ATV Demod: FM mode using phaseDiscriminatorDelta with deviation scaling

plugins/channelrx/demodatv/atvdemod.cpp

@@ -76,6 +76,8 @@ ATVDemod::ATVDemod(BasebandSampleSink* objScopeSink) :
 
     memset((void*)m_fltBufferI,0,6*sizeof(float));
     memset((void*)m_fltBufferQ,0,6*sizeof(float));
+
+    m_objPhaseDiscri.setFMScaling(1.0f);
 }
 
 ATVDemod::~ATVDemod()
@@ -119,7 +121,8 @@ void ATVDemod::configureRF(
         float fltRFOppBandwidth,
         bool blnFFTFiltering,
         bool blnDecimatorEnable,
-        float fltBFOFrequency)
+        float fltBFOFrequency,
+        float fmDeviation)
 {
     Message* msgCmd = MsgConfigureRFATVDemod::create(
             enmModulation,
@@ -127,7 +130,8 @@ void ATVDemod::configureRF(
             fltRFOppBandwidth,
             blnFFTFiltering,
             blnDecimatorEnable,
-            fltBFOFrequency);
+            fltBFOFrequency,
+            fmDeviation);
     objMessageQueue->push(msgCmd);
 }
 
@@ -272,15 +276,14 @@ void ATVDemod::demod(Complex& c)
     float& fltI = m_objRFRunning.m_blnFFTFiltering ? m_DSBFilterBuffer[m_DSBFilterBufferIndex-1].real() : c.real();
     float& fltQ = m_objRFRunning.m_blnFFTFiltering ? m_DSBFilterBuffer[m_DSBFilterBufferIndex-1].imag() : c.imag();
 #endif
-    double magSq = fltI*fltI + fltQ*fltQ;
+    double magSq;
-    m_objMagSqAverage.feed(magSq);
-
-    fltNorm = sqrt(magSq);
 
     if ((m_objRFRunning.m_enmModulation == ATV_FM1) || (m_objRFRunning.m_enmModulation == ATV_FM2))
     {
         //Amplitude FM
-
+        magSq = fltI*fltI + fltQ*fltQ;
+        m_objMagSqAverage.feed(magSq);
+        fltNorm = sqrt(magSq);
         fltNormI= fltI/fltNorm;
         fltNormQ= fltQ/fltNorm;
 
@@ -324,11 +327,13 @@ void ATVDemod::demod(Complex& c)
 
         m_fltBufferI[0]=fltNormI;
         m_fltBufferQ[0]=fltNormQ;
-
     }
     else if (m_objRFRunning.m_enmModulation == ATV_AM)
     {
         //Amplitude AM
+        magSq = fltI*fltI + fltQ*fltQ;
+        m_objMagSqAverage.feed(magSq);
+        fltNorm = sqrt(magSq);
         fltVal = fltNorm;
 
         //********** Mini and Maxi Amplitude tracking **********
@@ -349,6 +354,10 @@ void ATVDemod::demod(Complex& c)
     }
     else if ((m_objRFRunning.m_enmModulation == ATV_USB) || (m_objRFRunning.m_enmModulation == ATV_LSB))
     {
+        magSq = fltI*fltI + fltQ*fltQ;
+        m_objMagSqAverage.feed(magSq);
+        fltNorm = sqrt(magSq);
+
         Real bfoValues[2];
         float fltFiltered = m_bfoFilter.run(fltI);
         m_bfoPLL.process(fltFiltered, bfoValues);
@@ -380,12 +389,23 @@ void ATVDemod::demod(Complex& c)
         fltVal -= m_fltAmpMin;
         fltVal /=m_fltAmpDelta;
     }
+    else if (m_objRFRunning.m_enmModulation == ATV_FM3)
+    {
+        float rawDeviation;
+        fltVal = (m_objPhaseDiscri.phaseDiscriminatorDelta(c, magSq, rawDeviation)/ m_objRFRunning.m_fmDeviation) + 0.5f;
+        fltVal = fltVal < 0.0f ? 0.0f : fltVal > 1.0f ? 1.0f : fltVal;
+        m_objMagSqAverage.feed(magSq);
+        fltNorm = sqrt(magSq);
+    }
     else
     {
+        magSq = fltI*fltI + fltQ*fltQ;
+        m_objMagSqAverage.feed(magSq);
+        fltNorm = sqrt(magSq);
         fltVal = 0.0f;
     }
 
