5:0.0'.
+
+       Examples
+
+       o   Apply strong luma sharpen effect:
+
+		   unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
+
+       o   Apply a strong blur of both luma and chroma parameters:
+
+		   unsharp=7:7:-2:7:7:-2
+
+   untile
+       Decompose a video made of tiled images into the individual images.
+
+       The frame rate of the output video is the frame rate of the input video
+       multiplied by the number of tiles.
+
+       This filter does the reverse of tile.
+
+       The filter accepts the following options:
+
+       layout
+	   Set the grid size (i.e. the number of lines and columns). For the
+	   syntax of this option, check the "Video size" section in the
+	   ffmpeg-utils manual.
+
+       Examples
+
+       o   Produce a 1-second video from a still image file made of 25 frames
+	   stacked vertically, like an analogic film reel:
+
+		   ffmpeg -r 1 -i image.jpg -vf untile=1x25 movie.mkv
+
+   uspp
+       Apply ultra slow/simple postprocessing filter that compresses and
+       decompresses the image at several (or - in the case of quality level 8
+       - all) shifts and average the results.
+
+       The way this differs from the behavior of spp is that uspp actually
+       encodes & decodes each case with libavcodec Snow, whereas spp uses a
+       simplified intra only 8x8 DCT similar to MJPEG.
+
+       This filter is only available in ffmpeg version 4.4 or earlier.
+
+       The filter accepts the following options:
+
+       quality
+	   Set quality. This option defines the number of levels for
+	   averaging. It accepts an integer in the range 0-8. If set to 0, the
+	   filter will have no effect. A value of 8 means the higher quality.
+	   For each increment of that value the speed drops by a factor of
+	   approximately 2.  Default value is 3.
+
+       qp  Force a constant quantization parameter. If not set, the filter
+	   will use the QP from the video stream (if available).
+
+   v360
+       Convert 360 videos between various formats.
+
+       The filter accepts the following options:
+
+       input
+       output
+	   Set format of the input/output video.
+
+	   Available formats:
+
+	   e
+	   equirect
+	       Equirectangular projection.
+
+	   c3x2
+	   c6x1
+	   c1x6
+	       Cubemap with 3x2/6x1/1x6 layout.
+
+	       Format specific options:
+
+	       in_pad
+	       out_pad
+		   Set padding proportion for the input/output cubemap. Values
+		   in decimals.
+
+		   Example values:
+
+		   0   No padding.
+
+		   0.01
+		       1% of face is padding. For example, with 1920x1280
+		       resolution face size would be 640x640 and padding would
+		       be 3 pixels from each side. (640 * 0.01 = 6 pixels)
+
+		   Default value is @samp{0}.  Maximum value is @samp{0.1}.
+
+	       fin_pad
+	       fout_pad
+		   Set fixed padding for the input/output cubemap. Values in
+		   pixels.
+
+		   Default value is @samp{0}. If greater than zero it
+		   overrides other padding options.
+
+	       in_forder
+	       out_forder
+		   Set order of faces for the input/output cubemap. Choose one
+		   direction for each position.
+
+		   Designation of directions:
+
+		   r   right
+
+		   l   left
+
+		   u   up
+
+		   d   down
+
+		   f   forward
+
+		   b   back
+
+		   Default value is @samp{rludfb}.
+
+	       in_frot
+	       out_frot
+		   Set rotation of faces for the input/output cubemap. Choose
+		   one angle for each position.
+
+		   Designation of angles:
+
+		   0   0 degrees clockwise
+
+		   1   90 degrees clockwise
+
+		   2   180 degrees clockwise
+
+		   3   270 degrees clockwise
+
+		   Default value is @samp{000000}.
+
+	   eac Equi-Angular Cubemap.
+
+	   flat
+	   gnomonic
+	   rectilinear
+	       Regular video.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   dfisheye
+	       Dual fisheye.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   barrel
+	   fb
+	   barrelsplit
+	       Facebook's 360 formats.
+
+	   sg  Stereographic format.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   mercator
+	       Mercator format.
+
+	   ball
+	       Ball format, gives significant distortion toward the back.
+
+	   hammer
+	       Hammer-Aitoff map projection format.
+
+	   sinusoidal
+	       Sinusoidal map projection format.
+
+	   fisheye
+	       Fisheye projection.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   pannini
+	       Pannini projection.
+
+	       Format specific options:
+
+	       h_fov
+		   Set output pannini parameter.
+
+	       ih_fov
+		   Set input pannini parameter.
+
+	   cylindrical
+	       Cylindrical projection.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   perspective
+	       Perspective projection. (output only)
+
+	       Format specific options:
+
+	       v_fov
+		   Set perspective parameter.
+
+	   tetrahedron
+	       Tetrahedron projection.
+
+	   tsp Truncated square pyramid projection.
+
+	   he
+	   hequirect
+	       Half equirectangular projection.
+
+	   equisolid
+	       Equisolid format.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   og  Orthographic format.
+
+	       Format specific options:
+
+	       h_fov
+	       v_fov
+	       d_fov
+		   Set output horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	       ih_fov
+	       iv_fov
+	       id_fov
+		   Set input horizontal/vertical/diagonal field of view.
+		   Values in degrees.
+
+		   If diagonal field of view is set it overrides horizontal
+		   and vertical field of view.
+
+	   octahedron
+	       Octahedron projection.
+
+	   cylindricalea
+	       Cylindrical Equal Area projection.
+
+       interp
+	   Set interpolation method.Note: more complex interpolation methods
+	   require much more memory to run.
+
+	   Available methods:
+
+	   near
+	   nearest
+	       Nearest neighbour.
+
+	   line
+	   linear
+	       Bilinear interpolation.
+
+	   lagrange9
+	       Lagrange9 interpolation.
+
+	   cube
+	   cubic
+	       Bicubic interpolation.
+
+	   lanc
+	   lanczos
+	       Lanczos interpolation.
+
+	   sp16
+	   spline16
+	       Spline16 interpolation.
+
+	   gauss
+	   gaussian
+	       Gaussian interpolation.
+
+	   mitchell
+	       Mitchell interpolation.
+
+	   Default value is @samp{line}.
+
+       w
+       h   Set the output video resolution.
+
+	   Default resolution depends on formats.
+
+       in_stereo
+       out_stereo
+	   Set the input/output stereo format.
+
+	   2d  2D mono
+
+	   sbs Side by side
+
+	   tb  Top bottom
+
+	   Default value is @samp{2d} for input and output format.
+
+       yaw
+       pitch
+       roll
+	   Set rotation for the output video. Values in degrees.
+
+       rorder
+	   Set rotation order for the output video. Choose one item for each
+	   position.
+
+	   y, Y
+	       yaw
+
+	   p, P
+	       pitch
+
+	   r, R
+	       roll
+
+	   Default value is @samp{ypr}.
+
+       h_flip
+       v_flip
+       d_flip
+	   Flip the output video horizontally(swaps
+	   left-right)/vertically(swaps up-down)/in-depth(swaps back-forward).
+	   Boolean values.
+
+       ih_flip
+       iv_flip
+	   Set if input video is flipped horizontally/vertically. Boolean
+	   values.
+
+       in_trans
+	   Set if input video is transposed. Boolean value, by default
+	   disabled.
+
+       out_trans
+	   Set if output video needs to be transposed. Boolean value, by
+	   default disabled.
+
+       h_offset
+       v_offset
+	   Set output horizontal/vertical off-axis offset. Default is set to
+	   0.  Allowed range is from -1 to 1.
+
+       alpha_mask
+	   Build mask in alpha plane for all unmapped pixels by marking them
+	   fully transparent. Boolean value, by default disabled.
+
+       reset_rot
+	   Reset rotation of output video. Boolean value, by default disabled.
+
+       Examples
+
+       o   Convert equirectangular video to cubemap with 3x2 layout and 1%
+	   padding using bicubic interpolation:
+
+		   ffmpeg -i input.mkv -vf v360=e:c3x2:cubic:out_pad=0.01 output.mkv
+
+       o   Extract back view of Equi-Angular Cubemap:
+
+		   ffmpeg -i input.mkv -vf v360=eac:flat:yaw=180 output.mkv
+
+       o   Convert transposed and horizontally flipped Equi-Angular Cubemap in
+	   side-by-side stereo format to equirectangular top-bottom stereo
+	   format:
+
+		   v360=eac:equirect:in_stereo=sbs:in_trans=1:ih_flip=1:out_stereo=tb
+
+       Commands
+
+       This filter supports subset of above options as commands.
+
+   vaguedenoiser
+       Apply a wavelet based denoiser.
+
+       It transforms each frame from the video input into the wavelet domain,
+       using Cohen-Daubechies-Feauveau 9/7. Then it applies some filtering to
+       the obtained coefficients. It does an inverse wavelet transform after.
+       Due to wavelet properties, it should give a nice smoothed result, and
+       reduced noise, without blurring picture features.
+
+       This filter accepts the following options:
+
+       threshold
+	   The filtering strength. The higher, the more filtered the video
+	   will be.  Hard thresholding can use a higher threshold than soft
+	   thresholding before the video looks overfiltered. Default value is
+	   2.
+
+       method
+	   The filtering method the filter will use.
+
+	   It accepts the following values:
+
+	   hard
+	       All values under the threshold will be zeroed.
+
+	   soft
+	       All values under the threshold will be zeroed. All values above
+	       will be reduced by the threshold.
+
+	   garrote
+	       Scales or nullifies coefficients - intermediary between (more)
+	       soft and (less) hard thresholding.
+
+	   Default is garrote.
+
+       nsteps
+	   Number of times, the wavelet will decompose the picture. Picture
+	   can't be decomposed beyond a particular point (typically, 8 for a
+	   640x480 frame - as 2^9 = 512 > 480). Valid values are integers
+	   between 1 and 32. Default value is 6.
+
+       percent
+	   Partial of full denoising (limited coefficients shrinking), from 0
+	   to 100. Default value is 85.
+
+       planes
+	   A list of the planes to process. By default all planes are
+	   processed.
+
+       type
+	   The threshold type the filter will use.
+
+	   It accepts the following values:
+
+	   universal
+	       Threshold used is same for all decompositions.
+
+	   bayes
+	       Threshold used depends also on each decomposition coefficients.
+
+	   Default is universal.
+
+   varblur
+       Apply variable blur filter by using 2nd video stream to set blur
+       radius.	The 2nd stream must have the same dimensions.
+
+       This filter accepts the following options:
+
+       min_r
+	   Set min allowed radius. Allowed range is from 0 to 254. Default is
+	   0.
+
+       max_r
+	   Set max allowed radius. Allowed range is from 1 to 255. Default is
+	   8.
+
+       planes
+	   Set which planes to process. By default, all are used.
+
+       The "varblur" filter also supports the framesync options.
+
+       Commands
+
+       This filter supports all the above options as commands.
+
+   vectorscope
+       Display 2 color component values in the two dimensional graph (which is
+       called a vectorscope).
+
+       This filter accepts the following options:
+
+       mode, m
+	   Set vectorscope mode.
+
+	   It accepts the following values:
+
+	   gray
+	   tint
+	       Gray values are displayed on graph, higher brightness means
+	       more pixels have same component color value on location in
+	       graph. This is the default mode.
+
+	   color
+	       Gray values are displayed on graph. Surrounding pixels values
+	       which are not present in video frame are drawn in gradient of 2
+	       color components which are set by option "x" and "y". The 3rd
+	       color component is static.
+
+	   color2
+	       Actual color components values present in video frame are
+	       displayed on graph.
+
+	   color3
+	       Similar as color2 but higher frequency of same values "x" and
+	       "y" on graph increases value of another color component, which
+	       is luminance by default values of "x" and "y".
+
+	   color4
+	       Actual colors present in video frame are displayed on graph. If
+	       two different colors map to same position on graph then color
+	       with higher value of component not present in graph is picked.
+
+	   color5
+	       Gray values are displayed on graph. Similar to "color" but with
+	       3rd color component picked from radial gradient.
+
+       x   Set which color component will be represented on X-axis. Default is
+	   1.
+
+       y   Set which color component will be represented on Y-axis. Default is
+	   2.
+
+       intensity, i
+	   Set intensity, used by modes: gray, color, color3 and color5 for
+	   increasing brightness of color component which represents frequency
+	   of (X, Y) location in graph.
+
+       envelope, e
+	   none
+	       No envelope, this is default.
+
+	   instant
+	       Instant envelope, even darkest single pixel will be clearly
+	       highlighted.
+
+	   peak
+	       Hold maximum and minimum values presented in graph over time.
+	       This way you can still spot out of range values without
+	       constantly looking at vectorscope.
+
+	   peak+instant
+	       Peak and instant envelope combined together.
+
+       graticule, g
+	   Set what kind of graticule to draw.
+
+	   none
+	   green
+	   color
+	   invert
+       opacity, o
+	   Set graticule opacity.
+
+       flags, f
+	   Set graticule flags.
+
+	   white
+	       Draw graticule for white point.
+
+	   black
+	       Draw graticule for black point.
+
+	   name
+	       Draw color points short names.
+
+       bgopacity, b
+	   Set background opacity.
+
+       lthreshold, l
+	   Set low threshold for color component not represented on X or Y
+	   axis.  Values lower than this value will be ignored. Default is 0.
+	   Note this value is multiplied with actual max possible value one
+	   pixel component can have. So for 8-bit input and low threshold
+	   value of 0.1 actual threshold is 0.1 * 255 = 25.
+
+       hthreshold, h
+	   Set high threshold for color component not represented on X or Y
+	   axis.  Values higher than this value will be ignored. Default is 1.
+	   Note this value is multiplied with actual max possible value one
+	   pixel component can have. So for 8-bit input and high threshold
+	   value of 0.9 actual threshold is 0.9 * 255 = 230.
+
+       colorspace, c
+	   Set what kind of colorspace to use when drawing graticule.
+
+	   auto
+	   601
+	   709
+
+	   Default is auto.
+
+       tint0, t0
+       tint1, t1
+	   Set color tint for gray/tint vectorscope mode. By default both
+	   options are zero.  This means no tint, and output will remain gray.
+
+   vidstabdetect
+       Analyze video stabilization/deshaking. Perform pass 1 of 2, see
+       vidstabtransform for pass 2.
+
+       This filter generates a file with relative translation and rotation
+       transform information about subsequent frames, which is then used by
+       the vidstabtransform filter.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-libvidstab".
+
+       This filter accepts the following options:
+
+       result
+	   Set the path to the file used to write the transforms information.
+	   Default value is transforms.trf.
+
+       shakiness
+	   Set how shaky the video is and how quick the camera is. It accepts
+	   an integer in the range 1-10, a value of 1 means little shakiness,
+	   a value of 10 means strong shakiness. Default value is 5.
+
+       accuracy
+	   Set the accuracy of the detection process. It must be a value in
+	   the range 1-15. A value of 1 means low accuracy, a value of 15
+	   means high accuracy. Default value is 15.
+
+       stepsize
+	   Set stepsize of the search process. The region around minimum is
+	   scanned with 1 pixel resolution. Default value is 6.
+
+       mincontrast
+	   Set minimum contrast. Below this value a local measurement field is
+	   discarded. Must be a floating point value in the range 0-1. Default
+	   value is 0.3.
+
+       tripod
+	   Set reference frame number for tripod mode.
+
+	   If enabled, the motion of the frames is compared to a reference
+	   frame in the filtered stream, identified by the specified number.
+	   The idea is to compensate all movements in a more-or-less static
+	   scene and keep the camera view absolutely still.
+
+	   If set to 0, it is disabled. The frames are counted starting from
+	   1.
+
+       show
+	   Show fields and transforms in the resulting frames. It accepts an
+	   integer in the range 0-2. Default value is 0, which disables any
+	   visualization.
+
+       Examples
+
+       o   Use default values:
+
+		   vidstabdetect
+
+       o   Analyze strongly shaky movie and put the results in file
+	   mytransforms.trf:
+
+		   vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
+
+       o   Visualize the result of internal transformations in the resulting
+	   video:
+
+		   vidstabdetect=show=1
+
+       o   Analyze a video with medium shakiness using ffmpeg:
+
+		   ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
+
+   vidstabtransform
+       Video stabilization/deshaking: pass 2 of 2, see vidstabdetect for pass
+       1.
+
+       Read a file with transform information for each frame and
+       apply/compensate them. Together with the vidstabdetect filter this can
+       be used to deshake videos. See also
+       <http://public.hronopik.de/vid.stab>. It is important to also use the
+       unsharp filter, see below.
+
+       To enable compilation of this filter you need to configure FFmpeg with
+       "--enable-libvidstab".
+
+       Options
+
+       input
+	   Set path to the file used to read the transforms. Default value is
+	   transforms.trf.
+
+       smoothing
+	   Set the number of frames (value*2 + 1) used for lowpass filtering
+	   the camera movements. Default value is 10.
+
+	   For example a number of 10 means that 21 frames are used (10 in the
+	   past and 10 in the future) to smoothen the motion in the video. A
+	   larger value leads to a smoother video, but limits the acceleration
+	   of the camera (pan/tilt movements). 0 is a special case where a
+	   static camera is simulated.
+
+       optalgo
+	   Set the camera path optimization algorithm.
+
+	   Accepted values are:
+
+	   gauss
+	       gaussian kernel low-pass filter on camera motion (default)
+
+	   avg averaging on transformations
+
+       maxshift
+	   Set maximal number of pixels to translate frames. Default value is
+	   -1, meaning no limit.
+
+       maxangle
+	   Set maximal angle in radians (degree*PI/180) to rotate frames.
+	   Default value is -1, meaning no limit.
+
+       crop
+	   Specify how to deal with borders that may be visible due to
+	   movement compensation.
+
+	   Available values are:
+
+	   keep
+	       keep image information from previous frame (default)
+
+	   black
+	       fill the border black
+
+       invert
+	   Invert transforms if set to 1. Default value is 0.
+
+       relative
+	   Consider transforms as relative to previous frame if set to 1,
+	   absolute if set to 0. Default value is 0.
+
+       zoom
+	   Set percentage to zoom. A positive value will result in a zoom-in
+	   effect, a negative value in a zoom-out effect. Default value is 0
+	   (no zoom).
+
+       optzoom
+	   Set optimal zooming to avoid borders.
+
+	   Accepted values are:
+
+	   0   disabled
+
+	   1   optimal static zoom value is determined (only very strong
+	       movements will lead to visible borders) (default)
+
+	   2   optimal adaptive zoom value is determined (no borders will be
+	       visible), see zoomspeed
+
+	   Note that the value given at zoom is added to the one calculated
+	   here.
+
+       zoomspeed
+	   Set percent to zoom maximally each frame (enabled when optzoom is
+	   set to 2). Range is from 0 to 5, default value is 0.25.
+
+       interpol
+	   Specify type of interpolation.
+
+	   Available values are:
+
+	   no  no interpolation
+
+	   linear
+	       linear only horizontal
+
+	   bilinear
+	       linear in both directions (default)
+
+	   bicubic
+	       cubic in both directions (slow)
+
+       tripod
+	   Enable virtual tripod mode if set to 1, which is equivalent to
+	   "relative=0:smoothing=0". Default value is 0.
+
+	   Use also "tripod" option of vidstabdetect.
+
+       debug
+	   Increase log verbosity if set to 1. Also the detected global
+	   motions are written to the temporary file global_motions.trf.
+	   Default value is 0.
+
+       Examples
+
+       o   Use ffmpeg for a typical stabilization with default values:
+
+		   ffmpeg -i inp.mpeg -vf vidstabtransform,unsharp=5:5:0.8:3:3:0.4 inp_stabilized.mpeg
+
+	   Note the use of the unsharp filter which is always recommended.
+
+       o   Zoom in a bit more and load transform data from a given file:
+
+		   vidstabtransform=zoom=5:input="mytransforms.trf"
+
+       o   Smoothen the video even more:
+
+		   vidstabtransform=smoothing=30
+
+   vflip
+       Flip the input video vertically.
+
+       For example, to vertically flip a video with ffmpeg:
+
+	       ffmpeg -i in.avi -vf "vflip" out.avi
+
+   vfrdet
+       Detect variable frame rate video.
+
+       This filter tries to detect if the input is variable or constant frame
+       rate.
+
+       At end it will output number of frames detected as having variable
+       delta pts, and ones with constant delta pts.  If there was frames with
+       variable delta, than it will also show min, max and average delta
+       encountered.
+
+   vibrance
+       Boost or alter saturation.
+
+       The filter accepts the following options:
+
+       intensity
+	   Set strength of boost if positive value or strength of alter if
+	   negative value.  Default is 0. Allowed range is from -2 to 2.
+
+       rbal
+	   Set the red balance. Default is 1. Allowed range is from -10 to 10.
+
+       gbal
+	   Set the green balance. Default is 1. Allowed range is from -10 to
+	   10.
+
+       bbal
+	   Set the blue balance. Default is 1. Allowed range is from -10 to
+	   10.
+
+       rlum
+	   Set the red luma coefficient.
+
+       glum
+	   Set the green luma coefficient.
+
+       blum
+	   Set the blue luma coefficient.
+
+       alternate
+	   If "intensity" is negative and this is set to 1, colors will
+	   change, otherwise colors will be less saturated, more towards gray.
+
+       Commands
+
+       This filter supports the all above options as commands.
+
+   vif
+       Obtain the average VIF (Visual Information Fidelity) between two input
+       videos.
+
+       This filter takes two input videos.
+
+       Both input videos must have the same resolution and pixel format for
+       this filter to work correctly. Also it assumes that both inputs have
+       the same number of frames, which are compared one by one.
+
+       The obtained average VIF score is printed through the logging system.
+
+       The filter stores the calculated VIF score of each frame.
+
+       This filter also supports the framesync options.
+
+       In the below example the input file main.mpg being processed is
+       compared with the reference file ref.mpg.
+
+	       ffmpeg -i main.mpg -i ref.mpg -lavfi vif -f null -
+
+   vignette
+       Make or reverse a natural vignetting effect.
+
+       The filter accepts the following options:
+
+       angle, a
+	   Set lens angle expression as a number of radians.
+
+	   The value is clipped in the "[0,PI/2]" range.
+
+	   Default value: "PI/5"
+
+       x0
+       y0  Set center coordinates expressions. Respectively "w/2" and "h/2" by
+	   default.
+
+       mode
+	   Set forward/backward mode.
+
+	   Available modes are:
+
+	   forward
+	       The larger the distance from the central point, the darker the
+	       image becomes.
+
+	   backward
+	       The larger the distance from the central point, the brighter
+	       the image becomes.  This can be used to reverse a vignette
+	       effect, though there is no automatic detection to extract the
+	       lens angle and other settings (yet). It can also be used to
+	       create a burning effect.
+
+	   Default value is forward.
+
+       eval
+	   Set evaluation mode for the expressions (angle, x0, y0).
+
+	   It accepts the following values:
+
+	   init
+	       Evaluate expressions only once during the filter
+	       initialization.
+
+	   frame
+	       Evaluate expressions for each incoming frame. This is way
+	       slower than the init mode since it requires all the scalers to
+	       be re-computed, but it allows advanced dynamic expressions.
+
+	   Default value is init.
+
+       dither
+	   Set dithering to reduce the circular banding effects. Default is 1
+	   (enabled).
+
+       aspect
+	   Set vignette aspect. This setting allows one to adjust the shape of
+	   the vignette.  Setting this value to the SAR of the input will make
+	   a rectangular vignetting following the dimensions of the video.
+
+	   Default is "1/1".
