sdrangel/plugins/channelrx/demodbfm/bfmdemodsink.cpp

380 lines
13 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019-2020, 2022-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
// Copyright (C) 2022 Jon Beniston, M7RCE <jon@beniston.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 <complex.h>
#include <QTime>
#include <QDebug>
#include "dsp/basebandsamplesink.h"
#include "dsp/datafifo.h"
#include "pipes/datapipes.h"
#include "maincore.h"
#include "rdsparser.h"
#include "bfmdemodsink.h"
const Real BFMDemodSink::default_deemphasis = 50.0; // 50 us
const int BFMDemodSink::default_excursion = 750000; // +/- 75 kHz
BFMDemodSink::BFMDemodSink() :
m_channel(nullptr),
m_channelSampleRate(48000),
m_channelFrequencyOffset(0),
m_audioSampleRate(48000),
m_audioBufferFill(0),
m_audioFifo(48000),
m_pilotPLL(19000/384000, 50/384000, 0.01),
m_deemphasisFilterX(default_deemphasis * 48000 * 1.0e-6),
m_deemphasisFilterY(default_deemphasis * 48000 * 1.0e-6),
m_fmExcursion(default_excursion)
{
m_magsq = 0.0f;
m_magsqSum = 0.0f;
m_magsqPeak = 0.0f;
m_magsqCount = 0;
m_squelchLevel = 0;
m_squelchState = 0;
m_interpolatorDistance = 0.0f;
m_interpolatorDistanceRemain = 0.0f;
m_interpolatorRDSDistance = 0.0f;
m_interpolatorRDSDistanceRemain = 0.0f;
m_interpolatorStereoDistance = 0.0f;
m_interpolatorStereoDistanceRemain = 0.0f;
m_spectrumSink = nullptr;
m_m1Arg = 0;
m_rfFilter = new fftfilt(-50000.0 / 384000.0, 50000.0 / 384000.0, filtFftLen);
m_deemphasisFilterX.configure(default_deemphasis * m_audioSampleRate * 1.0e-6);
m_deemphasisFilterY.configure(default_deemphasis * m_audioSampleRate * 1.0e-6);
m_phaseDiscri.setFMScaling(384000/m_fmExcursion);
m_audioBuffer.resize(1<<14);
m_audioBufferFill = 0;
m_demodBuffer.resize(1<<13);
m_demodBufferFill = 0;
applySettings(m_settings, true);
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
}
BFMDemodSink::~BFMDemodSink()
{
delete m_rfFilter;
}
void BFMDemodSink::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end)
{
Complex ci, cs, cr;
fftfilt::cmplx *rf;
int rf_out;
double msq;
Real demod;
m_sampleBuffer.clear();
for (SampleVector::const_iterator it = begin; it != end; ++it)
{
Complex c(it->real() / SDR_RX_SCALEF, it->imag() / SDR_RX_SCALEF);
c *= m_nco.nextIQ();
rf_out = m_rfFilter->runFilt(c, &rf); // filter RF before demod
for (int i =0 ; i <rf_out; i++)
{
msq = rf[i].real()*rf[i].real() + rf[i].imag()*rf[i].imag();
m_magsqSum += msq;
if (msq > m_magsqPeak) {
m_magsqPeak = msq;
}
m_magsqCount++;
if (msq >= m_squelchLevel)
{
if (m_squelchState < m_settings.m_rfBandwidth / 10) { // twice attack and decay rate
m_squelchState++;
}
}
else
{
if (m_squelchState > 0) {
m_squelchState--;
}
}
if (m_squelchState > m_settings.m_rfBandwidth / 20) { // squelch open
demod = m_phaseDiscri.phaseDiscriminator(rf[i]);
} else {
demod = 0;
}
if (!m_settings.m_showPilot) {
m_sampleBuffer.push_back(Sample(demod * SDR_RX_SCALEF, 0.0));
}
if (m_settings.m_rdsActive)
{
//Complex r(demod * 2.0 * std::cos(3.0 * m_pilotPLLSamples[3]), 0.0);
Complex r(demod * 2.0 * std::cos(3.0 * m_pilotPLLSamples[3]), 0.0);
if (m_interpolatorRDS.decimate(&m_interpolatorRDSDistanceRemain, r, &cr))
{
bool bit;
if (m_rdsDemod.process(cr.real(), bit))
{
if (m_rdsDecoder.frameSync(bit)) {
m_rdsParser.parseGroup(m_rdsDecoder.getGroup());
}
}
m_interpolatorRDSDistanceRemain += m_interpolatorRDSDistance;
}
}
Real sampleStereo = 0.0f;
// Process stereo if stereo mode is selected
