moov atom not found
If ffmpeg gives you this error when encoding a video:
moov atom not found
Use AtomicParsley (Windows) to fix your atoms:
AtomicParsley myVideo.mp4 -P
The -P flag purges some meta data out of your video that you probably didn't know about or care about. You can also use AtomicParsley to set meta data -- artist, album, etc.
See: AtomicParsley --longhelp
AtomicParley is a simple to use command line utility. You'll be encoding with ffmpeg in no time.