1 | /* |
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2 | Copyright (C) 2005-2009 Matthew Davies and Paul Brossier <piem@aubio.org> |
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3 | |
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4 | This file is part of aubio. |
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5 | |
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6 | aubio is free software: you can redistribute it and/or modify |
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7 | it under the terms of the GNU General Public License as published by |
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8 | the Free Software Foundation, either version 3 of the License, or |
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9 | (at your option) any later version. |
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10 | |
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11 | aubio is distributed in the hope that it will be useful, |
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | GNU General Public License for more details. |
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15 | |
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16 | You should have received a copy of the GNU General Public License |
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17 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
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18 | |
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19 | */ |
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20 | |
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21 | #include "aubio_priv.h" |
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22 | #include "fvec.h" |
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23 | #include "mathutils.h" |
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24 | #include "tempo/beattracking.h" |
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25 | |
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26 | /** define to 1 to print out tracking difficulties */ |
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27 | #define AUBIO_BEAT_WARNINGS 0 |
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28 | |
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29 | uint_t fvec_gettimesig (fvec_t * acf, uint_t acflen, uint_t gp); |
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30 | void aubio_beattracking_checkstate (aubio_beattracking_t * bt); |
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31 | |
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32 | struct _aubio_beattracking_t |
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33 | { |
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34 | fvec_t *rwv; /** rayleigh weighting for beat period in general model */ |
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35 | fvec_t *dfwv; /** exponential weighting for beat alignment in general model */ |
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36 | fvec_t *gwv; /** gaussian weighting for beat period in context dependant model */ |
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37 | fvec_t *phwv; /** gaussian weighting for beat alignment in context dependant model */ |
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38 | fvec_t *dfrev; /** reversed onset detection function */ |
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39 | fvec_t *acf; /** vector for autocorrelation function (of current detection function frame) */ |
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40 | fvec_t *acfout; /** store result of passing acf through s.i.c.f.b. */ |
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41 | fvec_t *phout; |
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42 | uint_t timesig; /** time signature of input, set to zero until context dependent model activated */ |
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43 | uint_t step; |
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44 | uint_t rayparam; /** Rayleigh parameter */ |
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45 | smpl_t lastbeat; |
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46 | sint_t counter; |
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47 | uint_t flagstep; |
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48 | smpl_t g_var; |
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49 | smpl_t gp; |
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50 | smpl_t bp; |
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51 | smpl_t rp; |
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52 | smpl_t rp1; |
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53 | smpl_t rp2; |
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54 | }; |
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55 | |
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56 | aubio_beattracking_t * |
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57 | new_aubio_beattracking (uint_t winlen) |
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58 | { |
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59 | |
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60 | aubio_beattracking_t *p = AUBIO_NEW (aubio_beattracking_t); |
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61 | uint_t i = 0; |
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62 | /* parameter for rayleigh weight vector - sets preferred tempo to |
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63 | * 120bpm [43] */ |
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64 | smpl_t rayparam = 48. / 512. * winlen; |
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65 | smpl_t dfwvnorm = EXP ((LOG (2.0) / rayparam) * (winlen + 2)); |
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66 | /* length over which beat period is found [128] */ |
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67 | uint_t laglen = winlen / 4; |
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68 | /* step increment - both in detection function samples -i.e. 11.6ms or |
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69 | * 1 onset frame [128] */ |
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70 | uint_t step = winlen / 4; /* 1.5 seconds */ |
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71 | |
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72 | p->lastbeat = 0; |
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73 | p->counter = 0; |
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74 | p->flagstep = 0; |
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75 | p->g_var = 3.901; // constthresh empirically derived! |
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76 | p->rp = 1; |
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77 | p->gp = 0; |
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78 | |
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79 | p->rayparam = rayparam; |
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80 | p->step = step; |
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81 | p->rwv = new_fvec (laglen); |
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82 | p->gwv = new_fvec (laglen); |
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83 | p->dfwv = new_fvec (winlen); |
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84 | p->dfrev = new_fvec (winlen); |
