Modernize code base

Run clang-tidy over the code base with some code modernization
options.

Change-Id: I9e74d1225bce333e74224e3b92c02c7e9884d8f5
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Doris Verria <doris.verria@qt.io>

40 files changed, 571 insertions, 636 deletions

diff --git a/tests/auto/integration/qaudiodeviceinfo/tst_qaudiodeviceinfo.cpp b/tests/auto/integration/qaudiodeviceinfo/tst_qaudiodeviceinfo.cpp
index 93f4c960a..3ebfdc7a0 100644
--- a/tests/auto/integration/qaudiodeviceinfo/tst_qaudiodeviceinfo.cpp
+++ b/tests/auto/integration/qaudiodeviceinfo/tst_qaudiodeviceinfo.cpp
@@ -40,7 +40,7 @@ class tst_QAudioDeviceInfo : public QObject
 {
     Q_OBJECT
 public:
-    tst_QAudioDeviceInfo(QObject* parent=0) : QObject(parent) {}
+    tst_QAudioDeviceInfo(QObject* parent=nullptr) : QObject(parent) {}
 
 private slots:
     void initTestCase();
diff --git a/tests/auto/integration/qaudioinput/tst_qaudioinput.cpp b/tests/auto/integration/qaudioinput/tst_qaudioinput.cpp
index bcc50f78a..9b8c47eaa 100644
--- a/tests/auto/integration/qaudioinput/tst_qaudioinput.cpp
+++ b/tests/auto/integration/qaudioinput/tst_qaudioinput.cpp
@@ -68,7 +68,7 @@ class tst_QAudioInput : public QObject
 {
     Q_OBJECT
 public:
-    tst_QAudioInput(QObject* parent=0) : QObject(parent) {}
+    tst_QAudioInput(QObject* parent=nullptr) : QObject(parent) {}
 
 private slots:
     void initTestCase();
@@ -104,7 +104,7 @@ private slots:
     void volume();
 
 private:
-    typedef QSharedPointer<QFile> FilePtr;
+    using FilePtr = QSharedPointer<QFile>;
 
     QString formatToFileName(const QAudioFormat &format);
 
diff --git a/tests/auto/integration/qaudiooutput/tst_qaudiooutput.cpp b/tests/auto/integration/qaudiooutput/tst_qaudiooutput.cpp
index a81706ec1..8bf6daff2 100644
--- a/tests/auto/integration/qaudiooutput/tst_qaudiooutput.cpp
+++ b/tests/auto/integration/qaudiooutput/tst_qaudiooutput.cpp
@@ -62,7 +62,7 @@ class tst_QAudioOutput : public QObject
 {
     Q_OBJECT
 public:
-    tst_QAudioOutput(QObject* parent=0) : QObject(parent) {}
+    tst_QAudioOutput(QObject* parent=nullptr) : QObject(parent) {}
 
 private slots:
     void initTestCase();
@@ -102,7 +102,7 @@ private slots:
     void volume();
 
 private:
-    typedef QSharedPointer<QFile> FilePtr;
+    using FilePtr = QSharedPointer<QFile>;
 
     QString formatToFileName(const QAudioFormat &format);
     void createSineWaveData(const QAudioFormat &format, qint64 length, int sampleRate = 440);
diff --git a/tests/auto/integration/qdeclarativevideooutput/tst_qdeclarativevideooutput.cpp b/tests/auto/integration/qdeclarativevideooutput/tst_qdeclarativevideooutput.cpp
index b31947738..cd5f2cda9 100644
--- a/tests/auto/integration/qdeclarativevideooutput/tst_qdeclarativevideooutput.cpp
+++ b/tests/auto/integration/qdeclarativevideooutput/tst_qdeclarativevideooutput.cpp
@@ -49,11 +49,11 @@ class SurfaceHolder : public QObject
 public:
     SurfaceHolder(QObject *parent)
         : QObject(parent)
-        , m_surface(0)
+        , m_surface(nullptr)
     {
     }
 
-    QAbstractVideoSurface *videoSurface() const
+    [[nodiscard]] QAbstractVideoSurface *videoSurface() const
     {
         return m_surface;
     }
@@ -95,7 +95,7 @@ class tst_QDeclarativeVideoOutput : public QObject
 public:
     tst_QDeclarativeVideoOutput();
 
-    ~tst_QDeclarativeVideoOutput()
+    ~tst_QDeclarativeVideoOutput() override
     {
         delete m_mappingOutput;
         delete m_mappingSurface;
@@ -128,9 +128,9 @@ private:
     QQmlEngine m_engine;
 
     // Variables used for the mapping test
-    QQmlComponent *m_mappingComponent;
-    QObject *m_mappingOutput;
-    SurfaceHolder *m_mappingSurface;
+    QQmlComponent *m_mappingComponent = nullptr;
+    QObject *m_mappingOutput = nullptr;
+    SurfaceHolder *m_mappingSurface = nullptr;
 
     void updateOutputGeometry(QObject *output);
 
