1 /* -*- c++ -*- */
2 /*
3 * Copyright 2005,2010,2013 Free Software Foundation, Inc.
4 *
5 * This file is part of GNU Radio
6 *
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)
10 * any later version.
11 *
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.
16 *
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.
21 */
22
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include "rms_ff_impl.h"
28 #include <gnuradio/io_signature.h>
29 #include <cmath>
30
31 namespace gr {
32 namespace blocks {
33
make(double alpha)34 rms_ff::sptr rms_ff::make(double alpha)
35 {
36 return gnuradio::get_initial_sptr(new rms_ff_impl(alpha));
37 }
38
rms_ff_impl(double alpha)39 rms_ff_impl::rms_ff_impl(double alpha)
40 : sync_block("rms_ff",
41 io_signature::make(1, 1, sizeof(float)),
42 io_signature::make(1, 1, sizeof(float)))
43 {
44 set_alpha(alpha);
45 }
46
~rms_ff_impl()47 rms_ff_impl::~rms_ff_impl() {}
48
set_alpha(double alpha)49 void rms_ff_impl::set_alpha(double alpha)
50 {
51 d_alpha = alpha;
52 d_beta = 1 - d_alpha;
53 d_avg = 0;
54 }
55
work(int noutput_items,gr_vector_const_void_star & input_items,gr_vector_void_star & output_items)56 int rms_ff_impl::work(int noutput_items,
57 gr_vector_const_void_star& input_items,
58 gr_vector_void_star& output_items)
59 {
60 const float* in = (const float*)input_items[0];
61 float* out = (float*)output_items[0];
62
63 for (int i = 0; i < noutput_items; i++) {
64 double mag_sqrd = in[i] * in[i];
65 d_avg = d_beta * d_avg + d_alpha * mag_sqrd;
66 out[i] = sqrt(d_avg);
67 }
68
69 return noutput_items;
70 }
71
72 } /* namespace blocks */
73 } /* namespace gr */
74