3 Replies Latest reply: Feb 14, 2013 10:44 AM by BJ4Rock
BJ4Rock Level 1 Level 1 (0 points)

Hi, after having spent hours adding composers to tracks (not realizing doing so while iTM was syncing was a bad idea) and seeing them vanish later, I truly want to understand how Match views meta-data (so I can possibly restore the hours' worth of work from Time Machine).

 

Here's what I do understand:

 

  • When I make changes to meta-data on the "master computer" (the one where the library resides), iTM will sync those changes to iCloud and propagate the changes to other computers and devices (although sometimes this seems to take quite some time)
  • I've also confirmed that I can use any other computer linked to my Apple ID and with iTM turned on to edit meta-data, even without having downloaded the track to these computers, and they will still be synced to the cloud copies and flushed through to other computers and devices, even the "master computer"

 

However, what I don't understand is which criteria iTM applies to determine which is the "master" meta-data to keep and which to overwrite. Some examples of cases:

 

  • For the same track, I edit the meta-data on the master computer and my wife edits the same data from her computer, creating conflicts within the the track information. Which of the edits will iTM keep and why?
  • I edit a track while the iTM update is in progress (which is the troublesome situation many have seen), meaning the meta-data on my master computer is newer than those in the cloud. Still, iTM considers the cloud data to take presedence and syncs these back to the computer.

 

Some criteria I could imagine are used:

 

  • The newest of conflicting data would be kept
  • The "master computer" would rule the others
  • Cloud data would be considered master

 

But it seems none of these consistently apply, and that's what's so frustrating...

  • BJ4Rock Level 1 Level 1 (0 points)

    And just to complete my question: My hope was that I could restore the iTunes library file from a couple of weeks ago, when the meta-data contain the composer data I've spent so much time adding, and have these sync to the cloud. When I try this, iTM overrides these data and replace them with the cloud's empty composer fields (at least for most tracks, again no consistency that I can see).

     

    If time is the criterion, i.e., the latest edit is kept, I can understand that iTM sees the restored library file as older and thus flushes the cloud data back down. My next idea is; first turning off iTM, if I restore the library file, then use one of Doug's scripts to append a space character at the end of all composer fields, then iTM should see those edits as newer?

     

    Afraid to mess too much with the library and risk losing more than I already have, I truly want to understand how iTM works before proceeding. So, any insights would be much appreciated!

  • Michael Allbritton Level 6 Level 6 (16,785 points)

    In general, iTunes Match considers "the cloud" to contain the "master" data.

     

    BJ4Rock wrote:

     

    However, what I don't understand is which criteria iTM applies to determine which is the "master" meta-data to keep and which to overwrite. Some examples of cases:

     

    • For the same track, I edit the meta-data on the master computer and my wife edits the same data from her computer, creating conflicts within the the track information. Which of the edits will iTM keep and why?

    iTM will keep the most recent change in the cloud and push it out to all the devices. So whichever of you finishes last "wins."

     

    BJ4Rock wrote:

     

    • I edit a track while the iTM update is in progress (which is the troublesome situation many have seen), meaning the meta-data on my master computer is newer than those in the cloud. Still, iTM considers the cloud data to take presedence and syncs these back to the computer.

    Yes, this is correct, unfortunately. Any changes to ID3 tags made while the service is actively scanning your library, or if there is an interuption in the connection between iTunes and the cloud servers will be ignored the next time the connection is re-established and the data from the cloud will be pushed to your computer.

     

    What you and I might consider the "master" library (ie: our iTunes library on our computer) is not in the case of iTunes Match. It is only a "client."

  • BJ4Rock Level 1 Level 1 (0 points)

    If someone else should have the problem of lost metadata edits, I can confirm that my proposed approach works: Restore the library file from Time Machine backup, keep Match turned off, make a small change in a field, e.g., add a space in the comment field. Then your local data were last updated, so when you turn on Match, these changes will be uploaded...