@@ -146,7 +146,7 @@ void tst_QDeclarativeVideoOutput::initTestCase()
     m_mappingSurface = new SurfaceHolder(this);
 
     m_mappingOutput = m_mappingComponent->create();
-    QVERIFY(m_mappingOutput != 0);
+    QVERIFY(m_mappingOutput != nullptr);
 
     m_mappingOutput->setProperty("source", QVariant::fromValue(static_cast<QObject*>(m_mappingSurface)));
 
@@ -158,9 +158,6 @@ Q_DECLARE_METATYPE(QDeclarativeVideoOutput::FillMode)
 Q_DECLARE_METATYPE(QDeclarativeVideoOutput::FlushMode)
 
 tst_QDeclarativeVideoOutput::tst_QDeclarativeVideoOutput()
-    : m_mappingComponent(0)
-    , m_mappingOutput(0)
-    , m_mappingSurface(0)
 {
     qRegisterMetaType<QDeclarativeVideoOutput::FillMode>();
 }
@@ -171,7 +168,7 @@ void tst_QDeclarativeVideoOutput::fillMode()
     component.loadUrl(QUrl("qrc:/main.qml"));
 
     QObject *videoOutput = component.create();
-    QVERIFY(videoOutput != 0);
+    QVERIFY(videoOutput != nullptr);
 
     QSignalSpy propSpy(videoOutput, SIGNAL(fillModeChanged(QDeclarativeVideoOutput::FillMode)));
 
@@ -200,7 +197,7 @@ void tst_QDeclarativeVideoOutput::flushMode()
     component.loadUrl(QUrl("qrc:/main.qml"));
 
     QObject *videoOutput = component.create();
-    QVERIFY(videoOutput != 0);
+    QVERIFY(videoOutput != nullptr);
 
     QSignalSpy propSpy(videoOutput, SIGNAL(flushModeChanged()));
 
@@ -218,7 +215,7 @@ void tst_QDeclarativeVideoOutput::orientation()
     component.loadUrl(QUrl("qrc:/main.qml"));
 
     QObject *videoOutput = component.create();
-    QVERIFY(videoOutput != 0);
+    QVERIFY(videoOutput != nullptr);
 
     QSignalSpy propSpy(videoOutput, SIGNAL(orientationChanged()));
 
@@ -271,15 +268,15 @@ void tst_QDeclarativeVideoOutput::surfaceSource()
     component.loadUrl(QUrl("qrc:/main.qml"));
 
     QObject *videoOutput = component.create();
-    QVERIFY(videoOutput != 0);
+    QVERIFY(videoOutput != nullptr);
 
     SurfaceHolder holder(this);
 
-    QCOMPARE(holder.videoSurface(), static_cast<QAbstractVideoSurface*>(0));
+    QCOMPARE(holder.videoSurface(), static_cast<QAbstractVideoSurface*>(nullptr));
 
     videoOutput->setProperty("source", QVariant::fromValue(static_cast<QObject*>(&holder)));
 
-    QVERIFY(holder.videoSurface() != 0);
+    QVERIFY(holder.videoSurface() != nullptr);
 
     // Now we could do things with the surface..
     const QList<QVideoFrame::PixelFormat> formats = holder.videoSurface()->supportedPixelFormats();
@@ -302,7 +299,7 @@ void tst_QDeclarativeVideoOutput::surfaceSource()
     delete videoOutput;
 
     // This should clear the surface
-    QCOMPARE(holder.videoSurface(), static_cast<QAbstractVideoSurface*>(0));
+    QCOMPARE(holder.videoSurface(), static_cast<QAbstractVideoSurface*>(nullptr));
 
     // Also, creating two sources, setting them in order, and destroying the first
     // should not zero holder.videoSurface()
@@ -329,8 +326,8 @@ void tst_QDeclarativeVideoOutput::surfaceSource()
     SurfaceHolder holder2(this);
     videoOutput2->setProperty("source", QVariant::fromValue(static_cast<QObject*>(&holder2)));
 
-    QCOMPARE(holder.videoSurface(), static_cast<QAbstractVideoSurface*>(0));
-    QVERIFY(holder2.videoSurface() != 0);
+    QCOMPARE(holder.videoSurface(), static_cast<QAbstractVideoSurface*>(nullptr));
+    QVERIFY(holder2.videoSurface() != nullptr);
 
     // Finally a combination - set the same source to two things, then assign a new source
     // to the first output - should not reset the first source
@@ -338,11 +335,11 @@ void tst_QDeclarativeVideoOutput::surfaceSource()
     videoOutput->setProperty("source", QVariant::fromValue(static_cast<QObject*>(&holder2)));
 
