[FFmpeg-devel] [PATCH] Calculate RTCP SR timestamps from packet timestamps

[Luca Abeni]

Hi Martin,

On Sun, 2010-03-28 at 13:12 +0300, Martin Storsj? wrote:
> Hi,
> 
> Currently, the timestamps for RTCP sender reports are calculated based on 
> the system realtime clock. Since the start time for the RTP muxer can be 
> set through the start_time_realtime field, this may be slightly (or quite 
> much if the user explicitly wants that) different from the actual current 
> time. This leads to sending RTCP SR packets where the RTP timestamp is way 
> off from the RTP packets at the same time.

In my understanding of the RFC, the only important thing is that the RTP
timestamp contained in the RTCP SR packet "matches" the NTP time
contained in the same RTCP packet. Isn't this correct?

I fear your patch can create problems when the application does not send
the frames "regularly", but buffers some of them to perform bandwidth
smoothing.

Have you seen some problems with the current behaviour? Can you describe
them? (maybe some client is making assumptions about some relationship
between RTP timestamps and RTCP timestamps?)

			Thanks,
				Luca