[FFmpeg-devel] H.263 packetizing into RTP
Fri Apr 3 21:47:14 CEST 2009
On Fri, 2009-04-03 at 21:08 +0300, Martin Storsj? wrote:
> > > also i suspect that packets should be split at slices/gobs
> > RFC 2190 states that pictures should be split either at gob level
> > (mode A), at MB boundaries (mode B) or at MB boundaires of P-frames
> > with PB-frame mode.
> As far as I know (I found the original patch in a mailing list post from
> Luca Abeni), this is an implementation of RFC 4629 (and 2429); this is a
> different RTP packetization scheme than the one in RFC 2190. As of RFC
> 4629, this is the recommended scheme for all variants of H.263.
Yes, this is my understanding too.
> In this packetization scheme, the frame can be split into packets
> regardless of GOB/MB boundaries or anything else. From RFC 4629, section
> A Follow-on Packet contains a number of bytes of coded H.263+ data
> that do not start at a synchronization point. That is, a Follow-on
> Packet does not start with a Picture, GOB, Slice, EOS, or EOSBS
> header, and it may or may not start at a macroblock boundary.
> Splitting packets according to such boundaries would perhaps give better
> handling of dropped packets, but isn't mandated.
Right. This is why I said that the patch is (IMHO) correct but
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