MP3 Diags 0.99.06.040

MP3 Diags 0.99.06.040 is considered to be a good-quality and helpful GUI-based application that allows end-users to identify issues with their MP3 files, fix some of the issues and make other changes, like adding track information. It also lets you "look inside" an MP3 file.

Unlike some programs that are designed to deal with a single topic (like fixing VBR headers or adding cover art), MP3 Diags is a one stop solution that identifies more than 50 different issues in MP3 files and provides the means to fix many of them (well, not everything is fixable; you can't make a 64kbps file sound like a 256kbps one.)
Major Features:

1. Adding / fixing track info, including album cover; information can be retrieved from several sources: Internet, clipboard, file name, local files, and (obviously) keyboard
2. Correcting files that show incorrect song duration
3. Correcting files in which the player cannot seek correctly
4. Converting characters for non-English names
5. Adding composer name to the artist field, for players that don't handle the composer field
6. Renaming files based on their fields
7. Changing word case for track info