NAudio-實時拆分和合並波形

Question

我正在使用多輸入聲卡，我想實現多個輸入的現場混音。 所有輸入都是立體聲的，因此我需要首先將它們拆分，混合選擇的通道並將其作為單聲道流提供。

目標將是這樣的混合Channel1 [left] + Channel3 [right] + Channel4 [right]->單流。

我已經實現了這樣的流程鏈：

1） WaveIn- >為每個通道創建BufferedWaveProvider- >使用wavein.DataAvailable + = {buffwavprovider [channel] .AddSamples（...） ...向每個BufferedWaveProvider添加樣本（僅是當前通道的樣本）一個包含多個BufferdWaveProvider的漂亮列表。 此處的分割音頻部分已正確實現。

2）選擇多個BufferedWaveProviders並將它們提供給MixingWaveProvider32 。 然后創建一個WaveStream（使用WaveMixerStream32和IWaveProvider ）。

3）MultiChannelToMonoStream接收該WaveStream並生成混音。 這也有效。

但是結果是，音頻被切碎了。 就像緩沖區有些麻煩...。

這是解決此問題的正確方法，還是周圍有更好的解決方案？

編輯-添加代碼：

public class AudioSplitter
   {
      public List<NamedBufferedWaveProvider> WaveProviders { private set; get; }
      public string Name { private set; get; }
      private WaveIn _wavIn;
      private int bytes_per_sample = 4;

      /// <summary>
      /// Splits up one WaveIn into one BufferedWaveProvider for each channel
      /// </summary>
      /// <param name="wavein"></param>
      /// <returns></returns>
      public AudioSplitter(WaveIn wavein, string name)
      {
         if (wavein.WaveFormat.Encoding != WaveFormatEncoding.IeeeFloat)
            throw new Exception("Format must be IEEE float");


         WaveProviders = new List<NamedBufferedWaveProvider>(wavein.WaveFormat.Channels);

         Name = name;
         _wavIn = wavein;
         _wavIn.StartRecording();
         var outFormat = NAudio.Wave.WaveFormat.CreateIeeeFloatWaveFormat(wavein.WaveFormat.SampleRate, 1);

         for (int i = 0; i < wavein.WaveFormat.Channels; i++)
         {
            WaveProviders.Add(new NamedBufferedWaveProvider(outFormat) { DiscardOnBufferOverflow = true, Name = Name + "_" + i });
         }

         bytes_per_sample = _wavIn.WaveFormat.BitsPerSample / 8;
         wavein.DataAvailable += Wavein_DataAvailable;
      }


      /// <summary>
      /// add samples for each channel to bufferedwaveprovider
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void Wavein_DataAvailable(object sender, WaveInEventArgs e)
      {
         int channel = 0;
         byte[] buffer = e.Buffer;
         for (int i = 0; i < e.BytesRecorded - bytes_per_sample; i = i + bytes_per_sample)
         {
            byte[] channel_buffer = new byte[bytes_per_sample];

            for (int j = 0; j < bytes_per_sample; j++)
            {
               channel_buffer[j] = buffer[i + j];
            }

            WaveProviders[channel].AddSamples(channel_buffer, 0, channel_buffer.Length);

            channel++;

            if (channel >= _wavIn.WaveFormat.Channels)
               channel = 0;

         }

      }
   }

為每個通道使用Audiosplitter會提供一個緩沖波提供者列表（單32位浮點數）。

 var mix = new MixingWaveProvider32(_waveProviders);
 var wps = new WaveProviderToWaveStream(mix);
 MultiChannelToMonoStream mms = new MultiChannelToMonoStream(wps);

 new Thread(() =>
  {
     byte[] buffer = new byte[4096];

     while (mms.Read(buffer, 0, buffer.Length) > 0 && isrunning)
     {


        using (FileStream fs = new FileStream("C:\\temp\\audio\\mono_32.wav", FileMode.Append, FileAccess.Write))
        {
           fs.Write(buffer, 0, buffer.Length);
        }

     }
  }).Start();

Answer 1

還有一些空間需要優化，但是基本上可以完成工作：

  private void Wavein_DataAvailable(object sender, WaveInEventArgs e)
      {
         int channel = 0;
         byte[] buffer = e.Buffer;

         List<List<byte>> channelbuffers = new List<List<byte>>();
         for (int c = 0; c < _wavIn.WaveFormat.Channels; c++)
         {
            channelbuffers.Add(new List<byte>());
         }

         for (int i = 0; i < e.BytesRecorded; i++)
         {
            var byteList = channelbuffers[channel];

            byteList.Add(buffer[i]);

            if (i % bytes_per_sample == bytes_per_sample - 1)
               channel++;

            if (channel >= _wavIn.WaveFormat.Channels)
               channel = 0;
         }

         for (int j = 0; j < channelbuffers.Count; j++)
         {
            WaveProviders[j].AddSamples(channelbuffers[j].ToArray(), 0, channelbuffers[j].Count());
         }

      }

我們需要為每個通道提供一個WaveProvider（WaveProviders [j]）。