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85 | p->acf = new_fvec (winlen); |
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86 | p->acfout = new_fvec (laglen); |
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87 | p->phwv = new_fvec (2 * laglen); |
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88 | p->phout = new_fvec (winlen); |
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89 | |
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90 | p->timesig = 0; |
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91 | |
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92 | /* exponential weighting, dfwv = 0.5 when i = 43 */ |
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93 | for (i = 0; i < winlen; i++) { |
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94 | p->dfwv->data[i] = (EXP ((LOG (2.0) / rayparam) * (i + 1))) |
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95 | / dfwvnorm; |
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96 | } |
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97 | |
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98 | for (i = 0; i < (laglen); i++) { |
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99 | p->rwv->data[i] = ((smpl_t) (i + 1.) / SQR ((smpl_t) rayparam)) * |
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100 | EXP ((-SQR ((smpl_t) (i + 1.)) / (2. * SQR ((smpl_t) rayparam)))); |
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101 | } |
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102 | |
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103 | return p; |
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104 | |
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105 | } |
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106 | |
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107 | void |
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108 | del_aubio_beattracking (aubio_beattracking_t * p) |
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109 | { |
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110 | del_fvec (p->rwv); |
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111 | del_fvec (p->gwv); |
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112 | del_fvec (p->dfwv); |
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113 | del_fvec (p->dfrev); |
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114 | del_fvec (p->acf); |
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115 | del_fvec (p->acfout); |
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116 | del_fvec (p->phwv); |
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117 | del_fvec (p->phout); |
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118 | AUBIO_FREE (p); |
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119 | } |
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120 | |
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121 | |
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122 | void |
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123 | aubio_beattracking_do (aubio_beattracking_t * bt, fvec_t * dfframe, |
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124 | fvec_t * output) |
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125 | { |
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126 | |
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127 | uint_t i, k; |
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128 | uint_t step = bt->step; |
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129 | uint_t laglen = bt->rwv->length; |
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130 | uint_t winlen = bt->dfwv->length; |
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131 | uint_t maxindex = 0; |
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132 | //number of harmonics in shift invariant comb filterbank |
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133 | uint_t numelem = 4; |
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134 | |
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135 | smpl_t phase; // beat alignment (step - lastbeat) |
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136 | smpl_t beat; // beat position |
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137 | smpl_t bp; // beat period |
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138 | uint_t a, b; // used to build shift invariant comb filterbank |
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139 | uint_t kmax; // number of elements used to find beat phase |
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140 | |
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141 | /* copy dfframe, apply detection function weighting, and revert */ |
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142 | fvec_copy (dfframe, bt->dfrev); |
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143 | fvec_weight (bt->dfrev, bt->dfwv); |
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144 | fvec_rev (bt->dfrev); |
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145 | |
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146 | /* compute autocorrelation function */ |
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147 | aubio_autocorr (dfframe, bt->acf); |
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148 | |
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149 | /* if timesig is unknown, use metrically unbiased version of filterbank */ |
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150 | if (!bt->timesig) { |
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151 | numelem = 4; |
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152 | } else { |
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153 | numelem = bt->timesig; |
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154 | } |
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155 | |
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156 | /* first and last output values are left intentionally as zero */ |
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157 | fvec_zeros (bt->acfout); |
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158 | |
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159 | /* compute shift invariant comb filterbank */ |
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160 | for (i = 1; i < laglen - 1; i++) { |
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161 | for (a = 1; a <= numelem; a++) { |
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162 | for (b = 1; b < 2 * a; b++) { |
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163 | bt->acfout->data[i] += bt->acf->data[i * a + b - 1] |
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164 | * 1. / (2. * a - 1.); |
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165 | } |
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166 | } |
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167 | } |
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168 | /* apply Rayleigh weight */ |
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169 | fvec_weight (bt->acfout, bt->rwv); |
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170 | |
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171 | /* find non-zero Rayleigh period */ |
