ffmpeg options: Enable trailing ? for map_channel
authorpkviet <pkv.stream@gmail.com>
Tue, 22 Aug 2017 09:30:45 +0000 (11:30 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Fri, 25 Aug 2017 21:41:11 +0000 (23:41 +0200)
commite0436ddaa49699fd3842ca36a9524bf31b55cfed
treeac7923c3e0b9b840e973b83b409f10c7d8e797d1
parent7c10068da10aa288195f5eb5d7e34eb2d8ff7447
ffmpeg options: Enable trailing ? for map_channel

The -map option allows for a trailing ? so that an error is not thrown if
the input stream does not exist.
This capability is extended to the map_channel option.
This allows a ffmpeg command not to break if an input channel does not
exist, which can be of use (for instance, scripts processing audio
channels with sources having unset number of audio channels).

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
doc/ffmpeg.texi
ffmpeg_opt.c
tests/fate/ffmpeg.mak
tests/ref/fate/mapchan-2ch-extract-ch0-ch2-trailing [new file with mode: 0644]
tests/ref/fate/mapchan-3ch-extract-ch0-ch2-trailing [new file with mode: 0644]