[mythtv-users] OpenGL vsync broken on Xorg 7.1 or latest nVidia driver?

[Doug Larrick]

John P Poet wrote:
>> I'm running Xorg 7.1 and nvidia 9625 (beta) on my dev box with an
>> MX440 and have my choice between tearing (which I'd never seen from
>> any nvidia driver ever before) or high CPU usage (too high to watch
>> HD), depending on the sync-to-vblank settings in nvidia-settings.
>
> I was not even doing a "nvidia-settings --load-config-only", so I kind
> of discounted this, but you are right.
>
> If I have "0/SyncToVBlank=0" it smooths-out the playback, and the
> stuttering is gone -- but I end up with MAJOR tearing.
>
> If I do not load the nvidia-settings at all, or have
> "0/SyncToVBlank=1", then I do not get the tearing, but have the
> stuttering problem.
>
> My CPU usage does get high with HD material, but is low with SD
> material.  I have the stuttering problem with SD material too.
>
> This is with nVidia driver 9746 on a FX5700LE.
>
> I guess I will try an older nVidia driver.

Hi John,

Just getting back from vacation and saw your note...

Have you played around with 'Option "UseEvents" "true"' in your
xorg.conf?  With a new enough nVidia driver the default video out method
changed from Xv overlay to video texture (just like the newer cards,
which can't do overlay at all), and this new option is necessary to get
it working nicely again.

As far as the debug statements in vsync.cpp -- yeah, that code got
reworked fairly recently I think, and whoever did it probably didn't fix
up the debug statements.

-Doug


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