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172 | maxindex = fvec_max_elem (bt->acfout); |
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173 | bt->rp = maxindex ? fvec_quadratic_peak_pos (bt->acfout, maxindex) : 1; |
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174 | //rp = (maxindex==127) ? 43 : maxindex; //rayparam |
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175 | bt->rp = (maxindex == bt->acfout->length - 1) ? bt->rayparam : maxindex; //rayparam |
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176 | |
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177 | /* activate biased filterbank */ |
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178 | aubio_beattracking_checkstate (bt); |
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179 | #if 0 // debug metronome mode |
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180 | bt->bp = 36.9142; |
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181 | #endif |
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182 | bp = bt->bp; |
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183 | /* end of biased filterbank */ |
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184 | |
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185 | if (bp == 0) { |
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186 | output->data[0] = 0; |
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187 | return; |
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188 | } |
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189 | |
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190 | /* deliberate integer operation, could be set to 3 max eventually */ |
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191 | kmax = FLOOR (winlen / bp); |
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192 | |
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193 | /* initialize output */ |
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194 | fvec_zeros (bt->phout); |
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195 | for (i = 0; i < bp; i++) { |
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196 | for (k = 0; k < kmax; k++) { |
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197 | bt->phout->data[i] += bt->dfrev->data[i + (uint_t) ROUND (bp * k)]; |
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198 | } |
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199 | } |
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200 | fvec_weight (bt->phout, bt->phwv); |
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201 | |
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202 | /* find Rayleigh period */ |
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203 | maxindex = fvec_max_elem (bt->phout); |
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204 | if (maxindex >= winlen - 1) { |
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205 | #if AUBIO_BEAT_WARNINGS |
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206 | AUBIO_WRN ("no idea what this groove's phase is\n"); |
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207 | #endif /* AUBIO_BEAT_WARNINGS */ |
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208 | phase = step - bt->lastbeat; |
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209 | } else { |
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210 | phase = fvec_quadratic_peak_pos (bt->phout, maxindex); |
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211 | } |
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212 | /* take back one frame delay */ |
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213 | phase += 1.; |
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214 | #if 0 // debug metronome mode |
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215 | phase = step - bt->lastbeat; |
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216 | #endif |
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217 | |
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218 | /* reset output */ |
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219 | fvec_zeros (output); |
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220 | |
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221 | i = 1; |
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222 | beat = bp - phase; |
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223 | |
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224 | // AUBIO_DBG ("bp: %f, phase: %f, lastbeat: %f, step: %d, winlen: %d\n", |
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225 | // bp, phase, bt->lastbeat, step, winlen); |
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226 | |
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227 | /* the next beat will be earlier than 60% of the tempo period |
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228 | skip this one */ |
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229 | if ( ( step - bt->lastbeat - phase ) < -0.40 * bp ) { |
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230 | #if AUBIO_BEAT_WARNINGS |
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231 | AUBIO_WRN ("back off-beat error, skipping this beat\n"); |
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232 | #endif /* AUBIO_BEAT_WARNINGS */ |
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233 | beat += bp; |
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234 | } |
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235 | |
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236 | /* start counting the beats */ |
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237 | while (beat + bp < 0) { |
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238 | beat += bp; |
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239 | } |
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240 | |
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241 | if (beat >= 0) { |
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242 | //AUBIO_DBG ("beat: %d, %f, %f\n", i, bp, beat); |
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243 | output->data[i] = beat; |
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244 | i++; |
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245 | } |
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246 | |
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247 | while (beat + bp <= step) { |
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248 | beat += bp; |
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249 | //AUBIO_DBG ("beat: %d, %f, %f\n", i, bp, beat); |
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250 | output->data[i] = beat; |
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251 | i++; |
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252 | } |
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253 | |
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254 | bt->lastbeat = beat; |
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255 | /* store the number of beats in this frame as the first element */ |
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256 | output->data[0] = i; |
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257 | } |
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258 | |
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259 | uint_t |
