vf_fade: use AVPixFmtDescriptor to find out if pixel format have alpha

Remove alpha_pix_fmts[].

Signed-off-by: Paul B Mahol <onemda@gmail.com>
lavf/utils: provide feedback in case of invalid probe size

Log message in case the max_probe_size value in av_probe_input_buffer()
is smaller than the minimum accepted value.
lavf/segment: add SegmentListEntry and use it

This patch is propedeutic to the incoming patch which adds
support to sliding window segment listing.
lavf/segment: add support to segment list file entries sliding window listing

In particular, should fix trac ticket #1842.
lavf/segment: remove now unused field list_max_segment_time
lavf/segment: move reference stream selection code to a dedicated function
lavf/segment: do not auto-select a video stream with attached_pic disposition

In particular, fix trac ticket #2138.
doc/muxers: apply minor cosmetics to segment option descriptions
sws: add AVOption flag for error diffusion dither

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
sws: rgb/bgr 4/8 error diffusion dither

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
sws: Only reset dither state for bitexact mode

the output looks better with a random initial state than
all 0

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
sws: Enable full chroma resolution when needed for ED dither

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>