[xiph-rtp] about theora-over-rtp draft

[Rhys Hawkins]

On Fri, 21 Jul 2006 00:46:27 +0200
Luca Barbato <lu_zero at gentoo.org> wrote:
> > Finally, I would expect about this draft to tell how to split a big theora 
> > frame in several mtu-sized packets in a way that would make a partially 
> > received frame usable by the decoder. In other words, how to be as safe as 
> > possible in case of packet losses. But I don't know whether this is something 
> > possible, I don't know enough about the internals of theora.
> 
> The current draft expects a lost one - lost everything scenario.
> 

I said something similar a little while ago and I still think the theora spec 
should aim for greater fault tolerance. This may require consultation with the 
theora people to add the necessary hooks into their api to do partial frame 
decoding. But at the very least the rtp spec should recommend a robust way of 
breaking up the theora bitstream, like macroblocks in H261, or restart intervals 
in JPEG.

The "lost one - lost everything" approach will work on the local network, but
not over wide area multicast (for example), and I'm not interested in sending 
video to the computer next to me (and I'd be surprised if anybody was:) 

Cheers,
    Rhys