Flex手机项目 - 调用麦克风录音并播放

2015-01-06 发布：hangge 阅读：1098
在AS3的移动项目中，使用Microphone类能通过设备的麦克风来记录音频流。
下面是一个使用麦克风录音并播放的demo，效果图如下：
代码如下：
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<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx"
                       title="麦克风测试"
                       creationComplete="onCreationComplete()">
 
    <fx:Script>  
        <![CDATA[ 
            import flash.events.SampleDataEvent;
            import flash.media.Microphone;
            import flash.media.Sound;
            import flash.utils.ByteArray;
             
            import mx.collections.ArrayCollection; 
             
            private var microphone:Microphone; 
            private var isRecording:Boolean = false; 
            private var soundByteArray:ByteArray; 
            private var soundObj:Sound; 
 
            /**
             * 页面初始化
             */
            private function onCreationComplete():void
            { 
                //加载麦克风列表
                soundCaptureDevices.dataProvider = new ArrayCollection(Microphone.names);
                soundCaptureDevices.selectedIndex = 0;
            } 
             
            /**
             * 开始录音
             */
            private function startRecording():void
            { 
                startBtn.enabled = false;
                stopBtn.enabled = true;
                playBtn.enabled = false;
                 
                soundByteArray = new ByteArray();
                 
                microphone = Microphone.getMicrophone(soundCaptureDevices.selectedIndex);
                microphone.addEventListener(SampleDataEvent.SAMPLE_DATA, onSampleData); 
                microphone.rate = 44; //麦克风捕获声音采样速率
                microphone.gain = 100; //麦克风在传输音频信号之前需要倍增音量
                //设置应该考虑为声音的最小输入音量水平，以及静默实际开始之前的静音时间量
                microphone.setSilenceLevel(0, 1000); 
            } 
             
            /**
             * 停止录音
             */
            private function stopRecording():void
            { 
                startBtn.enabled = true;
                stopBtn.enabled = false;
                playBtn.enabled = true;
                 
                microphone.removeEventListener(SampleDataEvent.SAMPLE_DATA, onSampleData); 
            } 
             
            /**
             * 录音中-录音数据持续接收响应
             */
            private function onSampleData(micData:SampleDataEvent):void
            { 
                //持续记录音频流
                soundByteArray.writeBytes(micData.data); 
            } 
             
            /**
             * 开始播放录音
             */
            private function playRecording():void
            { 
                var trans:SoundTransform = new SoundTransform(1, -1); 
                startBtn.enabled = false;
                soundByteArray.position = 0;
                soundObj = new Sound(); 
                soundObj.addEventListener(SampleDataEvent.SAMPLE_DATA, playSound); 
                soundObj.play(0, 1, trans); 
            } 
             
            /**
             * 录音播放中
             */
            private function playSound(e:SampleDataEvent):void
            {
                if (!soundByteArray.bytesAvailable > 0) 
                {
                    startBtn.enabled = true;
                    stopBtn.enabled = false;
                    playBtn.enabled = false;
                    return; 
                }
                 
                for (var i:int = 0; i < 8192; i++) 
                { 
                    var audioSample:Number = 0; 
                     
                    if (soundByteArray.bytesAvailable > 0) 
                    {
                        audioSample = soundByteArray.readFloat(); 
                    }
                     
                    //调用writeFloat()方法两次是为了音频数据采样能同时命中左声道和右声道
                    e.data.writeFloat(audioSample); 
                    e.data.writeFloat(audioSample); 
                }
            }
             
        ]]> 
    </fx:Script> 
     
    <s:layout>
        <s:VerticalLayout paddingLeft="20" paddingRight="20" paddingBottom="20" paddingTop="20"/>
    </s:layout>
 
    <s:VGroup width="437" gap="20" horizontalAlign="center">
        <s:Label id="description" text="选择一个麦克风并开始录音..." height="30"/>
         
        <s:ComboBox id="soundCaptureDevices" width="397" height="55"
                    textAlign="center" focusEnabled="false"/>
         
        <s:HGroup width="437" gap="20" horizontalAlign="center">
         
            <s:Button id="startBtn" label="录音" chromeColor="#51B22F" click="startRecording()"/>  
             
            <s:Button id="stopBtn" label="停止" chromeColor="#CB0909" click="stopRecording()"
                      enabled="false"/>  
             
            <s:Button id="playBtn" label="播放" click="playRecording()" enabled="false"/>
             
        </s:HGroup>
             
    </s:VGroup>
</s:View>