/// <summary>
/// Changes <paramref name="kernel"/> coefficients online.
/// </summary>
public void ChangeKernel(double[] kernel)
{
if (kernel.Length != _kernel.Length)
{
return;
}
Array.Clear(_kernelSpectrumRe, 0, _fftSize);
kernel.FastCopyTo(_kernel, kernel.Length);
kernel.FastCopyTo(_kernelSpectrumRe, kernel.Length);
_fft.Direct(_kernelSpectrumRe, _kernelSpectrumRe, _kernelSpectrumIm);
}
public void Fft64Array()
{
var input = new double[FrameSize];
var re = new double[FrameSize];
var im = new double[FrameSize];
for (var i = 0; i < N - FrameSize; i += HopSize)
{
_samples64.FastCopyTo(input, FrameSize, i);
_fft64.Direct(input, re, im);
}
}
/// <summary>
/// Process one frame (block)
/// </summary>
public void ProcessFrame()
{
var M = _kernel.Length;
var halfSize = _fftSize / 2;
Array.Clear(_blockRe, HopSize, M - 1);
_fft.Direct(_blockRe, _blockRe, _blockIm);
for (var j = 0; j <= halfSize; j++)
{
_convRe[j] = (_blockRe[j] * _kernelSpectrumRe[j] - _blockIm[j] * _kernelSpectrumIm[j]) / _fftSize;
_convIm[j] = (_blockRe[j] * _kernelSpectrumIm[j] + _blockIm[j] * _kernelSpectrumRe[j]) / _fftSize;
}
_fft.Inverse(_convRe, _convIm, _convRe);
for (var j = 0; j < M - 1; j++)
{
_convRe[j] += _lastSaved[j];
}
_convRe.FastCopyTo(_lastSaved, M - 1, HopSize);
_outputBufferOffset = 0;
_bufferOffset = 0;
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="kernel"></param>
/// <param name="fftSize"></param>
public OlaBlockConvolver64(IEnumerable <double> kernel, int fftSize)
{
_kernel = kernel.ToArray();
_fftSize = MathUtils.NextPowerOfTwo(fftSize);
Guard.AgainstExceedance(_kernel.Length, _fftSize, "Kernel length", "the size of FFT");
_fft = new RealFft64(_fftSize);
_kernelSpectrumRe = _kernel.PadZeros(_fftSize);
_kernelSpectrumIm = new double[_fftSize];
_convRe = new double[_fftSize];
_convIm = new double[_fftSize];
_blockRe = new double[_fftSize];
_blockIm = new double[_fftSize];
_lastSaved = new double[_kernel.Length - 1];
_fft.Direct(_kernelSpectrumRe, _kernelSpectrumRe, _kernelSpectrumIm);
Reset();
}