3 * Copyright 2005,2010 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
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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)
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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
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19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
26 #include <gr_simple_squelch_cc.h>
27 #include <gr_io_signature.h>
30 gr_simple_squelch_cc_sptr
31 gr_make_simple_squelch_cc(double threshold_db, double alpha)
33 return gnuradio::get_initial_sptr(new gr_simple_squelch_cc(threshold_db, alpha));
36 gr_simple_squelch_cc::gr_simple_squelch_cc (double threshold_db, double alpha)
37 : gr_sync_block ("simple_squelch_cc",
38 gr_make_io_signature(1, 1, sizeof(gr_complex)),
39 gr_make_io_signature(1, 1, sizeof(gr_complex))),
40 d_iir(alpha), d_unmuted(false)
42 set_threshold (threshold_db);
45 gr_simple_squelch_cc::~gr_simple_squelch_cc()
51 gr_simple_squelch_cc::work(int noutput_items,
52 gr_vector_const_void_star &input_items,
53 gr_vector_void_star &output_items)
55 const gr_complex *in = (const gr_complex *) input_items[0];
56 gr_complex *out = (gr_complex *) output_items[0];
58 for (int i = 0; i < noutput_items; i++){
59 double mag_sqrd = in[i].real()*in[i].real() + in[i].imag()*in[i].imag();
60 double f = d_iir.filter(mag_sqrd);
67 d_unmuted = d_iir.prev_output() >= d_threshold;
72 gr_simple_squelch_cc::set_threshold(double decibels)
74 // convert to absolute threshold (mag squared)
75 d_threshold = std::pow(10.0, decibels/10);
79 gr_simple_squelch_cc::threshold() const
81 return 10 * log10(d_threshold);
85 gr_simple_squelch_cc::set_alpha(double alpha)
87 d_iir.set_taps(alpha);
91 gr_simple_squelch_cc::squelch_range() const
93 std::vector<float> r(3);
94 r[0] = -50.0; // min FIXME
95 r[1] = +50.0; // max FIXME
96 r[2] = (r[1] - r[0]) / 100; // step size