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 <memory.h>
8 
9 #ifdef __cplusplus
10 extern "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) memalign(16,nbytes)
30 #else
31 #define KISS_FFT_MALLOC malloc
32 #endif
33 
34 
35 #ifdef FIXED_POINT
36 #include <sys/types.h>
37 #  define kiss_fft_scalar int16_t
38 #else
39 # ifndef kiss_fft_scalar
40 /*  default is float */
41 #   define kiss_fft_scalar float
42 # endif
43 #endif
44 
45 typedef struct {
46     kiss_fft_scalar r;
47     kiss_fft_scalar i;
48 }kiss_fft_cpx;
49 
50 typedef struct kiss_fft_state* kiss_fft_cfg;
51 
52 /*
53  *  kiss_fft_alloc
54  *
55  *  Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
56  *
57  *  typical usage:      kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
58  *
59  *  The return value from fft_alloc is a cfg buffer used internally
60  *  by the fft routine or NULL.
61  *
62  *  If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
63  *  The returned value should be free()d when done to avoid memory leaks.
64  *
65  *  The state can be placed in a user supplied buffer 'mem':
66  *  If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
67  *      then the function places the cfg in mem and the size used in *lenmem
68  *      and returns mem.
69  *
70  *  If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
71  *      then the function returns NULL and places the minimum cfg
72  *      buffer size in *lenmem.
73  * */
74 
75 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
76 
77 /*
78  * kiss_fft(cfg,in_out_buf)
79  *
80  * Perform an FFT on a complex input buffer.
81  * for a forward FFT,
82  * fin should be  f[0] , f[1] , ... ,f[nfft-1]
83  * fout will be   F[0] , F[1] , ... ,F[nfft-1]
84  * Note that each element is complex and can be accessed like
85     f[k].r and f[k].i
86  * */
87 void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
88 
89 /*
90  A more generic version of the above function. It reads its input from every Nth sample.
91  * */
92 void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
93 
94 /* If kiss_fft_alloc allocated a buffer, it is one contiguous
95    buffer and can be simply free()d when no longer needed*/
96 #define kiss_fft_free free
97 
98 /*
99  Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up
100  your compiler output to call this before you exit.
101 */
102 void kiss_fft_cleanup(void);
103 
104 
105 #ifdef __cplusplus
106 }
107 #endif
108 
109 #endif
110