     // Both vo and vo2 were pointed to holder2 - setting vo2 should not clear holder2
-    QVERIFY(holder2.videoSurface() != 0);
-    QVERIFY(holder.videoSurface() == 0);
+    QVERIFY(holder2.videoSurface() != nullptr);
+    QVERIFY(holder.videoSurface() == nullptr);
     videoOutput2->setProperty("source", QVariant::fromValue(static_cast<QObject*>(&holder)));
-    QVERIFY(holder2.videoSurface() != 0);
-    QVERIFY(holder.videoSurface() != 0);
+    QVERIFY(holder2.videoSurface() != nullptr);
+    QVERIFY(holder.videoSurface() != nullptr);
 
     // They should also be independent
     QVERIFY(holder.videoSurface() != holder2.videoSurface());
@@ -386,7 +383,7 @@ void tst_QDeclarativeVideoOutput::sourceRect()
     component.loadUrl(QUrl("qrc:/main.qml"));
 
     QObject *videoOutput = component.create();
-    QVERIFY(videoOutput != 0);
+    QVERIFY(videoOutput != nullptr);
 
     SurfaceHolder holder(this);
 
diff --git a/tests/auto/integration/qdeclarativevideooutput_window/tst_qdeclarativevideooutput_window.cpp b/tests/auto/integration/qdeclarativevideooutput_window/tst_qdeclarativevideooutput_window.cpp
index 645b5d3c6..a4b012a9c 100644
--- a/tests/auto/integration/qdeclarativevideooutput_window/tst_qdeclarativevideooutput_window.cpp
+++ b/tests/auto/integration/qdeclarativevideooutput_window/tst_qdeclarativevideooutput_window.cpp
@@ -47,11 +47,11 @@ class SourceObject : public QObject
     Q_OBJECT
     Q_PROPERTY(QObject *mediaObject READ mediaObject CONSTANT)
 public:
-    explicit SourceObject(QMediaObject *mediaObject, QObject *parent = 0)
+    explicit SourceObject(QMediaObject *mediaObject, QObject *parent = nullptr)
         : QObject(parent), m_mediaObject(mediaObject)
     {}
 
-    QObject *mediaObject() const
+    [[nodiscard]] QObject *mediaObject() const
     { return m_mediaObject; }
 
 private:
@@ -61,60 +61,48 @@ private:
 class QtTestWindowControl : public QVideoWindowControl
 {
 public:
-    QtTestWindowControl()
-        : m_winId(0)
-        , m_repaintCount(0)
-        , m_brightness(0)
-        , m_contrast(0)
-        , m_hue(0)
-        , m_saturation(0)
-        , m_aspectRatioMode(Qt::KeepAspectRatio)
-        , m_fullScreen(0)
-    {
-    }
-
-    WId winId() const { return m_winId; }
-    void setWinId(WId id) { m_winId = id; }
+    [[nodiscard]] WId winId() const override { return m_winId; }
+    void setWinId(WId id) override { m_winId = id; }
 
-    QRect displayRect() const { return m_displayRect; }
-    void setDisplayRect(const QRect &rect) { m_displayRect = rect; }
+    [[nodiscard]] QRect displayRect() const override { return m_displayRect; }
+    void setDisplayRect(const QRect &rect) override { m_displayRect = rect; }
 
-    bool isFullScreen() const { return m_fullScreen; }
-    void setFullScreen(bool fullScreen) { emit fullScreenChanged(m_fullScreen = fullScreen); }
+    [[nodiscard]] bool isFullScreen() const override { return m_fullScreen; }
+    void setFullScreen(bool fullScreen) override { emit fullScreenChanged(m_fullScreen = fullScreen); }
 
-    int repaintCount() const { return m_repaintCount; }
+    [[nodiscard]] int repaintCount() const { return m_repaintCount; }
     void setRepaintCount(int count) { m_repaintCount = count; }
-    void repaint() { ++m_repaintCount; }
+    void repaint() override { ++m_repaintCount; }
 
-    QSize nativeSize() const { return m_nativeSize; }
+    [[nodiscard]] QSize nativeSize() const override { return m_nativeSize; }
     void setNativeSize(const QSize &size) { m_nativeSize = size; emit nativeSizeChanged(); }
 
-    Qt::AspectRatioMode aspectRatioMode() const { return m_aspectRatioMode; }
-    void setAspectRatioMode(Qt::AspectRatioMode mode) { m_aspectRatioMode = mode; }
+    [[nodiscard]] Qt::AspectRatioMode aspectRatioMode() const override { return m_aspectRatioMode; }
+    void setAspectRatioMode(Qt::AspectRatioMode mode) override { m_aspectRatioMode = mode; }
 
