1 | /* |
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2 | Copyright (C) 2003-2009 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 | /** @file |
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22 | * various math functions |
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23 | * |
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24 | * \todo multichannel (each function should return -or set- an array sized to |
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25 | * the number of channel in the input vector) |
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26 | * |
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27 | * \todo appropriate switches depending on types.h content |
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28 | */ |
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29 | |
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30 | #ifndef MATHUTILS_H |
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31 | #define MATHUTILS_H |
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32 | |
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33 | #ifdef __cplusplus |
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34 | extern "C" { |
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35 | #endif |
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36 | |
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37 | /** Window types |
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38 | * |
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39 | * inspired from |
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40 | * |
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41 | * - dafx : http://profs.sci.univr.it/%7Edafx/Final-Papers/ps/Bernardini.ps.gz |
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42 | * - freqtweak : http://freqtweak.sf.net/ |
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43 | * - extace : http://extace.sf.net/ |
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44 | */ |
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45 | typedef enum { |
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46 | aubio_win_rectangle, |
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47 | aubio_win_hamming, |
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48 | aubio_win_hanning, |
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49 | aubio_win_hanningz, |
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50 | aubio_win_blackman, |
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51 | aubio_win_blackman_harris, |
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52 | aubio_win_gaussian, |
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53 | aubio_win_welch, |
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54 | aubio_win_parzen |
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55 | } aubio_window_type; |
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56 | |
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57 | /** create window */ |
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58 | fvec_t * new_aubio_window(uint_t size, aubio_window_type wintype); |
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59 | |
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60 | /** principal argument |
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61 | * |
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62 | * mod(phase+PI,-TWO_PI)+PI |
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63 | */ |
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64 | smpl_t aubio_unwrap2pi (smpl_t phase); |
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65 | |
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66 | /** calculates the mean of a vector |
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67 | * |
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68 | * \bug mono |
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69 | */ |
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70 | smpl_t fvec_mean(fvec_t *s); |
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71 | /** returns the max of a vector |
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72 | * |
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73 | * \bug mono |
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74 | */ |
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75 | smpl_t fvec_max(fvec_t *s); |
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76 | /** returns the min of a vector |
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77 | * |
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78 | * \bug mono |
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79 | */ |
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80 | smpl_t fvec_min(fvec_t *s); |
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81 | /** returns the index of the min of a vector |
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82 | * |
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83 | * \bug mono |
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84 | */ |
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85 | uint_t fvec_min_elem(fvec_t *s); |
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86 | /** returns the index of the max of a vector |
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87 | * |
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88 | * \bug mono |
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89 | */ |
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90 | uint_t fvec_max_elem(fvec_t *s); |
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91 | /** implement 'fftshift' like function |
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92 | * |
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93 | * a[0]...,a[n/2],a[n/2+1],...a[n] |
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94 | * |
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95 | * becomes |
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96 | * |
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97 | * a[n/2+1],...a[n],a[0]...,a[n/2] |
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98 | */ |
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99 | void fvec_shift(fvec_t *s); |
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100 | /** returns sum */ |
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101 | smpl_t fvec_sum(fvec_t *s); |
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102 | |
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103 | /** returns energy |
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104 | * |
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105 | * \bug mono |
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106 | */ |
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107 | smpl_t fvec_local_energy(fvec_t * f); |
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108 | /** returns High Frequency Energy Content |
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109 | * |
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110 | * \bug mono */ |
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111 | smpl_t fvec_local_hfc(fvec_t * f); |
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112 | /** return alpha norm. |
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113 | * |
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114 | * alpha=2 means normalise variance. |
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115 | * alpha=1 means normalise abs value. |
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116 | * as alpha goes large, tends to normalisation |
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117 | * by max value. |
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118 | * |
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119 | * \bug should not use POW :( |
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120 | */ |
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121 | smpl_t fvec_alpha_norm(fvec_t * DF, smpl_t alpha); |
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122 | /** min removal */ |
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123 | void fvec_min_removal(fvec_t * mag); |
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124 | /** alpha normalisation */ |
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125 | void fvec_alpha_normalise(fvec_t * mag, uint_t alpha); |
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126 | /** add a constant to all members of a vector */ |
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127 | void fvec_add(fvec_t * mag, smpl_t threshold); |
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128 | |
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129 | /** compute adaptive threshold of input vector */ |
