Hi,
It is decoded audio data bit hash eg. fingerprint.
To simply test Use one FLAC -> Decode to WAV -> Encode WAV to FLAC -> Decode that to WAV -> Compare files WAV Files and they should be same except maybe few bytes if metadata is changed, but in my tests they are bit perfectly same.

Thank you for that. I was under the impression that MM as analyzing the audio but it is really the filehash, correct?

Hi,
Try with this app https://apps.microsoft.com/store/detail ... BLGGH4RRR2

Well, I have files with the same artist, title, duration and size. I even went as far as reencoding them with the same application.
I would have uploaded a screenshot but there does not seem an easy way to do it.
Let's suppose they still have different fingerprint info. Is there a utility that can generate it so I could see for myself if it is really different?

Then you're duplicates may not be exact matches. Duplicate Content relies on audio fingerprint matches.

MM for some reason does not detect a lot of duplicates in the library. It does some but most of them does not. I wonder what could be a cause of it.

The "Analyze Files For Duplicates" option is checked.