1 | /* |
---|
2 | Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org> |
---|
3 | |
---|
4 | This file is part of aubio. |
---|
5 | |
---|
6 | aubio is free software: you can redistribute it and/or modify |
---|
7 | it under the terms of the GNU General Public License as published by |
---|
8 | the Free Software Foundation, either version 3 of the License, or |
---|
9 | (at your option) any later version. |
---|
10 | |
---|
11 | aubio is distributed in the hope that it will be useful, |
---|
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
14 | GNU General Public License for more details. |
---|
15 | |
---|
16 | You should have received a copy of the GNU General Public License |
---|
17 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
---|
18 | |
---|
19 | */ |
---|
20 | |
---|
21 | /** @file |
---|
22 | * various math functions |
---|
23 | * |
---|
24 | * \todo multichannel (each function should return -or set- an array sized to |
---|
25 | * the number of channel in the input vector) |
---|
26 | * |
---|
27 | * \todo appropriate switches depending on types.h content |
---|
28 | */ |
---|
29 | |
---|
30 | #ifndef MATHUTILS_H |
---|
31 | #define MATHUTILS_H |
---|
32 | |
---|
33 | #ifdef __cplusplus |
---|
34 | extern "C" { |
---|
35 | #endif |
---|
36 | |
---|
37 | /** Window types |
---|
38 | * |
---|
39 | * inspired from |
---|
40 | * |
---|
41 | * - dafx : http://profs.sci.univr.it/%7Edafx/Final-Papers/ps/Bernardini.ps.gz |
---|
42 | * - freqtweak : http://freqtweak.sf.net/ |
---|
43 | * - extace : http://extace.sf.net/ |
---|
44 | */ |
---|
45 | typedef enum { |
---|
46 | aubio_win_rectangle, |
---|
47 | aubio_win_hamming, |
---|
48 | aubio_win_hanning, |
---|
49 | aubio_win_hanningz, |
---|
50 | aubio_win_blackman, |
---|
51 | aubio_win_blackman_harris, |
---|
52 | aubio_win_gaussian, |
---|
53 | aubio_win_welch, |
---|
54 | aubio_win_parzen |
---|
55 | } aubio_window_type; |
---|
56 | |
---|
57 | /** create window */ |
---|
58 | fvec_t * new_aubio_window(uint_t size, aubio_window_type wintype); |
---|
59 | |
---|
60 | /** principal argument |
---|
61 | * |
---|
62 | * mod(phase+PI,-TWO_PI)+PI |
---|
63 | */ |
---|
64 | smpl_t aubio_unwrap2pi (smpl_t phase); |
---|
65 | |
---|
66 | /** calculates the mean of a vector |
---|
67 | * |
---|
68 | * \bug mono |
---|
69 | */ |
---|
70 | smpl_t vec_mean(fvec_t *s); |
---|
71 | /** returns the max of a vector |
---|
72 | * |
---|
73 | * \bug mono |
---|
74 | */ |
---|
75 | smpl_t vec_max(fvec_t *s); |
---|
76 | /** returns the min of a vector |
---|
77 | * |
---|
78 | * \bug mono |
---|
79 | */ |
---|
80 | smpl_t vec_min(fvec_t *s); |
---|
81 | /** returns the index of the min of a vector |
---|
82 | * |
---|
83 | * \bug mono |
---|
84 | */ |
---|
85 | uint_t vec_min_elem(fvec_t *s); |
---|
86 | /** returns the index of the max of a vector |
---|
87 | * |
---|
88 | * \bug mono |
---|
89 | */ |
---|
90 | uint_t vec_max_elem(fvec_t *s); |
---|
91 | /** implement 'fftshift' like function |
---|
92 | * |
---|
93 | * a[0]...,a[n/2],a[n/2+1],...a[n] |
---|
94 | * |
---|
95 | * becomes |
---|
96 | * |
---|
97 | * a[n/2+1],...a[n],a[0]...,a[n/2] |
---|
98 | */ |
---|
99 | void vec_shift(fvec_t *s); |
---|
100 | /** returns sum */ |
---|
101 | smpl_t vec_sum(fvec_t *s); |
---|
102 | |
---|
103 | /** returns energy |
---|
104 | * |
---|
105 | * \bug mono |
---|
106 | */ |
---|
107 | smpl_t vec_local_energy(fvec_t * f); |
---|
108 | /** returns High Frequency Energy Content |
---|
109 | * |
---|
110 | * \bug mono */ |
---|
111 | smpl_t vec_local_hfc(fvec_t * f); |
---|
112 | /** return alpha norm. |
---|
113 | * |
---|
114 | * alpha=2 means normalise variance. |
---|
115 | * alpha=1 means normalise abs value. |
---|
116 | * as alpha goes large, tends to normalisation |
---|
117 | * by max value. |
---|
118 | * |
---|
119 | * \bug should not use POW :( |
---|
120 | */ |
---|
121 | smpl_t vec_alpha_norm(fvec_t * DF, smpl_t alpha); |
---|
122 | /** dc(min) removal */ |
---|
123 | void vec_dc_removal(fvec_t * mag); |
---|
124 | /** alpha normalisation */ |
---|
125 | void vec_alpha_normalise(fvec_t * mag, uint_t alpha); |
---|
126 | /** add a constant to all members of a vector */ |
---|
127 | void vec_add(fvec_t * mag, smpl_t threshold); |
---|
128 | |
---|
129 | /** compute adaptive threshold of input vector */ |
