FT8 demod: volume meter

plugins/channelrx/demodft8/ft8demod.h

@@ -136,6 +136,9 @@ public:
             SWGSDRangel::SWGChannelSettings& response);
 
     uint32_t getNumberOfDeviceStreams() const;
+    void setLevelMeter(QObject *levelMeter) {
+        connect(m_basebandSink, SIGNAL(levelChanged(qreal, qreal, int)), levelMeter, SLOT(levelChanged(qreal, qreal, int)));
+    }
 
     static const char* const m_channelIdURI;
     static const char* const m_channelId;

plugins/channelrx/demodft8/ft8demodbaseband.cpp

@@ -94,6 +94,11 @@ void FT8DemodBaseband::handleData()
 
 		m_sampleFifo.readCommit((unsigned int) count);
     }
+
+    qreal rmsLevel, peakLevel;
+    int numSamples;
+    m_sink.getLevels(rmsLevel, peakLevel, numSamples);
+    emit levelChanged(rmsLevel, peakLevel, numSamples);
 }
 
 void FT8DemodBaseband::handleInputMessages()

plugins/channelrx/demodft8/ft8demodbaseband.h

@@ -75,6 +75,15 @@ public:
     void setFifoLabel(const QString& label) { m_sampleFifo.setLabel(label); }
     void setAudioFifoLabel(const QString& label) { m_sink.setAudioFifoLabel(label); }
 
+signals:
+	/**
+	 * Level changed
+	 * \param rmsLevel RMS level in range 0.0 - 1.0
+	 * \param peakLevel Peak level in range 0.0 - 1.0
+	 * \param numSamples Number of samples analyzed
+	 */
+	void levelChanged(qreal rmsLevel, qreal peakLevel, int numSamples);
+
 private:
     SampleSinkFifo m_sampleFifo;
     DownChannelizer m_channelizer;

plugins/channelrx/demodft8/ft8demodgui.cpp

@@ -324,6 +324,7 @@ FT8DemodGUI::FT8DemodGUI(PluginAPI* pluginAPI, DeviceUISet *deviceUISet, Baseban
     connect(getInputMessageQueue(), SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
 
 	ui->spectrumGUI->setBuddies(m_spectrumVis, ui->glSpectrum);
+    m_ft8Demod->setLevelMeter(ui->volumeMeter);
 
     ui->BW->setMaximum(60);
     ui->BW->setMinimum(10);

plugins/channelrx/demodft8/ft8demodgui.ui

@@ -635,24 +635,29 @@
        </widget>
       </item>
       <item>
-       <widget class="Line" name="line_2">
+       <widget class="LevelMeterVU" name="volumeMeter" native="true">
-        <property name="orientation">
+        <property name="sizePolicy">
-         <enum>Qt::Vertical</enum>
+         <sizepolicy hsizetype="MinimumExpanding" vsizetype="Preferred">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
         </property>
-       </widget>
+        <property name="minimumSize">
-      </item>
-      <item>
-       <spacer name="horizontalSpacer">
-        <property name="orientation">
-         <enum>Qt::Horizontal</enum>
-        </property>
-        <property name="sizeHint" stdset="0">
          <size>
-          <width>40</width>
+          <width>140</width>
-          <height>20</height>
+          <height>24</height>
          </size>
         </property>
-       </spacer>
+        <property name="font">
+         <font>
+          <family>Liberation Mono</family>
+          <pointsize>8</pointsize>
+         </font>
+        </property>
+        <property name="toolTip">
+         <string>Modem input volume</string>
+        </property>
+       </widget>
       </item>
      </layout>
     </item>
@@ -774,6 +779,12 @@
    <extends>QSlider</extends>
    <header>gui/tickedslider.h</header>
   </customwidget>
+  <customwidget>
+   <class>LevelMeterVU</class>
+   <extends>QWidget</extends>
+   <header>gui/levelmeter.h</header>
+   <container>1</container>
+  </customwidget>
  </customwidgets>
  <resources>
   <include location="../../../sdrgui/resources/res.qrc"/>

plugins/channelrx/demodft8/ft8demodsink.cpp

@@ -36,13 +36,39 @@
 const int FT8DemodSink::m_ssbFftLen = 1024;
 const int FT8DemodSink::m_agcTarget = 3276; // 32768/10 -10 dB amplitude => -20 dB power: center of normal signal
 
