[ogg-dev] How Ogg mappings translate into the codecs parameter in Ogg media types

Ralph Giles giles at xiph.org
Sat May 24 09:53:01 PDT 2008

On 24-May-08, at 9:26 AM, Ivo Emanuel Gonçalves wrote:

> I don't think that interferes with anything.  We are talking about  
> the essential part needed to be detected by applications.

Conrad was just saying that the way you described the ids was  
inconsistent. One column said read 8 chars, the other said compare  
with a string that might be less than eight characters.

> Dirac is the only one I'm not sure, since this one here's the  
> recent string.

It's supposed to be finalized though there many be some granulepos  
issues still in current implementations. I don't expect the BBCD\0  
magic to change.

OggMNG defines the following magics:

char[8]: "\211PNG\r\n\032\n" png
char[8]: "\212MNG\r\n\032\n" mng
char[8]: "\213JNG\r\n\032\n" jng

Are the 'Codecs Parameter' values from a different namespace from the  
media-types? Do we define a mapping where there is one, e.g. vorbis  
is audio/vorbis?

And there's OggY4M which uses char[9]: "YUV4MPEG2" but that's in no  
way finalized.


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