[mythtv-users] "Wandering" audio/video sync... What the heck is going on here? (Long Post)

Doug Larrick doug at parkercat.org
Tue May 22 10:54:11 UTC 2007


William Munson wrote:

> 2007-05-21 22:03:41.828 nVidiaVideoSync: VBlank ioctl did not work, 
> unimplemented in this driver?
> 2007-05-21 22:03:41.828 DRMVideoSync: Could not open device 
> /dev/dri/card0, No such file or directory
> 2007-05-21 22:03:41.828 RTCVideoSync: Could not set RTC frequency, 
> Permission denied.
> 2007-05-21 22:03:41.832 Video timing method: USleep with busy wait
<snip>
> Thoughts or suggestions??

Getting one of the better video timing methods fixed will help.  If your 
graphics card is nVidia, try turning on OpenGL vsync in the settings; if 
it's ATI or Intel, investigate why DRM is not loading (nVidiaVideoSync 
is for an ancient nVidia driver).  Either of these vsync methods is 
preferable to RTC or usleep because they're synced to the vertical 
retrace.  Otherwise, at least investigate permissions on /dev/rtc and/or 
CONFIG_HZ in your kernel to use RTC video timing rather than usleep.

Also try without XvMC (if you have the CPU for software decode).

And it could well be your soundcard.  Try turning on "use video as 
timebase" temporarily (you'll have to turn off AC3/DTS passthru) to see 
if that helps.

-Doug


More information about the mythtv-users mailing list