+FT8DemodSink::LevelRMS::LevelRMS()
+{
+    m_sum = 0.0f;
+    m_peak = 0.0f;
+    m_n = 0;
+    m_reset = true;
+}
+
+void FT8DemodSink::LevelRMS::accumulate(float level)
+{
+    if (m_reset)
+    {
+        m_sum = level * level;
+        m_peak = std::fabs(level);
+        m_n = 1;
+        m_reset = false;
+    }
+    else
+    {
+        m_sum += level * level;
+        m_peak = std::max(m_peak, std::fabs(level));
+        m_n++;
+    }
+}
+
 FT8DemodSink::FT8DemodSink() :
         m_agc(12000, m_agcTarget, 1e-2),
         m_agcActive(false),
         m_audioActive(false),
         m_spectrumSink(nullptr),
         m_audioFifo(24000),
-        m_ft8SampleRate(12000)
+        m_ft8SampleRate(12000),
+        m_levelInNbSamples(1200) // 100 ms
 {
 	m_Bandwidth = 5000;
 	m_LowCutoff = 300;
@@ -155,6 +181,7 @@ void FT8DemodSink::processOneSample(Complex &ci)
         m_audioBuffer[m_audioBufferFill].l = sample;
         m_audioBuffer[m_audioBufferFill].r = sample;
         m_demodBuffer[m_demodBufferFill++] = sample;
+        calculateLevel(sample);
 
         if (m_demodBufferFill >= m_demodBuffer.size())
         {
@@ -241,6 +268,7 @@ void FT8DemodSink::applyFT8SampleRate(int sampleRate)
 
     m_audioFifo.setSize(sampleRate);
     m_ft8SampleRate = sampleRate;
+    m_levelInNbSamples = m_ft8SampleRate / 10; // 100 ms
 
     QList<ObjectPipe*> pipes;
     MainCore::instance()->getMessagePipes().getMessagePipes(m_channel, "reportdemod", pipes);
@@ -324,3 +352,14 @@ void FT8DemodSink::applySettings(const FT8DemodSettings& settings, bool force)
     m_settings = settings;
 }
 
+void FT8DemodSink::calculateLevel(int16_t& sample)
+{
+    if (m_levelIn.m_n >= m_levelInNbSamples)
+    {
+        m_rmsLevel = sqrt(m_levelIn.m_sum / m_levelInNbSamples);
+        m_peakLevel = m_levelIn.m_peak;
+        m_levelIn.m_reset = true;
+    }
+
+    m_levelIn.accumulate(sample/29491.2f); // scale on 90% (0.9 * 32768.0)
+}

plugins/channelrx/demodft8/ft8demodsink.h

@@ -69,6 +69,19 @@ public:
         m_magsqCount = 0;
     }
 
+	/**
+	 * Level changed
+	 * \param rmsLevel RMS level in range 0.0 - 1.0
+	 * \param peakLevel Peak level in range 0.0 - 1.0
+	 * \param numSamples Number of samples analyzed
+	 */
+	void getLevels(qreal& rmsLevel, qreal& peakLevel, int& numSamples)
+    {
+        rmsLevel = m_rmsLevel;
+        peakLevel = m_peakLevel;
+        numSamples = m_levelInNbSamples;
+    }
+
 private:
     struct MagSqLevelsStore
     {
@@ -80,6 +93,17 @@ private:
         double m_magsqPeak;
     };
 
+	struct LevelRMS
+	{
+		LevelRMS();
+		void accumulate(float fsample);
+
+		double m_sum;
+		float m_peak;
+		int m_n;
+		bool m_reset;
+	};
+
     FT8DemodSettings m_settings;
     ChannelAPI *m_channel;
 
@@ -118,10 +142,16 @@ private:
     QVector<qint16> m_demodBuffer;
     int m_demodBufferFill;
 
+    LevelRMS m_levelIn;
+	int m_levelInNbSamples;
+    Real m_rmsLevel;
+    Real m_peakLevel;
+
 	static const int m_ssbFftLen;
 	static const int m_agcTarget;
 
     void processOneSample(Complex &ci);
+    void calculateLevel(int16_t& sample);
 };
 
 #endif // INCLUDE_FT8DEMODSINK_H