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130 | void fvec_adapt_thres(fvec_t * vec, fvec_t * tmp, |
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131 | uint_t win_post, uint_t win_pre); |
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132 | /** adaptative thresholding |
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133 | * |
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134 | * y=fn_thresh(fn,x,post,pre) |
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135 | * compute adaptive threshold at each time |
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136 | * fn : a function name or pointer, eg 'median' |
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137 | * x: signal vector |
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138 | * post: window length, causal part |
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139 | * pre: window length, anti-causal part |
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140 | * Returns: |
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141 | * y: signal the same length as x |
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142 | * |
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143 | * Formerly median_thresh, used compute median over a |
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144 | * window of post+pre+1 samples, but now works with any |
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145 | * function that takes a vector or matrix and returns a |
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146 | * 'representative' value for each column, eg |
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147 | * medians=fn_thresh(median,x,8,8) |
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148 | * minima=fn_thresh(min,x,8,8) |
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149 | * see SPARMS for explanation of post and pre |
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150 | */ |
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151 | smpl_t fvec_moving_thres(fvec_t * vec, fvec_t * tmp, |
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152 | uint_t win_post, uint_t win_pre, uint_t win_pos); |
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153 | |
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154 | /** returns the median of the vector |
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155 | * |
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156 | * This Quickselect routine is based on the algorithm described in |
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157 | * "Numerical recipes in C", Second Edition, |
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158 | * Cambridge University Press, 1992, Section 8.5, ISBN 0-521-43108-5 |
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159 | * |
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160 | * This code by Nicolas Devillard - 1998. Public domain, |
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161 | * available at http://ndevilla.free.fr/median/median/ |
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162 | */ |
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163 | smpl_t fvec_median(fvec_t * input); |
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164 | |
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165 | /** finds exact peak index by quadratic interpolation*/ |
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166 | smpl_t fvec_quadint(fvec_t * x, uint_t pos, uint_t span); |
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167 | |
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168 | /** Quadratic interpolation using Lagrange polynomial. |
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169 | * |
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170 | * inspired from ``Comparison of interpolation algorithms in real-time sound |
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171 | * processing'', Vladimir Arnost, |
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172 | * |
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173 | * estimate = s0 + (pf/2.)*((pf-3.)*s0-2.*(pf-2.)*s1+(pf-1.)*s2); |
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174 | * where |
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175 | * \param s0,s1,s2 are 3 known points on the curve, |
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176 | * \param pf is the floating point index [0;2] |
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177 | */ |
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178 | smpl_t aubio_quadfrac(smpl_t s0, smpl_t s1, smpl_t s2, smpl_t pf); |
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179 | |
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180 | /** returns 1 if X1 is a peak and positive */ |
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181 | uint_t fvec_peakpick(fvec_t * input, uint_t pos); |
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182 | |
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183 | /** convert frequency bin to midi value */ |
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184 | smpl_t aubio_bintomidi(smpl_t bin, smpl_t samplerate, smpl_t fftsize); |
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185 | /** convert midi value to frequency bin */ |
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186 | smpl_t aubio_miditobin(smpl_t midi, smpl_t samplerate, smpl_t fftsize); |
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187 | /** convert frequency bin to frequency (Hz) */ |
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188 | smpl_t aubio_bintofreq(smpl_t bin, smpl_t samplerate, smpl_t fftsize); |
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189 | /** convert frequency (Hz) to frequency bin */ |
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190 | smpl_t aubio_freqtobin(smpl_t freq, smpl_t samplerate, smpl_t fftsize); |
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191 | /** convert frequency (Hz) to midi value (0-128) */ |
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192 | smpl_t aubio_freqtomidi(smpl_t freq); |
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193 | /** convert midi value (0-128) to frequency (Hz) */ |
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194 | smpl_t aubio_miditofreq(smpl_t midi); |
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195 | |
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196 | /** check if current buffer level is under a given threshold */ |
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197 | uint_t aubio_silence_detection(fvec_t * ibuf, smpl_t threshold); |
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198 | /** get the current buffer level */ |
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199 | smpl_t aubio_level_detection(fvec_t * ibuf, smpl_t threshold); |
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200 | /** |
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201 | * calculate normalised autocorrelation function |
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202 | */ |
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203 | void aubio_autocorr(fvec_t * input, fvec_t * output); |
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204 | /** |
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205 | * zero-crossing rate (number of zero cross per sample) |
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206 | */ |
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207 | smpl_t aubio_zero_crossing_rate(fvec_t * input); |
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208 | /** |
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209 | * clean up cached memory at the end of program |
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210 | * |
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211 | * use this function at the end of programs to purge all |
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212 | * cached memory. so far this function is only used to clean |
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213 | * fftw cache. |
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214 | */ |
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215 | void aubio_cleanup(void); |
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216 | |
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217 | #ifdef __cplusplus |
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218 | } |
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219 | #endif |
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220 | |
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221 | #endif |
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222 | |
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