-    int brightness() const { return m_brightness; }
-    void setBrightness(int brightness) { emit brightnessChanged(m_brightness = brightness); }
+    [[nodiscard]] int brightness() const override { return m_brightness; }
+    void setBrightness(int brightness) override { emit brightnessChanged(m_brightness = brightness); }
 
-    int contrast() const { return m_contrast; }
-    void setContrast(int contrast) { emit contrastChanged(m_contrast = contrast); }
+    [[nodiscard]] int contrast() const override { return m_contrast; }
+    void setContrast(int contrast) override { emit contrastChanged(m_contrast = contrast); }
 
-    int hue() const { return m_hue; }
-    void setHue(int hue) { emit hueChanged(m_hue = hue); }
+    [[nodiscard]] int hue() const override { return m_hue; }
+    void setHue(int hue) override { emit hueChanged(m_hue = hue); }
 
-    int saturation() const { return m_saturation; }
-    void setSaturation(int saturation) { emit saturationChanged(m_saturation = saturation); }
+    [[nodiscard]] int saturation() const override { return m_saturation; }
+    void setSaturation(int saturation) override { emit saturationChanged(m_saturation = saturation); }
 
 private:
-    WId m_winId;
-    int m_repaintCount;
-    int m_brightness;
-    int m_contrast;
-    int m_hue;
-    int m_saturation;
-    Qt::AspectRatioMode m_aspectRatioMode;
+    WId m_winId = 0;
+    int m_repaintCount = 0;
+    int m_brightness = 0;
+    int m_contrast = 0;
+    int m_hue = 0;
+    int m_saturation = 0;
+    Qt::AspectRatioMode m_aspectRatioMode = Qt::KeepAspectRatio;
     QRect m_displayRect;
     QSize m_nativeSize;
-    bool m_fullScreen;
+    bool m_fullScreen = 0;
 };
 
 class QtTestVideoService : public QMediaService
@@ -122,18 +110,18 @@ class QtTestVideoService : public QMediaService
     Q_OBJECT
 public:
     QtTestVideoService(QtTestWindowControl *window)
-        : QMediaService(0)
+        : QMediaService(nullptr)
         , windowControl(window)
     {}
 
-    QMediaControl *requestControl(const char *name)
+    QMediaControl *requestControl(const char *name) override
     {
         if (qstrcmp(name, QVideoWindowControl_iid) == 0)
             return windowControl;
-        return 0;
+        return nullptr;
     }
 
-    void releaseControl(QMediaControl *control)
+    void releaseControl(QMediaControl *control) override
     {
         Q_ASSERT(control);
     }
@@ -146,7 +134,7 @@ class QtTestVideoObject : public QMediaObject
     Q_OBJECT
 public:
     explicit QtTestVideoObject(QtTestVideoService *service):
-        QMediaObject(0, service)
+        QMediaObject(nullptr, service)
     {
     }
 };
@@ -156,14 +144,14 @@ class tst_QDeclarativeVideoOutputWindow : public QObject
     Q_OBJECT
 public:
     tst_QDeclarativeVideoOutputWindow()
-        : QObject(0)
+        : QObject(nullptr)
         , m_service(new QtTestVideoService(&m_windowControl))
         , m_videoObject(m_service)
         , m_sourceObject(&m_videoObject)
     {
     }
 
-    ~tst_QDeclarativeVideoOutputWindow()
+    ~tst_QDeclarativeVideoOutputWindow() override
     {
     }
 
@@ -212,7 +200,7 @@ void tst_QDeclarativeVideoOutputWindow::cleanupTestCase()
     // Make sure that QDeclarativeVideoOutput doesn't segfault when it is being destroyed after
     // the service is already gone
     delete m_service;
-    m_service = 0;
+    m_service = nullptr;
     m_view.setSource(QUrl());
     m_rootItem.reset();
 }
@@ -261,7 +249,7 @@ void tst_QDeclarativeVideoOutputWindow::geometryChange()
 
 void tst_QDeclarativeVideoOutputWindow::resetCanvas()
 {
-    m_rootItem->setParentItem(0);
+    m_rootItem->setParentItem(nullptr);
     QCOMPARE((int)m_windowControl.winId(), 0);
 }
 
diff --git a/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp b/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
index d12a5d0cf..9323c5836 100644
--- a/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
+++ b/tests/auto/integration/qmediaplayerbackend/tst_qmediaplayerbackend.cpp
@@ -110,15 +110,15 @@ public:
     void setSupportedFormats(const QList<QVideoFrame::PixelFormat>& formats) { m_supported = formats; }
 
     //video surface
-    QList<QVideoFrame::PixelFormat> supportedPixelFormats(
-            QAbstractVideoBuffer::HandleType handleType = QAbstractVideoBuffer::NoHandle) const;
+    [[nodiscard]] QList<QVideoFrame::PixelFormat> supportedPixelFormats(
+            QAbstractVideoBuffer::HandleType handleType = QAbstractVideoBuffer::NoHandle) const override;
 
