1 | /* |
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2 | Copyright (C) 2004, 2005 Mario Lang <mlang@delysid.org> |
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3 | |
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4 | This program is free software; you can redistribute it and/or modify |
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5 | it under the terms of the GNU General Public License as published by |
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6 | the Free Software Foundation; either version 2 of the License, or |
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7 | (at your option) any later version. |
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8 | |
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9 | This program is distributed in the hope that it will be useful, |
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10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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12 | GNU General Public License for more details. |
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13 | |
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14 | You should have received a copy of the GNU General Public License |
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15 | along with this program; if not, write to the Free Software |
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16 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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17 | |
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18 | */ |
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19 | |
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20 | /* |
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21 | |
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22 | This file was taken from the tuneit project, in the file |
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23 | tuneit.c -- Detect fundamental frequency of a sound |
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24 | see http://delysid.org/tuneit.html |
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25 | |
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26 | a fast harmonic comb filter algorithm for pitch tracking |
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27 | |
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28 | */ |
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29 | |
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30 | #include "aubio_priv.h" |
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31 | #include "sample.h" |
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32 | #include "mathutils.h" |
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33 | #include "phasevoc.h" |
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34 | #include "pitchfcomb.h" |
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35 | |
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36 | #define MAX_PEAKS 8 |
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37 | |
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38 | typedef struct { |
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39 | smpl_t freq; |
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40 | smpl_t db; |
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41 | } aubio_fpeak_t; |
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42 | |
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43 | struct _aubio_pitchfcomb_t { |
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44 | uint_t fftSize; |
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45 | uint_t rate; |
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46 | cvec_t * fftOut; |
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47 | fvec_t * fftLastPhase; |
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48 | aubio_pvoc_t * pvoc; |
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49 | }; |
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50 | |
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51 | aubio_pitchfcomb_t * new_aubio_pitchfcomb (uint_t size, uint_t samplerate) |
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52 | { |
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53 | aubio_pitchfcomb_t * p = AUBIO_NEW(aubio_pitchfcomb_t); |
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54 | uint_t overlap_rate = 4; |
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55 | p->rate = samplerate; |
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56 | p->fftSize = size; |
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57 | p->fftOut = new_cvec(size,1); |
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58 | p->fftLastPhase = new_fvec(size,1); |
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59 | p->pvoc = new_aubio_pvoc(size, size/overlap_rate, 1); |
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60 | return p; |
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61 | } |
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62 | |
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63 | /* input must be stepsize long */ |
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64 | smpl_t aubio_pitchfcomb_detect (aubio_pitchfcomb_t * p, fvec_t * input) |
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65 | { |
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66 | uint_t k, l, maxharm = 0, stepSize = input->length; |
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67 | smpl_t freqPerBin = p->rate/(smpl_t)p->fftSize, |
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68 | phaseDifference = TWO_PI*(smpl_t)stepSize/(smpl_t)p->fftSize; |
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69 | aubio_fpeak_t peaks[MAX_PEAKS]; |
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70 | |
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71 | for (k=0; k<MAX_PEAKS; k++) { |
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72 | peaks[k].db = -200.; |
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73 | peaks[k].freq = 0.; |
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74 | } |
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75 | |
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76 | aubio_pvoc_do (p->pvoc, input, p->fftOut); |
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77 | |
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78 | for (k=0; k<=p->fftSize; k++) { |
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79 | //long qpd; |
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80 | smpl_t |
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81 | magnitude = 20.*LOG10(2.*p->fftOut->norm[0][k]/(smpl_t)p->fftSize), |
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82 | phase = p->fftOut->phas[0][k], |
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83 | tmp, freq; |
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84 | |
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85 | /* compute phase difference */ |
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86 | tmp = phase - p->fftLastPhase->data[0][k]; |
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87 | p->fftLastPhase->data[0][k] = phase; |
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88 | |
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89 | /* subtract expected phase difference */ |
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90 | tmp -= (smpl_t)k*phaseDifference; |
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91 | |
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92 | /* map delta phase into +/- Pi interval */ |
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93 | tmp = unwrap2pi(tmp); |
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94 | |
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95 | /* get deviation from bin frequency from the +/- Pi interval */ |
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96 | tmp = p->fftSize/input->length*tmp/(TWO_PI); |
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97 | |
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98 | /* compute the k-th partials' true frequency */ |
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99 | freq = (smpl_t)k*freqPerBin + tmp*freqPerBin; |
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100 | |
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101 | if (freq > 0.0 && magnitude > peaks[0].db && magnitude < 0) { |
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102 | memmove(peaks+1, peaks, sizeof(aubio_fpeak_t)*(MAX_PEAKS-1)); |
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103 | peaks[0].freq = freq; |
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104 | peaks[0].db = magnitude; |
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105 | } |
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106 | } |
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107 | |
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108 | k = 0; |
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109 | for (l=1; l<MAX_PEAKS && peaks[l].freq > 0.0; l++) { |
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110 | sint_t harmonic; |
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111 | for (harmonic=5; harmonic>1; harmonic--) { |
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112 | if (peaks[0].freq / peaks[l].freq < harmonic+.02 && |
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113 | peaks[0].freq / peaks[l].freq > harmonic-.02) { |
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114 | if (harmonic > maxharm && |
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115 | peaks[0].db < peaks[l].db/2) { |
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116 | maxharm = harmonic; |
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117 | k = l; |
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118 | } |
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119 | } |
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120 | } |
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121 | } |
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122 | /* quick hack to clean output a bit */ |
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123 | if (peaks[k].freq > 10000) return 0.; |
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124 | return peaks[k].freq; |
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125 | } |
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126 | |
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127 | void del_aubio_pitchfcomb (aubio_pitchfcomb_t * p) |
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128 | { |
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129 | del_cvec(p->fftOut); |
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130 | del_fvec(p->fftLastPhase); |
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131 | del_aubio_pvoc(p->pvoc); |
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132 | AUBIO_FREE(p); |
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133 | } |
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134 | |
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