+
+       Expressions
+
+       The alpha, x0 and y0 expressions can contain the following parameters.
+
+       w
+       h   input width and height
+
+       n   the number of input frame, starting from 0
+
+       pts the PTS (Presentation TimeStamp) time of the filtered video frame,
+	   expressed in TB units, NAN if undefined
+
+       r   frame rate of the input video, NAN if the input frame rate is
+	   unknown
+
+       t   the PTS (Presentation TimeStamp) of the filtered video frame,
+	   expressed in seconds, NAN if undefined
+
+       tb  time base of the input video
+
+       Examples
+
+       o   Apply simple strong vignetting effect:
+
+		   vignette=PI/4
+
+       o   Make a flickering vignetting:
+
+		   vignette='PI/4+random(1)*PI/50':eval=frame
+
+   vmafmotion
+       Obtain the average VMAF motion score of a video.  It is one of the
+       component metrics of VMAF.
+
+       The obtained average motion score is printed through the logging
+       system.
+
+       The filter accepts the following options:
+
+       stats_file
+	   If specified, the filter will use the named file to save the motion
+	   score of each frame with respect to the previous frame.  When
+	   filename equals "-" the data is sent to standard output.
+
+       Example:
+
+	       ffmpeg -i ref.mpg -vf vmafmotion -f null -
+
+   vstack
+       Stack input videos vertically.
+
+       All streams must be of same pixel format and of same width.
+
+       Note that this filter is faster than using overlay and pad filter to
+       create same output.
+
+       The filter accepts the following options:
+
+       inputs
+	   Set number of input streams. Default is 2.
+
+       shortest
+	   If set to 1, force the output to terminate when the shortest input
+	   terminates. Default value is 0.
+
+   w3fdif
+       Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
+       Deinterlacing Filter").
+
+       Based on the process described by Martin Weston for BBC R&D, and
+       implemented based on the de-interlace algorithm written by Jim
+       Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter uses
+       filter coefficients calculated by BBC R&D.
+
+       This filter uses field-dominance information in frame to decide which
+       of each pair of fields to place first in the output.  If it gets it
+       wrong use setfield filter before "w3fdif" filter.
+
+       There are two sets of filter coefficients, so called "simple" and
+       "complex". Which set of filter coefficients is used can be set by
+       passing an optional parameter:
+
+       filter
+	   Set the interlacing filter coefficients. Accepts one of the
+	   following values:
+
+	   simple
+	       Simple filter coefficient set.
+
+	   complex
+	       More-complex filter coefficient set.
+
+	   Default value is complex.
+
+       mode
+	   The interlacing mode to adopt. It accepts one of the following
+	   values:
+
+	   frame
+	       Output one frame for each frame.
+
+	   field
+	       Output one frame for each field.
+
+	   The default value is "field".
+
+       parity
+	   The picture field parity assumed for the input interlaced video. It
+	   accepts one of the following values:
+
+	   tff Assume the top field is first.
+
+	   bff Assume the bottom field is first.
+
+	   auto
+	       Enable automatic detection of field parity.
+
+	   The default value is "auto".  If the interlacing is unknown or the
+	   decoder does not export this information, top field first will be
+	   assumed.
+
+       deint
+	   Specify which frames to deinterlace. Accepts one of the following
+	   values:
+
+	   all Deinterlace all frames,
+
+	   interlaced
+	       Only deinterlace frames marked as interlaced.
+
+	   Default value is all.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   waveform
+       Video waveform monitor.
+
+       The waveform monitor plots color component intensity. By default
+       luminance only. Each column of the waveform corresponds to a column of
+       pixels in the source video.
+
+       It accepts the following options:
+
+       mode, m
+	   Can be either "row", or "column". Default is "column".  In row
+	   mode, the graph on the left side represents color component value 0
+	   and the right side represents value = 255. In column mode, the top
+	   side represents color component value = 0 and bottom side
+	   represents value = 255.
+
+       intensity, i
+	   Set intensity. Smaller values are useful to find out how many
+	   values of the same luminance are distributed across input
+	   rows/columns.  Default value is 0.04. Allowed range is [0, 1].
+
+       mirror, r
+	   Set mirroring mode. 0 means unmirrored, 1 means mirrored.  In
+	   mirrored mode, higher values will be represented on the left side
+	   for "row" mode and at the top for "column" mode. Default is 1
+	   (mirrored).
+
+       display, d
+	   Set display mode.  It accepts the following values:
+
+	   overlay
+	       Presents information identical to that in the "parade", except
+	       that the graphs representing color components are superimposed
+	       directly over one another.
+
+	       This display mode makes it easier to spot relative differences
+	       or similarities in overlapping areas of the color components
+	       that are supposed to be identical, such as neutral whites,
+	       grays, or blacks.
+
+	   stack
+	       Display separate graph for the color components side by side in
+	       "row" mode or one below the other in "column" mode.
+
+	   parade
+	       Display separate graph for the color components side by side in
+	       "column" mode or one below the other in "row" mode.
+
+	       Using this display mode makes it easy to spot color casts in
+	       the highlights and shadows of an image, by comparing the
+	       contours of the top and the bottom graphs of each waveform.
+	       Since whites, grays, and blacks are characterized by exactly
+	       equal amounts of red, green, and blue, neutral areas of the
+	       picture should display three waveforms of roughly equal
+	       width/height. If not, the correction is easy to perform by
+	       making level adjustments the three waveforms.
+
+	   Default is "stack".
+
+       components, c
+	   Set which color components to display. Default is 1, which means
+	   only luminance or red color component if input is in RGB
+	   colorspace. If is set for example to 7 it will display all 3 (if)
+	   available color components.
+
+       envelope, e
+	   none
+	       No envelope, this is default.
+
+	   instant
+	       Instant envelope, minimum and maximum values presented in graph
+	       will be easily visible even with small "step" value.
+
+	   peak
+	       Hold minimum and maximum values presented in graph across time.
+	       This way you can still spot out of range values without
+	       constantly looking at waveforms.
+
+	   peak+instant
+	       Peak and instant envelope combined together.
+
+       filter, f
+	   lowpass
+	       No filtering, this is default.
+
+	   flat
+	       Luma and chroma combined together.
+
+	   aflat
+	       Similar as above, but shows difference between blue and red
+	       chroma.
+
+	   xflat
+	       Similar as above, but use different colors.
+
+	   yflat
+	       Similar as above, but again with different colors.
+
+	   chroma
+	       Displays only chroma.
+
+	   color
+	       Displays actual color value on waveform.
+
+	   acolor
+	       Similar as above, but with luma showing frequency of chroma
+	       values.
+
+       graticule, g
+	   Set which graticule to display.
+
+	   none
+	       Do not display graticule.
+
+	   green
+	       Display green graticule showing legal broadcast ranges.
+
+	   orange
+	       Display orange graticule showing legal broadcast ranges.
+
+	   invert
+	       Display invert graticule showing legal broadcast ranges.
+
+       opacity, o
+	   Set graticule opacity.
+
+       flags, fl
+	   Set graticule flags.
+
+	   numbers
+	       Draw numbers above lines. By default enabled.
+
+	   dots
+	       Draw dots instead of lines.
+
+       scale, s
+	   Set scale used for displaying graticule.
+
+	   digital
+	   millivolts
+	   ire
+
+	   Default is digital.
+
+       bgopacity, b
+	   Set background opacity.
+
+       tint0, t0
+       tint1, t1
+	   Set tint for output.  Only used with lowpass filter and when
+	   display is not overlay and input pixel formats are not RGB.
+
+       fitmode, fm
+	   Set sample aspect ratio of video output frames.  Can be used to
+	   configure waveform so it is not streched too much in one of
+	   directions.
+
+	   none
+	       Set sample aspect ration to 1/1.
+
+	   size
+	       Set sample aspect ratio to match input size of video
+
+	   Default is none.
+
+   weave, doubleweave
+       The "weave" takes a field-based video input and join each two
+       sequential fields into single frame, producing a new double height clip
+       with half the frame rate and half the frame count.
+
+       The "doubleweave" works same as "weave" but without halving frame rate
+       and frame count.
+
+       It accepts the following option:
+
+       first_field
+	   Set first field. Available values are:
+
+	   top, t
+	       Set the frame as top-field-first.
+
+	   bottom, b
+	       Set the frame as bottom-field-first.
+
+       Examples
+
+       o   Interlace video using select and separatefields filter:
+
+		   separatefields,select=eq(mod(n,4),0)+eq(mod(n,4),3),weave
+
+   xbr
+       Apply the xBR high-quality magnification filter which is designed for
+       pixel art. It follows a set of edge-detection rules, see
+       <https://forums.libretro.com/t/xbr-algorithm-tutorial/123>.
+
+       It accepts the following option:
+
+       n   Set the scaling dimension: 2 for "2xBR", 3 for "3xBR" and 4 for
+	   "4xBR".  Default is 3.
+
+   xcorrelate
+       Apply normalized cross-correlation between first and second input video
+       stream.
+
+       Second input video stream dimensions must be lower than first input
+       video stream.
+
+       The filter accepts the following options:
+
+       planes
+	   Set which planes to process.
+
+       secondary
+	   Set which secondary video frames will be processed from second
+	   input video stream, can be first or all. Default is all.
+
+       The "xcorrelate" filter also supports the framesync options.
+
+   xfade
+       Apply cross fade from one input video stream to another input video
+       stream.	The cross fade is applied for specified duration.
+
+       Both inputs must be constant frame-rate and have the same resolution,
+       pixel format, frame rate and timebase.
+
+       The filter accepts the following options:
+
+       transition
+	   Set one of available transition effects:
+
+	   custom
+	   fade
+	   wipeleft
+	   wiperight
+	   wipeup
+	   wipedown
+	   slideleft
+	   slideright
+	   slideup
+	   slidedown
+	   circlecrop
+	   rectcrop
+	   distance
+	   fadeblack
+	   fadewhite
+	   radial
+	   smoothleft
+	   smoothright
+	   smoothup
+	   smoothdown
+	   circleopen
+	   circleclose
+	   vertopen
+	   vertclose
+	   horzopen
+	   horzclose
+	   dissolve
+	   pixelize
+	   diagtl
+	   diagtr
+	   diagbl
+	   diagbr
+	   hlslice
+	   hrslice
+	   vuslice
+	   vdslice
+	   hblur
+	   fadegrays
+	   wipetl
+	   wipetr
+	   wipebl
+	   wipebr
+	   squeezeh
+	   squeezev
+	   zoomin
+	   fadefast
+	   fadeslow
+
+	   Default transition effect is fade.
+
+       duration
+	   Set cross fade duration in seconds.	Range is 0 to 60 seconds.
+	   Default duration is 1 second.
+
+       offset
+	   Set cross fade start relative to first input stream in seconds.
+	   Default offset is 0.
+
+       expr
+	   Set expression for custom transition effect.
+
+	   The expressions can use the following variables and functions:
+
+	   X
+	   Y   The coordinates of the current sample.
+
+	   W
+	   H   The width and height of the image.
+
+	   P   Progress of transition effect.
+
+	   PLANE
+	       Currently processed plane.
+
+	   A   Return value of first input at current location and plane.
+
+	   B   Return value of second input at current location and plane.
+
+	   a0(x, y)
+	   a1(x, y)
+	   a2(x, y)
+	   a3(x, y)
+	       Return the value of the pixel at location (x,y) of the
+	       first/second/third/fourth component of first input.
+
+	   b0(x, y)
+	   b1(x, y)
+	   b2(x, y)
+	   b3(x, y)
+	       Return the value of the pixel at location (x,y) of the
+	       first/second/third/fourth component of second input.
+
+       Examples
+
+       o   Cross fade from one input video to another input video, with fade
+	   transition and duration of transition of 2 seconds starting at
+	   offset of 5 seconds:
+
+		   ffmpeg -i first.mp4 -i second.mp4 -filter_complex xfade=transition=fade:duration=2:offset=5 output.mp4
+
+   xmedian
+       Pick median pixels from several input videos.
+
+       The filter accepts the following options:
+
+       inputs
+	   Set number of inputs.  Default is 3. Allowed range is from 3 to
+	   255.  If number of inputs is even number, than result will be mean
+	   value between two median values.
+
+       planes
+	   Set which planes to filter. Default value is 15, by which all
+	   planes are processed.
+
+       percentile
+	   Set median percentile. Default value is 0.5.  Default value of 0.5
+	   will pick always median values, while 0 will pick minimum values,
+	   and 1 maximum values.
+
+       Commands
+
+       This filter supports all above options as commands, excluding option
+       "inputs".
+
+   xstack
+       Stack video inputs into custom layout.
+
+       All streams must be of same pixel format.
+
+       The filter accepts the following options:
+
+       inputs
+	   Set number of input streams. Default is 2.
+
+       layout
+	   Specify layout of inputs.  This option requires the desired layout
+	   configuration to be explicitly set by the user.  This sets position
+	   of each video input in output. Each input is separated by '|'.  The
+	   first number represents the column, and the second number
+	   represents the row.	Numbers start at 0 and are separated by '_'.
+	   Optionally one can use wX and hX, where X is video input from which
+	   to take width or height.  Multiple values can be used when
+	   separated by '+'. In such case values are summed together.
+
+	   Note that if inputs are of different sizes gaps may appear, as not
+	   all of the output video frame will be filled. Similarly, videos can
+	   overlap each other if their position doesn't leave enough space for
+	   the full frame of adjoining videos.
+
+	   For 2 inputs, a default layout of "0_0|w0_0" (equivalent to
+	   "grid=2x1") is set. In all other cases, a layout or a grid must be
+	   set by the user. Either "grid" or "layout" can be specified at a
+	   time.  Specifying both will result in an error.
+
+       grid
+	   Specify a fixed size grid of inputs.  This option is used to create
+	   a fixed size grid of the input streams. Set the grid size in the
+	   form "COLUMNSxROWS". There must be "ROWS * COLUMNS" input streams
+	   and they will be arranged as a grid with "ROWS" rows and "COLUMNS"
+	   columns. When using this option, each input stream within a row
+	   must have the same height and all the rows must have the same
+	   width.
+
+	   If "grid" is set, then "inputs" option is ignored and is implicitly
+	   set to "ROWS * COLUMNS".
+
+	   For 2 inputs, a default grid of "2x1" (equivalent to
+	   "layout=0_0|w0_0") is set. In all other cases, a layout or a grid
+	   must be set by the user. Either "grid" or "layout" can be specified
+	   at a time.  Specifying both will result in an error.
+
+       shortest
+	   If set to 1, force the output to terminate when the shortest input
+	   terminates. Default value is 0.
+
+       fill
+	   If set to valid color, all unused pixels will be filled with that
+	   color.  By default fill is set to none, so it is disabled.
+
+       Examples
+
+       o   Display 4 inputs into 2x2 grid.
+
+	   Layout:
+
+		   input1(0, 0)  | input3(w0, 0)
+		   input2(0, h0) | input4(w0, h0)
+
+		   xstack=inputs=4:layout=0_0|0_h0|w0_0|w0_h0
+
+	   Note that if inputs are of different sizes, gaps or overlaps may
+	   occur.
+
+       o   Display 4 inputs into 1x4 grid.
+
+	   Layout:
+
+		   input1(0, 0)
+		   input2(0, h0)
+		   input3(0, h0+h1)
+		   input4(0, h0+h1+h2)
+
+		   xstack=inputs=4:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2
+
+	   Note that if inputs are of different widths, unused space will
+	   appear.
+
+       o   Display 9 inputs into 3x3 grid.
+
+	   Layout:
+
+		   input1(0, 0)       | input4(w0, 0)	   | input7(w0+w3, 0)
+		   input2(0, h0)      | input5(w0, h0)	   | input8(w0+w3, h0)
+		   input3(0, h0+h1)   | input6(w0, h0+h1)  | input9(w0+w3, h0+h1)
+
+		   xstack=inputs=9:layout=0_0|0_h0|0_h0+h1|w0_0|w0_h0|w0_h0+h1|w0+w3_0|w0+w3_h0|w0+w3_h0+h1
+
+	   Note that if inputs are of different sizes, gaps or overlaps may
+	   occur.
+
+       o   Display 16 inputs into 4x4 grid.
+
+	   Layout:
+
+		   input1(0, 0)       | input5(w0, 0)	    | input9 (w0+w4, 0)       | input13(w0+w4+w8, 0)
+		   input2(0, h0)      | input6(w0, h0)	    | input10(w0+w4, h0)      | input14(w0+w4+w8, h0)
+		   input3(0, h0+h1)   | input7(w0, h0+h1)   | input11(w0+w4, h0+h1)   | input15(w0+w4+w8, h0+h1)
+		   input4(0, h0+h1+h2)| input8(w0, h0+h1+h2)| input12(w0+w4, h0+h1+h2)| input16(w0+w4+w8, h0+h1+h2)
+
+		   xstack=inputs=16:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2|w0_0|w0_h0|w0_h0+h1|w0_h0+h1+h2|w0+w4_0|
+		   w0+w4_h0|w0+w4_h0+h1|w0+w4_h0+h1+h2|w0+w4+w8_0|w0+w4+w8_h0|w0+w4+w8_h0+h1|w0+w4+w8_h0+h1+h2
+
+	   Note that if inputs are of different sizes, gaps or overlaps may
+	   occur.
+
+   yadif
+       Deinterlace the input video ("yadif" means "yet another deinterlacing
+       filter").
+
+       It accepts the following parameters:
+
+       mode
+	   The interlacing mode to adopt. It accepts one of the following
+	   values:
+
+	   0, send_frame
+	       Output one frame for each frame.
+
+	   1, send_field
+	       Output one frame for each field.
+
+	   2, send_frame_nospatial
+	       Like "send_frame", but it skips the spatial interlacing check.
+
+	   3, send_field_nospatial
+	       Like "send_field", but it skips the spatial interlacing check.
+
+	   The default value is "send_frame".
+
+       parity
+	   The picture field parity assumed for the input interlaced video. It
+	   accepts one of the following values:
+
+	   0, tff
+	       Assume the top field is first.
+
+	   1, bff
+	       Assume the bottom field is first.
+
+	   -1, auto
+	       Enable automatic detection of field parity.
+
+	   The default value is "auto".  If the interlacing is unknown or the
+	   decoder does not export this information, top field first will be
+	   assumed.
+
+       deint
+	   Specify which frames to deinterlace. Accepts one of the following
+	   values:
+
+	   0, all
+	       Deinterlace all frames.
+
+	   1, interlaced
+	       Only deinterlace frames marked as interlaced.
+
+	   The default value is "all".
+
+   yadif_cuda
+       Deinterlace the input video using the yadif algorithm, but implemented
+       in CUDA so that it can work as part of a GPU accelerated pipeline with
+       nvdec and/or nvenc.
+
+       It accepts the following parameters:
+
+       mode
+	   The interlacing mode to adopt. It accepts one of the following
+	   values:
+
+	   0, send_frame
+	       Output one frame for each frame.
+
+	   1, send_field
+	       Output one frame for each field.
+
+	   2, send_frame_nospatial
+	       Like "send_frame", but it skips the spatial interlacing check.
+
+	   3, send_field_nospatial
+	       Like "send_field", but it skips the spatial interlacing check.
+
+	   The default value is "send_frame".
+
+       parity
+	   The picture field parity assumed for the input interlaced video. It
+	   accepts one of the following values:
+
+	   0, tff
+	       Assume the top field is first.
+
+	   1, bff
+	       Assume the bottom field is first.
+
+	   -1, auto
+	       Enable automatic detection of field parity.
+
+	   The default value is "auto".  If the interlacing is unknown or the
+	   decoder does not export this information, top field first will be
+	   assumed.
+
+       deint
+	   Specify which frames to deinterlace. Accepts one of the following
+	   values:
+
+	   0, all
+	       Deinterlace all frames.
+
+	   1, interlaced
+	       Only deinterlace frames marked as interlaced.
+
+	   The default value is "all".
+
+   yaepblur
+       Apply blur filter while preserving edges ("yaepblur" means "yet another
+       edge preserving blur filter").  The algorithm is described in "J. S.
+       Lee, Digital image enhancement and noise filtering by use of local
+       statistics, IEEE Trans. Pattern Anal. Mach. Intell. PAMI-2, 1980."
+
+       It accepts the following parameters:
+
+       radius, r
+	   Set the window radius. Default value is 3.
+
+       planes, p
+	   Set which planes to filter. Default is only the first plane.
+
+       sigma, s
+	   Set blur strength. Default value is 128.
+
+       Commands
+
+       This filter supports same commands as options.
+
+   zoompan
+       Apply Zoom & Pan effect.
+
+       This filter accepts the following options:
+
+       zoom, z
+	   Set the zoom expression. Range is 1-10. Default is 1.
+
+       x
+       y   Set the x and y expression. Default is 0.
+
+       d   Set the duration expression in number of frames.  This sets for how
+	   many number of frames effect will last for single input image.
+	   Default is 90.
+
+       s   Set the output image size, default is 'hd720'.
+
+       fps Set the output frame rate, default is '25'.
+
+       Each expression can contain the following constants:
+
+       in_w, iw
+	   Input width.
+
+       in_h, ih
+	   Input height.
+
+       out_w, ow
+	   Output width.
+
+       out_h, oh
+	   Output height.
+
+       in  Input frame count.
+
+       on  Output frame count.
+
+       in_time, it
+	   The input timestamp expressed in seconds. It's NAN if the input
+	   timestamp is unknown.
+
+       out_time, time, ot
+	   The output timestamp expressed in seconds.
+
+       x
+       y   Last calculated 'x' and 'y' position from 'x' and 'y' expression
+	   for current input frame.
+
+       px
+       py  'x' and 'y' of last output frame of previous input frame or 0 when
+	   there was not yet such frame (first input frame).
+
+       zoom
+	   Last calculated zoom from 'z' expression for current input frame.
+
+       pzoom
+	   Last calculated zoom of last output frame of previous input frame.
+
+       duration
+	   Number of output frames for current input frame. Calculated from
+	   'd' expression for each input frame.
+
+       pduration
+	   number of output frames created for previous input frame
+
+       a   Rational number: input width / input height
+
+       sar sample aspect ratio
+
+       dar display aspect ratio
+
+       Examples
+
+       o   Zoom in up to 1.5x and pan at same time to some spot near center of
+	   picture:
+
+		   zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
+
+       o   Zoom in up to 1.5x and pan always at center of picture:
+
+		   zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
+
+       o   Same as above but without pausing:
+
+		   zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
+
+       o   Zoom in 2x into center of picture only for the first second of the
+	   input video:
+
+		   zoompan=z='if(between(in_time,0,1),2,1)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
+
+   zscale
+       Scale (resize) the input video, using the z.lib library:
+       <https://github.com/sekrit-twc/zimg>. To enable compilation of this
+       filter, you need to configure FFmpeg with "--enable-libzimg".
+
+       The zscale filter forces the output display aspect ratio to be the same
+       as the input, by changing the output sample aspect ratio.
+
+       If the input image format is different from the format requested by the
+       next filter, the zscale filter will convert the input to the requested
+       format.
+
+       Options
+
+       The filter accepts the following options.
+
+       width, w
+       height, h
+	   Set the output video dimension expression. Default value is the
+	   input dimension.
+
+	   If the width or w value is 0, the input width is used for the
+	   output. If the height or h value is 0, the input height is used for
+	   the output.
+
+	   If one and only one of the values is -n with n >= 1, the zscale
+	   filter will use a value that maintains the aspect ratio of the
+	   input image, calculated from the other specified dimension. After
+	   that it will, however, make sure that the calculated dimension is
+	   divisible by n and adjust the value if necessary.
