and some other open-source tech
http://www.dailymotion.com/video/x1rzil_sounds-like-light-lights-sound
Raw video footage is cooked using a custom OpenCV-based app that feeds data to PD via Open Sound Control packets. PD is used for the sound generation and also for the higher level control functions of the lighting rig.
more details here http://www.frey.co.nz/soundslikelight/