[88199ce] | 1 | /* |
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[b235c0e] | 2 | Copyright (C) 2007-2013 Paul Brossier <piem@aubio.org> |
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[1c2e186] | 3 | and Amaury Hazan <ahazan@iua.upf.edu> |
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[88199ce] | 4 | |
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[1c2e186] | 5 | This file is part of aubio. |
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[e03f74d] | 6 | |
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[1c2e186] | 7 | aubio is free software: you can redistribute it and/or modify |
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| 8 | it under the terms of the GNU General Public License as published by |
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| 9 | the Free Software Foundation, either version 3 of the License, or |
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| 10 | (at your option) any later version. |
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[88199ce] | 11 | |
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[1c2e186] | 12 | aubio is distributed in the hope that it will be useful, |
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| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 15 | GNU General Public License for more details. |
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[88199ce] | 16 | |
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[1c2e186] | 17 | You should have received a copy of the GNU General Public License |
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| 18 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
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[88199ce] | 19 | |
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[73eaa2e] | 20 | */ |
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| 21 | |
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[d99d819] | 22 | /** \file |
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| 23 | |
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[aba718a] | 24 | Mel-Frequency Cepstrum Coefficients object |
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| 25 | |
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| 26 | This object computes MFCC coefficients on an input cvec_t. |
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| 27 | |
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| 28 | The implementation follows the specifications established by Malcolm Slaney |
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[dec8b9d] | 29 | in its Auditory Toolbox, available online at the following address (see |
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| 30 | file mfcc.m): |
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[aba718a] | 31 | |
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[dec8b9d] | 32 | https://engineering.purdue.edu/~malcolm/interval/1998-010/ |
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[d99d819] | 33 | |
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[8a5c8ba] | 34 | \example spectral/test-mfcc.c |
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[b8c0685] | 35 | |
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[d99d819] | 36 | */ |
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| 37 | |
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[6f42c16] | 38 | #ifndef AUBIO_MFCC_H |
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| 39 | #define AUBIO_MFCC_H |
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[88199ce] | 40 | |
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[7c6c806] | 41 | #ifdef __cplusplus |
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[e03f74d] | 42 | extern "C" |
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| 43 | { |
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[7c6c806] | 44 | #endif |
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| 45 | |
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[d99d819] | 46 | /** mfcc object */ |
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| 47 | typedef struct _aubio_mfcc_t aubio_mfcc_t; |
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[88199ce] | 48 | |
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[8708556] | 49 | /** create mfcc object |
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[88199ce] | 50 | |
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[3ac7cb0] | 51 | \param buf_size size of analysis buffer (and length the FFT transform) |
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[e03f74d] | 52 | \param samplerate audio sampling rate |
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[c9cebe1] | 53 | \param n_coeffs number of desired coefficients |
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[d99d819] | 54 | \param n_filters number of desired filters |
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[7c6c806] | 55 | |
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[8708556] | 56 | */ |
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[3ac7cb0] | 57 | aubio_mfcc_t *new_aubio_mfcc (uint_t buf_size, |
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[6107f4c] | 58 | uint_t n_filters, uint_t n_coeffs, uint_t samplerate); |
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[e03f74d] | 59 | |
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[8708556] | 60 | /** delete mfcc object |
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| 61 | |
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| 62 | \param mf mfcc object as returned by new_aubio_mfcc |
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| 63 | |
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| 64 | */ |
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[e03f74d] | 65 | void del_aubio_mfcc (aubio_mfcc_t * mf); |
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| 66 | |
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[8708556] | 67 | /** mfcc object processing |
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| 68 | |
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| 69 | \param mf mfcc object as returned by new_aubio_mfcc |
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[3ac7cb0] | 70 | \param in input spectrum (buf_size long) |
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[e03f74d] | 71 | \param out output mel coefficients buffer (n_coeffs long) |
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[8708556] | 72 | |
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| 73 | */ |
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[feb694b] | 74 | void aubio_mfcc_do (aubio_mfcc_t * mf, const cvec_t * in, fvec_t * out); |
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[8708556] | 75 | |
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[10fafc2] | 76 | /** set power parameter |
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| 77 | |
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| 78 | \param mf mfcc object, as returned by new_aubio_mfcc() |
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| 79 | \param power Raise norm of the input spectrum norm to this power before |
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| 80 | computing filterbank. Defaults to `1`. |
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| 81 | |
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| 82 | See aubio_filterbank_set_power(). |
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| 83 | |
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| 84 | */ |
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[517630f] | 85 | uint_t aubio_mfcc_set_power (aubio_mfcc_t *mf, smpl_t power); |
