[mythtv-users] video playback too fast

[Christopher Yeoh]

Hi,

When I play a recording, things start out ok, but after a few seconds
the video playback speeds up and the audio starts getting choppy
(trying to keep up with the video I think).

I'm using mythtv-0.19 configured with:

./configure --enable-xvmc-pro --enable-xvmc

Its an Ubuntu dapper installation, on a VIA mini-itx SP8000E
(unichrome pro video).  I've tested the video output with xine and it
seems to work ok (with the expected low CPU load). I'm using the via
driver in Ubuntu dapper (xserver-xorg-driver-via 0.1.33.2-0ubuntu1,
xserver-xorg 7.0.0-0ubuntu15)

In mythtv if I disable the xvmc unichrome hardware decoder (use
Standard instead), the video basically plays back ok - it ocassionally
stutters because the CPU load gets too high without the hardware
decoding help.

This is the output I see from mythfrontend:

stream: start_time: 45970.504 duration: 2756.364 bitrate=6670 kb/s
2006-02-18 01:24:07.736 AFD: Opened codec 0x86e6480, id(MPEG2VIDEO_XVMC_VLD) type(Video)
2006-02-18 01:24:07.738 AFD: Opened codec 0x85a7da0, id(MP3) type(Audio)
2006-02-18 01:24:07.743 AFD: Opened codec 0x9350610, id(AC3) type(Audio)
2006-02-18 01:24:07.762 Opening audio device '/dev/dsp'.
2006-02-18 01:24:07.763 Opening OSS audio device '/dev/dsp'.
2006-02-18 01:24:10.411 Realtime priority would require SUID as root.
2006-02-18 01:24:10.417 TV: Changing from None to WatchingPreRecorded
2006-02-18 01:24:10.671 Video timing method: DRM
2006-02-18 01:24:14.079 NVP::AddAudioData():p2: Audio buffer overflow, audio data lost!
2006-02-18 01:24:14.120 NVP::AddAudioData():p2: Audio buffer overflow, audio data lost!
2006-02-18 01:24:14.124 NVP::AddAudioData():p2: Audio buffer overflow, audio data lost!
2006-02-18 01:24:14.169 NVP::AddAudioData():p2: Audio buffer overflow, audio data lost!

(with lots of the Audio buffer overflow messages continuing).

My guess would be that the video timing isn't working properly. 

Any suggestions on how to fix this? Is there a way of using alternative
video timing methods? 

Chris
-- 
cyeoh at samba.org