1 #ifndef KISS_FFT_F64_H 2 #define KISS_FFT_F64_H 3 4 #include <stdlib.h> 5 #include <stdio.h> 6 #include <math.h> 7 #include <string.h> 8 #include <glib.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 #define KISS_FFT_F64_MALLOC g_malloc 28 #define kiss_fft_f64_scalar double 29 30 typedef struct { 31 kiss_fft_f64_scalar r; 32 kiss_fft_f64_scalar i; 33 }kiss_fft_f64_cpx; 34 35 typedef struct kiss_fft_f64_state* kiss_fft_f64_cfg; 36 37 /* 38 * kiss_fft_f64_alloc 39 * 40 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. 41 * 42 * typical usage: kiss_fft_f64_cfg mycfg=kiss_fft_f64_alloc(1024,0,NULL,NULL); 43 * 44 * The return value from fft_alloc is a cfg buffer used internally 45 * by the fft routine or NULL. 46 * 47 * If lenmem is NULL, then kiss_fft_f64_alloc will allocate a cfg buffer using malloc. 48 * The returned value should be free()d when done to avoid memory leaks. 49 * 50 * The state can be placed in a user supplied buffer 'mem': 51 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, 52 * then the function places the cfg in mem and the size used in *lenmem 53 * and returns mem. 54 * 55 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), 56 * then the function returns NULL and places the minimum cfg 57 * buffer size in *lenmem. 58 * */ 59 60 kiss_fft_f64_cfg kiss_fft_f64_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 61 62 /* 63 * kiss_fft(cfg,in_out_buf) 64 * 65 * Perform an FFT on a complex input buffer. 66 * for a forward FFT, 67 * fin should be f[0] , f[1] , ... ,f[nfft-1] 68 * fout will be F[0] , F[1] , ... ,F[nfft-1] 69 * Note that each element is complex and can be accessed like 70 f[k].r and f[k].i 71 * */ 72 void kiss_fft_f64(kiss_fft_f64_cfg cfg,const kiss_fft_f64_cpx *fin,kiss_fft_f64_cpx *fout); 73 74 /* 75 A more generic version of the above function. It reads its input from every Nth sample. 76 * */ 77 void kiss_fft_f64_stride(kiss_fft_f64_cfg cfg,const kiss_fft_f64_cpx *fin,kiss_fft_f64_cpx *fout,int fin_stride); 78 79 /* If kiss_fft_f64_alloc allocated a buffer, it is one contiguous 80 buffer and can be simply free()d when no longer needed*/ 81 #define kiss_fft_f64_free g_free 82 83 /* 84 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 85 your compiler output to call this before you exit. 86 */ 87 void kiss_fft_f64_cleanup(void); 88 89 90 /* 91 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5) 92 */ 93 int kiss_fft_f64_next_fast_size(int n); 94 95 /* for real ffts, we need an even size */ 96 #define kiss_fftr_next_fast_size_real(n) \ 97 (kiss_fft_next_fast_size( ((n)+1)>>1)<<1) 98 99 #ifdef __cplusplus 100 } 101 #endif 102 103 #endif 104