Restoring playlist from `Music.app` backups is an arduous, manual mess.

[lgarron]

Splitting this out from https://github.com/lgarron/first-world/issues/110#issuecomment-1140427233

It's still really easy to delete a playlist with no practical way to restore it.

I have lots of backups of my iTunes/Music.app library. I export the XML format once per month by hand. However, I'm currently trying to restore a particular playlist (infuriatingly deleted due to the issue that led me to finally file #110), and it's a mess.

Using a backed-up Music Library.musiclibrary package:

• Even if my XML export were sufficiently up to date, there's no simple way to just re-import a particular playlist (although this would be feasible if I had just a particular playlist export). Reading the XML file by hand is a painful way to reconstruct the playlist, since playlist entries are stored using IDs. I've used tools to read the XML, but that sounds like a pretty onerous way to restore a single playlist.

• Opening the package from Finder doesn't work.

• Opening Music.app and pressing the Option key at startup does allow you to select a library file. However, it runs into this error:

  

• Signing out and/or deauthorizing Music.app does nothing to make that error go away. I think it's implying that you have to deauthorize all your device to roll back to a backup library, which sounds ludicrous.

• Trying to open the .musiclibrary package in a fresh user account result in this (note: in this screenshot, the current user account is the owner of the package and its contents, so write permissions shouldn't be the actual issue):

  

Apple doesn't have documentation for this. The closest is https://support.apple.com/en-us/HT201625, which:

• still refers to "iTunes" and iTunes Library.itl,
• talks about backing up and restoring your entire Mac rather than how to restore just the library, and
• otherwise documents the process specifically for "your PC" (Windows).

I'm going to look for tools to decode the contents of Music Library.musiclibrary (Library.musicdb in particular), we'll see how that goes. If that succeeds, it's probably only another 2-3 hours to actually reconstruct the playlist. 🤷

[lgarron]

I'm going to look for tools to decode the contents of Music Library.musiclibrary (Library.musicdb in particular), we'll see how that goes.

First step:

https://github.com/rinsuki-lab/musicdb-format/tree/master/HexFiend_BinaryTemplates

[lgarron]

• Trying to open the .musiclibrary package in a fresh user account result in this (note: in this screenshot, the current user account is the owner of the package and its contents, so write permissions shouldn't be the actual issue):

Okay, I tried this a few times and it finally worked.

Turns out that Finder was showing deceptive info about the file permissions, but I think that may have actually helped me. Specifically, I was able to get Music.app to load the database long enough to take some screenshots and also run "Export > Playlist", although the .m3u8 export ended up truncated and corrupted.