1 | /* |
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2 | Copyright (C) 2007-2009 Paul Brossier <piem@aubio.org> |
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3 | and Amaury Hazan <ahazan@iua.upf.edu> |
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4 | |
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5 | This file is part of Aubio. |
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6 | |
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7 | Aubio is free software: you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation, either version 3 of the License, or |
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10 | (at your option) any later version. |
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11 | |
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12 | Aubio is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |
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17 | You should have received a copy of the GNU General Public License |
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18 | along with Aubio. If not, see <http://www.gnu.org/licenses/>. |
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19 | |
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20 | */ |
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21 | |
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22 | #include "aubio_priv.h" |
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23 | #include "fvec.h" |
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24 | #include "cvec.h" |
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25 | #include "spectral/filterbank.h" |
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26 | #include "mathutils.h" |
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27 | |
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28 | #define VERY_SMALL_NUMBER 2e-42 |
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29 | |
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30 | /** \brief A structure to store a set of n_filters filters of lenghts win_s */ |
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31 | struct aubio_filterbank_t_ |
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32 | { |
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33 | uint_t win_s; |
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34 | uint_t n_filters; |
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35 | fvec_t *filters; |
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36 | }; |
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37 | |
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38 | aubio_filterbank_t * |
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39 | new_aubio_filterbank (uint_t n_filters, uint_t win_s) |
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40 | { |
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41 | /* allocate space for filterbank object */ |
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42 | aubio_filterbank_t *fb = AUBIO_NEW (aubio_filterbank_t); |
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43 | fb->win_s = win_s; |
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44 | fb->n_filters = n_filters; |
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45 | |
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46 | /* allocate filter tables, an fvec of length win_s and of filter_cnt channel */ |
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47 | fb->filters = new_fvec (win_s, n_filters); |
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48 | |
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49 | return fb; |
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50 | } |
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51 | |
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52 | void |
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53 | del_aubio_filterbank (aubio_filterbank_t * fb) |
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54 | { |
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55 | del_fvec (fb->filters); |
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56 | AUBIO_FREE (fb); |
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57 | } |
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58 | |
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59 | void |
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60 | aubio_filterbank_do (aubio_filterbank_t * f, cvec_t * in, fvec_t * out) |
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61 | { |
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62 | uint_t i, j, fn; |
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63 | |
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64 | /* apply filter to all input channel, provided out has enough channels */ |
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65 | uint_t max_channels = MIN (in->channels, out->channels); |
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66 | uint_t max_filters = MIN (f->n_filters, out->length); |
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67 | |
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68 | /* reset all values in output vector */ |
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69 | fvec_zeros (out); |
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70 | |
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71 | /* apply filters on all channels */ |
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72 | for (i = 0; i < max_channels; i++) { |
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73 | |
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74 | /* for each filter */ |
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75 | for (fn = 0; fn < max_filters; fn++) { |
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76 | |
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77 | /* for each sample */ |
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78 | for (j = 0; j < in->length; j++) { |
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79 | out->data[i][fn] += in->norm[i][j] * f->filters->data[fn][j]; |
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80 | } |
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81 | |
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82 | /* threshold to VERY_SMALL_NUMBER to avoid log oveflow */ |
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83 | out->data[i][fn] = MAX (VERY_SMALL_NUMBER, out->data[i][fn]); |
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84 | |
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85 | /* compute logarithm */ |
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86 | out->data[i][fn] = LOG (out->data[i][fn]); |
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87 | } |
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88 | } |
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89 | |
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90 | return; |
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91 | } |
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92 | |
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93 | fvec_t * |
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94 | aubio_filterbank_get_coeffs (aubio_filterbank_t * f) |
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95 | { |
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96 | return f->filters; |
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97 | } |
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