portapack-mayhem/firmware/baseband/dsp_squelch.hpp
2015-08-27 09:59:03 -07:00

46 lines
1.3 KiB
C++

/*
* 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.
*/
#ifndef __DSP_SQUELCH_H__
#define __DSP_SQUELCH_H__
#include "buffer.hpp"
#include "dsp_iir.hpp"
#include "dsp_iir_config.hpp"
#include <cstdint>
#include <cstddef>
class FMSquelch {
public:
bool execute(buffer_s16_t audio);
private:
static constexpr size_t N = 32;
static constexpr int16_t threshold = 3072;
// nyquist = 48000 / 2.0
// scipy.signal.iirdesign(wp=8000 / nyquist, ws= 4000 / nyquist, gpass=1, gstop=18, ftype='ellip')
IIRBiquadFilter non_audio_hpf { non_audio_hpf_config };
};
#endif/*__DSP_SQUELCH_H__*/