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