I am trying to record from multiple firewire cameras and get a rough synchronization between them. I just need to be able to get some sort of output from jit.qt.grab which tells me how many frames have been written while it is recording to a file. is there any way to couple "unique 1" with "write_preview" so that I can get a preview image only when a new image has been received from the camera? Is there any way just to get a bang signal every time a new frame is recorded?

thanks.