-    bool start(const QVideoSurfaceFormat &format);
-    void stop();
-    bool present(const QVideoFrame &frame);
+    bool start(const QVideoSurfaceFormat &format) override;
+    void stop() override;
+    bool present(const QVideoFrame &frame) override;
 
     QList<QVideoFrame> m_frameList;
-    int m_totalFrames; // used instead of the list when frames are not stored
+    int m_totalFrames = 0; // used instead of the list when frames are not stored
 
 private:
     bool m_storeFrames;
@@ -130,11 +130,9 @@ class ProbeDataHandler : public QObject
     Q_OBJECT
 
 public:
-    ProbeDataHandler() : isVideoFlushCalled(false) { }
-
     QList<QVideoFrame> m_frameList;
     QList<QAudioBuffer> m_bufferList;
-    bool isVideoFlushCalled;
+    bool isVideoFlushCalled = false;
 
 public slots:
     void processFrame(const QVideoFrame&);
@@ -601,7 +599,7 @@ private slots:
     {
         if (status == QMediaPlayer::EndOfMedia) {
             player-> deleteLater();
-            player = 0;
+            player = nullptr;
         }
     }
 
@@ -1486,9 +1484,8 @@ void tst_QMediaPlayerBackend::playFromBuffer()
     QVERIFY2(surface.m_totalFrames >= 25, qPrintable(QString("Expected >= 25, got %1").arg(surface.m_totalFrames)));
 }
 
-TestVideoSurface::TestVideoSurface(bool storeFrames):
-    m_totalFrames(0),
-    m_storeFrames(storeFrames)
+TestVideoSurface::TestVideoSurface(bool storeFrames)
+    : m_storeFrames(storeFrames)
 {
     // set default formats
     m_supported << QVideoFrame::Format_RGB32
diff --git a/tests/auto/integration/qsoundeffect/tst_qsoundeffect.cpp b/tests/auto/integration/qsoundeffect/tst_qsoundeffect.cpp
index 7cbd57007..f686da07b 100644
--- a/tests/auto/integration/qsoundeffect/tst_qsoundeffect.cpp
+++ b/tests/auto/integration/qsoundeffect/tst_qsoundeffect.cpp
@@ -39,7 +39,7 @@ class tst_QSoundEffect : public QObject
 {
     Q_OBJECT
 public:
-    tst_QSoundEffect(QObject* parent=0) : QObject(parent) {}
+    tst_QSoundEffect(QObject* parent=nullptr) : QObject(parent) {}
 
 public slots:
     void init();
diff --git a/tests/auto/unit/qabstractvideobuffer/tst_qabstractvideobuffer.cpp b/tests/auto/unit/qabstractvideobuffer/tst_qabstractvideobuffer.cpp
index 98dfd97b2..146b26d30 100644
--- a/tests/auto/unit/qabstractvideobuffer/tst_qabstractvideobuffer.cpp
+++ b/tests/auto/unit/qabstractvideobuffer/tst_qabstractvideobuffer.cpp
@@ -43,7 +43,7 @@ class tst_QAbstractVideoBuffer : public QObject
     Q_OBJECT
 public:
     tst_QAbstractVideoBuffer();
-    ~tst_QAbstractVideoBuffer();
+    ~tst_QAbstractVideoBuffer() override;
 
 public slots:
     void initTestCase();
@@ -65,10 +65,10 @@ class QtTestVideoBuffer : public QAbstractVideoBuffer
 public:
     QtTestVideoBuffer(QAbstractVideoBuffer::HandleType type) : QAbstractVideoBuffer(type) {}
 
-    MapMode mapMode() const { return QAbstractVideoBuffer::ReadWrite; }
+    [[nodiscard]] MapMode mapMode() const override { return QAbstractVideoBuffer::ReadWrite; }
 
-    uchar *map(MapMode, int *, int *) { return 0; }
-    void unmap() {}
+    uchar *map(MapMode, int *, int *) override { return nullptr; }
+    void unmap() override {}
 };
 
 tst_QAbstractVideoBuffer::tst_QAbstractVideoBuffer()
diff --git a/tests/auto/unit/qabstractvideosurface/tst_qabstractvideosurface.cpp b/tests/auto/unit/qabstractvideosurface/tst_qabstractvideosurface.cpp
index b18dba5f7..3768eb0f4 100644
--- a/tests/auto/unit/qabstractvideosurface/tst_qabstractvideosurface.cpp
+++ b/tests/auto/unit/qabstractvideosurface/tst_qabstractvideosurface.cpp
@@ -38,7 +38,7 @@ class tst_QAbstractVideoSurface : public QObject
     Q_OBJECT
 public:
     tst_QAbstractVideoSurface();
-    ~tst_QAbstractVideoSurface();
+    ~tst_QAbstractVideoSurface() override;
 
