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sdrangel/plugins/channelrx/demodssb/ssbdemodsink.cpp

401 lines
14 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019 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 //
// (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 "audio/audiooutput.h"
#include "dsp/dspengine.h"
#include "dsp/dspcommands.h"
#include "dsp/devicesamplemimo.h"
#include "dsp/basebandsamplesink.h"
#include "device/deviceapi.h"
#include "util/db.h"
#include "ssbdemodsink.h"
const int SSBDemodSink::m_ssbFftLen = 1024;
const int SSBDemodSink::m_agcTarget = 3276; // 32768/10 -10 dB amplitude => -20 dB power: center of normal signal
SSBDemodSink::SSBDemodSink() :
m_audioBinaual(false),
m_audioFlipChannels(false),
m_dsb(false),
m_audioMute(false),
m_agc(12000, m_agcTarget, 1e-2),
m_agcActive(false),
m_agcClamping(false),
m_agcNbSamples(12000),
m_agcPowerThreshold(1e-2),
m_agcThresholdGate(0),
m_squelchDelayLine(2*48000),
m_audioActive(false),
m_spectrumSink(nullptr),
m_audioFifo(24000),
m_audioSampleRate(48000)
{
m_Bandwidth = 5000;
m_LowCutoff = 300;
m_volume = 2.0;
m_spanLog2 = 3;
m_channelSampleRate = 48000;
m_channelFrequencyOffset = 0;
m_audioBuffer.resize(1<<14);
m_audioBufferFill = 0;
m_undersampleCount = 0;
m_sum = 0;
m_usb = true;
m_magsq = 0.0f;
m_magsqSum = 0.0f;
m_magsqPeak = 0.0f;
m_magsqCount = 0;
m_agc.setClampMax(SDR_RX_SCALED/100.0);
m_agc.setClamping(m_agcClamping);
SSBFilter = new fftfilt(m_LowCutoff / m_audioSampleRate, m_Bandwidth / m_audioSampleRate, m_ssbFftLen);
DSBFilter = new fftfilt((2.0f * m_Bandwidth) / m_audioSampleRate, 2 * m_ssbFftLen);
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
applySettings(m_settings, true);
}
SSBDemodSink::~SSBDemodSink()
{
delete SSBFilter;
delete DSBFilter;
}
void SSBDemodSink::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
{
if (m_interpolator.decimate(&m_interpolatorDistanceRemain, c, &ci))
{
processOneSample(ci);
m_interpolatorDistanceRemain += m_interpolatorDistance;
}
}
}
}
void SSBDemodSink::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)
if (m_dsb) {
n_out = DSBFilter->runDSB(ci, &sideband);
} else {
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++;
if (!m_dsb & !m_usb)
{ // invert spectrum for LSB
m_sampleBuffer.push_back(Sample(avgi, avgr));
}
else
{
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& delayedSample = m_squelchDelayLine.readBack(m_agc.getStepDownDelay());
m_audioActive = delayedSample.real() != 0.0;
m_squelchDelayLine.write(sideband[i]*agcVal);
if (m_audioMute)
{
m_audioBuffer[m_audioBufferFill].r = 0;
m_audioBuffer[m_audioBufferFill].l = 0;
}
else
{
fftfilt::cmplx z = m_agcActive ? delayedSample * m_agc.getStepValue() : delayedSample;
if (m_audioBinaual)
{
if (m_audioFlipChannels)
{
m_audioBuffer[m_audioBufferFill].r = (qint16)(z.imag() * m_volume);
m_audioBuffer[m_audioBufferFill].l = (qint16)(z.real() * m_volume);
}
else
{
m_audioBuffer[m_audioBufferFill].r = (qint16)(z.real() * m_volume);
m_audioBuffer[m_audioBufferFill].l = (qint16)(z.imag() * m_volume);
}
}
else
{
Real demod = (z.real() + z.imag()) * 0.7;
qint16 sample = (qint16)(demod * 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);
if (res != m_audioBufferFill) {
qDebug("SSBDemodSink::feed: %u/%u samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
}
}
uint res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], m_audioBufferFill);
if (res != m_audioBufferFill) {
qDebug("SSBDemodSink::feed: %u/%u tail samples written", res, m_audioBufferFill);
}
m_audioBufferFill = 0;
if (m_spectrumSink != 0) {
m_spectrumSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), !m_dsb);
}
m_sampleBuffer.clear();
}
void SSBDemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
{
qDebug() << "SSBDemodSink::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) m_audioSampleRate;
}
m_channelSampleRate = channelSampleRate;
m_channelFrequencyOffset = channelFrequencyOffset;
}
