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sdrangel/plugins/channelrx/demodft8/ft8demodsink.cpp

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///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
// //
// 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 <stdio.h>
#include <QTime>
#include <QDebug>
#include "dsp/spectrumvis.h"
#include "dsp/datafifo.h"
#include "util/messagequeue.h"
#include "maincore.h"
#include "ft8buffer.h"
#include "ft8demodsink.h"
const int FT8DemodSink::m_ssbFftLen = 1024;
const int FT8DemodSink::m_agcTarget = 3276; // 32768/10 -10 dB amplitude => -20 dB power: center of normal signal
FT8DemodSink::LevelRMS::LevelRMS()
{
m_sum = 0.0f;
m_peak = 0.0f;
m_n = 0;
m_reset = true;
}
void FT8DemodSink::LevelRMS::accumulate(float level)
{
if (m_reset)
{
m_sum = level * level;
m_peak = std::fabs(level);
m_n = 1;
m_reset = false;
}
else
{
m_sum += level * level;
m_peak = std::max(m_peak, std::fabs(level));
m_n++;
}
}
FT8DemodSink::FT8DemodSink() :
m_agc(12000, m_agcTarget, 1e-2),
m_agcActive(false),
m_audioActive(false),
m_spectrumSink(nullptr),
m_ft8Buffer(nullptr),
m_levelInNbSamples(1200) // 100 ms
{
m_Bandwidth = 5000;
m_LowCutoff = 300;
m_volume = 2.0;
m_spanLog2 = 3;
m_channelSampleRate = 48000;
m_channelFrequencyOffset = 0;
m_undersampleCount = 0;
m_sum = 0;
m_demodBuffer.resize(1<<12);
m_demodBufferFill = 0;
m_usb = true;
m_magsq = 0.0f;
m_magsqSum = 0.0f;
m_magsqPeak = 0.0f;
m_magsqCount = 0;
m_agc.setThresholdEnable(false); // no squelch
SSBFilter = new fftfilt(m_LowCutoff / FT8DemodSettings::m_ft8SampleRate, m_Bandwidth / FT8DemodSettings::m_ft8SampleRate, m_ssbFftLen);
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
applySettings(m_settings, true);
}
FT8DemodSink::~FT8DemodSink()
{
delete SSBFilter;
}
void FT8DemodSink::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end)
{
if (m_channelSampleRate == 0) {
return;
}
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
{
if (m_interpolator.decimate(&m_interpolatorDistanceRemain, c, &ci))
{
processOneSample(ci);
m_interpolatorDistanceRemain += m_interpolatorDistance;
}
}
}
}
void FT8DemodSink::processOneSample(Complex &ci)
{
fftfilt::cmplx *sideband;
int n_out = 0;
int decim = 1<<(m_spanLog2 - 1);
unsigned char decim_mask = decim - 1; // counter LSB bit mask for decimation by 2^(m_scaleLog2 - 1)
n_out = SSBFilter->runSSB(ci, &sideband, m_usb);
for (int i = 0; i < n_out; i++)
{
// Downsample by 2^(m_scaleLog2 - 1) for SSB band spectrum display
// smart decimation with bit gain using float arithmetic (23 bits significand)
m_sum += sideband[i];
if (!(m_undersampleCount++ & decim_mask))
{
Real avgr = m_sum.real() / decim;
Real avgi = m_sum.imag() / decim;
m_magsq = (avgr * avgr + avgi * avgi) / (SDR_RX_SCALED*SDR_RX_SCALED);
m_magsqSum += m_magsq;
if (m_magsq > m_magsqPeak)
{
m_magsqPeak = m_magsq;
}
m_magsqCount++;
m_sampleBuffer.push_back(Sample(avgr, avgi));
m_sum.real(0.0);
m_sum.imag(0.0);
}
float agcVal = m_agcActive ? m_agc.feedAndGetValue(sideband[i]) : 0.1;
fftfilt::cmplx z = sideband[i]*agcVal;
m_audioActive = z.real() != 0.0;
Real demod = (z.real() + z.imag()) * 0.7;
qint16 sample = (qint16)(demod * m_volume);
if (m_ft8Buffer) {
m_ft8Buffer->feed(sample);
}
m_demodBuffer[m_demodBufferFill++] = sample;
calculateLevel(sample);
if (m_demodBufferFill >= m_demodBuffer.size())
{
QList<ObjectPipe*> dataPipes;
MainCore::instance()->getDataPipes().getDataPipes(m_channel, "demod", dataPipes);
if (dataPipes.size() > 0)
{
QList<ObjectPipe*>::iterator it = dataPipes.begin();
for (; it != dataPipes.end(); ++it)
{
DataFifo *fifo = qobject_cast<DataFifo*>((*it)->m_element);
if (fifo)
{
fifo->write(
(quint8*) &m_demodBuffer[0],
m_demodBuffer.size() * sizeof(qint16),
DataFifo::DataTypeI16
);
}
}
}
m_demodBufferFill = 0;
}
}
if (m_spectrumSink && (m_sampleBuffer.size() != 0))
{
m_spectrumSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), true);
m_sampleBuffer.clear();
}
}
void FT8DemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
{
qDebug() << "FT8DemodSink::applyChannelSettings:"
<< " channelSampleRate: " << channelSampleRate
<< " channelFrequencyOffset: " << channelFrequencyOffset;
if ((m_channelFrequencyOffset != channelFrequencyOffset) ||
(m_channelSampleRate != channelSampleRate) || force)
{
m_nco.setFreq(-channelFrequencyOffset, channelSampleRate);
}
if ((m_channelSampleRate != channelSampleRate) || force)
