RE: H.261 video problems - fixed

> Hi Mark,
> 
> > Regarding the comment on the H.261 header (RFC2032),
> > I personally wrote the Codian H.261 codec and (de)packetization code
> > (also H.263 and H.264).
> 
> With the information that I have now at hand, I would like apologies
for
> implying that the remote endpoint was at fault.
> 
> Please be sure that next time I will ask for a trace, and only then
make
> such a
> claim (rather than at the same time).

Guilhem,

Don't worry - I didn't mean to sound like I had taken any offence at
your suggestion that there might be a bug in my code! I'm sure there are
bugs but on this occasion I do not think that this is one of them. Even
so discussions like this are useful. 

For completeness here are the first few RTP bytes from some H.261
packets captured from our co-located MCU (demo.codian.com) today.

80 9f 41 65 1e 1b cd 8a 47 ba 1f e4 01 00 00 00 00 01 08 0e 00 01
80 9f 41 66 1e 1b d9 45 47 ba 1f e4 01 00 00 00 00 01 08 8e 00 01
80 9f 41 67 1e 1b e5 00 47 ba 1f e4 01 00 00 00 00 01 09 0e 00 01
80 1f 41 68 1e 1b f0 bb 47 ba 1f e4 01 00 00 00 00 01 09 8e 00 01
80 9f 41 69 1e 1b f0 bb 47 ba 1f e4 01 00 00 00 00 01 81 31 64 1d
80 9f 41 6a 1e 1b fc 76 47 ba 1f e4 01 00 00 00 00 01 0a 0e 00 01
80 1f 41 6b 1e 1c 08 31 47 ba 1f e4 0d 00 00 00 00 01 0a 8e 00 01

So I=0 and V=1 in the H.261 header in each case.
Note that sbit and ebit are usually zero which looks a bit strange but
is because we use macroblock stuffing to byte-align the bitstream at the
end of each video frame.

Regards,
Mark




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