When I try to play Flash videos in full screen, sometimes - but not all the time, which makes this bug so aggravating! - the video gets very, VERY choppy, and UI controls do not really respond at all. Sound works fine. Disabling Compiz does nothing to alleviate the problem (switching to Ubuntu Classic (No Effects) - I even created a new user just to test this out to make sure it wasn't a local configuration problem).
This problem exists both in the latest beta build of Chrome and the most up-to-date Firefox with latest Flash. No problems when I watch a video in full-screen, it seems to be just Flash.. and videos tend to play just fine when not in full-screen mode.
I'm on a Thinkpad W510 with an nVidia Quadro FX 880M graphics card.
If anyone could be help this would be much appreciated.
NOTE: This is the workaround for youtube. Still, same prinicple should work on any flash-based content.
If none of suggestions worked and if your videos play well in any resolution i.e. 480,720,1080 when flash content is not maximized and lag/stuttering/choppiness occurs only in full screen mode, try this: try right-clicking the video and select pop out video. Then, just press F11 and the video should be still playing well with no lag.
This works for me and I'm using dell dual-core t220 2.0 Ghz, 2GB ram with ati radeon HD 3200 video card and using the ati official proprietary driver 12.1. Long story short, if You are using proprietary ati drivers and lag occurs only in full screen, try poping out the window and maximize it instead pressing the full screen button on the flash player instead. Also, turning of Vblank in ccsm also helps for overall performance.
Install Flash-Aid and run the extension wizard. It will detect installed flash plugins, remove them and install the best option according to your system architecture and version. Additionally, it will apply some tweaks that should improve performance and fix those common issues.
If you experience black video on full screen after that on YouTube, then run the Wizard again and install Flash Beta or disable the option to "Override GPU validation".
Try using gnash instead of flash it works for me on you tube fullscreen just fine no choppyness less errors and browser crashes .
sudo apt-get install gnash
MacOS and Linux flash plugins from Adobe are lacking GPU Acceleration, which is present in the Windows versions. Thus, decoding higher quality video tends to be choppy at times, even on high performance machines.
What you can do is go to http://www.youtube.com/html5 and enable the HTML5 Trial, it helps a lot, but only works for videos that don't contain advertizements (for now), so those will still fallback to Flash.
That said I had never heard of Gnash, guess I'll have to test that as well. :)
In case you never get the fullscreen to work, running this might just do the trick: