Comment 36 for bug 1643467

I had this problem too. I'm running Lubuntu 12.04. I use plain 12.04 and not LTS because lubuntu 12.04 LTS requires PAE and won't work on my Pentium M Itronix go book 3. I have to keep running Lubuntu 12.04. Anyway the answer for me was to go to the Lubuntu Software center and install Gnome-Media-Player . While installing looking at the "programs to install" lo and behold at the top of the list...Libavcodec53 !!! PROBLEM SOLVED.
     roger at blueshade44