If you have nVidia or ATi/AMD display card, you can playback HD video files on Ubuntu 11.04 desktop.
Samiux
HOWTO : HD video playback on Ubuntu 11.04 Desktop
Archived thread 1751647 from Hong Kong Team. Markdown source: Hong_Kong_Team/thread_1751647_HOWTO__HD_video_playback_on_Ubuntu_11.04_Desktop.md