NFM demod: added adjustable squelch gate time (AGC attack) to adjust the length of transient elimination from default 50ms

plugins/channel/demodnfm/nfmdemod.cpp

@@ -48,6 +48,7 @@ NFMDemod::NFMDemod() :
 	m_config.m_inputFrequencyOffset = 0;
 	m_config.m_rfBandwidth = 12500;
 	m_config.m_afBandwidth = 3000;
+	m_config.m_squelchGate = 5; // 10s of ms at 48000 Hz sample rate. Corresponds to 2400 for AGC attack
 	m_config.m_squelch = -30.0;
 	m_config.m_volume = 1.0;
 	m_config.m_ctcssOn = false;
@@ -78,6 +79,7 @@ void NFMDemod::configure(MessageQueue* messageQueue,
 		Real rfBandwidth,
 		Real afBandwidth,
 		Real volume,
+		int  squelchGate,
 		Real squelch,
 		bool ctcssOn,
 		bool audioMute)
@@ -85,6 +87,7 @@ void NFMDemod::configure(MessageQueue* messageQueue,
 	Message* cmd = MsgConfigureNFMDemod::create(rfBandwidth,
 			afBandwidth,
 			volume,
+			squelchGate,
 			squelch,
 			ctcssOn,
 			audioMute);
@@ -295,6 +298,7 @@ bool NFMDemod::handleMessage(const Message& cmd)
 		m_config.m_rfBandwidth = cfg.getRFBandwidth();
 		m_config.m_afBandwidth = cfg.getAFBandwidth();
 		m_config.m_volume = cfg.getVolume();
+		m_config.m_squelchGate = cfg.getSquelchGate();
 		m_config.m_squelch = cfg.getSquelch();
 		m_config.m_ctcssOn = cfg.getCtcssOn();
 		m_config.m_audioMute = cfg.getAudioMute();
@@ -304,6 +308,7 @@ bool NFMDemod::handleMessage(const Message& cmd)
 		qDebug() << "NFMDemod::handleMessage: MsgConfigureNFMDemod: m_rfBandwidth: " << m_config.m_rfBandwidth
 				<< " m_afBandwidth: " << m_config.m_afBandwidth
 				<< " m_volume: " << m_config.m_volume
+				<< " m_squelchGate" << m_config.m_squelchGate
 				<< " m_squelch: " << m_config.m_squelch
 				<< " m_ctcssOn: " << m_config.m_ctcssOn
 				<< " m_audioMute: " << m_config.m_audioMute;
@@ -345,6 +350,12 @@ void NFMDemod::apply()
 		m_settingsMutex.unlock();
 	}
 
+	if (m_config.m_squelchGate != m_running.m_squelchGate)
+	{
+		m_agcAttack = 480 * m_config.m_squelchGate; // gate is given in 10s of ms at 48000 Hz audio sample rate
+		m_AGC.resize(m_agcAttack, m_agcLevel);
+	}
+
 	if (m_config.m_squelch != m_running.m_squelch)
 	{
 		// input is a value in tenths of dB
@@ -357,6 +368,7 @@ void NFMDemod::apply()
 	m_running.m_inputFrequencyOffset = m_config.m_inputFrequencyOffset;
 	m_running.m_rfBandwidth = m_config.m_rfBandwidth;
 	m_running.m_afBandwidth = m_config.m_afBandwidth;
+	m_running.m_squelchGate = m_config.m_squelchGate;
 	m_running.m_squelch = m_config.m_squelch;
 	m_running.m_volume = m_config.m_volume;
 	m_running.m_audioSampleRate = m_config.m_audioSampleRate;

plugins/channel/demodnfm/nfmdemod.h

@@ -44,6 +44,7 @@ public:
 			Real rfBandwidth,
 			Real afBandwidth,
 			Real volume,
+			int  squelchGate,
 			Real squelch,
 			bool ctcssOn,
 			bool audioMute);
@@ -76,7 +77,8 @@ private:
 	public:
 		Real getRFBandwidth() const { return m_rfBandwidth; }
 		Real getAFBandwidth() const { return m_afBandwidth; }
-		Real getVolume() const { return m_volume; }
+		Real getVolume() const { return m_volume; }\
+		int  getSquelchGate() const { return m_squelchGate; }
 		Real getSquelch() const { return m_squelch; }
 		bool getCtcssOn() const { return m_ctcssOn; }
 		bool getAudioMute() const { return m_audioMute; }
@@ -84,17 +86,19 @@ private:
 		static MsgConfigureNFMDemod* create(Real rfBandwidth,
 				Real afBandwidth,
 				Real volume,
+				int  squelchGate,
 				Real squelch,
 				bool ctcssOn,
 				bool audioMute)
 		{
-			return new MsgConfigureNFMDemod(rfBandwidth, afBandwidth, volume, squelch, ctcssOn, audioMute);
+			return new MsgConfigureNFMDemod(rfBandwidth, afBandwidth, volume, squelchGate, squelch, ctcssOn, audioMute);
 		}
 
