diff --git a/src/VideoStreaming/VideoItem.cc b/src/VideoStreaming/VideoItem.cc
index 8a872c6..0a5679a 100644
--- a/src/VideoStreaming/VideoItem.cc
+++ b/src/VideoStreaming/VideoItem.cc
@@ -57,7 +57,7 @@ VideoSurface *VideoItem::surface() const
 #if defined(QGC_GST_STREAMING)
     return _data->surface.data();
 #else
-    return NULL;
+    return nullptr;
 #endif
 }
 
@@ -92,15 +92,15 @@ QSGGeometry* VideoItem::_createDefaultGeometry(QRectF& rectBound)
 QSGNode* VideoItem::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData*)
 {
     QRectF r = boundingRect();
-    QSGNode* newNode = 0;
+    QSGNode* newNode = nullptr;
 
     if (_data->surfaceDirty) {
         delete oldNode;
-        oldNode = 0;
+        oldNode = nullptr;
         _data->surfaceDirty = false;
     }
 
-    if (!_data->surface || _data->surface.data()->_data->videoSink == NULL) {
+    if (!_data->surface || _data->surface.data()->_data->videoSink == nullptr) {
         if (!oldNode) {
             QSGFlatColorMaterial *material = new QSGFlatColorMaterial;
             material->setColor(Qt::black);
diff --git a/src/VideoStreaming/VideoSurface.cc b/src/VideoStreaming/VideoSurface.cc
index 0ec705b..3bddbbb 100644
--- a/src/VideoStreaming/VideoSurface.cc
+++ b/src/VideoStreaming/VideoSurface.cc
@@ -35,7 +35,7 @@ VideoSurface::VideoSurface(QObject *parent)
 VideoSurface::~VideoSurface()
 {
 #if defined(QGC_GST_STREAMING)
-    if (!_refed && _data->videoSink != NULL) {
+    if (!_refed && _data->videoSink != nullptr) {
         gst_element_set_state(_data->videoSink, GST_STATE_NULL);
     }
     delete _data;
@@ -45,12 +45,12 @@ VideoSurface::~VideoSurface()
 #if defined(QGC_GST_STREAMING)
 GstElement* VideoSurface::videoSink()
 {
-    if (_data->videoSink == NULL) {
-        if ((_data->videoSink = gst_element_factory_make("qtquick2videosink", NULL)) == NULL) {
+    if (_data->videoSink == nullptr) {
+        if ((_data->videoSink = gst_element_factory_make("qtquick2videosink", nullptr)) == nullptr) {
             qCritical("Failed to create qtquick2videosink. Make sure it is installed correctly");
-            return NULL;
+            return nullptr;
         }
-        g_object_set(G_OBJECT(_data->videoSink), "sync", gboolean(false), NULL);
+        g_object_set(G_OBJECT(_data->videoSink), "sync", gboolean(false), nullptr);
         g_signal_connect(_data->videoSink, "update", G_CALLBACK(onUpdateThunk), (void* )this);
         _refed = true;
     }
@@ -59,7 +59,7 @@ GstElement* VideoSurface::videoSink()
 
 void VideoSurface::onUpdate()
 {
-    _lastFrame = time(0);
+    _lastFrame = time(nullptr);
     Q_FOREACH(QQuickItem *item, _data->items) {
         item->update();
     }
diff --git a/src/VideoStreaming/VideoSurface_p.h b/src/VideoStreaming/VideoSurface_p.h
index 0d40108..1bb1284 100644
--- a/src/VideoStreaming/VideoSurface_p.h
+++ b/src/VideoStreaming/VideoSurface_p.h
@@ -23,7 +23,7 @@ class VideoSurfacePrivate
 {
 public:
     VideoSurfacePrivate()
-        : videoSink(NULL)
+        : videoSink(nullptr)
     {
     }
     QSet<VideoItem*> items;
diff --git a/src/VideoStreaming/gstqtvideosink/delegates/basedelegate.cpp b/src/VideoStreaming/gstqtvideosink/delegates/basedelegate.cpp
index ee92753..65db69e 100644
--- a/src/VideoStreaming/gstqtvideosink/delegates/basedelegate.cpp
+++ b/src/VideoStreaming/gstqtvideosink/delegates/basedelegate.cpp
@@ -37,7 +37,7 @@ BaseDelegate::BaseDelegate(GstElement * sink, QObject * parent)
     , m_forceAspectRatio(false)
     , m_formatDirty(true)
     , m_isActive(false)
-    , m_buffer(NULL)
+    , m_buffer(nullptr)
     , m_sink(sink)
 {
 }
@@ -187,7 +187,7 @@ bool BaseDelegate::event(QEvent *event)
     {
         GST_LOG_OBJECT(m_sink, "Received deactivate event");
 
