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Diffstat (limited to 'flib/src/peak~.c')
| -rw-r--r-- | flib/src/peak~.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/flib/src/peak~.c b/flib/src/peak~.c new file mode 100644 index 0000000..fdc1e6a --- /dev/null +++ b/flib/src/peak~.c @@ -0,0 +1,129 @@ +/* flib - PD library for feature extraction +Copyright (C) 2005 Jamie Bullock + +This program 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 2 +of the License, or (at your option) any later version. + +This program 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 this program; if not, write to the Free Software +Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +*/ + + + +/*Outputs amplitude (in dB referenecd to a maximum of 100dB) and frequency of spectral peaks from outlets 1 and 2. A peak is defined as a bin that has a greater magnitude than either of its neighbouring bins. A peak detection threshold is given by the first argument (or right inlet as a float) as a percentage of the frame maximum, i.e. a setting of 100 finds peaks equal to the size of the highest peak, a setting of 0 will output all peaks. Default is 0*/ + +#include "flib.h" +#define SQ(a) (a * a) + +static t_class *peak_class; + +typedef struct _peak { + t_object x_obj; + t_float f, thresh, *buf; + t_int sr,M; +} t_peak; + +static t_float max(t_float *array, t_int size){ + register t_float t = array[0]; + register t_int i; + for(i = 1; i < size; i++){ + if (t < array[i]) + t = array[i]; + } + return t; +} + +static t_int *peak_perform(t_int *w) +{ + t_sample *in1 = (t_sample *)(w[1]); + t_sample *out1 = (t_float *)(w[2]); + t_sample *out2 = (t_float *)(w[3]); + t_int N = (t_int)(w[4]), M = N >> 1,n; + t_float thresh = *(t_float *)(w[5]); + t_peak *x = (t_peak *)(w[6]); + t_float width = (t_float)x->sr / (t_float)N,y,y2,y3,p,t; + + x->M = M; + x->buf = getbytes(M * sizeof(t_float)); + + for(n = 0; n < M; n++){ + if ((t = in1[n] * 100000) >= 1) /* ensure we never take log10(0) */ + x->buf[n] = t; + else + x->buf[n] = 1; + } + + if(thresh < 0 || thresh > 100) + thresh = 0; + else + thresh *= .01 * max(&x->buf[0],M); + + out1[0] = 0; + out2[0] = 0; + + for(n = 1; n < M; n++){ + if(x->buf[n] >= thresh){ + if(x->buf[n] > x->buf[n - 1] && x->buf[n] > x->buf[n + 1]){ + out1[n] = width * (n + (p = .5 * (y = 20 * log10(x->buf[n-1]) - (y3 = 20 * log10(x->buf[n+1]))) / (20 * log10(x->buf[n - 1]) - 2 * (y2 = 20 * log10(x->buf[n])) + 20 * log10(x->buf[n + 1])))); + out2[n] = y2 - .25 * (y - y3) * p; + } + else{ + out1[n] = 0; + out2[n] = 0; + } + } + else{ + out1[n] = 0; + out2[n] = 0; + } + } + + for (;n < N; n++){ + out1[n] = 0; + out2[n] = 0; + } + + return (w+7); + +} + +static void peak_dsp(t_peak *x, t_signal **sp) +{ + dsp_add(peak_perform, 6, sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[0]->s_n,&x->thresh, x); +} + +static void *peak_new(t_symbol *s, t_int argc, t_atom *argv) +{ + t_peak *x = (t_peak *)pd_new(peak_class); + floatinlet_new(&x->x_obj, &x->thresh); + outlet_new(&x->x_obj, &s_signal); + outlet_new(&x->x_obj, &s_signal); + x->sr = (t_int)sys_getsr(); + x->thresh = atom_getfloatarg(0,argc, argv); + + return (void *)x; +} + +static void peak_free(t_peak *x){ + freebytes(x->buf, sizeof(t_float) * x->M); +} + +void peak_tilde_setup(void) { + peak_class = class_new(gensym("peak~"), + (t_newmethod)peak_new, + (t_method)peak_free, sizeof(t_peak), + CLASS_DEFAULT, A_GIMME, 0); + + class_addmethod(peak_class, (t_method)peak_dsp, gensym("dsp"), 0); + CLASS_MAINSIGNALIN(peak_class, t_peak,f); + class_sethelpsymbol(peak_class, gensym("help-flib")); + +} |