@Sariq, You should understand that XMMS is a music player (MP3, AU, WAV etc.,)
MPlayer, VLC, Totem are movie players. There is a MPlayer plugin for XMMS that lets
you play MPEG, AVI, & other media formats.
Install the MPlayer plugin for XMMS
$ sudo apt-get install xmms-xmmplayer
Ofcourse you must have installed MPlayer already, if not install it:
$ sudo apt-get install mplayer mplayer-fonts mplayer-skins mencoder
After installing the MPlayer & xmms-xmmplayer (Mplayer plugin for XMMS),
you can play MPEG/VCD/DVD/WMV media formats using XMMS!!
For more on what packages you can install see my post Unleash the Power of Ubuntu 6.06
Click here