Live animation with pygame and video4linux

 EDIT: I've uploaded the code (and merged it into one file) on gitorious.

Last Friday, the SAT saw the premiere of a new work by Alexandre Quessy and Isabelle Caron called Motifs Urbains. The work was part of the experimentation phase of the propulse[art] project. The demo involved Alexandre generating live, multichannel audio and looping it, while at the same time in a separate room Isabelle did live stop-motion animation and looped it using Alexandre's Processing-based software, ToonLoop. Both rooms featured simultaneous playback of the audio and animation.
Inspired by the demo and my recent tinkering with pygame, I decided to try and write a prototype for a simple stop motion animation looper like ToonLoop. The result is cam_loop.py. Thanks to Nirav Patel's 2008 Google Summer of Code project, pygame (subversion revision 1744 or later) now supports video4linux camera input. The camLoop program shows the camera playback in the left hand region of the window, and the animation in the right hand of the video. The user can then grab frames live, and the accumulated frames will be played back in the right hand side of the window:

If you run the program during the winter months, you'll be subjected to a nauseating holiday theme overlayed on the incoming video. This example was simply to demonstrate how it's possible to easily draw arbitrary objects on live video. From Nirav's blog, it would appear that CoreVideo support is also forthcoming.