+
+	   If both values are -n with n >= 1, the behavior will be identical
+	   to both values being set to 0 as previously detailed.
+
+	   See below for the list of accepted constants for use in the
+	   dimension expression.
+
+       size, s
+	   Set the video size. For the syntax of this option, check the "Video
+	   size" section in the ffmpeg-utils manual.
+
+       dither, d
+	   Set the dither type.
+
+	   Possible values are:
+
+	   none
+	   ordered
+	   random
+	   error_diffusion
+
+	   Default is none.
+
+       filter, f
+	   Set the resize filter type.
+
+	   Possible values are:
+
+	   point
+	   bilinear
+	   bicubic
+	   spline16
+	   spline36
+	   lanczos
+
+	   Default is bilinear.
+
+       range, r
+	   Set the color range.
+
+	   Possible values are:
+
+	   input
+	   limited
+	   full
+
+	   Default is same as input.
+
+       primaries, p
+	   Set the color primaries.
+
+	   Possible values are:
+
+	   input
+	   709
+	   unspecified
+	   170m
+	   240m
+	   2020
+
+	   Default is same as input.
+
+       transfer, t
+	   Set the transfer characteristics.
+
+	   Possible values are:
+
+	   input
+	   709
+	   unspecified
+	   601
+	   linear
+	   2020_10
+	   2020_12
+	   smpte2084
+	   iec61966-2-1
+	   arib-std-b67
+
+	   Default is same as input.
+
+       matrix, m
+	   Set the colorspace matrix.
+
+	   Possible value are:
+
+	   input
+	   709
+	   unspecified
+	   470bg
+	   170m
+	   2020_ncl
+	   2020_cl
+
+	   Default is same as input.
+
+       rangein, rin
+	   Set the input color range.
+
+	   Possible values are:
+
+	   input
+	   limited
+	   full
+
+	   Default is same as input.
+
+       primariesin, pin
+	   Set the input color primaries.
+
+	   Possible values are:
+
+	   input
+	   709
+	   unspecified
+	   170m
+	   240m
+	   2020
+
+	   Default is same as input.
+
+       transferin, tin
+	   Set the input transfer characteristics.
+
+	   Possible values are:
+
+	   input
+	   709
+	   unspecified
+	   601
+	   linear
+	   2020_10
+	   2020_12
+
+	   Default is same as input.
+
+       matrixin, min
+	   Set the input colorspace matrix.
+
+	   Possible value are:
+
+	   input
+	   709
+	   unspecified
+	   470bg
+	   170m
+	   2020_ncl
+	   2020_cl
+       chromal, c
+	   Set the output chroma location.
+
+	   Possible values are:
+
+	   input
+	   left
+	   center
+	   topleft
+	   top
+	   bottomleft
+	   bottom
+       chromalin, cin
+	   Set the input chroma location.
+
+	   Possible values are:
+
+	   input
+	   left
+	   center
+	   topleft
+	   top
+	   bottomleft
+	   bottom
+       npl Set the nominal peak luminance.
+
+       param_a
+	   Parameter A for scaling filters. Parameter "b" for bicubic, and the
+	   number of filter taps for lanczos.
+
+       param_b
+	   Parameter B for scaling filters. Parameter "c" for bicubic.
+
+       The values of the w and h options are expressions containing the
+       following constants:
+
+       in_w
+       in_h
+	   The input width and height
+
+       iw
+       ih  These are the same as in_w and in_h.
+
+       out_w
+       out_h
+	   The output (scaled) width and height
+
+       ow
+       oh  These are the same as out_w and out_h
+
+       a   The same as iw / ih
+
+       sar input sample aspect ratio
+
+       dar The input display aspect ratio. Calculated from "(iw / ih) * sar".
+
+       hsub
+       vsub
+	   horizontal and vertical input chroma subsample values. For example
+	   for the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       ohsub
+       ovsub
+	   horizontal and vertical output chroma subsample values. For example
+	   for the pixel format "yuv422p" hsub is 2 and vsub is 1.
+
+       Commands
+
+       This filter supports the following commands:
+
+       width, w
+       height, h
+	   Set the output video dimension expression.  The command accepts the
+	   same syntax of the corresponding option.
+
+	   If the specified expression is not valid, it is kept at its current
+	   value.
+
+OPENCL VIDEO FILTERS
+       Below is a description of the currently available OpenCL video filters.
+
+       To enable compilation of these filters you need to configure FFmpeg
+       with "--enable-opencl".
+
+       Running OpenCL filters requires you to initialize a hardware device and
+       to pass that device to all filters in any filter graph.
+
+       -init_hw_device opencl[=name][:device[,key=value...]]
+	   Initialise a new hardware device of type opencl called name, using
+	   the given device parameters.
+
+       -filter_hw_device name
+	   Pass the hardware device called name to all filters in any filter
+	   graph.
+
+       For more detailed information see
+       <https://www.ffmpeg.org/ffmpeg.html#Advanced-Video-options>
+
+       o   Example of choosing the first device on the second platform and
+	   running avgblur_opencl filter with default parameters on it.
+
+		   -init_hw_device opencl=gpu:1.0 -filter_hw_device gpu -i INPUT -vf "hwupload, avgblur_opencl, hwdownload" OUTPUT
+
+       Since OpenCL filters are not able to access frame data in normal
+       memory, all frame data needs to be uploaded(hwupload) to hardware
+       surfaces connected to the appropriate device before being used and then
+       downloaded(hwdownload) back to normal memory. Note that hwupload will
+       upload to a surface with the same layout as the software frame, so it
+       may be necessary to add a format filter immediately before to get the
+       input into the right format and hwdownload does not support all formats
+       on the output - it may be necessary to insert an additional format
+       filter immediately following in the graph to get the output in a
+       supported format.
+
+   avgblur_opencl
+       Apply average blur filter.
+
+       The filter accepts the following options:
+
+       sizeX
+	   Set horizontal radius size.	Range is "[1, 1024]" and default value
+	   is 1.
+
+       planes
+	   Set which planes to filter. Default value is 0xf, by which all
+	   planes are processed.
+
+       sizeY
+	   Set vertical radius size. Range is "[1, 1024]" and default value is
+	   0. If zero, "sizeX" value will be used.
+
+       Example
+
+       o   Apply average blur filter with horizontal and vertical size of 3,
+	   setting each pixel of the output to the average value of the 7x7
+	   region centered on it in the input. For pixels on the edges of the
+	   image, the region does not extend beyond the image boundaries, and
+	   so out-of-range coordinates are not used in the calculations.
+
+		   -i INPUT -vf "hwupload, avgblur_opencl=3, hwdownload" OUTPUT
+
+   boxblur_opencl
+       Apply a boxblur algorithm to the input video.
+
+       It accepts the following parameters:
+
+       luma_radius, lr
+       luma_power, lp
+       chroma_radius, cr
+       chroma_power, cp
+       alpha_radius, ar
+       alpha_power, ap
+
+       A description of the accepted options follows.
+
+       luma_radius, lr
+       chroma_radius, cr
+       alpha_radius, ar
+	   Set an expression for the box radius in pixels used for blurring
+	   the corresponding input plane.
+
+	   The radius value must be a non-negative number, and must not be
+	   greater than the value of the expression "min(w,h)/2" for the luma
+	   and alpha planes, and of "min(cw,ch)/2" for the chroma planes.
+
+	   Default value for luma_radius is "2". If not specified,
+	   chroma_radius and alpha_radius default to the corresponding value
+	   set for luma_radius.
+
+	   The expressions can contain the following constants:
+
+	   w
+	   h   The input width and height in pixels.
+
+	   cw
+	   ch  The input chroma image width and height in pixels.
+
+	   hsub
+	   vsub
+	       The horizontal and vertical chroma subsample values. For
+	       example, for the pixel format "yuv422p", hsub is 2 and vsub is
+	       1.
+
+       luma_power, lp
+       chroma_power, cp
+       alpha_power, ap
+	   Specify how many times the boxblur filter is applied to the
+	   corresponding plane.
+
+	   Default value for luma_power is 2. If not specified, chroma_power
+	   and alpha_power default to the corresponding value set for
+	   luma_power.
+
+	   A value of 0 will disable the effect.
+
+       Examples
+
+       Apply boxblur filter, setting each pixel of the output to the average
+       value of box-radiuses luma_radius, chroma_radius, alpha_radius for each
+       plane respectively. The filter will apply luma_power, chroma_power,
+       alpha_power times onto the corresponding plane. For pixels on the edges
+       of the image, the radius does not extend beyond the image boundaries,
+       and so out-of-range coordinates are not used in the calculations.
+
+       o   Apply a boxblur filter with the luma, chroma, and alpha radius set
+	   to 2 and luma, chroma, and alpha power set to 3. The filter will
+	   run 3 times with box-radius set to 2 for every plane of the image.
+
+		   -i INPUT -vf "hwupload, boxblur_opencl=luma_radius=2:luma_power=3, hwdownload" OUTPUT
+		   -i INPUT -vf "hwupload, boxblur_opencl=2:3, hwdownload" OUTPUT
+
+       o   Apply a boxblur filter with luma radius set to 2, luma_power to 1,
+	   chroma_radius to 4, chroma_power to 5, alpha_radius to 3 and
+	   alpha_power to 7.
+
+	   For the luma plane, a 2x2 box radius will be run once.
+
+	   For the chroma plane, a 4x4 box radius will be run 5 times.
+
+	   For the alpha plane, a 3x3 box radius will be run 7 times.
+
+		   -i INPUT -vf "hwupload, boxblur_opencl=2:1:4:5:3:7, hwdownload" OUTPUT
+
+   colorkey_opencl
+       RGB colorspace color keying.
+
+       The filter accepts the following options:
+
+       color
+	   The color which will be replaced with transparency.
+
+       similarity
+	   Similarity percentage with the key color.
+
+	   0.01 matches only the exact key color, while 1.0 matches
+	   everything.
+
+       blend
+	   Blend percentage.
+
+	   0.0 makes pixels either fully transparent, or not transparent at
+	   all.
+
+	   Higher values result in semi-transparent pixels, with a higher
+	   transparency the more similar the pixels color is to the key color.
+
+       Examples
+
+       o   Make every semi-green pixel in the input transparent with some
+	   slight blending:
+
+		   -i INPUT -vf "hwupload, colorkey_opencl=green:0.3:0.1, hwdownload" OUTPUT
+
+   convolution_opencl
+       Apply convolution of 3x3, 5x5, 7x7 matrix.
+
+       The filter accepts the following options:
+
+       0m
+       1m
+       2m
+       3m  Set matrix for each plane.  Matrix is sequence of 9, 25 or 49
+	   signed numbers.  Default value for each plane is "0 0 0 0 1 0 0 0
+	   0".
+
+       0rdiv
+       1rdiv
+       2rdiv
+       3rdiv
+	   Set multiplier for calculated value for each plane.	If unset or 0,
+	   it will be sum of all matrix elements.  The option value must be a
+	   float number greater or equal to 0.0. Default value is 1.0.
+
+       0bias
+       1bias
+       2bias
+       3bias
+	   Set bias for each plane. This value is added to the result of the
+	   multiplication.  Useful for making the overall image brighter or
+	   darker.  The option value must be a float number greater or equal
+	   to 0.0. Default value is 0.0.
+
+       Examples
+
+       o   Apply sharpen:
+
+		   -i INPUT -vf "hwupload, convolution_opencl=0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0, hwdownload" OUTPUT
+
+       o   Apply blur:
+
+		   -i INPUT -vf "hwupload, convolution_opencl=1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9, hwdownload" OUTPUT
+
+       o   Apply edge enhance:
+
+		   -i INPUT -vf "hwupload, convolution_opencl=0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128, hwdownload" OUTPUT
+
+       o   Apply edge detect:
+
+		   -i INPUT -vf "hwupload, convolution_opencl=0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128, hwdownload" OUTPUT
+
+       o   Apply laplacian edge detector which includes diagonals:
+
+		   -i INPUT -vf "hwupload, convolution_opencl=1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:1 1 1 1 -8 1 1 1 1:5:5:5:1:0:128:128:0, hwdownload" OUTPUT
+
+       o   Apply emboss:
+
+		   -i INPUT -vf "hwupload, convolution_opencl=-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2, hwdownload" OUTPUT
+
+   erosion_opencl
+       Apply erosion effect to the video.
+
+       This filter replaces the pixel by the local(3x3) minimum.
+
+       It accepts the following options:
+
+       threshold0
+       threshold1
+       threshold2
+       threshold3
+	   Limit the maximum change for each plane. Range is "[0, 65535]" and
+	   default value is 65535.  If 0, plane will remain unchanged.
+
+       coordinates
+	   Flag which specifies the pixel to refer to.	Range is "[0, 255]"
+	   and default value is 255, i.e. all eight pixels are used.
+
+	   Flags to local 3x3 coordinates region centered on "x":
+
+	       1 2 3
+
+	       4 x 5
+
+	       6 7 8
+
+       Example
+
+       o   Apply erosion filter with threshold0 set to 30, threshold1 set 40,
+	   threshold2 set to 50 and coordinates set to 231, setting each pixel
+	   of the output to the local minimum between pixels: 1, 2, 3, 6, 7, 8
+	   of the 3x3 region centered on it in the input. If the difference
+	   between input pixel and local minimum is more then threshold of the
+	   corresponding plane, output pixel will be set to input pixel -
+	   threshold of corresponding plane.
+
+		   -i INPUT -vf "hwupload, erosion_opencl=30:40:50:coordinates=231, hwdownload" OUTPUT
+
+   deshake_opencl
+       Feature-point based video stabilization filter.
+
+       The filter accepts the following options:
+
+       tripod
+	   Simulates a tripod by preventing any camera movement whatsoever
+	   from the original frame. Defaults to 0.
+
+       debug
+	   Whether or not additional debug info should be displayed, both in
+	   the processed output and in the console.
+
+	   Note that in order to see console debug output you will also need
+	   to pass "-v verbose" to ffmpeg.
+
+	   Viewing point matches in the output video is only supported for RGB
+	   input.
+
+	   Defaults to 0.
+
+       adaptive_crop
+	   Whether or not to do a tiny bit of cropping at the borders to cut
+	   down on the amount of mirrored pixels.
+
+	   Defaults to 1.
+
+       refine_features
+	   Whether or not feature points should be refined at a sub-pixel
+	   level.
+
+	   This can be turned off for a slight performance gain at the cost of
+	   precision.
+
+	   Defaults to 1.
+
+       smooth_strength
+	   The strength of the smoothing applied to the camera path from 0.0
+	   to 1.0.
+
+	   1.0 is the maximum smoothing strength while values less than that
+	   result in less smoothing.
+
+	   0.0 causes the filter to adaptively choose a smoothing strength on
+	   a per-frame basis.
+
+	   Defaults to 0.0.
+
+       smooth_window_multiplier
+	   Controls the size of the smoothing window (the number of frames
+	   buffered to determine motion information from).
+
+	   The size of the smoothing window is determined by multiplying the
+	   framerate of the video by this number.
+
+	   Acceptable values range from 0.1 to 10.0.
+
+	   Larger values increase the amount of motion data available for
+	   determining how to smooth the camera path, potentially improving
+	   smoothness, but also increase latency and memory usage.
+
+	   Defaults to 2.0.
+
+       Examples
+
+       o   Stabilize a video with a fixed, medium smoothing strength:
+
+		   -i INPUT -vf "hwupload, deshake_opencl=smooth_strength=0.5, hwdownload" OUTPUT
+
+       o   Stabilize a video with debugging (both in console and in rendered
+	   video):
+
+		   -i INPUT -filter_complex "[0:v]format=rgba, hwupload, deshake_opencl=debug=1, hwdownload, format=rgba, format=yuv420p" -v verbose OUTPUT
+
+   dilation_opencl
+       Apply dilation effect to the video.
+
+       This filter replaces the pixel by the local(3x3) maximum.
+
+       It accepts the following options:
+
+       threshold0
+       threshold1
+       threshold2
+       threshold3
+	   Limit the maximum change for each plane. Range is "[0, 65535]" and
+	   default value is 65535.  If 0, plane will remain unchanged.
+
+       coordinates
+	   Flag which specifies the pixel to refer to.	Range is "[0, 255]"
+	   and default value is 255, i.e. all eight pixels are used.
+
+	   Flags to local 3x3 coordinates region centered on "x":
+
+	       1 2 3
+
+	       4 x 5
+
+	       6 7 8
+
+       Example
+
+       o   Apply dilation filter with threshold0 set to 30, threshold1 set 40,
+	   threshold2 set to 50 and coordinates set to 231, setting each pixel
+	   of the output to the local maximum between pixels: 1, 2, 3, 6, 7, 8
+	   of the 3x3 region centered on it in the input. If the difference
+	   between input pixel and local maximum is more then threshold of the
+	   corresponding plane, output pixel will be set to input pixel +
+	   threshold of corresponding plane.
+
+		   -i INPUT -vf "hwupload, dilation_opencl=30:40:50:coordinates=231, hwdownload" OUTPUT
+
+   nlmeans_opencl
+       Non-local Means denoise filter through OpenCL, this filter accepts same
+       options as nlmeans.
+
+   overlay_opencl
+       Overlay one video on top of another.
+
+       It takes two inputs and has one output. The first input is the "main"
+       video on which the second input is overlaid.  This filter requires same
+       memory layout for all the inputs. So, format conversion may be needed.
+
+       The filter accepts the following options:
+
+       x   Set the x coordinate of the overlaid video on the main video.
+	   Default value is 0.
+
+       y   Set the y coordinate of the overlaid video on the main video.
+	   Default value is 0.
+
+       Examples
+
+       o   Overlay an image LOGO at the top-left corner of the INPUT video.
+	   Both inputs are yuv420p format.
+
+		   -i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuv420p, hwupload[b], [a][b]overlay_opencl, hwdownload" OUTPUT
+
+       o   The inputs have same memory layout for color channels , the overlay
+	   has additional alpha plane, like INPUT is yuv420p, and the LOGO is
+	   yuva420p.
+
+		   -i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuva420p, hwupload[b], [a][b]overlay_opencl, hwdownload" OUTPUT
+
+   pad_opencl
+       Add paddings to the input image, and place the original input at the
+       provided x, y coordinates.
+
+       It accepts the following options:
+
+       width, w
+       height, h
+	   Specify an expression for the size of the output image with the
+	   paddings added. If the value for width or height is 0, the
+	   corresponding input size is used for the output.
+
+	   The width expression can reference the value set by the height
+	   expression, and vice versa.
+
+	   The default value of width and height is 0.
+
+       x
+       y   Specify the offsets to place the input image at within the padded
+	   area, with respect to the top/left border of the output image.
+
+	   The x expression can reference the value set by the y expression,
+	   and vice versa.
+
+	   The default value of x and y is 0.
+
+	   If x or y evaluate to a negative number, they'll be changed so the
+	   input image is centered on the padded area.
+
+       color
+	   Specify the color of the padded area. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+
+       aspect
+	   Pad to an aspect instead to a resolution.
+
+       The value for the width, height, x, and y options are expressions
+       containing the following constants:
+
+       in_w
+       in_h
+	   The input video width and height.
+
+       iw
+       ih  These are the same as in_w and in_h.
+
+       out_w
+       out_h
+	   The output width and height (the size of the padded area), as
+	   specified by the width and height expressions.
+
+       ow
+       oh  These are the same as out_w and out_h.
+
+       x
+       y   The x and y offsets as specified by the x and y expressions, or NAN
+	   if not yet specified.
+
+       a   same as iw / ih
+
+       sar input sample aspect ratio
+
+       dar input display aspect ratio, it is the same as (iw / ih) * sar
+
+   prewitt_opencl
+       Apply the Prewitt operator
+       (<https://en.wikipedia.org/wiki/Prewitt_operator>) to input video
+       stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes to filter. Default value is 0xf, by which all
+	   planes are processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.  Range is
+	   "[0.0, 65535]" and default value is 1.0.
+
+       delta
+	   Set value which will be added to filtered result.  Range is
+	   "[-65535, 65535]" and default value is 0.0.
+
+       Example
+
+       o   Apply the Prewitt operator with scale set to 2 and delta set to 10.
+
+		   -i INPUT -vf "hwupload, prewitt_opencl=scale=2:delta=10, hwdownload" OUTPUT
+
+   program_opencl
+       Filter video using an OpenCL program.
+
+       source
+	   OpenCL program source file.
+
+       kernel
+	   Kernel name in program.
+
+       inputs
+	   Number of inputs to the filter.  Defaults to 1.
+
+       size, s
+	   Size of output frames.  Defaults to the same as the first input.
+
+       The "program_opencl" filter also supports the framesync options.
+
+       The program source file must contain a kernel function with the given
+       name, which will be run once for each plane of the output.  Each run on
+       a plane gets enqueued as a separate 2D global NDRange with one work-
+       item for each pixel to be generated.  The global ID offset for each
+       work-item is therefore the coordinates of a pixel in the destination
+       image.
+
+       The kernel function needs to take the following arguments:
+
+       o   Destination image, __write_only image2d_t.
+
+	   This image will become the output; the kernel should write all of
+	   it.
+
+       o   Frame index, unsigned int.
+
+	   This is a counter starting from zero and increasing by one for each
+	   frame.
+
+       o   Source images, __read_only image2d_t.
+
+	   These are the most recent images on each input.  The kernel may
+	   read from them to generate the output, but they can't be written
+	   to.
+
+       Example programs:
+
+       o   Copy the input to the output (output must be the same size as the
+	   input).
+
+		   __kernel void copy(__write_only image2d_t destination,
+				      unsigned int index,
+				      __read_only  image2d_t source)
+		   {
+		       const sampler_t sampler = CLK_NORMALIZED_COORDS_FALSE;
+
+		       int2 location = (int2)(get_global_id(0), get_global_id(1));
+
+		       float4 value = read_imagef(source, sampler, location);
+
+		       write_imagef(destination, location, value);
+		   }
+
+       o   Apply a simple transformation, rotating the input by an amount
+	   increasing with the index counter.  Pixel values are linearly
+	   interpolated by the sampler, and the output need not have the same
+	   dimensions as the input.
+
+		   __kernel void rotate_image(__write_only image2d_t dst,
+					      unsigned int index,
+					      __read_only  image2d_t src)
+		   {
+		       const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
+						  CLK_FILTER_LINEAR);
+
+		       float angle = (float)index / 100.0f;
+
+		       float2 dst_dim = convert_float2(get_image_dim(dst));
+		       float2 src_dim = convert_float2(get_image_dim(src));
+
+		       float2 dst_cen = dst_dim / 2.0f;
+		       float2 src_cen = src_dim / 2.0f;
+
+		       int2   dst_loc = (int2)(get_global_id(0), get_global_id(1));
+
+		       float2 dst_pos = convert_float2(dst_loc) - dst_cen;
+		       float2 src_pos = {
+			   cos(angle) * dst_pos.x - sin(angle) * dst_pos.y,
+			   sin(angle) * dst_pos.x + cos(angle) * dst_pos.y
+		       };
+		       src_pos = src_pos * src_dim / dst_dim;
+
+		       float2 src_loc = src_pos + src_cen;
+
+		       if (src_loc.x < 0.0f	 || src_loc.y < 0.0f ||
+			   src_loc.x > src_dim.x || src_loc.y > src_dim.y)
+			   write_imagef(dst, dst_loc, 0.5f);
+		       else
+			   write_imagef(dst, dst_loc, read_imagef(src, sampler, src_loc));
+		   }
+
+       o   Blend two inputs together, with the amount of each input used
+	   varying with the index counter.
