x264
x264 is a free software library for encoding H.264/MPEG-4 AVC video streams. The code is written by Loren Merritt, Laurent Aimar, Eric Petit, Min Chen, Justin Clay, Måns Rullgård, Radek Czyz, Alex Izvorski, Alex Wright, and Christian Heine from scratch.
x264 has a strong user community based at Doom9 where discussions for improved development take place.
Developers
Demos
flyingskunk.mkv demo encoded with x264/vorbis/matroska - (96 MB, 640x480, 25 fps, 6 minutes), created using LiVES
