Hi Jeffli,
apologies for the late reply. I have tried your suggestions, and they do not fix the framerate problem. In a separate test I noted that if the resolution is lowered to 480x270, the framerate is 60fps as expected. I also found a method here (Syncsensor - multiple camera, jpeg Consumer - #3 by sathish.nitt76) that uses CUDA streams to convert to gpumats - could this be of use?
Appreciate the help!