-        gst_buffer_replace (&m_buffer, NULL);
+        gst_buffer_replace (&m_buffer, nullptr);
         update();
 
         return true;
diff --git a/src/VideoStreaming/gstqtvideosink/delegates/qtvideosinkdelegate.cpp b/src/VideoStreaming/gstqtvideosink/delegates/qtvideosinkdelegate.cpp
index fd46d2a..1d1cbf1 100644
--- a/src/VideoStreaming/gstqtvideosink/delegates/qtvideosinkdelegate.cpp
+++ b/src/VideoStreaming/gstqtvideosink/delegates/qtvideosinkdelegate.cpp
@@ -225,7 +225,7 @@ void QtVideoSinkDelegate::changePainter(const BufferFormat & format)
     }
 
     GST_ELEMENT_ERROR(m_sink, RESOURCE, FAILED,
-            ("Failed to create a painter for the given format"), (NULL));
+            ("Failed to create a painter for the given format"), (nullptr));
 }
 
 void QtVideoSinkDelegate::destroyPainter()
diff --git a/src/VideoStreaming/gstqtvideosink/delegates/qwidgetvideosinkdelegate.cpp b/src/VideoStreaming/gstqtvideosink/delegates/qwidgetvideosinkdelegate.cpp
index 8f8318c..8188bf8 100644
--- a/src/VideoStreaming/gstqtvideosink/delegates/qwidgetvideosinkdelegate.cpp
+++ b/src/VideoStreaming/gstqtvideosink/delegates/qwidgetvideosinkdelegate.cpp
@@ -33,7 +33,7 @@ QWidgetVideoSinkDelegate::QWidgetVideoSinkDelegate(GstElement * sink, QObject *
 
 QWidgetVideoSinkDelegate::~QWidgetVideoSinkDelegate()
 {
-    setWidget(NULL);
+    setWidget(nullptr);
 }
 
 QWidget *QWidgetVideoSinkDelegate::widget() const
@@ -50,7 +50,7 @@ void QWidgetVideoSinkDelegate::setWidget(QWidget *widget)
         m_widget.data()->setAttribute(Qt::WA_OpaquePaintEvent, m_opaquePaintEventAttribute);
         m_widget.data()->update();
 
-        m_widget = NULL;
+        m_widget = nullptr;
     }
 
     if (widget) {
diff --git a/src/VideoStreaming/gstqtvideosink/gstqtglvideosink.cpp b/src/VideoStreaming/gstqtvideosink/gstqtglvideosink.cpp
index c92cca8..27c9ca7 100644
--- a/src/VideoStreaming/gstqtvideosink/gstqtglvideosink.cpp
+++ b/src/VideoStreaming/gstqtvideosink/gstqtglvideosink.cpp
@@ -97,7 +97,7 @@ void GstQtGLVideoSink::class_init(gpointer g_class, gpointer class_data)
         g_signal_new("paint", G_TYPE_FROM_CLASS(g_class),
                      static_cast<GSignalFlags>(G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION),
                      G_STRUCT_OFFSET(GstQtGLVideoSinkClass, paint),
-                     NULL, NULL,
+                     nullptr, nullptr,
                      qRealIsDouble() ?
                         g_cclosure_user_marshal_VOID__POINTER_DOUBLE_DOUBLE_DOUBLE_DOUBLE :
                         g_cclosure_user_marshal_VOID__POINTER_FLOAT_FLOAT_FLOAT_FLOAT,
@@ -114,7 +114,7 @@ void GstQtGLVideoSink::class_init(gpointer g_class, gpointer class_data)
     s_signals[UPDATE_SIGNAL] =
         g_signal_new("update", G_TYPE_FROM_CLASS(g_class),
                      G_SIGNAL_RUN_LAST,
-                     0, NULL, NULL,
+                     0, nullptr, nullptr,
                      g_cclosure_marshal_VOID__VOID,
                      G_TYPE_NONE, 0);
 
diff --git a/src/VideoStreaming/gstqtvideosink/gstqtglvideosinkbase.cpp b/src/VideoStreaming/gstqtvideosink/gstqtglvideosinkbase.cpp
index ee9605e..7b895cd 100644
--- a/src/VideoStreaming/gstqtvideosink/gstqtglvideosinkbase.cpp
+++ b/src/VideoStreaming/gstqtvideosink/gstqtglvideosinkbase.cpp
@@ -32,7 +32,7 @@ const char * const GstQtGLVideoSinkBase::s_colorbalance_labels[] = {
     "contrast", "brightness", "hue", "saturation"
 };
 
