Record live audio from mic input and save simultanously

Question

I was trying to develop a Voice recorder in C#. I have tried many ways, like NAudio, DirectX, Microsoft.Xna.Framework.Audio, etc.

Everything gives the same result. After we stop the recording, the output file mp3/wav get saved.

The mp3/wav file get created at the beginning itself (without and content - 0 bytes)

I am trying to create an application which can save audio live/simultaneously.

    private void StartRecording() {
        this.WaveSource = new WaveInEvent { WaveFormat = new WaveFormat(44100, 1) };

        this.WaveSource.DataAvailable += this.WaveSourceDataAvailable;
        this.WaveSource.RecordingStopped += this.WaveSourceRecordingStopped;

        this.WaveFile = new WaveFileWriter(@"C:\Sample.wav", this.WaveSource.WaveFormat);

        this.WaveSource.StartRecording();
    }

    private void StopRecording() {
        this.WaveSource.StopRecording();
    }

    void WaveSourceDataAvailable(object sender, WaveInEventArgs e) {
        if (this.WaveFile != null) {
            this.WaveFile.Write(e.Buffer, 0, e.BytesRecorded);
            this.WaveFile.Flush();
        }
    }

    void WaveSourceRecordingStopped(object sender, StoppedEventArgs e) {
        if (this.WaveSource != null) {
            this.WaveSource.Dispose();
            this.WaveSource = null;
        }

        if (this.WaveFile != null) {
            this.WaveFile.Dispose();
            this.WaveFile = null;
        }
    }

Answer 1

I have solved the problem with NAudio library itself. Few modification to the existing code.

public class Recorder {

    WaveIn sourceStream;
    WaveFileWriter waveWriter;
    readonly String FilePath;
    readonly String FileName;
    readonly int InputDeviceIndex;

    public Recorder(int inputDeviceIndex, String filePath, String fileName) {
        InitializeComponent();
        this.InputDeviceIndex = inputDeviceIndex;
        this.FileName = fileName;
        this.FilePath = filePath;
    }

    public void StartRecording(object sender, EventArgs e) {
        sourceStream = new WaveIn {
            DeviceNumber = this.InputDeviceIndex,
            WaveFormat =
                new WaveFormat(44100, WaveIn.GetCapabilities(this.InputDeviceIndex).Channels)
        };

        sourceStream.DataAvailable += this.SourceStreamDataAvailable;

        if (!Directory.Exists(FilePath)) {
            Directory.CreateDirectory(FilePath);
        }

        waveWriter = new WaveFileWriter(FilePath + FileName, sourceStream.WaveFormat);
        sourceStream.StartRecording();
    }

    public void SourceStreamDataAvailable(object sender, WaveInEventArgs e) {
        if (waveWriter == null) return;
        waveWriter.Write(e.Buffer, 0, e.BytesRecorded);
        waveWriter.Flush();
    }

    private void RecordEnd(object sender, EventArgs e) {
        if (sourceStream != null) {
            sourceStream.StopRecording();
            sourceStream.Dispose();
            sourceStream = null;
        }
        if (this.waveWriter == null) {
            return;
        }
        this.waveWriter.Dispose();
        this.waveWriter = null;
        recordEndButton.Enabled = false;
        Application.Exit();
        Environment.Exit(0);
    }
}

Answer 2

You can do this with DirectShow. Take a look at Microsoft's documentation and the project's code samples to learn the best way to configure it according to your needs.