Can getID3 get the data of the mp3 file that is being input for FFT?

I want to compare two pieces of music to find similarities. But I don't really understand what Fast Fourier Transform is. I don't even know the parameter of the FFT function (from https://gist.github.com/mbijon/1332348 ).

My questions:

• What are the parameters of the FFT function?
• Does getID3 function provide these parameters?
• If not, how can I get these parameters?

Here is my code.

<?php
    require_once('assets/getID3/getid3/getid3.php');
    require_once('FFT.php');
    $getID3 = new getID3;
    $ThisFileInfo = $getID3->analyze("music.mp3");
    $bit_rate = $ThisFileInfo['audio']['bitrate'];
    var_dump($bit_rate);
?>