ref: f7b7a351084295118143a25000512280b1c9e45b
dir: /src/onset/peakpicker.c/
/* Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org> This file is part of aubio. aubio is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. aubio is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with aubio. If not, see <http://www.gnu.org/licenses/>. */ #include "aubio_priv.h" #include "fvec.h" #include "mathutils.h" #include "lvec.h" #include "temporal/filter.h" #include "temporal/biquad.h" #include "onset/peakpicker.h" /** function pointer to thresholding function */ typedef smpl_t (*aubio_thresholdfn_t)(fvec_t *input); /** function pointer to peak-picking function */ typedef uint_t (*aubio_pickerfn_t)(fvec_t *input, uint_t pos); /** set peak picker thresholding function */ uint_t aubio_peakpicker_set_thresholdfn(aubio_peakpicker_t * p, aubio_thresholdfn_t thresholdfn); /** get peak picker thresholding function */ aubio_thresholdfn_t aubio_peakpicker_get_thresholdfn(aubio_peakpicker_t * p); /* peak picking parameters, default values in brackets * * [<----post----|--pre-->] * .................|............. * time-> ^now */ struct _aubio_peakpicker_t { /** thresh: offset threshold [0.033 or 0.01] */ smpl_t threshold; /** win_post: median filter window length (causal part) [8] */ uint_t win_post; /** pre: median filter window (anti-causal part) [post-1] */ uint_t win_pre; /** threshfn: name or handle of fn for computing adaptive threshold [median] */ aubio_thresholdfn_t thresholdfn; /** picker: name or handle of fn for picking event times [peakpick] */ aubio_pickerfn_t pickerfn; /** biquad lowpass filter */ aubio_filter_t *biquad; /** original onsets */ fvec_t *onset_keep; /** modified onsets */ fvec_t *onset_proc; /** peak picked window [3] */ fvec_t *onset_peek; /** thresholded function */ fvec_t *thresholded; /** scratch pad for biquad and median */ fvec_t *scratch; /** \bug should be used to calculate filter coefficients */ /* cutoff: low-pass filter cutoff [0.34, 1] */ /* smpl_t cutoff; */ /* not used anymore */ /* time precision [512/44100 winlength/samplerate, fs/buffer_size */ /* smpl_t tau; */ /* alpha: normalisation exponent [9] */ /* smpl_t alpha; */ }; /** modified version for real time, moving mean adaptive threshold this method * is slightly more permissive than the offline one, and yelds to an increase * of false positives. best */ void aubio_peakpicker_do (aubio_peakpicker_t * p, fvec_t * onset, fvec_t * out) { fvec_t *onset_keep = p->onset_keep; fvec_t *onset_proc = p->onset_proc; fvec_t *onset_peek = p->onset_peek; fvec_t *thresholded = p->thresholded; fvec_t *scratch = p->scratch; smpl_t mean = 0., median = 0.; uint_t length = p->win_post + p->win_pre + 1; uint_t j = 0; /* store onset in onset_keep */ /* shift all elements but last, then write last */ for (j = 0; j < length - 1; j++) { onset_keep->data[j] = onset_keep->data[j + 1]; onset_proc->data[j] = onset_keep->data[j]; } onset_keep->data[length - 1] = onset->data[0]; onset_proc->data[length - 1] = onset->data[0]; /* filter onset_proc */ /** \bug filtfilt calculated post+pre times, should be only once !? */ aubio_filter_do_filtfilt (p->biquad, onset_proc, scratch); /* calculate mean and median for onset_proc */ mean = fvec_mean (onset_proc); /* copy to scratch */ for (j = 0; j < length; j++) scratch->data[j] = onset_proc->data[j]; median = p->thresholdfn (scratch); /* shift peek array */ for (j = 0; j < 3 - 1; j++) onset_peek->data[j] = onset_peek->data[j + 1]; /* calculate new tresholded value */ thresholded->data[0] = onset_proc->data[p->win_post] - median - mean * p->threshold; onset_peek->data[2] = thresholded->data[0]; out->data[0] = (p->pickerfn) (onset_peek, 1); if (out->data[0]) { out->data[0] = fvec_quadratic_peak_pos (onset_peek, 1); } } /** this method returns the current value in the pick peaking buffer * after smoothing */ fvec_t * aubio_peakpicker_get_thresholded_input (aubio_peakpicker_t * p) { return p->thresholded; } uint_t aubio_peakpicker_set_threshold (aubio_peakpicker_t * p, smpl_t threshold) { p->threshold = threshold; return AUBIO_OK; } smpl_t aubio_peakpicker_get_threshold (aubio_peakpicker_t * p) { return p->threshold; } uint_t aubio_peakpicker_set_thresholdfn (aubio_peakpicker_t * p, aubio_thresholdfn_t thresholdfn) { p->thresholdfn = thresholdfn; return AUBIO_OK; } aubio_thresholdfn_t aubio_peakpicker_get_thresholdfn (aubio_peakpicker_t * p) { return (aubio_thresholdfn_t) (p->thresholdfn); } aubio_peakpicker_t * new_aubio_peakpicker (void) { aubio_peakpicker_t *t = AUBIO_NEW (aubio_peakpicker_t); t->threshold = 0.1; /* 0.0668; 0.33; 0.082; 0.033; */ t->win_post = 5; t->win_pre = 1; t->thresholdfn = (aubio_thresholdfn_t) (fvec_median); /* (fvec_mean); */ t->pickerfn = (aubio_pickerfn_t) (fvec_peakpick); t->scratch = new_fvec (t->win_post + t->win_pre + 1); t->onset_keep = new_fvec (t->win_post + t->win_pre + 1); t->onset_proc = new_fvec (t->win_post + t->win_pre + 1); t->onset_peek = new_fvec (3); t->thresholded = new_fvec (1); /* cutoff: low-pass filter with cutoff reduced frequency at 0.34 generated with octave butter function: [b,a] = butter(2, 0.34); */ t->biquad = new_aubio_filter_biquad (0.15998789, 0.31997577, 0.15998789, // FIXME: broken since c9e20ca, revert for now //-0.59488894, 0.23484048); 0.23484048, 0); return t; } void del_aubio_peakpicker (aubio_peakpicker_t * p) { del_aubio_filter (p->biquad); del_fvec (p->onset_keep); del_fvec (p->onset_proc); del_fvec (p->onset_peek); del_fvec (p->thresholded); del_fvec (p->scratch); AUBIO_FREE (p); }