/* * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc. * * This file is part of PortaPack. * * This program 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 2, or (at your option) * any later version. * * This program 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 this program; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #include "dsp_squelch.hpp" #include #include bool FMSquelch::execute(buffer_s16_t audio) { // TODO: No hard-coded array size. std::array squelch_energy_buffer; const buffer_s16_t squelch_energy { squelch_energy_buffer.data(), squelch_energy_buffer.size() }; non_audio_hpf.execute(audio, squelch_energy); uint32_t max_squared = 0; for(const auto sample : squelch_energy_buffer) { const uint32_t sample_squared = sample * sample; if( sample_squared > max_squared ) { max_squared = sample_squared; } } return (max_squared < threshold_squared); } void FMSquelch::set_threshold(const uint32_t new_value) { threshold_squared = new_value * new_value; }