SSB demod: make AGC clamping optional

plugins/channelrx/demodssb/ssbdemod.cpp

@@ -35,6 +35,7 @@ SSBDemod::SSBDemod(BasebandSampleSink* sampleSink) :
     m_audioMute(false),
     m_agc(12000, agcTarget, 1e-2),
     m_agcActive(false),
+    m_agcClamping(false),
     m_agcNbSamples(12000),
     m_agcPowerThreshold(1e-2),
     m_agcThresholdGate(0),
@@ -69,7 +70,7 @@ SSBDemod::SSBDemod(BasebandSampleSink* sampleSink) :
 	m_magsqCount = 0;
 
 	m_agc.setClampMax(32768.0*32768.0);
-	m_agc.setClamping(true);
+	m_agc.setClamping(m_agcClamping);
 
 	SSBFilter = new fftfilt(m_LowCutoff / m_audioSampleRate, m_Bandwidth / m_audioSampleRate, ssbFftLen);
 	DSBFilter = new fftfilt((2.0f * m_Bandwidth) / m_audioSampleRate, 2 * ssbFftLen);
@@ -95,6 +96,7 @@ void SSBDemod::configure(MessageQueue* messageQueue,
 		bool dsb,
 		bool audioMute,
 		bool agc,
+		bool agcClamping,
         int agcTimeLog2,
         int agcPowerThreshold,
         int agcThresholdGate)
@@ -109,6 +111,7 @@ void SSBDemod::configure(MessageQueue* messageQueue,
 	        dsb,
 	        audioMute,
 	        agc,
+	        agcClamping,
 	        agcTimeLog2,
 	        agcPowerThreshold,
 	        agcThresholdGate);
@@ -324,6 +327,7 @@ bool SSBDemod::handleMessage(const Message& cmd)
         m_agc.setThresholdEnable(cfg.getAGCPowerThershold() != -99);
 		double agcPowerThreshold = CalcDb::powerFromdB(cfg.getAGCPowerThershold()) * (1<<30);
 		int agcThresholdGate = 48 * cfg.getAGCThersholdGate(); // ms
+		bool agcClamping = cfg.getAGCClamping();
 
 		if (m_agcNbSamples != agcNbSamples)
 		{
@@ -344,6 +348,12 @@ bool SSBDemod::handleMessage(const Message& cmd)
 		    m_agcThresholdGate = agcThresholdGate;
 		}
 
+		if (m_agcClamping != agcClamping)
+		{
+		    m_agc.setClamping(agcClamping);
+		    m_agcClamping = agcClamping;
+		}
+
 		m_settingsMutex.unlock();
 
 		qDebug() << "SBDemod::handleMessage: MsgConfigureSSBDemod: m_Bandwidth: " << m_Bandwidth
@@ -355,6 +365,7 @@ bool SSBDemod::handleMessage(const Message& cmd)
 				<< " m_dsb: " << m_dsb
 				<< " m_audioMute: " << m_audioMute
 				<< " m_agcActive: " << m_agcActive
+				<< " m_agcClamping: " << m_agcClamping
 				<< " agcNbSamples: " << agcNbSamples
 				<< " agcPowerThreshold: " << agcPowerThreshold
 				<< " agcThresholdGate: " << agcThresholdGate;

