AM demod: synchronous AM: implemented sidebands selection

debian/changelog

@@ -1,8 +1,10 @@
 sdrangel (3.14.7-1) unstable; urgency=medium
 
   * ChanelAnalyzerNG: added PLL option
+  * RTL-SDR: fixed inf/sup decimators
+  * AM demod: syncrhronous AM detection option
 
- -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Sun, 13 May 2018 20:14:18 +0200
+ -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Sun, 20 May 2018 20:14:18 +0200
 
 sdrangel (3.14.6-1) unstable; urgency=medium
 

plugins/channelrx/chanalyzerng/chanalyzerng.cpp

@@ -35,7 +35,6 @@ const QString ChannelAnalyzerNG::m_channelId = "ChannelAnalyzerNG";
 ChannelAnalyzerNG::ChannelAnalyzerNG(DeviceSourceAPI *deviceAPI) :
         ChannelSinkAPI(m_channelIdURI),
         m_deviceAPI(deviceAPI),
-        m_pll(0,0.05,0.01),
         m_sampleSink(0),
         m_settingsMutex(QMutex::Recursive)
 {
@@ -50,6 +49,7 @@ ChannelAnalyzerNG::ChannelAnalyzerNG(DeviceSourceAPI *deviceAPI) :
 	m_interpolatorDistanceRemain = 0.0f;
 	SSBFilter = new fftfilt(m_config.m_LowCutoff / m_config.m_inputSampleRate, m_config.m_Bandwidth / m_config.m_inputSampleRate, ssbFftLen);
 	DSBFilter = new fftfilt(m_config.m_Bandwidth / m_config.m_inputSampleRate, 2*ssbFftLen);
+	m_pll.computeCoefficients(0.05f, 0.707f, 1000.0f); // bandwidth, damping factor, loop gain
 
     apply(true);
 
@@ -249,6 +249,13 @@ void ChannelAnalyzerNG::apply(bool force)
         m_settingsMutex.unlock();
     }
 
+    if (m_running.m_pll != m_config.m_pll || force)
+    {
+        if (m_config.m_pll) {
+            m_pll.reset();
+        }
+    }
+
     m_running.m_frequency = m_config.m_frequency;
     m_running.m_channelSampleRate = m_config.m_channelSampleRate;
     m_running.m_inputSampleRate = m_config.m_inputSampleRate;

plugins/channelrx/chanalyzerng/chanalyzerng.h

@@ -25,7 +25,7 @@
 #include "dsp/interpolator.h"
 #include "dsp/ncof.h"
 #include "dsp/fftfilt.h"
-#include "dsp/phaselock.h"
+#include "dsp/phaselockcomplex.h"
 #include "audio/audiofifo.h"
 #include "util/message.h"
 
@@ -148,6 +148,9 @@ public:
     int getChannelSampleRate() const { return m_running.m_channelSampleRate; }
 	double getMagSq() const { return m_magsq; }
 	bool isPllLocked() const { return m_running.m_pll && m_pll.locked(); }
+	Real getPllFrequency() const { return m_pll.getFrequency(); }
+	Real getPllDeltaPhase() const { return m_pll.getDeltaPhi(); }
+    Real getPllPhase() const { return m_pll.getPhiHat(); }
 
 	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool positiveOnly);
 	virtual void start();
@@ -203,7 +206,7 @@ private:
 	bool m_useInterpolator;
 
 	NCOF m_nco;
-	SimplePhaseLock m_pll;
+	PhaseLockComplex m_pll;
     Interpolator m_interpolator;
     Real m_interpolatorDistance;
     Real m_interpolatorDistanceRemain;
@@ -247,11 +250,13 @@ private:
 
                 if (m_running.m_pll)
                 {
-                    Real ncopll[2];
+                    m_pll.feed(re, im);
-                    m_pll.process(re, im, ncopll);
 
