public BufferedFFT(int bufferSize, int fftSize, ILoudnessWeighting weighting = null)
{
this.bufferSize = bufferSize;
this.fftSize = fftSize;
this.LoudnessWeighting = weighting != null ? weighting : new NullWeighting(fftSize / 4);
ringBuffer = new RingBuffer <float>(bufferSize);
fft = new FFT(fftSize);
}
public void CopyTo(float[] dest, int offset, int count, int stride, ILoudnessWeighting weighting)
{
int max = count;
if (max > size / 2)
{
max = size / 2;
}
if (weighting.Size < max)
{
throw new ArgumentOutOfRangeException("Weighting not large enough");
}
int desti = offset;
for (int i = 0; i < max; i++)
{
float freq = (float)i / (float)((size / 2) - 1);
dest[desti] = (float)(Math.Sqrt(fftTempComplex[i].X * fftTempComplex[i].X + fftTempComplex[i].Y * fftTempComplex[i].Y) * weighting[freq]);
desti += stride;
}
}
/// <summary>
/// Creates a buffered FFT sized to generate the given output.
///
/// FFT is made twice the size of the output buffer, because we discard all frequencies above the Nyquist rate.
/// The ring buffer is made twice the size of the FFT (so 4 times the size of the output).
///
/// </summary>
/// <param name="outputSize"></param>
/// <param name="weighting"></param>
public BufferedFFT(int outputSize, ILoudnessWeighting weighting = null) : this(outputSize * 4, outputSize * 2, weighting)
{
}