HowtoMatrix

Ubuntu is crippled on the multimedia front. This is because of copyright and patent restrictions that complicate distribution of proprietary codecs with Ubuntu, which prides itself as a totally free operating system.

Even though Ubuntu developers haven’t included proprietary codecs, they have made it extremely easy for you to install them later through the Medibuntu repository. You can get encrypted DVD playback, Adobe Flash plugin and non-native media files (Windows media, Apple QuickTime, Real, MP3) support by using this single command.
Read more at Ubuntu Unleashed