The cross-platform open-source multimedia framework, player and server
VLC media player is a highly portable multimedia player and multimedia framework capable of reading most audio and video formats (MPEG-2, MPEG-4, H.264, DivX, MPEG-1, mp3, ogg, aac ...) as well as DVDs, Audio CDs VCDs, and various streaming protocols. See the full features list.
It can also be used as a media converter or a server to stream in unicast or multicast in IPv4 or IPv6 on networks.http://www.videolan.org/mirror-geo.php?file=vlc/1.0.0/win32/vlc-1.0.0-win32.exe
For Ubuntu 9.04 Jaunty
Open Synaptic (System -> Administration -> Synaptic Package Manager). In Settings -> Repositories, make sure you have a "multiverse" repository activated.
Search for vlc and install it. You should also install vlc-plugin-esd, mozilla-plugin-vlc (and libdvdcss2).
Command line way
You need to check that a "multiverse" mirror is listed in your /etc/apt/sources.list.
% sudo apt-get update
% sudo apt-get install vlc vlc-plugin-esd mozilla-plugin-vlc