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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
9 extern "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 
44 typedef struct {
45     kiss_fft_scalar r;
46     kiss_fft_scalar i;
47 }kiss_fft_cpx;
48 
49 typedef 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 
74 kiss_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  * */
86 void 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  * */
91 void 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 */
101 void kiss_fft_cleanup(void);
102 
103 
104 #ifdef __cplusplus
105 }
106 #endif
107 
108 #endif
109