[mythtvnz] VDPAU tearing - disable composite script?

[Brett]

> The tearing problem affects the top few inches of the picture only,
> and manifests as slight distortion of the picture, and only occurs
> during fast motion on 1080i feeds (such as the rugby). The generally
> accepted workaround is to disable compositiing in xorg.conf
> (http://www.mythtv.org/wiki/VDPAU).
> 
> However, as I use my mythbox - which is both the FE and BE - as my
> main PC, it's a pain to disable compositing (and restart X) just to
> watch HDTV without tearing, since I can't then run gnome 3 shell
> without re-enabling compositing and restarting X.
> 
> Any idea of a shortcut or suggestions for a script to automagically:
> 
> 1) disable compositing & restart X
> 2) launch mythfrontend
> 3) on quitting out of mythfrontend, renable compositing and restart X
> 
> Any other workarounds?
> 

> 
nVidia composite & VDPAU don't work well together..

I recently made up a mythtv demo box from old bits with 11.04 Ubuntu so
unity/compiz..

The VDPAU playback is screwed up by composite redirection.
Composite uses blitter which (apparently) does not work with VDPAU
overlays.
nVidia says it is Xorg who say it is compiz who blame nVidia. Or
something as silly.

Using compiz composite setting manager ccsm:
composite tab, tick un-redirect full screen
workarounds tab, tick legacy full screen support.

This worked well for 11.04 unity 9400GT VDPAU MythTV 0.24+fixes driver
270.xxx.x

Interestingly qvdpautest does not reflect VDPAU-composite/compiz
interaction.