Open captions are captions burned permanently into the video image, always visible to every viewer and independent of the player's caption support.
Open gate is a video camera recording mode that captures the full usable sensor area, usually in a taller 3:2 or 4:3…
Optical flow in video and VFX is a per-pixel estimate of how image content moves between frames, used for retiming, motion blur…
Oversampling in video cameras means capturing more sensor pixels than the output resolution and downscaling them, for sharper, cleaner footage.