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[10fafc2] | 86 | |
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| 87 | /** get power parameter |
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| 88 | |
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| 89 | \param mf mfcc object, as returned by new_aubio_mfcc() |
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| 90 | \return current power parameter. Defaults to `1`. |
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| 91 | |
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| 92 | See aubio_filterbank_get_power(). |
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| 93 | |
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| 94 | */ |
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[517630f] | 95 | uint_t aubio_mfcc_get_power (aubio_mfcc_t *mf); |
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| 96 | |
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[11c899b] | 97 | /** set scaling parameter |
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| 98 | |
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| 99 | \param mf mfcc object, as returned by new_aubio_mfcc() |
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| 100 | \param scale Scaling value to apply. |
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| 101 | |
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| 102 | Scales the output of the filterbank after taking its logarithm and before |
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| 103 | computing the DCT. Defaults to `1`. |
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| 104 | |
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| 105 | */ |
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[10fafc2] | 106 | uint_t aubio_mfcc_set_scale (aubio_mfcc_t *mf, smpl_t scale); |
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[11c899b] | 107 | |
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| 108 | /** get scaling parameter |
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| 109 | |
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| 110 | \param mf mfcc object, as returned by new_aubio_mfcc() |
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| 111 | \return current scaling parameter. Defaults to `1`. |
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| 112 | |
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| 113 | */ |
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[10fafc2] | 114 | uint_t aubio_mfcc_get_scale (aubio_mfcc_t *mf); |
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| 115 | |
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| 116 | /** Mel filterbank initialization |
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| 117 | |
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| 118 | \param mf mfcc object |
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| 119 | \param fmin start frequency, in Hz |
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| 120 | \param fmax end frequency, in Hz |
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| 121 | |
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| 122 | The filterbank will be initialized with bands linearly spaced in the mel |
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| 123 | scale, from `fmin` to `fmax`. |
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| 124 | |
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| 125 | See also |
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| 126 | -------- |
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| 127 | |
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| 128 | aubio_filterbank_set_mel_coeffs() |
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| 129 | |
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| 130 | */ |
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| 131 | uint_t aubio_mfcc_set_mel_coeffs (aubio_mfcc_t *mf, |
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| 132 | smpl_t fmin, smpl_t fmax); |
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| 133 | |
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| 134 | /** Mel filterbank initialization |
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| 135 | |
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| 136 | \param mf mfcc object |
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| 137 | \param fmin start frequency, in Hz |
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| 138 | \param fmax end frequency, in Hz |
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| 139 | |
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| 140 | The bank of filters will be initalized to to cover linearly spaced bands in |
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| 141 | the Htk mel scale, from `fmin` to `fmax`. |
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| 142 | |
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| 143 | See also |
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| 144 | -------- |
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| 145 | |
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| 146 | aubio_filterbank_set_mel_coeffs_htk() |
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| 147 | |
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| 148 | */ |
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| 149 | uint_t aubio_mfcc_set_mel_coeffs_htk (aubio_mfcc_t *mf, |
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| 150 | smpl_t fmin, smpl_t fmax); |
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| 151 | |
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| 152 | /** Mel filterbank initialization (Auditory Toolbox's parameters) |
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| 153 | |
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| 154 | \param mf mfcc object |
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| 155 | \param samplerate audio sampling rate, in Hz |
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| 156 | |
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| 157 | The filter coefficients are built to match exactly Malcolm Slaney's Auditory |
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| 158 | Toolbox implementation. The number of filters should be 40. |
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| 159 | |
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| 160 | This is the default filterbank when `mf` was created with `n_filters = 40`. |
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| 161 | |
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| 162 | See also |
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| 163 | -------- |
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| 164 | |
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| 165 | aubio_filterbank_set_mel_coeffs_slaney() |
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| 166 | |
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| 167 | */ |
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[c879811] | 168 | uint_t aubio_mfcc_set_mel_coeffs_slaney (aubio_mfcc_t *mf); |
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[517630f] | 169 | |
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[7c6c806] | 170 | #ifdef __cplusplus |
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| 171 | } |
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| 172 | #endif |
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[88199ce] | 173 | |
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[6f42c16] | 174 | #endif /* AUBIO_MFCC_H */ |
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