This is a pure-Ruby MP3 metadata extractor. We use it to identify the bitrate and duration of songs that people upload to http://www.reverbnation.com .
It handles a bunch of things:
- ID3v1 tags
- ID3v2 tags (although it doesn't actually parse the frames)
- VBR files (with Xing headers)
- Multiple ID3v2 tags (because these exist in the wild)
Don't think of this as an example of good code. This is some of the most terrible, ugly, brutally hacky code I think I've ever written. I apologize to anyone who looks at it.