Silverlight中调用麦克风模拟录音机设备，存储为WAV音频

  
  

   
   public
   
    
   
   class
   
    WavAudioSink:AudioSink
{

   
   //
   
    设置需要记录的内存流
   
   

   
   private
   
    MemoryStream _stream;

   
    设置当前的音频格式
   
    AudioFormat _format;


   
    Stream backingStream
 {

   
   get
   
    { 
   
   return
   
    _stream; }
 }


   
    AudioFormat CurrentFormat
 {

   
    _format; }
 }


   
   protected
   
   override
   
   void
   
    OnCaptureStarted()
 {
 _stream 
   
   =
   
   new
   
    MemoryStream(
   
   1024
   
   );
 }


   
    OnCaptureStopped()
 {
 }


   
    OnFormatChange(AudioFormat audioFormat)
 {

   
   if
   
    (audioFormat.WaveFormat 
   
   !=
   
    WaveFormatType.Pcm)

   
   throw
   
    InvalidoperationException(
   
   "
   
   WavAudioSink只支持PCM音频格式
   
   "
   
   );

 _format 
   
    audioFormat;
 }


   
    OnSamples(
   
   long
   
    sampleTime,
   
    sampleDuration,

   
   byte
   
   [] sampleData)
 {

   
    新的音频数据到达，将它们写入流
   
    _stream.Write(sampleData,
   
   0
   
   ,sampleData.Length);
 }
}
  
  

  
  

   
    SaveWAVHelper
 {

   
   static
   
    SavePcmToWav(Stream rawData,Stream output,AudioFormat audioFormat)
 {

   
    Argumentexception(
   
   Only PCM coding is supported.
   
   );

 BinaryWriter bwOutput 
   
    BinaryWriter(output);


   
    -- RIFF 块
   
    bwOutput.Write(
   
   RIFF
   
   .tocharArray());

   
    包的总长度

   
    计算的数据长度加上数据头的长度没有数据

   
    写数据(44 - 4 ("RIFF") - 4 (当前数据))
   
    bwOutput.Write((
   
   uint
   
   )(rawData.Length 
   
   +
   
    
   
   36
   
   ));
 bwOutput.Write(
   
   WAVE
   
   .tocharArray());


   
    -- FORMAT 块
   
   fmt 
   
    FORMAT 块的长度 (Binary,总是 0x10)
   
   )
   
   0x10
   
   );

   
    总是 0x01
   
   ushort
   
   0x01
   
    通道数( 0x01=单声道,0x02=立体声)
   
   )audioFormat.ChAnnels);

   
    采样率 (Binary,Hz为单位)
   
   )audioFormat.SamplesPerSecond);

   
    字节每秒
   
   )(audioFormat.bitsPerSample 
   
   *
   
    audioFormat.SamplesPerSecond 
   
    
 audioFormat.ChAnnels 
   
   /
   
   8
   
   ));

   
    每个样品字节: 1=8 bit 单声道,2=8 bit 立体声 or 16 bit 单声道,4=16 bit 立体声
   
    audioFormat.ChAnnels 
   
    每个样品字节
   
   )audioFormat.bitsPerSamplE);


   
    -- DATA 块
   
   data
   
    DATA数据块的长度
   
   )rawData.Length);

   
    原始PCM数据如下

   
    复位rawData地位，记住它的原点位置

   
    恢复底。
   
    originalRawDataStreamPosition 
   
    rawData.Position;
 rawData.Seek(
   
   .begin);

   
   追加到输出流中的所有数据从rawData流
   
   [] buffer 
   
   [
   
   4096
   
   ];

   
   int
   
    read; 

   
    循环读取字节数据
   
   while
   
    ((read 
   
    rawData.Read(buffer,0)">)) 
   
   >
   
   )
 {
 bwOutput.Write(buffer,read);
 }

   
   开始写入数据
   
    rawData.Seek(originalRawDataStreamPosition,SeekOrigin.begin);
 }
}
  
  

  
  

   
   <
   
   Grid x:Name
   
   =
   
   LayoutRoot
   
    BACkground
   
   White
   
   Button Content
   
   开始录制
   
    Height
   
   28
   
    HorizontalAlignment
   
   Left
   
   
 Margin
   
   30,15,0
   
    Name
   
   btnRecord
   
    VerticalAlignment
   
   Top
   
   
 Width
   
   71
   
    Click
   
   btnRecord_Click
   
   />
   
   停止录制
   
   150,0)">btnStopRecord
   
   btnStopRecord_Click
   
   保存音频
   
   268,0)">btnSaveWav
   
   btnSaveWav_Click
   
   </
   
   Grid
   
   >
  
  

  
  

   
   partial
   
    MainPage : UserControl
 {

   
    MainPage()
 {
 InitializeComponent();

 btnRecord.IsEnabled 
   
   true
   
   ;
 btnStopRecord.IsEnabled 
   
   false
   
   ;
 btnSaveWav.IsEnabled 
   
   ;
 }


   
   声明私有变量
   
    WavAudioSink _wavSink;

   
    Capturesource _capturesource;

   
    SaveFileDialog _saveFileDialog 
   
    SaveFileDialog() 
 { Filter 
   
   Audio files (*.wav)|*.wav
   
    };


   
    btnRecord_Click(
   
   object
   
    sender,RoutedEventArgs E)
 {


   
   初始化_capturesource
   
    var audioDevice 
   
    CaptureDeviceConfiguration.GetDefaultAudioCaptureDevice();
 _capturesource 
   
    Capturesource() { AudioCaptureDevice 
   
    audioDevice };


   
   有默认设置的设备且可以用来录制音频
   
    (CaptureDeviceConfiguration.AllowedDeviceAccess 
   
   ||
   
   
 CaptureDeviceConfiguration.requestDeviceAccess())
 {

   
   判断当前没有开始录制音频
   
    (_capturesource.State 
   
   ==
   
    CaptureState.Stopped)
 {

   
   初始化WavAudioSink
   
    _wavSink 
   
    WavAudioSink();
 _wavSink.Capturesource 
   
    _capturesource;

   
   开始录制音频
   
    _capturesource.Start(); 

 }
 }


 btnRecord.IsEnabled 
   
    btnStopRecord_Click(
   
   E)
 {

   
   如果当前状态为开始录制，则停止录制
   
    CaptureState.Started)
 {
 _capturesource.Stop();
 }


 btnRecord.IsEnabled 
   
    btnSaveWav_Click(
   
    (_saveFileDialog.ShowDialog() 
   
   )
 {

   
   ;
 }

   
   保存Wav文件
   
    Stream stream 
   
    _saveFileDialog.openFile();
 SaveWAVHelper.SavePcmToWav(_wavSink.backingStream,stream,_wavSink.CurrentFormat);

 stream.Close();

 messageBox.Show(
   
   你的音频已经保存
   
   );


 btnRecord.IsEnabled 
   
   ;
 }
}