annotate fft.h @ 5:5f3c32dc6e17

* Adjust comment syntax to permit Doxygen to generate HTML documentation; add Doxyfile

#ifndef fftH
#define fftH

/**
  \file fft.h - fast Fourier and cosine transforms

  Arguments of the function in this unit roughly follow the following rules:
    Wid   : size of transform
    Order : log2(Wid)
    W     : FFT buffer: twiddle factors, standard size Wid/2
    X     : FFT buffer: data buffer, standard size Wid
    bitinv: FFT buffer: table of bit-inversed integers, standard size Wid
    Window: window function, standard size Wid
    spec  : complex spectrogram
    Amp   : amplitude spectrogram
    Arg   : phase spectrogram
    prefix h- : half-size
    prefix q- : quarter-size
*/


#include <math.h>
#include "xcomplex.h"
#include "align8.h"

//---------------------------------------------------------------------------
/**
  macro AllocateFFTBuffer: allocates FFT buffers X and W of given length with an extra LDATA buffer the
  right size for hosting such arrays as the standard-size window function or output amplitude spectrum.

  This macro allocates buffer with 64-bit alignment, which must be freed with free8() or FreeFFTBuffer
  macro.
*/
#define AllocateFFTBuffer(_WID, _LDATA, _W, _X) \
  double *_LDATA=(double*)malloc8(sizeof(double)*_WID*4); \
  cdouble *_X=(cdouble*)&_LDATA[_WID]; \
  cdouble *_W=(cdouble*)&_X[_WID]; \
  SetTwiddleFactors(_WID, _W);
#define FreeFFTBuffer(_LDATA) free8(_LDATA);

//--compelx FFT and IFFT-----------------------------------------------------
void CFFTCbii(int Order, cdouble* W, cdouble* X); //complex FFT subroutine after bit-inversed ordering
void CFFTC(int Order, cdouble* W, cdouble* X, int* bitinv=0); //complex FFT, compact in-place
void CFFTC(cdouble* Input, double* Amp, double *Arg, int Order, cdouble* W, cdouble* X, int* bitinv=0); //complex FFT
void CFFTCW(double* Window, int Order, cdouble* W, cdouble* X, int* bitinv=0);  //complex FFT with window, compact in-place
void CFFTCW(cdouble* Input, double* Window, double *Amp, double *Arg, int Order, cdouble* W, cdouble* X, int* bitinv=0);  //complex FFT with window
void CIFFTC(int Order, cdouble* W, cdouble* X, int* bitinv=0);  //complex IFFT, compact in-place
void CIFFTC(cdouble* Input, int Order, cdouble* W, cdouble* X, int* bitinv=0);  //complex IFFT

//--real FFT and IFFT--------------------------------------------------------
void RFFTC_ual(double* Input, double* Amp, double* Arg, int Order, cdouble* W, cdouble* X, int* hbitinv=0); //real-to-complex FFT
void RFFTC_ual_old(double* Input, double *Amp, double *Arg, int Order, cdouble* W, double* XR, double* XI, int* bitinv=0);  //depreciated
void RFFTCW(double* Input, double* Window, double *Amp, double *Arg, int Order, cdouble* W, cdouble* X, int* hbitinv=0);  //real-to-complex FFT with window, double-type input
void RFFTCW(__int16* Input, double* Window, double *Amp, double *Arg, int Order, cdouble* W, cdouble* X, int* hbitinv=0); //real-to-complex FFT with window, __int16 input
void CIFFTR(cdouble* Input, int Order, cdouble* W, double* X, int* hbitinv=0);  //complex-to-real IFFT

/*
  macro RFFTC: was defined as RFFTC_ual (literally "unaligned RFFTC") enveloped by ALIGN8(). However, as
  ALIGN8() is currently disabled for lack of compiler support, RFFTC is equivalent to RFFTC_ual.
*/
#define RFFTC(Input, Amp, Arg, Order, W, X, hbitinv) RFFTC_ual(Input, Amp, Arg, Order, W, X, hbitinv);

//--MFT----------------------------------------------------------------------
void CMFTC(double* xR, double* xI, int Order, cdouble** X, cdouble* W); //complex fast multiresolution FT

//--DCT and IDCT-------------------------------------------------------------
void RDCT1(double* Input, double* Output, int Order, cdouble* qW, cdouble* qX, int* qbitinv=0);   //DCT1
void RDCT4(double* Input, double* Output, int Order, cdouble* hW, cdouble* hX, int* hbitinv=0);   //DCT4
void RIDCT1(double* Input, double* Output, int Order, cdouble* qW, cdouble* qX, int* qbitinv=0);  //IDCT1
void RIDCT4(double* Input, double* Output, int Order, cdouble* hW, cdouble* hX, int* hbitinv=0);  //IDCT4

//--LCT----------------------------------------------------------------------
void RLCT(double** spec, double* data, int Count, int Order, int wid, double* g); //local cosine transform
void RILCT(double* data, double** spec, int Fr, int Order, int wid, double* g);   //inverse local cosine transform

//--tools--------------------------------------------------------------------
double Atan2(double, double);
int* CreateBitInvTable(int Order);  //creates table of bit-inversed integers
void SetTwiddleFactors(int N, cdouble* w);  //set twiddle factors


#endif