source: src/temporal/filter.c @ a54502c

feature/autosinkfeature/cnnfeature/cnn_orgfeature/constantqfeature/crepefeature/crepe_orgfeature/pitchshiftfeature/pydocstringsfeature/timestretchfix/ffmpeg5pitchshiftsamplertimestretchyinfft+
Last change on this file since a54502c was a54502c, checked in by Paul Brossier <piem@piem.org>, 15 years ago

src/temporal/filter.{c,h}: indent, update copyright and license

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File size: 3.7 KB
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1/*
2  Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>
3
4  This file is part of aubio.
5
6  aubio is free software: you can redistribute it and/or modify
7  it under the terms of the GNU General Public License as published by
8  the Free Software Foundation, either version 3 of the License, or
9  (at your option) any later version.
10
11  aubio is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  GNU General Public License for more details.
15
16  You should have received a copy of the GNU General Public License
17  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
18
19*/
20
21
22/* Requires lsmp_t to be long or double. float will NOT give reliable
23 * results */
24
25#include "aubio_priv.h"
26#include "fvec.h"
27#include "lvec.h"
28#include "mathutils.h"
29#include "temporal/filter.h"
30
31struct _aubio_filter_t
32{
33  uint_t order;
34  uint_t samplerate;
35  lvec_t *a;
36  lvec_t *b;
37  lvec_t *y;
38  lvec_t *x;
39};
40
41void
42aubio_filter_do_outplace (aubio_filter_t * f, fvec_t * in, fvec_t * out)
43{
44  fvec_copy (in, out);
45  aubio_filter_do (f, out);
46}
47
48void
49aubio_filter_do (aubio_filter_t * f, fvec_t * in)
50{
51  uint_t i, j, l, order = f->order;
52  lsmp_t *x;
53  lsmp_t *y;
54  lsmp_t *a = f->a->data[0];
55  lsmp_t *b = f->b->data[0];
56
57  for (i = 0; i < in->channels; i++) {
58    x = f->x->data[i];
59    y = f->y->data[i];
60    for (j = 0; j < in->length; j++) {
61      /* new input */
62      x[0] = KILL_DENORMAL (in->data[i][j]);
63      y[0] = b[0] * x[0];
64      for (l = 1; l < order; l++) {
65        y[0] += b[l] * x[l];
66        y[0] -= a[l] * y[l];
67      }
68      /* new output */
69      in->data[i][j] = y[0];
70      /* store for next sample */
71      for (l = order - 1; l > 0; l--) {
72        x[l] = x[l - 1];
73        y[l] = y[l - 1];
74      }
75    }
76    /* store for next run */
77    f->x->data[i] = x;
78    f->y->data[i] = y;
79  }
80}
81
82/* 
83 *
84 * despite mirroring, end effects destroy both phse and amplitude. the longer
85 * the buffer, the less affected they are.
86 *
87 * replacing with zeros clicks.
88 *
89 * seems broken for order > 4 (see biquad_do_filtfilt for audible one)
90 */
91void aubio_filter_do_filtfilt(aubio_filter_t * f, fvec_t * in, fvec_t * tmp) {
92  uint_t j,i=0;
93  uint_t length = in->length;
94  //uint_t order = f->order;
95  //lsmp_t mir;
96  /* mirroring */
97  //mir = 2*in->data[i][0];
98  //for (j=1;j<order;j++)
99  //f->x[j] = 0.;//mir - in->data[i][order-j];
100  /* apply filtering */
101  aubio_filter_do(f,in);
102  /* invert */
103  for (j = 0; j < length; j++)
104    tmp->data[i][length-j-1] = in->data[i][j];
105  /* mirror inverted */
106  //mir = 2*tmp->data[i][0];
107  //for (j=1;j<order;j++)
108  //f->x[j] = 0.;//mir - tmp->data[i][order-j];
109  /* apply filtering on inverted */
110  aubio_filter_do(f,tmp);
111  /* invert back */
112  for (j = 0; j < length; j++)
113    in->data[i][j] = tmp->data[i][length-j-1];
114}
115
116lvec_t *
117aubio_filter_get_feedback (aubio_filter_t * f)
118{
119  return f->a;
120}
121
122lvec_t *
123aubio_filter_get_feedforward (aubio_filter_t * f)
124{
125  return f->b;
126}
127
128uint_t
129aubio_filter_get_order (aubio_filter_t * f)
130{
131  return f->order;
132}
133
134uint_t
135aubio_filter_get_samplerate (aubio_filter_t * f)
136{
137  return f->samplerate;
138}
139
140aubio_filter_t *
141new_aubio_filter (uint_t samplerate, uint_t order, uint_t channels)
142{
143  aubio_filter_t *f = AUBIO_NEW (aubio_filter_t);
144  f->x = new_lvec (order, channels);
145  f->y = new_lvec (order, channels);
146  f->a = new_lvec (order, 1);
147  f->b = new_lvec (order, 1);
148  f->samplerate = samplerate;
149  f->order = order;
150  /* set default to identity */
151  f->a->data[0][1] = 1.;
152  return f;
153}
154
155void
156del_aubio_filter (aubio_filter_t * f)
157{
158  del_lvec (f->a);
159  del_lvec (f->b);
160  del_lvec (f->x);
161  del_lvec (f->y);
162  AUBIO_FREE (f);
163  return;
164}
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