Wednesday, December 19, 2012

Compiz fullscreen unredirection - update

Update January 2013: Both Ubuntu 12.04 LTS and Ubuntu 12.10 now have this new feature enabled by default!

Here's an update to my previous entry. In summary, the Compiz update for Ubuntu 12.10 is now in the quantal-proposed updates, and enables unredirection by default for fullscreen applications like games. Happy gaming holidays! A new Compiz update 0.9.7.12 enabling unredirection by default for Ubuntu 12.04 LTS users is in the SRU PPA.

Several changes have happened since the last update, addressing some potential issues uncovered by the people testing the updates (thanks to all!). Daniel has again done all the hard work with regards to actual development.

Changes affecting both 12.10 & 12.04 LTS:
  • Some drivers do not offer tear-free Xv output without a compositor (or glXSwapBuffers in general). Therefore there is a new option available, for which the default setting enables redirection exception in case of some common video players (eg. Adobe Flash plugin and Totem). The option is Composite -> Undirect Match (unredirect_match) available in the CompizConfig Settings Manager (ccsm). The most notable driver is intel on Intel SB/IVB. Those newer chips don't support the XvPreferOverlay xorg.conf option that would bring tear-free non-composited Xv video on earlier Intels.
  • The default setting for unredirect_match should be fine for existing users. But if you want to enable unredirection also for the common/default video players and risk tearing on some drivers and some applications, change the unredirect_match option to be just '(any)'. This might help with video playback on older/slower integrated graphics which are only barely powerful enough to play HD videos.
12.04 LTS only:
  • 0.9.7.10 will not be uploaded to precise, it was just used for early testing. 0.9.7.12 currently tested in the SRU PPA enables unredirection by default also on the 12.04 LTS release.
  • Intel and nouveau mesa drivers are now blacklisted from unredirection on Mesa 8.0 because of so far unresolved driver problems. The blacklist is however configurable in OpenGL -> unredirect_driver_blacklist. The default blacklist regexp is '(nouveau|Intel).*Mesa 8.0'. This does not affect other drivers or Mesa 9.0, so those intel and nouveau users that install 12.04.2 LTS after the end of January or opt-in into the 'LTS-Q' hardware enablement stack for existing installations around the same time will not be blacklisted anymore. Update January 2013: on 12.04 LTS (only), as a last minute change, also Mesa 9.0 in combination with Intel or Nouveau is blacklisted by default at least until LTS-Q stack is properly testable. You can modify the unredirect_driver_blacklist in CCSM -> OpenGL. It was found out that at least mesa 9.0 _only_ from x-updates is not enough - Intel has graphics display problems. It is probable that the problems go away with the full 12.04.2 stack (kernel, X.org, libdrm, mesa) at which point the Intel/nouveau blacklisting can be removed.
  • The original unredirect_fullscreen_windows option is actually forced on now, because of potential gconf setting migration problems. Disabling unredirection can be done via the unredirect_match option above, by simply blanking the string in there, including removing the '(any)' part - everything will be redirected in that case.
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