If you are curious about the structure of MP3 file, please take a look at this:
MP3 file is divided into a small blocks – frames. Each frame has constant time length 0.026 sec.
But size of one frame (in Bytes) varies according to bitrate. Eg. for 128kbps it is (normally) 417 Bytes and for 192kbps 626 Bytes.
The first 4 Bytes of each frame is frame header and the rest is audio data…
I have a strong felling that I’ll mess with this soon.