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 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) _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 35 36 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 50 51 typedef struct { 52 kiss_fft_scalar r; 53 kiss_fft_scalar i; 54 }kiss_fft_cpx; 55 56 typedef struct kiss_fft_state* kiss_fft_cfg; 57 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 * */ 80 81 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 82 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); 94 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); 99 100 /* 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 103 104 /* 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); 109 110 111 /* 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); 115 116 /* 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) 119 120 #ifdef __cplusplus 121 } 122 #endif 123 124 #endif 125
