From f56bea2afeb27184dd4c13127c918d45d8ab9dcd Mon Sep 17 00:00:00 2001
From: f4exb <f4exb06@gmail.com>
Date: Sun, 20 Aug 2017 23:44:40 +0200
Subject: [PATCH] UDP source plugin: optimize squelch gate and release times
 for SSB

---
 plugins/channelrx/udpsrc/udpsrc.cpp   | 34 +++++++++++++++++++++++----
 plugins/channelrx/udpsrc/udpsrc.h     | 15 ++++++------
 plugins/channelrx/udpsrc/udpsrcgui.ui |  2 +-
 3 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/plugins/channelrx/udpsrc/udpsrc.cpp b/plugins/channelrx/udpsrc/udpsrc.cpp
index a878fd759..a0a10f70b 100644
--- a/plugins/channelrx/udpsrc/udpsrc.cpp
+++ b/plugins/channelrx/udpsrc/udpsrc.cpp
@@ -37,7 +37,8 @@ UDPSrc::UDPSrc(MessageQueue* uiMessageQueue, UDPSrcGUI* udpSrcGUI, BasebandSampl
     m_squelchOpen(false),
     m_squelchOpenCount(0),
     m_squelchCloseCount(0),
-    m_squelchThreshold(4800),
+    m_squelchGate(4800),
+    m_squelchRelease(4800),
     m_agc(9600, m_agcTarget, 1e-6),
     m_settingsMutex(QMutex::Recursive)
 {
@@ -448,11 +449,23 @@ void UDPSrc::apply(bool force)
         m_interpolator.create(16, m_config.m_inputSampleRate, m_config.m_rfBandwidth / 2.0);
         m_sampleDistanceRemain = m_config.m_inputSampleRate / m_config.m_outputSampleRate;
 
-        m_squelchThreshold = m_config.m_outputSampleRate * m_config.m_squelchGate;
+        if ((m_config.m_sampleFormat == FormatLSB) ||
+            (m_config.m_sampleFormat == FormatLSBMono) ||
+            (m_config.m_sampleFormat == FormatUSB) ||
+            (m_config.m_sampleFormat == FormatUSBMono))
+        {
+            m_squelchGate = m_config.m_outputSampleRate * 0.05;
+        }
+        else
+        {
+            m_squelchGate = m_config.m_outputSampleRate * m_config.m_squelchGate;
+        }
+
+        m_squelchRelease = m_config.m_outputSampleRate * m_config.m_squelchGate;
         initSquelch(m_squelchOpen);
         m_agc.resize(m_config.m_outputSampleRate * 0.2, m_agcTarget); // Fixed 200 ms
         m_agc.setStepDownDelay( m_config.m_outputSampleRate * (m_config.m_squelchGate == 0 ? 0.01 : m_config.m_squelchGate));
-        m_agc.setGate(m_config.m_outputSampleRate * 0.02);
+        m_agc.setGate(m_config.m_outputSampleRate * 0.05);
 
         m_bandpass.create(301, m_config.m_outputSampleRate, 300.0, m_config.m_rfBandwidth / 2.0f);
 
@@ -476,10 +489,21 @@ void UDPSrc::apply(bool force)
 
     if ((m_config.m_squelchGate != m_running.m_squelchGate) || force)
     {
-        m_squelchThreshold = m_config.m_outputSampleRate * m_config.m_squelchGate;
+        if ((m_config.m_sampleFormat == FormatLSB) ||
+            (m_config.m_sampleFormat == FormatLSBMono) ||
+            (m_config.m_sampleFormat == FormatUSB) ||
+            (m_config.m_sampleFormat == FormatUSBMono))
+        {
+            m_squelchGate = m_config.m_outputSampleRate * 0.05;
+        }
+        else
+        {
+            m_squelchGate = m_config.m_outputSampleRate * m_config.m_squelchGate;
+        }
+
+        m_squelchRelease = m_config.m_outputSampleRate * m_config.m_squelchGate;
         initSquelch(m_squelchOpen);
         m_agc.setStepDownDelay(m_config.m_outputSampleRate * (m_config.m_squelchGate == 0 ? 0.01 : m_config.m_squelchGate)); // same delay for up and down
-        m_agc.setGate(m_config.m_outputSampleRate * 0.02);
     }
 
     if ((m_config.m_squelch != m_running.m_squelch) || force)
diff --git a/plugins/channelrx/udpsrc/udpsrc.h b/plugins/channelrx/udpsrc/udpsrc.h
index 3f5257274..5a49aba84 100644
--- a/plugins/channelrx/udpsrc/udpsrc.h
+++ b/plugins/channelrx/udpsrc/udpsrc.h
@@ -340,7 +340,8 @@ protected:
     bool m_squelchOpen;
     int  m_squelchOpenCount;
     int  m_squelchCloseCount;
-    int m_squelchThreshold; //!< number of samples computed from given gate
+    int  m_squelchGate; //!< number of samples computed from given gate
+    int  m_squelchRelease;
 
     MagAGC m_agc;
     Bandpass<double> m_bandpass;
@@ -353,26 +354,26 @@ protected:
     {
         if ((!m_running.m_squelchEnabled) || (value > m_running.m_squelch))
         {
-            if (m_squelchThreshold == 0)
+            if (m_squelchGate == 0)
             {
                 m_squelchOpen = true;
             }
             else
             {
-                if (m_squelchOpenCount < m_squelchThreshold)
+                if (m_squelchOpenCount < m_squelchGate)
                 {
                     m_squelchOpenCount++;
                 }
                 else
                 {
-                    m_squelchCloseCount = m_squelchThreshold;
+                    m_squelchCloseCount = m_squelchRelease;
                     m_squelchOpen = true;
                 }
             }
         }
         else
         {
-            if (m_squelchThreshold == 0)
+            if (m_squelchGate == 0)
             {
                 m_squelchOpen = false;
             }
@@ -396,8 +397,8 @@ protected:
         if (open)
         {
             m_squelchOpen = true;
-            m_squelchOpenCount = m_squelchThreshold;
-            m_squelchCloseCount = m_squelchThreshold;
+            m_squelchOpenCount = m_squelchGate;
+            m_squelchCloseCount = m_squelchRelease;
         }
         else
         {
diff --git a/plugins/channelrx/udpsrc/udpsrcgui.ui b/plugins/channelrx/udpsrc/udpsrcgui.ui
index 5daae8808..f53605430 100644
--- a/plugins/channelrx/udpsrc/udpsrcgui.ui
+++ b/plugins/channelrx/udpsrc/udpsrcgui.ui
@@ -641,7 +641,7 @@
          <string>Squelch gate (ms)</string>
         </property>
         <property name="maximum">
-         <number>50</number>
+         <number>90</number>
         </property>
         <property name="pageStep">
          <number>1</number>