 public slots:
     void initTestCase();
@@ -66,17 +66,17 @@ class QtTestVideoSurface : public QAbstractVideoSurface
 {
     Q_OBJECT
 public:
-    explicit QtTestVideoSurface(QObject *parent = 0) : QAbstractVideoSurface(parent) {}
-    explicit QtTestVideoSurface(SupportedFormatMap formats, QObject *parent = 0)
+    explicit QtTestVideoSurface(QObject *parent = nullptr) : QAbstractVideoSurface(parent) {}
+    explicit QtTestVideoSurface(SupportedFormatMap formats, QObject *parent = nullptr)
             : QAbstractVideoSurface(parent), supportedFormats(formats) {}
 
-    QList<QVideoFrame::PixelFormat> supportedPixelFormats(
-            QAbstractVideoBuffer::HandleType handleType = QAbstractVideoBuffer::NoHandle) const
+    [[nodiscard]] QList<QVideoFrame::PixelFormat> supportedPixelFormats(
+            QAbstractVideoBuffer::HandleType handleType = QAbstractVideoBuffer::NoHandle) const override
     {
         return supportedFormats.values(handleType);
     }
 
-    bool present(const QVideoFrame &) { return false; }
+    bool present(const QVideoFrame &) override { return false; }
 
     using QAbstractVideoSurface::setError;
 
diff --git a/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp b/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp
index 1b01ca501..72a8642d4 100644
--- a/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp
+++ b/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp
@@ -37,7 +37,7 @@ class tst_QAudioBuffer : public QObject
 
 public:
     tst_QAudioBuffer();
-    ~tst_QAudioBuffer();
+    ~tst_QAudioBuffer() override;
 
 private Q_SLOTS:
     void ctors();
@@ -83,9 +83,9 @@ void tst_QAudioBuffer::ctors()
 {
     // Null buffer
     QVERIFY(!mNull->isValid());
-    QVERIFY(mNull->constData() == 0);
-    QVERIFY(mNull->data() == 0);
-    QVERIFY(((const QAudioBuffer*)mNull)->data() == 0);
+    QVERIFY(mNull->constData() == nullptr);
+    QVERIFY(mNull->data() == nullptr);
+    QVERIFY(((const QAudioBuffer*)mNull)->data() == nullptr);
     QCOMPARE(mNull->duration(), 0LL);
     QCOMPARE(mNull->byteCount(), 0);
     QCOMPARE(mNull->sampleCount(), 0);
@@ -94,9 +94,9 @@ void tst_QAudioBuffer::ctors()
 
     // Empty buffer
     QVERIFY(mEmpty->isValid());
-    QVERIFY(mEmpty->constData() != 0);
-    QVERIFY(mEmpty->data() != 0);
-    QVERIFY(((const QAudioBuffer*)mEmpty)->data() != 0);
+    QVERIFY(mEmpty->constData() != nullptr);
+    QVERIFY(mEmpty->data() != nullptr);
+    QVERIFY(((const QAudioBuffer*)mEmpty)->data() != nullptr);
     QCOMPARE(mEmpty->sampleCount(), 1000);
     QCOMPARE(mEmpty->frameCount(), 500);
     QCOMPARE(mEmpty->duration(), 50000LL);
@@ -105,9 +105,9 @@ void tst_QAudioBuffer::ctors()
 
     // bytearray buffer
     QVERIFY(mFromArray->isValid());
-    QVERIFY(mFromArray->constData() != 0);
-    QVERIFY(mFromArray->data() != 0);
-    QVERIFY(((const QAudioBuffer*)mFromArray)->data() != 0);
+    QVERIFY(mFromArray->constData() != nullptr);
+    QVERIFY(mFromArray->data() != nullptr);
+    QVERIFY(((const QAudioBuffer*)mFromArray)->data() != nullptr);
     /// 4000 bytes at 10KHz, 2ch, 16bit = 40kBps -> 0.1s
     QCOMPARE(mFromArray->duration(), 100000LL);
     QCOMPARE(mFromArray->byteCount(), 4000);
@@ -119,9 +119,9 @@ void tst_QAudioBuffer::ctors()
     // Now some invalid buffers
     QAudioBuffer badFormat(1000, QAudioFormat());
     QVERIFY(!badFormat.isValid());
-    QVERIFY(badFormat.constData() == 0);
-    QVERIFY(badFormat.data() == 0);
-    QVERIFY(((const QAudioBuffer*)&badFormat)->data() == 0);
+    QVERIFY(badFormat.constData() == nullptr);
+    QVERIFY(badFormat.data() == nullptr);
+    QVERIFY(((const QAudioBuffer*)&badFormat)->data() == nullptr);
     QCOMPARE(badFormat.duration(), 0LL);
     QCOMPARE(badFormat.byteCount(), 0);
     QCOMPARE(badFormat.sampleCount(), 0);
@@ -130,9 +130,9 @@ void tst_QAudioBuffer::ctors()
 
