Gephex homepage

example effects:

 
sound reactive effect   An effect that reacts to sound. Click on the image to download. Put it into ~/.gephex/0.4/graphs. You need to select a video or image in the image source module.   To make the sound work, you have to capture from your soundcard (e.g. on linux with alsamixer or on windows with the mixer). Then you can use any music player (winamp, xmms,...)
 
fzcam   Another effect that reacts to sound. Click on the image to download. Put it into ~/.gephex/0.4/graphs.   To make the sound work, you have to capture from your soundcard (e.g. on linux with alsamixer or on windows with the mixer). Then you can use any music player (winamp, xmms,...)
 
For more and better graphs have a look at these examples created by Pierre Mersadier.