+
+		   __kernel void blend_images(__write_only image2d_t dst,
+					      unsigned int index,
+					      __read_only  image2d_t src1,
+					      __read_only  image2d_t src2)
+		   {
+		       const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
+						  CLK_FILTER_LINEAR);
+
+		       float blend = (cos((float)index / 50.0f) + 1.0f) / 2.0f;
+
+		       int2  dst_loc = (int2)(get_global_id(0), get_global_id(1));
+		       int2 src1_loc = dst_loc * get_image_dim(src1) / get_image_dim(dst);
+		       int2 src2_loc = dst_loc * get_image_dim(src2) / get_image_dim(dst);
+
+		       float4 val1 = read_imagef(src1, sampler, src1_loc);
+		       float4 val2 = read_imagef(src2, sampler, src2_loc);
+
+		       write_imagef(dst, dst_loc, val1 * blend + val2 * (1.0f - blend));
+		   }
+
+   remap_opencl
+       Remap pixels using 2nd: Xmap and 3rd: Ymap input video stream.
+
+       Destination pixel at position (X, Y) will be picked from source (x, y)
+       position where x = Xmap(X, Y) and y = Ymap(X, Y). If mapping values are
+       out of range, zero value for pixel will be used for destination pixel.
+
+       Xmap and Ymap input video streams must be of same dimensions. Output
+       video stream will have Xmap/Ymap video stream dimensions.  Xmap and
+       Ymap input video streams are 32bit float pixel format, single channel.
+
+       interp
+	   Specify interpolation used for remapping of pixels.	Allowed values
+	   are "near" and "linear".  Default value is "linear".
+
+       fill
+	   Specify the color of the unmapped pixels. For the syntax of this
+	   option, check the "Color" section in the ffmpeg-utils manual.
+	   Default color is "black".
+
+   roberts_opencl
+       Apply the Roberts cross operator
+       (<https://en.wikipedia.org/wiki/Roberts_cross>) to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes to filter. Default value is 0xf, by which all
+	   planes are processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.  Range is
+	   "[0.0, 65535]" and default value is 1.0.
+
+       delta
+	   Set value which will be added to filtered result.  Range is
+	   "[-65535, 65535]" and default value is 0.0.
+
+       Example
+
+       o   Apply the Roberts cross operator with scale set to 2 and delta set
+	   to 10
+
+		   -i INPUT -vf "hwupload, roberts_opencl=scale=2:delta=10, hwdownload" OUTPUT
+
+   sobel_opencl
+       Apply the Sobel operator
+       (<https://en.wikipedia.org/wiki/Sobel_operator>) to input video stream.
+
+       The filter accepts the following option:
+
+       planes
+	   Set which planes to filter. Default value is 0xf, by which all
+	   planes are processed.
+
+       scale
+	   Set value which will be multiplied with filtered result.  Range is
+	   "[0.0, 65535]" and default value is 1.0.
+
+       delta
+	   Set value which will be added to filtered result.  Range is
+	   "[-65535, 65535]" and default value is 0.0.
+
+       Example
+
+       o   Apply sobel operator with scale set to 2 and delta set to 10
+
+		   -i INPUT -vf "hwupload, sobel_opencl=scale=2:delta=10, hwdownload" OUTPUT
+
+   tonemap_opencl
+       Perform HDR(PQ/HLG) to SDR conversion with tone-mapping.
+
+       It accepts the following parameters:
+
+       tonemap
+	   Specify the tone-mapping operator to be used. Same as tonemap
+	   option in tonemap.
+
+       param
+	   Tune the tone mapping algorithm. same as param option in tonemap.
+
+       desat
+	   Apply desaturation for highlights that exceed this level of
+	   brightness. The higher the parameter, the more color information
+	   will be preserved. This setting helps prevent unnaturally blown-out
+	   colors for super-highlights, by (smoothly) turning into white
+	   instead. This makes images feel more natural, at the cost of
+	   reducing information about out-of-range colors.
+
+	   The default value is 0.5, and the algorithm here is a little
+	   different from the cpu version tonemap currently. A setting of 0.0
+	   disables this option.
+
+       threshold
+	   The tonemapping algorithm parameters is fine-tuned per each scene.
+	   And a threshold is used to detect whether the scene has changed or
+	   not. If the distance between the current frame average brightness
+	   and the current running average exceeds a threshold value, we would
+	   re-calculate scene average and peak brightness.  The default value
+	   is 0.2.
+
+       format
+	   Specify the output pixel format.
+
+	   Currently supported formats are:
+
+	   p010
+	   nv12
+       range, r
+	   Set the output color range.
+
+	   Possible values are:
+
+	   tv/mpeg
+	   pc/jpeg
+
+	   Default is same as input.
+
+       primaries, p
+	   Set the output color primaries.
+
+	   Possible values are:
+
+	   bt709
+	   bt2020
+
+	   Default is same as input.
+
+       transfer, t
+	   Set the output transfer characteristics.
+
+	   Possible values are:
+
+	   bt709
+	   bt2020
+
+	   Default is bt709.
+
+       matrix, m
+	   Set the output colorspace matrix.
+
+	   Possible value are:
+
+	   bt709
+	   bt2020
+
+	   Default is same as input.
+
+       Example
+
+       o   Convert HDR(PQ/HLG) video to bt2020-transfer-characteristic p010
+	   format using linear operator.
+
+		   -i INPUT -vf "format=p010,hwupload,tonemap_opencl=t=bt2020:tonemap=linear:format=p010,hwdownload,format=p010" OUTPUT
+
+   unsharp_opencl
+       Sharpen or blur the input video.
+
+       It accepts the following parameters:
+
+       luma_msize_x, lx
+	   Set the luma matrix horizontal size.  Range is "[1, 23]" and
+	   default value is 5.
+
+       luma_msize_y, ly
+	   Set the luma matrix vertical size.  Range is "[1, 23]" and default
+	   value is 5.
+
+       luma_amount, la
+	   Set the luma effect strength.  Range is "[-10, 10]" and default
+	   value is 1.0.
+
+	   Negative values will blur the input video, while positive values
+	   will sharpen it, a value of zero will disable the effect.
+
+       chroma_msize_x, cx
+	   Set the chroma matrix horizontal size.  Range is "[1, 23]" and
+	   default value is 5.
+
+       chroma_msize_y, cy
+	   Set the chroma matrix vertical size.  Range is "[1, 23]" and
+	   default value is 5.
+
+       chroma_amount, ca
+	   Set the chroma effect strength.  Range is "[-10, 10]" and default
+	   value is 0.0.
+
+	   Negative values will blur the input video, while positive values
+	   will sharpen it, a value of zero will disable the effect.
+
+       All parameters are optional and default to the equivalent of the string
+       '5:5:1.0:5:5:0.0'.
+
+       Examples
+
+       o   Apply strong luma sharpen effect:
+
+		   -i INPUT -vf "hwupload, unsharp_opencl=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5, hwdownload" OUTPUT
+
+       o   Apply a strong blur of both luma and chroma parameters:
+
+		   -i INPUT -vf "hwupload, unsharp_opencl=7:7:-2:7:7:-2, hwdownload" OUTPUT
+
+   xfade_opencl
+       Cross fade two videos with custom transition effect by using OpenCL.
+
+       It accepts the following options:
+
+       transition
+	   Set one of possible transition effects.
+
+	   custom
+	       Select custom transition effect, the actual transition
+	       description will be picked from source and kernel options.
+
+	   fade
+	   wipeleft
+	   wiperight
+	   wipeup
+	   wipedown
+	   slideleft
+	   slideright
+	   slideup
+	   slidedown
+	       Default transition is fade.
+
+       source
+	   OpenCL program source file for custom transition.
+
+       kernel
+	   Set name of kernel to use for custom transition from program source
+	   file.
+
+       duration
+	   Set duration of video transition.
+
+       offset
+	   Set time of start of transition relative to first video.
+
+       The program source file must contain a kernel function with the given
+       name, which will be run once for each plane of the output.  Each run on
+       a plane gets enqueued as a separate 2D global NDRange with one work-
+       item for each pixel to be generated.  The global ID offset for each
+       work-item is therefore the coordinates of a pixel in the destination
+       image.
+
+       The kernel function needs to take the following arguments:
+
+       o   Destination image, __write_only image2d_t.
+
+	   This image will become the output; the kernel should write all of
+	   it.
+
+       o   First Source image, __read_only image2d_t.  Second Source image,
+	   __read_only image2d_t.
+
+	   These are the most recent images on each input.  The kernel may
+	   read from them to generate the output, but they can't be written
+	   to.
+
+       o   Transition progress, float. This value is always between 0 and 1
+	   inclusive.
+
+       Example programs:
+
+       o   Apply dots curtain transition effect:
+
+		   __kernel void blend_images(__write_only image2d_t dst,
+					      __read_only  image2d_t src1,
+					      __read_only  image2d_t src2,
+					      float progress)
+		   {
+		       const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
+						  CLK_FILTER_LINEAR);
+		       int2  p = (int2)(get_global_id(0), get_global_id(1));
+		       float2 rp = (float2)(get_global_id(0), get_global_id(1));
+		       float2 dim = (float2)(get_image_dim(src1).x, get_image_dim(src1).y);
+		       rp = rp / dim;
+
+		       float2 dots = (float2)(20.0, 20.0);
+		       float2 center = (float2)(0,0);
+		       float2 unused;
+
+		       float4 val1 = read_imagef(src1, sampler, p);
+		       float4 val2 = read_imagef(src2, sampler, p);
+		       bool next = distance(fract(rp * dots, &unused), (float2)(0.5, 0.5)) < (progress / distance(rp, center));
+
+		       write_imagef(dst, p, next ? val1 : val2);
+		   }
+
+VAAPI VIDEO FILTERS
+       VAAPI Video filters are usually used with VAAPI decoder and VAAPI
+       encoder. Below is a description of VAAPI video filters.
+
+       To enable compilation of these filters you need to configure FFmpeg
+       with "--enable-vaapi".
+
+       To use vaapi filters, you need to setup the vaapi device correctly. For
+       more information, please read
+       <https://trac.ffmpeg.org/wiki/Hardware/VAAPI>
+
+   overlay_vaapi
+       Overlay one video on the top of another.
+
+       It takes two inputs and has one output. The first input is the "main"
+       video on which the second input is overlaid.
+
+       The filter accepts the following options:
+
+       x
+       y   Set expressions for the x and y coordinates of the overlaid video
+	   on the main video.
+
+	   Default value is "0" for both expressions.
+
+       w
+       h   Set expressions for the width and height the overlaid video on the
+	   main video.
+
+	   Default values are 'overlay_iw' for 'w' and
+	   'overlay_ih*w/overlay_iw' for 'h'.
+
+	   The expressions can contain the following parameters:
+
+	   main_w, W
+	   main_h, H
+	       The main input width and height.
+
+	   overlay_iw
+	   overlay_ih
+	       The overlay input width and height.
+
+	   overlay_w, w
+	   overlay_h, h
+	       The overlay output width and height.
+
+	   overlay_x, x
+	   overlay_y, y
+	       Position of the overlay layer inside of main
+
+       alpha
+	   Set transparency of overlaid video. Allowed range is 0.0 to 1.0.
+	   Higher value means lower transparency.  Default value is 1.0.
+
+       eof_action
+	   See framesync.
+
+       shortest
+	   See framesync.
+
+       repeatlast
+	   See framesync.
+
+       This filter also supports the framesync options.
+
+       Examples
+
+       o   Overlay an image LOGO at the top-left corner of the INPUT video.
+	   Both inputs for this filter are yuv420p format.
+
+		   -i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuv420p, hwupload[b], [a][b]overlay_vaapi" OUTPUT
+
+       o   Overlay an image LOGO at the offset (200, 100) from the top-left
+	   corner of the INPUT video.  The inputs have same memory layout for
+	   color channels, the overlay has additional alpha plane, like INPUT
+	   is yuv420p, and the LOGO is yuva420p.
+
+		   -i INPUT -i LOGO -filter_complex "[0:v]hwupload[a], [1:v]format=yuva420p, hwupload[b], [a][b]overlay_vaapi=x=200:y=100:w=400:h=300:alpha=1.0, hwdownload, format=nv12" OUTPUT
+
+   tonemap_vaapi
+       Perform HDR(High Dynamic Range) to SDR(Standard Dynamic Range)
+       conversion with tone-mapping.  It maps the dynamic range of HDR10
+       content to the SDR content.  It currently only accepts HDR10 as input.
+
+       It accepts the following parameters:
+
+       format
+	   Specify the output pixel format.
+
+	   Currently supported formats are:
+
+	   p010
+	   nv12
+
+	   Default is nv12.
+
+       primaries, p
+	   Set the output color primaries.
+
+	   Default is same as input.
+
+       transfer, t
+	   Set the output transfer characteristics.
+
+	   Default is bt709.
+
+       matrix, m
+	   Set the output colorspace matrix.
+
+	   Default is same as input.
+
+       Example
+
+       o   Convert HDR(HDR10) video to bt2020-transfer-characteristic p010
+	   format
+
+		   tonemap_vaapi=format=p010:t=bt2020-10
+
+   hstack_vaapi
+       Stack input videos horizontally.
+
+       This is the VA-API variant of the hstack filter, each input stream may
+       have different height, this filter will scale down/up each input stream
+       while keeping the orignal aspect.
+
+       It accepts the following options:
+
+       inputs
+	   See hstack.
+
+       shortest
+	   See hstack.
+
+       height
+	   Set height of output. If set to 0, this filter will set height of
+	   output to height of the first input stream. Default value is 0.
+
+   vstack_vaapi
+       Stack input videos vertically.
+
+       This is the VA-API variant of the vstack filter, each input stream may
+       have different width, this filter will scale down/up each input stream
+       while keeping the orignal aspect.
+
+       It accepts the following options:
+
+       inputs
+	   See vstack.
+
+       shortest
+	   See vstack.
+
+       width
+	   Set width of output. If set to 0, this filter will set width of
+	   output to width of the first input stream. Default value is 0.
+
+   xstack_vaapi
+       Stack video inputs into custom layout.
+
+       This is the VA-API variant of the xstack filter,  each input stream may
+       have different size, this filter will scale down/up each input stream
+       to the given output size, or the size of the first input stream.
+
+       It accepts the following options:
+
+       inputs
+	   See xstack.
+
+       shortest
+	   See xstack.
+
+       layout
+	   See xstack.	Moreover, this permits the user to supply output size
+	   for each input stream.
+
+		   xstack_vaapi=inputs=4:layout=0_0_1920x1080|0_h0_1920x1080|w0_0_1920x1080|w0_h0_1920x1080
+
+       grid
+	   See xstack.
+
+       grid_tile_size
+	   Set output size for each input stream when grid is set. If this
+	   option is not set, this filter will set output size by default to
+	   the size of the first input stream. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.
+
+       fill
+	   See xstack.
+
+QSV VIDEO FILTERS
+       Below is a description of the currently available QSV video filters.
+
+       To enable compilation of these filters you need to configure FFmpeg
+       with "--enable-libmfx" or "--enable-libvpl".
+
+       To use QSV filters, you need to setup the QSV device correctly. For
+       more information, please read
+       <https://trac.ffmpeg.org/wiki/Hardware/QuickSync>
+
+   hstack_qsv
+       Stack input videos horizontally.
+
+       This is the QSV variant of the hstack filter, each input stream may
+       have different height, this filter will scale down/up each input stream
+       while keeping the orignal aspect.
+
+       It accepts the following options:
+
+       inputs
+	   See hstack.
+
+       shortest
+	   See hstack.
+
+       height
+	   Set height of output. If set to 0, this filter will set height of
+	   output to height of the first input stream. Default value is 0.
+
+   vstack_qsv
+       Stack input videos vertically.
+
+       This is the QSV variant of the vstack filter, each input stream may
+       have different width, this filter will scale down/up each input stream
+       while keeping the orignal aspect.
+
+       It accepts the following options:
+
+       inputs
+	   See vstack.
+
+       shortest
+	   See vstack.
+
+       width
+	   Set width of output. If set to 0, this filter will set width of
+	   output to width of the first input stream. Default value is 0.
+
+   xstack_qsv
+       Stack video inputs into custom layout.
+
+       This is the QSV variant of the xstack filter.
+
+       It accepts the following options:
+
+       inputs
+	   See xstack.
+
+       shortest
+	   See xstack.
+
+       layout
+	   See xstack.	Moreover, this permits the user to supply output size
+	   for each input stream.
+
+		   xstack_qsv=inputs=4:layout=0_0_1920x1080|0_h0_1920x1080|w0_0_1920x1080|w0_h0_1920x1080
+
+       grid
+	   See xstack.
+
+       grid_tile_size
+	   Set output size for each input stream when grid is set. If this
+	   option is not set, this filter will set output size by default to
+	   the size of the first input stream. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.
+
+       fill
+	   See xstack.
+
+VIDEO SOURCES
+       Below is a description of the currently available video sources.
+
+   buffer
+       Buffer video frames, and make them available to the filter chain.
+
+       This source is mainly intended for a programmatic use, in particular
+       through the interface defined in libavfilter/buffersrc.h.
+
+       It accepts the following parameters:
+
+       video_size
+	   Specify the size (width and height) of the buffered video frames.
+	   For the syntax of this option, check the "Video size" section in
+	   the ffmpeg-utils manual.
+
+       width
+	   The input video width.
+
+       height
+	   The input video height.
+
+       pix_fmt
+	   A string representing the pixel format of the buffered video
+	   frames.  It may be a number corresponding to a pixel format, or a
+	   pixel format name.
+
+       time_base
+	   Specify the timebase assumed by the timestamps of the buffered
+	   frames.
+
+       frame_rate
+	   Specify the frame rate expected for the video stream.
+
+       pixel_aspect, sar
+	   The sample (pixel) aspect ratio of the input video.
+
+       hw_frames_ctx
+	   When using a hardware pixel format, this should be a reference to
+	   an AVHWFramesContext describing input frames.
+
+       For example:
+
+	       buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
+
+       will instruct the source to accept video frames with size 320x240 and
+       with format "yuv410p", assuming 1/24 as the timestamps timebase and
+       square pixels (1:1 sample aspect ratio).  Since the pixel format with
+       name "yuv410p" corresponds to the number 6 (check the enum
+       AVPixelFormat definition in libavutil/pixfmt.h), this example
+       corresponds to:
+
+	       buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
+
+       Alternatively, the options can be specified as a flat string, but this
+       syntax is deprecated:
+
+       width:height:pix_fmt:time_base.num:time_base.den:pixel_aspect.num:pixel_aspect.den
+
+   cellauto
+       Create a pattern generated by an elementary cellular automaton.
+
+       The initial state of the cellular automaton can be defined through the
+       filename and pattern options. If such options are not specified an
+       initial state is created randomly.
+
+       At each new frame a new row in the video is filled with the result of
+       the cellular automaton next generation. The behavior when the whole
+       frame is filled is defined by the scroll option.
+
+       This source accepts the following options:
+
+       filename, f
+	   Read the initial cellular automaton state, i.e. the starting row,
+	   from the specified file.  In the file, each non-whitespace
+	   character is considered an alive cell, a newline will terminate the
+	   row, and further characters in the file will be ignored.
+
+       pattern, p
+	   Read the initial cellular automaton state, i.e. the starting row,
+	   from the specified string.
+
+	   Each non-whitespace character in the string is considered an alive
+	   cell, a newline will terminate the row, and further characters in
+	   the string will be ignored.
+
+       rate, r
+	   Set the video rate, that is the number of frames generated per
+	   second.  Default is 25.
+
+       random_fill_ratio, ratio
+	   Set the random fill ratio for the initial cellular automaton row.
+	   It is a floating point number value ranging from 0 to 1, defaults
+	   to 1/PHI.
+
+	   This option is ignored when a file or a pattern is specified.
+
+       random_seed, seed
+	   Set the seed for filling randomly the initial row, must be an
+	   integer included between 0 and UINT32_MAX. If not specified, or if
+	   explicitly set to -1, the filter will try to use a good random seed
+	   on a best effort basis.
+
+       rule
+	   Set the cellular automaton rule, it is a number ranging from 0 to
+	   255.  Default value is 110.
+
+       size, s
+	   Set the size of the output video. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.
+
+	   If filename or pattern is specified, the size is set by default to
+	   the width of the specified initial state row, and the height is set
+	   to width * PHI.
+
+	   If size is set, it must contain the width of the specified pattern
+	   string, and the specified pattern will be centered in the larger
+	   row.
+
+	   If a filename or a pattern string is not specified, the size value
+	   defaults to "320x518" (used for a randomly generated initial
+	   state).
+
+       scroll
+	   If set to 1, scroll the output upward when all the rows in the
+	   output have been already filled. If set to 0, the new generated row
+	   will be written over the top row just after the bottom row is
+	   filled.  Defaults to 1.
+
+       start_full, full
+	   If set to 1, completely fill the output with generated rows before
+	   outputting the first frame.	This is the default behavior, for
+	   disabling set the value to 0.
+
+       stitch
+	   If set to 1, stitch the left and right row edges together.  This is
+	   the default behavior, for disabling set the value to 0.
+
+       Examples
+
+       o   Read the initial state from pattern, and specify an output of size
+	   200x400.
+
+		   cellauto=f=pattern:s=200x400
+
+       o   Generate a random initial row with a width of 200 cells, with a
+	   fill ratio of 2/3:
+
+		   cellauto=ratio=2/3:s=200x200
+
+       o   Create a pattern generated by rule 18 starting by a single alive
+	   cell centered on an initial row with width 100:
+
+		   cellauto=p=@s=100x400:full=0:rule=18
+
+       o   Specify a more elaborated initial pattern:
+
+		   cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
+
+   coreimagesrc
+       Video source generated on GPU using Apple's CoreImage API on OSX.
+
+       This video source is a specialized version of the coreimage video
+       filter.	Use a core image generator at the beginning of the applied
+       filterchain to generate the content.
+
+       The coreimagesrc video source accepts the following options:
+
+       list_generators
+	   List all available generators along with all their respective
+	   options as well as possible minimum and maximum values along with
+	   the default values.
+
+		   list_generators=true
+
+       size, s
+	   Specify the size of the sourced video. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   The default value is "320x240".
+
+       rate, r
+	   Specify the frame rate of the sourced video, as the number of
+	   frames generated per second. It has to be a string in the format
+	   frame_rate_num/frame_rate_den, an integer number, a floating point
+	   number or a valid video frame rate abbreviation. The default value
+	   is "25".
+
+       sar Set the sample aspect ratio of the sourced video.
+
+       duration, d
+	   Set the duration of the sourced video. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.
+
+	   If not specified, or the expressed duration is negative, the video
+	   is supposed to be generated forever.
+
+       Additionally, all options of the coreimage video filter are accepted.
+       A complete filterchain can be used for further processing of the
+       generated input without CPU-HOST transfer. See coreimage documentation
+       and examples for details.
+
+       Examples
+
+       o   Use CIQRCodeGenerator to create a QR code for the FFmpeg homepage,
+	   given as complete and escaped command-line for Apple's standard
+	   bash shell:
+
+		   ffmpeg -f lavfi -i coreimagesrc=s=100x100:filter=CIQRCodeGenerator@inputMessage=https\\\\\://FFmpeg.org/@inputCorrectionLevel=H -frames:v 1 QRCode.png
+
+	   This example is equivalent to the QRCode example of coreimage
+	   without the need for a nullsrc video source.
