Reading MP3 ID3 Tags in Native PHP

This week I went crazy about file formats. I tried to understand specifications of many popular formats like MP3, FLV, PDF. Its amazing to see that no matter how complex these technologies are or the algorithms they use to store media efficiently, at the lower level it is just a clever arrangement of bits that makes sense and with a bit of experimentation and hacking around MP3 format (a Hex Editor is a invaluable tool in this), I was able to read them in PHP without using any extension. The source has been put on GitHub.