source: src/scale.c @ f72a10d

/*
         Copyright (C) 2003 Paul Brossier

         This program 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 2 of the License, or
         (at your option) any later version.

         This program 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 this program; if not, write to the Free Software
         Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
         */

#include "aubio_priv.h"
#include "sample.h"
#include "scale.h"

struct _aubio_scale_t {
        smpl_t ilow;
        smpl_t ihig;
        smpl_t olow;
        smpl_t ohig;

        smpl_t scaler;
        smpl_t irange;
        
        /* not implemented yet : type in/out data
        bool inint;
        bool outint;
        */
};


/********************************************************
 * Object Memory Allocation
 */

static aubio_scale_t * aubio_scale_malloc(void);
static void aubio_scale_free(aubio_scale_t * s);

aubio_scale_t * aubio_scale_malloc() {
        aubio_scale_t * s = AUBIO_NEW(aubio_scale_t);
        return s;
}

void aubio_scale_free(aubio_scale_t * s) {
        AUBIO_FREE(s);
}

/***
 * Object creation/deletion calls
 */
aubio_scale_t * new_aubio_scale (smpl_t ilow, smpl_t ihig, smpl_t olow, smpl_t ohig     ){
        aubio_scale_t * s = aubio_scale_malloc();
        aubio_scale_set (s, ilow, ihig, olow, ohig);
        return s;       
}

void del_aubio_scale(aubio_scale_t *s) {
        aubio_scale_free(s);
}

/***
 * set parmams
 */
void aubio_scale_set (aubio_scale_t *s, smpl_t ilow, smpl_t ihig, smpl_t olow, smpl_t ohig) 
{
        smpl_t inputrange = ihig - ilow;
        smpl_t outputrange= ohig - olow;
        s->ilow = ilow;
        s->ihig = ihig;
        s->olow = olow;
        s->ohig = ohig;
        if (inputrange == 0 )
                s->scaler = 0.0f;
        else {
                s->scaler = outputrange/inputrange;
                if (inputrange < 0 )
                        inputrange = inputrange * -1.0f;
        }
}

/***
 * do it
 */
void aubio_scale_do (aubio_scale_t *s, fvec_t *input) 
{
        uint_t i, j;
        for (i=0; i < input->channels; i++){
                for (j=0;  j < input->length; j++){
                        input->data[i][j] -= s->ilow;
                        input->data[i][j] *= s->scaler;
                        input->data[i][j] += s->olow;
                }
        }
}