1/5/2011 10:01:04 AM

Title: Sound Record and Play at 8Khz, Recording is OK but Why it is not Playing

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Please refer to the question :
http://askmeflash.com/qdetail/1067/capturing-microphone-and-playing-at-lower-sampling-rate
For our project detail refer to :http://ganeshtiwaridotcomdotnp.blogspot.com/2010/12/text-prompted-remote-speaker.html
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we were initially planning to record the audio at 22 Khz but later we come to conclusion that processing of 22Khz data will be expensive..... and 8Khz will be enough... only 8000 samples per second of audio signal.
the audio is captured at 8Khz and uploaded to server (file bytearray) by modifying AIR's WavWriter class. the saved .wav file is played correctly. but when we are playing the captured byteArray in Client side it is not played correctly.
here is the code :

<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009" 
		 xmlns:s="library://ns.adobe.com/flex/spark" 
		 xmlns:mx="library://ns.adobe.com/flex/mx" width="230" height="95">
	<fx:Script>
		<![CDATA[
			private var mic:Microphone;
			public var byteArrayData:ByteArray;
			public var pcmArray:Array;
			private var snd:Sound;
			import mx.core.FlexGlobals;
			[Bindable] 
			private var micNames:Array = Microphone.names;//bind list of microphones to combo box
			private var rate:int=8;
			protected function recBtn_clickHandler(event:MouseEvent):void{
				if (event.currentTarget.selected == true){
					byteArrayData=new ByteArray();//byteArray variable to store recorded data
					mic = Microphone.getMicrophone(micNamesCombo.selectedIndex);//choose mic from combo list
					//set mic properties
					mic.setUseEchoSuppression(true);
					mic.rate=rate;
					mic.setSilenceLevel(0);
					//mic.setSilenceLevel(silenceLevel,timeOut);
					//set handlers
					mic.addEventListener(StatusEvent.STATUS, statusHandler);
					mic.addEventListener(SampleDataEvent.SAMPLE_DATA, getMicAudio);
					//change components' properties
					event.currentTarget.label = "Stop";
					ply_Btn.enabled=false;
				}
				else{
					//unset getMicAudio handler
					mic.removeEventListener(SampleDataEvent.SAMPLE_DATA, getMicAudio);
					event.currentTarget.label = "Record";
					ply_Btn.enabled=true;
				}
			}
			protected function statusHandler(event:StatusEvent):void{
				//if user denies to open microphone or not available or muted
				if (mic == null) {
					lblErr.text="Error on accessing microphone";	
				}
				if(mic.muted==true){
					lblErr.text="Your Microphone is Muted, unmute it";
				}
			}
			//writes sound data to bytearray
			private function getMicAudio(e:SampleDataEvent): void
			{	
				byteArrayData.writeBytes(e.data);
				//display byteArray length on label
				lblByteCount.text = String(byteArrayData.length);
			}

			 // plays sound

			protected function plyBtn_clickHandler(event:MouseEvent):void{
				if (event.currentTarget.selected == true){
					event.currentTarget.label = "Stop";
					byteArrayData.position = 0;//reset byteArray position to start
					snd = new Sound();
					snd.addEventListener(SampleDataEvent.SAMPLE_DATA, playRecorded);//start playing by invoking SampleDataEvent
					var channel:SoundChannel;//to play, create SoundChannel variable
					channel=snd.play();
					channel.addEventListener(Event.SOUND_COMPLETE, stopPlayback);//when playing is complete
				}
				else{
					event.currentTarget.label = "Play";
					snd.close();
				}
			}	
//<<<<<<<<<<<<<<<<<HERE IS THE PROBLEM>>>>>>>>>>>>>>>>>>>>
			private function playRecorded(e:SampleDataEvent): void{
				if (!byteArrayData.bytesAvailable > 0)//if end; return
					return;
				for (var i:int = 0; i < 8192/(44/rate); i++){
						var sample:Number = 0;
							if (byteArrayData.bytesAvailable > 0) 
								sample = byteArrayData.readFloat();
							//write sample, i.e., play
							for(var j:int=0; j<int((44.0/rate)*2);j++){//4 for 22 khz?for 8khz
								e.data.writeFloat(sample);
							}
					}
			}
//<<<<<<<<<<<<<<<<<WHAT IS THE SOLUTION >>>>>>>>>>>>>>>>>>>>
			private function stopPlayback(e:Event): void{
				ply_Btn.selected=false;
				ply_Btn.label="play";
			}
		]]>
	</fx:Script>
	<mx:ComboBox id="micNamesCombo" dataProvider="{micNames}" x="105" y="11" width="115" toolTip="List of Available Microphones on your computer"/>
	<s:ToggleButton id="rec_Btn" x="10" y="10" width="80" label="Record" click="recBtn_clickHandler(event);"/>
	<s:ToggleButton id="ply_Btn" x="10" y="42" width="80" label="Play" click="plyBtn_clickHandler(event);" enabled="false"/>
	<s:Label x="105" y="42" id="lblByteCount" width="116" height="21" fontSize="16"/>
	<s:Label x="10" y="70" id="lblErr" width="210" height="20" text="" verticalAlign="middle"/>
</s:Group>

We searched for the solution but could not find. And there was nothing mentioned on Adobe documentation. Anyway, Why the code is not working.... what is the actual problem? Please Help us.

1/6/2011 1:02:47 AM

1/6/2011 1:05:22 AM

1/6/2011 4:42:52 AM

1/6/2011 4:47:58 AM

8/17/2011 12:01:26 PM

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