[mythtv] [PATCH] XVideo XvMC VLD broken

Terry Barnaby terry1 at beam.ltd.uk
Tue May 3 20:17:47 UTC 2005


> It looks like the problem is with AVSync (again !).
> 
> If I set "disableaudio" in NupplePlayer.cpp video display is fine.
> If I set "avsync_avg = frame_interval" at the top of
> NuppelVideoPlayer::WarpFactor() all is Ok (bar audio delayed/infront).
> 
> What is supposed to happen in NuppelVideoPlayer::AVSync() when
> "diverge > MAXDIVERGE" ?
> Could it be that with XvMC VLD video frames are not actually "extended" ?
> 
> Terry
> 

I have put some debug statements into NuppelVideoPlayer::AVSync().
It appears that the Video output frame rate has been cut in half
(as it should be) and the correct Video frames are being output
at this rate however the audio seems to have slowed down to match ?
The Audio should be running at normal speed and would catch up with
the Video.
I note that if I set "enable Extra Audio Buffering" the situation
is improved drasticly. However, is this just covering up some
other issue ?
Any ideas on this ?

What I see is the following:

2005-05-03 21:09:07.629 A/V diverged by 6.47223 frames, extending frame 
to keep audio in sync
BEAM: AVSync: 1115150947.630 Video: 63139634 Audio: 63139396 Diff: 238
WarpFactor: 253666 40000
2005-05-03 21:09:07.709 A/V diverged by 6.34165 frames, extending frame 
to keep audio in sync
BEAM: AVSync: 1115150947.710 Video: 63139674 Audio: 63139441 Diff: 233
WarpFactor: 248499 40000
2005-05-03 21:09:07.789 A/V diverged by 6.21247 frames, extending frame 
to keep audio in sync
BEAM: AVSync: 1115150947.790 Video: 63139714 Audio: 63139463 Diff: 251
WarpFactor: 249124 40000
2005-05-03 21:09:07.869 A/V diverged by 6.2281 frames, extending frame 
to keep audio in sync
BEAM: AVSync: 1115150947.870 Video: 63139754 Audio: 63139486 Diff: 268
WarpFactor: 253843 40000
2005-05-03 21:09:07.949 A/V diverged by 6.34608 frames, extending frame 
to keep audio in sync
BEAM: AVSync: 1115150947.950 Video: 63139794 Audio: 63139529 Diff: 265

Terry


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