Detecting a loop

you can try something like this (i assume fps is 25, and lenght=1 hour) Code:

If it was looped in the uncompressed domain (i.e. before MPEG-2 encoding), and then MPEG-2 encoded, then unless the GOPs line up with the loop period, the "same" frames won't be the same due to different encoding artefacts. If it was looped in analogue, or even before a noise introducing D>A>D conversion, then you have no chance. At best, the "same" frames might be less different than the "different" frames. Cheers, David.

Thank you for the script, it was of great help! The codec used was MJPEG.