What would be required to display the video signal from a small camera on Amigas?

[spirantho]

The output signal is a standard composite one, it seems, so you just need a Win/TV card.

If you're using the X1000 you should use the OS4 TV card drivers as a basis to DMA the signal into RAM (not video RAM). You can then do whatever you want with them - use the XMOS chip to check for bright red luminescence (no need to check for green as it can just go unless there's a red light) while at the same time copying the video feed into an overlayed window.

If it's any use to you I can send you all the source to my OS4 TV card (Bt8x8/CX2388x) drivers.

[spirantho]

The bandwidth depends entirely on the resolution you want. If you want 640x480, yes, you'd struggle on a classic. OS4 machines could do it though. TV tuner cards lower the resolution internally though so you could probably get 320x240 ok....