Intel i915GM (xf86-video-intel modesetting) Tearing during playback with XV

[Michel Dänzer]

On Wed, 2007-02-21 at 14:47 -0800, Keith Packard wrote:
> On Wed, 2007-02-21 at 20:47 +0100, Lukas Hejtmanek wrote:
> 
> > according to sources, G965 does not provide video overlay. It provides 
> > textured video only. (at least it does not setup adaptor for video overlay for
> > G965). Anyway, using xvinfo, can you see attributes like saturation or gamma
> > for any adaptor? If not, you are only using textured video thus you cannot
> > expect tearless video.
> 
> Right, the G965 eliminated the overlay so the driver provides only
> textured video. It would be fairly easy to stick a spin loop into the
> server blocking for vretrace before painting a frame of video; I don't
> like to do that in general because of performance issues, but it might
> be worth a try to see if that eliminates the tearing issue.

I wonder if the support I added to the DRM recently for scheduling DRI
buffer swaps couldn't be used for this. Things might be more complicated
with a compositing manager though. Do we know whether the tearing is due
to the colourspace conversion blit or the compositing manager's reaction
to the damage event, or possibly even both?


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer