將WasapiLoopbackCapture wav音頻流轉換爲MP3文件

Question

我能夠在WasapiLoopbackCapture（naudio）的幫助下捕獲揚聲器生成的系統音頻。但問題是它捕獲的wav文件和wav文件的大小非常大（幾乎10到15 MB /分鐘）。我必須捕捉2-3小時的音頻，這將會太高。 我正在尋找一種解決方案，將WAV流轉換爲MP3，然後將其保存到磁盤上，由WasapiLoopbackCapture捕獲。我嘗試了LAME.exe或其他解決方案，但沒有成功。任何工作代碼。

這裏是我的代碼：

private void button1_Click(object sender, EventArgs e){ 
    LoopbackRecorder obj = new LoopbackRecorder(); 
    string a = textBox1.Text; 
    obj.StartRecording(@"e:\aman.mp3"); 

} 

public class LoopbackRecorder 
{ 
    private IWaveIn _waveIn; 
    private Mp3WaveFormat _mp3format; 
    private WaveFormat _wavFormat; 


    private WaveFileWriter _writer; 
    private bool _isRecording = false; 


    /// <summary> 
    /// Constructor 
    /// </summary> 
    public LoopbackRecorder() 
    { 

    } 

    /// <summary> 
    /// Starts the recording. 
    /// </summary> 
    /// <param name="fileName"></param> 
    public void StartRecording(string fileName) 
    { 
     // If we are currently record then go ahead and exit out. 
     if (_isRecording == true) 
     { 
      return; 
     } 

     _fileName = fileName; 
     _waveIn = new WasapiLoopbackCapture(); 
     // _waveIn.WaveFormat = new WaveFormat(16000, 16 , 2); 
     _writer = new WaveFileWriter(fileName, _waveIn.WaveFormat); 

     _waveIn.DataAvailable += OnDataAvailable; 
     // _waveIn.RecordingStopped += OnRecordingStopped; 
     _waveIn.StartRecording(); 
     _isRecording = true; 
    } 




    private void OnDataAvailable(object sender, WaveInEventArgs waveInEventArgs) 
    { 
     if (_writer == null) 
     { 
      _writer = new WaveFileWriter(@"e:\aman.mp3", _waveIn.WaveFormat); 
     } 

     _writer.Write(waveInEventArgs.Buffer, 0, waveInEventArgs.BytesRecorded); 

     byte[] by= Float32toInt16(waveInEventArgs.Buffer, 0, waveInEventArgs.BytesRecorded); 

    } 

    private string _fileName = ""; 
    /// <summary> 
    /// The name of the file that was set when StartRecording was called. E.g. the current file being written to. 
    /// </summary> 
    public string FileName 
    { 
     get 
     { 
      return _fileName; 
     } 
    } 
} 

Answer 1

下面是一個使用NAudio.Lame（在控制檯應用程序）來捕獲從聲卡回送數據直接寫入到MP3文件的例子：

using System; 
using NAudio.Lame; 
using NAudio.Wave; 

namespace MP3Rec 
{ 
    class Program 
    { 
     static LameMP3FileWriter wri; 
     static bool stopped = false; 

     static void Main(string[] args) 
     { 
      // Start recording from loopback 
      IWaveIn waveIn = new WasapiLoopbackCapture(); 
      waveIn.DataAvailable += waveIn_DataAvailable; 
      waveIn.RecordingStopped += waveIn_RecordingStopped; 
      // Setup MP3 writer to output at 32kbit/sec (~2 minutes per MB) 
      wri = new LameMP3FileWriter(@"C:\temp\test_output.mp3", waveIn.WaveFormat, 32); 
      waveIn.StartRecording(); 

      stopped = false; 

      // Keep recording until Escape key pressed 
      while (!stopped) 
      { 
       if (Console.KeyAvailable) 
       { 
        var key = Console.ReadKey(true); 
        if (key != null && key.Key == ConsoleKey.Escape) 
         waveIn.StopRecording(); 
       } 
       else 
        System.Threading.Thread.Sleep(50); 
      } 

      // flush output to finish MP3 file correctly 
      wri.Flush(); 
      // Dispose of objects 
      waveIn.Dispose(); 
      wri.Dispose(); 
     } 

     static void waveIn_RecordingStopped(object sender, StoppedEventArgs e) 
     { 
      // signal that recording has finished 
      stopped = true; 
     } 

     static void waveIn_DataAvailable(object sender, WaveInEventArgs e) 
     { 
      // write recorded data to MP3 writer 
      if (wri != null) 
       wri.Write(e.Buffer, 0, e.BytesRecorded); 
     } 
    } 
} 

目前的NAudio.Lame包裝上的NuGet編譯爲86只有，因此請確保您的應用程序已設置爲定位該平臺。

Answer 2

要將音頻轉換成MP3上的蒼蠅，最簡單的方法之一是使用，讓您通過標準輸入傳遞音頻到LAME.exe的命令行選項。我描述瞭如何在this article中做到這一點。

您可能也有興趣Corey Murtagh創建了a LAME package for NAudio。我自己並沒有嘗試過，但它看起來應該也能完成這項工作。文檔是here。