isom: convert mp4 dvdsub extradata to vobsub format

mp4 files embedding DVD subtitles do not use the same extradata format
as the rest of Libav expects. The subtitle decoder in libavcodec in
particular does not understand this format.

Convert the extradata to the vobsub .idx format. mp4 stores the palette
as binary 32 bit ints in YUV. The subtitle resolution is stored
separately in the track header, which we access through AVStream.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
af_channelmap: fix ONE_STR mapping mode

get_channel() returns 0 on success

CC:libav-stable@libav.org
FATE: add a test for the ONE_STR mapping mode of the channelmap filter
aacdec: Don't count probed ADTS frames if there are false positives

If a portion of the probe buffer seem to resemble ADTS frames,
but some data at the end is a mismatch, disregard the whole
probing attempt. If it actually is ADTS data, there shouldn't be
any mismatches within the sequential frame data.

Signed-off-by: Martin Storsjö <martin@martin.st>
aacdec: Lower the number of frames required to detect ADTS

For live audio streams, requiring 500 frames for a stream to
be detected is a bit overkill.

This allows live ADTS streams that don't start nicely at
a frame boundary to start up more quickly, e.g.
http://mp3.streampower.be/radio1.aac.

Signed-off-by: Martin Storsjö <martin@martin.st>
mpegvideo: directly use frames in ff_draw_horiz_band()
h264: directly use frames in ff_h264_draw_horiz_band()
er: move relevant fields from Picture to ERPicture

This is done to disentangle ER from mpegvideo. In order to use a
classic Picture, callers can use ff_mpeg_set_erpic() or use a custom function
to set the fields. Please note that buffers need to be allocated before
calling ff_er_frame_end().
h264: move relevant fields from Picture to H264Picture
h264: Replace mpegvideo-specific MAX_PICTURE_COUNT by private define
h264: Replace mpegvideo-specific MAX_THREADS by private define
h264: Remove MotionEstContext and move the relevant fields to H264Context

Unused buffers scratchpad and temp have been dropped too.
mpegvideo: move mpegvideo formats-related defines to mpegutils.h
mpegvideo: move ff_draw_horiz_band() to mpegutils.c

Drop the mpegvideo dependency for svq3 in configure.
mpegvideo: remove h264-only fields
h264 does not depend on mpegvideo any more
RGBA64 pixel formats

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
isom: fix C99-style declaration
codec_desc: update dvaudio tag
png: K&R formatting cosmetics