Get Camera/Video Input Latency

[CosmicBen]

When capturing input for real time AR it would be helpful to know the latency for each frame sent from the camera to help better determine where the Camera was when the frame was captured. Currently there is a time code option for deck link inputs (for some reason this always returns 0 for us and seems to be about frame number rather than actual timecode) but no latency variable. Currently we have just been using a semi-arbitrary number of ms that we assume is the delay and are getting passable but low quality results since latency vary slightly frame by frame (restarting the game or PC changes the latency drastically). We have using a frame buffer for a smoother video streaming but it seems to have little effect making latency appear more consistent.

We hope a general solution can be added since we use a variety of cameras, but we do have a few Blackmagic cameras if this kind of feature can't be supported any other way.