Thanks for the answer, with this new information I think an AE script is not the ideal environment for what I have in mind,
so I will try other approaches such as Processing, open Frameworks, or Max Jitter.

Thanks!

I am trying to write a script that takes a clip and analyzes how much "motion" is in it by simple motion detection (comparing pixels on consecutive frames). Roughly I want to use the same idea that this Processing sketch uses, however I'm not sure if the methods used here exist or are poss...