That may come with some challenges when it comes to 32 bit vs 64 bit applications ....
(Microsoft documentation) .... on a 64 bit system Windows Explorer extensions must be implemented as 64 bit libraries. The reason for this is that "… all Shell extension handlers are in-process Component Object Model (COM) objects."
So this means that on a 64 bit Windows, a 32 bit application cannot create a File Explorer extension, and vice versa.
Additionally, this would be Windows specific, and it would take a bit of work to implement.
Note: You can drag a directory on MovieScanner, and it will recursively read all valid files.
There may be a trick, not as elegant, but it will work by using the "sendto" option.
For this we need 2 things:
1) a shortcut to the MovieScanner.exe in
2) I have to modify MovieScanner to accept files or directories as parameters (I still have to do this).
I'll try to implement that (2) with the next release.