-GstQtVideoSinkBaseClass *GstQtGLVideoSinkBase::s_parent_class = 0;
+GstQtVideoSinkBaseClass *GstQtGLVideoSinkBase::s_parent_class = nullptr;
 
 //------------------------------
 
@@ -41,7 +41,7 @@ DEFINE_TYPE_WITH_CODE(GstQtGLVideoSinkBase, GST_TYPE_QT_VIDEO_SINK_BASE, init_in
 void GstQtGLVideoSinkBase::init_interfaces(GType type)
 {
     static const GInterfaceInfo colorbalance_info = {
-        (GInterfaceInitFunc) &GstQtGLVideoSinkBase::colorbalance_init, NULL, NULL
+        (GInterfaceInitFunc) &GstQtGLVideoSinkBase::colorbalance_init, nullptr, nullptr
     };
 
     g_type_add_interface_static(type, GST_TYPE_COLOR_BALANCE, &colorbalance_info);
@@ -52,7 +52,7 @@ void GstQtGLVideoSinkBase::init_interfaces(GType type)
 void GstQtGLVideoSinkBase::base_init(gpointer g_class)
 {
     GstElementClass *element_class = GST_ELEMENT_CLASS(g_class);
-    element_class->padtemplates = NULL; //get rid of the pad template of the base class
+    element_class->padtemplates = nullptr; //get rid of the pad template of the base class
 
     static GstStaticPadTemplate sink_pad_template =
         GST_STATIC_PAD_TEMPLATE("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
@@ -98,10 +98,10 @@ void GstQtGLVideoSinkBase::init(GTypeInstance *instance, gpointer g_class)
     GstQtGLVideoSinkBase *self = GST_QT_GL_VIDEO_SINK_BASE(instance);
 
     GstColorBalanceChannel *channel;
-    self->m_channels_list = NULL;
+    self->m_channels_list = nullptr;
 
     for (int i=0; i < LABEL_LAST; i++) {
-        channel = GST_COLOR_BALANCE_CHANNEL(g_object_new(GST_TYPE_COLOR_BALANCE_CHANNEL, NULL));
+        channel = GST_COLOR_BALANCE_CHANNEL(g_object_new(GST_TYPE_COLOR_BALANCE_CHANNEL, nullptr));
         channel->label = g_strdup(s_colorbalance_labels[i]);
         channel->min_value = -100;
         channel->max_value = 100;
diff --git a/src/VideoStreaming/gstqtvideosink/gstqtquick2videosink.cpp b/src/VideoStreaming/gstqtvideosink/gstqtquick2videosink.cpp
index fb07d1c..1375fd6 100644
--- a/src/VideoStreaming/gstqtvideosink/gstqtquick2videosink.cpp
+++ b/src/VideoStreaming/gstqtvideosink/gstqtquick2videosink.cpp
@@ -91,10 +91,10 @@ gst_qt_quick2_video_sink_init (GstQtQuick2VideoSink *self)
 
     // colorbalance
     GstColorBalanceChannel *channel;
-    self->priv->channels_list = NULL;
+    self->priv->channels_list = nullptr;
 
     for (int i=0; i < LABEL_LAST; i++) {
-        channel = GST_COLOR_BALANCE_CHANNEL(g_object_new(GST_TYPE_COLOR_BALANCE_CHANNEL, NULL));
+        channel = GST_COLOR_BALANCE_CHANNEL(g_object_new(GST_TYPE_COLOR_BALANCE_CHANNEL, nullptr));
         channel->label = g_strdup(s_colorbalance_labels[i]);
         channel->min_value = -100;
         channel->max_value = 100;
@@ -109,7 +109,7 @@ gst_qt_quick2_video_sink_finalize (GObject *gobject)
     GstQtQuick2VideoSink *self = GST_QT_QUICK2_VIDEO_SINK (gobject);
 
     delete self->priv->delegate;
-    self->priv->delegate = 0;
+    self->priv->delegate = nullptr;
 
