[vorbis-dev] Carrying non-audio data in an Ogg/Vorbis I stream

[Ralph Giles]

On Monday, October 28, 2002, at 08:46 PM, Svante Seleborg wrote:

> I did read it all... I might have missed something though, but I was
> under the impression that "Ogg/Vorbis I" specifically meant Vorbis
> encoded audio carried in an Ogg stream, under some very specific
> restrictions, the major one here being that multiplexing of the Ogg
> stream is not allowed - only chaining. See the "Restrictions" section
> of http://www.xiph.org/ogg/vorbis/doc/vorbis-ogg.html.
>
> The point of the excercise is to bring other data in there, without
> breaking this specification or violating these constraints.

Yes, unfortunately Monty wrote the spec this way. Obviously a vorbis 
decoder should just decode the first vorbis bitstream it finds in a 
multiplexed file, silently discarding any substream types it doesn't 
understand.

Nevertheless, multiplexing your data and the vorbis stream within the 
ogg file is the way to do this.

> That was what I meant, sorry if I was unclear. I meant using a 
> 'private'
> header for the chained logical bitstream. I assume you mean the 
> 'Theora'
> project when you say 'Theo' - but why should I contact them?

Not officially. Just pick something sane, and if it's popular you won't 
be the one who has to worry about conflicts. :)

You can add further redundancy checks to verify the packets are yours 
if you're worried.

FWIW,
  -r

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