-    m_objScopeSampleBuffer.push_back(Sample(fltVal*32768.0f, 0.0f));
+    m_objScopeSampleBuffer.push_back(Sample(fltVal*32767.0f, 0.0f));
 
     fltVal = m_objRunning.m_blnInvertVideo ? 1.0f - fltVal : fltVal;
 
@@ -640,7 +660,8 @@ bool ATVDemod::handleMessage(const Message& cmd)
                 << " m_fltRFOppBandwidth:" << m_objRFConfig.m_fltRFOppBandwidth
                 << " m_blnFFTFiltering:" << m_objRFConfig.m_blnFFTFiltering
                 << " m_blnDecimatorEnable:" << m_objRFConfig.m_blndecimatorEnable
-                << " m_fltBFOFrequency:" << m_objRFConfig.m_fltBFOFrequency;
+                << " m_fltBFOFrequency:" << m_objRFConfig.m_fltBFOFrequency
+                << " m_fmDeviation:" << m_objRFConfig.m_fmDeviation;
 
         applySettings();
 
@@ -761,6 +782,11 @@ void ATVDemod::applySettings()
         m_bfoFilter.setFrequencies(m_objRFConfig.m_fltBFOFrequency, m_objConfigPrivate.m_intTVSampleRate);
     }
 
+//    if (m_objRFConfig.m_fmDeviation != m_objRFRunning.m_fmDeviation)
+//    {
+//        m_objPhaseDiscri.setFMScaling(m_objRFConfig.m_fmDeviation);
+//    }
+
     m_objRunning = m_objConfig;
     m_objRFRunning = m_objRFConfig;
     m_objRunningPrivate = m_objConfigPrivate;

plugins/channelrx/demodatv/atvdemod.h

@@ -33,6 +33,7 @@
 #include "dsp/agc.h"
 #include "dsp/phaselock.h"
 #include "dsp/recursivefilters.h"
+#include "dsp/phasediscri.h"
 #include "audio/audiofifo.h"
 #include "util/message.h"
 #include "atvscreen.h"
@@ -47,6 +48,7 @@ public:
 	enum ATVModulation {
 	    ATV_FM1,  //!< Classical frequency modulation with discriminator #1
 	    ATV_FM2,  //!< Classical frequency modulation with discriminator #2
+	    ATV_FM3,  //!< Classical frequency modulation with phase derivative discriminator
         ATV_AM,   //!< Classical amplitude modulation
         ATV_USB,  //!< AM with vestigial lower side band (main signal is in the upper side)
         ATV_LSB   //!< AM with vestigial upper side band (main signal is in the lower side)
@@ -89,6 +91,7 @@ public:
         bool          m_blnFFTFiltering;
         bool          m_blndecimatorEnable;
         float         m_fltBFOFrequency;
+        float         m_fmDeviation;
 
         ATVRFConfig() :
             m_intFrequencyOffset(0),
@@ -97,7 +100,8 @@ public:
             m_fltRFOppBandwidth(0),
             m_blnFFTFiltering(false),
             m_blndecimatorEnable(false),
-            m_fltBFOFrequency(0.0f)
+            m_fltBFOFrequency(0.0f),
+            m_fmDeviation(1.0f)
         {
         }
     };
@@ -143,7 +147,8 @@ public:
             float fltRFOppBandwidth,
             bool blnFFTFiltering,
             bool blndecimatorEnable,
-            float fltBFOFrequency);
+            float fltBFOFrequency,
+            float fmDeviation);
 
