[mythtv-users] Audio/video sync issues only with mythtv

[Jit V]

Hello,

I seem to be suffering from a audio/video sync issue within mythtv - when 
playing back a dvb recording the audio gets slightly out of sync with the 
video.  The issue only seems to occur from within mythtv - the same nuv file 
being played back in mplayer is perfect.

Does anyone have any ideas?  I think that mythtv/mplayer might be using 
different sync mechanisms, I think that mplayer is using the RTC - is there 
any way of selecting the sync method in mythtv?

My hardware is a Shuttle SN41G2V2, I'm using OSS with the NVidia nvsound 
driver (so that I can get 5.1 output from the spdif with hardware mixing).

This is the output from mythfrontend:


2005-01-03 13:06:05 Opening OSS audio device '/dev/dsp'.
2005-01-03 13:06:05 Audio fragment size: 1024
2005-01-03 13:06:05 Over/underscan. V: 0, H: 0, XOff: 0, YOff: 0
2005-01-03 13:06:05 Using XV port 105
2005-01-03 13:06:05 Image size. dispxoff 0, dispyoff: 96, dispwoff: 1024, 
disphoff: 576
2005-01-03 13:06:05 Image size. imgx 0, imgy: 0, imgw: 704, imgh: 576
2005-01-03 13:06:05 Changing from None to WatchingPreRecorded
2005-01-03 13:06:06 nVidiaVideoSync: VBlank ioctl did not work, 
unimplemented in this driver?
2005-01-03 13:06:06 DRMVideoSync: Could not open device /dev/dri/card0, No 
such file or directory
2005-01-03 13:06:06 Using audio as timebase
2005-01-03 13:06:06 Video timing method: SGI OpenGL
2005-01-03 13:06:06 Refresh rate: 16665, frame interval: 40000
2005-01-03 13:06:06 waiting for prebuffer...
pthread_setschedparam: Operation not permitted
2005-01-03 13:06:06 Running as SUID root would allow some threads to run 
with realtime priority, improving video smoothness.
2005-01-03 13:06:07 waiting for prebuffer...
2005-01-03 13:06:07 prebuffer wait timed out..
2005-01-03 13:06:08 waiting for prebuffer...
2005-01-03 13:06:08 A/V diverged by 3.78358 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:08 A/V diverged by 4.31267 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:08 A/V diverged by 4.397 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:08 A/V diverged by 4.279 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:08 A/V diverged by 3.9405 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:08 A/V diverged by 3.43038 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:08 waiting for prebuffer...
2005-01-03 13:06:08 prebuffer wait timed out..
2005-01-03 13:06:08 waiting for prebuffer...
2005-01-03 13:06:09 prebuffer wait timed out..
2005-01-03 13:06:09 waiting for prebuffer...
2005-01-03 13:06:09 waiting for prebuffer...
2005-01-03 13:06:09 waiting for prebuffer...
2005-01-03 13:06:09 waiting for prebuffer...
2005-01-03 13:06:10 waiting for prebuffer...
2005-01-03 13:06:10 prebuffer wait timed out..
2005-01-03 13:06:10 waiting for prebuffer...
2005-01-03 13:06:10 waiting for prebuffer...
2005-01-03 13:06:10 prebuffer wait timed out..
2005-01-03 13:06:10 waiting for prebuffer...
2005-01-03 13:06:10 A/V diverged by 3.3125 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:11 A/V diverged by 3.2117 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:11 A/V diverged by 3.79002 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:11 A/V diverged by 3.94875 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:11 A/V diverged by 3.7803 frames, extending frame to keep 
audio in sync
2005-01-03 13:06:11 A/V diverged by 3.40398 frames, extending frame to keep 
audio in sync


Thanks