On my stack, on digitalocean, i have Ubuntu (13, and i’m deploying a small work that need avconv (former ffmpeg).

I need to convert from WMV to MP4 files and i was getting Unknown encoder ‘libx264’ error.

This is how i’v added video encoder libx264 to my avcodec.

apt-get update
apt-get install libavcodec-extra-53

Tested on
Ubuntu 13.04 (GNU/Linux 3.8.0-19-generic x86_64)
Ubuntu 12.04.3 LTS (GNU/Linux 3.8.0-29-generic x86_64)

Tried to share it!
http://stackoverflow.com/questions/11234662/how-to-compile-avconv-with-libx264-on-ubuntu-12-04/18835133#18835133