Had to look that ,mod up: ancient file extension for consumer video cams and Amiga. You will probably need to find some obscure video conversion app. Final Cut Pro X has been out for like five years. You've just now started to use it?
From the wiki:
The first version of the format was created by Karsten Obarski for use in the Ultimate Soundtracker; tracker software released for the Amiga computer in 1987.[1][2] The format has since been supported by hundreds of playback programs and dozens of other trackers.
The original version of the MOD format featured four channels of simultaneous audio playback, corresponding to the capabilities of the original Amiga chipset, and up to 15 instruments.
Later variations of the format have extended this to up to 32 channels and 31 instruments.
The format was designed to be directly playable on the Amiga without additional processing: for example, samples are stored in 8-bit PCM format ready to be played on the Amiga DACs, and pattern data is not packed. Playback required very little CPU time on an Amiga, and many games used MOD files for their background music.
A common misconception is that the magic number "M.K." in the 0x438 offset of MOD files are the initials of Mahoney and Kaktus, two prominent Amiga demomakers at the time, who played an important part in the popularity of the format. They in fact stand for the initials of Michael Kleps a.k.a. Unknown / DOC, another developer of the format.[3]