Xv performance and quality issues at 1920x1080/60 resolution

[Jason Keirstead]

On Mon, Sep 15, 2008 at 3:33 PM, Roland Scheidegger
<sroland at tungstengraphics.com> wrote:
> I think what you're seeing are artifacts due to the video update not
> being synced to vblank. This used to be much worse (because it tended to
> be a full diagonal split, whereas now I only see this in small parts of
> the screen).
> Alex Deucher has done some initial work on this, though I'm not sure it
> actually works currently.
> http://cgit.freedesktop.org/~agd5f/xf86-video-ati/log/?h=vsync_accel

I probably should have mentioned this before but this is a MythTV box.
as such I do currently have the "Sync to VBlanK" option in myth
enabled, though I am unsure if this works or does anything at all with
the ATI driver. I know it works with the closed-source NVidia driver
on my other machine.

> As long as dri gets enabled, I don't think there's much you can do.
> Though if the bottleneck is the cpu, it might help if the driver could
> do planar video instead of converting it to packed.
> What content are you playing back? In particular, if this is some h.264
> content coming from some DVB stream using xinelib to decode, xinelib (at
> least released versions) might not be able to use both cpu cores to
> decode, a X2 6400+ will likely indeed be too slow in this case. If that
> isn't the problem, I'm not sure if the gpu could really be too slow -
> sounds unlikely (though for maximum gpu performance you'd want to make
> sure you're using dual channel memory).

I do have dual channel memory ( 2x1 GB ). The content is over DVB but
it is not H.264 - it is MPEG2 @ 1080i . The CPU is not th ebottleneck
- if I pop in another video card the box can process the video no
problem.

-- 
In theory, there is no difference between theory and practice. But, in
practice, there is.

- Jan L.A. van de Snepscheut