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			337 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			337 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| ///////////////////////////////////////////////////////////////////////////////////
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| // Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
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| // written by Christian Daniel                                                   //
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| // Copyright (C) 2015-2020, 2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com>    //
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| // Copyright (C) 2023 Jon Beniston, M7RCE <jon@beniston.com>                     //
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| //                                                                               //
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| // This program is free software; you can redistribute it and/or modify          //
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| // it under the terms of the GNU General Public License as published by          //
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| // the Free Software Foundation as version 3 of the License, or                  //
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| // (at your option) any later version.                                           //
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| //                                                                               //
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| // This program is distributed in the hope that it will be useful,               //
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| // but WITHOUT ANY WARRANTY; without even the implied warranty of                //
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| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                  //
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| // GNU General Public License V3 for more details.                               //
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| //                                                                               //
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| // You should have received a copy of the GNU General Public License             //
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| // along with this program. If not, see <http://www.gnu.org/licenses/>.          //
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| ///////////////////////////////////////////////////////////////////////////////////
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| 
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| #include <array>
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| 
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| #include <QString>
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| #include <QDebug>
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| 
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| #include "dsp/hbfilterchainconverter.h"
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| #include "downchannelizer.h"
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| 
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| DownChannelizer::DownChannelizer(ChannelSampleSink* sampleSink) :
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|     m_filterChainSetMode(false),
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| 	m_sampleSink(sampleSink),
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| 	m_basebandSampleRate(0),
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| 	m_requestedOutputSampleRate(0),
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| 	m_requestedCenterFrequency(0),
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|     m_channelSampleRate(0),
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| 	m_channelFrequencyOffset(0),
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|     m_log2Decim(0),
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|     m_filterChainHash(0)
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| {
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| }
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| 
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| DownChannelizer::~DownChannelizer()
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| {
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| 	freeFilterChain();
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| }
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| 
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| void DownChannelizer::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end)
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| {
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| 	if (m_sampleSink == 0)
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|     {
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| 		m_sampleBuffer.clear();
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| 		return;
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| 	}
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| 
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| 	if (m_filterStages.size() == 0) // optimization when no downsampling is done anyway
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| 	{
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| 		m_sampleSink->feed(begin, end);
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| 	}
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| 	else
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| 	{
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| 		for (SampleVector::const_iterator sample = begin; sample != end; ++sample)
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| 		{
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| 			Sample s(*sample);
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| 			FilterStages::iterator stage = m_filterStages.begin();
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| 
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| 			for (; stage != m_filterStages.end(); ++stage)
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| 			{
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| #ifndef SDR_RX_SAMPLE_24BIT
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|                 s.m_real /= 2; // avoid saturation on 16 bit samples
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|                 s.m_imag /= 2;
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| #endif
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| 				if (!(*stage)->work(&s)) {
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| 					break;
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| 				}
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| 			}
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| 
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| 			if(stage == m_filterStages.end())
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| 			{
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| #ifdef SDR_RX_SAMPLE_24BIT
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| 			    s.m_real /= (1<<(m_filterStages.size())); // on 32 bit samples there is enough headroom to just divide the final result
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| 			    s.m_imag /= (1<<(m_filterStages.size()));
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| #endif
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| 				m_sampleBuffer.push_back(s);
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| 			}
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| 		}
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| 
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| 		m_sampleSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end());
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| 		m_sampleBuffer.clear();
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| 	}
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| }
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| 
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| void DownChannelizer::setChannelization(int requestedSampleRate, qint64 requestedCenterFrequency)
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| {
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|     if (requestedSampleRate < 0)
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|     {
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|         qWarning("DownChannelizer::setChannelization: wrong sample rate requested: %d", requestedSampleRate);
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|         return;
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|     }
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| 
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|     m_requestedOutputSampleRate = requestedSampleRate;
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|     m_requestedCenterFrequency = requestedCenterFrequency;
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|     applyChannelization();
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| }
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| 
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| void DownChannelizer::setBasebandSampleRate(int basebandSampleRate, bool decim)
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| {
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|     m_basebandSampleRate = basebandSampleRate;
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| 
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|     if (decim) {
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|         applyDecimation();
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|     } else {
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|         applyChannelization();
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|     }
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| }