-                    Real mixI = m_sum.real() * ncopll[0] - m_sum.imag() * ncopll[1];
+                    // Use -fPLL to mix (exchange PLL real and image in the complex multiplication)
-                    Real mixQ = m_sum.real() * ncopll[1] + m_sum.imag() * ncopll[0];
+                    Real mixI = m_sum.real() * m_pll.getImag() - m_sum.imag() * m_pll.getReal();
+                    Real mixQ = m_sum.real() * m_pll.getReal() + m_sum.imag() * m_pll.getImag();
+//                    Real mixI = m_pll.getReal() * SDR_RX_SCALED;
+//                    Real mixQ = m_pll.getImag() * SDR_RX_SCALED;
 
                     if (m_running.m_ssb & !m_usb)
                     { // invert spectrum for LSB

plugins/channelrx/chanalyzerng/chanalyzernggui.cpp

@@ -243,6 +243,15 @@ void ChannelAnalyzerNGGUI::tick()
 	} else {
 	    ui->pll->setStyleSheet("QToolButton { background:rgb(79,79,79); }");
 	}
+
+	if (ui->pll->isChecked())
+	{
+	    int fHz = round(m_channelAnalyzer->getPllFrequency()*m_rate);
+	    ui->pll->setToolTip(tr("PLL lock (f:%1 Hz e:%2 rad p:%3 rad)")
+	            .arg(fHz)
+	            .arg(m_channelAnalyzer->getPllDeltaPhase())
+	            .arg(m_channelAnalyzer->getPllPhase()));
+	}
 }
 
 void ChannelAnalyzerNGGUI::on_channelSampleRate_changed(quint64 value)
@@ -257,8 +266,13 @@ void ChannelAnalyzerNGGUI::on_channelSampleRate_changed(quint64 value)
     }
 }
 
-void ChannelAnalyzerNGGUI::on_pll_toggled(bool checked __attribute__((unused)))
+void ChannelAnalyzerNGGUI::on_pll_toggled(bool checked)
 {
+    if (!checked && m_usePll) {
+        ui->pll->setToolTip("PLL lock");
+    }
+
+    m_usePll = checked;
     applySettings();
 }
 
@@ -399,7 +413,8 @@ ChannelAnalyzerNGGUI::ChannelAnalyzerNGGUI(PluginAPI* pluginAPI, DeviceUISet *de
 	m_channelMarker(this),
 	m_doApplySettings(true),
 	m_rate(6000),
-	m_spanLog2(0)
+	m_spanLog2(0),
+	m_usePll(false)
 {
 	ui->setupUi(this);
 	setAttribute(Qt::WA_DeleteOnClose, true);

plugins/channelrx/chanalyzerng/chanalyzernggui.h

@@ -66,6 +66,7 @@ private:
 	bool m_doApplySettings;
 	int m_rate; //!< sample rate after final in-channel decimation (spanlog2)
 	int m_spanLog2;
+	bool m_usePll;
 	MovingAverageUtil<Real, double, 40> m_channelPowerDbAvg;
 
 	ChannelAnalyzerNG* m_channelAnalyzer;

plugins/channelrx/demodam/CMakeLists.txt

@@ -7,6 +7,7 @@ set(am_SOURCES
 	amdemodgui.cpp
 	amdemodsettings.cpp
 	amdemodplugin.cpp
+	amdemodssbdialog.cpp
 )
 
 set(am_HEADERS
@@ -14,10 +15,12 @@ set(am_HEADERS
 	amdemodgui.h
 	amdemodsettings.h
 	amdemodplugin.h
+	amdemodssbdialog.h
 )
 
 set(am_FORMS
 	amdemodgui.ui
+	amdemodssb.ui
 )
 
 include_directories(

plugins/channelrx/demodam/amdemod.cpp

@@ -67,6 +67,7 @@ AMDemod::AMDemod(DeviceSourceAPI *deviceAPI) :
 	DSPEngine::instance()->getAudioDeviceManager()->addAudioSink(&m_audioFifo, getInputMessageQueue());
 	m_audioSampleRate = DSPEngine::instance()->getAudioDeviceManager()->getOutputSampleRate();
     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);
 
     applyChannelSettings(m_inputSampleRate, m_inputFrequencyOffset, true);
     applySettings(m_settings, true);
@@ -89,6 +90,7 @@ AMDemod::~AMDemod()
     delete m_threadedChannelizer;
     delete m_channelizer;
     delete DSBFilter;
+    delete SSBFilter;
 }
 
 void AMDemod::feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool firstOfBurst __attribute__((unused)))
@@ -233,6 +235,7 @@ void AMDemod::applyAudioSampleRate(int sampleRate)
     m_inputMessageQueue.push(channelConfigMsg);
 
     m_settingsMutex.lock();
+
     m_interpolator.create(16, m_inputSampleRate, m_settings.m_rfBandwidth / 2.2f);
     m_interpolatorDistanceRemain = 0;
     m_interpolatorDistance = (Real) m_inputSampleRate / (Real) sampleRate;
@@ -241,8 +244,14 @@ void AMDemod::applyAudioSampleRate(int sampleRate)
     m_squelchDelayLine.resize(sampleRate/5);
     DSBFilter->create_dsb_filter((2.0f * m_settings.m_rfBandwidth) / (float) sampleRate);
     m_pllFilt.create(101, sampleRate, 500.0);
-    m_settingsMutex.unlock();
 
