I didn’t get a chance to look at yer patch, but it sounds like you want to look at the "jit.gl.render-over-movie" in the examples>jitter-examples>render folder. This is a very easy way – without having to use jit.op.
You just open it. It is a Max Patch. I would *highly* recommend
reading the documentation, tutorials, and checking out some examples
before posting questions to the list. The above is not a good
indication that you’ve done this at all.