{
Real interpolatorBandwidth = (m_Bandwidth * 1.5f) > channelSampleRate ? channelSampleRate : (m_Bandwidth * 1.5f);
m_interpolator.create(16, channelSampleRate, interpolatorBandwidth, 2.0f);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) channelSampleRate / (Real) FT8DemodSettings::m_ft8SampleRate;
}
m_channelSampleRate = channelSampleRate;
m_channelFrequencyOffset = channelFrequencyOffset;
}
void FT8DemodSink::applyFT8SampleRate()
{
qDebug("FT8DemodSink::applyFT8SampleRate: %d", FT8DemodSettings::m_ft8SampleRate);
Real interpolatorBandwidth = (m_Bandwidth * 1.5f) > m_channelSampleRate ? m_channelSampleRate : (m_Bandwidth * 1.5f);
m_interpolator.create(16, m_channelSampleRate, interpolatorBandwidth, 2.0f);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) FT8DemodSettings::m_ft8SampleRate;
SSBFilter->create_filter(m_LowCutoff / (float) FT8DemodSettings::m_ft8SampleRate, m_Bandwidth / (float) FT8DemodSettings::m_ft8SampleRate, m_settings.m_filterBank[m_settings.m_filterIndex].m_fftWindow);
m_levelInNbSamples = FT8DemodSettings::m_ft8SampleRate / 10; // 100 ms
QList<ObjectPipe*> pipes;
MainCore::instance()->getMessagePipes().getMessagePipes(m_channel, "reportdemod", pipes);
if (pipes.size() > 0)
{
for (const auto& pipe : pipes)
{
MessageQueue* messageQueue = qobject_cast<MessageQueue*>(pipe->m_element);
if (messageQueue)
{
MainCore::MsgChannelDemodReport *msg = MainCore::MsgChannelDemodReport::create(m_channel, FT8DemodSettings::m_ft8SampleRate);
messageQueue->push(msg);
}
}
}
}
void FT8DemodSink::applySettings(const FT8DemodSettings& settings, bool force)
{
qDebug() << "FT8DemodSink::applySettings:"
<< " m_inputFrequencyOffset: " << settings.m_inputFrequencyOffset
<< " m_filterIndex: " << settings.m_filterIndex
<< " [m_spanLog2: " << settings.m_filterBank[settings.m_filterIndex].m_spanLog2
<< " m_rfBandwidth: " << settings.m_filterBank[settings.m_filterIndex].m_rfBandwidth
<< " m_lowCutoff: " << settings.m_filterBank[settings.m_filterIndex].m_lowCutoff
<< " m_fftWindow: " << settings.m_filterBank[settings.m_filterIndex].m_fftWindow << "]"
<< " m_volume: " << settings.m_volume
<< " m_agcActive: " << settings.m_agc
<< " m_streamIndex: " << settings.m_streamIndex
<< " m_useReverseAPI: " << settings.m_useReverseAPI
<< " m_reverseAPIAddress: " << settings.m_reverseAPIAddress
<< " m_reverseAPIPort: " << settings.m_reverseAPIPort
<< " m_reverseAPIDeviceIndex: " << settings.m_reverseAPIDeviceIndex
<< " m_reverseAPIChannelIndex: " << settings.m_reverseAPIChannelIndex
<< " force: " << force;
if((m_settings.m_filterBank[m_settings.m_filterIndex].m_rfBandwidth != settings.m_filterBank[settings.m_filterIndex].m_rfBandwidth) ||
(m_settings.m_filterBank[m_settings.m_filterIndex].m_lowCutoff != settings.m_filterBank[settings.m_filterIndex].m_lowCutoff) ||
(m_settings.m_filterBank[m_settings.m_filterIndex].m_fftWindow != settings.m_filterBank[settings.m_filterIndex].m_fftWindow) || force)
{
float band, lowCutoff;
band = settings.m_filterBank[settings.m_filterIndex].m_rfBandwidth;
lowCutoff = settings.m_filterBank[settings.m_filterIndex].m_lowCutoff;
if (band < 0) {
band = -band;
lowCutoff = -lowCutoff;
m_usb = false;
} else {
m_usb = true;
}
if (band < 100.0f)
{
band = 100.0f;
lowCutoff = 0;
}
m_Bandwidth = band;
m_LowCutoff = lowCutoff;
Real interpolatorBandwidth = (m_Bandwidth * 1.5f) > m_channelSampleRate ? m_channelSampleRate : (m_Bandwidth * 1.5f);
m_interpolator.create(16, m_channelSampleRate, interpolatorBandwidth, 2.0f);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) FT8DemodSettings::m_ft8SampleRate;
SSBFilter->create_filter(m_LowCutoff / (float) FT8DemodSettings::m_ft8SampleRate, m_Bandwidth / (float) FT8DemodSettings::m_ft8SampleRate, settings.m_filterBank[settings.m_filterIndex].m_fftWindow);
}
if ((m_settings.m_volume != settings.m_volume) || force)
{
m_volume = settings.m_volume;
m_volume /= 4.0; // for 3276.8
}
m_spanLog2 = settings.m_filterBank[settings.m_filterIndex].m_spanLog2;
m_agcActive = settings.m_agc;
m_settings = settings;
}
void FT8DemodSink::calculateLevel(int16_t& sample)
{
if (m_levelIn.m_n >= m_levelInNbSamples)
{
m_rmsLevel = sqrt(m_levelIn.m_sum / m_levelInNbSamples);
m_peakLevel = m_levelIn.m_peak;
m_levelIn.m_reset = true;
}
m_levelIn.accumulate(sample/29491.2f); // scale on 90% (0.9 * 32768.0)
}
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