In my testing, I found several instances in my media collection where I had an old file (say standard definition, stereo sound) and an improved file (HD, surround sound).
I made these discoveries after my initial Infuse library scan, so Infuse found all the older files (perfectly, and as expected).
Once I discovered my improved files, I simply renamed the ‘new’ files the same as the old and overwrote the old files.
Subsequent invocations of ‘Scan for Changes’ did NOT update the resolution/audio information for these files. Going to an individual file and executing the ‘Edit Metadata’ command did update the information.
I guess I’m wondering what ‘Scan for Changes’ does, especially in comparison to ‘Refresh Metadata’ when executing those commands from the Library settings?