This app was mentioned in 2 comments, with an average of 1.00 upvote
Whoops, my mistake, I should have read the app description a bit more closely. Sorry about that.
Is it an option to just convert the files? Something like this should work.
Try converting to mp4 again or a different format, maybe it will rewrite to corrupted profile or cache whatever codec lingo it falls under, you can also try doing the same on pc, download a video converter see if that returns results.