Best way to repair corrupt iPhone videos

I've found several corrupt iPhone videos. Not all - just some videos, so far during the span of a month or two.

What's the best way to repair them? I can play them (with some video corruption), but can't have them processed by iMovie. I found them by going through and doing a "month-by-month" movie of all pics/videos.

I've tried MPEG Streamclip - it'll process them, but doesn't do much with them. Opened and saved with Quicktime - didn't do anything. Anything else to try?