+    if (m_settings.m_pll) {
+        m_volumeAGC.resizeNew(sampleRate, 0.003);
+    } else {
+        m_volumeAGC.resizeNew(sampleRate/10, 0.003);
+    }
+
+    m_settingsMutex.unlock();
     m_audioSampleRate = sampleRate;
 }
 
@@ -282,6 +291,7 @@ void AMDemod::applySettings(const AMDemodSettings& settings, bool force)
             << " 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) ||
@@ -314,6 +324,23 @@ void AMDemod::applySettings(const AMDemodSettings& settings, bool force)
         }
     }
 
+    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;
 }
 

plugins/channelrx/demodam/amdemod.h

@@ -167,11 +167,12 @@ private:
 	int  m_magsqCount;
 
 	MovingAverageUtil<Real, double, 16> m_movingAverage;
-	SimpleAGC<4096> m_volumeAGC;
+	SimpleAGC<4800> m_volumeAGC;
     Bandpass<Real> m_bandpass;
     Lowpass<std::complex<float> > m_pllFilt;
     PhaseLockComplex m_pll;
     fftfilt* DSBFilter;
+    fftfilt* SSBFilter;
     Real m_syncAMBuff[2*1024];
     uint32_t m_syncAMBuffIndex;
 
@@ -238,16 +239,29 @@ private:
 
                 fftfilt::cmplx *sideband;
                 std::complex<float> cs(yr, yi);
-                int n_out = DSBFilter->runDSB(cs, &sideband, false);
+                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++)
                 {
-                    m_syncAMBuff[i] = (sideband[i].real() + sideband[i].imag());
+                    if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMDSB) {
+                        m_syncAMBuff[i] = (sideband[i].real() + sideband[i].imag())/2.0f;
+                    } else if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMUSB) {
+                        m_syncAMBuff[i] = (sideband[i].real() + sideband[i].imag());
+                    } else {
+                        m_syncAMBuff[i] = (sideband[i].real() + sideband[i].imag());
+                    }
+
                     m_syncAMBuffIndex = 0;
                 }
 
                 m_syncAMBuffIndex = m_syncAMBuffIndex < 2*1024 ? m_syncAMBuffIndex : 0;
-                demod = m_syncAMBuff[m_syncAMBuffIndex++]*0.7*(SDR_RX_SCALEF/602.0f);
+                demod = m_syncAMBuff[m_syncAMBuffIndex++]*(SDR_RX_SCALEF/602.0f);
                 m_volumeAGC.feed(demod);
                 demod /= (10.0*m_volumeAGC.getValue());
             }

plugins/channelrx/demodam/amdemodgui.cpp

@@ -18,6 +18,7 @@
 #include <QMainWindow>
 
 #include "amdemodgui.h"
+#include "amdemodssbdialog.h"
 
 #include "device/devicesourceapi.h"
 #include "device/deviceuiset.h"
@@ -149,6 +150,12 @@ void AMDemodGUI::on_pll_toggled(bool checked)
     applySettings();
 }
 
+void AMDemodGUI::on_ssb_toggled(bool checked)
+{
+    m_settings.m_syncAMOperation = checked ? m_samUSB ? AMDemodSettings::SyncAMUSB : AMDemodSettings::SyncAMLSB : AMDemodSettings::SyncAMDSB;
+    applySettings();
+}
+
 void AMDemodGUI::on_bandpassEnable_toggled(bool checked)
 {
     m_settings.m_bandpassEnable = checked;
@@ -215,6 +222,7 @@ AMDemodGUI::AMDemodGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, BasebandS
 	m_channelMarker(this),
 	m_doApplySettings(true),
 	m_squelchOpen(false),
+	m_samUSB(true),
 	m_tickCount(0)
 {
 	ui->setupUi(this);
@@ -230,6 +238,9 @@ AMDemodGUI::AMDemodGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, BasebandS
 	CRightClickEnabler *audioMuteRightClickEnabler = new CRightClickEnabler(ui->audioMute);
 	connect(audioMuteRightClickEnabler, SIGNAL(rightClick()), this, SLOT(audioSelect()));
 
