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Code Issues Packages Projects Releases 2 Wiki Activity

[WIP] Updating dsp modules to accept variable sample rate I/Q streams

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and creating a new audio resampler.
This commit is contained in:
Denny
2018-02-09 05:29:07 -05:00
parent 96d9d6f750
commit 28cb9d9407
15 changed files with 369 additions and 171 deletions
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18
src/main/java/io/github/dsheirer/module/decode/DecoderFactory.java
View File

@@ -101,6 +101,9 @@ public class DecoderFactory
{
private final static Logger mLog = LoggerFactory.getLogger(DecoderFactory.class);
private static final int NBFM_PASS_FREQUENCY = 6000;
private static final int NBFM_STOP_FREQUENCY = 6500;
//Low-pass filter with ~60 dB attenuation and 89 taps
private static final FIRFilterSpecification MPT1327_FILTER_SPECIFICATION = FIRFilterSpecification.lowPassBuilder()
.sampleRate( 48000 ).gridDensity( 16 ).passBandCutoff( 3200 ).passBandAmplitude( 1.0 ).passBandRipple( 0.02 )
@@ -174,9 +177,6 @@ public class DecoderFactory
/* Baseband low-pass filter pass and stop frequencies */
DecodeConfiguration decodeConfig = channel.getDecodeConfiguration();
int iqPass = decodeConfig.getDecoderType().getChannelBandwidth() / 2;
int iqStop = iqPass + 1250;
switch(decodeConfig.getDecoderType())
{
case AM:
@@ -189,7 +189,7 @@ public class DecoderFactory
case NBFM:
modules.add(new NBFMDecoder(decodeConfig));
modules.add(new AlwaysUnsquelchedDecoderState(DecoderType.NBFM, channel.getName()));
modules.add(new FMDemodulatorModule(iqPass, iqStop));
modules.add(new FMDemodulatorModule(NBFM_PASS_FREQUENCY, NBFM_STOP_FREQUENCY));
modules.add(new DemodulatedAudioFilterModule(4000, 6000));
modules.add(new AudioModule(metadata));
break;
@@ -197,14 +197,14 @@ public class DecoderFactory
MessageDirection direction = ((DecodeConfigLTRStandard) decodeConfig).getMessageDirection();
modules.add(new LTRStandardDecoder(aliasList, direction));
modules.add(new LTRStandardDecoderState(aliasList));
modules.add(new FMDemodulatorModule(iqPass, iqStop));
modules.add(new FMDemodulatorModule(NBFM_PASS_FREQUENCY, NBFM_STOP_FREQUENCY));
modules.add(new DemodulatedAudioFilterModule(4000, 6000));
modules.add(new AudioModule(metadata));
break;
case LTR_NET:
modules.add(new LTRNetDecoder((DecodeConfigLTRNet) decodeConfig, aliasList));
modules.add(new LTRNetDecoderState(aliasList));
modules.add(new FMDemodulatorModule(iqPass, iqStop));
modules.add(new FMDemodulatorModule(NBFM_PASS_FREQUENCY, NBFM_STOP_FREQUENCY));
modules.add(new DemodulatedAudioFilterModule(4000, 6000));
modules.add(new AudioModule(metadata));
break;
@@ -227,14 +227,14 @@ public class DecoderFactory
(aliasList != null ? aliasList.getName() : null), mptConfig.getTrafficChannelPoolSize()));
}
modules.add(new FMDemodulatorModule(iqPass, iqStop));
modules.add(new FMDemodulatorModule(NBFM_PASS_FREQUENCY, NBFM_STOP_FREQUENCY));
modules.add(new DemodulatedAudioFilterModule(P25_C4FM_DEMOD_FILTER, 1.0f));
modules.add(new AudioModule(metadata));
break;
case PASSPORT:
modules.add(new PassportDecoder(decodeConfig, aliasList));
modules.add(new PassportDecoderState(aliasList));
modules.add(new FMDemodulatorModule(iqPass, iqStop));
modules.add(new FMDemodulatorModule(NBFM_PASS_FREQUENCY, NBFM_STOP_FREQUENCY));
modules.add(new DemodulatedAudioFilterModule(4000, 6000));
modules.add(new AudioModule(metadata));
break;
@@ -247,7 +247,7 @@ public class DecoderFactory
switch(modulation)
{
case C4FM:
modules.add(new FMDemodulatorModule(P25_C4FM_IQ_FILTER));
// modules.add(new FMDemodulatorModule(P25_C4FM_IQ_FILTER));
modules.add(new DemodulatedAudioFilterModule(P25_C4FM_DEMOD_FILTER, 1.0f));
modules.add(new P25_C4FMDecoder(aliasList, decodeConfig.getAFCMaximumCorrection()));
modules.add(new P25DecoderState(aliasList, channelType, Modulation.C4FM,

