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sdrangel/plugins/channel/bfm/bfmdemod.cpp
2015-12-26 00:19:41 +01:00

425 lines
13 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2015 F4EXB //
// written by Edouard Griffiths //
// //
// 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 //
// //
// 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 <QTime>
#include <QDebug>
#include <stdio.h>
#include <complex.h>
#include "audio/audiooutput.h"
#include "dsp/dspengine.h"
#include "dsp/channelizer.h"
#include "dsp/pidcontroller.h"
#include "rdsparser.h"
#include "bfmdemod.h"
MESSAGE_CLASS_DEFINITION(BFMDemod::MsgConfigureBFMDemod, Message)
BFMDemod::BFMDemod(SampleSink* sampleSink, RDSParser *rdsParser) :
m_sampleSink(sampleSink),
m_rdsParser(rdsParser),
m_audioFifo(4, 250000),
m_settingsMutex(QMutex::Recursive),
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)
{
setObjectName("BFMDemod");
m_config.m_inputSampleRate = 384000;
m_config.m_inputFrequencyOffset = 0;
m_config.m_rfBandwidth = 180000;
m_config.m_afBandwidth = 15000;
m_config.m_squelch = -60.0;
m_config.m_volume = 2.0;
m_config.m_audioSampleRate = DSPEngine::instance()->getAudioSampleRate(); // normally 48 kHz
m_deemphasisFilterX.configure(default_deemphasis * m_config.m_audioSampleRate * 1.0e-6);
m_deemphasisFilterY.configure(default_deemphasis * m_config.m_audioSampleRate * 1.0e-6);
m_rfFilter = new fftfilt(-50000.0 / 384000.0, 50000.0 / 384000.0, filtFftLen);
m_phaseDiscri.setFMScaling(384000/m_fmExcursion);
apply();
m_audioBuffer.resize(16384);
m_audioBufferFill = 0;
m_movingAverage.resize(16, 0);
DSPEngine::instance()->addAudioSink(&m_audioFifo);
}
BFMDemod::~BFMDemod()
{
if (m_rfFilter)
{
delete m_rfFilter;
}
DSPEngine::instance()->removeAudioSink(&m_audioFifo);
}
void BFMDemod::configure(MessageQueue* messageQueue,
Real rfBandwidth,
Real afBandwidth,
Real volume,
Real squelch,
bool audioStereo,
bool lsbStereo,
bool showPilot,
bool rdsActive)
{
Message* cmd = MsgConfigureBFMDemod::create(rfBandwidth,
afBandwidth,
volume,
squelch,
audioStereo,
lsbStereo,
showPilot,
rdsActive);
messageQueue->push(cmd);
}
void BFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool firstOfBurst)
{
Complex ci, cs, cr;
fftfilt::cmplx *rf;
int rf_out;
Real msq, demod;
m_sampleBuffer.clear();
m_settingsMutex.lock();
for (SampleVector::const_iterator it = begin; it != end; ++it)
{
Complex c(it->real() / 32768.0f, it->imag() / 32768.0f);
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_movingAverage.feed(msq);
if(m_movingAverage.average() >= m_squelchLevel)
m_squelchState = m_running.m_rfBandwidth / 20; // decay rate
if(m_squelchState > 0)
{
m_squelchState--;
//demod = phaseDiscriminator2(rf[i], msq);
demod = m_phaseDiscri.phaseDiscriminator(rf[i]);
}
else
{
demod = 0;
}
if (!m_running.m_showPilot)
{
m_sampleBuffer.push_back(Sample(demod * (1<<15), 0.0));
}
if (m_running.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.interpolate(&m_interpolatorRDSDistanceRemain, r, &cr))
{
bool bit;
if (m_rdsDemod.process(cr.real(), bit))
{
if (m_rdsDecoder.frameSync(bit))
{
if (m_rdsParser)
{
m_rdsParser->parseGroup(m_rdsDecoder.getGroup());
}
}
}
m_interpolatorRDSDistanceRemain += m_interpolatorRDSDistance;
}
}
Real sampleStereo;
// Process stereo if stereo mode is selected
if (m_running.m_audioStereo)
{
m_pilotPLL.process(demod, m_pilotPLLSamples);
if (m_running.m_showPilot)
{
m_sampleBuffer.push_back(Sample(m_pilotPLLSamples[1] * (1<<15), 0.0)); // debug 38 kHz pilot