+	CRightClickEnabler *samSidebandRightClickEnabler = new CRightClickEnabler(ui->ssb);
+    connect(samSidebandRightClickEnabler, SIGNAL(rightClick()), this, SLOT(samSSBSelect()));
+
     ui->deltaFrequencyLabel->setText(QString("%1f").arg(QChar(0x94, 0x03)));
     ui->deltaFrequency->setColorMapper(ColorMapper(ColorMapper::GrayGold));
     ui->deltaFrequency->setValueRange(false, 7, -9999999, 9999999);
@@ -254,6 +265,11 @@ AMDemodGUI::AMDemodGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, BasebandS
     connect(&m_channelMarker, SIGNAL(highlightedByCursor()), this, SLOT(channelMarkerHighlightedByCursor()));
     connect(getInputMessageQueue(), SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
 
+    m_iconDSBUSB.addPixmap(QPixmap("://dsb.png"), QIcon::Normal, QIcon::Off);
+    m_iconDSBUSB.addPixmap(QPixmap("://usb.png"), QIcon::Normal, QIcon::On);
+    m_iconDSBLSB.addPixmap(QPixmap("://dsb.png"), QIcon::Normal, QIcon::Off);
+    m_iconDSBLSB.addPixmap(QPixmap("://lsb.png"), QIcon::Normal, QIcon::On);
+
 	displaySettings();
 	applySettings(true);
 }
@@ -314,6 +330,20 @@ void AMDemodGUI::displaySettings()
     ui->bandpassEnable->setChecked(m_settings.m_bandpassEnable);
     ui->pll->setChecked(m_settings.m_pll);
 
+    if (m_settings.m_pll) {
+        if (m_settings.m_syncAMOperation == AMDemodSettings::SyncAMLSB) {
+            m_samUSB = false;
+            ui->ssb->setIcon(m_iconDSBLSB);
+        } else {
+            m_samUSB = true;
+            ui->ssb->setIcon(m_iconDSBUSB);
+        }
+    }
+    else
+    {
+        ui->ssb->setIcon(m_iconDSBUSB);
+    }
+
     blockApplySettings(false);
 }
 
@@ -340,6 +370,26 @@ void AMDemodGUI::audioSelect()
     }
 }
 
+void AMDemodGUI::samSSBSelect()
+{
+    AMDemodSSBDialog ssbSelect(m_samUSB);
+    ssbSelect.exec();
+
+    ui->ssb->setIcon(ssbSelect.isUsb() ? m_iconDSBUSB : m_iconDSBLSB);
+
+    if (ssbSelect.isUsb() != m_samUSB)
+    {
+        qDebug("AMDemodGUI::samSSBSelect: %s", ssbSelect.isUsb() ? "usb" : "lsb");
+        m_samUSB = ssbSelect.isUsb();
+
+        if (m_settings.m_syncAMOperation != AMDemodSettings::SyncAMDSB)
+        {
+            m_settings.m_syncAMOperation = m_samUSB ? AMDemodSettings::SyncAMUSB : AMDemodSettings::SyncAMLSB;
+            applySettings();
+        }
+    }
+}
+
 void AMDemodGUI::tick()
 {
     double magsqAvg, magsqPeak;

plugins/channelrx/demodam/amdemodgui.h

@@ -1,7 +1,9 @@
 #ifndef INCLUDE_AMDEMODGUI_H
 #define INCLUDE_AMDEMODGUI_H
 
-#include <plugin/plugininstancegui.h>
+#include <QIcon>
+
+#include "plugin/plugininstancegui.h"
 #include "gui/rollupwidget.h"
 #include "dsp/channelmarker.h"
 #include "dsp/movingaverage.h"
@@ -50,9 +52,13 @@ private:
 
 	AMDemod* m_amDemod;
 	bool m_squelchOpen;
+	bool m_samUSB;
 	uint32_t m_tickCount;
 	MessageQueue m_inputMessageQueue;
 
+    QIcon m_iconDSBUSB;
+    QIcon m_iconDSBLSB;
+
 	explicit AMDemodGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, BasebandSampleSink *rxChannel, QWidget* parent = 0);
 	virtual ~AMDemodGUI();
 
