As you probably know an install of Ubuntu does not include support for non-open source multimedia codecs by default. That means the end user must install the proper packages before being able to take advantage of these media formats (such a Mp3 audio, WMA audio and video DVD). No problem, with this easy guide you’ll be playing music and watching DVD’s in no time. In the first section I’ll show you how to get all the audio formats to work and in the second section I’ll show you how to play all video DVD’s (including those that have copy protection).
Installing full Audio Support
This is very simple. All you have to do is install it by going to the Ubuntu Software Centre and finding the package called “ubuntu-restricted-extras”. Or you can just paste “sudo apt-get install ubuntu-restricted-extras” in Terminal. Note: If you use the Kubuntu, Xubuntu or Lubuntu variants just use kubuntu-restricted-extras, xubuntu-restricted-extras or lubuntu-restricted-extras (10.10 only) packages instead.
Installing support for proprietary DVD formats
Paste “sudo apt-get install libdvdread4” in Terminal and hit enter. When it is finished paste “sudo /usr/share/doc/libdvdread4/install-css.sh” in Terminal and hit enter.
That’s it! Now you should have full multimedia support working on Ubuntu.
Notes: (1) These instructions apply to Ubuntu 10.04 (including variants) and above, Lower versions are untested. (2) Terminal may be called Console or Konsole on other variants of Ubuntu.
Posted by Adam 
Ubuntu for Beginners & Beyond 