** Description changed: You might expect that with "Sync To VBlank" enabled in compiz that video tearing doesn't happen. But it does, just less often. This is normal, expected behaviour. The cause is that compiz (up to 0.9.6 at least) uses GLX_SGI_video_sync, which provides a rough way of synchronizing with the video frame rate of the monitor. But it's not reliable in most cases because if you take a little too long to render the frame, then you can miss the frame deadline and tearing can still be seen. - The solution to this bug is to modify compiz to use GLX_SGI_swap_control - instead, which provides a more reliable and more efficient way of - synchronizing with the refresh rate. However to use GLX_SGI_swap_control - means your code must use glXSwapBuffers for every frame. Compiz - presently does not use it for every frame. + The solution to this bug is to modify compiz to use glXSwapBuffers for + every frame. And possibly, optionally, use GLX_SGI_swap_control for + synchronization, though it might not be necessary when using pure buffer + swapping. Speaking with smspillaz, he says a move to 100% glXSwapBuffers is planned for a future version of compiz, not least because it is required - in order to port compiz to OpenGLES. Once compiz uses glXSwapBuffers for - every frame, it will be possible to then use GLX_SGI_swap_control for - reliable synchronization. + in order to port compiz to OpenGLES. More info: http://www.opengl.org/wiki/Swap_Interval - WORKAROUND: In CCSM, Workarounds, enable "Force full screen redraw (buffer swap) on repaint". - ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: compiz 1:0.9.6+bzr20110929-0ubuntu5 ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4 Uname: Linux 3.0.0-12-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 1.23-0ubuntu3 Architecture: amd64 CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,mousepoll,place,gnomecompat,resize,imgpng,move,wall,regex,grid,vpswitch,animation,session,resizeinfo,unitymtgrabhandles,expo,workarounds,fade,scale,ezoom,unityshell] CompositorRunning: compiz Date: Mon Oct 24 16:01:07 2011 DistUpgraded: Fresh install DistroCodename: oneiric DistroVariant: ubuntu GraphicsCard: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0102] (rev 09) (prog-if 00 [VGA controller]) Subsystem: Dell Device [1028:047e] InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) MachineType: Dell Inc. OptiPlex 990 PackageArchitecture: all ProcEnviron: LANGUAGE=en_AU:en PATH=(custom, no user) LANG=en_AU.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-12-generic root=UUID=c9a0c042-2d94-4c4b-bb7f-756faf723ada ro quiet splash intel_iommu=on vt.handoff=7 SourcePackage: compiz UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/28/2011 dmi.bios.vendor: Dell Inc. dmi.bios.version: A05 dmi.board.name: 0D6H9T dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 15 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA05:bd05/28/2011:svnDellInc.:pnOptiPlex990:pvr01:rvnDellInc.:rn0D6H9T:rvrA00:cvnDellInc.:ct15:cvr: dmi.product.name: OptiPlex 990 dmi.product.version: 01 dmi.sys.vendor: Dell Inc. version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu5 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.26-1ubuntu1 version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu3 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu3 version.xserver-xorg: xserver-xorg 1:7.6+7ubuntu7 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu2 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110411+8378443-1
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/880707 Title: Video tearing still occurs in compiz (less so) when "Sync To VBlank" is enabled. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/880707/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
