[osflash] masking moving shapes in live video

[Thom Shannon]

I'm trying to work out a way to pick out moving objects in a live video 
feed and use it to mask some graphics over-layed on the video. Basically 
it's so that the graphics would appear to be behind people moving in the 
foreground. The plan is to use red5 to relay the video and I was 
thinking about generating the mask on the server using a reference still 
frame and streaming it to the client separately.

Does anyone have any ideas? Thanks.