[gst-devel] seeking mpeg, test results

Joshua N Pritikin vishnu at pobox.com
Tue Jan 14 03:26:02 CET 2003

The video usually works great.  It seeks to the previous I-frame and then plays
forward until it finds the desired frame.  This part works.  However, there
are a number of related problems.

* Empirically, i feel like the audio is not flushed after a seek.  Worse,
the audio resumes playback from the previous I-frame (instead of from the
desired frame).  So it takes at least 3-4 seconds before the audio gets
back in sync with the video, at a minimum.  This is bad.

mpeg2dec needs to deliver more information when passing the seek event
upstream so mpegdemux can skip the audio between the previous I-frame
and the desired frame.

This might seems like a minor problem, but my application needs to
play lots of very short clips.  Each clip is typically less than
one second.  So, typically, the audio and video never get sync'd
at all, ever.  It's frustrating.

* After a seek, sometimes libmpeg2 state gets messed up and it reads
outside of valid buffers.  This happens fairly often with non-standard
MPEG, but i've also seen it (less often) with VCD conformant streams.
This is easy to identify using the optimal scheduler and valgrind.

i have no clue how to fix these problems myself so i guess it's
time to see how well the ffmpeg plugin works ...

Victory to the Divine Mother!!         after all,
  http://sahajayoga.org                  http://why-compete.org

More information about the gstreamer-devel mailing list