Filemaker can return results about files in a container field, like cover art, track numbers, latitudes and longitudes of photos taken, etc.
But there isn't any way to natively edit these within Filemaker is there? Or even any plug ins?
Things such as cover art are usually still images saves as JPEG, GIF, TIFF or PNG. You can use FMP's container calculations to downsize still images while entering them into container fields.
There is a sample file that does this is several ways, but you may have to copy this link and paste it into the URL, as the redirect seems to fail today:
Retrieving data ...