A quick and dirty way is to select your frames in the graph editor, push 'r' for scale and then middle click and drag to the left until you get the scale to -1.
"Stack map" which is a texture where the R is something, G something else, B something else, and A something else. I'm sure there is a ton of other terms for this.
Like ZacD metioned, mask out RGB, do your operations, then do an append node with R and G as the inputs with the output of that going into a second append with B.
well, the idea would be to have one mesh, with a greyscale diffuse that gets colored through the shader, the colors being R,G and B were just for simplicity