     QAudioBuffer badArray(QByteArray(), mFormat);
     QVERIFY(!badArray.isValid());
-    QVERIFY(badArray.constData() == 0);
-    QVERIFY(badArray.data() == 0);
-    QVERIFY(((const QAudioBuffer*)&badArray)->data() == 0);
+    QVERIFY(badArray.constData() == nullptr);
+    QVERIFY(badArray.data() == nullptr);
+    QVERIFY(((const QAudioBuffer*)&badArray)->data() == nullptr);
     QCOMPARE(badArray.duration(), 0LL);
     QCOMPARE(badArray.byteCount(), 0);
     QCOMPARE(badArray.sampleCount(), 0);
@@ -141,9 +141,9 @@ void tst_QAudioBuffer::ctors()
 
     QAudioBuffer badBoth = QAudioBuffer(QByteArray(), QAudioFormat());
     QVERIFY(!badBoth.isValid());
-    QVERIFY(badBoth.constData() == 0);
-    QVERIFY(badBoth.data() == 0);
-    QVERIFY(((const QAudioBuffer*)&badBoth)->data() == 0);
+    QVERIFY(badBoth.constData() == nullptr);
+    QVERIFY(badBoth.data() == nullptr);
+    QVERIFY(((const QAudioBuffer*)&badBoth)->data() == nullptr);
     QCOMPARE(badBoth.duration(), 0LL);
     QCOMPARE(badBoth.byteCount(), 0);
     QCOMPARE(badBoth.sampleCount(), 0);
@@ -159,7 +159,7 @@ void tst_QAudioBuffer::assign()
 void tst_QAudioBuffer::constData() const
 {
     const void *data = mEmpty->constData();
-    QVERIFY(data != 0);
+    QVERIFY(data != nullptr);
 
     const unsigned int *idata = reinterpret_cast<const unsigned int*>(data);
     QCOMPARE(*idata, 0U);
@@ -171,7 +171,7 @@ void tst_QAudioBuffer::constData() const
 
     // The bytearray one should be 0x80
     data = mFromArray->constData();
-    QVERIFY(data != 0);
+    QVERIFY(data != nullptr);
 
     idata = reinterpret_cast<const unsigned int *>(data);
     QEXPECT_FAIL("", "Unsigned 16bits are cleared to 0x8080 currently", Continue);
@@ -185,7 +185,7 @@ void tst_QAudioBuffer::constData() const
 void tst_QAudioBuffer::data_const() const
 {
     const void *data = ((const QAudioBuffer*)mEmpty)->data();
-    QVERIFY(data != 0);
+    QVERIFY(data != nullptr);
 
     const unsigned int *idata = reinterpret_cast<const unsigned int*>(data);
     QCOMPARE(*idata, 0U);
@@ -197,7 +197,7 @@ void tst_QAudioBuffer::data_const() const
 
     // The bytearray one should be 0x80
     data = ((const QAudioBuffer*)mFromArray)->data();
-    QVERIFY(data != 0);
+    QVERIFY(data != nullptr);
 
     idata = reinterpret_cast<const unsigned int *>(data);
     QEXPECT_FAIL("", "Unsigned 16bits are cleared to 0x8080 currently", Continue);
@@ -211,7 +211,7 @@ void tst_QAudioBuffer::data_const() const
 void tst_QAudioBuffer::data()
 {
     void *data = mEmpty->data();
-    QVERIFY(data != 0);
+    QVERIFY(data != nullptr);
 
     unsigned int *idata = reinterpret_cast<unsigned int*>(data);
     QCOMPARE(*idata, 0U);
@@ -223,7 +223,7 @@ void tst_QAudioBuffer::data()
 
     // The bytearray one should be 0x80
     data = mFromArray->data();
-    QVERIFY(data != 0);
+    QVERIFY(data != nullptr);
 
     idata = reinterpret_cast<unsigned int *>(data);
     QEXPECT_FAIL("", "Unsigned 16bits are cleared to 0x8080 currently", Continue);
diff --git a/tests/auto/unit/qaudiodecoder/tst_qaudiodecoder.cpp b/tests/auto/unit/qaudiodecoder/tst_qaudiodecoder.cpp
index cfcbc5f3f..2ab712e21 100644
--- a/tests/auto/unit/qaudiodecoder/tst_qaudiodecoder.cpp
+++ b/tests/auto/unit/qaudiodecoder/tst_qaudiodecoder.cpp
@@ -258,7 +258,7 @@ void tst_QAudioDecoder::source()
     QAudioDecoder d;
 
