This tool is designed to correct MP3 files where the text content has been corrupted by using the incorrect character set. You will often find this happening with MP3s which have Chinese text content (GB2312), despite these fields only supporting ISO-8859-1 or UTF-16.
This current version is very unpolished, but is being released as is in the hopes that this can help someone in its current state. I do plan on improving it, but that is all down to me finding the time to do so.
To use it you will need to first extract the zip and then open a command prompt to within the extracted folder. There, using ant type
The program should compile and then launch. From there select the folder containing the misencoded MP3 files. You can now work out what the necessary magic is to correct the text values. Check the 'apply' box for each file you want to apply the changes to, and then on closing the window you will be prompted to save the changes.[ source ]