[Ffmpeg-devel] Re: Re: Re: [theora-dev] Theora encoding in FFmpeg

Rich Felker dalias
Mon Jan 1 01:16:35 CET 2007

On Sun, Dec 31, 2006 at 08:09:54PM +0000, Paul Richards wrote:
> On 31/12/06, Michael Niedermayer <michaelni at gmx.at> wrote:
> >On Sun, Dec 31, 2006 at 05:56:11PM +0000, Paul Richards wrote:
> >> And on a deeper level..
> >>
> >> Why is all this special packing of the output from theora_encode_***()
> >> into the extradata required?  I naively assumed that any packing like
> >> this would be the responsibility of the muxer...
> >
> >no of course not, just think about this for a moment, should the avi muxer
> >contain code to repackage theora, vorbis, ... headers? then what about
> >matroska, nut, asf, mov, mp4, ... ? should every muxer contain (duplicated)
> >code to pack all the codec specific xiph headers into a single packet?
> >
> >and then after you duplicated that code in every muxer, you will have to
> >add code to every corresponding demuxer to undo it otherwise you cannot
> >copy a stream between 2 containers witout reencoding ...
> >
> >simply putting the (de)packaging code into the 2 or 3 xiph codecs is much
> >easier ...
> >
> In that case shouldn't there be a function in libtheora to concatenate
> all of the "extradata" packets together in a container-insensitive
> way?

yes, there certainly should be. unfortunately the xiph people, in
their infinite wisdom, are outwardly hostile to container-insensitive
things and want to make their codecs as painful as possible to use
with non-ogg containers.

btw, is there a reason you want to use theora so much? it's not a good
codec at all..


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