Based on the volume filter in FFmpeg written by Stefano Sabatini
<stefasab@gmail.com>.

This filter modifies the input frame.

Any alleged performance benefits gained from the split are purely
mythological and do not justify added code complexity.

The following commit will make it useless.

The crop_scale_vflip FATE test changes because of off-by-one differences
in output when vflipped slices are passed to sws.

Also reorder some other #include when applicable.

This is more consistent with the way we handle C #includes and
it simplifies the build system.

This is necessary to allow refactoring some x86util macros with cpuflags.

It can be useful for debugging.

Based on a patch by Stefano Sabatini <stefano.sabatini-lala@poste.it>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Fixes CID700635, CID700636 and CID732274.

A number of compilers, for example those from TI and IBM, choke on
these initialisers.  The current style is also quite ugly.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Does not make a difference in this case since sizeof(uint8_t*) ==
sizeof(uint8_t**). Fixes CID703814.

Fixes CID732273.

Fixes CID732272.

Prevents writes to freed memory and the leak of the old extended data.
Fixes CID732303.

When there is only 1 channel, the planar and interleaved formats of the same
data type should be treated as identical.

Anonymous structs cannot be forward declared and have no benefit.

Fixes Bug 203.

CC:libav-stable@libav.org

This is more consistent with what the rest of Libav does.

This breaks API.

Right now it incorrectly assumes that the frames are sent in the proper
order, which worked with old ffmpeg and avconv versions by accident.

Output frames correspond 1:1 to input frames on the main input.
So use the main input timebase for output.

The warning is:
libavfilter/avfiltergraph.c: In function ‘avfilter_graph_config’:
libavfilter/avfiltergraph.c:528:9: warning: ‘best_idx’ may be used uninitialized in this function [-Wuninitialized]
libavfilter/avfiltergraph.c:479:13: note: ‘best_idx’ was declared here

Initialize it to an invalid value and add an assert that it's properly
set later.

Signed-off-by: Mans Rullgard <mans@mansr.com>

Fixes an infinite loop on flush when avresample_get_delay() still
reports some samples but avresample_convert() doesn't return any data.

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>