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sdrangel/plugins/channel/am/amdemod.cpp
2015-10-05 00:54:14 +02:00

259 lines
7.2 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2015 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 //
// //
// 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 "amdemod.h"
#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"
MESSAGE_CLASS_DEFINITION(AMDemod::MsgConfigureAMDemod, Message)
AMDemod::AMDemod() :
m_audioFifo(4, 48000),
m_settingsMutex(QMutex::Recursive)
{
setObjectName("AMDemod");
m_config.m_inputSampleRate = 96000;
m_config.m_inputFrequencyOffset = 0;
m_config.m_rfBandwidth = 12500;
m_config.m_afBandwidth = 3000;
m_config.m_squelch = -40.0;
m_config.m_volume = 2.0;
m_config.m_audioSampleRate = DSPEngine::instance()->getAudioSampleRate();
apply();
m_audioBuffer.resize(1<<14);
m_audioBufferFill = 0;
m_movingAverage.resize(16, 0);
m_volumeAGC.resize(4096, 0.003, 0);
m_magsq = 0.0;
DSPEngine::instance()->addAudioSink(&m_audioFifo);
}
AMDemod::~AMDemod()
{
DSPEngine::instance()->removeAudioSink(&m_audioFifo);
}
void AMDemod::configure(MessageQueue* messageQueue, Real rfBandwidth, Real afBandwidth, Real volume, Real squelch)
{
Message* cmd = MsgConfigureAMDemod::create(rfBandwidth, afBandwidth, volume, squelch);
messageQueue->push(cmd);
}
void AMDemod::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool firstOfBurst)
{
Complex ci;
m_settingsMutex.lock();
for (SampleVector::const_iterator it = begin; it != end; ++it)
{
//Complex c(it->real() / 32768.0, it->imag() / 32768.0);
Complex c(it->real(), it->imag());
c *= m_nco.nextIQ();
if (m_interpolator.interpolate(&m_interpolatorDistanceRemain, c, &ci))
{
//m_sampleBuffer.push_back(Sample(ci.real() * 32767.0, ci.imag() * 32767.0));
m_sampleBuffer.push_back(Sample(ci.real(), ci.imag()));
Real magsq = ci.real() * ci.real() + ci.imag() * ci.imag();
magsq /= (1<<30);
m_movingAverage.feed(magsq);
m_magsq = m_movingAverage.average();
if (m_magsq >= m_squelchLevel)
{
m_squelchState = m_running.m_audioSampleRate / 20;
}
qint16 sample;
if (m_squelchState > 0)
{
m_squelchState--;
Real demod = sqrt(magsq);
demod = m_lowpass.filter(demod);
if (demod < -1)
{
demod = -1;
}
else if (demod > 1)
{
demod = 1;
}
m_volumeAGC.feed(demod);
demod *= (0.003 / m_volumeAGC.getValue());
demod *= m_running.m_volume;
sample = demod * 32700 * 16;
}
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, 10);
if (res != m_audioBufferFill)
{
qDebug("AMDemod::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, 10);
if (res != m_audioBufferFill)
{
qDebug("AMDemod::feed: %u/%u tail samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
}
m_sampleBuffer.clear();
m_settingsMutex.unlock();
}
void AMDemod::start()
{
qDebug() << "AMDemod::start: m_inputSampleRate: " << m_config.m_inputSampleRate
<< " m_inputFrequencyOffset: " << m_config.m_inputFrequencyOffset;
m_squelchState = 0;
m_audioFifo.clear();
}
void AMDemod::stop()
{
}
bool AMDemod::handleMessage(const Message& cmd)
{
qDebug() << "AMDemod::handleMessage";
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() << "AMDemod::handleMessage: MsgChannelizerNotification:"
<< " m_inputSampleRate: " << m_config.m_inputSampleRate
<< " m_inputFrequencyOffset: " << m_config.m_inputFrequencyOffset;
return true;
}
else if (MsgConfigureAMDemod::match(cmd))
{
MsgConfigureAMDemod& cfg = (MsgConfigureAMDemod&) 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();
apply();
qDebug() << "AMDemod::handleMessage: MsgConfigureAMDemod:"
<< " m_rfBandwidth: " << m_config.m_rfBandwidth
<< " m_afBandwidth: " << m_config.m_afBandwidth
<< " m_volume: " << m_config.m_volume
<< " m_squelch: " << m_config.m_squelch;
return true;
}
else
{
return false;
}
}
void AMDemod::apply()
{
if((m_config.m_inputFrequencyOffset != m_running.m_inputFrequencyOffset) ||
(m_config.m_inputSampleRate != m_running.m_inputSampleRate))
{
m_nco.setFreq(-m_config.m_inputFrequencyOffset, m_config.m_inputSampleRate);
}
if((m_config.m_inputSampleRate != m_running.m_inputSampleRate) ||
(m_config.m_rfBandwidth != m_running.m_rfBandwidth))
{
m_settingsMutex.lock();
m_interpolator.create(16, m_config.m_inputSampleRate, m_config.m_rfBandwidth / 2.2);
m_interpolatorDistanceRemain = 0;
m_interpolatorDistance = (Real) m_config.m_inputSampleRate / (Real) m_config.m_audioSampleRate;
m_settingsMutex.unlock();
}
if((m_config.m_afBandwidth != m_running.m_afBandwidth) ||
(m_config.m_audioSampleRate != m_running.m_audioSampleRate))
{
m_settingsMutex.lock();
m_lowpass.create(21, m_config.m_audioSampleRate, m_config.m_afBandwidth);
m_settingsMutex.unlock();
}
if(m_config.m_squelch != m_running.m_squelch)
{
m_squelchLevel = pow(10.0, m_config.m_squelch / 20.0);
m_squelchLevel *= m_squelchLevel;
}
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;
}