Extract FMSquelch into separate files.

This commit is contained in:
Jared Boone 2015-08-27 09:59:03 -07:00
parent b904971ef2
commit de0777f476
4 changed files with 92 additions and 31 deletions

View File

@ -132,6 +132,7 @@ CPPSRC = main.cpp \
channel_decimator.cpp \
dsp_decimate.cpp \
dsp_demodulate.cpp \
dsp_squelch.cpp \
clock_recovery.cpp \
access_code_correlator.cpp \
packet_builder.cpp \

View File

@ -0,0 +1,45 @@
/*
* 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 <cstdint>
#include <array>
bool FMSquelch::execute(buffer_s16_t audio) {
// TODO: No hard-coded array size.
std::array<int16_t, N> squelch_energy_buffer;
const buffer_s16_t squelch_energy {
squelch_energy_buffer.data(),
squelch_energy_buffer.size()
};
non_audio_hpf.execute(audio, squelch_energy);
uint64_t max_squared = 0;
for(const auto sample : squelch_energy_buffer) {
const uint64_t sample_squared = sample * sample;
if( sample_squared > max_squared ) {
max_squared = sample_squared;
}
}
return (max_squared < (threshold * threshold));
}

View File

@ -0,0 +1,45 @@
/*
* 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__*/

View File

@ -46,6 +46,7 @@
#include "dsp_fir_taps.hpp"
#include "dsp_iir.hpp"
#include "dsp_iir_config.hpp"
#include "dsp_squelch.hpp"
#include "baseband_stats_collector.hpp"
#include "rssi_stats_collector.hpp"
@ -79,37 +80,6 @@
constexpr auto baseband_thread_priority = NORMALPRIO + 20;
constexpr auto rssi_thread_priority = NORMALPRIO + 10;
class FMSquelch {
public:
bool execute(buffer_s16_t audio) {
// TODO: No hard-coded array size.
std::array<int16_t, N> squelch_energy_buffer;
const buffer_s16_t squelch_energy {
squelch_energy_buffer.data(),
squelch_energy_buffer.size()
};
non_audio_hpf.execute(audio, squelch_energy);
uint64_t max_squared = 0;
for(const auto sample : squelch_energy_buffer) {
const uint64_t sample_squared = sample * sample;
if( sample_squared > max_squared ) {
max_squared = sample_squared;
}
}
return (max_squared < (threshold * threshold));
}
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 };
};
static volatile bool channel_spectrum_request_update { false };
static std::array<complex16_t, 256> channel_spectrum;
static uint32_t channel_spectrum_sampling_rate { 0 };