Tools for comparing video?

[rigop]

Is there any fully free software to automatically find the video duplicates on HD.

[vood007]

I use MTN (http://moviethumbnail.sourceforge.net/) to create 4x4 contact sheets without text header of my videos and then i use SimilarImages (https://tn123.org/simimages/) to find the dupes. Both tools are free, stable and very fast.

[rigop]

Thanks for your solution.
I've tried some solutions, but they are not free. Is there other equivalents ?