[mythtv-users] Lots of "prebuffering pause" and xvMC error

Rob djrobx at djrobx.com
Mon Jan 2 20:44:01 UTC 2006


As per my previous post, I'm still struggling with getting smooth HDTV
playback.   The system is a 2.8ghz P4 with a FX5200 video card with the
Nvidia 7676 driver.  I am currently using the SVN head revision, but my
problems were there with the 0.18.1 version as well.  

When xvMC is enabled, my CPU usage is only 35-45% playing 1080i.  However, I
get rashes of 

2006-01-02 12:40:54.470 NVP: prebuffering pause
2006-01-02 12:40:54.587 NVP: prebuffering pause
2006-01-02 12:40:54.702 NVP: prebuffering pause
2006-01-02 12:40:54.754 NVP: prebuffering pause
2006-01-02 12:40:54.871 NVP: prebuffering pause
2006-01-02 12:40:54.987 NVP: prebuffering pause

Sometimes several per second, and the audio gets garbled when it gets bad.
I can sometimes tune away and tune back to a channel and it will play
smoothly for some period of time before it breaks up again.    Extra audio
buffering is enabled.  If I disable extra audio buffering, video runs in
slow motion.   I've tried with and without xvMC, no matter what I do my
system has trouble keeping up with the audio.  I've tried ALSA output as
well as OSS.    

The same happens on 720p channels that use even less CPU.   I don't get it?
I've verified that AGP is on, with 8x with fast writes and sideband enabled
(and also without).  

Another interesting error in the log:

2006-01-02 12:08:04.864 VideoOutputXv Error: ProcessFrameXvMC: Failed to get
OSD lock

I can't find any references to this error anywhere on the net.  The
black-and-white OSD does appear.  I'm not sure it's important although I
would like the OSD to perform better than it does.  Any thoughts?




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