public WaveCapture(IWaveIn capture, int fftSize, double moveSpeed, DSP.Window window = null)
{
this.capture = capture;
capture.DataAvailable += (sender, e) => {
observer?.Write(MemoryMarshal.Cast <byte, float>(e.Buffer.AsSpan(0, e.BytesRecorded)));
};
Reset(fftSize, moveSpeed, window);
}
public SharedStreamObserver(IWaveIn capture, int fftSize, double moveSpeed, DSP.Window fftWindow)
{
this.capture = capture;
this.fftWindow = fftWindow;
fft = FFT.CreateFFT(fftSize);
leftFFTData = new Complex[fft.FFTComplexCount];
rightFFTData = new Complex[fft.FFTComplexCount];
streamObserver = new StreamObserver <float>(fftSize, (int)(fftSize / moveSpeed), 2, true);
streamObserver.Completed += StreamObserver_Completed;
capture.DataAvailable += Capture_DataAvailable;
}
public void Reset(int fftSize, double moveSpeed, DSP.Window window)
{
lock (@lock) {
this.fftSize = fftSize;
fftComplexCount = fftSize / 2 + 1;
this.moveSpeed = moveSpeed;
fftWindow = window;
if (fft != null)
{
fft = FFT.CreateFFT(fftSize);
CreateObserver();
}
}
}
/// <summary>
/// FFT结果取模
/// </summary>
/// <param name="fftSize">fft大小</param>
/// <param name="src">输入缓冲区</param>
/// <param name="dst">输出缓冲区</param>
/// <param name="sqrt">true则进行sqrt运算</param>
public static void Abs(int fftSize, ReadOnlySpan <Complex> src, Span <double> dst, bool sqrt = true, DSP.Window window = null)
{
src.Handle(dst, GetComplexCount(fftSize), (@in, @out, length) => {
double scale0 = window != null ? window.Scale : 1.0 / fftSize;
double scale = window != null ? 2 * window.Scale : 2.0 / fftSize;
if (sqrt)
{
@out[0] = @in[0].Magnitude * scale0;
for (int i = 1; i < length; i++)
{
@out[i] = @in[i].Magnitude * scale;
}
}
else
{
@out[0] = (@in[0].Real * @in[0].Real + @in[0].Imaginary * @in[0].Imaginary) * scale0;
for (int i = 1; i < length; i++)
{
@out[i] = (@in[i].Real * @in[i].Real + @in[i].Imaginary * @in[i].Imaginary) * scale;
}
}
});
}
