[Mp4-tech] [video]Any body knows RTCP?

[Dave Singer]

At 3:19 PM +0800 8/31/04, lizhengming wrote:
>Dear all,
>
>Does anybody know the RTCP(RTP Control Protocol) protocol, which is one part
>of the RFC1889?
>
>I'm working on RTP and RTCP, trying to send media data with RTP and getting
>the quality of the data transmission through RTCP feedback. I think I devise
>the RTCP packets according to RFC1889,however the packets-loss ratio and
>packets-loss counts drawn from RTCP packets are not always reasonable. When
>the network conditions are good enough and all media data can be
>transmitted, then actual packets-loss ratio and packets-loss counts are all
>equall to zero, and packets-loss ratio and packets-loss counts drawn from
>RTCP packets are also equal to zero. However, when the network conditions
>are not so good, then the actual packets-loss ratio and packets-loss counts
>are larger than zero, but those parameters drawn from RTCP packets are
>seemingly meaningless, with these two parameters changing rapidly and not
>incrementally.
>
>Though the RTCP applications on the server are devised by myself,I use
>Quicktime player as the client player. So I'm not sure whether there is
>something wrong with the RTCP applications on the server side.

I think there may be two things going on here.
a) we introduced a bug into our RTCP reports a while back and we (and 
no-one else, it seems) noticed at the time.  we hope to fix it soon. 
we do apologize.
b) the reports aren't incremental, but only for each reporting 
period, as I recall.
>
>Who knows where are some example codes of RTP/RTCP applications that can be
>my reference? Please tell me if you have any hints. Thanks in advance.

This would be a good question to take to the AVT mailing list at the IETF.
>
>Regards,
>
>Li Zhengming
>
>
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-- 
David Singer
Apple Computer/QuickTime