[FFmpeg-devel] [PATCH] Function to parse Dirac sequence header

[David Conrad]

On Nov 9, 2008, at 4:29 AM, Michael Niedermayer wrote:

> On Wed, Nov 05, 2008 at 11:22:01PM -0500, David Conrad wrote:
>> Hi,
>>
>> This will be useful for both the dirac parser and ogg demuxer (and  
>> future
>> native dirac decoder of course.)
>> Adapted from the soc repository.
>
> I think the parser should not need this, av_find_stream_info()  
> should call
> the decoder to fill in missing information. That assumes there is a  
> decoder
> that does set it ...
>
> about the ogg demuxer iam not sure if its needed or not ...

The problem with ogg is that the only place the stream time_base is  
stored is in a codec-dependent way. Theora, FLAC, and Vorbis also have  
to parse their first setup packet to find this, the difference is that  
they don't use vlc and default tables so it's just simple reads at  
known offsets.

The decoder will set the time_base in AVCodecContext, but I'm not sure  
how the time_base in AVStream would get set correctly if the demuxer  
doesn't set it.