 	private:
 		Real m_rfBandwidth;
 		Real m_afBandwidth;
 		Real m_volume;
+		int  m_squelchGate;
 		Real m_squelch;
 		bool m_ctcssOn;
 		bool m_audioMute;
@@ -102,6 +106,7 @@ private:
 		MsgConfigureNFMDemod(Real rfBandwidth,
 				Real afBandwidth,
 				Real volume,
+				int  squelchGate,
 				Real squelch,
 				bool ctcssOn,
 				bool audioMute) :
@@ -109,6 +114,7 @@ private:
 			m_rfBandwidth(rfBandwidth),
 			m_afBandwidth(afBandwidth),
 			m_volume(volume),
+			m_squelchGate(squelchGate),
 			m_squelch(squelch),
 			m_ctcssOn(ctcssOn),
 			m_audioMute(audioMute)
@@ -131,6 +137,7 @@ private:
 		qint64 m_inputFrequencyOffset;
 		Real m_rfBandwidth;
 		Real m_afBandwidth;
+		int  m_squelchGate;
 		Real m_squelch;
 		Real m_volume;
 		bool m_ctcssOn;
@@ -143,6 +150,7 @@ private:
 			m_inputFrequencyOffset(0),
 			m_rfBandwidth(-1),
 			m_afBandwidth(-1),
+			m_squelchGate(50),
 			m_squelch(0),
 			m_volume(0),
 			m_ctcssOn(false),

plugins/channel/demodnfm/nfmdemodgui.cpp

@@ -57,6 +57,7 @@ void NFMDemodGUI::resetToDefaults()
 	ui->rfBW->setValue(4);
 	ui->afBW->setValue(3);
 	ui->volume->setValue(20);
+	ui->squelchGate->setValue(5);
 	ui->squelch->setValue(-40);
 	ui->deltaFrequency->setValue(0);
 	ui->ctcssOn->setChecked(false);
@@ -78,6 +79,7 @@ QByteArray NFMDemodGUI::serialize() const
 	s.writeS32(8, ui->ctcss->currentIndex());
 	s.writeBool(9, ui->ctcssOn->isChecked());
 	s.writeBool(10, ui->audioMute->isChecked());
+	s.writeS32(11, ui->squelchGate->value());
 	return s.final();
 }
 
@@ -123,6 +125,8 @@ bool NFMDemodGUI::deserialize(const QByteArray& data)
 		ui->ctcssOn->setChecked(boolTmp);
 		d.readBool(10, &boolTmp, false);
 		ui->audioMute->setChecked(boolTmp);
+		d.readS32(11, &tmp, 5);
+		ui->squelchGate->setValue(tmp);
 
 		blockApplySettings(false);
 		m_channelMarker.blockSignals(false);
@@ -189,6 +193,12 @@ void NFMDemodGUI::on_volume_valueChanged(int value)
 	applySettings();
 }
 
+void NFMDemodGUI::on_squelchGate_valueChanged(int value)
+{
+	ui->squelchGateText->setText(QString("%1").arg(value * 10.0, 0, 'f', 0));
+	applySettings();
+}
+
 void NFMDemodGUI::on_squelch_valueChanged(int value)
 {
 	ui->squelchText->setText(QString("%1").arg(value / 10.0, 0, 'f', 1));
@@ -312,6 +322,7 @@ void NFMDemodGUI::applySettings()
 			m_rfBW[ui->rfBW->value()],
 			ui->afBW->value() * 1000.0,
 			ui->volume->value() / 10.0,
+			ui->squelchGate->value(), // in 10ths of ms
 			ui->squelch->value(),
 			ui->ctcssOn->isChecked(),
 			ui->audioMute->isChecked());

plugins/channel/demodnfm/nfmdemodgui.h

@@ -43,6 +43,7 @@ private slots:
 	void on_rfBW_valueChanged(int value);
 	void on_afBW_valueChanged(int value);
 	void on_volume_valueChanged(int value);
+	void on_squelchGate_valueChanged(int value);
 	void on_squelch_valueChanged(int value);
 	void on_ctcss_currentIndexChanged(int index);
 	void on_ctcssOn_toggled(bool checked);

