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sdrangel/plugins/channelrx/demodendoftrain/endoftraindemodsink.cpp
2024-04-11 23:31:34 +02:00

365 lines
13 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2021-2024 Jon Beniston, M7RCE <jon@beniston.com> //
// Copyright (C) 2021-2022 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 <QDebug>
#include "dsp/datafifo.h"
#include "device/deviceapi.h"
#include "channel/channelwebapiutils.h"
#include "maincore.h"
#include "endoftraindemod.h"
#include "endoftraindemodsink.h"
EndOfTrainDemodSink::EndOfTrainDemodSink(EndOfTrainDemod *endoftrainDemod) :
m_scopeSink(nullptr),
m_endoftrainDemod(endoftrainDemod),
m_channelSampleRate(EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE),
m_channelFrequencyOffset(0),
m_magsqSum(0.0f),
m_magsqPeak(0.0f),
m_magsqCount(0),
m_messageQueueToChannel(nullptr),
m_f1(nullptr),
m_f0(nullptr),
m_corrBuf(nullptr),
m_corrIdx(0),
m_corrCnt(0),
m_sampleBufferIndex(0)
{
m_magsq = 0.0;
m_demodBuffer.resize(1<<12);
m_demodBufferFill = 0;
for (int i = 0; i < EndOfTrainDemodSettings::m_scopeStreams; i++) {
m_sampleBuffer[i].resize(m_sampleBufferSize);
}
applySettings(m_settings, QStringList(), true);
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
}
EndOfTrainDemodSink::~EndOfTrainDemodSink()
{
delete[] m_f1;
delete[] m_f0;
delete[] m_corrBuf;
}
void EndOfTrainDemodSink::sampleToScope(Complex sample, Real s1, Real s2, Real s3, Real s4, Real s5, Real s6, Real s7, Real s8)
{
if (m_scopeSink)
{
m_sampleBuffer[0][m_sampleBufferIndex] = sample;
m_sampleBuffer[1][m_sampleBufferIndex] = Complex(s1, 0.0f);
m_sampleBuffer[2][m_sampleBufferIndex] = Complex(s2, 0.0f);
m_sampleBuffer[3][m_sampleBufferIndex] = Complex(s3, 0.0f);
m_sampleBuffer[4][m_sampleBufferIndex] = Complex(s4, 0.0f);
m_sampleBuffer[5][m_sampleBufferIndex] = Complex(s5, 0.0f);
m_sampleBuffer[6][m_sampleBufferIndex] = Complex(s6, 0.0f);
m_sampleBuffer[7][m_sampleBufferIndex] = Complex(s7, 0.0f);
m_sampleBuffer[8][m_sampleBufferIndex] = Complex(s8, 0.0f);
m_sampleBufferIndex++;
if (m_sampleBufferIndex == m_sampleBufferSize)
{
std::vector<ComplexVector::const_iterator> vbegin;
for (int i = 0; i < EndOfTrainDemodSettings::m_scopeStreams; i++) {
vbegin.push_back(m_sampleBuffer[i].begin());
}
m_scopeSink->feed(vbegin, m_sampleBufferSize);
m_sampleBufferIndex = 0;
}
}
}
void EndOfTrainDemodSink::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;
}
}
}
}
void EndOfTrainDemodSink::processOneSample(Complex &ci)
{
Complex ca;
// FM demodulation
double magsqRaw;
Real deviation;
Real fmDemod = m_phaseDiscri.phaseDiscriminatorDelta(ci, magsqRaw, deviation);
// Calculate average and peak levels for level meter
Real magsq = magsqRaw / (SDR_RX_SCALED*SDR_RX_SCALED);
m_movingAverage(magsq);
m_magsq = m_movingAverage.asDouble();
m_magsqSum += magsq;
if (magsq > m_magsqPeak)
{
m_magsqPeak = magsq;
}
m_magsqCount++;
Real f0Filt = 0.0f;
Real f1Filt = 0.0f;
float diff = 0.0;
int sample = 0;
int bit = 0;
m_corrBuf[m_corrIdx] = fmDemod;
if (m_corrCnt >= m_correlationLength)
{
// Correlate with 1200 + 1800 baud complex exponentials
Complex corrF0 = 0.0f;
Complex corrF1 = 0.0f;
for (int i = 0; i < m_correlationLength; i++)
{
int j = m_corrIdx - i;
if (j < 0)
j += m_correlationLength;
corrF0 += m_f0[i] * m_corrBuf[j];
corrF1 += m_f1[i] * m_corrBuf[j];
}
m_corrCnt--; // Avoid overflow in increment below
// Low pass filter, to minimize changes above the baud rate
f0Filt = m_lowpassF0.filter(std::abs(corrF0));
f1Filt = m_lowpassF1.filter(std::abs(corrF1));
// Determine which is the closest match and then quantise to 1 or -1
diff = f1Filt - f0Filt;
sample = diff >= 0.0f ? 1 : 0;
// Look for edge
if (sample != m_samplePrev)
{
m_syncCount = EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE/EndOfTrainDemodSettings::BAUD_RATE/2;
}
else
{
m_syncCount--;
if (m_syncCount <= 0)
{
bit = sample;
// Store in shift reg - LSB first
m_bits |= bit << m_bitCount;
m_bitCount++;
if (!m_gotSOP)
{
if (m_bitCount >= 17)
{
// Look for frame sync
