Thanks for the reply.
I am interesting in using HAP because it allows for videos with an alpha layer.
Also, i am right away loading the videos back in to my software and do not have the time (and code) for transcoding.
I liked the idea of HAP because as i understand it it uses the GPU for decoding and faster loading:
It would be super if the next version of syphon recorder has some sort of apple script or OSC communication possibilities.