54 lines
1.6 KiB
C++
54 lines
1.6 KiB
C++
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/*
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* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
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*
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* This file is part of PortaPack.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#include "dsp_squelch.hpp"
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#include <cstdint>
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#include <array>
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bool FMSquelch::execute(const buffer_f32_t& audio) {
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if( threshold_squared == 0.0f ) {
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return true;
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}
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// TODO: No hard-coded array size.
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std::array<float, N> squelch_energy_buffer;
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const buffer_f32_t squelch_energy {
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squelch_energy_buffer.data(),
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squelch_energy_buffer.size()
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};
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non_audio_hpf.execute(audio, squelch_energy);
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float non_audio_max_squared = 0;
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for(const auto sample : squelch_energy_buffer) {
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const float sample_squared = sample * sample;
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if( sample_squared > non_audio_max_squared ) {
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non_audio_max_squared = sample_squared;
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}
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}
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return (non_audio_max_squared < threshold_squared);
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}
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void FMSquelch::set_threshold(const float new_value) {
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threshold_squared = new_value * new_value;
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}
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