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sdrangel/plugins/channelrx/demodam/amdemodsink.cpp

328 lines
11 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019 Edouard Griffiths, F4EXB //
// //
// 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 as version 3 of the License, 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 V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#include <QDebug>
#include <complex.h>
#include "audio/audiooutput.h"
#include "dsp/fftfilt.h"
#include "util/db.h"
#include "util/stepfunctions.h"
#include "amdemodsink.h"
AMDemodSink::AMDemodSink() :
m_channelSampleRate(48000),
m_audioSampleRate(48000),
m_channelFrequencyOffset(0),
m_squelchCount(0),
m_squelchOpen(false),
m_squelchDelayLine(9600),
m_magsqSum(0.0f),
m_magsqPeak(0.0f),
m_magsqCount(0),
m_volumeAGC(0.003),
m_syncAMAGC(12000, 0.1, 1e-2),
m_audioFifo(48000)
{
m_audioBuffer.resize(1<<14);
m_audioBufferFill = 0;
m_magsq = 0.0;
DSBFilter = new fftfilt((2.0f * m_settings.m_rfBandwidth) / m_audioSampleRate, 2 * 1024);
SSBFilter = new fftfilt(0.0f, m_settings.m_rfBandwidth / m_audioSampleRate, 1024);
m_syncAMAGC.setThresholdEnable(false);
m_syncAMAGC.resize(12000, 6000, 0.1);
m_pllFilt.create(101, m_audioSampleRate, 200.0);
m_pll.computeCoefficients(0.05, 0.707, 1000);
m_syncAMBuffIndex = 0;
applySettings(m_settings, true);
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
}
AMDemodSink::~AMDemodSink()
{
delete DSBFilter;
delete SSBFilter;
}
void AMDemodSink::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end)
{
Complex ci;
for (SampleVector::const_iterator it = begin; it != end; ++it)
{
Complex c(it->real(), it->imag());
c *= m_nco.nextIQ();
if (m_interpolatorDistance < 1.0f) // interpolate
{
while (!m_interpolator.interpolate(&m_interpolatorDistanceRemain, c, &ci))
{
processOneSample(ci);
m_interpolatorDistanceRemain += m_interpolatorDistance;
}
}
else // decimate
{
if (m_interpolator.decimate(&m_interpolatorDistanceRemain, c, &ci))
{
processOneSample(ci);
m_interpolatorDistanceRemain += m_interpolatorDistance;
}
}
}
if (m_audioBufferFill > 0)
{
uint res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], m_audioBufferFill);
if (res != m_audioBufferFill) {
qDebug("AMDemodSink::feed: %u/%u tail samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
}
}
void AMDemodSink::processOneSample(Complex &ci)
{
Real re = ci.real() / SDR_RX_SCALEF;
Real im = ci.imag() / SDR_RX_SCALEF;
Real magsq = re*re + im*im;
m_movingAverage(magsq);
m_magsq = m_movingAverage.asDouble();
m_magsqSum += magsq;
if (magsq > m_magsqPeak)
{
m_magsqPeak = magsq;
}
m_magsqCount++;
m_squelchDelayLine.write(magsq);
if (m_magsq < m_squelchLevel)
{
if (m_squelchCount > 0) {
m_squelchCount--;
}
}
else
{
if (m_squelchCount < m_audioSampleRate / 10) {
m_squelchCount++;
}
}
qint16 sample;
m_squelchOpen = (m_squelchCount >= m_audioSampleRate / 20);
if (m_squelchOpen && !m_settings.m_audioMute)
{
Real demod;
if (m_settings.m_pll)
{
std::complex<float> s(re, im);
s = m_pllFilt.filter(s);
m_pll.feed(s.real(), s.imag());
float yr = re * m_pll.getImag() - im * m_pll.getReal();
float yi = re * m_pll.getReal() + im * m_pll.getImag();
fftfilt::cmplx *sideband;
std::complex<float> cs(yr, yi);
int n_out;
if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMDSB) {
n_out = DSBFilter->runDSB(cs, &sideband, false);
} else {
n_out = SSBFilter->runSSB(cs, &sideband, m_settings.m_syncAMOperation == AMDemodSettings::SyncAMUSB, false);
}
for (int i = 0; i < n_out; i++)
{
float agcVal = m_syncAMAGC.feedAndGetValue(sideband[i]);
fftfilt::cmplx z = sideband[i] * agcVal; // * m_syncAMAGC.getStepValue();
if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMDSB) {
m_syncAMBuff[i] = (z.real() + z.imag());
} else if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMUSB) {
m_syncAMBuff[i] = (z.real() + z.imag());
} else {
m_syncAMBuff[i] = (z.real() + z.imag());
}
m_syncAMBuffIndex = 0;
}
m_syncAMBuffIndex = m_syncAMBuffIndex < 2*1024 ? m_syncAMBuffIndex : 0;
demod = m_syncAMBuff[m_syncAMBuffIndex++]*4.0f; // mos pifometrico
}
else
{
demod = sqrt(m_squelchDelayLine.readBack(m_audioSampleRate/20));
m_volumeAGC.feed(demod);