2
src/main/java/io/github/dsheirer/module/decode/p25/P25_LSMDecoder.java
View File

@@ -235,7 +235,7 @@ public class P25_LSMDecoder extends P25Decoder implements IReusableComplexBuffer
@Override
public void receive(ReusableComplexBuffer reusableComplexBuffer)
{
float[] samples = reusableComplexBuffer.getCopyOfSamples();
float[] samples = reusableComplexBuffer.getSamplesCopy();
//TODO: redesign the filter chain so that we can simply pass a float array ...

2
src/main/java/io/github/dsheirer/module/demodulate/am/AMDemodulatorModule.java
View File

@@ -113,7 +113,7 @@ public class AMDemodulatorModule extends Module implements IReusableComplexBuffe
@Override
public void receive(ReusableComplexBuffer reusableComplexBuffer)
{
float[] samples = reusableComplexBuffer.getCopyOfSamples();
float[] samples = reusableComplexBuffer.getSamplesCopy();
//TODO: redesign the filter chain so that we can simply pass a float array ...

140
src/main/java/io/github/dsheirer/module/demodulate/fm/FMDemodulatorModule.java
View File

@@ -1,85 +1,84 @@
/*******************************************************************************
* SDR Trunk
* Copyright (C) 2014-2016 Dennis Sheirer
* sdr-trunk
* Copyright (C) 2014-2018 Dennis Sheirer
*
* 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, either version 3 of the License, or
* (at your option) any later version.
* 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, either 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 for more details.
* 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 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/>
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
******************************************************************************/
package io.github.dsheirer.module.demodulate.fm;
import io.github.dsheirer.dsp.filter.FilterFactory;
import io.github.dsheirer.dsp.filter.Window;
import io.github.dsheirer.dsp.filter.design.FilterDesignException;
import io.github.dsheirer.dsp.filter.fir.FIRFilterSpecification;
import io.github.dsheirer.dsp.filter.fir.complex.ComplexFIRFilter_CB_CB;
import io.github.dsheirer.dsp.fm.FMDemodulator_CB;
import io.github.dsheirer.module.Module;
import io.github.dsheirer.sample.Listener;
import io.github.dsheirer.sample.complex.ComplexBuffer;
import io.github.dsheirer.sample.complex.reusable.IReusableComplexBufferListener;
import io.github.dsheirer.sample.complex.reusable.ReusableComplexBuffer;
import io.github.dsheirer.sample.real.IUnFilteredRealBufferProvider;
import io.github.dsheirer.sample.real.RealBuffer;
import io.github.dsheirer.source.ISourceEventListener;
import io.github.dsheirer.source.SourceEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class FMDemodulatorModule extends Module implements IReusableComplexBufferListener, IUnFilteredRealBufferProvider
public class FMDemodulatorModule extends Module implements ISourceEventListener, IReusableComplexBufferListener,
IUnFilteredRealBufferProvider
{
private final static Logger mLog = LoggerFactory.getLogger(FMDemodulatorModule.class);
private static final int SAMPLE_RATE = 48000;
private ComplexFIRFilter_CB_CB mIQFilter;
private FMDemodulator_CB mDemodulator;
private ReusableBufferListener mReusableBufferListener = new ReusableBufferListener();
private ReusableBufferProcessor mReusableBufferProcessor = new ReusableBufferProcessor();
private SourceEventProcessor mSourceEventProcessor = new SourceEventProcessor();
private int mPassFrequency;
private int mStopFrequency;
/**
* FM Demodulator with I/Q filter. Demodulated output is unfiltered and
* may contain a DC component.
* FM Demodulator with I/Q filter. Demodulated output is unfiltered and may contain a DC component.
