Need soution for equalizer in flex? - apache-flex

Question

I have developed a small application for testing 5 band equalizer in flex. I found the code in this link Flex Equalizer
The equalizer works fine.But i am not able to seek the desired position while playing the mp3 file.Following is my code....How to solve this problem?
import __AS3__.vec.Vector;
import mx.events.FlexEvent;
import spark.components.VSlider;
public static const BUFFER_SIZE:int = 8192;
public static const SAMPLE_RATE:int = 44100;
private var _Position:Number=0;
private var timer:Timer = new Timer(1000);
private const _soundURI:String = "testfile.mp3";
private var _out_snd:Sound = new Sound();
private const _eqL:EQ = new EQ();
private const _eqR:EQ = new EQ();
private var _loop_snd:Sound = new Sound();
// For storing dynamically created VSliders
private const _sliders_vect:Vector.<VSlider> = new Vector.<VSlider>();
private var _channel:SoundChannel = new SoundChannel();
private var _samples:ByteArray;
protected function view1_initializeHandler(event:FlexEvent):void
{
// TODO Auto-generated method stub
timer.addEventListener(TimerEvent.TIMER,timerFunction);
pgHolder.addEventListener(MouseEvent.CLICK,seekf);
setupEQ();
loadSound();
}
private function timerFunction(event:TimerEvent):void
{
_Position = _channel.position;
pgHolder.value=_Position;
}
private function seekf(event:MouseEvent):void
{
_channel.stop();
_Position = (pgHolder.contentMouseX/pgHolder.width)*_loop_snd.length;
startPlay();
}
private function loadSound():void
{
_Position=0;
_loop_snd.addEventListener(Event.COMPLETE, loadSoundComplete);
_loop_snd.addEventListener(IOErrorEvent.IO_ERROR, loadSoundError);
_out_snd.addEventListener(SampleDataEvent.SAMPLE_DATA, processSound);
_loop_snd.load(new URLRequest(_soundURI));
}
private function loadSoundComplete(event:Event):void
{
pgHolder.minimum=0;
pgHolder.maximum=_loop_snd.length;
timer.start();
startPlay();
}
private function startPlay():void
{
_channel=_out_snd.play(_Position);
}
private function loadSoundError(event:Event):void
{
trace("loadError");
}
// Create Sliders for changing EQ gain
private function setupEQ():void
{
var slider:VSlider;
for (var i:int = 0; i < _eqL.gains.length; i++) {
slider = new VSlider();
slider.x = (i * 35);
slider.y = 20;
slider.value = .9;
slider.maximum = 1;
slider.snapInterval=0.1;
slider.minimum = 0;
slider.addEventListener("change", changeEQHandler);
addElement(slider);
_sliders_vect[i] = slider;
}
var event:Event = new Event("change");
changeEQHandler(event);
}
private function processSound(event:SampleDataEvent):void
{
//trace("loading");
if(_Position>=_loop_snd.length)
{
_channel.stop();
}
_samples = new ByteArray();
var len:Number = _loop_snd.extract(_samples,BUFFER_SIZE);
var i:int=0;
var l:Number;
var r:Number;
if ( len < BUFFER_SIZE ) { // If end of MP3, start over
len += _loop_snd.extract(_samples,BUFFER_SIZE-len,0);
}
_samples.position = 0;
trace("len" + len + "//" + _channel.position + "//" +_samples.length);
while (i < BUFFER_SIZE) {
event.data.writeFloat(_eqL.compute(_samples.readFloat()));
event.data.writeFloat(_eqR.compute(_samples.readFloat()));
i++;
}
}
// Update EQ gains when sliders are changed
private function changeEQHandler(event:Event):void
{
var i:int = 0;
for(i = 0; i < _eqL.gains.length; i++){
_eqL.gains[i] = _sliders_vect[i].value * 2;
}
for(i = 0; i < _eqR.gains.length; i++){
_eqR.gains[i] = _sliders_vect[i].value * 2;
}
}
]]>
</fx:Script>
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<s:HSlider width="100%" height="100%" id="pgHolder">
</s:HSlider>

Answer 1

When you handle the slider change, I see you calculate the new _Position, but _Position is not bindable and its never used set set the player position.
This is just pseudo-code, but shouldn't you do something like:
private function seekf(event:MouseEvent):void
{
_channel.stop();
_channel.position = (pgHolder.contentMouseX/pgHolder.width)*_loop_snd.length;
_channel.start();
}
Just looking at your code, when you set _Position = _channel.position, you are simply getting a value, not a reference. My guess is that you need to set _channel.position