As3 how to call and use an external class - actionscript-3

Question

I have this cool As3 MP3pitch package, which I got from here: http://blog.andre-michelle.com/2009/pitch-mp3/#more-483
package components
{
import flash.events.Event;
import flash.events.SampleDataEvent;
import flash.media.Sound;
import flash.net.URLRequest;
import flash.utils.ByteArray;
/**
* #author Andre Michelle (andre.michelle#gmail.com)
*/
public class MP3Pitch
{
private const BLOCK_SIZE: int = 3072;
private var _mp3: Sound;
private var _sound: Sound;
private var _target: ByteArray;
private var _position: Number;
private var _rate: Number;
public function MP3Pitch( url: String )
{
_target = new ByteArray();
_mp3 = new Sound();
_mp3.addEventListener( Event.COMPLETE, complete );
_mp3.load( new URLRequest( url ) );
_position = 0.0;
_rate = 1.0;
_sound = new Sound();
_sound.addEventListener( SampleDataEvent.SAMPLE_DATA, sampleData );
}
public function get rate(): Number
{
return _rate;
}
public function set rate( value: Number ): void
{
if( value < 0.0 )
value = 0;
_rate = value;
}
private function complete( event: Event ): void
{
_sound.play();
}
private function sampleData( event: SampleDataEvent ): void
{
//-- REUSE INSTEAD OF RECREATION
_target.position = 0;
//-- SHORTCUT
var data: ByteArray = event.data;
var scaledBlockSize: Number = BLOCK_SIZE * _rate;
var positionInt: int = _position;
var alpha: Number = _position - positionInt;
var positionTargetNum: Number = alpha;
var positionTargetInt: int = -1;
//-- COMPUTE NUMBER OF SAMPLES NEED TO PROCESS BLOCK (+2 FOR INTERPOLATION)
var need: int = Math.ceil( scaledBlockSize ) + 2;
//-- EXTRACT SAMPLES
var read: int = _mp3.extract( _target, need, positionInt );
var n: int = read == need ? BLOCK_SIZE : read / _rate;
var l0: Number;
var r0: Number;
var l1: Number;
var r1: Number;
for( var i: int = 0 ; i < n ; ++i )
{
//-- AVOID READING EQUAL SAMPLES, IF RATE < 1.0
if( int( positionTargetNum ) != positionTargetInt )
{
positionTargetInt = positionTargetNum;
//-- SET TARGET READ POSITION
_target.position = positionTargetInt << 3;
//-- READ TWO STEREO SAMPLES FOR LINEAR INTERPOLATION
l0 = _target.readFloat();
r0 = _target.readFloat();
l1 = _target.readFloat();
r1 = _target.readFloat();
}
//-- WRITE INTERPOLATED AMPLITUDES INTO STREAM
data.writeFloat( l0 + alpha * ( l1 - l0 ) );
data.writeFloat( r0 + alpha * ( r1 - r0 ) );
//-- INCREASE TARGET POSITION
positionTargetNum += _rate;
//-- INCREASE FRACTION AND CLAMP BETWEEN 0 AND 1
alpha += _rate;
while( alpha >= 1.0 ) --alpha;
}
//-- FILL REST OF STREAM WITH ZEROs
if( i < BLOCK_SIZE )
{
while( i < BLOCK_SIZE )
{
data.writeFloat( 0.0 );
data.writeFloat( 0.0 );
++i;
}
}
//-- INCREASE SOUND POSITION
_position += scaledBlockSize;
}
}
}
How can I include it into my "main" as3 file and use it? I can't just slap it into the same file, since the main file already has it's own package and class.
Essentially what I'm trying to do here is to load a sound file, play it, and change it's pitch in relation to the values what I have already.
Thanks in advance.

Answer 1

You have to create a folder with the same name as the package (here components) and put this class in it. Then from your main, import this class:
import components.MP3Pitch
You just have to instanciate this class and use it in your code:
var pitcher:MP3Pitch = new MP3Pitch("mymp3.mp3");
pitcher.rate = 2;

Answer 2

package {
import components.MP3Pitch;
public class Main extends Sprite
{
public function Main() {
new MP3Pitch("http://path-to-mp3-file.com/");
}
}
}