plugins/channelrx/demodssb/ssbdemod.h

@@ -46,6 +46,7 @@ public:
 			bool dsb,
 			bool audioMute,
 			bool agc,
+			bool agcClamping,
 			int agcTimeLog2,
 			int agcPowerThreshold,
 			int agcThresholdGate);
@@ -83,6 +84,7 @@ private:
 		bool getDSB() const { return m_dsb; }
 		bool getAudioMute() const { return m_audioMute; }
 		bool getAGC() const { return m_agc; }
+		bool getAGCClamping() const { return m_agcClamping; }
 		int  getAGCTimeLog2() const { return m_agcTimeLog2; }
 		int  getAGCPowerThershold() const { return m_agcPowerThreshold; }
         int  getAGCThersholdGate() const { return m_agcThresholdGate; }
@@ -96,6 +98,7 @@ private:
 				bool dsb,
 				bool audioMute,
                 bool agc,
+                bool agcClamping,
                 int  agcTimeLog2,
                 int  agcPowerThreshold,
                 int  agcThresholdGate)
@@ -110,6 +113,7 @@ private:
 			        dsb,
 			        audioMute,
 			        agc,
+			        agcClamping,
 			        agcTimeLog2,
 			        agcPowerThreshold,
 			        agcThresholdGate);
@@ -125,6 +129,7 @@ private:
 		bool m_dsb;
 		bool m_audioMute;
 		bool m_agc;
+		bool m_agcClamping;
 		int  m_agcTimeLog2;
 		int  m_agcPowerThreshold;
 		int  m_agcThresholdGate;
@@ -138,6 +143,7 @@ private:
 				bool dsb,
 				bool audioMute,
 				bool agc,
+				bool agcClamping,
 				int  agcTimeLog2,
 				int  agcPowerThreshold,
 				int  agcThresholdGate) :
@@ -151,6 +157,7 @@ private:
 			m_dsb(dsb),
 			m_audioMute(audioMute),
 			m_agc(agc),
+			m_agcClamping(agcClamping),
 			m_agcTimeLog2(agcTimeLog2),
 			m_agcPowerThreshold(agcPowerThreshold),
 			m_agcThresholdGate(agcThresholdGate)
@@ -183,6 +190,7 @@ private:
     int  m_magsqCount;
     MagAGC m_agc;
     bool m_agcActive;
+    bool m_agcClamping;
     int m_agcNbSamples;         //!< number of audio (48 kHz) samples for AGC averaging
     double m_agcPowerThreshold; //!< AGC power threshold (linear)
     int m_agcThresholdGate;     //!< Gate length in number of samples befor threshold triggers

plugins/channelrx/demodssb/ssbdemodgui.cpp

@@ -86,6 +86,7 @@ QByteArray SSBDemodGUI::serialize() const
 	s.writeS32(12, ui->agcTimeLog2->value());
 	s.writeS32(13, ui->agcPowerThreshold->value());
     s.writeS32(14, ui->agcThresholdGate->value());
+    s.writeBool(15, ui->agcClamping->isChecked());
 	return s.final();
 }
 
@@ -139,6 +140,8 @@ bool SSBDemodGUI::deserialize(const QByteArray& data)
         ui->agcPowerThreshold->setValue(tmp);
         d.readS32(14, &tmp, 4);
         ui->agcThresholdGate->setValue(tmp);
+        d.readBool(15, &booltmp, false);
+        ui->agcClamping->setChecked(booltmp);
 
         displaySettings();
 
@@ -290,6 +293,11 @@ void SSBDemodGUI::on_agc_toggled(bool checked __attribute((__unused__)))
     applySettings();
 }
 
+void SSBDemodGUI::on_agcClamping_toggled(bool checked __attribute((__unused__)))
+{
+    applySettings();
+}
+
 void SSBDemodGUI::on_agcTimeLog2_valueChanged(int value)
 {
     QString s = QString::number((1<<value), 'f', 0);
@@ -518,6 +526,7 @@ void SSBDemodGUI::applySettings()
 			m_dsb,
 			ui->audioMute->isChecked(),
 			ui->agc->isChecked(),
+			ui->agcClamping->isChecked(),
 			ui->agcTimeLog2->value(),
 			ui->agcPowerThreshold->value(),
 			ui->agcThresholdGate->value());

plugins/channelrx/demodssb/ssbdemodgui.h

@@ -49,6 +49,7 @@ private slots:
 	void on_lowCut_valueChanged(int value);
 	void on_volume_valueChanged(int value);
 	void on_agc_toggled(bool checked);
+    void on_agcClamping_toggled(bool checked);
 	void on_agcTimeLog2_valueChanged(int value);
     void on_agcPowerThreshold_valueChanged(int value);
     void on_agcThresholdGate_valueChanged(int value);

plugins/channelrx/demodssb/ssbdemodgui.ui

@@ -474,6 +474,19 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="ButtonSwitch" name="agcClamping">
+        <property name="toolTip">
+         <string>Toggle AGC clamping to maximum allowable signal</string>
+        </property>
+        <property name="text">
+         <string>CL</string>
+        </property>
+        <property name="checkable">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
       <item>
        <widget class="QDial" name="agcTimeLog2">
         <property name="maximumSize">

plugins/channelrx/demodssb/ssbplugin.cpp

@@ -7,7 +7,7 @@
 
 const PluginDescriptor SSBPlugin::m_pluginDescriptor = {
 	QString("SSB Demodulator"),
-	QString("3.5.3"),
+	QString("3.5.4"),
 	QString("(c) Edouard Griffiths, F4EXB"),
 	QString("https://github.com/f4exb/sdrangel"),
 	true,