Ubuntu restricted formats

Ubuntu strives to make all software that meets the licensing terms in the Ubuntu License Policy available. However patent and copyright restrictions complicate free operating systems distributing software to support proprietary formats. If you still want to play most common multimedia formats, including MP3, DVD, Flash, Quicktime, WMA and WMV, including both standalone files and content embedded in web pages, you have to install the restricted formats package.

sudo apt-get install ubuntu-restricted-extras