//filterCutoff is 0..1 (-6 dB point)
/// <summary>Initializes a new instance of the <see cref="IppResampler" /> class.</summary>
/// <param name="inRate">The input sampling rate.</param>
/// <param name="outRate">The output sampling rate.</param>
/// <param name="requestedFilterOrder">The requested filter order.</param>
/// <param name="filterCutoff">The 6-dB cutoff frequency of the anti-aliasing filter
/// as a fraction of the Nyquist frequency. Must be in the range of 0...1.</param>
/// <param name="kaiserAlpha">The alpha parameter of the Kaiser filter.</param>
public IppResampler(int inRate, int outRate, int requestedFilterOrder, float filterCutoff, float kaiserAlpha)
{
this.inRate = inRate;
this.outRate = outRate;
//allocate memory for the resampler structure
int specSize, filterOrder, filterHeight;
IppStatus rc;
rc = Ipp.ippsResamplePolyphaseFixedGetSize_32f(inRate, outRate, requestedFilterOrder, &specSize,
&filterOrder, &filterHeight, IppHintAlgorithm.ippAlgHintFast);
IppException.Check(rc);
//{!} docs suggest to use ippsMalloc_8u(specSize), but that results in memory corruption
pSpec = (IppsResamplingPolyphaseFixed_32f *)Ipp.ippsMalloc_8u(specSize * filterHeight);
//initialize IPP resampler
rc = Ipp.ippsResamplePolyphaseFixedInit_32f(inRate, outRate, filterOrder, filterCutoff,
kaiserAlpha, pSpec, IppHintAlgorithm.ippAlgHintFast);
IppException.Check(rc);
//set up input buffer
inData = new float[filterOrder];
readIndex = readIndex0 = filterOrder / 2;
writeIndex = writeIndex0 = filterOrder;
}
/// <summary>Initializes a new instance of the <see cref="ComplexFft" /> class.</summary>
/// <param name="size">The size of the FFT transform.</param>
public ComplexFft(int size) : base(size)
{
//allocate input buffer
TimeData = new Complex32[size];
FreqData = new Complex32[size];
//calculate FFT buffer sizes
int specBufSize, initBufSize, workBufSize;
IppStatus rc = sp.ippsFFTGetSize_C_32fc(order, IPP_FFT_NODIV_BY_ANY,
IppHintAlgorithm.ippAlgHintNone, &specBufSize, &initBufSize, &workBufSize);
IppException.Check(rc);
//allocate FFT buffers
Dispose();
specBuffer = Ipp.ippsMalloc_8u(specBufSize);
byte[] initBuf = new byte[initBufSize];
workBuf = new byte[workBufSize];
//initialize FFT
fixed(byte *pInitBuf = initBuf)
fixed(IppsFFTSpec_C_32fc **ppFftSpec = &pFftSpec)
{
rc = sp.ippsFFTInit_C_32fc(ppFftSpec, order, IPP_FFT_NODIV_BY_ANY,
IppHintAlgorithm.ippAlgHintNone, specBuffer, pInitBuf);
}
IppException.Check(rc);
}
/// <summary>Initializes a new instance of the <see cref="RealFft" /> class.</summary>
/// <param name="size">The size of the FFT transform.</param>
public RealFft(int size) : base(size)
{
TimeData = new float[size];
FreqData = new Complex32[size / 2 + 1];
int specBufSize, initBufSize, workBufSize;
IppStatus rc = sp.ippsFFTGetSize_R_32f(order, IPP_FFT_NODIV_BY_ANY,
IppHintAlgorithm.ippAlgHintNone, &specBufSize, &initBufSize, &workBufSize);
IppException.Check(rc);
specBuffer = Ipp.ippsMalloc_8u(specBufSize);
byte[] initBuf = new byte[initBufSize];
workBuf = new byte[workBufSize];
fixed(byte *pInitBuf = initBuf)
fixed(IppsFFTSpec_R_32f **ppFftSpec = &pFftSpec)
{
rc = sp.ippsFFTInit_R_32f(ppFftSpec, order, IPP_FFT_NODIV_BY_ANY,
IppHintAlgorithm.ippAlgHintNone, specBuffer, pInitBuf);
}
IppException.Check(rc);
}
