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view libs/kissfft/kiss_fft.h @ 0:b2f14e535253
initial commit
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sat, 01 Feb 2014 19:58:19 +0200 |
| parents | |
| children |
line source
1 #ifndef KISS_FFT_H
2 #define KISS_FFT_H
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <math.h>
7 #include <string.h>
9 #ifdef __cplusplus
10 extern "C" {
11 #endif
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
22 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
23 in the tools/ directory.
24 */
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
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
51 typedef struct {
52 kiss_fft_scalar r;
53 kiss_fft_scalar i;
54 }kiss_fft_cpx;
56 typedef struct kiss_fft_state* kiss_fft_cfg;
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 * */
81 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
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 * */
93 void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
95 /*
96 A more generic version of the above function. It reads its input from every Nth sample.
97 * */
98 void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
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
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 */
108 void kiss_fft_cleanup(void);
111 /*
112 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
113 */
114 int kiss_fft_next_fast_size(int n);
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)
120 #ifdef __cplusplus
121 }
122 #endif
124 #endif