AtomicParsley is described as 'lightweight command line program that can read and set iTunes-style metadata tags in MPEG-4 files & 3gp assets in 3GPP/3GPP2 files' and is an app in the Video & Movies category. There are three alternatives to AtomicParsley for Mac, Windows and Windows S. The best alternative is iFlicks. It's not free, so if you're looking for a free alternative, you could try Metaz.
iFlicks is the best and most complete video and metadata handling solution available for macOS. There is no easier way to add you video files to iTunes or Plex, so you can watch them on your iOS devices or third party media players.
MyMeta is a Windows 8 / Windows RT App for editing metadata and artwork on MP4, M4V and MOV media files. MyMeta allows you to tag all your media files so that their information appears correctly in your favorite media player or streaming device.