demod = (demod - m_volumeAGC.getValue()) / m_volumeAGC.getValue();
}
if (m_settings.m_bandpassEnable)
{
demod = m_bandpass.filter(demod);
}
else
{
demod = m_lowpass.filter(demod);
}
Real attack = (m_squelchCount - 0.05f * m_audioSampleRate) / (0.05f * m_audioSampleRate);
sample = demod * StepFunctions::smootherstep(attack) * (m_audioSampleRate/24) * m_settings.m_volume;
}
else
{
sample = 0;
}
m_audioBuffer[m_audioBufferFill].l = sample;
m_audioBuffer[m_audioBufferFill].r = sample;
++m_audioBufferFill;
if (m_audioBufferFill >= m_audioBuffer.size())
{
uint res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], m_audioBufferFill);
if (res != m_audioBufferFill)
{
qDebug("AMDemodSink::processOneSample: %u/%u audio samples written", res, m_audioBufferFill);
m_audioFifo.clear();
}
m_audioBufferFill = 0;
}
}
void AMDemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
{
qDebug() << "AMDemodSink::applyChannelSettings:"
<< " channelSampleRate: " << channelSampleRate
<< " channelFrequencyOffset: " << channelFrequencyOffset
<< " m_audioSampleRate: " << m_audioSampleRate;
if ((m_channelFrequencyOffset != channelFrequencyOffset) ||
(m_channelSampleRate != channelSampleRate) || force)
{
m_nco.setFreq(-channelFrequencyOffset, channelSampleRate);
}
if ((m_channelSampleRate != channelSampleRate) || force)
{
m_interpolator.create(16, channelSampleRate, m_settings.m_rfBandwidth / 2.2f);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) channelSampleRate / (Real) m_audioSampleRate;
}
m_channelSampleRate = channelSampleRate;
m_channelFrequencyOffset = channelFrequencyOffset;
}
void AMDemodSink::applySettings(const AMDemodSettings& settings, bool force)
{
qDebug() << "AMDemodSink::applySettings:"
<< " m_inputFrequencyOffset: " << settings.m_inputFrequencyOffset
<< " m_rfBandwidth: " << settings.m_rfBandwidth
<< " m_volume: " << settings.m_volume
<< " m_squelch: " << settings.m_squelch
<< " m_audioMute: " << settings.m_audioMute
<< " m_bandpassEnable: " << settings.m_bandpassEnable
<< " m_audioDeviceName: " << settings.m_audioDeviceName
<< " m_pll: " << settings.m_pll
<< " m_syncAMOperation: " << (int) settings.m_syncAMOperation
<< " force: " << force;
if((m_settings.m_rfBandwidth != settings.m_rfBandwidth) ||
(m_settings.m_bandpassEnable != settings.m_bandpassEnable) || force)
{
m_interpolator.create(16, m_channelSampleRate, settings.m_rfBandwidth / 2.2f);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) m_audioSampleRate;
m_bandpass.create(301, m_audioSampleRate, 300.0, settings.m_rfBandwidth / 2.0f);
m_lowpass.create(301, m_audioSampleRate, settings.m_rfBandwidth / 2.0f);
DSBFilter->create_dsb_filter((2.0f * settings.m_rfBandwidth) / (float) m_audioSampleRate);
}
if ((m_settings.m_squelch != settings.m_squelch) || force) {
m_squelchLevel = CalcDb::powerFromdB(settings.m_squelch);
}
if ((m_settings.m_pll != settings.m_pll) || force)
{
if (settings.m_pll)
{
m_volumeAGC.resizeNew(m_audioSampleRate/4, 0.003);
m_syncAMBuffIndex = 0;
}
else
{
m_volumeAGC.resizeNew(m_audioSampleRate/10, 0.003);
}
}
if ((m_settings.m_syncAMOperation != settings.m_syncAMOperation) || force) {
m_syncAMBuffIndex = 0;
}
m_settings = settings;
}
void AMDemodSink::applyAudioSampleRate(int sampleRate)
{
if (sampleRate < 0)
{
qWarning("AMDemodSink::applyAudioSampleRate: invalid sample rate: %d", sampleRate);
return;
}
qDebug("AMDemodSink::applyAudioSampleRate: sampleRate: %d m_channelSampleRate: %d", sampleRate, m_channelSampleRate);
m_interpolator.create(16, m_channelSampleRate, m_settings.m_rfBandwidth / 2.2f);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) sampleRate;
m_bandpass.create(301, sampleRate, 300.0, m_settings.m_rfBandwidth / 2.0f);
m_lowpass.create(301, sampleRate, m_settings.m_rfBandwidth / 2.0f);
m_audioFifo.setSize(sampleRate);
m_squelchDelayLine.resize(sampleRate/5);
DSBFilter->create_dsb_filter((2.0f * m_settings.m_rfBandwidth) / (float) sampleRate);
m_pllFilt.create(101, sampleRate, 200.0);
if (m_settings.m_pll) {
m_volumeAGC.resizeNew(sampleRate, 0.003);
} else {
m_volumeAGC.resizeNew(sampleRate/10, 0.003);
}
m_syncAMAGC.resize(sampleRate/4, sampleRate/8, 0.1);
m_pll.setSampleRate(sampleRate);
m_audioSampleRate = sampleRate;
}