Audio and video recording from screen (output audio. Not microphone input)

AudioAndVideoRecording.cs

//1) Add projects: Captura.Base, Captura.Bass, Captura.SharpAvi, Screna from this repository:
https://github.com/MathewSachin v8.0.0

//2) Copy bass.dll & bassmix.dll from x64 folder:
//http://www.un4seen.com/files/bassmix24.zip
//http://www.un4seen.com/files/bass24.zip


recordTask = new Task((cancelationToken) =>
{
    var fps = 30;
    var sharpAVICodec = new SharpAviItem(AviCodec.MotionJpeg, "Motion JPEG encoder using WPF's JPG encoder");
    using (var imageProvider = new ImageProvider(height, width, dpiKoeff, rect.Left, rect.Top))
    using (var audioSource = new BassAudioSource(new Captura.AudioSettings()
    {
        Enabled = true,
        PlaybackRecordingRealTime = false,
        Quality = 100,
    }))
    using (var audioProvider = audioSource.GetMixedAudioProvider())
    using (var videoWriter = sharpAVICodec.GetVideoFileWriter(new Captura.Models.VideoWriterArgs()
    {
        FileName = _capturedVideoPath,
        AudioProvider = audioProvider,
        AudioQuality = 70,
        FrameRate = fps,
        ImageProvider = imageProvider,
        VideoQuality = 70
    }))
    using (var recorder = new Recorder(videoWriter, imageProvider, fps, audioProvider))
    {
        //error:
        //foreach(var rs in audioSource.AvailableRecordingSources)
        //    rs.Active = true;

        foreach (var ls in audioSource.AvailableLoopbackSources)
            ls.Active = true;

        recorder.Start();

        while (!recordTaskCancel.IsCancellationRequested)
            Task.Yield();

        recorder.Stop();
    }

    }
}, recordTaskCancel.Token);
recordTask.Start();



internal class ImageProvider : IImageProvider
{
    public ImageProvider(int height, int width, double dpiKoeff, int left, int top)
    {
        Height = height;
        Width = width;
        DPIKoeff = dpiKoeff;
        Left = left;
        Top = top;
    }

    public int Height { get; }
    public int Width { get; }
    public int Left { get; }
    public int Top { get; }
    public double DPIKoeff { get; }

    public IBitmapFrame Capture()
    {
        return new OneTimeFrame(GetScreenshot(Left, Top, Width, Height));
    }

    public void Dispose()
    {
    }

    private Bitmap GetScreenshot(int left, int top, int screenWidth, int screenHeight)
    {
        var bitmap = new Bitmap(screenWidth, screenHeight);
        using (var graphics = Graphics.FromImage(bitmap))
        {
            graphics.CopyFromScreen(left, top, 0, 0, new System.Drawing.Size(screenWidth, screenHeight));
            var mousePos = WinProcess.GetMousePosition();
            var mouseDpiAdditionalOffset = -(200.0 - (200.0 * DPIKoeff));
            graphics.FillEllipse(
                new SolidBrush(Color.Red),
                (float)(mousePos.X - (left / DPIKoeff) + mouseDpiAdditionalOffset),
                (float)(mousePos.Y - (top / DPIKoeff) + mouseDpiAdditionalOffset),
                10,
                10);
            graphics.Flush();
        }
        return bitmap;
    }
}





        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        internal static extern bool GetCursorPos(ref Win32Point pt);

        [StructLayout(LayoutKind.Sequential)]
        internal struct Win32Point
        {
            public Int32 X;
            public Int32 Y;
        };
        public static Point GetMousePosition()
        {
            var w32Mouse = new Win32Point();
            GetCursorPos(ref w32Mouse);

            return new Point(w32Mouse.X, w32Mouse.Y);
        }