+
+   ddagrab
+       Captures the Windows Desktop via Desktop Duplication API.
+
+       The filter exclusively returns D3D11 Hardware Frames, for on-gpu
+       encoding or processing. So an explicit hwdownload is needed for any
+       kind of software processing.
+
+       It accepts the following options:
+
+       output_idx
+	   DXGI Output Index to capture.
+
+	   Usually corresponds to the index Windows has given the screen minus
+	   one, so it's starting at 0.
+
+	   Defaults to output 0.
+
+       draw_mouse
+	   Whether to draw the mouse cursor.
+
+	   Defaults to true.
+
+	   Only affects hardware cursors. If a game or application renders its
+	   own cursor, it'll always be captured.
+
+       framerate
+	   Framerate at which the desktop will be captured.
+
+	   Defaults to 30 FPS.
+
+       video_size
+	   Specify the size of the captured video.
+
+	   Defaults to the full size of the screen.
+
+	   Cropped from the bottom/right if smaller than screen size.
+
+       offset_x
+	   Horizontal offset of the captured video.
+
+       offset_y
+	   Vertical offset of the captured video.
+
+       output_fmt
+	   Desired filter output format.  Defaults to 8 Bit BGRA.
+
+	   It accepts the following values:
+
+	   auto
+	       Passes all supported output formats to DDA and returns what DDA
+	       decides to use.
+
+	   8bit
+	   bgra
+	       8 Bit formats always work, and DDA will convert to them if
+	       neccesary.
+
+	   10bit
+	   x2bgr10
+	       Filter initialization will fail if 10 bit format is requested
+	       but unavailable.
+
+       Examples
+
+       Capture primary screen and encode using nvenc:
+
+	       ffmpeg -f lavfi -i ddagrab -c:v h264_nvenc -cq 18 output.mp4
+
+       You can also skip the lavfi device and directly use the filter.	Also
+       demonstrates downloading the frame and encoding with libx264.  Explicit
+       output format specification is required in this case:
+
+	       ffmpeg -filter_complex ddagrab=output_idx=1:framerate=60,hwdownload,format=bgra -c:v libx264 -crf 18 output.mp4
+
+       If you want to capture only a subsection of the desktop, this can be
+       achieved by specifying a smaller size and its offsets into the screen:
+
+	       ddagrab=video_size=800x600:offset_x=100:offset_y=100
+
+   gradients
+       Generate several gradients.
+
+       size, s
+	   Set frame size. For the syntax of this option, check the "Video
+	   size" section in the ffmpeg-utils manual. Default value is
+	   "640x480".
+
+       rate, r
+	   Set frame rate, expressed as number of frames per second. Default
+	   value is "25".
+
+       c0, c1, c2, c3, c4, c5, c6, c7
+	   Set 8 colors. Default values for colors is to pick random one.
+
+       x0, y0, y0, y1
+	   Set gradient line source and destination points. If negative or out
+	   of range, random ones are picked.
+
+       nb_colors, n
+	   Set number of colors to use at once. Allowed range is from 2 to 8.
+	   Default value is 2.
+
+       seed
+	   Set seed for picking gradient line points.
+
+       duration, d
+	   Set the duration of the sourced video. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.
+
+	   If not specified, or the expressed duration is negative, the video
+	   is supposed to be generated forever.
+
+       speed
+	   Set speed of gradients rotation.
+
+       type, t
+	   Set type of gradients, can be "linear" or "radial" or "circular" or
+	   "spiral".
+
+   mandelbrot
+       Generate a Mandelbrot set fractal, and progressively zoom towards the
+       point specified with start_x and start_y.
+
+       This source accepts the following options:
+
+       end_pts
+	   Set the terminal pts value. Default value is 400.
+
+       end_scale
+	   Set the terminal scale value.  Must be a floating point value.
+	   Default value is 0.3.
+
+       inner
+	   Set the inner coloring mode, that is the algorithm used to draw the
+	   Mandelbrot fractal internal region.
+
+	   It shall assume one of the following values:
+
+	   black
+	       Set black mode.
+
+	   convergence
+	       Show time until convergence.
+
+	   mincol
+	       Set color based on point closest to the origin of the
+	       iterations.
+
+	   period
+	       Set period mode.
+
+	   Default value is mincol.
+
+       bailout
+	   Set the bailout value. Default value is 10.0.
+
+       maxiter
+	   Set the maximum of iterations performed by the rendering algorithm.
+	   Default value is 7189.
+
+       outer
+	   Set outer coloring mode.  It shall assume one of following values:
+
+	   iteration_count
+	       Set iteration count mode.
+
+	   normalized_iteration_count
+	       set normalized iteration count mode.
+
+	   Default value is normalized_iteration_count.
+
+       rate, r
+	   Set frame rate, expressed as number of frames per second. Default
+	   value is "25".
+
+       size, s
+	   Set frame size. For the syntax of this option, check the "Video
+	   size" section in the ffmpeg-utils manual. Default value is
+	   "640x480".
+
+       start_scale
+	   Set the initial scale value. Default value is 3.0.
+
+       start_x
+	   Set the initial x position. Must be a floating point value between
+	   -100 and 100. Default value is
+	   -0.743643887037158704752191506114774.
+
+       start_y
+	   Set the initial y position. Must be a floating point value between
+	   -100 and 100. Default value is
+	   -0.131825904205311970493132056385139.
+
+   mptestsrc
+       Generate various test patterns, as generated by the MPlayer test
+       filter.
+
+       The size of the generated video is fixed, and is 256x256.  This source
+       is useful in particular for testing encoding features.
+
+       This source accepts the following options:
+
+       rate, r
+	   Specify the frame rate of the sourced video, as the number of
+	   frames generated per second. It has to be a string in the format
+	   frame_rate_num/frame_rate_den, an integer number, a floating point
+	   number or a valid video frame rate abbreviation. The default value
+	   is "25".
+
+       duration, d
+	   Set the duration of the sourced video. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.
+
+	   If not specified, or the expressed duration is negative, the video
+	   is supposed to be generated forever.
+
+       test, t
+	   Set the number or the name of the test to perform. Supported tests
+	   are:
+
+	   dc_luma
+	   dc_chroma
+	   freq_luma
+	   freq_chroma
+	   amp_luma
+	   amp_chroma
+	   cbp
+	   mv
+	   ring1
+	   ring2
+	   all
+	   max_frames, m
+	       Set the maximum number of frames generated for each test,
+	       default value is 30.
+
+	   Default value is "all", which will cycle through the list of all
+	   tests.
+
+       Some examples:
+
+	       mptestsrc=t=dc_luma
+
+       will generate a "dc_luma" test pattern.
+
+   frei0r_src
+       Provide a frei0r source.
+
+       To enable compilation of this filter you need to install the frei0r
+       header and configure FFmpeg with "--enable-frei0r".
+
+       This source accepts the following parameters:
+
+       size
+	   The size of the video to generate. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.
+
+       framerate
+	   The framerate of the generated video. It may be a string of the
+	   form num/den or a frame rate abbreviation.
+
+       filter_name
+	   The name to the frei0r source to load. For more information
+	   regarding frei0r and how to set the parameters, read the frei0r
+	   section in the video filters documentation.
+
+       filter_params
+	   A '|'-separated list of parameters to pass to the frei0r source.
+
+       For example, to generate a frei0r partik0l source with size 200x200 and
+       frame rate 10 which is overlaid on the overlay filter main input:
+
+	       frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
+
+   life
+       Generate a life pattern.
+
+       This source is based on a generalization of John Conway's life game.
+
+       The sourced input represents a life grid, each pixel represents a cell
+       which can be in one of two possible states, alive or dead. Every cell
+       interacts with its eight neighbours, which are the cells that are
+       horizontally, vertically, or diagonally adjacent.
+
+       At each interaction the grid evolves according to the adopted rule,
+       which specifies the number of neighbor alive cells which will make a
+       cell stay alive or born. The rule option allows one to specify the rule
+       to adopt.
+
+       This source accepts the following options:
+
+       filename, f
+	   Set the file from which to read the initial grid state. In the
+	   file, each non-whitespace character is considered an alive cell,
+	   and newline is used to delimit the end of each row.
+
+	   If this option is not specified, the initial grid is generated
+	   randomly.
+
+       rate, r
+	   Set the video rate, that is the number of frames generated per
+	   second.  Default is 25.
+
+       random_fill_ratio, ratio
+	   Set the random fill ratio for the initial random grid. It is a
+	   floating point number value ranging from 0 to 1, defaults to 1/PHI.
+	   It is ignored when a file is specified.
+
+       random_seed, seed
+	   Set the seed for filling the initial random grid, must be an
+	   integer included between 0 and UINT32_MAX. If not specified, or if
+	   explicitly set to -1, the filter will try to use a good random seed
+	   on a best effort basis.
+
+       rule
+	   Set the life rule.
+
+	   A rule can be specified with a code of the kind "SNS/BNB", where NS
+	   and NB are sequences of numbers in the range 0-8, NS specifies the
+	   number of alive neighbor cells which make a live cell stay alive,
+	   and NB the number of alive neighbor cells which make a dead cell to
+	   become alive (i.e. to "born").  "s" and "b" can be used in place of
+	   "S" and "B", respectively.
+
+	   Alternatively a rule can be specified by an 18-bits integer. The 9
+	   high order bits are used to encode the next cell state if it is
+	   alive for each number of neighbor alive cells, the low order bits
+	   specify the rule for "borning" new cells. Higher order bits encode
+	   for an higher number of neighbor cells.  For example the number
+	   6153 = "(12<<9)+9" specifies a stay alive rule of 12 and a born
+	   rule of 9, which corresponds to "S23/B03".
+
+	   Default value is "S23/B3", which is the original Conway's game of
+	   life rule, and will keep a cell alive if it has 2 or 3 neighbor
+	   alive cells, and will born a new cell if there are three alive
+	   cells around a dead cell.
+
+       size, s
+	   Set the size of the output video. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.
+
+	   If filename is specified, the size is set by default to the same
+	   size of the input file. If size is set, it must contain the size
+	   specified in the input file, and the initial grid defined in that
+	   file is centered in the larger resulting area.
+
+	   If a filename is not specified, the size value defaults to
+	   "320x240" (used for a randomly generated initial grid).
+
+       stitch
+	   If set to 1, stitch the left and right grid edges together, and the
+	   top and bottom edges also. Defaults to 1.
+
+       mold
+	   Set cell mold speed. If set, a dead cell will go from death_color
+	   to mold_color with a step of mold. mold can have a value from 0 to
+	   255.
+
+       life_color
+	   Set the color of living (or new born) cells.
+
+       death_color
+	   Set the color of dead cells. If mold is set, this is the first
+	   color used to represent a dead cell.
+
+       mold_color
+	   Set mold color, for definitely dead and moldy cells.
+
+	   For the syntax of these 3 color options, check the "Color" section
+	   in the ffmpeg-utils manual.
+
+       Examples
+
+       o   Read a grid from pattern, and center it on a grid of size 300x300
+	   pixels:
+
+		   life=f=pattern:s=300x300
+
+       o   Generate a random grid of size 200x200, with a fill ratio of 2/3:
+
+		   life=ratio=2/3:s=200x200
+
+       o   Specify a custom rule for evolving a randomly generated grid:
+
+		   life=rule=S14/B34
+
+       o   Full example with slow death effect (mold) using ffplay:
+
+		   ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
+
+   allrgb, allyuv, color, colorchart, colorspectrum, haldclutsrc, nullsrc,
+       pal75bars, pal100bars, rgbtestsrc, smptebars, smptehdbars, testsrc,
+       testsrc2, yuvtestsrc
+       The "allrgb" source returns frames of size 4096x4096 of all rgb colors.
+
+       The "allyuv" source returns frames of size 4096x4096 of all yuv colors.
+
+       The "color" source provides an uniformly colored input.
+
+       The "colorchart" source provides a colors checker chart.
+
+       The "colorspectrum" source provides a color spectrum input.
+
+       The "haldclutsrc" source provides an identity Hald CLUT. See also
+       haldclut filter.
+
+       The "nullsrc" source returns unprocessed video frames. It is mainly
+       useful to be employed in analysis / debugging tools, or as the source
+       for filters which ignore the input data.
+
+       The "pal75bars" source generates a color bars pattern, based on EBU PAL
+       recommendations with 75% color levels.
+
+       The "pal100bars" source generates a color bars pattern, based on EBU
+       PAL recommendations with 100% color levels.
+
+       The "rgbtestsrc" source generates an RGB test pattern useful for
+       detecting RGB vs BGR issues. You should see a red, green and blue
+       stripe from top to bottom.
+
+       The "smptebars" source generates a color bars pattern, based on the
+       SMPTE Engineering Guideline EG 1-1990.
+
+       The "smptehdbars" source generates a color bars pattern, based on the
+       SMPTE RP 219-2002.
+
+       The "testsrc" source generates a test video pattern, showing a color
+       pattern, a scrolling gradient and a timestamp. This is mainly intended
+       for testing purposes.
+
+       The "testsrc2" source is similar to testsrc, but supports more pixel
+       formats instead of just "rgb24". This allows using it as an input for
+       other tests without requiring a format conversion.
+
+       The "yuvtestsrc" source generates an YUV test pattern. You should see a
+       y, cb and cr stripe from top to bottom.
+
+       The sources accept the following parameters:
+
+       level
+	   Specify the level of the Hald CLUT, only available in the
+	   "haldclutsrc" source. A level of "N" generates a picture of "N*N*N"
+	   by "N*N*N" pixels to be used as identity matrix for 3D lookup
+	   tables. Each component is coded on a "1/(N*N)" scale.
+
+       color, c
+	   Specify the color of the source, only available in the "color"
+	   source. For the syntax of this option, check the "Color" section in
+	   the ffmpeg-utils manual.
+
+       size, s
+	   Specify the size of the sourced video. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   The default value is "320x240".
+
+	   This option is not available with the "allrgb", "allyuv", and
+	   "haldclutsrc" filters.
+
+       rate, r
+	   Specify the frame rate of the sourced video, as the number of
+	   frames generated per second. It has to be a string in the format
+	   frame_rate_num/frame_rate_den, an integer number, a floating point
+	   number or a valid video frame rate abbreviation. The default value
+	   is "25".
+
+       duration, d
+	   Set the duration of the sourced video. See the Time duration
+	   section in the ffmpeg-utils(1) manual for the accepted syntax.
+
+	   If not specified, or the expressed duration is negative, the video
+	   is supposed to be generated forever.
+
+	   Since the frame rate is used as time base, all frames including the
+	   last one will have their full duration. If the specified duration
+	   is not a multiple of the frame duration, it will be rounded up.
+
+       sar Set the sample aspect ratio of the sourced video.
+
+       alpha
+	   Specify the alpha (opacity) of the background, only available in
+	   the "testsrc2" source. The value must be between 0 (fully
+	   transparent) and 255 (fully opaque, the default).
+
+       decimals, n
+	   Set the number of decimals to show in the timestamp, only available
+	   in the "testsrc" source.
+
+	   The displayed timestamp value will correspond to the original
+	   timestamp value multiplied by the power of 10 of the specified
+	   value. Default value is 0.
+
+       type
+	   Set the type of the color spectrum, only available in the
+	   "colorspectrum" source. Can be one of the following:
+
+	   black
+	   white
+	   all
+       patch_size
+	   Set patch size of single color patch, only available in the
+	   "colorchart" source. Default is "64x64".
+
+       preset
+	   Set colorchecker colors preset, only available in the "colorchart"
+	   source.
+
+	   Available values are:
+
+	   reference
+	   skintones
+
+	   Default value is "reference".
+
+       Examples
+
+       o   Generate a video with a duration of 5.3 seconds, with size 176x144
+	   and a frame rate of 10 frames per second:
+
+		   testsrc=duration=5.3:size=qcif:rate=10
+
+       o   The following graph description will generate a red source with an
+	   opacity of 0.2, with size "qcif" and a frame rate of 10 frames per
+	   second:
+
+		   color=c=red@0.2:s=qcif:r=10
+
+       o   If the input content is to be ignored, "nullsrc" can be used. The
+	   following command generates noise in the luminance plane by
+	   employing the "geq" filter:
+
+		   nullsrc=s=256x256, geq=random(1)*255:128:128
+
+       Commands
+
+       The "color" source supports the following commands:
+
+       c, color
+	   Set the color of the created image. Accepts the same syntax of the
+	   corresponding color option.
+
+   openclsrc
+       Generate video using an OpenCL program.
+
+       source
+	   OpenCL program source file.
+
+       kernel
+	   Kernel name in program.
+
+       size, s
+	   Size of frames to generate.	This must be set.
+
+       format
+	   Pixel format to use for the generated frames.  This must be set.
+
+       rate, r
+	   Number of frames generated every second.  Default value is '25'.
+
+       For details of how the program loading works, see the program_opencl
+       filter.
+
+       Example programs:
+
+       o   Generate a colour ramp by setting pixel values from the position of
+	   the pixel in the output image.  (Note that this will work with all
+	   pixel formats, but the generated output will not be the same.)
+
+		   __kernel void ramp(__write_only image2d_t dst,
+				      unsigned int index)
+		   {
+		       int2 loc = (int2)(get_global_id(0), get_global_id(1));
+
+		       float4 val;
+		       val.xy = val.zw = convert_float2(loc) / convert_float2(get_image_dim(dst));
+
+		       write_imagef(dst, loc, val);
+		   }
+
+       o   Generate a Sierpinski carpet pattern, panning by a single pixel
+	   each frame.
+
+		   __kernel void sierpinski_carpet(__write_only image2d_t dst,
+						   unsigned int index)
+		   {
+		       int2 loc = (int2)(get_global_id(0), get_global_id(1));
+
+		       float4 value = 0.0f;
+		       int x = loc.x + index;
+		       int y = loc.y + index;
+		       while (x > 0 || y > 0) {
+			   if (x % 3 == 1 && y % 3 == 1) {
+			       value = 1.0f;
+			       break;
+			   }
+			   x /= 3;
+			   y /= 3;
+		       }
+
+		       write_imagef(dst, loc, value);
+		   }
+
+   sierpinski
+       Generate a Sierpinski carpet/triangle fractal, and randomly pan around.
+
+       This source accepts the following options:
+
+       size, s
+	   Set frame size. For the syntax of this option, check the "Video
+	   size" section in the ffmpeg-utils manual. Default value is
+	   "640x480".
+
+       rate, r
+	   Set frame rate, expressed as number of frames per second. Default
+	   value is "25".
+
+       seed
+	   Set seed which is used for random panning.
+
+       jump
+	   Set max jump for single pan destination. Allowed range is from 1 to
+	   10000.
+
+       type
+	   Set fractal type, can be default "carpet" or "triangle".
+
+VIDEO SINKS
+       Below is a description of the currently available video sinks.
+
+   buffersink
+       Buffer video frames, and make them available to the end of the filter
+       graph.
+
+       This sink is mainly intended for programmatic use, in particular
+       through the interface defined in libavfilter/buffersink.h or the
+       options system.
+
+       It accepts a pointer to an AVBufferSinkContext structure, which defines
+       the incoming buffers' formats, to be passed as the opaque parameter to
+       "avfilter_init_filter" for initialization.
+
+   nullsink
+       Null video sink: do absolutely nothing with the input video. It is
+       mainly useful as a template and for use in analysis / debugging tools.
+
+MULTIMEDIA FILTERS
+       Below is a description of the currently available multimedia filters.
+
+   a3dscope
+       Convert input audio to 3d scope video output.
+
+       The filter accepts the following options:
+
+       rate, r
+	   Set frame rate, expressed as number of frames per second. Default
+	   value is "25".
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "hd720".
+
+       fov Set the camera field of view. Default is 90 degrees.  Allowed range
+	   is from 40 to 150.
+
+       roll
+	   Set the camera roll.
+
+       pitch
+	   Set the camera pitch.
+
+       yaw Set the camera yaw.
+
+       xzoom
+	   Set the camera zoom on X-axis.
+
+       yzoom
+	   Set the camera zoom on Y-axis.
+
+       zzoom
+	   Set the camera zoom on Z-axis.
+
+       xpos
+	   Set the camera position on X-axis.
+
+       ypos
+	   Set the camera position on Y-axis.
+
+       zpos
+	   Set the camera position on Z-axis.
+
+       length
+	   Set the length of displayed audio waves in number of frames.
+
+       Commands
+
+       Filter supports the some above options as commands.
+
+   abitscope
+       Convert input audio to a video output, displaying the audio bit scope.
+
+       The filter accepts the following options:
+
+       rate, r
+	   Set frame rate, expressed as number of frames per second. Default
+	   value is "25".
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "1024x256".
+
+       colors
+	   Specify list of colors separated by space or by '|' which will be
+	   used to draw channels. Unrecognized or missing colors will be
+	   replaced by white color.
+
+       mode, m
+	   Set output mode. Can be "bars" or "trace". Default is "bars".
+
+   adrawgraph
+       Draw a graph using input audio metadata.
+
+       See drawgraph
+
+   agraphmonitor
+       See graphmonitor.
+
+   ahistogram
+       Convert input audio to a video output, displaying the volume histogram.
+
+       The filter accepts the following options:
+
+       dmode
+	   Specify how histogram is calculated.
+
+	   It accepts the following values:
+
+	   single
+	       Use single histogram for all channels.
+
+	   separate
+	       Use separate histogram for each channel.
+
+	   Default is "single".
+
+       rate, r
+	   Set frame rate, expressed as number of frames per second. Default
+	   value is "25".
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "hd720".
+
+       scale
+	   Set display scale.
+
+	   It accepts the following values:
+
+	   log logarithmic
+
+	   sqrt
+	       square root
+
+	   cbrt
+	       cubic root
+
+	   lin linear
+
+	   rlog
+	       reverse logarithmic
+
+	   Default is "log".
+
+       ascale
+	   Set amplitude scale.
+
+	   It accepts the following values:
+
+	   log logarithmic
+
+	   lin linear
+
+	   Default is "log".
+
+       acount
+	   Set how much frames to accumulate in histogram.  Default is 1.
+	   Setting this to -1 accumulates all frames.
+
+       rheight
+	   Set histogram ratio of window height.
+
+       slide
+	   Set sonogram sliding.
+
+	   It accepts the following values:
+
+	   replace
+	       replace old rows with new ones.
+
+	   scroll
+	       scroll from top to bottom.
+
+	   Default is "replace".
+
+       hmode
+	   Set histogram mode.
+
+	   It accepts the following values:
+
+	   abs Use absolute values of samples.
+
+	   sign
+	       Use untouched values of samples.
+
+	   Default is "abs".
+
+   aphasemeter
+       Measures phase of input audio, which is exported as metadata
+       "lavfi.aphasemeter.phase", representing mean phase of current audio
+       frame. A video output can also be produced and is enabled by default.
+       The audio is passed through as first output.
+
+       Audio will be rematrixed to stereo if it has a different channel
+       layout. Phase value is in range "[-1, 1]" where "-1" means left and
+       right channels are completely out of phase and 1 means channels are in
+       phase.
+
+       The filter accepts the following options, all related to its video
+       output:
+
+       rate, r
+	   Set the output frame rate. Default value is 25.
+
+       size, s
+	   Set the video size for the output. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.  Default
+	   value is "800x400".
+
+       rc
+       gc
+       bc  Specify the red, green, blue contrast. Default values are 2, 7 and
+	   1.  Allowed range is "[0, 255]".
