Cantata Rating Importer
If you’ve been using Cantata as your MPD client and would like to import all your Ratings into RompR, you can use the ‘Import Ratings From Cantata’ plugin.
All this does is to pull all the ratings you’ve created using Cantata, and add them to RompR’s database. This will overwrite any ratings you have created in RompR if the same tracks are rated in Cantata.
As Cantata is no longer under active development it doesn’t seem worthwhile to create any tool to export ratings from RompR. so this won’t happen.