[FFmpeg-trac] #5739(undetermined:new): Invalid RTCP SR package sent by ffmpeg

[FFmpeg]

#5739: Invalid RTCP SR package sent by ffmpeg
-------------------------------------+-------------------------------------
             Reporter:  sancane      |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 ffmpeg is sending an invalid RTCP SR packet, we detected that with the
 version 2.8.6 of ffmpeg, the RTCP SR sent by ffmpeg does not increment the
 ntptime, as we could expect so the clock is supposed to be monotonic, This
 makes it impossible to use RTCP SRs to synchronize. It seems to be a
 regression from any commit introduced from version 2.7.2 wich were doing
 it well.

 Next is the information about SR sent with ffmpeg 2.8.6:

 {{{
 0:00:41.314525104 Received RTCP SR packet SSRC: 535359325, rtptime:
 3030375347, ntptime: 9223372036854775808, ntpnstime:
 596523:14:08.000000000
 0:00:46.323753635 Received RTCP SR packet SSRC: 535359325, rtptime:
 3030826067, ntptime: 9223372036854775808, ntpnstime:
 596523:14:08.000000000
 0:00:51.355472637 Received RTCP SR packet SSRC: 535359325, rtptime:
 3031278947, ntptime: 9223372036854775808, ntpnstime:
 596523:14:08.000000000
 0:00:56.391561089 Received RTCP SR packet SSRC: 535359325, rtptime:
 3031732097, ntptime: 9223372036854775808, ntpnstime:
 596523:14:08.000000000
 0:01:01.422186827 Received RTCP SR packet SSRC: 535359325, rtptime:
 3032184797, ntptime: 9223372036854775808, ntpnstime:
 596523:14:08.000000000
 }}}

 Here is the one captured with ffmpeg 2.7.2:
 {{{
 0:00:50.725134082 Received RTCP SR packet SSRC: 2102232704, rtptime:
 2173288374, ntptime: 15799514243063691084, ntpnstime:
 1021836:24:30.631000000
 0:00:55.757820842 Received RTCP SR packet SSRC: 2102232704, rtptime:
 2173741254, ntptime: 15799514264675966517, ntpnstime:
 1021836:24:35.662999999
 0:01:00.760914175 Received RTCP SR packet SSRC: 2102232704, rtptime:
 2174191524, ntptime: 15799514286163687899, ntpnstime:
 1021836:24:40.665999999
 0:01:05.793591156 Received RTCP SR packet SSRC: 2102232704, rtptime:
 2174644494, ntptime: 15799514307780258300, ntpnstime:
 1021836:24:45.699000000
 0:01:10.819718742 Received RTCP SR packet SSRC: 2102232704, rtptime:
 2175096834, ntptime: 15799514329366763930, ntpnstime:
 1021836:24:50.725000000
 }}}

 How to reproduce:
 {{{
 % ffmpeg -re -i -an -vcodec libx264 -profile:v baseline -level 3.0 -f rtp
 rtp://SERVER_IP:PORT
 ffmpeg version 2.8.6
 built on ubuntu xenial
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5739>
FFmpeg <https://ffmpeg.org>
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