Last year I made a set of generators that could be used on video clips to get more precise control over speed changes using an animation graph similar to that available in older versions of Final Cut Pro.
Since the 10.0.6 update to Final Cut Pro, the generators I uploaded in March 2012 no longer work. Here is an effect you can use instead.
With these graphs, the steepness and direction of graph determine the speed and direction that the video clip frames play. The Y co-ordinate of the graph controls which source frame is displayed.
In this case the clip will play back in slow motion (because the angle of the graph line is shallow between the first and second keyframe – the Y co-ordinate is changing slowly), then in faster than normal motion. The video will then freeze between keyframes three and four (because the Y co-ordinate of the graph isn’t changing – the line is horizontal). Between keyframes four and five the video will go into reverse, as the Y co-ordinate is getting lower over time. Between the fifth and last keyframe the video will play back very quickly because the value of the graph’s Y co-ordinate is changing quickly.