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 | void aubio_filterbank_set_mel_coeffs(aubio_filterbank_t *fb, uint_t samplerate, smpl_t freq_min, smpl_t freq_max){ |
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29 | |
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30 | fvec_t *filters = aubio_filterbank_get_coeffs(fb); |
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31 | uint_t n_filters = filters->channels, win_s = filters->length; |
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32 | |
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33 | //slaney params |
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34 | smpl_t lowestFrequency = 133.3333; |
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35 | smpl_t linearSpacing = 66.66666666; |
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36 | smpl_t logSpacing = 1.0711703; |
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37 | |
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38 | uint_t linearFilters = 13; |
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39 | uint_t logFilters = 27; |
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40 | uint_t allFilters = linearFilters + logFilters; |
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41 | |
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42 | //buffers for computing filter frequencies |
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43 | fvec_t * freqs=new_fvec(allFilters+2 , 1); |
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44 | |
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45 | fvec_t * lower_freqs=new_fvec( allFilters, 1); |
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46 | fvec_t * upper_freqs=new_fvec( allFilters, 1); |
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47 | fvec_t * center_freqs=new_fvec( allFilters, 1); |
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48 | |
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49 | fvec_t * triangle_heights=new_fvec( allFilters, 1); |
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50 | //lookup table of each bin frequency in hz |
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51 | fvec_t * fft_freqs=new_fvec(win_s, 1); |
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52 | |
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53 | uint_t filter_cnt, bin_cnt; |
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54 | |
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55 | //first step: filling all the linear filter frequencies |
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56 | for(filter_cnt=0; filter_cnt<linearFilters; filter_cnt++){ |
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57 | freqs->data[0][filter_cnt]=lowestFrequency+ filter_cnt*linearSpacing; |
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58 | } |
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59 | smpl_t lastlinearCF=freqs->data[0][filter_cnt-1]; |
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60 | |
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61 | //second step: filling all the log filter frequencies |
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62 | for(filter_cnt=0; filter_cnt<logFilters+2; filter_cnt++){ |
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63 | freqs->data[0][filter_cnt+linearFilters] = |
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64 | lastlinearCF*(pow(logSpacing,filter_cnt+1)); |
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65 | } |
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66 | |
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67 | //Option 1. copying interesting values to lower_freqs, center_freqs and upper freqs arrays |
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68 | //TODO: would be nicer to have a reference to freqs->data, anyway we do not care in this init step |
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69 | |
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70 | for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){ |
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71 | lower_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt]; |
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72 | center_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt+1]; |
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73 | upper_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt+2]; |
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74 | } |
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75 | |
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76 | //computing triangle heights so that each triangle has unit area |
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77 | for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){ |
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78 | triangle_heights->data[0][filter_cnt] = 2./(upper_freqs->data[0][filter_cnt] |
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79 | - lower_freqs->data[0][filter_cnt]); |
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80 | } |
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81 | |
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82 | //AUBIO_DBG("filter tables frequencies\n"); |
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83 | //for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++) |
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84 | // AUBIO_DBG("filter n. %d %f %f %f %f\n", |
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85 | // filter_cnt, lower_freqs->data[0][filter_cnt], |
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86 | // center_freqs->data[0][filter_cnt], upper_freqs->data[0][filter_cnt], |
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87 | // triangle_heights->data[0][filter_cnt]); |
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88 | |
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89 | //filling the fft_freqs lookup table, which assigns the frequency in hz to each bin |
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90 | for(bin_cnt=0; bin_cnt<win_s; bin_cnt++){ |
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91 | fft_freqs->data[0][bin_cnt]= aubio_bintofreq(bin_cnt, samplerate, win_s); |
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92 | } |
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93 | |
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94 | //building each filter table |
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95 | for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){ |
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96 | |
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97 | //TODO:check special case : lower freq =0 |
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98 | //calculating rise increment in mag/Hz |
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99 | smpl_t riseInc= triangle_heights->data[0][filter_cnt]/(center_freqs->data[0][filter_cnt]-lower_freqs->data[0][filter_cnt]); |
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100 | |
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101 | //zeroing begining of filter |
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102 | for(bin_cnt=0; bin_cnt<win_s-1; bin_cnt++){ |
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103 | filters->data[filter_cnt][bin_cnt]=0.0; |
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104 | if( fft_freqs->data[0][bin_cnt] <= lower_freqs->data[0][filter_cnt] && |
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105 | fft_freqs->data[0][bin_cnt+1] > lower_freqs->data[0][filter_cnt]) { |
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106 | break; |
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107 | } |
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108 | } |
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109 | bin_cnt++; |
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110 | |
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111 | //positive slope |
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112 | for(; bin_cnt<win_s-1; bin_cnt++){ |
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113 | filters->data[filter_cnt][bin_cnt]=(fft_freqs->data[0][bin_cnt]-lower_freqs->data[0][filter_cnt])*riseInc; |
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114 | //if(fft_freqs->data[0][bin_cnt]<= center_freqs->data[0][filter_cnt] && fft_freqs->data[0][bin_cnt+1]> center_freqs->data[0][filter_cnt]) |
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115 | if(fft_freqs->data[0][bin_cnt+1]> center_freqs->data[0][filter_cnt]) |
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116 | break; |
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117 | } |
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118 | //bin_cnt++; |
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119 | |
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120 | //negative slope |
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121 | for(; bin_cnt<win_s-1; bin_cnt++){ |
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122 | |
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123 | //checking whether last value is less than 0... |
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124 | smpl_t val=triangle_heights->data[0][filter_cnt]-(fft_freqs->data[0][bin_cnt]-center_freqs->data[0][filter_cnt])*riseInc; |
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125 | if(val>=0) |
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126 | filters->data[filter_cnt][bin_cnt]=val; |
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127 | else filters->data[filter_cnt][bin_cnt]=0.0; |
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128 | |
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129 | //if(fft_freqs->data[0][bin_cnt]<= upper_freqs->data[0][bin_cnt] && fft_freqs->data[0][bin_cnt+1]> upper_freqs->data[0][filter_cnt]) |
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130 | //TODO: CHECK whether bugfix correct |
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131 | if(fft_freqs->data[0][bin_cnt+1]> upper_freqs->data[0][filter_cnt]) |
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132 | break; |
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133 | } |
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134 | //bin_cnt++; |
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135 | |
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136 | //zeroing tail |
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137 | for(; bin_cnt<win_s; bin_cnt++) |
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138 | filters->data[filter_cnt][bin_cnt]=0.f; |
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139 | |
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140 | } |
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141 | |
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142 | /* destroy temporarly allocated vectors */ |
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143 | del_fvec(freqs); |
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144 | del_fvec(lower_freqs); |
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145 | del_fvec(upper_freqs); |
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146 | del_fvec(center_freqs); |
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147 | |
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148 | del_fvec(triangle_heights); |
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149 | del_fvec(fft_freqs); |
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150 | |
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151 | } |
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152 | |
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