Is there a way of getting the reference to each frame number or movie time when recording directly to disk from jit.qt.grab? I need this to store video files synchronized with sensor data.

I know that it is possible to get the time from jit.qt.record or jit.vcr, but I would assume (please correct me if I am wrong) that the recording functionality of jit.qt.grab is the most efficient?

Thanks for any help.