3 * Copyright 2007 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
27 #include <gr_peak_detector2_fb.h>
28 #include <gr_io_signature.h>
31 gr_peak_detector2_fb_sptr
32 gr_make_peak_detector2_fb (float threshold_factor_rise,
33 int look_ahead, float alpha)
35 return gr_peak_detector2_fb_sptr (new gr_peak_detector2_fb (threshold_factor_rise,
39 gr_peak_detector2_fb::gr_peak_detector2_fb (float threshold_factor_rise,
40 int look_ahead, float alpha)
41 : gr_sync_block ("peak_detector2_fb",
42 gr_make_io_signature (1, 1, sizeof(float)),
43 gr_make_io_signature2 (1, 2, sizeof(char), sizeof(float))),
44 d_threshold_factor_rise(threshold_factor_rise),
45 d_look_ahead(look_ahead), d_alpha(alpha), d_avg(0.0f), d_found(false)
50 gr_peak_detector2_fb::work (int noutput_items,
51 gr_vector_const_void_star &input_items,
52 gr_vector_void_star &output_items) {
53 float *iptr = (float *) input_items[0];
54 char *optr = (char *) output_items[0];
56 assert(noutput_items >= 2);
58 memset(optr, 0, noutput_items*sizeof(char));
60 for (int i = 0; i < noutput_items; i++) {
63 // Have not yet detected presence of peak
64 if (iptr[i] > d_avg * (1.0f + d_threshold_factor_rise)) {
66 d_look_ahead_remaining = d_look_ahead;
67 d_peak_val = -(float)INFINITY;
70 d_avg = d_alpha*iptr[i] + (1.0f - d_alpha)*d_avg;
74 // Detected presence of peak
75 if (iptr[i] > d_peak_val) {
79 else if (d_look_ahead_remaining <= 0) {
85 // Have not yet located peak, loop and keep searching.
86 d_look_ahead_remaining--;
89 // Every iteration of the loop, write debugging signal out if
91 if (output_items.size() == 2) {
92 float *sigout = (float *) output_items[1];
100 // else if detected presence, keep searching during the next call to work.
101 int tmp = d_peak_ind;