I'm doing a project involving video feedback, and I need to find a way to simultaneously mix two live inputs from two separate cameras so that they are displayed on a single monitor, and I need to be able to record the result for editing in a video program.

I have one older digital sony camcorder, and I'll get another cheap camcorder for this purpose. I have a decent computer, with two 7800 gtx cards and an athlon 4800+ dual core processor.

I know I can do this with a video mixer, but these seem to be a bit pricey (I'm a very poor graduate student) - even on ebay they seem to be at least a few hundred dollars which I don't have.

My question: is it possible to splice the component video outputs from the two cameras together directly by cutting the wires and connecting them together?

I have no idea about signal output, and whether this would be too much for an input device (like the ones below, or the computer itself) to handle, or whether the output would just be a garbled visual mess vs. a nice mix/overlay of the two images.

I'm looking at using a cheap component-to-usb solution to get the video to the computer (for example, the Easycap USB 2.0 Video, or the similar Diamond VC500).

The video resolution doesn't have to be super high quality - I can live with 'okay'. What I really need is to have two simultaneous live camera inputs superimposed over each other on a single screen.

I'm not averse to jerry-rigging, mcguyvering, or otherwise making something from parts either... it just has to be cheap.

Please, all you brilliant people, is there a < $100 solution to my dilemma?

If you connect two video sources to one input using a Y-connector or similar simple method, the results will be unpredictable. You could get ghosting, or one source's material might show up weakly or not at all.

The video mixer provides needed signal isolation and impedance matching.

Not a good idea. Though splitters/combiners work for audio (occassionally), video tends to be less forgiving. You really are going to want to get a mixer if your product needs to be decent.

Now is it possible that I can do all this with one video camera and some software? All I need is the live image from the camcorder superimposed with the very same image but transformed (rotated, colored, whatever).

Does anyone know of a piece of software that does this?

I understand now that the video signals are timed and need to go through SOME process (phase locking) in order to not be garbled. I have a decent computer so a software solution might be best.