如何使用 NAudio 從 UDP 數據包播放音頻 stream？

Question

我從 Voicemeeter 本地接收數據，它使用 VBAN 協議發送字節的 stream。

我正在嘗試使用 NAudio 解碼字節並使用 WaveOutEvent 播放音頻。 我的實現與 NAudioDemo 中的 The NetworkChatDemo 幾乎相同，查看此鏈接以了解有關 NAudio 的更多信息，它是一個很棒的音頻庫，非常感謝 Mark Heath。

我的實現：

private readonly ILogger<AudioController> _logger;
        private NetworkAudioPlayer player;
        private readonly INetworkChatCodec _codec;


        public AudioController(ILogger<AudioController> logger)
        {
            _logger = logger;
            _codec = new ALawChatCodec();
        }

        [HttpGet]
        [Route("start")]
        public IActionResult Start()
        {

            var receiver = new UdpAudioReceiver(6980);
            player = new NetworkAudioPlayer(_codec, receiver);

            return Ok("Hello");
        }

網絡音頻播放器：

private readonly INetworkChatCodec codec;
    private readonly IAudioReceiver receiver;
    private readonly IWavePlayer waveOut;
    private readonly BufferedWaveProvider waveProvider;

    public NetworkAudioPlayer(INetworkChatCodec codec, IAudioReceiver receiver)
    {
        this.codec = codec;
        this.receiver = receiver;
        receiver.OnReceived(OnDataReceived);

        waveOut = new WaveOutEvent();
        waveProvider = new BufferedWaveProvider(codec.RecordFormat);
        waveProvider.BufferDuration = TimeSpan.FromSeconds(300);
        waveOut.Init(waveProvider);
        waveOut.Play();
    }

    void OnDataReceived(byte[] compressed)
    {
        byte[] decoded = codec.Decode(compressed, 0, compressed.Length);
        waveProvider.AddSamples(decoded, 0, decoded.Length);
    }

    public void Dispose()
    {
        receiver?.Dispose();
        waveOut?.Dispose();
    }

我在這個實現中遇到了兩個問題：

• 首先，我無法將 BufferDuration 設置為無限值，因為它是實時的 stream。
• 其次，我什么都聽不到，只有噪音。

如何將 BufferDuration 設置為無限？
如何正確播放音頻？

更新：我能夠通過將 bufferPorivider 的 DiscardOnBufferOverflow 的值設置為 true 來解決第一個問題。

關於噪音問題，我已經從這個問題中找到了解決方案，Mark Heath 提到

另外，您確定接收到的網絡數據包中沒有周圍的元數據嗎？ 如果是這樣，則需要將其剝離，否則會產生噪音。

所以，在將樣本添加到 BufferProvider 時，我將 offset 的值更改為等於 28，這會導致異常：

  void OnDataReceived(byte[] compressed)
        {
            var l = compressed.Length;
            waveProvider.AddSamples(compressed, 28, compressed.Length);
        }

堆棧跟蹤：

    > 
> System.ArgumentException
  HResult=0x80070057
  Message=Source array was not long enough. Check the source index, length, and the array's lower bounds. (Parameter 'sourceArray')
  Source=System.Private.CoreLib
  StackTrace:
   at System.Array.Copy(Array sourceArray, Int32 sourceIndex, Array destinationArray, Int32 destinationIndex, Int32 length, Boolean reliable)
   at System.Array.Copy(Array sourceArray, Int32 sourceIndex, Array destinationArray, Int32 destinationIndex, Int32 length)
   at NAudio.Utils.CircularBuffer.Write(Byte[] data, Int32 offset, Int32 count)
   at NAudio.Wave.BufferedWaveProvider.AddSamples(Byte[] buffer, Int32 offset, Int32 count)
   at POC.AudioStreaming.AudioManagers.NetworkAudioPlayer.OnDataReceived(Byte[] compressed) in C:\dev\POC.AudioStreaming\POC.AudioStreaming\AudioManagers\NetworkAudioPlayer.cs:line 41
   at POC.AudioStreaming.AudioManagers.UdpAudioReceiver.ListenerThread(Object state) in C:\dev\POC.AudioStreaming\POC.AudioStreaming\AudioManagers\UdpAudioReceiver.cs:line 38
   at System.Threading.QueueUserWorkItemCallback.<>c.<.cctor>b__6_0(QueueUserWorkItemCallback quwi)
   at System.Threading.ExecutionContext.RunForThreadPoolUnsafe[TState](ExecutionContext executionContext, Action`1 callback, TState& state)
   at System.Threading.QueueUserWorkItemCallback.Execute()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

如何解決此異常？

Answer 1

我已經通過使用 Skip function 從收到的數據包中修剪前 28 個字節來解決異常：

 void OnDataReceived(byte[] compressed)
    {
        byte[] buffer = compressed.Skip(28).ToArray();
        waveProvider.AddSamples(buffer, 0, buffer.Length);
    }

通過解決異常，我能夠很好地聽到音頻。 另外，我已經回答了我的問題。