EffecTV is a real-time video effector. You can watch TV or video through amazing effectors.

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Really cool project for applying realtime video effects to video. With the video loopback device you can chain the effects together for even stranger results.

There are a lot of really neat video projects for Linux right now. I wasn't able to get the loopback interface working very happily with 2.6 kernel, but it's not a requirement to enjoy EffecTV.