1#ifndef KISS_FFT_H
  2#define KISS_FFT_H
  3
  4#include <stdlib.h>
  5#include <stdio.h>
  6#include <math.h>
  7#include <string.h>
  8
  9#ifdef __cplusplus
 10extern "C" {
 11#endif
 12
 13/*
 14 ATTENTION!
 15 If you would like a :
 16 -- a utility that will handle the caching of fft objects
 17 -- real-only (no imaginary time component ) FFT
 18 -- a multi-dimensional FFT
 19 -- a command-line utility to perform ffts
 20 -- a command-line utility to perform fast-convolution filtering
 21
 22 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
 23  in the tools/ directory.
 24*/
 25
 26#ifdef USE_SIMD
 27# include <xmmintrin.h>
 28# define kiss_fft_scalar __m128
 29#define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
 30#define KISS_FFT_FREE _mm_free
 31#else	
 32#define KISS_FFT_MALLOC malloc
 33#define KISS_FFT_FREE free
 34#endif	
 35
 36
 37#ifdef FIXED_POINT
 38#include <sys/types.h>	
 39# if (FIXED_POINT == 32)
 40#  define kiss_fft_scalar int32_t
 41# else	
 42#  define kiss_fft_scalar int16_t
 43# endif
 44#else
 45# ifndef kiss_fft_scalar
 46/*  default is float */
 47#   define kiss_fft_scalar float
 48# endif
 49#endif
 50
 51typedef struct {
 52    kiss_fft_scalar r;
 53    kiss_fft_scalar i;
 54}kiss_fft_cpx;
 55
 56typedef struct kiss_fft_state* kiss_fft_cfg;
 57
 58/* 
 59 *  kiss_fft_alloc
 60 *  
 61 *  Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
 62 *
 63 *  typical usage:      kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
 64 *
 65 *  The return value from fft_alloc is a cfg buffer used internally
 66 *  by the fft routine or NULL.
 67 *
 68 *  If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
 69 *  The returned value should be free()d when done to avoid memory leaks.
 70 *  
 71 *  The state can be placed in a user supplied buffer 'mem':
 72 *  If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
 73 *      then the function places the cfg in mem and the size used in *lenmem
 74 *      and returns mem.
 75 *  
 76 *  If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
 77 *      then the function returns NULL and places the minimum cfg 
 78 *      buffer size in *lenmem.
 79 * */
 80
 81kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 
 82
 83/*
 84 * kiss_fft(cfg,in_out_buf)
 85 *
 86 * Perform an FFT on a complex input buffer.
 87 * for a forward FFT,
 88 * fin should be  f[0] , f[1] , ... ,f[nfft-1]
 89 * fout will be   F[0] , F[1] , ... ,F[nfft-1]
 90 * Note that each element is complex and can be accessed like
 91    f[k].r and f[k].i
 92 * */
 93void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
 94
 95/*
 96 A more generic version of the above function. It reads its input from every Nth sample.
 97 * */
 98void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
 99
100/* If kiss_fft_alloc allocated a buffer, it is one contiguous 
101   buffer and can be simply free()d when no longer needed*/
102#define kiss_fft_free free
103
104/*
105 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 
106 your compiler output to call this before you exit.
107*/
108void kiss_fft_cleanup(void);
109	
110
111/*
112 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
113 */
114int kiss_fft_next_fast_size(int n);
115
116/* for real ffts, we need an even size */
117#define kiss_fftr_next_fast_size_real(n) \
118        (kiss_fft_next_fast_size( ((n)+1)>>1)<<1)
119
120#ifdef __cplusplus
121} 
122#endif
123
124#endif