if (m_settings.m_audioStereo)
{
m_pilotPLL.process(demod, m_pilotPLLSamples);
if (m_settings.m_showPilot) {
m_sampleBuffer.push_back(Sample(m_pilotPLLSamples[1] * SDR_RX_SCALEF, 0.0)); // debug 38 kHz pilot
}
if (m_settings.m_lsbStereo)
{
// 1.17 * 0.7 = 0.819
Complex s(demod * m_pilotPLLSamples[1], demod * m_pilotPLLSamples[2]);
if (m_interpolatorStereo.decimate(&m_interpolatorStereoDistanceRemain, s, &cs))
{
sampleStereo = cs.real() + cs.imag();
m_interpolatorStereoDistanceRemain += m_interpolatorStereoDistance;
}
}
else
{
Complex s(demod * 1.17 * m_pilotPLLSamples[1], 0);
if (m_interpolatorStereo.decimate(&m_interpolatorStereoDistanceRemain, s, &cs))
{
sampleStereo = cs.real();
m_interpolatorStereoDistanceRemain += m_interpolatorStereoDistance;
}
}
}
Complex e(demod, 0);
if (m_interpolator.decimate(&m_interpolatorDistanceRemain, e, &ci))
{
if (m_settings.m_audioStereo)
{
Real deemph_l, deemph_r; // Pre-emphasis is applied on each channel before multiplexing
m_deemphasisFilterX.process(ci.real() + sampleStereo, deemph_l);
m_deemphasisFilterY.process(ci.real() - sampleStereo, deemph_r);
m_audioBuffer[m_audioBufferFill].l = (qint16)(deemph_l * (1<<12) * m_settings.m_volume);
m_audioBuffer[m_audioBufferFill].r = (qint16)(deemph_r * (1<<12) * m_settings.m_volume);
}
else
{
Real deemph;
m_deemphasisFilterX.process(ci.real(), deemph);
quint16 sample = (qint16)(deemph * (1<<12) * m_settings.m_volume);
m_audioBuffer[m_audioBufferFill].l = sample;
m_audioBuffer[m_audioBufferFill].r = sample;
}
m_demodBuffer[m_demodBufferFill++] = m_audioBuffer[m_audioBufferFill].l;
m_demodBuffer[m_demodBufferFill++] = m_audioBuffer[m_audioBufferFill].r;
++m_audioBufferFill;
if (m_audioBufferFill >= m_audioBuffer.size())
{
std::size_t res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], std::min(m_audioBufferFill, m_audioBuffer.size()));
if(res != m_audioBufferFill) {
qDebug("BFMDemodSink::feed: %lu/%lu audio samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
}
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::DataTypeCI16);
}
}
}
m_demodBufferFill = 0;
}
m_interpolatorDistanceRemain += m_interpolatorDistance;
}
}
}
if (m_spectrumSink && (m_sampleBuffer.size() != 0))
{
m_spectrumSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), true);
m_sampleBuffer.clear();
}
}
void BFMDemodSink::applyAudioSampleRate(int sampleRate)
{
if (sampleRate < 0)
{
qWarning("BFMDemodSink::applyAudioSampleRate: invalid sample rate: %d", sampleRate);
return;
}
qDebug("BFMDemodSink::applyAudioSampleRate: %u", sampleRate);
m_interpolator.create(16, m_channelSampleRate, m_settings.m_afBandwidth);
m_interpolatorDistanceRemain = (Real) m_channelSampleRate / sampleRate;
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) sampleRate;
m_interpolatorStereo.create(16, m_channelSampleRate, m_settings.m_afBandwidth);
m_interpolatorStereoDistanceRemain = (Real) m_channelSampleRate / sampleRate;
m_interpolatorStereoDistance = (Real) m_channelSampleRate / (Real) sampleRate;
m_deemphasisFilterX.configure(default_deemphasis * sampleRate * 1.0e-6);
m_deemphasisFilterY.configure(default_deemphasis * sampleRate * 1.0e-6);
m_audioSampleRate = sampleRate;
}
void BFMDemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
{
qDebug() << "BFMDemodSink::applyChannelSettings:"
<< " channelSampleRate: " << channelSampleRate
<< " channelFrequencyOffset: " << channelFrequencyOffset;
if((channelFrequencyOffset != m_channelFrequencyOffset) ||
