OK - I managed to install and use ffmpeg, thanks to 2 Youtube videos. Unfortunately when trying the repair/copy it tells me:
moov atom not found. Invalid data found when processing input.
Chris - I had moderate success with one of these free ones, but cannot replicate my moderate success. Yep, doubled up the file as you suggested but cannot find my notes on which one and how I did it. The output was moderate, however, so I'm looking at something that works that someone may have experience with. Thanks for your input
