Tracking audio waveforms with Flash9 AS3

Actionscript 3.0 provides a new feature that uses ByteArray, Soundmixer.
The code is as follows:
function func (a:number) {
Return num * Math.sin (a);
}
function Drawfunction (func:function, Thickness:number, Color:number) {
Graphics.linestyle (thickness, color, 100);
Graphics.moveto (STAGE.STAGEHEIGHT/2-func) ((+ t)/20) * 20);
for (var i = i <= stage.stagewidth-30; i++) {
var fi = Stage.stageheight/2-func ((i + t++)/20) * 20;
Graphics.lineto (i, FI);
}
}
function Spectrum (event:event) {
Graphics.clear ();
Soundmixer.computespectrum (BA, True, 0);
num = ba.readfloat () * 10;
Drawfunction (func, 1, 0x0066cc);
}
var sound:sound = new sound ();
var Sound_channel:soundchannel;
var ba:bytearray = new ByteArray ();
var Num:number;
var t:number = 0;
Sound.load (New URLRequest ("Test.mp3"));
Sound_channel = Sound.play ();
This.addeventlistener (Event.enter_frame, Spectrum), please release the test with Flash 9/actionscript 3.0
Download (download)

PS: More cow effect please see http://theflashblog.com/?p=182
Online Help Documentation: http://livedocs.macromedia.com/flex/2/langref/package-summary.html