[PD] Installation with GEM

[Florian Grond]

Dear List,

I would like to realize an installation in GEM but I don't know if there 
are appropriate objects or If I have to teach myself how to program them.
If you could give me advise which direction to go I would be very pleased.

Two cameras would send their frames to two image stacks which contain 
say 30 frames (the more the better).
The actual frame is subtracted from the last one and the resulting frame 
of this simple kind of movement-dedection would serve as a parameter to 
compose from the two stacks the actual video output reading each single 
pixel in a random manner from the two stacks mixing both by using an 
appropriate function.

Does anyone have an idea how to realize that with existing objects, and 
if not, where do I find good documentation to learn how to program GEM.

Thanks a lot,

Florian