In earlier iterations of Quicktime and Mac OS, I used to encode videos as divx or xvid, then duplicate them and cancel the duplication before it finished. The result was these corrupted files that, as you scrubbed through them, retained some earlier frames cross blurred/broken/smeared with later frames. My trick no longer works with modern software.

I guess this is a long shot, but I faintly remember someone somewhere who made a way to produce this effect through code, but I can’t figure out how to find his site, if it still exists.

I’m sorry I can’t follow up with an illustrative example, but the relevant images are on a separate drive. Thanks for any insight!