If you have a large music collection scattered on different types of memory devices, from SD cards to hard drives or CD-ROMs, you must have at least once had problems with corrupted files, bad tagging or doubtful metadata. Since the MP3 format is still the most widely used and best supported when you don't want to carry around a bag of original CDs of your favorite bands, having a good MP3 tag editor and file repair tool is absolutely necessary.
There are many tools out there that can tackle the task of editing audio file metadata, and there is even minimal support for this in most audio players, but they aren't able to do advanced edits, embed the cover to the file or even repair some messed-up headers. For those kinds of problems, I find it better to just use MP3 Diags. While this isn't a tool for the novice user, spending a short time getting used to the concepts and the functionality bundled in this program can help you save a lot of time when you do the actual edits.
When you fire up MP3 Diags for the first time, you will be greeted with a session creation tool. Use it to pick the folders in which the program will look for MP3s, set a backup folder, choose the place where your settings will be stored and even manage the way in which multiple sessions will be handled. The backup folder acts like a safety net, because once you have committed your edits to a file, the only way to undo them is to reach for the copy that was automatically made in that folder.
Once you are comfortable with the setup you have made, click "OK" and MP3 Diags will start looking into your folders for some MP3s in need of attention. I only used two albums that add up to 25 songs and the scan took close to two minutes, but remember that this isn't your favorite audio player adding music to a playlist, the analysis that the files undergo is quite thorough.
The next window gives you the chance to enable a feature that automatically checks if a new version of the program is available. The detailed description of this procedure is a nice addition that lets you make sure that no unwanted operations will happen. I strongly recommend you to allow the checks, because MP3 Diags' developer is quite active and new versions are released frequently.
After those few initial configuration steps you will finally see the "business end" of this piece of software, where most of the editing and fixing takes place. The main window has a pretty simple design, with a row of icons on the top and three panes below it. One lists the files, the one in the middle can be set to display file information, notes or tag details, and the one below lists the file's tags or other data structures contained within. You will think that tag editing has nothing to do with this layout and you're right, because MP3 Diags is manly a file repair tool and advanced editor, but the tagging functions are there, make no mistake about it.
So, what kind of repairs can this application do? We counted 17 different functions that range from cleaning up tags that have a different encoding and display badly to repairing variable bitrate headers – a key clue that shows a file with this problem is the inability to skip through it. When you have multiple files that suffer from a common set of problems, you can group the fixes on four different quick access buttons that apply that group of operations with a single click.
The tag editor has its own dedicated window, which has a better layout for this kind of job. The file list is on the upper part of the window, while the lower section covers the details for the selected file. The album art, if any, is placed in between the two panes. What you will notice is that not all your files are listed. That is because the tagger works in one folder at a time, a mode of operation that is especially useful when you have grouped your albums that way. Should you be unsure of the specific details or even the spelling of the artist's name, the information retrieval functions from Discogs and MusicBrainz should come in handy. You can also do pattern editing and even mass tagging or renaming.
Next up on the toolbar is the normalization function. When applied to an album, it makes sure that all the songs in it have the same overall volume, so that one doesn't sound louder than the other. Doing this to a single file isn't all that useful, since there is no reference to compare it to.
An extra look to MP3 Diags' settings window is well worth it, as it allows you to change the way your files will be handled, what temporary folders should be used, and there are even some options that allow you to hide notes or transformations that you don't use. Also, there is a Quality tab in which you can set thresholds for file quality; if any, if your file is below them you will be notified about it. Certain options can really improve the usability of this program, like the custom coloring that can be applied to different tag types and the custom font settings.
MP3 Diags has a comprehensive on-line user manual that goes beyond the options of the program and even has details about the basics of the MP3 file structure and the technical terminology used. Also, when the function that you are trying to use has a mode of operation that isn't obvious, a note containing a short description and a link to the relevant documentation section will be shown. The Good
There is a wide range of options that can handle even the most complex editing tasks. MP3 Diags is very a customizable and powerful utility. The Bad
Aside from the well-structured and comprehensive documentation, novice users aren't catered for. A simplified interface or a "push-button" version of the program should exist. The Truth
It's an audiophile's dream come true. If you know what buttons to press, MP3 Diags will get the job done.