MONOGRAM AC3 Encoder 0.9-for some time I was unable to find a decent free AC-3 encoder DirectShow filter so I’ve decided to make one. I’ve extracted the AC-3 encoder source from libavcodec (ffmpeg project) and wrapped it into a simple filter. The filter is released under the GNU LGPL license. It also takes advantage of a CBaseAudioEncoder base class which I intend to describe soon in a nice tutorial