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260 | fvec_gettimesig (fvec_t * acf, uint_t acflen, uint_t gp) |
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261 | { |
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262 | sint_t k = 0; |
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263 | smpl_t three_energy = 0., four_energy = 0.; |
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264 | if (acflen > 6 * gp + 2) { |
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265 | for (k = -2; k < 2; k++) { |
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266 | three_energy += acf->data[3 * gp + k]; |
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267 | four_energy += acf->data[4 * gp + k]; |
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268 | } |
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269 | } else { |
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270 | /*Expanded to be more accurate in time sig estimation */ |
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271 | for (k = -2; k < 2; k++) { |
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272 | three_energy += acf->data[3 * gp + k] + acf->data[6 * gp + k]; |
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273 | four_energy += acf->data[4 * gp + k] + acf->data[2 * gp + k]; |
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274 | } |
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275 | } |
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276 | return (three_energy > four_energy) ? 3 : 4; |
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277 | } |
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278 | |
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279 | void |
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280 | aubio_beattracking_checkstate (aubio_beattracking_t * bt) |
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281 | { |
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282 | uint_t i, j, a, b; |
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283 | uint_t flagconst = 0; |
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284 | sint_t counter = bt->counter; |
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285 | uint_t flagstep = bt->flagstep; |
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286 | smpl_t gp = bt->gp; |
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287 | smpl_t bp = bt->bp; |
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288 | smpl_t rp = bt->rp; |
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289 | smpl_t rp1 = bt->rp1; |
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290 | smpl_t rp2 = bt->rp2; |
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291 | uint_t laglen = bt->rwv->length; |
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292 | uint_t acflen = bt->acf->length; |
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293 | uint_t step = bt->step; |
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294 | fvec_t *acf = bt->acf; |
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295 | fvec_t *acfout = bt->acfout; |
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296 | |
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297 | if (gp) { |
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298 | // doshiftfbank again only if context dependent model is in operation |
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299 | //acfout = doshiftfbank(acf,gwv,timesig,laglen,acfout); |
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300 | //don't need acfout now, so can reuse vector |
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301 | // gwv is, in first loop, definitely all zeros, but will have |
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302 | // proper values when context dependent model is activated |
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303 | fvec_zeros (acfout); |
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304 | for (i = 1; i < laglen - 1; i++) { |
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305 | for (a = 1; a <= bt->timesig; a++) { |
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306 | for (b = 1; b < 2 * a; b++) { |
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307 | acfout->data[i] += acf->data[i * a + b - 1]; |
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308 | } |
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309 | } |
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310 | } |
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311 | fvec_weight (acfout, bt->gwv); |
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312 | gp = fvec_quadratic_peak_pos (acfout, fvec_max_elem (acfout)); |
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313 | /* |
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314 | while(gp<32) gp =gp*2; |
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315 | while(gp>64) gp = gp/2; |
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316 | */ |
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317 | } else { |
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318 | //still only using general model |
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319 | gp = 0; |
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320 | } |
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321 | |
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322 | //now look for step change - i.e. a difference between gp and rp that |
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323 | // is greater than 2*constthresh - always true in first case, since gp = 0 |
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324 | if (counter == 0) { |
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325 | if (ABS (gp - rp) > 2. * bt->g_var) { |
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326 | flagstep = 1; // have observed step change. |
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327 | counter = 3; // setup 3 frame counter |
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328 | } else { |
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329 | flagstep = 0; |
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330 | } |
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331 | } |
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332 | //i.e. 3rd frame after flagstep initially set |
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333 | if (counter == 1 && flagstep == 1) { |
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334 | //check for consistency between previous beatperiod values |
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335 | if (ABS (2. * rp - rp1 - rp2) < bt->g_var) { |
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336 | //if true, can activate context dependent model |
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337 | flagconst = 1; |
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338 | counter = 0; // reset counter and flagstep |
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339 | } else { |
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340 | //if not consistent, then don't flag consistency! |
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341 | flagconst = 0; |
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342 | counter = 2; // let it look next time |
