I have some files with rectangular cover art and I'd like to make the covers square. Is there a quick way to do this in MP3Tag? It looks like I might have to export the covers to files, run a script, and then import back?
A built-in cropping feature would be very handy, but I'm sure it would also be very niche.
It's available via the context menu on the cover window as Adjust.... If you want to include that in a reusable workflow, you can an Adjust Cover action.