Make sure video streaming is running before accessing the video receiver.

src/Camera/QGCCameraControl.cc

@@ -364,10 +364,12 @@ QGCCameraControl::takePhoto()
             _setPhotoStatus(PHOTO_CAPTURE_IN_PROGRESS);
             _captureInfoRetries = 0;
             //-- Capture local image as well
-            QString photoPath = qgcApp()->toolbox()->settingsManager()->appSettings()->savePath()->rawValue().toString() + QStringLiteral("/Photo");
-            QDir().mkpath(photoPath);
-            photoPath += + "/" + QDateTime::currentDateTime().toString("yyyy-MM-dd_hh.mm.ss.zzz") + ".jpg";
-            qgcApp()->toolbox()->videoManager()->videoReceiver()->grabImage(photoPath);
+            if(qgcApp()->toolbox()->videoManager()->videoReceiver()) {
+                QString photoPath = qgcApp()->toolbox()->settingsManager()->appSettings()->savePath()->rawValue().toString() + QStringLiteral("/Photo");
+                QDir().mkpath(photoPath);
+                photoPath += + "/" + QDateTime::currentDateTime().toString("yyyy-MM-dd_hh.mm.ss.zzz") + ".jpg";
+                qgcApp()->toolbox()->videoManager()->videoReceiver()->grabImage(photoPath);
+            }
             return true;
         }
     }
@@ -1471,10 +1473,12 @@ QGCCameraControl::handleCaptureStatus(const mavlink_camera_capture_status_t& cap
     //-- Time Lapse
     if(photoStatus() == PHOTO_CAPTURE_INTERVAL_IDLE || photoStatus() == PHOTO_CAPTURE_INTERVAL_IN_PROGRESS) {
         //-- Capture local image as well
-        QString photoPath = qgcApp()->toolbox()->settingsManager()->appSettings()->savePath()->rawValue().toString() + QStringLiteral("/Photo");
-        QDir().mkpath(photoPath);
-        photoPath += + "/" + QDateTime::currentDateTime().toString("yyyy-MM-dd_hh.mm.ss.zzz") + ".jpg";
-        qgcApp()->toolbox()->videoManager()->videoReceiver()->grabImage(photoPath);
+        if(qgcApp()->toolbox()->videoManager()->videoReceiver()) {
+            QString photoPath = qgcApp()->toolbox()->settingsManager()->appSettings()->savePath()->rawValue().toString() + QStringLiteral("/Photo");
+            QDir().mkpath(photoPath);
+            photoPath += + "/" + QDateTime::currentDateTime().toString("yyyy-MM-dd_hh.mm.ss.zzz") + ".jpg";
+            qgcApp()->toolbox()->videoManager()->videoReceiver()->grabImage(photoPath);
+        }
     }
 }
 

src/Vehicle/Vehicle.cc

@@ -1640,9 +1640,11 @@ void Vehicle::_updateArmed(bool armed)
         } else {
             _mapTrajectoryStop();
             // Also handle Video Streaming
-            if(_settingsManager->videoSettings()->disableWhenDisarmed()->rawValue().toBool()) {
-                _settingsManager->videoSettings()->streamEnabled()->setRawValue(false);
-                qgcApp()->toolbox()->videoManager()->videoReceiver()->stop();
+            if(qgcApp()->toolbox()->videoManager()->videoReceiver()) {
+                if(_settingsManager->videoSettings()->disableWhenDisarmed()->rawValue().toBool()) {
+                    _settingsManager->videoSettings()->streamEnabled()->setRawValue(false);
+                    qgcApp()->toolbox()->videoManager()->videoReceiver()->stop();
+                }
             }
         }
     }
@@ -1654,8 +1656,8 @@ void Vehicle::_handlePing(LinkInterface* link, mavlink_message_t& message)
     mavlink_message_t   msg;
 
     mavlink_msg_ping_decode(&message, &ping);
-    mavlink_msg_ping_pack_chan(_mavlink->getSystemId(),
-                               _mavlink->getComponentId(),
+    mavlink_msg_ping_pack_chan(static_cast<uint8_t>(_mavlink->getSystemId()),
+                               static_cast<uint8_t>(_mavlink->getComponentId()),
                                priorityLink()->mavlinkChannel(),
                                &msg,
                                ping.time_usec,