[mythtv-users] Choppy video and sound
John P Poet
jppoet at gmail.com
Wed Jan 4 04:13:10 UTC 2006
On 1/3/06, matthew.garman at gmail.com <matthew.garman at gmail.com> wrote:
> On Sat, Dec 31, 2005 at 10:33:14AM -0700, John P Poet wrote:
> > On 12/31/05, Brett Swaim <kf6zql at gmail.com> wrote:
> > > MythTv records great, but playback in full screen (video and
> > > audio) is choppy. If I exit mythtv and use mplayer that exact
> > > recording plays perfectly, it only chops in mythfrontend. I have
> > > ...
> > Are you using OpenGL to synchronize your video refresh?
> How do we check this? Is this something we do or DO NOT want?
OpenGL does not work for everyone. If it does work for you, then you
definately want it. OpenGL provides the smoothest video refresh
On your frontend, in Setup->TV Setting->Playback, the very first
screen should have an option to enable OpenGL.
When you run mythfrontend, you can invoke it like this:
mythfrontend -v playback -l /var/tmp/mythfrontend.log
After you start watching a show, look at the mythfrontend.log file,
and look for something like:
2006-01-03 19:34:05.519 nVidiaVideoSync: VBlank ioctl did not work,
unimplemented in this driver?
2006-01-03 19:34:05.519 DRMVideoSync: Could not open device
/dev/dri/card0, No such file or directory
2006-01-03 19:34:05.540 OpenGLVideoSync: GLX extensions:
GLX_EXT_visual_info GLX_EXT_visual_rating GLX_SGI
X_fbconfig GLX_SGIX_pbuffer GLX_SGI_video_sync GLX_SGI_swap_control
2006-01-03 19:34:05.541 OpenGLVideoSync: x,y -> 960, 540
2006-01-03 19:34:05.931 Using OpenGLVideoSync
2006-01-03 19:34:05.939 Using audio as timebase
2006-01-03 19:34:05.939 Video timing method: SGI OpenGL
If the "Video Timing method" is not OpenGL, then you need to look at
the preceding statements to figure out why.
Also, make sure you are running nVidia driver 7676 or *earlier*.
Drivers after 7676 do not work correctly with OpenGL vsync.
More information about the mythtv-users