 	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool po);
 	virtual void start();
@@ -232,7 +237,8 @@ private:
                     float fltRFOppBandwidth,
                     bool blnFFTFiltering,
                     bool blndecimatorEnable,
-                    int intBFOFrequency)
+                    int intBFOFrequency,
+                    float fmDeviation)
             {
                 return new MsgConfigureRFATVDemod(
                         enmModulation,
@@ -240,7 +246,8 @@ private:
                         fltRFOppBandwidth,
                         blnFFTFiltering,
                         blndecimatorEnable,
-                        intBFOFrequency);
+                        intBFOFrequency,
+                        fmDeviation);
             }
 
             ATVRFConfig m_objMsgConfig;
@@ -252,7 +259,8 @@ private:
                     float fltRFOppBandwidth,
                     bool blnFFTFiltering,
                     bool blndecimatorEnable,
-                    float fltBFOFrequency) :
+                    float fltBFOFrequency,
+                    float fmDeviation) :
                 Message()
             {
                 m_objMsgConfig.m_enmModulation = enmModulation;
@@ -261,6 +269,7 @@ private:
                 m_objMsgConfig.m_blnFFTFiltering = blnFFTFiltering;
                 m_objMsgConfig.m_blndecimatorEnable = blndecimatorEnable;
                 m_objMsgConfig.m_fltBFOFrequency = fltBFOFrequency;
+                m_objMsgConfig.m_fmDeviation = fmDeviation;
             }
     };
 
@@ -322,6 +331,9 @@ private:
     int m_DSBFilterBufferIndex;
     static const int m_ssbFftLen;
 
+    // Used for FM
+    PhaseDiscriminators m_objPhaseDiscri;
+
     //QElapsedTimer m_objTimer;
 
     ATVConfig m_objRunning;

plugins/channelrx/demodatv/atvdemodgui.cpp

@@ -92,6 +92,7 @@ void ATVDemodGUI::resetToDefaults()
     ui->rfBW->setValue(10);
     ui->rfOppBW->setValue(10);
     ui->bfo->setValue(0);
+    ui->fmDeviation->setValue(100);
 
     blockApplySettings(false);
     lineTimeUpdate();
@@ -118,6 +119,7 @@ QByteArray ATVDemodGUI::serialize() const
     s.writeS32(14, ui->bfo->value());
     s.writeBool(15, ui->invertVideo->isChecked());
     s.writeS32(16, ui->nbLines->currentIndex());
+    s.writeS32(17, ui->fmDeviation->value());
 
     return s.final();
 }
@@ -179,6 +181,8 @@ bool ATVDemodGUI::deserialize(const QByteArray& arrData)
         ui->invertVideo->setChecked(booltmp);
         d.readS32(16, &tmp, 0);
         ui->nbLines->setCurrentIndex(tmp);
+        d.readS32(17, &tmp, 100);
+        ui->fmDeviation->setValue(tmp);
 
         blockApplySettings(false);
         m_objChannelMarker.blockSignals(false);
@@ -322,6 +326,9 @@ ATVDemodGUI::ATVDemodGUI(PluginAPI* objPluginAPI, DeviceSourceAPI *objDeviceAPI,
     ui->scopeGUI->focusOnTrigger(0); // re-focus to take changes into account in the GUI
 
     connect(m_objATVDemod->getOutputMessageQueue(), SIGNAL(messageEnqueued()), this, SLOT(handleSourceMessages()));
+
+    QChar delta = QChar(0x94, 0x03);
+    ui->fmDeviationLabel->setText(delta);
 }
 
