Editing MP3 Metadata

[Darius1968]

How is this done in IMatch? 

[Mario]

Can't. ExifTool does currently not provide write-back for MP3.
You need to use a dedicated MP3 editor to do that.

[Darius1968]

Okay.  And, if I select multiple MP3 files and have the Metadata panel open to examine the "Track" value, for instance, but the same song has different values for the track, where the Metadata panel displays "(multiple values)", then is there a way to have the panel be able to enumerate through the selected files one-by-one so that each value can be evaluated separately, or must I just select one at a time? 

Also, I did use another application just now to modify the "Track" for seven files, while IMatch was running.  IMatch did recognize that those files had been modified, and at this point started its process of updating the metadata for those files.  However, it seems to take so long for the update to complete.  Is this normal? 

[Mario]

then is there a way to have the panel be able to enumerate through the selected files one-by-one so that each value can be evaluated separately, or must I just select one at a time? 

No. IMatch will not enumerate different values for the same tag if multiple files are selected.

Also, I did use another application just now to modify the "Track" for seven files, while IMatch was running.  IMatch did recognize that those files had been modified, and at this point started its process of updating the metadata for those files.  However, it seems to take so long for the update to complete.  Is this normal?

How long is 'long'?
If you attach a log file I can see how long it takes, exactly.

IMatch does not immediately process files when it receives "file modified" from Windows. Because some applications keep files locked for a few seconds after updating them. Or there may be more changes in the folder to come. So it takes about 5 seconds after the last "something in this folder has changed" before IMatch starts to rescan. So there may be a delay between you press "Save" in another application and before IMatch reads the changes.

When a MP3 file is changed, IMatch has to reload the metadata via ExifTool. It also has to extract the thumbnail (may have changed), update the cache image, visual query data etc. Reloading an MP3 file also invalidates some of the data-driven categories, collections and other internal states (e.g. the history for the file). All this has to performed.

On my old system, ingesting 10 MP files takes 3.3 seconds to extract and import the metadata, and 1.2 seconds for importing other data, creating and storing thumbnails and cache images. So about 4.5 to 5 seconds for 10 files. Forced rescan.