Comment 25 for bug 197957

Mike, it's not a technical problem, it's a legal / moral / philosophical one. The ALSA plugin is just a wrapper for liba52, which is in turn just a wrapper for ffmpeg, specifically libavcodec. The latter has to be built with a52 support at configure time before it is compiled. This is disabled by default because it is covered by patents (non-free). I know this because this was an area of concern for us over at the Avaneya project.