mirror of
https://github.com/mborgerding/kissfft.git
synced 2025-05-27 21:20:27 -04:00
78 lines
2.1 KiB
C
78 lines
2.1 KiB
C
#ifndef KISS_FFT_H
|
|
#define KISS_FFT_H
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <math.h>
|
|
#include <memory.h>
|
|
|
|
/*
|
|
ATTENTION!
|
|
If you would like a :
|
|
-- a utility that will handle the caching of fft objects
|
|
-- real-only FFT
|
|
-- a multi-dimensional FFT
|
|
-- a command-line utility to perform ffts
|
|
-- a command-line utility to perform fast-convolution filtering
|
|
|
|
then see tools/
|
|
*/
|
|
|
|
#ifdef FIXED_POINT
|
|
# define kiss_fft_scalar short
|
|
#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;
|
|
|
|
/*
|
|
* kiss_fft_alloc
|
|
*
|
|
* Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
|
|
*
|
|
* typical usage: void * 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.
|
|
* */
|
|
void* kiss_fft_alloc(int nfft,int inverse_fft,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(const void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
|
|
|
|
void kiss_fft_stride(const void * 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 free
|
|
|
|
#endif
|