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| 
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| void DownChannelizer::applyChannelization()
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| {
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|     m_filterChainSetMode = false;
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| 
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| 	if (m_basebandSampleRate == 0)
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| 	{
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| 		qDebug() << "DownChannelizer::applyChannelization: aborting (in=0)"
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|             << " in (baseband):" << m_basebandSampleRate
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|             << " req:" << m_requestedOutputSampleRate
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|             << " out (channel):" << m_channelSampleRate
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|             << " fc:" << m_channelFrequencyOffset;
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|         return;
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| 	}
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| 
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| 	freeFilterChain();
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| 
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| 	m_channelFrequencyOffset = createFilterChain(
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| 		m_basebandSampleRate / -2, m_basebandSampleRate / 2,
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| 		m_requestedCenterFrequency - m_requestedOutputSampleRate / 2, m_requestedCenterFrequency + m_requestedOutputSampleRate / 2);
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| 
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| 	m_channelSampleRate = m_basebandSampleRate / (1 << m_filterStages.size());
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| 
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| 	qDebug() << "DownChannelizer::applyChannelization done:"
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|         << " nb stages:" << m_filterStages.size()
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|         << " in (baseband):" << m_basebandSampleRate
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| 		<< " req:" << m_requestedOutputSampleRate
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| 		<< " out (channel):" << m_channelSampleRate
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| 		<< " fc:" << m_channelFrequencyOffset;
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| }
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| 
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| void DownChannelizer::setDecimation(unsigned int log2Decim, unsigned int filterChainHash)
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| {
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|     m_log2Decim = log2Decim;
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|     m_filterChainHash = filterChainHash;
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|     applyDecimation();
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| }
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| 
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| void DownChannelizer::applyDecimation()
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| {
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|     m_filterChainSetMode = true;
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|     std::vector<unsigned int> stageIndexes;
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|     m_channelFrequencyOffset = m_basebandSampleRate * HBFilterChainConverter::convertToIndexes(m_log2Decim, m_filterChainHash, stageIndexes);
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|     m_requestedCenterFrequency = m_channelFrequencyOffset;
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| 
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|     freeFilterChain();
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| 
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|     m_channelFrequencyOffset = m_basebandSampleRate * setFilterChain(stageIndexes);
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|     m_channelSampleRate = m_basebandSampleRate / (1 << m_filterStages.size());
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|     m_requestedOutputSampleRate = m_channelSampleRate;
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| 
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| 	qDebug() << "DownChannelizer::applyDecimation:"
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|             << " m_log2Decim:" << m_log2Decim
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|             << " m_filterChainHash:" << m_filterChainHash
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|             << " out:" << m_basebandSampleRate
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| 			<< " in:" << m_channelSampleRate
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| 			<< " fc:" << m_channelFrequencyOffset;
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| }
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| 
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| #ifdef SDR_RX_SAMPLE_24BIT
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| DownChannelizer::FilterStage::FilterStage(Mode mode) :
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|     m_filter(new IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>),
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|     m_workFunction(0),
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|     m_mode(mode),
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|     m_sse(true)
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| {
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|     switch(mode) {
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|         case ModeCenter:
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|             m_workFunction = &IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateCenter;
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|             break;
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| 
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|         case ModeLowerHalf:
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|             m_workFunction = &IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateLowerHalf;
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|             break;
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| 
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|         case ModeUpperHalf:
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|             m_workFunction = &IntHalfbandFilterEO<qint64, qint64, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateUpperHalf;
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|             break;
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|     }
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| }
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| #else
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| DownChannelizer::FilterStage::FilterStage(Mode mode) :
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|     m_filter(new IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>),
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|     m_workFunction(0),
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|     m_mode(mode),
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|     m_sse(true)
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| {
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|     switch(mode) {
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|         case ModeCenter:
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|             m_workFunction = &IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateCenter;
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|             break;
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| 
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|         case ModeLowerHalf:
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|             m_workFunction = &IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateLowerHalf;
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|             break;
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| 
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|         case ModeUpperHalf:
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|             m_workFunction = &IntHalfbandFilterEO<qint32, qint32, DOWNCHANNELIZER_HB_FILTER_ORDER, true>::workDecimateUpperHalf;
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|             break;
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|     }
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| }
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| #endif
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| 
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| DownChannelizer::FilterStage::~FilterStage()
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| {
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| 	delete m_filter;
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| }
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| 
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| Real DownChannelizer::channelMinSpace(Real sigStart, Real sigEnd, Real chanStart, Real chanEnd)
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| {
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|     Real leftSpace = chanStart - sigStart;
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|     Real rightSpace = sigEnd - chanEnd;
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|     return std::min(leftSpace, rightSpace);
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| }
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| 
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| Real DownChannelizer::createFilterChain(Real sigStart, Real sigEnd, Real chanStart, Real chanEnd)
