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 <string.h> 8 /*#include <malloc.h>*/ 9 10 #ifdef __cplusplus 11 extern "C" { 12 #endif 13 14 /* 15 ATTENTION! 16 If you would like a : 17 -- a utility that will handle the caching of fft objects 18 -- real-only (no imaginary time component ) FFT 19 -- a multi-dimensional FFT 20 -- a command-line utility to perform ffts 21 -- a command-line utility to perform fast-convolution filtering 22 23 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c 24 in the tools/ directory. 25 */ 26 27 #ifdef USE_SIMD 28 # include <xmmintrin.h> 29 # define kiss_fft_scalar __m128 30 #define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16) 31 #define KISS_FFT_FREE _mm_free 32 #else 33 #define KISS_FFT_MALLOC malloc 34 #define KISS_FFT_FREE free 35 #endif 36 37 38 #ifdef FIXED_POINT 39 #include <sys/types.h> 40 # if (FIXED_POINT == 32) 41 # define kiss_fft_scalar int32_t 42 # else 43 # define kiss_fft_scalar int16_t 44 # endif 45 #else 46 # ifndef kiss_fft_scalar 47 /* default is float */ 48 # define kiss_fft_scalar float 49 # endif 50 #endif 51 52 typedef struct { 53 kiss_fft_scalar r; 54 kiss_fft_scalar i; 55 }kiss_fft_cpx; 56 57 typedef struct kiss_fft_state* kiss_fft_cfg; 58 59 /* 60 * kiss_fft_alloc 61 * 62 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. 63 * 64 * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL); 65 * 66 * The return value from fft_alloc is a cfg buffer used internally 67 * by the fft routine or NULL. 68 * 69 * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc. 70 * The returned value should be free()d when done to avoid memory leaks. 71 * 72 * The state can be placed in a user supplied buffer 'mem': 73 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, 74 * then the function places the cfg in mem and the size used in *lenmem 75 * and returns mem. 76 * 77 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), 78 * then the function returns NULL and places the minimum cfg 79 * buffer size in *lenmem. 80 * */ 81 82 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 83 84 /* 85 * kiss_fft(cfg,in_out_buf) 86 * 87 * Perform an FFT on a complex input buffer. 88 * for a forward FFT, 89 * fin should be f[0] , f[1] , ... ,f[nfft-1] 90 * fout will be F[0] , F[1] , ... ,F[nfft-1] 91 * Note that each element is complex and can be accessed like 92 f[k].r and f[k].i 93 * */ 94 void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); 95 96 /* 97 A more generic version of the above function. It reads its input from every Nth sample. 98 * */ 99 void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride); 100 101 /* If kiss_fft_alloc allocated a buffer, it is one contiguous 102 buffer and can be simply free()d when no longer needed*/ 103 #define kiss_fft_free free 104 105 /* 106 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 107 your compiler output to call this before you exit. 108 */ 109 void kiss_fft_cleanup(void); 110 111 112 /* 113 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5) 114 */ 115 int kiss_fft_next_fast_size(int n); 116 117 /* for real ffts, we need an even size */ 118 #define kiss_fftr_next_fast_size_real(n) \ 119 (kiss_fft_next_fast_size( ((n)+1)>>1)<<1) 120 121 #ifdef __cplusplus 122 } 123 #endif 124 125 #endif 126