plugins/channel/demodnfm/nfmdemodgui.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>281</width>
+    <width>279</width>
-    <height>162</height>
+    <height>172</height>
    </rect>
   </property>
   <property name="font">
@@ -25,7 +25,7 @@
      <x>0</x>
      <y>0</y>
      <width>271</width>
-     <height>131</height>
+     <height>161</height>
     </rect>
    </property>
    <property name="windowTitle">
@@ -243,7 +243,7 @@
       <item>
        <widget class="QLabel" name="volumeLabel">
         <property name="text">
-         <string>Volume</string>
+         <string>Vol</string>
         </property>
        </widget>
       </item>
@@ -289,14 +289,14 @@
       <item>
        <widget class="QLabel" name="squelchLabel">
         <property name="text">
-         <string>Squelch</string>
+         <string>Sq</string>
         </property>
        </widget>
       </item>
       <item>
        <widget class="QSlider" name="squelch">
         <property name="toolTip">
-         <string>Squelch</string>
+         <string>Squelch threshold (dB)</string>
         </property>
         <property name="minimum">
          <number>-1000</number>
@@ -323,6 +323,9 @@
           <height>0</height>
          </size>
         </property>
+        <property name="toolTip">
+         <string>Squelch threshold (dB)</string>
+        </property>
         <property name="text">
          <string>-15.0</string>
         </property>
@@ -331,6 +334,53 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QDial" name="squelchGate">
+        <property name="maximumSize">
+         <size>
+          <width>24</width>
+          <height>24</height>
+         </size>
+        </property>
+        <property name="toolTip">
+         <string>Squelch gate (ms)</string>
+        </property>
+        <property name="minimum">
+         <number>1</number>
+        </property>
+        <property name="maximum">
+         <number>50</number>
+        </property>
+        <property name="pageStep">
+         <number>1</number>
+        </property>
+        <property name="value">
+         <number>5</number>
+        </property>
+        <property name="sliderPosition">
+         <number>5</number>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="squelchGateText">
+        <property name="minimumSize">
+         <size>
+          <width>25</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="toolTip">
+         <string>Squelch gate (ms)</string>
+        </property>
+        <property name="text">
+         <string>000</string>
+        </property>
+        <property name="alignment">
+         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+        </property>
+       </widget>
+      </item>
      </layout>
     </item>
     <item>

sdrbase/gui/aboutdialog.ui

@@ -84,7 +84,7 @@
    <item>
     <widget class="QLabel" name="label_2">
      <property name="text">
-      <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Version 1.1.5 - Copyright (C) 2015-2016 Edouard Griffiths, F4EXB. &lt;/p&gt;&lt;p&gt;Code at &lt;a href=&quot;https://github.com/f4exb/sdrangel&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;https://github.com/f4exb/sdrangel&lt;/span&gt;&lt;/a&gt; This is a complete redesign from RTL-SDRangelove at &lt;a href=&quot;https://github.com/hexameron/rtl-sdrangelove&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;https://github.com/hexameron/rtl-sdrangelove&lt;/span&gt;&lt;/a&gt;&lt;/p&gt;&lt;p&gt;Many thanks to the original developers:&lt;/p&gt;&lt;p&gt;The osmocom developer team - especially horizon, Hoernchen &amp;amp; tnt.&lt;/p&gt;&lt;p&gt;Christian Daniel from maintech GmbH.&lt;/p&gt;&lt;p&gt;John Greb (hexameron) for the contributions in RTL-SDRangelove&lt;/p&gt;&lt;p&gt;The following rules apply to the SDRangel main application and libsdrbase:&lt;br/&gt;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 2 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. You should have received a copy of the GNU General Public License along with this program. If not, see &lt;a href=&quot;http://www.gnu.org/licenses/&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;http://www.gnu.org/licenses/&lt;/span&gt;&lt;/a&gt;.&lt;/p&gt;&lt;p&gt;For the license of installed plugins, look into the plugin list.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+      <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Version 1.1.6 - Copyright (C) 2015-2016 Edouard Griffiths, F4EXB. &lt;/p&gt;&lt;p&gt;Code at &lt;a href=&quot;https://github.com/f4exb/sdrangel&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;https://github.com/f4exb/sdrangel&lt;/span&gt;&lt;/a&gt; This is a complete redesign from RTL-SDRangelove at &lt;a href=&quot;https://github.com/hexameron/rtl-sdrangelove&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;https://github.com/hexameron/rtl-sdrangelove&lt;/span&gt;&lt;/a&gt;&lt;/p&gt;&lt;p&gt;Many thanks to the original developers:&lt;/p&gt;&lt;p&gt;The osmocom developer team - especially horizon, Hoernchen &amp;amp; tnt.&lt;/p&gt;&lt;p&gt;Christian Daniel from maintech GmbH.&lt;/p&gt;&lt;p&gt;John Greb (hexameron) for the contributions in RTL-SDRangelove&lt;/p&gt;&lt;p&gt;The following rules apply to the SDRangel main application and libsdrbase:&lt;br/&gt;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 2 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. You should have received a copy of the GNU General Public License along with this program. If not, see &lt;a href=&quot;http://www.gnu.org/licenses/&quot;&gt;&lt;span style=&quot; text-decoration: underline; color:#0000ff;&quot;&gt;http://www.gnu.org/licenses/&lt;/span&gt;&lt;/a&gt;.&lt;/p&gt;&lt;p&gt;For the license of installed plugins, look into the plugin list.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
      </property>
      <property name="wordWrap">
       <bool>true</bool>