[Matroska-general] Re: OGM support for oggdemux

ChristianHJW christian at matroska.org
Sun Jul 11 22:27:45 CEST 2004


Ronald S. Bultje wrote:
> Hi,
> Sun, 2004-07-04 at 17:53, Benjamin Otte wrote:
>>I don't like that patch, for a simple reason: I intend oggdemux to stay agnostic
>>of the contents and get caps information and so on via typefinding and external
>>elements.
> 
> Is Ogg any different from OGM? As in, are the streams somewhat
> different? If so, you could make a separate ogmdemux element that is a
> subclass of oggdemux, and have that specifically handle OGM, while
> oggdemux keeps handling Ogg only.
> If not, I'm affraid we have no solution for this problem and I'm affraid
> we'll have to apply the patch anyway; I don't think you can typefind the
> OGM-supported codecs, can you...
> Ronald

I was recently talking to Jack Moffit, one of the founders and heads of 
Xiph, and their 'official' opinion about OGM is that they are trying to 
ignore it whenever they can, because it was made to contain 'non-free' 
codecs like MPEG4.

Jack has a very relaxed feeling about matroska, being a general purpose 
container, while he wants Ogg to be a transport layer for the Xiph 
codecs, and other free codecs. So, while OGM is in principal competing 
with matroska ( its basically what we call 'DirectShow compatibility 
mode' in MKV, but for Ogg ), Ogg itself is not, at least from his point 
of view, and i cant agree more.

Speaking of your demuxers, you should build them with that in mind, i.e. 
try to separate the OGM demuxer classes on top of the Ogg parser, so 
that future updates of the Ogg codebase dont require to rewrite OGM 
support, if this is possible at all.

just my 2 cents

Christian
matroska project admin
http://www.matroska.org



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