I see mencoder is supposed to be able to record audio from an alsa audio source, but I've never been able to get it to work. (I can start up arecord in the background, then combine the audio and video with a 0.4 second delay, and have it work reasonably well, but that seems kinda klunky). Any handy apps for recording video and audio simultaneously (with a v4l2 only driver - not the original v4l)? All the fancy DVR apps I've tried seem to freak out when presented with a video source that doesn't have a tuner (maybe it would be simpler to hack the driver to pretend to have a tuner, but always tune to the same channel :-).
