Wikipedia
Ffdshow
ffdshow is a codec mainly used for decoding of video in the MPEG-4 ASP (e.g. encoded with DivX or Xvid) and H.264/MPEG-4 AVC video formats, but it supports numerous other video and audio formats as well. It is free software released under GNU General Public License 2.0, runs on Windows, and is implemented as a Video for Windows (VFW) codec and a DirectShow filter.