}
if (m_running.m_lsbStereo)
{
// 1.17 * 0.7 = 0.819
Complex s(demod * m_pilotPLLSamples[1], demod * m_pilotPLLSamples[2]);
if (m_interpolatorStereo.interpolate(&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.interpolate(&m_interpolatorStereoDistanceRemain, s, &cs))
{
sampleStereo = cs.real();
m_interpolatorStereoDistanceRemain += m_interpolatorStereoDistance;
}
}
}
Complex e(demod, 0);
if (m_interpolator.interpolate(&m_interpolatorDistanceRemain, e, &ci))
{
if (m_running.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);
if (m_running.m_lsbStereo)
{
m_audioBuffer[m_audioBufferFill].l = (qint16)(deemph_l * (1<<12) * m_running.m_volume);
m_audioBuffer[m_audioBufferFill].r = (qint16)(deemph_r * (1<<12) * m_running.m_volume);
}
else
{
m_audioBuffer[m_audioBufferFill].l = (qint16)(deemph_l * (1<<12) * m_running.m_volume);
m_audioBuffer[m_audioBufferFill].r = (qint16)(deemph_r * (1<<12) * m_running.m_volume);
}
}
else
{
Real deemph;
m_deemphasisFilterX.process(ci.real(), deemph);
quint16 sample = (qint16)(deemph * (1<<12) * m_running.m_volume);
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, 1);
if(res != m_audioBufferFill)
{
qDebug("BFMDemod::feed: %u/%u audio samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
}
m_interpolatorDistanceRemain += m_interpolatorDistance;
}
}
}
if(m_audioBufferFill > 0)
{
uint res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], m_audioBufferFill, 1);
if(res != m_audioBufferFill)
{
qDebug("BFMDemod::feed: %u/%u tail samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
}
if(m_sampleSink != 0)
{
m_sampleSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), true);
}
m_sampleBuffer.clear();
m_settingsMutex.unlock();
}
void BFMDemod::start()
{
m_squelchState = 0;
m_audioFifo.clear();
m_phaseDiscri.reset();
}
void BFMDemod::stop()
{
}
bool BFMDemod::handleMessage(const Message& cmd)
{
if (Channelizer::MsgChannelizerNotification::match(cmd))
{
Channelizer::MsgChannelizerNotification& notif = (Channelizer::MsgChannelizerNotification&) cmd;
m_config.m_inputSampleRate = notif.getSampleRate();
m_config.m_inputFrequencyOffset = notif.getFrequencyOffset();
apply();
qDebug() << "BFMDemod::handleMessage: MsgChannelizerNotification: m_inputSampleRate: " << m_config.m_inputSampleRate
<< " m_inputFrequencyOffset: " << m_config.m_inputFrequencyOffset;
return true;
}
else if (MsgConfigureBFMDemod::match(cmd))
{
MsgConfigureBFMDemod& cfg = (MsgConfigureBFMDemod&) cmd;
m_config.m_rfBandwidth = cfg.getRFBandwidth();
m_config.m_afBandwidth = cfg.getAFBandwidth();
m_config.m_volume = cfg.getVolume();
m_config.m_squelch = cfg.getSquelch();
m_config.m_audioStereo = cfg.getAudioStereo();
m_config.m_lsbStereo = cfg.getLsbStereo();
m_config.m_showPilot = cfg.getShowPilot();
m_config.m_rdsActive = cfg.getRDSActive();
apply();
qDebug() << "BFMDemod::handleMessage: MsgConfigureBFMDemod: m_rfBandwidth: " << m_config.m_rfBandwidth
<< " m_afBandwidth: " << m_config.m_afBandwidth
<< " m_volume: " << m_config.m_volume
<< " m_squelch: " << m_config.m_squelch
<< " m_audioStereo: " << m_config.m_audioStereo
<< " m_lsbStereo: " << m_config.m_lsbStereo
<< " m_showPilot: " << m_config.m_showPilot
<< " m_rdsActive: " << m_config.m_rdsActive;
return true;
}
else
{
qDebug() << "BFMDemod::handleMessage: none";
if (m_sampleSink != 0)
{
return m_sampleSink->handleMessage(cmd);
}
else
{
return false;
}
}
}
void BFMDemod::apply()
{
if ((m_config.m_inputSampleRate != m_running.m_inputSampleRate)