*
* @param pass - pass frequency for IQ filtering prior to demodulation. This
* frequency should be half of the signal bandwidth since the filter will
* frequency should be less than or equal to half of the signal bandwidth since the filter will
* be applied against each of the inphase and quadrature signals and the
* combined pass bandwidth will be twice this value.
* @param stop - stop frequency for IQ filtering prior to demodulation.
*/
public FMDemodulatorModule(int pass, int stop)
{
assert (stop > pass);
mIQFilter = new ComplexFIRFilter_CB_CB(FilterFactory.getLowPass(
SAMPLE_RATE, pass, stop, 60, Window.WindowType.HAMMING, true), 1.0f);
mDemodulator = new FMDemodulator_CB(1.0f);
mIQFilter.setListener(mDemodulator);
}
public FMDemodulatorModule(float[] filter)
{
mIQFilter = new ComplexFIRFilter_CB_CB(filter, 1.0f);
mDemodulator = new FMDemodulator_CB(1.0f);
mIQFilter.setListener(mDemodulator);
mPassFrequency = pass;
mStopFrequency = stop;
}
@Override
public Listener<ReusableComplexBuffer> getReusableComplexBufferListener()
{
return mReusableBufferListener;
return mReusableBufferProcessor;
}
@Override
public Listener<SourceEvent> getSourceEventListener()
{
return mSourceEventProcessor;
}
@Override
public void dispose()
{
mIQFilter.dispose();
mIQFilter = null;
if(mIQFilter != null)
{
mIQFilter.dispose();
mIQFilter = null;
}
mDemodulator.dispose();
mDemodulator = null;
@@ -113,17 +112,76 @@ public class FMDemodulatorModule extends Module implements IReusableComplexBuffe
{
}
public class ReusableBufferListener implements Listener<ReusableComplexBuffer>
/**
* Receives complex buffers and sends them through the filtering and demodulation process. Manages accounting for
* the reusable buffers.
*/
public class ReusableBufferProcessor implements Listener<ReusableComplexBuffer>
{
@Override
public void receive(ReusableComplexBuffer reusableComplexBuffer)
{
float[] samples = reusableComplexBuffer.getCopyOfSamples();
if(mIQFilter == null)
{
reusableComplexBuffer.decrementUserCount();
throw new IllegalStateException("FM demodulator module must receive a sample rate change source " +
"event before it can process complex sample buffers");
}
//TODO: redesign the filter chain so that we can simply pass a float array ...
float[] samples = reusableComplexBuffer.getSamplesCopy();
mIQFilter.receive(samples);
mIQFilter.receive(new ComplexBuffer(samples));
reusableComplexBuffer.decrementUserCount();
}
}
/**
* Monitors sample rate change source event(s) to setup the initial I/Q filter
*/
public class SourceEventProcessor implements Listener<SourceEvent>
{
@Override
public void receive(SourceEvent sourceEvent)
{
if(sourceEvent.getEvent() == SourceEvent.Event.NOTIFICATION_SAMPLE_RATE_CHANGE)
{
double sampleRate = sourceEvent.getValue().doubleValue();
float[] filterTaps = null;
FIRFilterSpecification specification = FIRFilterSpecification.lowPassBuilder()
.sampleRate(sampleRate)
.gridDensity(16)
.oddLength(true)
.passBandCutoff(mPassFrequency)
.passBandAmplitude(1.0)
.passBandRipple(0.01)
.stopBandStart(mStopFrequency)
.stopBandAmplitude(0.0)
.stopBandRipple(0.028) //Approximately 60 dB attenuation
.build();
try
{
filterTaps = FilterFactory.getTaps(specification);
}
catch(FilterDesignException fde)
{
mLog.error("Couldn't design FM demodulator remez filter for sample rate [" + sampleRate +
"] pass frequency [" + mPassFrequency + "] and stop frequency [" + mStopFrequency +
"] - using sinc filter");
}
if(filterTaps == null)
{
filterTaps = FilterFactory.getLowPass(sampleRate, mPassFrequency, mStopFrequency, 60,
Window.WindowType.HAMMING, true);
}
mIQFilter = new ComplexFIRFilter_CB_CB(filterTaps, 1.0f);
mIQFilter.setListener(mDemodulator);
}
}
}
}