if ((m_bits & 0x1ffff) == 0x91D5)
{
// Start of packet
m_gotSOP = true;
m_bits = 0;
m_bitCount = 0;
m_byteCount = 0;
}
else
{
m_bitCount--;
m_bits >>= 1;
}
}
}
else
{
if (m_bitCount == 8)
{
if (m_byteCount == 8)
{
QByteArray rxPacket((char *)m_bytes, m_byteCount);
//qDebug() << "RX: " << rxPacket.toHex();
if (getMessageQueueToChannel())
{
QDateTime dateTime = QDateTime::currentDateTime();
if (m_settings.m_useFileTime)
{
QString hardwareId = m_endoftrainDemod->getDeviceAPI()->getHardwareId();
if ((hardwareId == "FileInput") || (hardwareId == "SigMFFileInput"))
{
QString dateTimeStr;
int deviceIdx = m_endoftrainDemod->getDeviceSetIndex();
if (ChannelWebAPIUtils::getDeviceReportValue(deviceIdx, "absoluteTime", dateTimeStr)) {
dateTime = QDateTime::fromString(dateTimeStr, Qt::ISODateWithMs);
}
}
}
MainCore::MsgPacket *msg = MainCore::MsgPacket::create(m_endoftrainDemod, rxPacket, dateTime);
getMessageQueueToChannel()->push(msg);
}
// Reset state to start receiving next packet
m_gotSOP = false;
m_bits = 0;
m_bitCount = 0;
m_byteCount = 0;
}
else
{
m_bytes[m_byteCount] = m_bits;
m_byteCount++;
}
m_bits = 0;
m_bitCount = 0;
}
}
m_syncCount = EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE/EndOfTrainDemodSettings::BAUD_RATE;
}
}
m_samplePrev = sample;
}
m_corrIdx = (m_corrIdx + 1) % m_correlationLength;
m_corrCnt++;
// Select signals to feed to scope
sampleToScope(ci / SDR_RX_SCALEF, magsq, fmDemod, f0Filt, f1Filt, diff, sample, bit, m_gotSOP);
// Send demod signal to Demod Analzyer feature
m_demodBuffer[m_demodBufferFill++] = fmDemod * std::numeric_limits<int16_t>::max();
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;
}
}
void EndOfTrainDemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
{
qDebug() << "EndOfTrainDemodSink::applyChannelSettings:"
<< " channelSampleRate: " << channelSampleRate
<< " channelFrequencyOffset: " << channelFrequencyOffset;
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 / 2.2);
m_interpolatorDistance = (Real) channelSampleRate / (Real) EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE;
m_interpolatorDistanceRemain = m_interpolatorDistance;
}
m_channelSampleRate = channelSampleRate;
m_channelFrequencyOffset = channelFrequencyOffset;
}
void EndOfTrainDemodSink::applySettings(const EndOfTrainDemodSettings& settings, const QStringList& settingsKeys, bool force)
{
qDebug() << "EndOfTrainDemodSink::applySettings:"
<< settings.getDebugString(settingsKeys, force)
<< " force: " << force;
if (settingsKeys.contains("rfBandwidth") || force)
{
m_interpolator.create(16, m_channelSampleRate, settings.m_rfBandwidth / 2.2);
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE;
m_interpolatorDistanceRemain = m_interpolatorDistance;
}
if (settingsKeys.contains("fmDeviation") || force)
{
m_phaseDiscri.setFMScaling(EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE / (2.0f * settings.m_fmDeviation));
}
if (force)
{
delete[] m_f1;
delete[] m_f0;
delete[] m_corrBuf;
m_correlationLength = EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE/EndOfTrainDemodSettings::BAUD_RATE;
m_f1 = new Complex[m_correlationLength]();
m_f0 = new Complex[m_correlationLength]();
m_corrBuf = new Complex[m_correlationLength]();
m_corrIdx = 0;
m_corrCnt = 0;
Real f0 = 0.0f;
Real f1 = 0.0f;
for (int i = 0; i < m_correlationLength; i++)
{
m_f0[i] = Complex(cos(f0), sin(f0));
m_f1[i] = Complex(cos(f1), sin(f1));
f0 += 2.0f*(Real)M_PI*1800.0f/EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE;
f1 += 2.0f*(Real)M_PI*1200.0f/EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE;
}
m_lowpassF1.create(301, EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE, EndOfTrainDemodSettings::BAUD_RATE * 1.1f);
m_lowpassF0.create(301, EndOfTrainDemodSettings::CHANNEL_SAMPLE_RATE, EndOfTrainDemodSettings::BAUD_RATE * 1.1f);
m_samplePrev = 0;
m_syncCount = 0;
m_bits = 0;
m_bitCount = 0;
m_gotSOP = false;
m_byteCount = 0;
}
if (force) {
m_settings = settings;
} else {
m_settings.applySettings(settingsKeys, settings);
}
}