[FFmpeg-soc] [PATCH] xiph packetizer

[Luca Barbato]

On 07/27/2010 12:03 PM, Martin Storsjö wrote:
> +    /* set ident
> +     * Probably need a non-fixed way of generating
> +     * this, but it has to be done in SDP and passed in from there. */
> +    q = s->buf;
> +    *q++ = 0xfe;
> +    *q++ = 0xcd;
> +    *q++ = 0xba;
> 
> I haven't read the specs, but what's the role of this ident code? Is there 
> any harm in having it hardcoded to a specific value? Is it set in the 
> original stream data somewhere, so that you'd have to parse out the 
> correct value from there? Or is it only used to distinguish streams if you 
> have more than one vorbis/theora stream in the same presentation? In that 
> case, you could use e.g. one hardcoded value for vorbis and another for 
> theora - that would probably be enough for some time at lesat.

given that we don't have any way to change the extradata and it is
needed just to make sure the packets we are receiving haven't changed
the extradata is some way. That had been mandated by loud people wanting
to support chained vorbis the same way they did in ogg iirc, we can
safely hardcode it.

lu

-- 

Luca Barbato
Gentoo/linux
http://dev.gentoo.org/~lu_zero