[Ffmpeg-devel] Native ogg demuxer

Måns Rullgård mru
Tue Apr 12 23:15:46 CEST 2005

matthieu castet <castet.matthieu at free.fr> writes:

> Hi,
> M?ns Rullg?rd wrote:
>> matthieu castet <castet.matthieu at free.fr> writes:
>>>Hi M?ns,
>>>M?ns Rullg?rd wrote:
>>>>matthieu castet <castet.matthieu at free.fr> writes:
>>>>>What's the point of doing external sub-plugin that use global
>>>>>variable instead of static variable and if conditions ?
>>>>Cleaner design, IMHO.
>>>Yes but you could have all the sub-plugin in the same file and make it
>>>static. This is more or less what do liboggz
>> I fail to see a significant difference.
> You couldn't use global var with the same name in the user application
> and there will be lot's of file for off in libavformat.

In tcvp, that's not a problem, since all those files are compiled into
a module that's dlopened with RTLD_LOCAL.  I'll add some prefix to the
names in libavformat.

>>>>>Also now the parsing of the extrada (comments, codec init, ...) is
>>>>>done twice : once in the demuxer, once in the decoder.
>>>>The codec does not, and should not, touch the comment section.
>>>Actually if you look theora implementation it read and skip and the comment.
>>>So you sugest to not put the comment in the codec extradata (2nd header
>>>in vorbis and theora) ?
>> Libvorbis requires the comment section, but doesn't actually use it
>> for anything.  (Yes, we all know it's stupid.)
> We could set an empty one (u32(0) u32(0) u1(1)).
> Yes that's really stupid

That won't do, it has to have some minimal content, or libvorbis gets
very upset.

> Matthieu
> PS : I attach a patch to support theora format.

I'll check it out, maybe even check it in.

M?ns Rullg?rd
mru at inprovide.com

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