Anybody have experience with replacing the movie (.sfd) files in FA?

I've been hunting down tools that can convert .m1v files into .sfd and i've had no luck with getting any of them to work. There's some old tools on the FA wiki (sfdmux, TMPGEnc) but I can't tell if it's a compatibility issue with win10 or if i'm doing something wrong with the tools. I'd like to pretty up the loading screens and some cutscenes if I get ambitious.

When using sfdmux I can't get the .bat to find/open my .m1v files.
sfd 2.png