|| (m_config.m_audioStereo && (m_config.m_audioStereo != m_running.m_audioStereo)))
{
m_pilotPLL.configure(19000.0/m_config.m_inputSampleRate, 50.0/m_config.m_inputSampleRate, 0.01);
}
if((m_config.m_inputFrequencyOffset != m_running.m_inputFrequencyOffset) ||
(m_config.m_inputSampleRate != m_running.m_inputSampleRate))
{
qDebug() << "BFMDemod::handleMessage: m_nco.setFreq";
m_nco.setFreq(-m_config.m_inputFrequencyOffset, m_config.m_inputSampleRate);
}
if((m_config.m_inputSampleRate != m_running.m_inputSampleRate) ||
(m_config.m_afBandwidth != m_running.m_afBandwidth))
{
m_settingsMutex.lock();
qDebug() << "BFMDemod::handleMessage: m_interpolator.create";
m_interpolator.create(16, m_config.m_inputSampleRate, m_config.m_afBandwidth);
m_interpolatorDistanceRemain = (Real) m_config.m_inputSampleRate / m_config.m_audioSampleRate;
m_interpolatorDistance = (Real) m_config.m_inputSampleRate / (Real) m_config.m_audioSampleRate;
m_interpolatorStereo.create(16, m_config.m_inputSampleRate, m_config.m_afBandwidth);
m_interpolatorStereoDistanceRemain = (Real) m_config.m_inputSampleRate / m_config.m_audioSampleRate;
m_interpolatorStereoDistance = (Real) m_config.m_inputSampleRate / (Real) m_config.m_audioSampleRate;
m_interpolatorRDS.create(4, m_config.m_inputSampleRate, 600.0);
m_interpolatorRDSDistanceRemain = (Real) m_config.m_inputSampleRate / 250000.0;
m_interpolatorRDSDistance = (Real) m_config.m_inputSampleRate / 250000.0;
m_settingsMutex.unlock();
}
if((m_config.m_inputSampleRate != m_running.m_inputSampleRate) ||
(m_config.m_rfBandwidth != m_running.m_rfBandwidth) ||
(m_config.m_inputFrequencyOffset != m_running.m_inputFrequencyOffset))
{
m_settingsMutex.lock();
Real lowCut = -(m_config.m_rfBandwidth / 2.0) / m_config.m_inputSampleRate;
Real hiCut = (m_config.m_rfBandwidth / 2.0) / m_config.m_inputSampleRate;
m_rfFilter->create_filter(lowCut, hiCut);
m_phaseDiscri.setFMScaling(m_config.m_inputSampleRate / m_fmExcursion);
m_settingsMutex.unlock();
qDebug() << "BFMDemod::handleMessage: m_rfFilter->create_filter: sampleRate: "
<< m_config.m_inputSampleRate
<< " lowCut: " << lowCut * m_config.m_inputSampleRate
<< " hiCut: " << hiCut * m_config.m_inputSampleRate;
}
if((m_config.m_afBandwidth != m_running.m_afBandwidth) ||
(m_config.m_audioSampleRate != m_running.m_audioSampleRate))
{
m_settingsMutex.lock();
qDebug() << "BFMDemod::handleMessage: m_lowpass.create";
m_lowpass.create(21, m_config.m_audioSampleRate, m_config.m_afBandwidth);
m_settingsMutex.unlock();
}
if(m_config.m_squelch != m_running.m_squelch) {
qDebug() << "BFMDemod::handleMessage: set m_squelchLevel";
m_squelchLevel = std::pow(10.0, m_config.m_squelch / 20.0);
m_squelchLevel *= m_squelchLevel;
}
if (m_config.m_audioSampleRate != m_running.m_audioSampleRate)
{
m_deemphasisFilterX.configure(default_deemphasis * m_config.m_audioSampleRate * 1.0e-6);
m_deemphasisFilterY.configure(default_deemphasis * m_config.m_audioSampleRate * 1.0e-6);
}
m_running.m_inputSampleRate = m_config.m_inputSampleRate;
m_running.m_inputFrequencyOffset = m_config.m_inputFrequencyOffset;
m_running.m_rfBandwidth = m_config.m_rfBandwidth;
m_running.m_afBandwidth = m_config.m_afBandwidth;
m_running.m_squelch = m_config.m_squelch;
m_running.m_volume = m_config.m_volume;
m_running.m_audioSampleRate = m_config.m_audioSampleRate;
m_running.m_audioStereo = m_config.m_audioStereo;
m_running.m_lsbStereo = m_config.m_lsbStereo;
m_running.m_showPilot = m_config.m_showPilot;
m_running.m_rdsActive = m_config.m_rdsActive;
}