I'm struggling with converting some .mp3 files with apparently some greek character encoding to universal readable unicode. First of all I don't know which format was chosen. And the problem is that even mp3tag doesn't display the tags correctly. Look:
On the left you see the file browser with the file names for comparison. So should the id3 tags look like.
I haven't done any editing in mp3tag. The files are shown like that without me having done anything.
Setup: mp3tag on OS X 10.10 Yosemite with Wine
(if that's the issue it would be no problem to get access to a Win 7 / 8 or 10 machine)
MP3diags has a function that converts strings to unicode under the assumption of a certain code page.
And foobar, I think, has also such a function.
Then again: which OS are you using? I think XP lacked a couple of screen font characters to display all characters correctly.