kiss_fft.h (3364B)
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 // we're using doubles here... 14 #define kiss_fft_scalar double 15 16 /* 17 ATTENTION! 18 If you would like a : 19 -- a utility that will handle the caching of fft objects 20 -- real-only (no imaginary time component ) FFT 21 -- a multi-dimensional FFT 22 -- a command-line utility to perform ffts 23 -- a command-line utility to perform fast-convolution filtering 24 25 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c 26 in the tools/ directory. 27 */ 28 29 #ifdef USE_SIMD 30 # include <xmmintrin.h> 31 # define kiss_fft_scalar __m128 32 #define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16) 33 #define KISS_FFT_FREE _mm_free 34 #else 35 #define KISS_FFT_MALLOC malloc 36 #define KISS_FFT_FREE free 37 #endif 38 39 40 #ifdef FIXED_POINT 41 #include <sys/types.h> 42 # if (FIXED_POINT == 32) 43 # define kiss_fft_scalar int32_t 44 # else 45 # define kiss_fft_scalar int16_t 46 # endif 47 #else 48 # ifndef kiss_fft_scalar 49 /* default is float */ 50 # define kiss_fft_scalar float 51 # endif 52 #endif 53 54 typedef struct { 55 kiss_fft_scalar r; 56 kiss_fft_scalar i; 57 }kiss_fft_cpx; 58 59 typedef struct kiss_fft_state* kiss_fft_cfg; 60 61 /* 62 * kiss_fft_alloc 63 * 64 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. 65 * 66 * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL); 67 * 68 * The return value from fft_alloc is a cfg buffer used internally 69 * by the fft routine or NULL. 70 * 71 * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc. 72 * The returned value should be free()d when done to avoid memory leaks. 73 * 74 * The state can be placed in a user supplied buffer 'mem': 75 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, 76 * then the function places the cfg in mem and the size used in *lenmem 77 * and returns mem. 78 * 79 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), 80 * then the function returns NULL and places the minimum cfg 81 * buffer size in *lenmem. 82 * */ 83 84 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 85 86 /* 87 * kiss_fft(cfg,in_out_buf) 88 * 89 * Perform an FFT on a complex input buffer. 90 * for a forward FFT, 91 * fin should be f[0] , f[1] , ... ,f[nfft-1] 92 * fout will be F[0] , F[1] , ... ,F[nfft-1] 93 * Note that each element is complex and can be accessed like 94 f[k].r and f[k].i 95 * */ 96 void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); 97 98 /* 99 A more generic version of the above function. It reads its input from every Nth sample. 100 * */ 101 void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride); 102 103 /* If kiss_fft_alloc allocated a buffer, it is one contiguous 104 buffer and can be simply free()d when no longer needed*/ 105 #define kiss_fft_free free 106 107 /* 108 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 109 your compiler output to call this before you exit. 110 */ 111 void kiss_fft_cleanup(void); 112 113 114 /* 115 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5) 116 */ 117 int kiss_fft_next_fast_size(int n); 118 119 /* for real ffts, we need an even size */ 120 #define kiss_fftr_next_fast_size_real(n) \ 121 (kiss_fft_next_fast_size( ((n)+1)>>1)<<1) 122 123 #ifdef __cplusplus 124 } 125 #endif 126 127 #endif