2 Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
4 This file is part of aubio.
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.
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.
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/>.
30 Pitch detection object
32 This file creates the objects required for the computation of the selected
33 pitch detection algorithm and output the results, in midi note or Hz.
35 \section pitch Pitch detection methods
37 A list of the pitch detection methods currently available follows.
39 \b \p default : use the default method
41 Currently, the default method is set to \p yinfft .
43 \b \p schmitt : Schmitt trigger
45 This pitch extraction method implements a Schmitt trigger to estimate the
48 This file was derived from the tuneit project, written by Mario Lang to
49 detect the fundamental frequency of a sound.
51 See http://delysid.org/tuneit.html
53 \b \p fcomb : a fast harmonic comb filter
55 This pitch extraction method implements a fast harmonic comb filter to
56 determine the fundamental frequency of a harmonic sound.
58 This file was derived from the tuneit project, written by Mario Lang to
59 detect the fundamental frequency of a sound.
61 See http://delysid.org/tuneit.html
63 \b \p mcomb : multiple-comb filter
65 This fundamental frequency estimation algorithm implements spectral
66 flattening, multi-comb filtering and peak histogramming.
68 This method was designed by Juan P. Bello and described in:
70 Juan-Pablo Bello. ``Towards the Automated Analysis of Simple Polyphonic
71 Music''. PhD thesis, Centre for Digital Music, Queen Mary University of
72 London, London, UK, 2003.
74 \b \p yin : YIN algorithm
76 This algorithm was developed by A. de Cheveigne and H. Kawahara and
79 De Cheveigné, A., Kawahara, H. (2002) "YIN, a fundamental frequency
80 estimator for speech and music", J. Acoust. Soc. Am. 111, 1917-1930.
82 see http://recherche.ircam.fr/equipes/pcm/pub/people/cheveign.html
84 \b \p yinfast: Yinfast algorithm
86 This algorithm is equivalent to the YIN algorithm, but computed in the
87 spectral domain for efficiency. See also `python/demos/demo_yin_compare.py`.
89 \b \p yinfft : Yinfft algorithm
91 This algorithm was derived from the YIN algorithm. In this implementation, a
92 Fourier transform is used to compute a tapered square difference function,
93 which allows spectral weighting. Because the difference function is tapered,
94 the selection of the period is simplified.
96 Paul Brossier, [Automatic annotation of musical audio for interactive
97 systems](http://aubio.org/phd/), Chapter 3, Pitch Analysis, PhD thesis,
98 Centre for Digital music, Queen Mary University of London, London, UK, 2006.
100 \example pitch/test-pitch.c
101 \example examples/aubiopitch.c
105 /** pitch detection object */
106 typedef struct _aubio_pitch_t aubio_pitch_t;
108 /** execute pitch detection on an input signal frame
110 \param o pitch detection object as returned by new_aubio_pitch()
111 \param in input signal of size [hop_size]
112 \param out output pitch candidates of size [1]
115 void aubio_pitch_do (aubio_pitch_t * o, const fvec_t * in, fvec_t * out);
117 /** change yin or yinfft tolerance threshold
119 \param o pitch detection object as returned by new_aubio_pitch()
120 \param tol tolerance default is 0.15 for yin and 0.85 for yinfft
123 uint_t aubio_pitch_set_tolerance (aubio_pitch_t * o, smpl_t tol);
125 /** get yin or yinfft tolerance threshold
127 \param o pitch detection object as returned by new_aubio_pitch()
128 \return tolerance (default is 0.15 for yin and 0.85 for yinfft)
131 smpl_t aubio_pitch_get_tolerance (aubio_pitch_t * o);
133 /** deletion of the pitch detection object
135 \param o pitch detection object as returned by new_aubio_pitch()
138 void del_aubio_pitch (aubio_pitch_t * o);
140 /** creation of the pitch detection object
142 \param method set pitch detection algorithm
143 \param buf_size size of the input buffer to analyse
144 \param hop_size step size between two consecutive analysis instant
145 \param samplerate sampling rate of the signal
147 \return newly created ::aubio_pitch_t
150 aubio_pitch_t *new_aubio_pitch (const char_t * method,
151 uint_t buf_size, uint_t hop_size, uint_t samplerate);
153 /** set the output unit of the pitch detection object
155 \param o pitch detection object as returned by new_aubio_pitch()
156 \param mode set pitch units for output
158 mode can be one of "Hz", "midi", "cent", or "bin". Defaults to "Hz".
160 \return 0 if successfull, non-zero otherwise
163 uint_t aubio_pitch_set_unit (aubio_pitch_t * o, const char_t * mode);
165 /** set the silence threshold of the pitch detection object
167 \param o pitch detection object as returned by new_aubio_pitch()
168 \param silence level threshold under which pitch should be ignored, in dB
170 \return 0 if successfull, non-zero otherwise
173 uint_t aubio_pitch_set_silence (aubio_pitch_t * o, smpl_t silence);
175 /** set the silence threshold of the pitch detection object
177 \param o pitch detection object as returned by ::new_aubio_pitch()
179 \return level threshold under which pitch should be ignored, in dB
182 smpl_t aubio_pitch_get_silence (aubio_pitch_t * o);
184 /** get the current confidence
186 \param o pitch detection object as returned by new_aubio_pitch()
188 \return the current confidence of the pitch algorithm
191 smpl_t aubio_pitch_get_confidence (aubio_pitch_t * o);
197 #endif /* AUBIO_PITCH_H */