unwanted silence parts in NAudio recording

问题

I try to write an application that records the sound from the microphone and send it directly to the speakers. For testing I use a headset to avoid an acoustic feedback. I found this tutorial https://markheath.net/post/how-to-record-and-play-audio-at-same . Since I had a problem in my final application with this, I created a small test app to make sure that the cause of my problem isn't some side effect. I create a small test program with 2 buttons (start&stop) to test it. But for some reason the recorded sound in my bigger finale app and in this app has periodic silence parts which I can't find why.

This is my code:

public partial class MainWindow : Window
{
    private AudioLive MyLive;
    public MainWindow()
    {
        InitializeComponent();

        MyLive = new AudioLive();
        MyLive.Init();


    }

    private void ButtonStart(object sender, RoutedEventArgs e)
    {
        MyLive.StartLive();
    }

    private void ButtonEnd(object sender, RoutedEventArgs e)
    {
        MyLive.EndLive();
    }
}

class AudioLive
{

    private WaveIn m_Recorder;
    private BufferedWaveProvider m_BufferedWaveProvider;
    private SavingWaveProvider m_SavingWaveProvider;
    private WaveOut m_Player;


    public void Dispose()
    {
        Dispose(true);

    }



    protected virtual void Dispose(bool disposing)
    {
        if (m_Recorder != null)
        {
            m_Recorder.Dispose();
        }


        m_Recorder = null;

        if (m_SavingWaveProvider != null)
        {
            m_SavingWaveProvider.Dispose();
        }


        m_SavingWaveProvider = null;

    }

    private void RecorderOnDataAvailable(object sender, WaveInEventArgs waveInEventArgs)
    {            
        m_BufferedWaveProvider.AddSamples(waveInEventArgs.Buffer, 0, waveInEventArgs.BytesRecorded);            
    }



    public bool Init()
    {
        m_Recorder = new WaveIn();
        m_Recorder.WaveFormat = new WaveFormat(44100, 2);

        m_Recorder.DataAvailable += RecorderOnDataAvailable;

        // set up our signal chain
        m_BufferedWaveProvider = new BufferedWaveProvider(m_Recorder.WaveFormat);

        return true;
    }




    public void StartLive()
    {

        m_SavingWaveProvider = new SavingWaveProvider(m_BufferedWaveProvider, "live.wav");

        // set up playback
        m_Player = new WaveOut();
        m_Player.Init(m_SavingWaveProvider);

        // begin playback & record
        m_Player.Play();

        m_Recorder.StartRecording();

    }



    public void EndLive()
    {

        // stop recording
        m_Recorder.StopRecording();
        // stop playback
        m_Player.Stop();
        m_Player.Dispose();

        // finalise the WAV file
        m_SavingWaveProvider.Dispose();

    }


}

My test application doesn't containing anything else than these 2 buttons. Has anybody an idea why I get these periodical silence parts during recording?

回答1:

It's because BufferedWaveProvider produces silence if it doesn't have any audio buffered, which can happen when live streaming audio. It would be better for you simply to write received audio into a WaveFileWriter as well as putting it into BufferedWaveProvider in RecorderOnDataAvailable instead of using SavingWaveProvider.

来源：https://stackoverflow.com/questions/53847245/unwanted-silence-parts-in-naudio-recording

标签

audio-recording

naudio