Is it possible to change frame rate by interpolation in blender? I know Blender does not yet support interpolating frames using any sort of motion detection etc., but is there a simple interpolation routine that uses say alpha blending of adjacent frames to generate new frames, governed by the exact time of the new frame compared to the old frames.

The other way round, if I have footage from a high-speed camera, can I compress the source frames into less output frames using a similar blending routine, something like what games do to simulate motion blur?
For simple results the VSE has a speed control effect strip.

With your strip selected &#8679; ShiftA->Effect Strip->Speed Control, you can then adjust the rate in the properties region N. This will alter the playback speed of the specific strip in the VSE.



To adjust the entire video speed you also have the time remapping settings.