I've put together a simplified/clarified patch to demonstrate the problem I'm trying to solve. I have a piece that uses crossfading still images as the primary background, then 2D GL objects in the foreground that act as alpha masks over QT video. I'm still fairly new to Jitter (old to Max/MSP), and so the original version of this piece just mixed video and GL without any concept of optimizing to run on the GPU (and thus, my frame rates were terrible and the patch fell back to software GL).
I've been in the process of rewriting everything to work via jit.gl.videoplane and slab objects, but have hit a block, illustrated in the example patch. I've tried playing with the blend settings of the video (Layer 1) and the 2D objects (Layer 2), but without much luck. My understanding of GL is still fairly limited, and so I'm hoping someone can help nudge me out of this rut. Many thanks!