[mythtv-users] XvMC on NVidia with Myth .20 (Anyonegetting goodHD off a P4 3

[Drew Bernat]

On Jan 8, 2007, at 2:30 PM, Brad Fuller wrote:

> XvMC, AFAIK, is a mechanism to offload IDCT and motion compensation
> chores to the GPU. Right?
> Thus, by definition mpeg2 streams from OTA HD are going to be  
> different
> than mpeg2 streams from your PVR card that does the mpeg2  
> encoding.  So,
> the decoding of a stream from OTA HD and from you PVR card are  
> going to
> be different.
>
> What do you mean "XvMC doesn't work"? What leads you to this  
> conclusion

Piles and piles of prebuffering errors, skipping playback - the same  
thing that I was seeing with HD before the latest NVidia drivers (and  
turning off sync to vblank).

I was guessing it was file format. It's kind of annoying, since I can  
play both HD and SD but have to flip the configuration between the  
two. Here's some output:

2007-01-07 20:11:36.371 NVP: prebuffering pause
2007-01-07 20:11:36.394 NVP: Waiting for prebuffer.. 0 uADDDuLD
2007-01-07 20:11:36.793 NVP: Video is 3.20878 frames behind audio  
(too slow), skipping A/V wait.

and

2007-01-07 20:11:36.797 WriteAudio: buffer underrun
2007-01-07 20:11:37.143 WriteAudio: buffer underrun
2007-01-07 20:11:37.412 NVP: Video is 3.22094 frames ahead of audio,
                         doubling video frame interval to slow down.
2007-01-07 20:11:37.560 NVP: Video is 3.50962 frames ahead of audio,
                         doubling video frame interval to slow down.
2007-01-07 20:11:37.728 NVP: prebuffering pause
2007-01-07 20:11:37.750 NVP: Waiting for prebuffer.. 0 DDAuDLUu
2007-01-07 20:11:38.113 NVP: prebuffering pause
2007-01-07 20:11:38.133 NVP: Waiting for prebuffer.. 0 AuDLDADU
2007-01-07 20:11:38.411 NVP: Video is 3.09489 frames behind audio  
(too slow), skipping A/V wait.

Very similar to what I was seeing with HD before tweaking my NVidia  
setup.

Drew

--
Drew Bernat
abernat at zathras.net


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-users/attachments/20070108/b460ff08/attachment.htm