@@ -66,6 +72,7 @@ private:
 private slots:
 	void on_deltaFrequency_changed(qint64 value);
 	void on_pll_toggled(bool checked);
+	void on_ssb_toggled(bool checked);
 	void on_bandpassEnable_toggled(bool checked);
 	void on_rfBW_valueChanged(int value);
 	void on_volume_valueChanged(int value);
@@ -75,6 +82,7 @@ private slots:
     void onMenuDialogCalled(const QPoint& p);
     void handleInputMessages();
     void audioSelect();
+    void samSSBSelect();
 	void tick();
 };
 

plugins/channelrx/demodam/amdemodgui.ui

@@ -154,6 +154,24 @@
           </property>
          </widget>
         </item>
+        <item>
+         <widget class="QToolButton" name="ssb">
+          <property name="toolTip">
+           <string>Synchronous AM SSB/DSB toggle right click to select side band</string>
+          </property>
+          <property name="text">
+           <string/>
+          </property>
+          <property name="icon">
+           <iconset resource="../../../sdrgui/resources/res.qrc">
+            <normaloff>:/dsb.png</normaloff>
+            <normalon>:/usb.png</normalon>:/dsb.png</iconset>
+          </property>
+          <property name="checkable">
+           <bool>true</bool>
+          </property>
+         </widget>
+        </item>
         <item>
          <spacer name="horizontalSpacer">
           <property name="orientation">

plugins/channelrx/demodam/amdemodsettings.cpp

@@ -39,6 +39,7 @@ void AMDemodSettings::resetToDefaults()
     m_title = "AM Demodulator";
     m_audioDeviceName = AudioDeviceManager::m_defaultDeviceName;
     m_pll = false;
+    m_syncAMOperation = SyncAMDSB;
 }
 
 QByteArray AMDemodSettings::serialize() const
@@ -58,6 +59,7 @@ QByteArray AMDemodSettings::serialize() const
     s.writeString(9, m_title);
     s.writeString(11, m_audioDeviceName);
     s.writeBool(12, m_pll);
+    s.writeS32(13, (int) m_syncAMOperation);
 
     return s.final();
 }
@@ -96,6 +98,8 @@ bool AMDemodSettings::deserialize(const QByteArray& data)
         d.readString(9, &m_title, "AM Demodulator");
         d.readString(11, &m_audioDeviceName, AudioDeviceManager::m_defaultDeviceName);
         d.readBool(12, &m_pll, false);
+        d.readS32(13, &tmp, 0);
+        m_syncAMOperation = tmp < 0 ? SyncAMDSB : tmp > 2 ? SyncAMDSB : (SyncAMOperation) tmp;
 
         return true;
     }

plugins/channelrx/demodam/amdemodsettings.h

@@ -23,6 +23,13 @@ class Serializable;
 
 struct AMDemodSettings
 {
+    enum SyncAMOperation
+    {
+        SyncAMDSB,
+        SyncAMUSB,
+        SyncAMLSB
+    };
+
     qint32 m_inputFrequencyOffset;
     Real m_rfBandwidth;
     Real m_squelch;
@@ -34,6 +41,7 @@ struct AMDemodSettings
     Serializable *m_channelMarker;
     QString m_audioDeviceName;
     bool m_pll;
+    SyncAMOperation m_syncAMOperation;
 
     AMDemodSettings();
     void resetToDefaults();

plugins/channelrx/demodam/amdemodssb.ui

@@ -0,0 +1,96 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>AMDemodSSBDialog</class>
+ <widget class="QDialog" name="AMDemodSSBDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>199</width>
+    <height>115</height>
+   </rect>
+  </property>
+  <property name="font">
+   <font>
+    <family>Liberation Sans</family>
+    <pointsize>9</pointsize>
+   </font>
+  </property>
+  <property name="windowTitle">
+   <string>Dialog</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QGroupBox" name="groupBox">
+     <property name="title">
+      <string>SAM sideband selection</string>
+     </property>
+     <layout class="QFormLayout" name="formLayout">
+      <item row="1" column="0">
+       <widget class="QRadioButton" name="lsb">
+        <property name="text">
+         <string>LSB</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QRadioButton" name="usb">
+        <property name="text">
+         <string>USB</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <tabstops>
+  <tabstop>buttonBox</tabstop>
+ </tabstops>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>AMDemodSSBDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>257</x>
+     <y>194</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>203</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>AMDemodSSBDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>314</x>
+     <y>194</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>203</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>