---|
130 | void vec_adapt_thres(fvec_t * vec, fvec_t * tmp, |
---|
131 | uint_t win_post, uint_t win_pre); |
---|
132 | /** adaptative thresholding |
---|
133 | * |
---|
134 | * y=fn_thresh(fn,x,post,pre) |
---|
135 | * compute adaptive threshold at each time |
---|
136 | * fn : a function name or pointer, eg 'median' |
---|
137 | * x: signal vector |
---|
138 | * post: window length, causal part |
---|
139 | * pre: window length, anti-causal part |
---|
140 | * Returns: |
---|
141 | * y: signal the same length as x |
---|
142 | * |
---|
143 | * Formerly median_thresh, used compute median over a |
---|
144 | * window of post+pre+1 samples, but now works with any |
---|
145 | * function that takes a vector or matrix and returns a |
---|
146 | * 'representative' value for each column, eg |
---|
147 | * medians=fn_thresh(median,x,8,8) |
---|
148 | * minima=fn_thresh(min,x,8,8) |
---|
149 | * see SPARMS for explanation of post and pre |
---|
150 | */ |
---|
151 | smpl_t vec_moving_thres(fvec_t * vec, fvec_t * tmp, |
---|
152 | uint_t win_post, uint_t win_pre, uint_t win_pos); |
---|
153 | |
---|
154 | /** returns the median of the vector |
---|
155 | * |
---|
156 | * This Quickselect routine is based on the algorithm described in |
---|
157 | * "Numerical recipes in C", Second Edition, |
---|
158 | * Cambridge University Press, 1992, Section 8.5, ISBN 0-521-43108-5 |
---|
159 | * |
---|
160 | * This code by Nicolas Devillard - 1998. Public domain, |
---|
161 | * available at http://ndevilla.free.fr/median/median/ |
---|
162 | */ |
---|
163 | smpl_t vec_median(fvec_t * input); |
---|
164 | |
---|
165 | /** finds exact peak index by quadratic interpolation*/ |
---|
166 | smpl_t vec_quadint(fvec_t * x, uint_t pos, uint_t span); |
---|
167 | |
---|
168 | /** Quadratic interpolation using Lagrange polynomial. |
---|
169 | * |
---|
170 | * inspired from ``Comparison of interpolation algorithms in real-time sound |
---|
171 | * processing'', Vladimir Arnost, |
---|
172 | * |
---|
173 | * estimate = s0 + (pf/2.)*((pf-3.)*s0-2.*(pf-2.)*s1+(pf-1.)*s2); |
---|
174 | * where |
---|
175 | * \param s0,s1,s2 are 3 known points on the curve, |
---|
176 | * \param pf is the floating point index [0;2] |
---|
177 | */ |
---|
178 | smpl_t aubio_quadfrac(smpl_t s0, smpl_t s1, smpl_t s2, smpl_t pf); |
---|
179 | |
---|
180 | /** returns 1 if X1 is a peak and positive */ |
---|
181 | uint_t vec_peakpick(fvec_t * input, uint_t pos); |
---|
182 | |
---|
183 | /** convert frequency bin to midi value */ |
---|
184 | smpl_t aubio_bintomidi(smpl_t bin, smpl_t samplerate, smpl_t fftsize); |
---|
185 | /** convert midi value to frequency bin */ |
---|
186 | smpl_t aubio_miditobin(smpl_t midi, smpl_t samplerate, smpl_t fftsize); |
---|
187 | /** convert frequency bin to frequency (Hz) */ |
---|
188 | smpl_t aubio_bintofreq(smpl_t bin, smpl_t samplerate, smpl_t fftsize); |
---|
189 | /** convert frequency (Hz) to frequency bin */ |
---|
190 | smpl_t aubio_freqtobin(smpl_t freq, smpl_t samplerate, smpl_t fftsize); |
---|
191 | /** convert frequency (Hz) to midi value (0-128) */ |
---|
192 | smpl_t aubio_freqtomidi(smpl_t freq); |
---|
193 | /** convert midi value (0-128) to frequency (Hz) */ |
---|
194 | smpl_t aubio_miditofreq(smpl_t midi); |
---|
195 | |
---|
196 | /** check if current buffer level is under a given threshold */ |
---|
197 | uint_t aubio_silence_detection(fvec_t * ibuf, smpl_t threshold); |
---|
198 | /** get the current buffer level */ |
---|
199 | smpl_t aubio_level_detection(fvec_t * ibuf, smpl_t threshold); |
---|
200 | /** |
---|
201 | * calculate normalised autocorrelation function |
---|
202 | */ |
---|
203 | void aubio_autocorr(fvec_t * input, fvec_t * output); |
---|
204 | /** |
---|
205 | * zero-crossing rate (number of zero cross per sample) |
---|
206 | */ |
---|
207 | smpl_t aubio_zero_crossing_rate(fvec_t * input); |
---|
208 | /** |
---|
209 | * clean up cached memory at the end of program |
---|
210 | * |
---|
211 | * use this function at the end of programs to purge all |
---|
212 | * cached memory. so far this function is only used to clean |
---|
213 | * fftw cache. |
---|
214 | */ |
---|
215 | void aubio_cleanup(void); |
---|
216 | |
---|
217 | #ifdef __cplusplus |
---|
218 | } |
---|
219 | #endif |
---|
220 | |
---|
221 | #endif |
---|
222 | |
---|