+
+       mpc Set color which will be used for drawing median phase. If color is
+	   "none" which is default, no median phase value will be drawn.
+
+       video
+	   Enable video output. Default is enabled.
+
+       phasing detection
+
+       The filter also detects out of phase and mono sequences in stereo
+       streams.  It logs the sequence start, end and duration when it lasts
+       longer or as long as the minimum set.
+
+       The filter accepts the following options for this detection:
+
+       phasing
+	   Enable mono and out of phase detection. Default is disabled.
+
+       tolerance, t
+	   Set phase tolerance for mono detection, in amplitude ratio. Default
+	   is 0.  Allowed range is "[0, 1]".
+
+       angle, a
+	   Set angle threshold for out of phase detection, in degree. Default
+	   is 170.  Allowed range is "[90, 180]".
+
+       duration, d
+	   Set mono or out of phase duration until notification, expressed in
+	   seconds. Default is 2.
+
+       Examples
+
+       o   Complete example with ffmpeg to detect 1 second of mono with 0.001
+	   phase tolerance:
+
+		   ffmpeg -i stereo.wav -af aphasemeter=video=0:phasing=1:duration=1:tolerance=0.001 -f null -
+
+   avectorscope
+       Convert input audio to a video output, representing the audio vector
+       scope.
+
+       The filter is used to measure the difference between channels of stereo
+       audio stream. A monaural signal, consisting of identical left and right
+       signal, results in straight vertical line. Any stereo separation is
+       visible as a deviation from this line, creating a Lissajous figure.  If
+       the straight (or deviation from it) but horizontal line appears this
+       indicates that the left and right channels are out of phase.
+
+       The filter accepts the following options:
+
+       mode, m
+	   Set the vectorscope mode.
+
+	   Available values are:
+
+	   lissajous
+	       Lissajous rotated by 45 degrees.
+
+	   lissajous_xy
+	       Same as above but not rotated.
+
+	   polar
+	       Shape resembling half of circle.
+
+	   Default value is lissajous.
+
+       size, s
+	   Set the video size for the output. For the syntax of this option,
+	   check the "Video size" section in the ffmpeg-utils manual.  Default
+	   value is "400x400".
+
+       rate, r
+	   Set the output frame rate. Default value is 25.
+
+       rc
+       gc
+       bc
+       ac  Specify the red, green, blue and alpha contrast. Default values are
+	   40, 160, 80 and 255.  Allowed range is "[0, 255]".
+
+       rf
+       gf
+       bf
+       af  Specify the red, green, blue and alpha fade. Default values are 15,
+	   10, 5 and 5.  Allowed range is "[0, 255]".
+
+       zoom
+	   Set the zoom factor. Default value is 1. Allowed range is "[0,
+	   10]".  Values lower than 1 will auto adjust zoom factor to maximal
+	   possible value.
+
+       draw
+	   Set the vectorscope drawing mode.
+
+	   Available values are:
+
+	   dot Draw dot for each sample.
+
+	   line
+	       Draw line between previous and current sample.
+
+	   aaline
+	       Draw anti-aliased line between previous and current sample.
+
+	   Default value is dot.
+
+       scale
+	   Specify amplitude scale of audio samples.
+
+	   Available values are:
+
+	   lin Linear.
+
+	   sqrt
+	       Square root.
+
+	   cbrt
+	       Cubic root.
+
+	   log Logarithmic.
+
+       swap
+	   Swap left channel axis with right channel axis.
+
+       mirror
+	   Mirror axis.
+
+	   none
+	       No mirror.
+
+	   x   Mirror only x axis.
+
+	   y   Mirror only y axis.
+
+	   xy  Mirror both axis.
+
+       Examples
+
+       o   Complete example using ffplay:
+
+		   ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
+				[a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
+
+       Commands
+
+       This filter supports the all above options as commands except options
+       "size" and "rate".
+
+   bench, abench
+       Benchmark part of a filtergraph.
+
+       The filter accepts the following options:
+
+       action
+	   Start or stop a timer.
+
+	   Available values are:
+
+	   start
+	       Get the current time, set it as frame metadata (using the key
+	       "lavfi.bench.start_time"), and forward the frame to the next
+	       filter.
+
+	   stop
+	       Get the current time and fetch the "lavfi.bench.start_time"
+	       metadata from the input frame metadata to get the time
+	       difference. Time difference, average, maximum and minimum time
+	       (respectively "t", "avg", "max" and "min") are then printed.
+	       The timestamps are expressed in seconds.
+
+       Examples
+
+       o   Benchmark selectivecolor filter:
+
+		   bench=start,selectivecolor=reds=-.2 .12 -.49,bench=stop
+
+   concat
+       Concatenate audio and video streams, joining them together one after
+       the other.
+
+       The filter works on segments of synchronized video and audio streams.
+       All segments must have the same number of streams of each type, and
+       that will also be the number of streams at output.
+
+       The filter accepts the following options:
+
+       n   Set the number of segments. Default is 2.
+
+       v   Set the number of output video streams, that is also the number of
+	   video streams in each segment. Default is 1.
+
+       a   Set the number of output audio streams, that is also the number of
+	   audio streams in each segment. Default is 0.
+
+       unsafe
+	   Activate unsafe mode: do not fail if segments have a different
+	   format.
+
+       The filter has v+a outputs: first v video outputs, then a audio
+       outputs.
+
+       There are nx(v+a) inputs: first the inputs for the first segment, in
+       the same order as the outputs, then the inputs for the second segment,
+       etc.
+
+       Related streams do not always have exactly the same duration, for
+       various reasons including codec frame size or sloppy authoring. For
+       that reason, related synchronized streams (e.g. a video and its audio
+       track) should be concatenated at once. The concat filter will use the
+       duration of the longest stream in each segment (except the last one),
+       and if necessary pad shorter audio streams with silence.
+
+       For this filter to work correctly, all segments must start at timestamp
+       0.
+
+       All corresponding streams must have the same parameters in all
+       segments; the filtering system will automatically select a common pixel
+       format for video streams, and a common sample format, sample rate and
+       channel layout for audio streams, but other settings, such as
+       resolution, must be converted explicitly by the user.
+
+       Different frame rates are acceptable but will result in variable frame
+       rate at output; be sure to configure the output file to handle it.
+
+       Examples
+
+       o   Concatenate an opening, an episode and an ending, all in bilingual
+	   version (video in stream 0, audio in streams 1 and 2):
+
+		   ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv -filter_complex \
+		     '[0:0] [0:1] [0:2] [1:0] [1:1] [1:2] [2:0] [2:1] [2:2]
+		      concat=n=3:v=1:a=2 [v] [a1] [a2]' \
+		     -map '[v]' -map '[a1]' -map '[a2]' output.mkv
+
+       o   Concatenate two parts, handling audio and video separately, using
+	   the (a)movie sources, and adjusting the resolution:
+
+		   movie=part1.mp4, scale=512:288 [v1] ; amovie=part1.mp4 [a1] ;
+		   movie=part2.mp4, scale=512:288 [v2] ; amovie=part2.mp4 [a2] ;
+		   [v1] [v2] concat [outv] ; [a1] [a2] concat=v=0:a=1 [outa]
+
+	   Note that a desync will happen at the stitch if the audio and video
+	   streams do not have exactly the same duration in the first file.
+
+       Commands
+
+       This filter supports the following commands:
+
+       next
+	   Close the current segment and step to the next one
+
+   ebur128
+       EBU R128 scanner filter. This filter takes an audio stream and analyzes
+       its loudness level. By default, it logs a message at a frequency of
+       10Hz with the Momentary loudness (identified by "M"), Short-term
+       loudness ("S"), Integrated loudness ("I") and Loudness Range ("LRA").
+
+       The filter can only analyze streams which have sample format is double-
+       precision floating point. The input stream will be converted to this
+       specification, if needed. Users may need to insert aformat and/or
+       aresample filters after this filter to obtain the original parameters.
+
+       The filter also has a video output (see the video option) with a real
+       time graph to observe the loudness evolution. The graphic contains the
+       logged message mentioned above, so it is not printed anymore when this
+       option is set, unless the verbose logging is set. The main graphing
+       area contains the short-term loudness (3 seconds of analysis), and the
+       gauge on the right is for the momentary loudness (400 milliseconds),
+       but can optionally be configured to instead display short-term loudness
+       (see gauge).
+
+       The green area marks a  +/- 1LU target range around the target loudness
+       (-23LUFS by default, unless modified through target).
+
+       More information about the Loudness Recommendation EBU R128 on
+       <http://tech.ebu.ch/loudness>.
+
+       The filter accepts the following options:
+
+       video
+	   Activate the video output. The audio stream is passed unchanged
+	   whether this option is set or no. The video stream will be the
+	   first output stream if activated. Default is 0.
+
+       size
+	   Set the video size. This option is for video only. For the syntax
+	   of this option, check the "Video size" section in the ffmpeg-utils
+	   manual.  Default and minimum resolution is "640x480".
+
+       meter
+	   Set the EBU scale meter. Default is 9. Common values are 9 and 18,
+	   respectively for EBU scale meter +9 and EBU scale meter +18. Any
+	   other integer value between this range is allowed.
+
+       metadata
+	   Set metadata injection. If set to 1, the audio input will be
+	   segmented into 100ms output frames, each of them containing various
+	   loudness information in metadata.  All the metadata keys are
+	   prefixed with "lavfi.r128.".
+
+	   Default is 0.
+
+       framelog
+	   Force the frame logging level.
+
+	   Available values are:
+
+	   quiet
+	       logging disabled
+
+	   info
+	       information logging level
+
+	   verbose
+	       verbose logging level
+
+	   By default, the logging level is set to info. If the video or the
+	   metadata options are set, it switches to verbose.
+
+       peak
+	   Set peak mode(s).
+
+	   Available modes can be cumulated (the option is a "flag" type).
+	   Possible values are:
+
+	   none
+	       Disable any peak mode (default).
+
+	   sample
+	       Enable sample-peak mode.
+
+	       Simple peak mode looking for the higher sample value. It logs a
+	       message for sample-peak (identified by "SPK").
+
+	   true
+	       Enable true-peak mode.
+
+	       If enabled, the peak lookup is done on an over-sampled version
+	       of the input stream for better peak accuracy. It logs a message
+	       for true-peak.  (identified by "TPK") and true-peak per frame
+	       (identified by "FTPK").	This mode requires a build with
+	       "libswresample".
+
+       dualmono
+	   Treat mono input files as "dual mono". If a mono file is intended
+	   for playback on a stereo system, its EBU R128 measurement will be
+	   perceptually incorrect.  If set to "true", this option will
+	   compensate for this effect.	Multi-channel input files are not
+	   affected by this option.
+
+       panlaw
+	   Set a specific pan law to be used for the measurement of dual mono
+	   files.  This parameter is optional, and has a default value of
+	   -3.01dB.
+
+       target
+	   Set a specific target level (in LUFS) used as relative zero in the
+	   visualization.  This parameter is optional and has a default value
+	   of -23LUFS as specified by EBU R128. However, material published
+	   online may prefer a level of -16LUFS (e.g. for use with podcasts or
+	   video platforms).
+
+       gauge
+	   Set the value displayed by the gauge. Valid values are "momentary"
+	   and s "shortterm". By default the momentary value will be used, but
+	   in certain scenarios it may be more useful to observe the short
+	   term value instead (e.g.  live mixing).
+
+       scale
+	   Sets the display scale for the loudness. Valid parameters are
+	   "absolute" (in LUFS) or "relative" (LU) relative to the target.
+	   This only affects the video output, not the summary or continuous
+	   log output.
+
+       Examples
+
+       o   Real-time graph using ffplay, with a EBU scale meter +18:
+
+		   ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
+
+       o   Run an analysis with ffmpeg:
+
+		   ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
+
+   interleave, ainterleave
+       Temporally interleave frames from several inputs.
+
+       "interleave" works with video inputs, "ainterleave" with audio.
+
+       These filters read frames from several inputs and send the oldest
+       queued frame to the output.
+
+       Input streams must have well defined, monotonically increasing frame
+       timestamp values.
+
+       In order to submit one frame to output, these filters need to enqueue
+       at least one frame for each input, so they cannot work in case one
+       input is not yet terminated and will not receive incoming frames.
+
+       For example consider the case when one input is a "select" filter which
+       always drops input frames. The "interleave" filter will keep reading
+       from that input, but it will never be able to send new frames to output
+       until the input sends an end-of-stream signal.
+
+       Also, depending on inputs synchronization, the filters will drop frames
+       in case one input receives more frames than the other ones, and the
+       queue is already filled.
+
+       These filters accept the following options:
+
+       nb_inputs, n
+	   Set the number of different inputs, it is 2 by default.
+
+       duration
+	   How to determine the end-of-stream.
+
+	   longest
+	       The duration of the longest input. (default)
+
+	   shortest
+	       The duration of the shortest input.
+
+	   first
+	       The duration of the first input.
+
+       Examples
+
+       o   Interleave frames belonging to different streams using ffmpeg:
+
+		   ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
+
+       o   Add flickering blur effect:
+
+		   select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
+
+   latency, alatency
+       Measure filtering latency.
+
+       Report previous filter filtering latency, delay in number of audio
+       samples for audio filters or number of video frames for video filters.
+
+       On end of input stream, filter will report min and max measured latency
+       for previous running filter in filtergraph.
+
+   metadata, ametadata
+       Manipulate frame metadata.
+
+       This filter accepts the following options:
+
+       mode
+	   Set mode of operation of the filter.
+
+	   Can be one of the following:
+
+	   select
+	       If both "value" and "key" is set, select frames which have such
+	       metadata. If only "key" is set, select every frame that has
+	       such key in metadata.
+
+	   add Add new metadata "key" and "value". If key is already available
+	       do nothing.
+
+	   modify
+	       Modify value of already present key.
+
+	   delete
+	       If "value" is set, delete only keys that have such value.
+	       Otherwise, delete key. If "key" is not set, delete all metadata
+	       values in the frame.
+
+	   print
+	       Print key and its value if metadata was found. If "key" is not
+	       set print all metadata values available in frame.
+
+       key Set key used with all modes. Must be set for all modes except
+	   "print" and "delete".
+
+       value
+	   Set metadata value which will be used. This option is mandatory for
+	   "modify" and "add" mode.
+
+       function
+	   Which function to use when comparing metadata value and "value".
+
+	   Can be one of following:
+
+	   same_str
+	       Values are interpreted as strings, returns true if metadata
+	       value is same as "value".
+
+	   starts_with
+	       Values are interpreted as strings, returns true if metadata
+	       value starts with the "value" option string.
+
+	   less
+	       Values are interpreted as floats, returns true if metadata
+	       value is less than "value".
+
+	   equal
+	       Values are interpreted as floats, returns true if "value" is
+	       equal with metadata value.
+
+	   greater
+	       Values are interpreted as floats, returns true if metadata
+	       value is greater than "value".
+
+	   expr
+	       Values are interpreted as floats, returns true if expression
+	       from option "expr" evaluates to true.
+
+	   ends_with
+	       Values are interpreted as strings, returns true if metadata
+	       value ends with the "value" option string.
+
+       expr
+	   Set expression which is used when "function" is set to "expr".  The
+	   expression is evaluated through the eval API and can contain the
+	   following constants:
+
+	   VALUE1, FRAMEVAL
+	       Float representation of "value" from metadata key.
+
+	   VALUE2, USERVAL
+	       Float representation of "value" as supplied by user in "value"
+	       option.
+
+       file
+	   If specified in "print" mode, output is written to the named file.
+	   Instead of plain filename any writable url can be specified.
+	   Filename ``-'' is a shorthand for standard output. If "file" option
+	   is not set, output is written to the log with AV_LOG_INFO loglevel.
+
+       direct
+	   Reduces buffering in print mode when output is written to a URL set
+	   using file.
+
+       Examples
+
+       o   Print all metadata values for frames with key
+	   "lavfi.signalstats.YDIF" with values between 0 and 1.
+
+		   signalstats,metadata=print:key=lavfi.signalstats.YDIF:value=0:function=expr:expr='between(VALUE1,0,1)'
+
+       o   Print silencedetect output to file metadata.txt.
+
+		   silencedetect,ametadata=mode=print:file=metadata.txt
+
+       o   Direct all metadata to a pipe with file descriptor 4.
+
+		   metadata=mode=print:file='pipe\:4'
+
+   perms, aperms
+       Set read/write permissions for the output frames.
+
+       These filters are mainly aimed at developers to test direct path in the
+       following filter in the filtergraph.
+
+       The filters accept the following options:
+
+       mode
+	   Select the permissions mode.
+
+	   It accepts the following values:
+
+	   none
+	       Do nothing. This is the default.
+
+	   ro  Set all the output frames read-only.
+
+	   rw  Set all the output frames directly writable.
+
+	   toggle
+	       Make the frame read-only if writable, and writable if read-
+	       only.
+
+	   random
+	       Set each output frame read-only or writable randomly.
+
+       seed
+	   Set the seed for the random mode, must be an integer included
+	   between 0 and "UINT32_MAX". If not specified, or if explicitly set
+	   to "-1", the filter will try to use a good random seed on a best
+	   effort basis.
+
+       Note: in case of auto-inserted filter between the permission filter and
+       the following one, the permission might not be received as expected in
+       that following filter. Inserting a format or aformat filter before the
+       perms/aperms filter can avoid this problem.
+
+   realtime, arealtime
+       Slow down filtering to match real time approximately.
+
+       These filters will pause the filtering for a variable amount of time to
+       match the output rate with the input timestamps.  They are similar to
+       the re option to "ffmpeg".
+
+       They accept the following options:
+
+       limit
+	   Time limit for the pauses. Any pause longer than that will be
+	   considered a timestamp discontinuity and reset the timer. Default
+	   is 2 seconds.
+
+       speed
+	   Speed factor for processing. The value must be a float larger than
+	   zero.  Values larger than 1.0 will result in faster than realtime
+	   processing, smaller will slow processing down. The limit is
+	   automatically adapted accordingly. Default is 1.0.
+
+	   A processing speed faster than what is possible without these
+	   filters cannot be achieved.
+
+       Commands
+
+       Both filters supports the all above options as commands.
+
+   segment, asegment
+       Split single input stream into multiple streams.
+
+       This filter does opposite of concat filters.
+
+       "segment" works on video frames, "asegment" on audio samples.
+
+       This filter accepts the following options:
+
+       timestamps
+	   Timestamps of output segments separated by '|'. The first segment
+	   will run from the beginning of the input stream. The last segment
+	   will run until the end of the input stream
+
+       frames, samples
+	   Exact frame/sample count to split the segments.
+
+       In all cases, prefixing an each segment with '+' will make it relative
+       to the previous segment.
+
+       Examples
+
+       o   Split input audio stream into three output audio streams, starting
+	   at start of input audio stream and storing that in 1st output audio
+	   stream, then following at 60th second and storing than in 2nd
+	   output audio stream, and last after 150th second of input audio
+	   stream store in 3rd output audio stream:
+
+		   asegment=timestamps="60|150"
+
+   select, aselect
+       Select frames to pass in output.
+
+       This filter accepts the following options:
+
+       expr, e
+	   Set expression, which is evaluated for each input frame.
+
+	   If the expression is evaluated to zero, the frame is discarded.
+
+	   If the evaluation result is negative or NaN, the frame is sent to
+	   the first output; otherwise it is sent to the output with index
+	   "ceil(val)-1", assuming that the input index starts from 0.
+
+	   For example a value of 1.2 corresponds to the output with index
+	   "ceil(1.2)-1 = 2-1 = 1", that is the second output.
+
+       outputs, n
+	   Set the number of outputs. The output to which to send the selected
+	   frame is based on the result of the evaluation. Default value is 1.
+
+       The expression can contain the following constants:
+
+       n   The (sequential) number of the filtered frame, starting from 0.
+
+       selected_n
+	   The (sequential) number of the selected frame, starting from 0.
+
+       prev_selected_n
+	   The sequential number of the last selected frame. It's NAN if
+	   undefined.
+
+       TB  The timebase of the input timestamps.
+
+       pts The PTS (Presentation TimeStamp) of the filtered frame, expressed
+	   in TB units. It's NAN if undefined.
+
+       t   The PTS of the filtered frame, expressed in seconds. It's NAN if
+	   undefined.
+
+       prev_pts
+	   The PTS of the previously filtered frame. It's NAN if undefined.
+
+       prev_selected_pts
+	   The PTS of the last previously filtered frame. It's NAN if
+	   undefined.
+
+       prev_selected_t
+	   The PTS of the last previously selected frame, expressed in
+	   seconds. It's NAN if undefined.
+
+       start_pts
+	   The first PTS in the stream which is not NAN. It remains NAN if not
+	   found.
+
+       start_t
+	   The first PTS, in seconds, in the stream which is not NAN. It
+	   remains NAN if not found.
+
+       pict_type (video only)
+	   The type of the filtered frame. It can assume one of the following
+	   values:
+
+	   I
+	   P
+	   B
+	   S
+	   SI
+	   SP
+	   BI
+       interlace_type (video only)
+	   The frame interlace type. It can assume one of the following
+	   values:
+
+	   PROGRESSIVE
+	       The frame is progressive (not interlaced).
+
+	   TOPFIRST
+	       The frame is top-field-first.
+
+	   BOTTOMFIRST
+	       The frame is bottom-field-first.
+
+       consumed_sample_n (audio only)
+	   the number of selected samples before the current frame
+
+       samples_n (audio only)
+	   the number of samples in the current frame
+
+       sample_rate (audio only)
+	   the input sample rate
+
+       key This is 1 if the filtered frame is a key-frame, 0 otherwise.
+
+       pos the position in the file of the filtered frame, -1 if the
+	   information is not available (e.g. for synthetic video)
+
+       scene (video only)
+	   value between 0 and 1 to indicate a new scene; a low value reflects
+	   a low probability for the current frame to introduce a new scene,
+	   while a higher value means the current frame is more likely to be
+	   one (see the example below)
+
+       concatdec_select
+	   The concat demuxer can select only part of a concat input file by
+	   setting an inpoint and an outpoint, but the output packets may not
+	   be entirely contained in the selected interval. By using this
+	   variable, it is possible to skip frames generated by the concat
+	   demuxer which are not exactly contained in the selected interval.
+
+	   This works by comparing the frame pts against the
+	   lavf.concat.start_time and the lavf.concat.duration packet metadata
+	   values which are also present in the decoded frames.
+
+	   The concatdec_select variable is -1 if the frame pts is at least
+	   start_time and either the duration metadata is missing or the frame
+	   pts is less than start_time + duration, 0 otherwise, and NaN if the
+	   start_time metadata is missing.
+
+	   That basically means that an input frame is selected if its pts is
+	   within the interval set by the concat demuxer.
+
+       The default value of the select expression is "1".
+
+       Examples
+
+       o   Select all frames in input:
+
+		   select
+
+	   The example above is the same as:
+
+		   select=1
+
+       o   Skip all frames:
+
+		   select=0
+
+       o   Select only I-frames:
+
+		   select='eq(pict_type\,I)'
+
+       o   Select one frame every 100:
+
+		   select='not(mod(n\,100))'
+
+       o   Select only frames contained in the 10-20 time interval:
+
+		   select=between(t\,10\,20)
+
+       o   Select only I-frames contained in the 10-20 time interval:
+
+		   select=between(t\,10\,20)*eq(pict_type\,I)
+
+       o   Select frames with a minimum distance of 10 seconds:
+
+		   select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
+
+       o   Use aselect to select only audio frames with samples number > 100:
+
+		   aselect='gt(samples_n\,100)'
+
+       o   Create a mosaic of the first scenes:
+
+		   ffmpeg -i video.avi -vf select='gt(scene\,0.4)',scale=160:120,tile -frames:v 1 preview.png
+
+	   Comparing scene against a value between 0.3 and 0.5 is generally a
+	   sane choice.
