For most profiles to work, it is necessary to have the unstripped version of the libavcodec in the multiverse repository, which can be obtained by installing ubuntu-restricted-extras or kubuntu-restricted-extras or xubuntu-restricted-extras as suggested by this package.
Download and Install CaC:
Ubuntu user can download CaC from here and can install it using your package manager.
Once installed, you can find it in Applications> Sound & Video> CaC - Catch and Convert.
source:http://linuxpoison.blogspot.com/2010/09/135781677510382.html