[FFmpeg-devel] [RFC] stream parsing

Benjamin Larsson banan
Sat Sep 25 17:01:28 CEST 2010

>> Yeah the issue is that some codecs don't know the channel count thus you
>> need the info from the container and sometimes the codec has better
>> knowledge which could possibly be different from the container (and is
>> for the 2 files in issue 2137).
>> So
>> /**
>>  * Codec know the channel configuration better then the container
>>  */
>> #define CODEC_CAP_CHANNEL_CONF    0x0100
>> And something in av_find_stream_info that checks that flag ?
> I don't think there's a point since it fixes at most half the issue.
> For those formats where this can happen, it is also possible
> that the channel count changes in the middle.
> If that cases is handled correctly, this automatically becomes
> a non-issue (and the container value could mean "better upmix
> even if it is stereo now, because it will have 5 channels later").

Well the issue is that the container reports something that doesn't
correlate with the stream contained in the container. It has nothing to
do with midstream channel configuration changes. What you describe is
another kind of possible problem.

Benjamin Larsson

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