1 #ifndef KISS_FFT_H 2 #define KISS_FFT_H 3 4 #include <stdlib.h> 5 #include <math.h> 6 #include "arch.h" 7 8 #ifdef __cplusplus 9 extern "C" { 10 #endif 11 12 /* 13 ATTENTION! 14 If you would like a : 15 -- a utility that will handle the caching of fft objects 16 -- real-only (no imaginary time component ) FFT 17 -- a multi-dimensional FFT 18 -- a command-line utility to perform ffts 19 -- a command-line utility to perform fast-convolution filtering 20 21 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c 22 in the tools/ directory. 23 */ 24 25 #ifdef USE_SIMD 26 # include <xmmintrin.h> 27 # define kiss_fft_scalar __m128 28 #define KISS_FFT_MALLOC(nbytes) memalign(16,nbytes) 29 #else 30 #define KISS_FFT_MALLOC speex_alloc 31 #endif 32 33 34 #ifdef FIXED_POINT 35 #include "arch.h" 36 # define kiss_fft_scalar spx_int16_t 37 #else 38 # ifndef kiss_fft_scalar 39 /* default is float */ 40 # define kiss_fft_scalar float 41 # endif 42 #endif 43 44 typedef struct { 45 kiss_fft_scalar r; 46 kiss_fft_scalar i; 47 }kiss_fft_cpx; 48 49 typedef struct kiss_fft_state* kiss_fft_cfg; 50 51 /* 52 * kiss_fft_alloc 53 * 54 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. 55 * 56 * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL); 57 * 58 * The return value from fft_alloc is a cfg buffer used internally 59 * by the fft routine or NULL. 60 * 61 * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc. 62 * The returned value should be free()d when done to avoid memory leaks. 63 * 64 * The state can be placed in a user supplied buffer 'mem': 65 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, 66 * then the function places the cfg in mem and the size used in *lenmem 67 * and returns mem. 68 * 69 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), 70 * then the function returns NULL and places the minimum cfg 71 * buffer size in *lenmem. 72 * */ 73 74 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 75 76 /* 77 * kiss_fft(cfg,in_out_buf) 78 * 79 * Perform an FFT on a complex input buffer. 80 * for a forward FFT, 81 * fin should be f[0] , f[1] , ... ,f[nfft-1] 82 * fout will be F[0] , F[1] , ... ,F[nfft-1] 83 * Note that each element is complex and can be accessed like 84 f[k].r and f[k].i 85 * */ 86 void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); 87 88 /* 89 A more generic version of the above function. It reads its input from every Nth sample. 90 * */ 91 void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride); 92 93 /* If kiss_fft_alloc allocated a buffer, it is one contiguous 94 buffer and can be simply free()d when no longer needed*/ 95 #define kiss_fft_free speex_free 96 97 /* 98 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 99 your compiler output to call this before you exit. 100 */ 101 void kiss_fft_cleanup(void); 102 103 104 #ifdef __cplusplus 105 } 106 #endif 107 108 #endif 109
