1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
/* -*- c++ -*- */
/* This is a version of the GNU Radio peak_detector_fb block before commit 9d9ea63c45b5f314eb344a69340ef49e8edafdfa.
*
* Copyright 2007,2010,2013 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gnuradio/io_signature.h>
#include "peak_detector_fb_impl.h"
#include <string.h>
namespace gr {
namespace dab {
peak_detector_fb::sptr
peak_detector_fb::make(float threshold_factor_rise, float threshold_factor_fall, int look_ahead, float alpha)
{
return gnuradio::get_initial_sptr
(new peak_detector_fb_impl(threshold_factor_rise, threshold_factor_fall, look_ahead, alpha));
}
/*
* The private constructor
*/
peak_detector_fb_impl::peak_detector_fb_impl(float threshold_factor_rise, float threshold_factor_fall, int look_ahead, float alpha)
: gr::sync_block("peak_detector_fb",
gr::io_signature::make(1, 1, sizeof(float)),
gr::io_signature::make(1, 1, sizeof(char))),
d_threshold_factor_rise(threshold_factor_rise),
d_threshold_factor_fall(threshold_factor_fall),
d_look_ahead(look_ahead), d_avg_alpha(alpha), d_avg(0), d_found(0)
{
d_state = 0;
d_peak_val = -(float)INFINITY;
}
/*
* Our virtual destructor.
*/
peak_detector_fb_impl::~peak_detector_fb_impl()
{
}
int
peak_detector_fb_impl::work(int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
float *iptr = (float*)input_items[0];
char *optr = (char*)output_items[0];
int peak_ind = 0;
int i = 0;
//printf("noutput_items %d\n",noutput_items);
while(i < noutput_items) {
optr[i] = 0;
if(d_state == 0) { // below threshold
if(iptr[i] > d_avg*d_threshold_factor_rise) {
d_state = 1;
}
else {
d_avg = (d_avg_alpha)*iptr[i] + (1-d_avg_alpha)*d_avg;
i++;
}
}
else if(d_state == 1) { // above threshold, have not found peak
if(iptr[i] > d_peak_val) {
d_peak_val = iptr[i];
peak_ind = i;
d_avg = (d_avg_alpha)*iptr[i] + (1-d_avg_alpha)*d_avg;
i++;
}
else if(iptr[i] > d_avg*d_threshold_factor_fall) {
d_avg = (d_avg_alpha)*iptr[i] + (1-d_avg_alpha)*d_avg;
i++;
}
else {
optr[peak_ind] = 1;
d_state = 0;
d_peak_val = -(float)INFINITY;
//printf("Leaving State 1: Peak: %f Peak Ind: %d i: %d noutput_items: %d\n",
//peak_val, peak_ind, i, noutput_items);
}
}
}
if(d_state == 0) {
//printf("Leave in State 0, produced %d\n",noutput_items);
return noutput_items;
}
else { // only return up to passing the threshold
//printf("Leave in State 1, only produced %d of %d\n",peak_ind,noutput_items);
return peak_ind ;
}
}
} /* namespace dab */
} /* namespace gr */
|
