Does it now or might it soon work with live video from the local camera?
Although, both Firefox and Chrome have been a bit buggy for me with getUserMedia.
Try the Ascii Text effect.
Couldn't get it to work in FF (Mac/22.0) - it asked for camera permission, camera activity light went on, but no images and constant re-prompts for permission. But, worked quite well in Chrome (Mac/27.0.1453.93).