I've got some video files I needed to add some meta data to and needed a quick and easy way to do it.
This is when I came across MetaX.
MetaX
https://www.macupdate.com/app/mac/24994/metax
Download: https://www.macupdate.com/download/24994/MetaX-2.4.6.dmg
This is no longer actively developed.
Windows: http://www.danhinsley.com/metax/metax.html
MetaZ
https://www.macupdate.com/app/mac/36029/metaz
Download: https://www.macupdate.com/download/36029/MetaZ-1.0a15.zip