+
+       o   Send even and odd frames to separate outputs, and compose them:
+
+		   select=n=2:e='mod(n, 2)+1' [odd][even]; [odd] pad=h=2*ih [tmp]; [tmp][even] overlay=y=h
+
+       o   Select useful frames from an ffconcat file which is using inpoints
+	   and outpoints but where the source files are not intra frame only.
+
+		   ffmpeg -copyts -vsync 0 -segment_time_metadata 1 -i input.ffconcat -vf select=concatdec_select -af aselect=concatdec_select output.avi
+
+   sendcmd, asendcmd
+       Send commands to filters in the filtergraph.
+
+       These filters read commands to be sent to other filters in the
+       filtergraph.
+
+       "sendcmd" must be inserted between two video filters, "asendcmd" must
+       be inserted between two audio filters, but apart from that they act the
+       same way.
+
+       The specification of commands can be provided in the filter arguments
+       with the commands option, or in a file specified by the filename
+       option.
+
+       These filters accept the following options:
+
+       commands, c
+	   Set the commands to be read and sent to the other filters.
+
+       filename, f
+	   Set the filename of the commands to be read and sent to the other
+	   filters.
+
+       Commands syntax
+
+       A commands description consists of a sequence of interval
+       specifications, comprising a list of commands to be executed when a
+       particular event related to that interval occurs. The occurring event
+       is typically the current frame time entering or leaving a given time
+       interval.
+
+       An interval is specified by the following syntax:
+
+	       <START>[-<END>] <COMMANDS>;
+
+       The time interval is specified by the START and END times.  END is
+       optional and defaults to the maximum time.
+
+       The current frame time is considered within the specified interval if
+       it is included in the interval [START, END), that is when the time is
+       greater or equal to START and is lesser than END.
+
+       COMMANDS consists of a sequence of one or more command specifications,
+       separated by ",", relating to that interval.  The syntax of a command
+       specification is given by:
+
+	       [<FLAGS>] <TARGET> <COMMAND> <ARG>
+
+       FLAGS is optional and specifies the type of events relating to the time
+       interval which enable sending the specified command, and must be a non-
+       null sequence of identifier flags separated by "+" or "|" and enclosed
+       between "[" and "]".
+
+       The following flags are recognized:
+
+       enter
+	   The command is sent when the current frame timestamp enters the
+	   specified interval. In other words, the command is sent when the
+	   previous frame timestamp was not in the given interval, and the
+	   current is.
+
+       leave
+	   The command is sent when the current frame timestamp leaves the
+	   specified interval. In other words, the command is sent when the
+	   previous frame timestamp was in the given interval, and the current
+	   is not.
+
+       expr
+	   The command ARG is interpreted as expression and result of
+	   expression is passed as ARG.
+
+	   The expression is evaluated through the eval API and can contain
+	   the following constants:
+
+	   POS Original position in the file of the frame, or undefined if
+	       undefined for the current frame.
+
+	   PTS The presentation timestamp in input.
+
+	   N   The count of the input frame for video or audio, starting from
+	       0.
+
+	   T   The time in seconds of the current frame.
+
+	   TS  The start time in seconds of the current command interval.
+
+	   TE  The end time in seconds of the current command interval.
+
+	   TI  The interpolated time of the current command interval, TI = (T
+	       - TS) / (TE - TS).
+
+	   W   The video frame width.
+
+	   H   The video frame height.
+
+       If FLAGS is not specified, a default value of "[enter]" is assumed.
+
+       TARGET specifies the target of the command, usually the name of the
+       filter class or a specific filter instance name.
+
+       COMMAND specifies the name of the command for the target filter.
+
+       ARG is optional and specifies the optional list of argument for the
+       given COMMAND.
+
+       Between one interval specification and another, whitespaces, or
+       sequences of characters starting with "#" until the end of line, are
+       ignored and can be used to annotate comments.
+
+       A simplified BNF description of the commands specification syntax
+       follows:
+
+	       <COMMAND_FLAG>  ::= "enter" | "leave"
+	       <COMMAND_FLAGS> ::= <COMMAND_FLAG> [(+|"|")<COMMAND_FLAG>]
+	       <COMMAND>       ::= ["[" <COMMAND_FLAGS> "]"] <TARGET> <COMMAND> [<ARG>]
+	       <COMMANDS>      ::= <COMMAND> [,<COMMANDS>]
+	       <INTERVAL>      ::= <START>[-<END>] <COMMANDS>
+	       <INTERVALS>     ::= <INTERVAL>[;<INTERVALS>]
+
+       Examples
+
+       o   Specify audio tempo change at second 4:
+
+		   asendcmd=c='4.0 atempo tempo 1.5',atempo
+
+       o   Target a specific filter instance:
+
+		   asendcmd=c='4.0 atempo@my tempo 1.5',atempo@my
+
+       o   Specify a list of drawtext and hue commands in a file.
+
+		   # show text in the interval 5-10
+		   5.0-10.0 [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=hello world',
+			    [leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=';
+
+		   # desaturate the image in the interval 15-20
+		   15.0-20.0 [enter] hue s 0,
+			     [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=nocolor',
+			     [leave] hue s 1,
+			     [leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=color';
+
+		   # apply an exponential saturation fade-out effect, starting from time 25
+		   25 [enter] hue s exp(25-t)
+
+	   A filtergraph allowing to read and process the above command list
+	   stored in a file test.cmd, can be specified with:
+
+		   sendcmd=f=test.cmd,drawtext=fontfile=FreeSerif.ttf:text='',hue
+
+   setpts, asetpts
+       Change the PTS (presentation timestamp) of the input frames.
+
+       "setpts" works on video frames, "asetpts" on audio frames.
+
+       This filter accepts the following options:
+
+       expr
+	   The expression which is evaluated for each frame to construct its
+	   timestamp.
+
+       The expression is evaluated through the eval API and can contain the
+       following constants:
+
+       FRAME_RATE, FR
+	   frame rate, only defined for constant frame-rate video
+
+       PTS The presentation timestamp in input
+
+       N   The count of the input frame for video or the number of consumed
+	   samples, not including the current frame for audio, starting from
+	   0.
+
+       NB_CONSUMED_SAMPLES
+	   The number of consumed samples, not including the current frame
+	   (only audio)
+
+       NB_SAMPLES, S
+	   The number of samples in the current frame (only audio)
+
+       SAMPLE_RATE, SR
+	   The audio sample rate.
+
+       STARTPTS
+	   The PTS of the first frame.
+
+       STARTT
+	   the time in seconds of the first frame
+
+       INTERLACED
+	   State whether the current frame is interlaced.
+
+       T   the time in seconds of the current frame
+
+       POS original position in the file of the frame, or undefined if
+	   undefined for the current frame
+
+       PREV_INPTS
+	   The previous input PTS.
+
+       PREV_INT
+	   previous input time in seconds
+
+       PREV_OUTPTS
+	   The previous output PTS.
+
+       PREV_OUTT
+	   previous output time in seconds
+
+       RTCTIME
+	   The wallclock (RTC) time in microseconds. This is deprecated, use
+	   time(0) instead.
+
+       RTCSTART
+	   The wallclock (RTC) time at the start of the movie in microseconds.
+
+       TB  The timebase of the input timestamps.
+
+       Examples
+
+       o   Start counting PTS from zero
+
+		   setpts=PTS-STARTPTS
+
+       o   Apply fast motion effect:
+
+		   setpts=0.5*PTS
+
+       o   Apply slow motion effect:
+
+		   setpts=2.0*PTS
+
+       o   Set fixed rate of 25 frames per second:
+
+		   setpts=N/(25*TB)
+
+       o   Set fixed rate 25 fps with some jitter:
+
+		   setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
+
+       o   Apply an offset of 10 seconds to the input PTS:
+
+		   setpts=PTS+10/TB
+
+       o   Generate timestamps from a "live source" and rebase onto the
+	   current timebase:
+
+		   setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
+
+       o   Generate timestamps by counting samples:
+
+		   asetpts=N/SR/TB
+
+   setrange
+       Force color range for the output video frame.
+
+       The "setrange" filter marks the color range property for the output
+       frames. It does not change the input frame, but only sets the
+       corresponding property, which affects how the frame is treated by
+       following filters.
+
+       The filter accepts the following options:
+
+       range
+	   Available values are:
+
+	   auto
+	       Keep the same color range property.
+
+	   unspecified, unknown
+	       Set the color range as unspecified.
+
+	   limited, tv, mpeg
+	       Set the color range as limited.
+
+	   full, pc, jpeg
+	       Set the color range as full.
+
+   settb, asettb
+       Set the timebase to use for the output frames timestamps.  It is mainly
+       useful for testing timebase configuration.
+
+       It accepts the following parameters:
+
+       expr, tb
+	   The expression which is evaluated into the output timebase.
+
+       The value for tb is an arithmetic expression representing a rational.
+       The expression can contain the constants "AVTB" (the default timebase),
+       "intb" (the input timebase) and "sr" (the sample rate, audio only).
+       Default value is "intb".
+
+       Examples
+
+       o   Set the timebase to 1/25:
+
+		   settb=expr=1/25
+
+       o   Set the timebase to 1/10:
+
+		   settb=expr=0.1
+
+       o   Set the timebase to 1001/1000:
+
+		   settb=1+0.001
+
+       o   Set the timebase to 2*intb:
+
+		   settb=2*intb
+
+       o   Set the default timebase value:
+
+		   settb=AVTB
+
+   showcqt
+       Convert input audio to a video output representing frequency spectrum
+       logarithmically using Brown-Puckette constant Q transform algorithm
+       with direct frequency domain coefficient calculation (but the transform
+       itself is not really constant Q, instead the Q factor is actually
+       variable/clamped), with musical tone scale, from E0 to D#10.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. It must be even. For the
+	   syntax of this option, check the "Video size" section in the
+	   ffmpeg-utils manual.  Default value is "1920x1080".
+
+       fps, rate, r
+	   Set the output frame rate. Default value is 25.
+
+       bar_h
+	   Set the bargraph height. It must be even. Default value is "-1"
+	   which computes the bargraph height automatically.
+
+       axis_h
+	   Set the axis height. It must be even. Default value is "-1" which
+	   computes the axis height automatically.
+
+       sono_h
+	   Set the sonogram height. It must be even. Default value is "-1"
+	   which computes the sonogram height automatically.
+
+       fullhd
+	   Set the fullhd resolution. This option is deprecated, use size, s
+	   instead. Default value is 1.
+
+       sono_v, volume
+	   Specify the sonogram volume expression. It can contain variables:
+
+	   bar_v
+	       the bar_v evaluated expression
+
+	   frequency, freq, f
+	       the frequency where it is evaluated
+
+	   timeclamp, tc
+	       the value of timeclamp option
+
+	   and functions:
+
+	   a_weighting(f)
+	       A-weighting of equal loudness
+
+	   b_weighting(f)
+	       B-weighting of equal loudness
+
+	   c_weighting(f)
+	       C-weighting of equal loudness.
+
+	   Default value is 16.
+
+       bar_v, volume2
+	   Specify the bargraph volume expression. It can contain variables:
+
+	   sono_v
+	       the sono_v evaluated expression
+
+	   frequency, freq, f
+	       the frequency where it is evaluated
+
+	   timeclamp, tc
+	       the value of timeclamp option
+
+	   and functions:
+
+	   a_weighting(f)
+	       A-weighting of equal loudness
+
+	   b_weighting(f)
+	       B-weighting of equal loudness
+
+	   c_weighting(f)
+	       C-weighting of equal loudness.
+
+	   Default value is "sono_v".
+
+       sono_g, gamma
+	   Specify the sonogram gamma. Lower gamma makes the spectrum more
+	   contrast, higher gamma makes the spectrum having more range.
+	   Default value is 3.	Acceptable range is "[1, 7]".
+
+       bar_g, gamma2
+	   Specify the bargraph gamma. Default value is 1. Acceptable range is
+	   "[1, 7]".
+
+       bar_t
+	   Specify the bargraph transparency level. Lower value makes the
+	   bargraph sharper.  Default value is 1. Acceptable range is "[0,
+	   1]".
+
+       timeclamp, tc
+	   Specify the transform timeclamp. At low frequency, there is trade-
+	   off between accuracy in time domain and frequency domain. If
+	   timeclamp is lower, event in time domain is represented more
+	   accurately (such as fast bass drum), otherwise event in frequency
+	   domain is represented more accurately (such as bass guitar).
+	   Acceptable range is "[0.002, 1]". Default value is 0.17.
+
+       attack
+	   Set attack time in seconds. The default is 0 (disabled). Otherwise,
+	   it limits future samples by applying asymmetric windowing in time
+	   domain, useful when low latency is required. Accepted range is "[0,
+	   1]".
+
+       basefreq
+	   Specify the transform base frequency. Default value is
+	   20.01523126408007475, which is frequency 50 cents below E0.
+	   Acceptable range is "[10, 100000]".
+
+       endfreq
+	   Specify the transform end frequency. Default value is
+	   20495.59681441799654, which is frequency 50 cents above D#10.
+	   Acceptable range is "[10, 100000]".
+
+       coeffclamp
+	   This option is deprecated and ignored.
+
+       tlength
+	   Specify the transform length in time domain. Use this option to
+	   control accuracy trade-off between time domain and frequency domain
+	   at every frequency sample.  It can contain variables:
+
+	   frequency, freq, f
+	       the frequency where it is evaluated
+
+	   timeclamp, tc
+	       the value of timeclamp option.
+
+	   Default value is "384*tc/(384+tc*f)".
+
+       count
+	   Specify the transform count for every video frame. Default value is
+	   6.  Acceptable range is "[1, 30]".
+
+       fcount
+	   Specify the transform count for every single pixel. Default value
+	   is 0, which makes it computed automatically. Acceptable range is
+	   "[0, 10]".
+
+       fontfile
+	   Specify font file for use with freetype to draw the axis. If not
+	   specified, use embedded font. Note that drawing with font file or
+	   embedded font is not implemented with custom basefreq and endfreq,
+	   use axisfile option instead.
+
+       font
+	   Specify fontconfig pattern. This has lower priority than fontfile.
+	   The ":" in the pattern may be replaced by "|" to avoid unnecessary
+	   escaping.
+
+       fontcolor
+	   Specify font color expression. This is arithmetic expression that
+	   should return integer value 0xRRGGBB. It can contain variables:
+
+	   frequency, freq, f
+	       the frequency where it is evaluated
+
+	   timeclamp, tc
+	       the value of timeclamp option
+
+	   and functions:
+
+	   midi(f)
+	       midi number of frequency f, some midi numbers: E0(16), C1(24),
+	       C2(36), A4(69)
+
+	   r(x), g(x), b(x)
+	       red, green, and blue value of intensity x.
+
+	   Default value is "st(0, (midi(f)-59.5)/12); st(1,
+	   if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0)); r(1-ld(1)) +
+	   b(ld(1))".
+
+       axisfile
+	   Specify image file to draw the axis. This option override fontfile
+	   and fontcolor option.
+
+       axis, text
+	   Enable/disable drawing text to the axis. If it is set to 0, drawing
+	   to the axis is disabled, ignoring fontfile and axisfile option.
+	   Default value is 1.
+
+       csp Set colorspace. The accepted values are:
+
+	   unspecified
+	       Unspecified (default)
+
+	   bt709
+	       BT.709
+
+	   fcc FCC
+
+	   bt470bg
+	       BT.470BG or BT.601-6 625
+
+	   smpte170m
+	       SMPTE-170M or BT.601-6 525
+
+	   smpte240m
+	       SMPTE-240M
+
+	   bt2020ncl
+	       BT.2020 with non-constant luminance
+
+       cscheme
+	   Set spectrogram color scheme. This is list of floating point values
+	   with format "left_r|left_g|left_b|right_r|right_g|right_b".	The
+	   default is "1|0.5|0|0|0.5|1".
+
+       Examples
+
+       o   Playing audio while showing the spectrum:
+
+		   ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
+
+       o   Same as above, but with frame rate 30 fps:
+
+		   ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
+
+       o   Playing at 1280x720:
+
+		   ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=s=1280x720:count=4 [out0]'
+
+       o   Disable sonogram display:
+
+		   sono_h=0
+
+       o   A1 and its harmonics: A1, A2, (near)E3, A3:
+
+		   ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
+				    asplit[a][out1]; [a] showcqt [out0]'
+
+       o   Same as above, but with more accuracy in frequency domain:
+
+		   ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
+				    asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
+
+       o   Custom volume:
+
+		   bar_v=10:sono_v=bar_v*a_weighting(f)
+
+       o   Custom gamma, now spectrum is linear to the amplitude.
+
+		   bar_g=2:sono_g=2
+
+       o   Custom tlength equation:
+
+		   tc=0.33:tlength='st(0,0.17); 384*tc / (384 / ld(0) + tc*f /(1-ld(0))) + 384*tc / (tc*f / ld(0) + 384 /(1-ld(0)))'
+
+       o   Custom fontcolor and fontfile, C-note is colored green, others are
+	   colored blue:
+
+		   fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))':fontfile=myfont.ttf
+
+       o   Custom font using fontconfig:
+
+		   font='Courier New,Monospace,mono|bold'
+
+       o   Custom frequency range with custom axis using image file:
+
+		   axisfile=myaxis.png:basefreq=40:endfreq=10000
+
+   showcwt
+       Convert input audio to video output representing frequency spectrum
+       using Continuous Wavelet Transform and Morlet wavelet.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "640x512".
+
+       rate, r
+	   Set the output frame rate. Default value is 25.
+
+       scale
+	   Set the frequency scale used. Allowed values are:
+
+	   linear
+	   log2
+	   bark
+	   mel
+	   erbs
+
+	   Default value is "linear".
+
+       min Set the minimum frequency that will be used in output.  Default is
+	   20 Hz.
+
+       max Set the maximum frequency that will be used in output.  Default is
+	   20000 Hz. The real frequency upper limit depends on input audio's
+	   sample rate and such will be enforced on this value when it is set
+	   to value greater than Nyquist frequency.
+
+       logb
+	   Set the logarithmic basis for brightness strength when mapping
+	   calculated magnitude values to pixel values.  Allowed range is from
+	   0 to 1.  Default value is 0.0001.
+
+       deviation
+	   Set the frequency deviation.  Lower values than 1 are more
+	   frequency oriented, while higher values than 1 are more time
+	   oriented.  Allowed range is from 0 to 10.  Default value is 1.
+
+       pps Set the number of pixel output per each second in one row.  Allowed
+	   range is from 1 to 1024.  Default value is 64.
+
+       mode
+	   Set the output visual mode. Allowed values are:
+
+	   magnitude
+	       Show magnitude.
+
+	   phase
+	       Show only phase.
+
+	   magphase
+	       Show combination of magnitude and phase.  Magnitude is mapped
+	       to brightness and phase to color.
+
+	   channel
+	       Show unique color per channel magnitude.
+
+	   stereo
+	       Show unique color per stereo difference.
+
+	   Default value is "magnitude".
+
+       slide
+	   Set the output slide method. Allowed values are:
+
+	   replace
+	   scroll
+	   frame
+       direction
+	   Set the direction method for output slide method. Allowed values
+	   are:
+
+	   lr  Direction from left to right.
+
+	   rl  Direction from right to left.
+
+	   ud  Direction from up to down.
+
+	   du  Direction from down to up.
+
+   showfreqs
+       Convert input audio to video output representing the audio power
+       spectrum.  Audio amplitude is on Y-axis while frequency is on X-axis.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify size of video. For the syntax of this option, check the
+	   "Video size" section in the ffmpeg-utils manual.  Default is
+	   "1024x512".
+
+       rate, r
+	   Set video rate. Default is 25.
+
+       mode
+	   Set display mode.  This set how each frequency bin will be
+	   represented.
+
+	   It accepts the following values:
+
+	   line
+	   bar
+	   dot
+
+	   Default is "bar".
+
+       ascale
+	   Set amplitude scale.
+
+	   It accepts the following values:
+
+	   lin Linear scale.
+
+	   sqrt
+	       Square root scale.
+
+	   cbrt
+	       Cubic root scale.
+
+	   log Logarithmic scale.
+
+	   Default is "log".
+
+       fscale
+	   Set frequency scale.
+
+	   It accepts the following values:
+
+	   lin Linear scale.
+
+	   log Logarithmic scale.
+
+	   rlog
+	       Reverse logarithmic scale.
+
+	   Default is "lin".
+
+       win_size
+	   Set window size. Allowed range is from 16 to 65536.
+
+	   Default is 2048
+
+       win_func
+	   Set windowing function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default is "hanning".
+
+       overlap
+	   Set window overlap. In range "[0, 1]". Default is 1, which means
+	   optimal overlap for selected window function will be picked.
+
+       averaging
+	   Set time averaging. Setting this to 0 will display current maximal
+	   peaks.  Default is 1, which means time averaging is disabled.
+
+       colors
+	   Specify list of colors separated by space or by '|' which will be
+	   used to draw channel frequencies. Unrecognized or missing colors
+	   will be replaced by white color.
+
+       cmode
+	   Set channel display mode.
+
+	   It accepts the following values:
+
+	   combined
+	   separate
+
+	   Default is "combined".
+
+       minamp
+	   Set minimum amplitude used in "log" amplitude scaler.
+
+       data
+	   Set data display mode.
+
+	   It accepts the following values:
+
+	   magnitude
+	   phase
+	   delay
+
+	   Default is "magnitude".
+
+       channels
+	   Set channels to use when processing audio. By default all are
+	   processed.
+
+   showspatial
+       Convert stereo input audio to a video output, representing the spatial
+       relationship between two channels.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "512x512".
+
+       win_size
+	   Set window size. Allowed range is from 1024 to 65536. Default size
+	   is 4096.
+
+       win_func
+	   Set window function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hann
+	   hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default value is "hann".
+
+       rate, r
+	   Set output framerate.
+
+   showspectrum
+       Convert input audio to a video output, representing the audio frequency
+       spectrum.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "640x512".
+
+       slide
+	   Specify how the spectrum should slide along the window.
+
+	   It accepts the following values:
+
+	   replace
+	       the samples start again on the left when they reach the right
+
+	   scroll
+	       the samples scroll from right to left
+
+	   fullframe
+	       frames are only produced when the samples reach the right
+
+	   rscroll
+	       the samples scroll from left to right
+
+	   lreplace
+	       the samples start again on the right when they reach the left
+
+	   Default value is "replace".
+
+       mode
+	   Specify display mode.
+
+	   It accepts the following values:
+
+	   combined
+	       all channels are displayed in the same row
+
+	   separate
+	       all channels are displayed in separate rows
+
+	   Default value is combined.
+
+       color
+	   Specify display color mode.
