I want to clean up my library. Going to change the metadata first, then want to change the file name of all to ARTIST - TITLE. But I want to simultaneously preserve the playlists I have built.
How can I let mp3tag edit multiple playlists in .m3u format so that they get updated with the new file names?
I also wanted to put them in a proper folder structure for the first time which I saw was possible in the FAQ. But .m3u files also have the file location as info, so I'd need an option to update the file location in the .m3u file as well.
I'm afraid that you have the sequence backwards. You say that you "want to simultaneously preserve the playlists I have built." However, once you have changed the filenames on disk, your old playlists are worthless. You cannot load invalid file names into Mp3tag, therefore you cannot edit them here. You would need a text editor and a lot of patience.
Better to load your old, valid playlists into Mp3tag one by one and then edit their file names and tags to suit your new naming schemes. That way you are always working with valid file names. At the end, use File|Playlist to create an updated version of each playlist. Then clear Mp3 tag and load the next old playlist.
Once you have this process working then you can look through the Help docs and the old posts here for tips on batch renaming of files, folders, and tags. There are zillions of them.
Also, consider adding a custom tag with a unique name for each playlist. That would enable you to load and modify more than one playlist at a time. You could even add sequential numbers to the playlist names to preserve the original track order. Then, at the end, you could sort on the playlist name tag to enable you to recreate each original group in a new playlist. Then you would use the File|Playlist (selected files) command for each sorted group.
In addition to the basic procedure that @Doug_Mackie outlined, I would suggest that you save the playlist name in a user-defined field - and perhaps even the postion number:
Convert>Tag-Tag for MYPLAYLIST
Format string: playlistname $num(%_counter%,2)
where you substitute playlistname with the real name.
If you have a file that appears in several playlists, then append the field MYPLAYLIST with the next name in a similar way.
Then you rename the files and filter for the saved playlist names and reconstruct the playlists with the new names.
Okay, yours seems like the better route because I have titles saved in multiple playlists. So what you seem to suggest is create my own tag for playlist location and at the end rebuild the playlists with my newly created tag. What I don't understand is:
When I try to open the m3u file with mp3tag it throws an error, saying it doesn't have access to every single file in the playlist. Where do the playlists have to be saved so mp3tag knows where the files are?
Could you explain that a bit further, I don't really get what you mean by that. Just create another custom tag with a unique playlist name? In the end I'd have 18 unique tags each for the possibility of the file being in one of them. Is there an easy way to delete those at the end?
This would mean what it says: the referenced file does not exist.
Once you have the playlist name stored in a user-defined tag field, you can filter for that data and (if the number is there) sort by it.
Once you are done with the renaming, simply load all the files, select them and press Alt-T to open the extended tags dialogue where you will see all the fields in all the files and where you can delete the fields you don't want.
If you go the way with the user-defined field and you have the requirement to record the membership of a file in several playlists, then I would suggest that you name user-defined field with what the playlist is called and you save only the position number to that field.
With a filter like
you will see all the files from that playlist. And with an added column that shows the number from that field, you can sort the files rename the files and in the end overwrite the playlist with the new contents.
Playlists have a property that we have not yet mentioned: whether or not they have to be kept in the same folders as the files they reference. When playlists are written without paths, then players and Mp3tag will automatically add the path of the playlist folder to each music file name. But when a full path is included in a playlist entry, then that path will be used by players and by Mp3tag.
If an MRU file contains only full paths, it does not matter what folder it is saved in, as long as the contained paths are valid.
So, if (and only if) a "dead" playlist lacks full paths, then try moving its MRU file back into its original music folder (or a re-creation of it), at least temporarily. That should enable you to load and edit the music files in Mp3tag.
If the original folder is unavailable and/or the MRU file contains bad paths, then all I can suggest is to edit the MRU paths with a text editor.