[vlc-devel] streaming ffmpeg's video

Laurent Aimar fenrir at via.ecp.fr
Mon Dec 8 18:54:16 CET 2008


On Mon, Dec 08, 2008, Rémi Denis-Courmont wrote:
> Le lundi 8 décembre 2008 17:17:39 Danny Wood, vous avez écrit :
> > There's quite a large list of the fourccs in the file
> > vlc/modules/codec/avcodec/fourcc.c
> > The first structure seems to do the mapping to ffmpeg id.
> 
> There are certain VLC FOURCC that are not included there. Ffmpeg does not 
> implement all of them.
> 
> > Search for fmp4 reveals:
> >
> >     { VLC_FOURCC('F','M','P','4'), CODEC_ID_MPEG4,
> >       VIDEO_ES, "MPEG-4 Video" },
> >     { VLC_FOURCC('f','m','p','4'), CODEC_ID_MPEG4,
> >       VIDEO_ES, "MPEG-4 Video" },
> >
> > Sorry if this info is irrelevant.
> 
> Yeah, but that does not tell me why we need different FOURCCs for these.
 They allow to identify which encoder produced the stream and so, it allows
to workaround specific implementation bug.
 That's why a lot of encoder use their own fourcc instead of a unique one.

 Now, the current situation is not really good because every time you have to know
the codec associated to a fourcc, you need to check for all implementation fourcc.

 I plan to have a centralized way to identify the real codec to avoid spreading
all over vlc code.

-- 
fenrir



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