00001 #ifndef KISS_FFT_H 00002 #define KISS_FFT_H 00003 00004 #include <stdlib.h> 00005 #include <stdio.h> 00006 #include <math.h> 00007 #include <memory.h> 00008 #include <malloc.h> 00009 00010 #ifdef __cplusplus 00011 extern "C" { 00012 #endif 00013 00014 /* 00015 ATTENTION! 00016 If you would like a : 00017 -- a utility that will handle the caching of fft objects 00018 -- real-only (no imaginary time component ) FFT 00019 -- a multi-dimensional FFT 00020 -- a command-line utility to perform ffts 00021 -- a command-line utility to perform fast-convolution filtering 00022 00023 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c 00024 in the tools/ directory. 00025 */ 00026 00027 #ifdef USE_SIMD 00028 # include <xmmintrin.h> 00029 # define kiss_fft_scalar __m128 00030 #define KISS_FFT_MALLOC(nbytes) memalign(16,nbytes) 00031 #else 00032 #define KISS_FFT_MALLOC malloc 00033 #endif 00034 00035 00036 #ifdef FIXED_POINT 00037 #include <sys/types.h> 00038 # define kiss_fft_scalar int16_t 00039 #else 00040 # ifndef kiss_fft_scalar 00041 /* default is float */ 00042 # define kiss_fft_scalar float 00043 # endif 00044 #endif 00045 00046 typedef struct { 00047 kiss_fft_scalar r; 00048 kiss_fft_scalar i; 00049 }kiss_fft_cpx; 00050 00051 typedef struct kiss_fft_state* kiss_fft_cfg; 00052 00053 /* 00054 * kiss_fft_alloc 00055 * 00056 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. 00057 * 00058 * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL); 00059 * 00060 * The return value from fft_alloc is a cfg buffer used internally 00061 * by the fft routine or NULL. 00062 * 00063 * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc. 00064 * The returned value should be free()d when done to avoid memory leaks. 00065 * 00066 * The state can be placed in a user supplied buffer 'mem': 00067 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, 00068 * then the function places the cfg in mem and the size used in *lenmem 00069 * and returns mem. 00070 * 00071 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), 00072 * then the function returns NULL and places the minimum cfg 00073 * buffer size in *lenmem. 00074 * */ 00075 00076 kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); 00077 00078 /* 00079 * kiss_fft(cfg,in_out_buf) 00080 * 00081 * Perform an FFT on a complex input buffer. 00082 * for a forward FFT, 00083 * fin should be f[0] , f[1] , ... ,f[nfft-1] 00084 * fout will be F[0] , F[1] , ... ,F[nfft-1] 00085 * Note that each element is complex and can be accessed like 00086 f[k].r and f[k].i 00087 * */ 00088 void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); 00089 00090 /* 00091 A more generic version of the above function. It reads its input from every Nth sample. 00092 * */ 00093 void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride); 00094 00095 /* If kiss_fft_alloc allocated a buffer, it is one contiguous 00096 buffer and can be simply free()d when no longer needed*/ 00097 #define kiss_fft_free free 00098 00099 /* 00100 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 00101 your compiler output to call this before you exit. 00102 */ 00103 void kiss_fft_cleanup(void); 00104 00105 00106 #ifdef __cplusplus 00107 } 00108 #endif 00109 00110 #endif