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343 | } |
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344 | } else if (counter > 0) { |
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345 | //if counter doesn't = 1, |
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346 | counter = counter - 1; |
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347 | } |
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348 | |
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349 | rp2 = rp1; |
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350 | rp1 = rp; |
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351 | |
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352 | if (flagconst) { |
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353 | /* first run of new hypothesis */ |
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354 | gp = rp; |
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355 | bt->timesig = fvec_gettimesig (acf, acflen, gp); |
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356 | for (j = 0; j < laglen; j++) |
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357 | bt->gwv->data[j] = |
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358 | EXP (-.5 * SQR ((smpl_t) (j + 1. - gp)) / SQR (bt->g_var)); |
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359 | flagconst = 0; |
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360 | bp = gp; |
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361 | /* flat phase weighting */ |
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362 | fvec_ones (bt->phwv); |
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363 | } else if (bt->timesig) { |
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364 | /* context dependant model */ |
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365 | bp = gp; |
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366 | /* gaussian phase weighting */ |
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367 | if (step > bt->lastbeat) { |
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368 | for (j = 0; j < 2 * laglen; j++) { |
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369 | bt->phwv->data[j] = |
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370 | EXP (-.5 * SQR ((smpl_t) (1. + j - step + |
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371 | bt->lastbeat)) / (bp / 8.)); |
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372 | } |
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373 | } else { |
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374 | //AUBIO_DBG("NOT using phase weighting as step is %d and lastbeat %d \n", |
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375 | // step,bt->lastbeat); |
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376 | fvec_ones (bt->phwv); |
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377 | } |
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378 | } else { |
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379 | /* initial state */ |
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380 | bp = rp; |
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381 | /* flat phase weighting */ |
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382 | fvec_ones (bt->phwv); |
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383 | } |
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384 | |
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385 | /* do some further checks on the final bp value */ |
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386 | |
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387 | /* if tempo is > 206 bpm, half it */ |
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388 | while (0 < bp && bp < 25) { |
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389 | #if AUBIO_BEAT_WARNINGS |
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390 | AUBIO_WRN ("doubling from %f (%f bpm) to %f (%f bpm)\n", |
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391 | bp, 60.*44100./512./bp, bp/2., 60.*44100./512./bp/2. ); |
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392 | //AUBIO_DBG("warning, halving the tempo from %f\n", 60.*samplerate/hopsize/bp); |
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393 | #endif /* AUBIO_BEAT_WARNINGS */ |
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394 | bp = bp * 2; |
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395 | } |
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396 | |
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397 | //AUBIO_DBG("tempo:\t%3.5f bpm | ", 5168./bp); |
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398 | |
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399 | /* smoothing */ |
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400 | //bp = (uint_t) (0.8 * (smpl_t)bp + 0.2 * (smpl_t)bp2); |
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401 | //AUBIO_DBG("tempo:\t%3.5f bpm smoothed | bp2 %d | bp %d | ", 5168./bp, bp2, bp); |
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402 | //bp2 = bp; |
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403 | //AUBIO_DBG("time signature: %d \n", bt->timesig); |
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404 | bt->counter = counter; |
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405 | bt->flagstep = flagstep; |
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406 | bt->gp = gp; |
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407 | bt->bp = bp; |
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408 | bt->rp1 = rp1; |
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409 | bt->rp2 = rp2; |
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410 | } |
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411 | |
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412 | smpl_t |
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413 | aubio_beattracking_get_bpm (aubio_beattracking_t * bt) |
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414 | { |
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415 | if (bt->bp != 0 && bt->timesig != 0 && bt->counter == 0 && bt->flagstep == 0) { |
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416 | return 5168. / fvec_quadratic_peak_pos (bt->acfout, bt->bp); |
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417 | } else { |
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418 | return 0.; |
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419 | } |
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420 | } |
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421 | |
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422 | smpl_t |
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423 | aubio_beattracking_get_confidence (aubio_beattracking_t * bt) |
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424 | { |
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425 | if (bt->gp) { |
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426 | return fvec_max (bt->acfout); |
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427 | } else { |
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428 | return 0.; |
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429 | } |
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430 | } |
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