+
+	   It accepts the following values:
+
+	   channel
+	       each channel is displayed in a separate color
+
+	   intensity
+	       each channel is displayed using the same color scheme
+
+	   rainbow
+	       each channel is displayed using the rainbow color scheme
+
+	   moreland
+	       each channel is displayed using the moreland color scheme
+
+	   nebulae
+	       each channel is displayed using the nebulae color scheme
+
+	   fire
+	       each channel is displayed using the fire color scheme
+
+	   fiery
+	       each channel is displayed using the fiery color scheme
+
+	   fruit
+	       each channel is displayed using the fruit color scheme
+
+	   cool
+	       each channel is displayed using the cool color scheme
+
+	   magma
+	       each channel is displayed using the magma color scheme
+
+	   green
+	       each channel is displayed using the green color scheme
+
+	   viridis
+	       each channel is displayed using the viridis color scheme
+
+	   plasma
+	       each channel is displayed using the plasma color scheme
+
+	   cividis
+	       each channel is displayed using the cividis color scheme
+
+	   terrain
+	       each channel is displayed using the terrain color scheme
+
+	   Default value is channel.
+
+       scale
+	   Specify scale used for calculating intensity color values.
+
+	   It accepts the following values:
+
+	   lin linear
+
+	   sqrt
+	       square root, default
+
+	   cbrt
+	       cubic root
+
+	   log logarithmic
+
+	   4thrt
+	       4th root
+
+	   5thrt
+	       5th root
+
+	   Default value is sqrt.
+
+       fscale
+	   Specify frequency scale.
+
+	   It accepts the following values:
+
+	   lin linear
+
+	   log logarithmic
+
+	   Default value is lin.
+
+       saturation
+	   Set saturation modifier for displayed colors. Negative values
+	   provide alternative color scheme. 0 is no saturation at all.
+	   Saturation must be in [-10.0, 10.0] range.  Default value is 1.
+
+       win_func
+	   Set window function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hann
+	   hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default value is "hann".
+
+       orientation
+	   Set orientation of time vs frequency axis. Can be "vertical" or
+	   "horizontal". Default is "vertical".
+
+       overlap
+	   Set ratio of overlap window. Default value is 0.  When value is 1
+	   overlap is set to recommended size for specific window function
+	   currently used.
+
+       gain
+	   Set scale gain for calculating intensity color values.  Default
+	   value is 1.
+
+       data
+	   Set which data to display. Can be "magnitude", default or "phase",
+	   or unwrapped phase: "uphase".
+
+       rotation
+	   Set color rotation, must be in [-1.0, 1.0] range.  Default value is
+	   0.
+
+       start
+	   Set start frequency from which to display spectrogram. Default is
+	   0.
+
+       stop
+	   Set stop frequency to which to display spectrogram. Default is 0.
+
+       fps Set upper frame rate limit. Default is "auto", unlimited.
+
+       legend
+	   Draw time and frequency axes and legends. Default is disabled.
+
+       drange
+	   Set dynamic range used to calculate intensity color values. Default
+	   is 120 dBFS.  Allowed range is from 10 to 200.
+
+       limit
+	   Set upper limit of input audio samples volume in dBFS. Default is 0
+	   dBFS.  Allowed range is from -100 to 100.
+
+       opacity
+	   Set opacity strength when using pixel format output with alpha
+	   component.
+
+       The usage is very similar to the showwaves filter; see the examples in
+       that section.
+
+       Examples
+
+       o   Large window with logarithmic color scaling:
+
+		   showspectrum=s=1280x480:scale=log
+
+       o   Complete example for a colored and sliding spectrum per channel
+	   using ffplay:
+
+		   ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
+				[a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
+
+   showspectrumpic
+       Convert input audio to a single video frame, representing the audio
+       frequency spectrum.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "4096x2048".
+
+       mode
+	   Specify display mode.
+
+	   It accepts the following values:
+
+	   combined
+	       all channels are displayed in the same row
+
+	   separate
+	       all channels are displayed in separate rows
+
+	   Default value is combined.
+
+       color
+	   Specify display color mode.
+
+	   It accepts the following values:
+
+	   channel
+	       each channel is displayed in a separate color
+
+	   intensity
+	       each channel is displayed using the same color scheme
+
+	   rainbow
+	       each channel is displayed using the rainbow color scheme
+
+	   moreland
+	       each channel is displayed using the moreland color scheme
+
+	   nebulae
+	       each channel is displayed using the nebulae color scheme
+
+	   fire
+	       each channel is displayed using the fire color scheme
+
+	   fiery
+	       each channel is displayed using the fiery color scheme
+
+	   fruit
+	       each channel is displayed using the fruit color scheme
+
+	   cool
+	       each channel is displayed using the cool color scheme
+
+	   magma
+	       each channel is displayed using the magma color scheme
+
+	   green
+	       each channel is displayed using the green color scheme
+
+	   viridis
+	       each channel is displayed using the viridis color scheme
+
+	   plasma
+	       each channel is displayed using the plasma color scheme
+
+	   cividis
+	       each channel is displayed using the cividis color scheme
+
+	   terrain
+	       each channel is displayed using the terrain color scheme
+
+	   Default value is intensity.
+
+       scale
+	   Specify scale used for calculating intensity color values.
+
+	   It accepts the following values:
+
+	   lin linear
+
+	   sqrt
+	       square root, default
+
+	   cbrt
+	       cubic root
+
+	   log logarithmic
+
+	   4thrt
+	       4th root
+
+	   5thrt
+	       5th root
+
+	   Default value is log.
+
+       fscale
+	   Specify frequency scale.
+
+	   It accepts the following values:
+
+	   lin linear
+
+	   log logarithmic
+
+	   Default value is lin.
+
+       saturation
+	   Set saturation modifier for displayed colors. Negative values
+	   provide alternative color scheme. 0 is no saturation at all.
+	   Saturation must be in [-10.0, 10.0] range.  Default value is 1.
+
+       win_func
+	   Set window function.
+
+	   It accepts the following values:
+
+	   rect
+	   bartlett
+	   hann
+	   hanning
+	   hamming
+	   blackman
+	   welch
+	   flattop
+	   bharris
+	   bnuttall
+	   bhann
+	   sine
+	   nuttall
+	   lanczos
+	   gauss
+	   tukey
+	   dolph
+	   cauchy
+	   parzen
+	   poisson
+	   bohman
+	   kaiser
+
+	   Default value is "hann".
+
+       orientation
+	   Set orientation of time vs frequency axis. Can be "vertical" or
+	   "horizontal". Default is "vertical".
+
+       gain
+	   Set scale gain for calculating intensity color values.  Default
+	   value is 1.
+
+       legend
+	   Draw time and frequency axes and legends. Default is enabled.
+
+       rotation
+	   Set color rotation, must be in [-1.0, 1.0] range.  Default value is
+	   0.
+
+       start
+	   Set start frequency from which to display spectrogram. Default is
+	   0.
+
+       stop
+	   Set stop frequency to which to display spectrogram. Default is 0.
+
+       drange
+	   Set dynamic range used to calculate intensity color values. Default
+	   is 120 dBFS.  Allowed range is from 10 to 200.
+
+       limit
+	   Set upper limit of input audio samples volume in dBFS. Default is 0
+	   dBFS.  Allowed range is from -100 to 100.
+
+       opacity
+	   Set opacity strength when using pixel format output with alpha
+	   component.
+
+       Examples
+
+       o   Extract an audio spectrogram of a whole audio track in a 1024x1024
+	   picture using ffmpeg:
+
+		   ffmpeg -i audio.flac -lavfi showspectrumpic=s=1024x1024 spectrogram.png
+
+   showvolume
+       Convert input audio volume to a video output.
+
+       The filter accepts the following options:
+
+       rate, r
+	   Set video rate.
+
+       b   Set border width, allowed range is [0, 5]. Default is 1.
+
+       w   Set channel width, allowed range is [80, 8192]. Default is 400.
+
+       h   Set channel height, allowed range is [1, 900]. Default is 20.
+
+       f   Set fade, allowed range is [0, 1]. Default is 0.95.
+
+       c   Set volume color expression.
+
+	   The expression can use the following variables:
+
+	   VOLUME
+	       Current max volume of channel in dB.
+
+	   PEAK
+	       Current peak.
+
+	   CHANNEL
+	       Current channel number, starting from 0.
+
+       t   If set, displays channel names. Default is enabled.
+
+       v   If set, displays volume values. Default is enabled.
+
+       o   Set orientation, can be horizontal: "h" or vertical: "v", default
+	   is "h".
+
+       s   Set step size, allowed range is [0, 5]. Default is 0, which means
+	   step is disabled.
+
+       p   Set background opacity, allowed range is [0, 1]. Default is 0.
+
+       m   Set metering mode, can be peak: "p" or rms: "r", default is "p".
+
+       ds  Set display scale, can be linear: "lin" or log: "log", default is
+	   "lin".
+
+       dm  In second.  If set to > 0., display a line for the max level in the
+	   previous seconds.  default is disabled: 0.
+
+       dmc The color of the max line. Use when "dm" option is set to > 0.
+	   default is: "orange"
+
+   showwaves
+       Convert input audio to a video output, representing the samples waves.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "600x240".
+
+       mode
+	   Set display mode.
+
+	   Available values are:
+
+	   point
+	       Draw a point for each sample.
+
+	   line
+	       Draw a vertical line for each sample.
+
+	   p2p Draw a point for each sample and a line between them.
+
+	   cline
+	       Draw a centered vertical line for each sample.
+
+	   Default value is "point".
+
+       n   Set the number of samples which are printed on the same column. A
+	   larger value will decrease the frame rate. Must be a positive
+	   integer. This option can be set only if the value for rate is not
+	   explicitly specified.
+
+       rate, r
+	   Set the (approximate) output frame rate. This is done by setting
+	   the option n. Default value is "25".
+
+       split_channels
+	   Set if channels should be drawn separately or overlap. Default
+	   value is 0.
+
+       colors
+	   Set colors separated by '|' which are going to be used for drawing
+	   of each channel.
+
+       scale
+	   Set amplitude scale.
+
+	   Available values are:
+
+	   lin Linear.
+
+	   log Logarithmic.
+
+	   sqrt
+	       Square root.
+
+	   cbrt
+	       Cubic root.
+
+	   Default is linear.
+
+       draw
+	   Set the draw mode. This is mostly useful to set for high n.
+
+	   Available values are:
+
+	   scale
+	       Scale pixel values for each drawn sample.
+
+	   full
+	       Draw every sample directly.
+
+	   Default value is "scale".
+
+       Examples
+
+       o   Output the input file audio and the corresponding video
+	   representation at the same time:
+
+		   amovie=a.mp3,asplit[out0],showwaves[out1]
+
+       o   Create a synthetic signal and show it with showwaves, forcing a
+	   frame rate of 30 frames per second:
+
+		   aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
+
+   showwavespic
+       Convert input audio to a single video frame, representing the samples
+       waves.
+
+       The filter accepts the following options:
+
+       size, s
+	   Specify the video size for the output. For the syntax of this
+	   option, check the "Video size" section in the ffmpeg-utils manual.
+	   Default value is "600x240".
+
+       split_channels
+	   Set if channels should be drawn separately or overlap. Default
+	   value is 0.
+
+       colors
+	   Set colors separated by '|' which are going to be used for drawing
+	   of each channel.
+
+       scale
+	   Set amplitude scale.
+
+	   Available values are:
+
+	   lin Linear.
+
+	   log Logarithmic.
+
+	   sqrt
+	       Square root.
+
+	   cbrt
+	       Cubic root.
+
+	   Default is linear.
+
+       draw
+	   Set the draw mode.
+
+	   Available values are:
+
+	   scale
+	       Scale pixel values for each drawn sample.
+
+	   full
+	       Draw every sample directly.
+
+	   Default value is "scale".
+
+       filter
+	   Set the filter mode.
+
+	   Available values are:
+
+	   average
+	       Use average samples values for each drawn sample.
+
+	   peak
+	       Use peak samples values for each drawn sample.
+
+	   Default value is "average".
+
+       Examples
+
+       o   Extract a channel split representation of the wave form of a whole
+	   audio track in a 1024x800 picture using ffmpeg:
+
+		   ffmpeg -i audio.flac -lavfi showwavespic=split_channels=1:s=1024x800 waveform.png
+
+   sidedata, asidedata
+       Delete frame side data, or select frames based on it.
+
+       This filter accepts the following options:
+
+       mode
+	   Set mode of operation of the filter.
+
+	   Can be one of the following:
+
+	   select
+	       Select every frame with side data of "type".
+
+	   delete
+	       Delete side data of "type". If "type" is not set, delete all
+	       side data in the frame.
+
+       type
+	   Set side data type used with all modes. Must be set for "select"
+	   mode. For the list of frame side data types, refer to the
+	   "AVFrameSideDataType" enum in libavutil/frame.h. For example, to
+	   choose "AV_FRAME_DATA_PANSCAN" side data, you must specify
+	   "PANSCAN".
+
+   spectrumsynth
+       Synthesize audio from 2 input video spectrums, first input stream
+       represents magnitude across time and second represents phase across
+       time.  The filter will transform from frequency domain as displayed in
+       videos back to time domain as presented in audio output.
+
+       This filter is primarily created for reversing processed showspectrum
+       filter outputs, but can synthesize sound from other spectrograms too.
+       But in such case results are going to be poor if the phase data is not
+       available, because in such cases phase data need to be recreated,
+       usually it's just recreated from random noise.  For best results use
+       gray only output ("channel" color mode in showspectrum filter) and
+       "log" scale for magnitude video and "lin" scale for phase video. To
+       produce phase, for 2nd video, use "data" option. Inputs videos should
+       generally use "fullframe" slide mode as that saves resources needed for
+       decoding video.
+
+       The filter accepts the following options:
+
+       sample_rate
+	   Specify sample rate of output audio, the sample rate of audio from
+	   which spectrum was generated may differ.
+
+       channels
+	   Set number of channels represented in input video spectrums.
+
+       scale
+	   Set scale which was used when generating magnitude input spectrum.
+	   Can be "lin" or "log". Default is "log".
+
+       slide
+	   Set slide which was used when generating inputs spectrums.  Can be
+	   "replace", "scroll", "fullframe" or "rscroll".  Default is
+	   "fullframe".
+
+       win_func
+	   Set window function used for resynthesis.
+
+       overlap
+	   Set window overlap. In range "[0, 1]". Default is 1, which means
+	   optimal overlap for selected window function will be picked.
+
+       orientation
+	   Set orientation of input videos. Can be "vertical" or "horizontal".
+	   Default is "vertical".
+
+       Examples
+
+       o   First create magnitude and phase videos from audio, assuming audio
+	   is stereo with 44100 sample rate, then resynthesize videos back to
+	   audio with spectrumsynth:
+
+		   ffmpeg -i input.flac -lavfi showspectrum=mode=separate:scale=log:overlap=0.875:color=channel:slide=fullframe:data=magnitude -an -c:v rawvideo magnitude.nut
+		   ffmpeg -i input.flac -lavfi showspectrum=mode=separate:scale=lin:overlap=0.875:color=channel:slide=fullframe:data=phase -an -c:v rawvideo phase.nut
+		   ffmpeg -i magnitude.nut -i phase.nut -lavfi spectrumsynth=channels=2:sample_rate=44100:win_func=hann:overlap=0.875:slide=fullframe output.flac
+
+   split, asplit
+       Split input into several identical outputs.
+
+       "asplit" works with audio input, "split" with video.
+
+       The filter accepts a single parameter which specifies the number of
+       outputs. If unspecified, it defaults to 2.
+
+       Examples
+
+       o   Create two separate outputs from the same input:
+
+		   [in] split [out0][out1]
+
+       o   To create 3 or more outputs, you need to specify the number of
+	   outputs, like in:
+
+		   [in] asplit=3 [out0][out1][out2]
+
+       o   Create two separate outputs from the same input, one cropped and
+	   one padded:
+
+		   [in] split [splitout1][splitout2];
+		   [splitout1] crop=100:100:0:0    [cropout];
+		   [splitout2] pad=200:200:100:100 [padout];
+
+       o   Create 5 copies of the input audio with ffmpeg:
+
+		   ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
+
+   zmq, azmq
+       Receive commands sent through a libzmq client, and forward them to
+       filters in the filtergraph.
+
+       "zmq" and "azmq" work as a pass-through filters. "zmq" must be inserted
+       between two video filters, "azmq" between two audio filters. Both are
+       capable to send messages to any filter type.
+
+       To enable these filters you need to install the libzmq library and
+       headers and configure FFmpeg with "--enable-libzmq".
+
+       For more information about libzmq see: <http://www.zeromq.org/>
+
+       The "zmq" and "azmq" filters work as a libzmq server, which receives
+       messages sent through a network interface defined by the bind_address
+       (or the abbreviation "b") option.  Default value of this option is
+       tcp://localhost:5555. You may want to alter this value to your needs,
+       but do not forget to escape any ':' signs (see filtergraph escaping).
+
+       The received message must be in the form:
+
+	       <TARGET> <COMMAND> [<ARG>]
+
+       TARGET specifies the target of the command, usually the name of the
+       filter class or a specific filter instance name. The default filter
+       instance name uses the pattern Parsed_<filter_name>_<index>, but you
+       can override this by using the filter_name@id syntax (see Filtergraph
+       syntax).
+
+       COMMAND specifies the name of the command for the target filter.
+
+       ARG is optional and specifies the optional argument list for the given
+       COMMAND.
+
+       Upon reception, the message is processed and the corresponding command
+       is injected into the filtergraph. Depending on the result, the filter
+       will send a reply to the client, adopting the format:
+
+	       <ERROR_CODE> <ERROR_REASON>
+	       <MESSAGE>
+
+       MESSAGE is optional.
+
+       Examples
+
+       Look at tools/zmqsend for an example of a zmq client which can be used
+       to send commands processed by these filters.
+
+       Consider the following filtergraph generated by ffplay.	In this
+       example the last overlay filter has an instance name. All other filters
+       will have default instance names.
+
+	       ffplay -dumpgraph 1 -f lavfi "
+	       color=s=100x100:c=red  [l];
+	       color=s=100x100:c=blue [r];
+	       nullsrc=s=200x100, zmq [bg];
+	       [bg][l]	 overlay     [bg+l];
+	       [bg+l][r] overlay@my=x=100 "
+
+       To change the color of the left side of the video, the following
+       command can be used:
+
+	       echo Parsed_color_0 c yellow | tools/zmqsend
+
+       To change the right side:
+
+	       echo Parsed_color_1 c pink | tools/zmqsend
+
+       To change the position of the right side:
+
+	       echo overlay@my x 150 | tools/zmqsend
+
+MULTIMEDIA SOURCES
+       Below is a description of the currently available multimedia sources.
+
+   amovie
+       This is the same as movie source, except it selects an audio stream by
+       default.
+
+   avsynctest
+       Generate an Audio/Video Sync Test.
+
+       Generated stream periodically shows flash video frame and emits beep in
+       audio.  Useful to inspect A/V sync issues.
+
+       It accepts the following options:
+
+       size, s
+	   Set output video size. Default value is "hd720".
+
+       framerate, fr
+	   Set output video frame rate. Default value is 30.
+
+       samplerate, sr
+	   Set output audio sample rate. Default value is 44100.
+
+       amplitude, a
+	   Set output audio beep amplitude. Default value is 0.7.
+
+       period, p
+	   Set output audio beep period in seconds. Default value is 3.
+
+       delay, dl
+	   Set output video flash delay in number of frames. Default value is
+	   0.
+
+       cycle, c
+	   Enable cycling of video delays, by default is disabled.
+
+       duration, d
+	   Set stream output duration. By default duration is unlimited.
+
+       fg, bg, ag
+	   Set foreground/background/additional color.
+
+   movie
+       Read audio and/or video stream(s) from a movie container.
+
+       It accepts the following parameters:
+
+       filename
+	   The name of the resource to read (not necessarily a file; it can
+	   also be a device or a stream accessed through some protocol).
+
+       format_name, f
+	   Specifies the format assumed for the movie to read, and can be
+	   either the name of a container or an input device. If not
+	   specified, the format is guessed from movie_name or by probing.
+
+       seek_point, sp
+	   Specifies the seek point in seconds. The frames will be output
+	   starting from this seek point. The parameter is evaluated with
+	   "av_strtod", so the numerical value may be suffixed by an IS
+	   postfix. The default value is "0".
+
+       streams, s
+	   Specifies the streams to read. Several streams can be specified,
+	   separated by "+". The source will then have as many outputs, in the
+	   same order. The syntax is explained in the "Stream specifiers"
+	   section in the ffmpeg manual. Two special names, "dv" and "da"
+	   specify respectively the default (best suited) video and audio
+	   stream. Default is "dv", or "da" if the filter is called as
+	   "amovie".
+
+       stream_index, si
+	   Specifies the index of the video stream to read. If the value is
+	   -1, the most suitable video stream will be automatically selected.
+	   The default value is "-1". Deprecated. If the filter is called
+	   "amovie", it will select audio instead of video.
+
+       loop
+	   Specifies how many times to read the stream in sequence.  If the
+	   value is 0, the stream will be looped infinitely.  Default value is
+	   "1".
+
+	   Note that when the movie is looped the source timestamps are not
+	   changed, so it will generate non monotonically increasing
+	   timestamps.
+
+       discontinuity
+	   Specifies the time difference between frames above which the point
+	   is considered a timestamp discontinuity which is removed by
+	   adjusting the later timestamps.
+
+       dec_threads
+	   Specifies the number of threads for decoding
+
+       format_opts
+	   Specify format options for the opened file. Format options can be
+	   specified as a list of key=value pairs separated by ':'. The
+	   following example shows how to add protocol_whitelist and
+	   protocol_blacklist options:
+
+		   ffplay -f lavfi
+		   "movie=filename='1.sdp':format_opts='protocol_whitelist=file,rtp,udp\:protocol_blacklist=http'"
+
+       It allows overlaying a second video on top of the main input of a
+       filtergraph, as shown in this graph:
+
+	       input -----------> deltapts0 --> overlay --> output
+						   ^
+						   |
+	       movie --> scale--> deltapts1 -------+
+
+       Examples
+
+       o   Skip 3.2 seconds from the start of the AVI file in.avi, and overlay
+	   it on top of the input labelled "in":
+
+		   movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
+		   [in] setpts=PTS-STARTPTS [main];
+		   [main][over] overlay=16:16 [out]
+
+       o   Read from a video4linux2 device, and overlay it on top of the input
+	   labelled "in":
+
+		   movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
+		   [in] setpts=PTS-STARTPTS [main];
+		   [main][over] overlay=16:16 [out]
+
+       o   Read the first video stream and the audio stream with id 0x81 from
+	   dvd.vob; the video is connected to the pad named "video" and the
+	   audio is connected to the pad named "audio":
+
+		   movie=dvd.vob:s=v:0+#0x81 [video] [audio]
+
+       Commands
+
+       Both movie and amovie support the following commands:
+
+       seek
+	   Perform seek using "av_seek_frame".	The syntax is: seek
+	   stream_index|timestamp|flags
+
+	   o   stream_index: If stream_index is -1, a default stream is
+	       selected, and timestamp is automatically converted from
+	       AV_TIME_BASE units to the stream specific time_base.
+
+	   o   timestamp: Timestamp in AVStream.time_base units or, if no
+	       stream is specified, in AV_TIME_BASE units.
+
+	   o   flags: Flags which select direction and seeking mode.
+
+       get_duration
+	   Get movie duration in AV_TIME_BASE units.
+
+SEE ALSO
+       ffmpeg(1), ffplay(1), ffprobe(1), libavfilter(3)
+
+AUTHORS
+       The FFmpeg developers.
+
+       For details about the authorship, see the Git history of the project
+       (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in
+       the FFmpeg source directory, or browsing the online repository at
+       <http://source.ffmpeg.org>.
+
+       Maintainers for the specific components are listed in the file
+       MAINTAINERS in the source code tree.
+
+							     FFMPEG-FILTERS(1)