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

[Svante Seleborg]

Thanks for the response!

(snip)
> 1 - Chaining a logical bistream at the end. If this is the way to go, two
>> questions arise to begin with:
>
>Probably not the way to go.

Ok...

>
>> q1a - How to identify this stream in a future-proof way? Just
>invent a new
>> header, beginning with 'm' 'y' 'h' 'e' 'a' 'd' 'e' 'r' ?
>
>'myheader' is a little bit too generic. You probably want to find a more
>descriptive name.

Of course - it was just a place-holder. The question was really - how should
I define that in a way to reduce risk of future collisions? Is there
somewhere
such names are registred, like mime-types? But then again - That was not
the way to go anyway...

>> 2 - Inserting non-audio packets in the actual stream. This situation is
(snip)
>Correct. This is a bad idea.

Thought so.

<p>>> 3 - Another choice, which for various reasons feel less satisfying, is to
>> encode it as comments. The problem with this is first of all that it may
(snip)

>Correct again. This is also a bad idea.
Thought so too.

>> 4 - Can I possibly just concatenate a completely separate Ogg stream at
>the
>> end of the first one? This seems to violate the constraints of an
>Ogg/Vorbis
>> I stream though.
>
>Sure. Multiple Ogg files can be chained by 'cat' (or the weird 'copy /b + '
>syntax on DOS/Windows). This is perfectly legal (and gapless).

That's what I was hoping for - now that you mention it I even recall
somewhere
that this is specifically mentioned as strictly ok. I'll check that further
then.

On the other hand I have another responder empathically stating this is not
a good idea... Hmm.

>You probably want to interleave your stream with audio, right? Take a look
>at the ogmtools, oggmux, oggmerge and similar. They mostly seem to be
>designed for a single purpose right now (audio+video+subtitles, or
>vorbis+midi), but it shouldn't be too dificult to modify one of
>the above to
>recognise your new custom stream.

No, I want the Ogg/Vorbis I file to carry other data without disturbing
existing players.

/Svante

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