1#ifndef KISS_FFT_H
2#define KISS_FFT_H
3
4#include <stdlib.h>
5#include <math.h>
6#include "arch.h"
7
8#ifdef __cplusplus
9extern "C" {
10#endif
11
12/*
13 ATTENTION!
14 If you would like a :
15 -- a utility that will handle the caching of fft objects
16 -- real-only (no imaginary time component ) FFT
17 -- a multi-dimensional FFT
18 -- a command-line utility to perform ffts
19 -- a command-line utility to perform fast-convolution filtering
20
21 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
22  in the tools/ directory.
23*/
24
25#ifdef USE_SIMD
26# include <xmmintrin.h>
27# define kiss_fft_scalar __m128
28#define KISS_FFT_MALLOC(nbytes) memalign(16,nbytes)
29#else
30#define KISS_FFT_MALLOC speex_alloc
31#endif
32
33
34#ifdef FIXED_POINT
35#include "arch.h"
36#  define kiss_fft_scalar spx_int16_t
37#else
38# ifndef kiss_fft_scalar
39/*  default is float */
40#   define kiss_fft_scalar float
41# endif
42#endif
43
44typedef struct {
45    kiss_fft_scalar r;
46    kiss_fft_scalar i;
47}kiss_fft_cpx;
48
49typedef struct kiss_fft_state* kiss_fft_cfg;
50
51/*
52 *  kiss_fft_alloc
53 *
54 *  Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
55 *
56 *  typical usage:      kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
57 *
58 *  The return value from fft_alloc is a cfg buffer used internally
59 *  by the fft routine or NULL.
60 *
61 *  If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
62 *  The returned value should be free()d when done to avoid memory leaks.
63 *
64 *  The state can be placed in a user supplied buffer 'mem':
65 *  If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
66 *      then the function places the cfg in mem and the size used in *lenmem
67 *      and returns mem.
68 *
69 *  If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
70 *      then the function returns NULL and places the minimum cfg
71 *      buffer size in *lenmem.
72 * */
73
74kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
75
76/*
77 * kiss_fft(cfg,in_out_buf)
78 *
79 * Perform an FFT on a complex input buffer.
80 * for a forward FFT,
81 * fin should be  f[0] , f[1] , ... ,f[nfft-1]
82 * fout will be   F[0] , F[1] , ... ,F[nfft-1]
83 * Note that each element is complex and can be accessed like
84    f[k].r and f[k].i
85 * */
86void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
87
88/*
89 A more generic version of the above function. It reads its input from every Nth sample.
90 * */
91void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
92
93/* If kiss_fft_alloc allocated a buffer, it is one contiguous
94   buffer and can be simply free()d when no longer needed*/
95#define kiss_fft_free speex_free
96
97/*
98 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up
99 your compiler output to call this before you exit.
100*/
101void kiss_fft_cleanup(void);
102
103
104#ifdef __cplusplus
105}
106#endif
107
108#endif
109