8/18/2010 11:11:19 PM

Title: capturing microphone and playing at lower sampling rate.

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i am having problem on capturing and playing microphone.
i am using eclipse(helios) with flex builder 4 plugin. and running on win7-64bit machine.
it works fine with capturing at 44 khz.
But when i capture the audio from microphone at lower rate less than 44, it captures it
sucessfully (size of byteArray becomes less for same duration of recording) but when i play, it speeds up and cannot be understood.
is there any way to play the captured sound at the same rate as it was sampled.
also i want to know the exact audio format of recorded audio in byteArray so that i can upload it to J2EE server and play it on server.

i have inserted my code below:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
			   xmlns:s="library://ns.adobe.com/flex/spark" 
			   xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"  width="445" height="274">
	<fx:Script>
		<![CDATA[
			private var mic:Microphone;
			private var rec:ByteArray;
			private var snd:Sound;
			protected function recBtn_clickHandler(event:MouseEvent):void{
				if (event.currentTarget.selected == true){
					event.currentTarget.label = "Stop";
					rec=new ByteArray();
					mic = Microphone.getMicrophone();
					mic.setUseEchoSuppression(true);
					mic.setSilenceLevel(10,5);
					mic.rate=16;//it creates 
					mic.addEventListener(SampleDataEvent.SAMPLE_DATA, getMicAudio);
					ply_Btn.enabled=false;
				}
				else{
					mic.removeEventListener(SampleDataEvent.SAMPLE_DATA, getMicAudio);
					event.currentTarget.label = "Record";
					ply_Btn.enabled=true;
				}
			}
			protected function plyBtn_clickHandler(event:MouseEvent):void{
				if (event.currentTarget.selected == true){
					event.currentTarget.label = "Stop";
					rec.position = 0;
					snd = new Sound();
					snd.addEventListener(SampleDataEvent.SAMPLE_DATA, playRecorded);
					var channel:SoundChannel;
					channel = snd.play();
					channel.addEventListener(Event.SOUND_COMPLETE, stopPlayback);
					
				}
				else{
					event.currentTarget.label = "Play";
					snd.close();
				}
			}	
			private function getMicAudio(e:SampleDataEvent): void
			{	rec.writeBytes(e.data);//capture
				lbl.text = String(rec.length);//show byteArray length
			}
			private function playRecorded(e:SampleDataEvent): void{
				//what must be done, for playing at same rate.
				if (!rec.bytesAvailable > 0) return;
				for (var i:int = 0; i < 8192; i++){//why 8192??
					var sample:Number = 0;
					if (rec.bytesAvailable > 0) sample = rec.readFloat(); 
					e.data.writeFloat(sample);
					e.data.writeFloat(sample);
				}
			}
			private function stopPlayback(e:Event): void{
				ply_Btn.selected=false;
				ply_Btn.label="play";
			}
			protected function changeValues():void{
				for(var i:int=0;i<rec.length;i++){
					if(rec[i]<100){
						rec[i]=rec[i]+3;//what should be done
					}	
				}
			}
		]]>
	</fx:Script>
	<s:Panel id="recordPanel" x="48" y="41" width="349" height="171" title="Sound Record and Play">
		<s:ToggleButton id="rec_Btn" x="20" y="25" width="80" label="Record" click="recBtn_clickHandler(event);"/>
		<s:ToggleButton id="ply_Btn" x="20" y="60" width="80" label="Play" click="plyBtn_clickHandler(event);" enabled="false"/>
		<s:Label id ="lbl" x="176" y="23" width="165" height="48" fontSize="20" fontFamily="Courier New" verticalAlign="middle"/>
		<s:Button x="198" y="91" label="Change Value +30" click="changeValues()"/>
	</s:Panel>
</s:Application>

8/20/2010 7:26:56 AM

8/23/2010 1:43:35 PM

8/24/2010 6:29:47 AM

8/24/2010 6:39:13 AM

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