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| {
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| 	Real sigBw = sigEnd - sigStart;
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|     Real chanBw = chanEnd - chanStart;
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| 	Real rot = sigBw / 4;
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| 
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| 
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|     std::array<Real, 3> filterMinSpaces; // Array of left, center and right filter min spaces respectively
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|     filterMinSpaces[0] = channelMinSpace(sigStart, sigStart + sigBw / 2.0, chanStart, chanEnd);
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|     filterMinSpaces[1] = channelMinSpace(sigStart + rot, sigEnd - rot, chanStart, chanEnd);
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|     filterMinSpaces[2] = channelMinSpace(sigEnd - sigBw / 2.0f, sigEnd, chanStart, chanEnd);
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|     auto maxIt = std::max_element(filterMinSpaces.begin(), filterMinSpaces.end());
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|     int maxIndex = maxIt - filterMinSpaces.begin();
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|     Real maxValue = *maxIt;
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| 
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| 	qDebug("DownChannelizer::createFilterChain: Signal [%.1f, %.1f] (BW %.1f) Channel [%.1f, %.1f] (BW %.1f) Selected: %d (fit %.1f)",
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|         sigStart, sigEnd, sigBw, chanStart, chanEnd, chanBw, maxIndex, maxValue);
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| 
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|     if ((sigStart < sigEnd) && (chanStart < chanEnd) && (maxValue >= chanBw/8.0))
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|     {
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|         if (maxIndex == 0)
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|         {
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|             m_filterStages.push_back(new FilterStage(FilterStage::ModeLowerHalf));
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|             return createFilterChain(sigStart, sigStart + sigBw / 2.0, chanStart, chanEnd);
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|         }
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| 
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|         if (maxIndex == 1)
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|         {
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|             m_filterStages.push_back(new FilterStage(FilterStage::ModeCenter));
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|             return createFilterChain(sigStart + rot, sigEnd - rot, chanStart, chanEnd);
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|         }
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| 
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|         if (maxIndex == 2)
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|         {
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|             m_filterStages.push_back(new FilterStage(FilterStage::ModeUpperHalf));
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|             return createFilterChain(sigEnd - sigBw / 2.0f, sigEnd, chanStart, chanEnd);
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|         }
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|     }
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| 
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| 	Real ofs = ((chanEnd - chanStart) / 2.0 + chanStart) - ((sigEnd - sigStart) / 2.0 + sigStart);
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| 	qDebug("DownChannelizer::createFilterChain: -> complete (final BW %.1f, frequency offset %.1f)", sigBw, ofs);
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| 	return ofs;
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| }
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| 
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| double DownChannelizer::setFilterChain(const std::vector<unsigned int>& stageIndexes)
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| {
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|     // filters are described from lower to upper level but the chain is constructed the other way round
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|     std::vector<unsigned int>::const_reverse_iterator rit = stageIndexes.rbegin();
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|     double ofs = 0.0, ofs_stage = 0.25;
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| 
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|     // Each index is a base 3 number with 0 = low, 1 = center, 2 = high
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|     // Functions at upper level will convert a number to base 3 to describe the filter chain. Common converting
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|     // algorithms will go from LSD to MSD. This explains the reverse order.
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|     for (; rit != stageIndexes.rend(); ++rit)
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|     {
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|         if (*rit == 0)
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|         {
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|             m_filterStages.push_back(new FilterStage(FilterStage::ModeLowerHalf));
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|             ofs -= ofs_stage;
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|             qDebug("DownChannelizer::setFilterChain: lower half: ofs: %f", ofs);
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|         }
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|         else if (*rit == 1)
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|         {
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|             m_filterStages.push_back(new FilterStage(FilterStage::ModeCenter));
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|             qDebug("DownChannelizer::setFilterChain: center: ofs: %f", ofs);
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|         }
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|         else if (*rit == 2)
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|         {
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|             m_filterStages.push_back(new FilterStage(FilterStage::ModeUpperHalf));
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|             ofs += ofs_stage;
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|             qDebug("DownChannelizer::setFilterChain: upper half: ofs: %f", ofs);
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|         }
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|     }
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| 
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|     return ofs;
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| }
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| 
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| void DownChannelizer::freeFilterChain()
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| {
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| 	for(FilterStages::iterator it = m_filterStages.begin(); it != m_filterStages.end(); ++it)
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| 		delete *it;
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| 	m_filterStages.clear();
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| }
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| 
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| void DownChannelizer::debugFilterChain()
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| {
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|     qDebug("DownChannelizer::debugFilterChain: %lu stages", m_filterStages.size());
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| 
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|     for(FilterStages::iterator it = m_filterStages.begin(); it != m_filterStages.end(); ++it)
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|     {
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|         switch ((*it)->m_mode)
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|         {
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|         case FilterStage::ModeCenter:
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|             qDebug("DownChannelizer::debugFilterChain: center %s", (*it)->m_sse ? "sse" : "no_sse");
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|             break;
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|         case FilterStage::ModeLowerHalf:
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|             qDebug("DownChannelizer::debugFilterChain: lower %s", (*it)->m_sse ? "sse" : "no_sse");
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|             break;
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|         case FilterStage::ModeUpperHalf:
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|             qDebug("DownChannelizer::debugFilterChain: upper %s", (*it)->m_sse ? "sse" : "no_sse");
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|             break;
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|         default:
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|             qDebug("DownChannelizer::debugFilterChain: none %s", (*it)->m_sse ? "sse" : "no_sse");
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|             break;
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|         }
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|     }
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| }
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