(channelSampleRate != m_channelSampleRate) || force)
{
m_nco.setFreq(-channelFrequencyOffset, channelSampleRate);
}
if ((channelSampleRate != m_channelSampleRate) || force)
{
m_pilotPLL.configure(19000.0/channelSampleRate, 50.0/channelSampleRate, 0.01);
m_interpolator.create(16, channelSampleRate, m_settings.m_afBandwidth);
m_interpolatorDistanceRemain = (Real) channelSampleRate / m_audioSampleRate;
m_interpolatorDistance = (Real) channelSampleRate / (Real) m_audioSampleRate;
m_interpolatorStereo.create(16, channelSampleRate, m_settings.m_afBandwidth);
m_interpolatorStereoDistanceRemain = (Real) channelSampleRate / m_audioSampleRate;
m_interpolatorStereoDistance = (Real) channelSampleRate / (Real) m_audioSampleRate;
m_interpolatorRDS.create(4, channelSampleRate, 600.0);
m_interpolatorRDSDistanceRemain = (Real) channelSampleRate / 250000.0;
m_interpolatorRDSDistance = (Real) channelSampleRate / 250000.0;
Real lowCut = -(m_settings.m_rfBandwidth / 2.0) / channelSampleRate;
Real hiCut = (m_settings.m_rfBandwidth / 2.0) / channelSampleRate;
m_rfFilter->create_filter(lowCut, hiCut);
m_phaseDiscri.setFMScaling(channelSampleRate / m_fmExcursion);
}
m_channelSampleRate = channelSampleRate;
m_channelFrequencyOffset = channelFrequencyOffset;
}
void BFMDemodSink::applySettings(const BFMDemodSettings& settings, bool force)
{
qDebug() << "BFMDemodSink::applySettings: MsgConfigureBFMDemod:"
<< " m_inputFrequencyOffset: " << settings.m_inputFrequencyOffset
<< " m_rfBandwidth: " << settings.m_rfBandwidth
<< " m_afBandwidth: " << settings.m_afBandwidth
<< " m_volume: " << settings.m_volume
<< " m_squelch: " << settings.m_squelch
<< " m_audioStereo: " << settings.m_audioStereo
<< " m_lsbStereo: " << settings.m_lsbStereo
<< " m_showPilot: " << settings.m_showPilot
<< " m_rdsActive: " << settings.m_rdsActive
<< " m_audioDeviceName: " << settings.m_audioDeviceName
<< " m_streamIndex: " << settings.m_streamIndex
<< " m_useReverseAPI: " << settings.m_useReverseAPI
<< " force: " << force;
if ((settings.m_audioStereo && (settings.m_audioStereo != m_settings.m_audioStereo)) || force) {
m_pilotPLL.configure(19000.0/m_channelSampleRate, 50.0/m_channelSampleRate, 0.01);
}
if ((settings.m_afBandwidth != m_settings.m_afBandwidth) || force)
{
m_interpolator.create(16, m_channelSampleRate, settings.m_afBandwidth);
m_interpolatorDistanceRemain = (Real) m_channelSampleRate / m_audioSampleRate;
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) m_audioSampleRate;
m_interpolatorStereo.create(16, m_channelSampleRate, settings.m_afBandwidth);
m_interpolatorStereoDistanceRemain = (Real) m_channelSampleRate / m_audioSampleRate;
m_interpolatorStereoDistance = (Real) m_channelSampleRate / (Real) m_audioSampleRate;
m_interpolatorRDS.create(4, m_channelSampleRate, 600.0);
m_interpolatorRDSDistanceRemain = (Real) m_channelSampleRate / 250000.0;
m_interpolatorRDSDistance = (Real) m_channelSampleRate / 250000.0;
m_lowpass.create(21, m_audioSampleRate, settings.m_afBandwidth);
}
if ((settings.m_rfBandwidth != m_settings.m_rfBandwidth) || force)
{
Real lowCut = -(settings.m_rfBandwidth / 2.0) / m_channelSampleRate;
Real hiCut = (settings.m_rfBandwidth / 2.0) / m_channelSampleRate;
m_rfFilter->create_filter(lowCut, hiCut);
m_phaseDiscri.setFMScaling(m_channelSampleRate / m_fmExcursion);
}
if ((settings.m_squelch != m_settings.m_squelch) || force) {
m_squelchLevel = std::pow(10.0, settings.m_squelch / 10.0);
}
m_settings = settings;
}