'Making movies'. This corrupt video is result of recovery. Recovery may have been incorrect or file was already (partially) overwritten. In cases like this I always start by checking what's inside the file, whether it's a JPEG or whatever, sometimes you can extract complete files from the corrupt files. This time it's a MOV video file. And indeed we can extract a playable file + we can use the 'header' of that file to repair a orphaned mdat atom.