Support Video Source & Setting Changes Runtime

For Video Streaming usecase, QGroundControl doesnt support changing of
Video Source or URI settings. Restart of QGroundControl application was
required for the changes to get applied. The issue is now resolved by
restarting the video receiver pipeline with new video source/setting.
Signed-off-by: lbegani <lalit.kumar.begani@intel.com>

src/FlightDisplay/VideoManager.cc

@@ -57,6 +57,9 @@ VideoManager::setToolbox(QGCToolbox *toolbox)
    _videoSettings = toolbox->settingsManager()->videoSettings();
    QString videoSource = _videoSettings->videoSource()->rawValue().toString();
    connect(_videoSettings->videoSource(), &Fact::rawValueChanged, this, &VideoManager::_videoSourceChanged);
+   connect(_videoSettings->udpPort(), &Fact::rawValueChanged, this, &VideoManager::_udpPortChanged);
+   connect(_videoSettings->rtspUrl(), &Fact::rawValueChanged, this, &VideoManager::_rtspUrlChanged);
+
 
 #if defined(QGC_GST_STREAMING)
 #ifndef QGC_DISABLE_UVC
@@ -96,6 +99,17 @@ void VideoManager::_videoSourceChanged(void)
 {
     emit hasVideoChanged();
     emit isGStreamerChanged();
+    _restartVideo();
+}
+
+void VideoManager::_udpPortChanged(void)
+{
+    _restartVideo();
+}
+
+void VideoManager::_rtspUrlChanged(void)
+{
+    _restartVideo();
 }
 
 //-----------------------------------------------------------------------------
@@ -170,6 +184,18 @@ void VideoManager::_updateTimer()
 #endif
 }
 
+//-----------------------------------------------------------------------------
+void VideoManager::_updateSettings()
+{
+    if(!_videoSettings || !_videoReceiver)
+        return;
+
+    if (_videoSettings->videoSource()->rawValue().toString() == VideoSettings::videoSourceUDP)
+        _videoReceiver->setUri(QStringLiteral("udp://0.0.0.0:%1").arg(_videoSettings->udpPort()->rawValue().toInt()));
+    else
+        _videoReceiver->setUri(_videoSettings->rtspUrl()->rawValue().toString());
+}
+
 //-----------------------------------------------------------------------------
 void VideoManager::_updateVideo()
 {
@@ -182,12 +208,20 @@ void VideoManager::_updateVideo()
         _videoReceiver = new VideoReceiver(this);
 #if defined(QGC_GST_STREAMING)
         _videoReceiver->setVideoSink(_videoSurface->videoSink());
-        QString videoSource = _videoSettings->videoSource()->rawValue().toString();
-        if (_videoSettings->videoSource()->rawValue().toString() == VideoSettings::videoSourceUDP)
-            _videoReceiver->setUri(QStringLiteral("udp://0.0.0.0:%1").arg(_videoSettings->udpPort()->rawValue().toInt()));
-        else
-            _videoReceiver->setUri(_videoSettings->rtspUrl()->rawValue().toString());
+        _updateSettings();
 #endif
         _videoReceiver->start();
     }
 }
+
+//-----------------------------------------------------------------------------
+void VideoManager::_restartVideo()
+{
+    if(!_videoReceiver)
+        return;
+#if defined(QGC_GST_STREAMING)
+    _videoReceiver->stop();
+    _updateSettings();
+    _videoReceiver->start();
+#endif
+}

src/FlightDisplay/VideoManager.h

@@ -69,10 +69,16 @@ signals:
 
 private slots:
     void _videoSourceChanged(void);
+    void _udpPortChanged(void);
+    void _rtspUrlChanged(void);
+
 
 private:
     void _updateTimer           ();
+    void _updateSettings        ();
     void _updateVideo           ();
+    void _restartVideo          ();
+
 
     VideoSurface*   _videoSurface;
     VideoReceiver*  _videoReceiver;

src/ui/preferences/GeneralSettings.qml

@@ -495,7 +495,7 @@ QGCView {
                     visible:                    QGroundControl.settingsManager.videoSettings.visible
                     QGCLabel {
                         id:             videoLabel
-                        text:           qsTr("Video (Requires Restart)")
+                        text:           qsTr("Video")
                         font.family:    ScreenTools.demiboldFontFamily
                     }
                 }