void SSBDemodSink::applyAudioSampleRate(int sampleRate)
{
qDebug("SSBDemodSink::applyAudioSampleRate: %d", sampleRate);
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) sampleRate;
SSBFilter->create_filter(m_LowCutoff / (float) sampleRate, m_Bandwidth / (float) sampleRate);
DSBFilter->create_dsb_filter((2.0f * m_Bandwidth) / (float) sampleRate);
int agcNbSamples = (sampleRate / 1000) * (1<<m_settings.m_agcTimeLog2);
int agcThresholdGate = (sampleRate / 1000) * m_settings.m_agcThresholdGate; // ms
if (m_agcNbSamples != agcNbSamples)
{
m_agc.resize(agcNbSamples, agcNbSamples/2, m_agcTarget);
m_agc.setStepDownDelay(agcNbSamples);
m_agcNbSamples = agcNbSamples;
}
if (m_agcThresholdGate != agcThresholdGate)
{
m_agc.setGate(agcThresholdGate);
m_agcThresholdGate = agcThresholdGate;
}
m_audioFifo.setSize(sampleRate);
m_audioSampleRate = sampleRate;
}
void SSBDemodSink::applySettings(const SSBDemodSettings& settings, bool force)
{
qDebug() << "SSBDemodSink::applySettings:"
<< " m_inputFrequencyOffset: " << settings.m_inputFrequencyOffset
<< " m_rfBandwidth: " << settings.m_rfBandwidth
<< " m_lowCutoff: " << settings.m_lowCutoff
<< " m_volume: " << settings.m_volume
<< " m_spanLog2: " << settings.m_spanLog2
<< " m_audioBinaual: " << settings.m_audioBinaural
<< " m_audioFlipChannels: " << settings.m_audioFlipChannels
<< " m_dsb: " << settings.m_dsb
<< " m_audioMute: " << settings.m_audioMute
<< " m_agcActive: " << settings.m_agc
<< " m_agcClamping: " << settings.m_agcClamping
<< " m_agcTimeLog2: " << settings.m_agcTimeLog2
<< " agcPowerThreshold: " << settings.m_agcPowerThreshold
<< " agcThresholdGate: " << settings.m_agcThresholdGate
<< " m_audioDeviceName: " << settings.m_audioDeviceName
<< " 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_rfBandwidth != settings.m_rfBandwidth) ||
(m_settings.m_lowCutoff != settings.m_lowCutoff) || force)
{
float band, lowCutoff;
band = settings.m_rfBandwidth;
lowCutoff = settings.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) m_audioSampleRate;
SSBFilter->create_filter(m_LowCutoff / (float) m_audioSampleRate, m_Bandwidth / (float) m_audioSampleRate);
DSBFilter->create_dsb_filter((2.0f * m_Bandwidth) / (float) m_audioSampleRate);
}
if ((m_settings.m_volume != settings.m_volume) || force)
{
m_volume = settings.m_volume;
m_volume /= 4.0; // for 3276.8
}
if ((m_settings.m_agcTimeLog2 != settings.m_agcTimeLog2) ||
(m_settings.m_agcPowerThreshold != settings.m_agcPowerThreshold) ||
(m_settings.m_agcThresholdGate != settings.m_agcThresholdGate) ||
(m_settings.m_agcClamping != settings.m_agcClamping) || force)
{
int agcNbSamples = (m_audioSampleRate / 1000) * (1<<settings.m_agcTimeLog2);
m_agc.setThresholdEnable(settings.m_agcPowerThreshold != -SSBDemodSettings::m_minPowerThresholdDB);
double agcPowerThreshold = CalcDb::powerFromdB(settings.m_agcPowerThreshold) * (SDR_RX_SCALED*SDR_RX_SCALED);
int agcThresholdGate = (m_audioSampleRate / 1000) * settings.m_agcThresholdGate; // ms
bool agcClamping = settings.m_agcClamping;
if (m_agcNbSamples != agcNbSamples)
{
m_agc.resize(agcNbSamples, agcNbSamples/2, m_agcTarget);
m_agc.setStepDownDelay(agcNbSamples);
m_agcNbSamples = agcNbSamples;
}
if (m_agcPowerThreshold != agcPowerThreshold)
{
m_agc.setThreshold(agcPowerThreshold);
m_agcPowerThreshold = agcPowerThreshold;
}
if (m_agcThresholdGate != agcThresholdGate)
{
m_agc.setGate(agcThresholdGate);
m_agcThresholdGate = agcThresholdGate;
}
if (m_agcClamping != agcClamping)
{
m_agc.setClamping(agcClamping);
m_agcClamping = agcClamping;
}
qDebug() << "SBDemodSink::applySettings: AGC:"
<< " agcNbSamples: " << agcNbSamples
<< " agcPowerThreshold: " << agcPowerThreshold
<< " agcThresholdGate: " << agcThresholdGate
<< " agcClamping: " << agcClamping;
}
m_spanLog2 = settings.m_spanLog2;
m_audioBinaual = settings.m_audioBinaural;
m_audioFlipChannels = settings.m_audioFlipChannels;
m_dsb = settings.m_dsb;
m_audioMute = settings.m_audioMute;
m_agcActive = settings.m_agc;
m_settings = settings;
}