plugins/channelrx/demodam/amdemodssbdialog.cpp

@@ -0,0 +1,41 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 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 "amdemodssbdialog.h"
+#include "ui_amdemodssb.h"
+
+AMDemodSSBDialog::AMDemodSSBDialog(bool usb, QWidget* parent) :
+    QDialog(parent),
+    ui(new Ui::AMDemodSSBDialog),
+    m_usb(usb)
+{
+    ui->setupUi(this);
+    ui->usb->setChecked(usb);
+    ui->lsb->setChecked(!usb);
+}
+
+AMDemodSSBDialog::~AMDemodSSBDialog()
+{
+    delete ui;
+}
+
+void AMDemodSSBDialog::accept()
+{
+    m_usb = ui->usb->isChecked();
+    QDialog::accept();
+}
+
+

plugins/channelrx/demodam/amdemodssbdialog.h

@@ -0,0 +1,43 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 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/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef PLUGINS_CHANNELRX_DEMODAM_AMDEMODSSBDIALOG_H_
+#define PLUGINS_CHANNELRX_DEMODAM_AMDEMODSSBDIALOG_H_
+
+#include <QDialog>
+
+namespace Ui {
+    class AMDemodSSBDialog;
+}
+
+class AMDemodSSBDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    explicit AMDemodSSBDialog(bool usb, QWidget* parent = 0);
+    ~AMDemodSSBDialog();
+
+    bool isUsb() const { return m_usb; }
+
+private:
+    Ui::AMDemodSSBDialog* ui;
+    bool m_usb;
+
+private slots:
+    void accept();
+};
+
+#endif /* PLUGINS_CHANNELRX_DEMODAM_AMDEMODSSBDIALOG_H_ */

sdrbase/dsp/agc.h

@@ -89,6 +89,13 @@ public:
         m_moving_average.resize(AvgSize, initial);
 	}
 
+    void resizeNew(uint32_t newSize, Real initial, Real cutoff=0, Real clip=0)
+    {
+        m_cutoff = cutoff;
+        m_clip = clip;
+        m_moving_average.resize(newSize, initial);
+    }
+
     void fill(double value)
     {
         m_moving_average.fill(value);

sdrbase/dsp/recursivefilters.cpp

@@ -18,11 +18,12 @@
 #include "recursivefilters.h"
 
 #undef M_PI
-#define M_PI		3.14159265358979323846
+#define M_PI 3.14159265358979323846
 
 SecondOrderRecursiveFilter::SecondOrderRecursiveFilter(float samplingFrequency, float centerFrequency, float r) :
         m_r(r),
-        m_frequencyRatio(centerFrequency/samplingFrequency)
+        m_frequencyRatio(centerFrequency/samplingFrequency),
+        m_f(cos(2.0*M_PI*(m_frequencyRatio)))
 {
     init();
 }
@@ -33,6 +34,7 @@ SecondOrderRecursiveFilter::~SecondOrderRecursiveFilter()
 void SecondOrderRecursiveFilter::setFrequencies(float samplingFrequency, float centerFrequency)
 {
     m_frequencyRatio = centerFrequency / samplingFrequency;
+    m_f = cos(2.0*M_PI*m_frequencyRatio);
     init();
 }
 
@@ -44,7 +46,7 @@ void SecondOrderRecursiveFilter::setR(float r)
 
 short SecondOrderRecursiveFilter::run(short sample)
 {
-    m_v[0] = ((1.0f - m_r) * (float) sample) + (2.0f * m_r * cos(2.0*M_PI*m_frequencyRatio) * m_v[1]) - (m_r * m_r * m_v[2]);
+    m_v[0] = ((1.0f - m_r) * (float) sample) + (2.0f * m_r * m_f * m_v[1]) - (m_r * m_r * m_v[2]);
     float y = m_v[0] - m_v[2];
     m_v[2] = m_v[1];
     m_v[1] = m_v[0];
@@ -54,7 +56,7 @@ short SecondOrderRecursiveFilter::run(short sample)
 
 float SecondOrderRecursiveFilter::run(float sample)
 {
-    m_v[0] = ((1.0f - m_r) * sample) + (2.0f * m_r * cos(2.0*M_PI*m_frequencyRatio) * m_v[1]) - (m_r * m_r * m_v[2]);
+    m_v[0] = ((1.0f - m_r) * sample) + (2.0f * m_r * m_f * m_v[1]) - (m_r * m_r * m_v[2]);
     float y = m_v[0] - m_v[2];
     m_v[2] = m_v[1];
     m_v[1] = m_v[0];

sdrbase/dsp/recursivefilters.h

@@ -39,6 +39,7 @@ private:
 
     float m_r;
     float m_frequencyRatio;
+    float m_f;
     float m_v[3];
 };