As a Jaunty user, I have to say, you have to compile FFMPEG yourself. But the links he posted. Particularly this one

http://ubuntuforums.org/showthread.php?t=786095

As a guide helped. I wasn't sure if you had to Install x264 but I did that anyway. It's mostly copy and paste from there and you can stop once you've installed ffmpeg.

After that it works just fine.