1 | /* |
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2 | Copyright (C) 2007-2013 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 | /** \file |
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23 | |
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24 | Filterbank object |
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25 | |
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26 | General-purpose spectral filterbank object. |
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27 | |
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28 | \example spectral/test-filterbank.c |
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29 | |
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30 | */ |
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31 | |
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32 | #ifndef AUBIO_FILTERBANK_H |
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33 | #define AUBIO_FILTERBANK_H |
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34 | |
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35 | #ifdef __cplusplus |
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36 | extern "C" |
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37 | { |
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38 | #endif |
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39 | |
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40 | /** filterbank object |
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41 | |
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42 | This object stores a matrix of spectral filter coefficients. |
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43 | |
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44 | */ |
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45 | typedef struct _aubio_filterbank_t aubio_filterbank_t; |
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46 | |
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47 | /** create filterbank object |
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48 | |
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49 | \param n_filters number of filters to create |
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50 | \param win_s size of analysis buffer (and length the FFT transform) |
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51 | |
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52 | */ |
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53 | aubio_filterbank_t *new_aubio_filterbank (uint_t n_filters, uint_t win_s); |
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54 | |
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55 | /** destroy filterbank object |
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56 | |
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57 | \param f filterbank object, as returned by new_aubio_filterbank() |
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58 | |
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59 | */ |
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60 | void del_aubio_filterbank (aubio_filterbank_t * f); |
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61 | |
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62 | /** compute filterbank |
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63 | |
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64 | \param f filterbank object, as returned by new_aubio_filterbank() |
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65 | \param in input spectrum containing an input spectrum of length `win_s` |
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66 | \param out output vector containing the energy found in each band, `nfilt` output values |
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67 | |
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68 | */ |
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69 | void aubio_filterbank_do (aubio_filterbank_t * f, const cvec_t * in, fvec_t * out); |
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70 | |
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71 | /** return a pointer to the matrix object containing all filter coefficients |
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72 | |
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73 | \param f filterbank object, as returned by new_aubio_filterbank() |
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74 | |
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75 | */ |
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76 | fmat_t *aubio_filterbank_get_coeffs (const aubio_filterbank_t * f); |
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77 | |
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78 | /** copy filter coefficients to the filterbank |
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79 | |
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80 | \param f filterbank object, as returned by new_aubio_filterbank() |
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81 | \param filters filter bank coefficients to copy from |
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82 | |
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83 | */ |
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84 | uint_t aubio_filterbank_set_coeffs (aubio_filterbank_t * f, const fmat_t * filters); |
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85 | |
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86 | /** set norm parameter |
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87 | |
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88 | \param f filterbank object, as returned by new_aubio_filterbank() |
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89 | \param norm `1` to norm the filters, `0` otherwise. |
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90 | |
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91 | If set to `0`, the filters will not be normalized. If set to `1`, |
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92 | each filter will be normalized to one. Defaults to `1`. |
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93 | |
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94 | This function should be called *before* setting the filters with one of |
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95 | aubio_filterbank_set_triangle_bands(), aubio_filterbank_set_mel_coeffs(), |
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96 | aubio_filterbank_set_mel_coeffs_htk(), or |
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97 | aubio_filterbank_set_mel_coeffs_slaney(). |
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98 | |
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99 | */ |
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100 | uint_t aubio_filterbank_set_norm (aubio_filterbank_t *f, smpl_t norm); |
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101 | |
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102 | /** get norm parameter |
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103 | |
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104 | \param f filterbank object, as returned by new_aubio_filterbank() |
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105 | \returns `1` if norm is set, `0` otherwise. Defaults to `1`. |
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106 | |
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107 | */ |
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108 | smpl_t aubio_filterbank_get_norm (aubio_filterbank_t *f); |
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109 | |
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110 | /** set power parameter |
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111 | |
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112 | \param f filterbank object, as returned by new_aubio_filterbank() |
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113 | \param power Raise norm of the input spectrum norm to this power before |
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114 | computing filterbank. Defaults to `1`. |
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115 | |
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116 | */ |
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117 | uint_t aubio_filterbank_set_power (aubio_filterbank_t *f, smpl_t power); |
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118 | |
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119 | /** get power parameter |
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120 | |
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121 | \param f filterbank object, as returned by new_aubio_filterbank() |
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122 | \return current power parameter. Defaults to `1`. |
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123 | |
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124 | */ |
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125 | smpl_t aubio_filterbank_get_power (aubio_filterbank_t *f); |
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126 | |
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127 | #ifdef __cplusplus |
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128 | } |
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129 | #endif |
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130 | |
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131 | #endif /* AUBIO_FILTERBANK_H */ |
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