best way for capturing video in jitter? jit.qt.record? jit.qt.grab?

Hello all,

I try to use jit.qt.record for capturing, but I get only low quality at low framerates.
I capture 720p 50 via a Blackmagic Card.

I originally used jit.qt.grab directly for capturing. That worked actually fine, but with strange delay as you can see here:
https://cycling74.com/forums/jit-qt-grab-with-capture-delay-in-snow-leopard

My project is all about good timing... I basically have to capture some scenes of a person in a greenbox. The person is doing 3 different actions and I have to record one clip for each action. I thought in the worst case I have to record the clips to disk then open them immediately in the max patch and then somehow set the in and out points manually and then export... I seem to be very desperate right now :)

many thx,
florian