Hardware video rendering may be disabled for flash 11beta2 for some unknown reason. Hopefully the next beta or release, which ever comes sooner, it will be enabled.
It's been disabled for a very good reason. It doesn't work reliably, and causes xorg to lock up in an infinite loop. Do not override the disabled vdpau feature unless you feel like having to do shutdown -r now from a vt.
Actually, it is Flash's fault in many ways. The original Shockwave developers (before Adobe owned it) had some kind of issue with hardware acceleration of any kind, and intentionally chose not to architect their internals to work with it. Thanks to that, it's now 2011 and Flash is still having trouble making even the most basic use of hardware acceleration for anything. Their Stage3D work is only really even feasible because they're basically writing a whole second rendering framework for it that isn't based on the existing 2D framework. Nothing short of a massive rewrite of the Flash rendering internals (which is a good portion of all of Flash) can really fix their inability to properly use hardware accelerated rendering the ways that other apps can do trivially.
There are SWF players used in the games industry (Flash is popular for building the 2D UIs and HUDs in otherwise high-end 3D games) that solve these problems. ScaleForm is the most popular by far, but I know of four others that have been written for specific games engines that use fully hardware-accelerated rendering that blows both ScaleForm and Adobe Flash out of the water in terms of performance. Unfortunately, nobody ever thinks to Open Source these things. There's the GPL Flash players, but they are still not as efficient as the game-specific ones (partly due to increased generality, partly because nobody in FOSS seems to have a clue how to properly use modern GPUs), and they're not going to help much in the professional markets due to their GPL-ness. (I believe LightSpark is LGPL, but that still means nobody can embed it in an app if they plan on ever supporting iOS, XBox, PS3, Wii/WiiU, DS/3DS, PSP/Vita, or any other OS/device that doesn't allow users to relink binaries. I know, blame the device makers, but for those of us that just want to ship awesome games to people who want to play awesome games, we have to avoid anything with the FSF stamp of full approval like the plague.)
That's tearing due to the compositor's framebuffer. In fullscreen, the compositor is suspended, so that can't occur.
Don't think so. Tearing has been around a lot longer than compositors, and it has always had the same cause -- basically scan-in out of sync with scan-out. The compositor just adds one more place where tearing can happen.
Originally Posted by RealNC
Real tearing happens due to the monitor displaying something on it that no longer exists in the framebuffer at all. Therefore, it can't be captured with anything else than a camera pointed at the monitor.
We're saying the same thing there -- part of the displayed frame is from something that is (suddenly) no longer there, while the other part of the frame is from whatever replaced it.
Youtube can sometimes say what is being accelerated
While playing a youtube video press the right mouse button and choose Show video info. This opens a box at the top right and in the box there are video rendering and video decoding fields and in recent versions of flash they will say whether software or hardware rendering it taking place. On certain systems the result will change when you switch between windowed mode and fullscreen (e.g. it may start to be able to use hardware rendering when it could not previously).
My two test cases (playing the video mentioned earlier in the thread).
Mesa 7.11 - Gallium - Radeon R600 - M880G [Mobility Radeon HD 4200]
Flash displays: Software video rendering, Software video decoding.
/etc/adobe/mms.cfg: OverrideGPUValidation=true (I don't think this is really doing anything with the opensource driver)
Nvidia 280.13 - Nvidia GT560ti
Flash displays: Software video rendering, Hardware video decoding.
In both cases the video looks good to me. In the case of the notebook with Mesa 7.11, it dropped a few frames (I was doing compiles at the time). I guess I'm happy with the beta.