Overlay Blending Mode for Film Grain.

I can use DaVinci Resolve Live to add a realtime film grain(looping video file set to overlay blending mode.) overlay over my stream, but it would be really nice to be able to handle this in directly in OBS somehow. Wondering if anyone has any ideas how this could be done. A filter? A shader? Adding to the built in blending modes? Just wanted to get the conversation started and see if anyone has any thoughts.

Ideally this would be handled by the gpu.