ref: 5b50f4bf81d532de20bc07be795a7787348bcadd
dir: /libcelt/kiss_fft.h/
#ifndef KISS_FFT_H #define KISS_FFT_H #include <stdlib.h> #include <math.h> #include "arch.h" #ifdef __cplusplus extern "C" { #endif /* ATTENTION! If you would like a : -- a utility that will handle the caching of fft objects -- real-only (no imaginary time component ) FFT -- a multi-dimensional FFT -- a command-line utility to perform ffts -- a command-line utility to perform fast-convolution filtering Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c in the tools/ directory. */ #ifdef USE_SIMD # include <xmmintrin.h> # define kiss_fft_scalar __m128 #define KISS_FFT_MALLOC(nbytes) memalign(16,nbytes) #else #define KISS_FFT_MALLOC celt_alloc #endif #ifdef FIXED_POINT #include "arch.h" # define kiss_fft_scalar spx_int16_t #else # ifndef kiss_fft_scalar /* default is float */ # define kiss_fft_scalar float # endif #endif typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; typedef struct kiss_fft_state* kiss_fft_cfg; /* * kiss_fft_alloc * * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. * * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL); * * The return value from fft_alloc is a cfg buffer used internally * by the fft routine or NULL. * * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc. * The returned value should be free()d when done to avoid memory leaks. * * The state can be placed in a user supplied buffer 'mem': * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, * then the function places the cfg in mem and the size used in *lenmem * and returns mem. * * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), * then the function returns NULL and places the minimum cfg * buffer size in *lenmem. * */ kiss_fft_cfg kiss_fft_alloc(int nfft,void * mem,size_t * lenmem); /* * kiss_fft(cfg,in_out_buf) * * Perform an FFT on a complex input buffer. * for a forward FFT, * fin should be f[0] , f[1] , ... ,f[nfft-1] * fout will be F[0] , F[1] , ... ,F[nfft-1] * Note that each element is complex and can be accessed like f[k].r and f[k].i * */ void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); void kiss_ifft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); /* A more generic version of the above function. It reads its input from every Nth sample. * */ void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride); void kiss_ifft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride); /* If kiss_fft_alloc allocated a buffer, it is one contiguous buffer and can be simply free()d when no longer needed*/ #define kiss_fft_free celt_free /* Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up your compiler output to call this before you exit. */ void kiss_fft_cleanup(void); #ifdef __cplusplus } #endif #endif