/////////////////////////////////////////////////////////////////////////////////// // 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 . // /////////////////////////////////////////////////////////////////////////////////// #include #include #include "audio/audiooutputdevice.h" #include "dsp/fftfilt.h" #include "util/db.h" #include "util/stepfunctions.h" #include "amdemodsink.h" AMDemodSink::AMDemodSink() : m_channelSampleRate(48000), m_audioSampleRate(48000), m_channelFrequencyOffset(0), m_squelchCount(0), m_squelchOpen(false), m_squelchDelayLine(9600), m_magsqSum(0.0f), m_magsqPeak(0.0f), m_magsqCount(0), m_volumeAGC(0.003), m_syncAMAGC(12000, 0.1, 1e-2), m_audioFifo(48000) { m_audioBuffer.resize(1<<14); m_audioBufferFill = 0; m_magsq = 0.0; DSBFilter = new fftfilt((2.0f * m_settings.m_rfBandwidth) / m_audioSampleRate, 2 * 1024); SSBFilter = new fftfilt(0.0f, m_settings.m_rfBandwidth / m_audioSampleRate, 1024); m_syncAMAGC.setThresholdEnable(false); m_syncAMAGC.resize(12000, 6000, 0.1); m_pllFilt.create(101, m_audioSampleRate, 200.0); m_pll.computeCoefficients(0.05, 0.707, 1000); m_syncAMBuffIndex = 0; applySettings(m_settings, true); applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true); } AMDemodSink::~AMDemodSink() { delete DSBFilter; delete SSBFilter; } void AMDemodSink::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; } } } if (m_audioBufferFill > 0) { uint res = m_audioFifo.write((const quint8*)&m_audioBuffer[0], m_audioBufferFill); if (res != m_audioBufferFill) { qDebug("AMDemodSink::feed: %u/%u tail samples written", res, m_audioBufferFill); } m_audioBufferFill = 0; } } void AMDemodSink::processOneSample(Complex &ci) { Real re = ci.real() / SDR_RX_SCALEF; Real im = ci.imag() / SDR_RX_SCALEF; Real magsq = re*re + im*im; m_movingAverage(magsq); m_magsq = m_movingAverage.asDouble(); m_magsqSum += magsq; if (magsq > m_magsqPeak) { m_magsqPeak = magsq; } m_magsqCount++; m_squelchDelayLine.write(magsq); if (m_magsq < m_squelchLevel) { if (m_squelchCount > 0) { m_squelchCount--; } } else { if (m_squelchCount < m_audioSampleRate / 10) { m_squelchCount++; } } qint16 sample; m_squelchOpen = (m_squelchCount >= m_audioSampleRate / 20); if (m_squelchOpen && !m_settings.m_audioMute) { Real demod; if (m_settings.m_pll) { std::complex s(re, im); s = m_pllFilt.filter(s); m_pll.feed(s.real(), s.imag()); float yr = re * m_pll.getImag() - im * m_pll.getReal(); float yi = re * m_pll.getReal() + im * m_pll.getImag(); fftfilt::cmplx *sideband; std::complex cs(yr, yi); int n_out; if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMDSB) { n_out = DSBFilter->runDSB(cs, &sideband, false); } else { n_out = SSBFilter->runSSB(cs, &sideband, m_settings.m_syncAMOperation == AMDemodSettings::SyncAMUSB, false); } for (int i = 0; i < n_out; i++) { float agcVal = m_syncAMAGC.feedAndGetValue(sideband[i]); fftfilt::cmplx z = sideband[i] * agcVal; // * m_syncAMAGC.getStepValue(); if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMDSB) { m_syncAMBuff[i] = (z.real() + z.imag()); } else if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMUSB) { m_syncAMBuff[i] = (z.real() + z.imag()); } else { m_syncAMBuff[i] = (z.real() + z.imag()); } m_syncAMBuffIndex = 0; } m_syncAMBuffIndex = m_syncAMBuffIndex < 2*1024 ? m_syncAMBuffIndex : 0; demod = m_syncAMBuff[m_syncAMBuffIndex++]*4.0f; // mos pifometrico } else { demod = sqrt(m_squelchDelayLine.readBack(m_audioSampleRate/20)); m_volumeAGC.feed(demod); demod = (demod - m_volumeAGC.getValue()) / m_volumeAGC.getValue(); } if (m_settings.m_bandpassEnable) { demod = m_bandpass.filter(demod); } else { demod = m_lowpass.filter(demod); } Real attack = (m_squelchCount - 0.05f * m_audioSampleRate) / (0.05f * m_audioSampleRate); sample = demod * StepFunctions::smootherstep(attack) * (m_audioSampleRate/24) * m_settings.m_volume; } 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); if (res != m_audioBufferFill) { qDebug("AMDemodSink::processOneSample: %u/%u audio samples written", res, m_audioBufferFill); m_audioFifo.clear(); } m_audioBufferFill = 0; } } void AMDemodSink::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force) { qDebug() << "AMDemodSink::applyChannelSettings:" << " channelSampleRate: " << channelSampleRate << " channelFrequencyOffset: " << channelFrequencyOffset << " m_audioSampleRate: " << m_audioSampleRate; 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 / 2.2f); m_interpolatorDistanceRemain = 0; m_interpolatorDistance = (Real) channelSampleRate / (Real) m_audioSampleRate; } m_channelSampleRate = channelSampleRate; m_channelFrequencyOffset = channelFrequencyOffset; } void AMDemodSink::applySettings(const AMDemodSettings& settings, bool force) { qDebug() << "AMDemodSink::applySettings:" << " m_inputFrequencyOffset: " << settings.m_inputFrequencyOffset << " m_rfBandwidth: " << settings.m_rfBandwidth << " m_volume: " << settings.m_volume << " m_squelch: " << settings.m_squelch << " m_audioMute: " << settings.m_audioMute << " m_bandpassEnable: " << settings.m_bandpassEnable << " m_audioDeviceName: " << settings.m_audioDeviceName << " m_pll: " << settings.m_pll << " m_syncAMOperation: " << (int) settings.m_syncAMOperation << " force: " << force; if((m_settings.m_rfBandwidth != settings.m_rfBandwidth) || (m_settings.m_bandpassEnable != settings.m_bandpassEnable) || force) { m_interpolator.create(16, m_channelSampleRate, settings.m_rfBandwidth / 2.2f); m_interpolatorDistanceRemain = 0; m_interpolatorDistance = (Real) m_channelSampleRate / (Real) m_audioSampleRate; m_bandpass.create(301, m_audioSampleRate, 300.0, settings.m_rfBandwidth / 2.0f); m_lowpass.create(301, m_audioSampleRate, settings.m_rfBandwidth / 2.0f); DSBFilter->create_dsb_filter((2.0f * settings.m_rfBandwidth) / (float) m_audioSampleRate); } if ((m_settings.m_squelch != settings.m_squelch) || force) { m_squelchLevel = CalcDb::powerFromdB(settings.m_squelch); } if ((m_settings.m_pll != settings.m_pll) || force) { if (settings.m_pll) { m_volumeAGC.resizeNew(m_audioSampleRate/4, 0.003); m_syncAMBuffIndex = 0; } else { m_volumeAGC.resizeNew(m_audioSampleRate/10, 0.003); } } if ((m_settings.m_syncAMOperation != settings.m_syncAMOperation) || force) { m_syncAMBuffIndex = 0; } m_settings = settings; } void AMDemodSink::applyAudioSampleRate(int sampleRate) { if (sampleRate < 0) { qWarning("AMDemodSink::applyAudioSampleRate: invalid sample rate: %d", sampleRate); return; } qDebug("AMDemodSink::applyAudioSampleRate: sampleRate: %d m_channelSampleRate: %d", sampleRate, m_channelSampleRate); m_interpolator.create(16, m_channelSampleRate, m_settings.m_rfBandwidth / 2.2f); m_interpolatorDistanceRemain = 0; m_interpolatorDistance = (Real) m_channelSampleRate / (Real) sampleRate; m_bandpass.create(301, sampleRate, 300.0, m_settings.m_rfBandwidth / 2.0f); m_lowpass.create(301, sampleRate, m_settings.m_rfBandwidth / 2.0f); m_audioFifo.setSize(sampleRate); m_squelchDelayLine.resize(sampleRate/5); DSBFilter->create_dsb_filter((2.0f * m_settings.m_rfBandwidth) / (float) sampleRate); m_pllFilt.create(101, sampleRate, 200.0); if (m_settings.m_pll) { m_volumeAGC.resizeNew(sampleRate, 0.003); } else { m_volumeAGC.resizeNew(sampleRate/10, 0.003); } m_syncAMAGC.resize(sampleRate/4, sampleRate/8, 0.1); m_pll.setSampleRate(sampleRate); m_audioSampleRate = sampleRate; }