From Around The Web: The ffmpeg libav Situation
Quite a nice little perspective on what the situation looked and looks like recently between the ffmpeg and libav camps. libav was created as a fork aside from ffmpeg, and has met both opposition and praise from some. It really depends on how you came across either. For me, I have always known ffmpeg since I heard about it around 2006, and it serves me well. However, some developers prefer otherwise. Be sure to hit up the source link for more.