 ATVDemodGUI::~ATVDemodGUI()
@@ -378,7 +385,8 @@ void ATVDemodGUI::applyRFSettings()
                 ui->rfOppBW->value() * m_rfSliderDivisor * 1.0f,
                 ui->rfFiltering->isChecked(),
                 ui->decimatorEnable->isChecked(),
-                ui->bfo->value() * 10.0f);
+                ui->bfo->value() * 10.0f,
+                ui->fmDeviation->value() / 100.0f);
     }
 }
 
@@ -600,6 +608,12 @@ void ATVDemodGUI::on_bfo_valueChanged(int value)
     applyRFSettings();
 }
 
+void ATVDemodGUI::on_fmDeviation_valueChanged(int value)
+{
+    ui->fmDeviationText->setText(QString("%1").arg(value));
+    applyRFSettings();
+}
+
 void ATVDemodGUI::lineTimeUpdate()
 {
     float nominalLineTime = getNominalLineTime(ui->nbLines->currentIndex(), ui->fps->currentIndex());

plugins/channelrx/demodatv/atvdemodgui.h

@@ -83,6 +83,7 @@ private slots:
     void on_deltaFrequency_changed(quint64 value);
     void on_deltaFrequencyMinus_toggled(bool minus);
     void on_bfo_valueChanged(int value);
+    void on_fmDeviation_valueChanged(int value);
 
 private:
 	Ui::ATVDemodGUI* ui;

plugins/channelrx/demodatv/atvdemodgui.ui

@@ -40,7 +40,7 @@
      <x>10</x>
      <y>10</y>
      <width>681</width>
-     <height>81</height>
+     <height>83</height>
     </rect>
    </property>
    <property name="windowTitle">
@@ -275,6 +275,11 @@
           <string>FM 2</string>
          </property>
         </item>
+        <item>
+         <property name="text">
+          <string>FM 3</string>
+         </property>
+        </item>
         <item>
          <property name="text">
           <string>AM</string>
@@ -292,6 +297,58 @@
         </item>
        </widget>
       </item>
+      <item>
+       <widget class="QLabel" name="fmDeviationLabel">
+        <property name="text">
+         <string>D</string>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QDial" name="fmDeviation">
+        <property name="maximumSize">
+         <size>
+          <width>24</width>
+          <height>24</height>
+         </size>
+        </property>
+        <property name="minimum">
+         <number>1</number>
+        </property>
+        <property name="maximum">
+         <number>125</number>
+        </property>
+        <property name="pageStep">
+         <number>1</number>
+        </property>
+        <property name="value">
+         <number>100</number>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="fmDeviationText">
+        <property name="minimumSize">
+         <size>
+          <width>20</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="text">
+         <string>100</string>
+        </property>
+        <property name="alignment">
+         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="Line" name="line_4">
+        <property name="orientation">
+         <enum>Qt::Vertical</enum>
+        </property>
+       </widget>
+      </item>
       <item>
        <widget class="ButtonSwitch" name="rfFiltering">
         <property name="toolTip">

plugins/channelrx/demodnfm/nfmdemod.cpp

@@ -156,7 +156,7 @@ void NFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVecto
 				//m_AGC.feed(ci);
 
                 //double magsqRaw = m_AGC.getMagSq();
-				long double magsqRaw; // = ci.real()*ci.real() + c.imag()*c.imag();
+				double magsqRaw; // = ci.real()*ci.real() + c.imag()*c.imag();
 				Real deviation;
 
 				Real demod = m_phaseDiscri.phaseDiscriminatorDelta(ci, magsqRaw, deviation);

sdrbase/dsp/phasediscri.h

@@ -55,7 +55,7 @@ public:
      * Discriminator with phase detection using atan2 and frequency by derivation.
      * This yields a precise deviation to sample rate ratio: Sample rate => +/-1.0
      */
-    Real phaseDiscriminatorDelta(const Complex& sample, long double& magsq, Real& fmDev)
+    Real phaseDiscriminatorDelta(const Complex& sample, double& magsq, Real& fmDev)
     {
         Real fltI = sample.real();
         Real fltQ = sample.imag();