: If your device refuses to play it because of the double extension, try deleting the .m4v at the end so it just reads .mp4 . Most players will immediately recognize it.
: Certain digital video recorders (DVRs) save event clips under randomized database keys rather than chronological timestamps.
Based on the structure of the string, this is highly likely an automated, server-generated filename for a personal or private video file.
Because both MP4 and M4V are based on the MPEG-4 standard, you can access the file easily.