Speed ramp

Rather than setting one speed for a clip, you keyframe the speed so it climbs and falls across the shot. The common use is a whip or a movement that ramps up to several times normal speed, cuts, then decelerates into the next shot, which hides the join and carries energy across it. Doing it well needs footage shot at a higher frame rate, so the slow section still has real frames to show instead of duplicated ones. Overuse is the usual problem. A ramp on every transition stops reading as emphasis within about ninety seconds and starts reading as a template.