Nope, UI3 can't know the actual timestamp until each video frame arrives (and then it only knows for H.264 streams, not JPEG). Blue Iris doesn't allow this, but it is a possibility for the future. I really want this feature too Can't do this because UI3 doesn't know where the gaps are in your clips. Yeah it would be possible to build something similar to the timeline control that is in Blue Iris's local console (minus multi-camera playback). It was on my original UI3 design but I cut the feature because it simply isn't very useful until multi-camera simultaneous playback becomes possible.