libdspl-2.0/dspl/src/fft.c

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3.9 KiB
C

/*
* Copyright (c) 2015-2018 Sergey Bakhurin
* Digital Signal Processing Library [http://dsplib.org]
*
* This file is part of libdspl-2.0.
*
* is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* DSPL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Foobar. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "dspl.h"
#include "fftw3.h"
/**************************************************************************************************
Create FFT object
***************************************************************************************************/
int DSPL_API fft_create( fft_t *pfft, int n)
{
if(!pfft)
return ERROR_PTR;
if(n<1)
return ERROR_SIZE;
printf("1\n");
if(pfft->in)
{
if(pfft->size != n)
pfft->in = (complex_t*) realloc(pfft->in, n*sizeof(complex_t));
}
else
pfft->in = (complex_t*) malloc(n*sizeof(complex_t));
if(pfft->out)
{
if(pfft->size != n)
pfft->out = (complex_t*) realloc(pfft->out, n*sizeof(complex_t));
}
else
pfft->out = (complex_t*) malloc(n*sizeof(complex_t));
pfft->size = n;
printf("2\n");
if(pfft->pfftw)
fftw_destroy_plan(pfft->pfftw);
printf("3\n");
pfft->pfftw = (void*)fftw_plan_dft_1d(n, pfft->in, pfft->out, FFTW_FORWARD, FFTW_ESTIMATE);
printf("4\n");
if(!pfft->pfftw)
return ERROR_FFT_CREATE;
return RES_OK;
}
/**************************************************************************************************
Destroy FFT object
***************************************************************************************************/
void DSPL_API fft_destroy(fft_t *pfft)
{
if(pfft)
return;
if(pfft->pfftw)
fftw_destroy_plan(pfft->pfftw);
if(pfft->in)
free(pfft->in);
if(pfft->out)
free(pfft->out);
pfft->size = 0;
}
/**************************************************************************************************
Destroy FFT object
***************************************************************************************************/
int DSPL_API fft_cmplx(complex_t *x, int n, fft_t* pfft, complex_t* y)
{
if(!x || !y || !pfft)
return ERROR_PTR;
if(n<1)
return ERROR_SIZE;
if(n != pfft->size)
fft_create(pfft, n);
memcpy(pfft->in, x, n*sizeof(complex_t));
fftw_execute(pfft->pfftw);
memcpy(y, pfft->out, n*sizeof(complex_t));
return RES_OK;
}
/**************************************************************************************************
FFT shifting
***************************************************************************************************/
int DSPL_API fft_shift(double* x, int n, double* y)
{
int n2, r;
int k;
double tmp;
double *buf;
if(!x || !y)
return ERROR_PTR;
if(n<1)
return ERROR_SIZE;
r = n%2;
if(!r)
{
n2 = n>>1;
for(k = 0; k < n2; k++)
{
tmp = x[k];
y[k] = x[k+n2];
y[k+n2] = tmp;
}
}
else
{
n2 = (n-1) >> 1;
buf = (double*) malloc(n2*sizeof(double));
memcpy(buf, x, n2*sizeof(double));
memcpy(y, x+n2, (n2+1)*sizeof(double));
memcpy(y+n2+1, buf, n2*sizeof(double));
free(buf);
}
return RES_OK;
}