[gstreamer-bugs] [Bug 549774] New: audio / video synchronization glitch during rtsp playback

[GStreamer (bugzilla.gnome.org)]

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  GStreamer | gst-plugins-base | Ver: 0.10.18
           Summary: audio / video synchronization glitch during rtsp
                    playback
           Product: GStreamer
           Version: 0.10.18
          Platform: Other
        OS/Version: All
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: gst-plugins-base
        AssignedTo: gstreamer-bugs at lists.sourceforge.net
        ReportedBy: l1x7qnm02 at sneakemail.com
         QAContact: gstreamer-bugs at lists.sourceforge.net
     GNOME version: Unspecified
   GNOME milestone: Unspecified


Please describe the problem:
I have a 2 mbit/sec video clip being streamed as rtsp over localhost from
Darwin Streaming Server.  My command line is:

gst-launch -v playbin uri=rtsp://localhost/filename.mp4

A few seconds into the clip, the audio drops out for just under a second, and
gst-launch prints this:

WARNING: from element /playbin0/abin/audiosink/audiosink-actual-sink-alsa:
Compensating for audio synchronisation problems
Additional debug info:
gstbaseaudiosink.c(1190): gst_base_audio_sink_render ():
/playbin0/abin/audiosink/audiosink-actual-sink-alsa:
Unexpected discontinuity in audio timestamps of more than half a second
(0:00:00.811836734), resyncing

>From that point on, audio and video remain out of sync by just under a second.

VLC and mplayer handle this stream with no such problem. Gstreamer plays the
video clip directly from the filesystem with no such problem. The glitch only
shows up when using gstreamer to stream it as rtsp://localhost.

I'm guessing gst-plugins-base is causing this because I think it contains
audiosink-actual-sink-alsa, which seems to be emitting the warning message.

The video clip in question is encoded using h.264 video and aac audio.  I'm
running xubuntu hardy, which includes gstreamer-plugins-base 0.10.18.


Steps to reproduce:


Actual results:


Expected results:


Does this happen every time?


Other information:


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