     while (self->priv->channels_list) {
         GstColorBalanceChannel *channel =
@@ -422,7 +422,7 @@ gst_qt_quick2_video_sink_class_init (GstQtQuick2VideoSinkClass *klass)
         g_signal_new("update-node", G_TYPE_FROM_CLASS(klass),
             static_cast<GSignalFlags>(G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION),
             G_STRUCT_OFFSET(GstQtQuick2VideoSinkClass, update_node),
-            NULL, NULL,
+            nullptr, nullptr,
             qRealIsDouble() ?
               g_cclosure_user_marshal_POINTER__POINTER_DOUBLE_DOUBLE_DOUBLE_DOUBLE :
               g_cclosure_user_marshal_POINTER__POINTER_FLOAT_FLOAT_FLOAT_FLOAT,
@@ -438,7 +438,7 @@ gst_qt_quick2_video_sink_class_init (GstQtQuick2VideoSinkClass *klass)
     s_signals[SIGNAL_UPDATE] =
         g_signal_new("update", G_TYPE_FROM_CLASS(klass),
             G_SIGNAL_RUN_LAST,
-            0, NULL, NULL,
+            0, nullptr, nullptr,
             g_cclosure_marshal_VOID__VOID,
             G_TYPE_NONE, 0);
 
diff --git a/src/VideoStreaming/gstqtvideosink/gstqtvideosink.cpp b/src/VideoStreaming/gstqtvideosink/gstqtvideosink.cpp
index edb5a6d..0d242a4 100644
--- a/src/VideoStreaming/gstqtvideosink/gstqtvideosink.cpp
+++ b/src/VideoStreaming/gstqtvideosink/gstqtvideosink.cpp
@@ -77,7 +77,7 @@ void GstQtVideoSink::class_init(gpointer g_class, gpointer class_data)
         g_signal_new("paint", G_TYPE_FROM_CLASS(g_class),
                      static_cast<GSignalFlags>(G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION),
                      G_STRUCT_OFFSET(GstQtVideoSinkClass, paint),
-                     NULL, NULL,
+                     nullptr, nullptr,
                      qRealIsDouble() ?
                         g_cclosure_user_marshal_VOID__POINTER_DOUBLE_DOUBLE_DOUBLE_DOUBLE :
                         g_cclosure_user_marshal_VOID__POINTER_FLOAT_FLOAT_FLOAT_FLOAT,
@@ -94,7 +94,7 @@ void GstQtVideoSink::class_init(gpointer g_class, gpointer class_data)
     s_signals[UPDATE_SIGNAL] =
         g_signal_new("update", G_TYPE_FROM_CLASS(g_class),
                      G_SIGNAL_RUN_LAST,
-                     0, NULL, NULL,
+                     0, nullptr, nullptr,
                      g_cclosure_marshal_VOID__VOID,
                      G_TYPE_NONE, 0);
 }
diff --git a/src/VideoStreaming/gstqtvideosink/gstqtvideosinkbase.cpp b/src/VideoStreaming/gstqtvideosink/gstqtvideosinkbase.cpp
index 12dc844..a5286e9 100644
--- a/src/VideoStreaming/gstqtvideosink/gstqtvideosinkbase.cpp
+++ b/src/VideoStreaming/gstqtvideosink/gstqtvideosinkbase.cpp
@@ -33,7 +33,7 @@
 # define CAPS_FORMATS "{ BGRA, BGRx, RGB, RGB16 }"
 #endif
 
-GstVideoSinkClass *GstQtVideoSinkBase::s_parent_class = NULL;
+GstVideoSinkClass *GstQtVideoSinkBase::s_parent_class = nullptr;
 
 DEFINE_TYPE(GstQtVideoSinkBase, GST_TYPE_VIDEO_SINK)
 
diff --git a/src/VideoStreaming/gstqtvideosink/painters/videomaterial.cpp b/src/VideoStreaming/gstqtvideosink/painters/videomaterial.cpp
index 67daa4f..2a00b28 100644
--- a/src/VideoStreaming/gstqtvideosink/painters/videomaterial.cpp
+++ b/src/VideoStreaming/gstqtvideosink/painters/videomaterial.cpp
@@ -191,7 +191,7 @@ public:
 
 VideoMaterial *VideoMaterial::create(const BufferFormat & format)
 {
-    VideoMaterial *material = NULL;
+    VideoMaterial *material = nullptr;
 
     switch (format.videoFormat()) {
     // BGRx
@@ -264,7 +264,7 @@ VideoMaterial::~VideoMaterial()
             funcs->glDeleteTextures(m_textureCount, m_textureIds);
         }
     }
-    gst_buffer_replace(&m_frame, NULL);
+    gst_buffer_replace(&m_frame, nullptr);
 }
 
 int VideoMaterial::compare(const QSGMaterial *other) const
@@ -426,7 +426,7 @@ void VideoMaterial::bind()
     if (!funcs)
         return;
 
-    GstBuffer *frame = NULL;
+    GstBuffer *frame = nullptr;
 
     m_frameMutex.lock();
     if (m_frame)