conv.c

/*
* Copyright (c) 2015-2022 Sergey Bakhurin
* Digital Signal Processing Library [http://dsplib.org]
*
* This file is part of DSPL.
*
* is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License
* along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
*/
 
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "dspl.h"
 
 
 
#ifdef DOXYGEN_ENGLISH
#endif
#ifdef DOXYGEN_RUSSIAN
#endif
int DSPL_API conv(double* a, int na, double* b, int nb, double* c)
{
    int k;
    int n;
 
    double *t;
    size_t bufsize;
 
    if(!a || !b || !c)
        return ERROR_PTR;
    if(na < 1 || nb < 1)
        return ERROR_SIZE;
 
 
    bufsize = (na + nb - 1) * sizeof(double);
 
    if((a != c) && (b != c))
        t = c;
    else
        t = (double*)malloc(bufsize);
 
    memset(t, 0, bufsize);
 
    for(k = 0; k < na; k++)
        for(n = 0; n < nb; n++)
            t[k+n] += a[k]*b[n];
 
    if(t!=c)
    {
        memcpy(c, t, bufsize);
        free(t);
    }
    return RES_OK;
}