ref: 4123f16136372509b6b4d766f1837cbd55432678
dir: /src/temporal/filter.c/
/*
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.
*/
/* Requires lsmp_t to be long or double. float will NOT give reliable
* results */
#include "aubio_priv.h"
#include "fvec.h"
#include "mathutils.h"
#include "temporal/filter.h"
#include "temporal/filter_priv.h"
/* bug: mono only */
void aubio_filter_do(aubio_filter_t * f, fvec_t * in) {
uint_t i,j,l, order = f->order;
lsmp_t *x = f->x;
lsmp_t *y = f->y;
lsmp_t *a = f->a;
lsmp_t *b = f->b;
i=0;//for (i=0;i<in->channels;i++) {
for (j = 0; j < in->length; j++) {
/* new input */
//AUBIO_DBG("befor %f\t", in->data[i][j]);
x[0] = in->data[i][j];
y[0] = b[0] * x[0];
for (l=1;l<order; l++) {
y[0] += b[l] * x[l];
y[0] -= a[l] * y[l];
} /* + 1e-37; for denormal ? */
/* new output */
in->data[i][j] = y[0];
//AUBIO_DBG("after %f\n", in->data[i][j]);
/* store states for next sample */
for (l=order-1; l>0; l--){
x[l] = x[l-1];
y[l] = y[l-1];
}
}
/* store states for next buffer */
f->x = x;
f->y = y;
//}
}
void aubio_filter_do_outplace(aubio_filter_t * f, fvec_t * in, fvec_t * out) {
uint_t i,j,l, order = f->order;
lsmp_t *x = f->x;
lsmp_t *y = f->y;
lsmp_t *a = f->a;
lsmp_t *b = f->b;
i=0; // works in mono only !!!
//for (i=0;i<in->channels;i++) {
for (j = 0; j < in->length; j++) {
/* new input */
x[0] = in->data[i][j];
y[0] = b[0] * x[0];
for (l=1;l<order; l++) {
y[0] += b[l] * x[l];
y[0] -= a[l] * y[l];
}
// + 1e-37;
/* new output */
out->data[i][j] = y[0];
/* store for next sample */
for (l=order-1; l>0; l--){
x[l] = x[l-1];
y[l] = y[l-1];
}
}
/* store for next run */
f->x = x;
f->y = y;
//}
}
/*
*
* despite mirroring, end effects destroy both phse and amplitude. the longer
* the buffer, the less affected they are.
*
* replacing with zeros clicks.
*
* seems broken for order > 4 (see biquad_do_filtfilt for audible one)
*/
void aubio_filter_do_filtfilt(aubio_filter_t * f, fvec_t * in, fvec_t * tmp) {
uint_t j,i=0;
uint_t length = in->length;
//uint_t order = f->order;
//lsmp_t mir;
/* mirroring */
//mir = 2*in->data[i][0];
//for (j=1;j<order;j++)
//f->x[j] = 0.;//mir - in->data[i][order-j];
/* apply filtering */
aubio_filter_do(f,in);
/* invert */
for (j = 0; j < length; j++)
tmp->data[i][length-j-1] = in->data[i][j];
/* mirror inverted */
//mir = 2*tmp->data[i][0];
//for (j=1;j<order;j++)
//f->x[j] = 0.;//mir - tmp->data[i][order-j];
/* apply filtering on inverted */
aubio_filter_do(f,tmp);
/* invert back */
for (j = 0; j < length; j++)
in->data[i][j] = tmp->data[i][length-j-1];
}
aubio_filter_t * new_aubio_filter(uint_t samplerate UNUSED, uint_t order) {
aubio_filter_t * f = AUBIO_NEW(aubio_filter_t);
lsmp_t * x = f->x;
lsmp_t * y = f->y;
lsmp_t * a = f->a;
lsmp_t * b = f->b;
uint_t l;
f->order = order;
a = AUBIO_ARRAY(lsmp_t,f->order);
b = AUBIO_ARRAY(lsmp_t,f->order);
x = AUBIO_ARRAY(lsmp_t,f->order);
y = AUBIO_ARRAY(lsmp_t,f->order);
/* initial states to zeros */
for (l=0; l<f->order; l++){
x[l] = 0.;
y[l] = 0.;
}
f->x = x;
f->y = y;
f->a = a;
f->b = b;
return f;
}
void del_aubio_filter(aubio_filter_t * f) {
AUBIO_FREE(f->a);
AUBIO_FREE(f->b);
AUBIO_FREE(f->x);
AUBIO_FREE(f->y);
AUBIO_FREE(f);
return;
}