[mythtv-users] MythTV 0.24 and vsync on Nvidia / Fedora 14 / RPMFusion

[Jimmy Rentz]

On Sat, 27 Nov 2010 13:47:38 -0600
George Mari <george_mythusers at mari1938.org> wrote:

> On 11/27/2010 12:35 PM, Jimmy Rentz wrote:
> > On Sat, 27 Nov 2010 12:56:10 -0500
> > Boleslaw Ciesielski<bc-mythtv at comcast.net>  wrote:
> >
> >> On 11/27/2010 12:09 PM, George Mari wrote:
> >>> The upgrade was exceptionally smooth and trouble-free, except for
> >>> one minor annoyance with playback on all front ends - my video
> >>> timing method has gone from "SGI OpenGL" to "USleep with busy
> >>> wait". I had tackled and solved this problem several years ago,
> >>> and I thought I remembered having to enable OpenGL Vsync in the
> >>> Nvidia driver via the Nvidia-settings program, which I confirmed
> >>> was still on, but to no avail.
> >>
> >> Did you make sure that the user running the frontend has write
> >> access to /dev/nvidia* device files?
> >>
> >> Bolek
> >
> > OpenGL vsync was disabled in .24:
> > http://svn.mythtv.org/trac/changeset/26314.
> > Make sure that XVideo/XV Texture sync to vblank is set
> > in nvidia-settings.
> 
> Ahh, OK - that's good to know.  Reading the description at that link
> was very helpful - thanks!
> 
> OK, but now, I still seem to be unable to explain why this isn't
> working for me.
> 
> I do have the various XVideo sync to vblank parameters set in 
> nvidia-settings - I wrote them to file to paste here:
> 
> 0/XVideoTextureSyncToVBlank=1
> 0/XVideoBlitterSyncToVBlank=1
> 0/XVideoSyncToDisplay=1
> 
> 
> Also, from the verbose output I posted earlier, mythfrontend does
> seem to be confirming that it sees sync to vblank set for Xvideo:
> 
> ...
> 2010-11-27 10:28:03.920 VideoOutputXv: XV_SYNC_TO_VBLANK supported
> 2010-11-27 10:28:03.920 VideoOutputXv: XVideo Sync to VBlank set
> ...
> 
> But when it comes to actual playback, it doesn't seem to be able to 
> actually use the sync to vblank method:
> 
> ...
> 2010-11-27 10:28:04.055 VideoOutput: Using deinterlace method 
> yadifdoubleprocessdeint
> 2010-11-27 10:28:04.056 VSYNC: DRMVideoSync: Could not open device 
> /dev/dri/card0, No such file or directory
> 2010-11-27 10:28:04.056 VSYNC: RTCVideoSync: Could not set RTC 
> frequency, Permission denied.
> 2010-11-27 10:28:04.057 Player(0): Video timing method: USleep with
> busy wait
> 2010-11-27 10:28:04.058 Player(0): Display Refresh Rate: 59.977 Video 
> Frame Rate: 29.971
> ...
> 
> My understanding from searching the mailing list archive is that the 
> message about /dev/dri/card0 is not relevant - can anyone confirm?
> 
> And the message about permission denied when trying to set the rtc 
> frequency would only be of concern if I was trying to use that
> method, correct?
> 
> Maybe I will just try to get the permissions right on dev/rtc and/or 
> dev/hpet, just to see if I can make some progress.
> _______________________________________________
I believe the nvidia driver is doing the sync to vblank
automatically when a display call is made (probably prior to firing
display data to the card).
/dev/dri/card0 (DRMVideoSync) is used for freedesktop display
driver vblank methods.  Only the intel drivers support that
currently.
The other timing methods (rtc/hpet/usleep) are just used as
fallbacks.