     QVERIFY(d.sourceFilename().isEmpty());
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 
     QFile f;
     d.setSourceDevice(&f);
@@ -267,19 +267,19 @@ void tst_QAudioDecoder::source()
 
     d.setSourceFilename("Foo");
     QVERIFY(d.sourceFilename() == QString("Foo"));
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 
-    d.setSourceDevice(0);
+    d.setSourceDevice(nullptr);
     QVERIFY(d.sourceFilename().isEmpty());
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 
     d.setSourceFilename("Foo");
     QVERIFY(d.sourceFilename() == QString("Foo"));
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 
     d.setSourceFilename(QString());
     QVERIFY(d.sourceFilename() == QString());
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 }
 
 void tst_QAudioDecoder::readAll()
@@ -344,9 +344,9 @@ void tst_QAudioDecoder::nullControl()
     QVERIFY(d.sourceFilename().isEmpty());
 
     QFile f;
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
     d.setSourceDevice(&f);
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 
     QAudioFormat format;
     format.setChannelCount(2);
@@ -370,7 +370,7 @@ void tst_QAudioDecoder::nullControl()
 
 void tst_QAudioDecoder::nullService()
 {
-    mockProvider->service = 0;
+    mockProvider->service = nullptr;
     QAudioDecoder d;
 
     QVERIFY(d.error() == QAudioDecoder::ServiceMissingError);
@@ -385,9 +385,9 @@ void tst_QAudioDecoder::nullService()
     QVERIFY(d.sourceFilename().isEmpty());
 
     QFile f;
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
     d.setSourceDevice(&f);
-    QVERIFY(d.sourceDevice() == 0);
+    QVERIFY(d.sourceDevice() == nullptr);
 
     QAudioFormat format;
     format.setChannelCount(2);
diff --git a/tests/auto/unit/qaudioformat/tst_qaudioformat.cpp b/tests/auto/unit/qaudioformat/tst_qaudioformat.cpp
index 91b60090e..736b843c2 100644
--- a/tests/auto/unit/qaudioformat/tst_qaudioformat.cpp
+++ b/tests/auto/unit/qaudioformat/tst_qaudioformat.cpp
@@ -41,7 +41,7 @@ class tst_QAudioFormat : public QObject
     Q_OBJECT
 
 public:
-    tst_QAudioFormat(QObject* parent=0) : QObject(parent) {}
+    tst_QAudioFormat(QObject* parent=nullptr) : QObject(parent) {}
 
 private slots:
     void checkNull();
diff --git a/tests/auto/unit/qaudioprobe/tst_qaudioprobe.cpp b/tests/auto/unit/qaudioprobe/tst_qaudioprobe.cpp
index 3bab32129..67112615f 100644
--- a/tests/auto/unit/qaudioprobe/tst_qaudioprobe.cpp
+++ b/tests/auto/unit/qaudioprobe/tst_qaudioprobe.cpp
@@ -69,7 +69,7 @@ void tst_QAudioProbe::init()
     mockMediaRecorderService = new MockMediaRecorderService(this, mockMediaRecorderControl);
     mockProvider = new MockMediaServiceProvider(mockMediaRecorderService);
     mockProvider->deleteServiceOnRelease = true;
-    recorder = 0;
+    recorder = nullptr;
 
     QMediaServiceProvider::setDefaultServiceProvider(mockProvider);
 }
@@ -79,15 +79,15 @@ void tst_QAudioProbe::cleanup()
     delete recorder;
     delete mockProvider;
     delete mockMediaRecorderControl;
-    mockMediaRecorderControl = 0;
-    mockMediaRecorderService = 0;
-    mockProvider = 0;
-    recorder = 0;
+    mockMediaRecorderControl = nullptr;
+    mockMediaRecorderService = nullptr;
+    mockProvider = nullptr;
+    recorder = nullptr;
 }
 
 void tst_QAudioProbe::testNullService()
 {
-    mockProvider->service = 0;
+    mockProvider->service = nullptr;
     recorder = new QAudioRecorder;
 
     QVERIFY(!recorder->isAvailable());
@@ -98,7 +98,7 @@ void tst_QAudioProbe::testNullService()
     QVERIFY(!probe.setSource(recorder));
     QVERIFY(!probe.isActive());
     delete recorder;
-    recorder = 0;
+    recorder = nullptr;
     QVERIFY(!probe.isActive());
 }
 
@@ -116,7 +116,7 @@ void tst_QAudioProbe::testNullControl()
     QVERIFY(!probe.setSource(recorder));
     QVERIFY(!probe.isActive());
     delete recorder;
-    recorder = 0;
+    recorder = nullptr;
     QVERIFY(!probe.isActive());
 }
 
@@ -129,7 +129,7 @@ void tst_QAudioProbe::testRecorder()
     QVERIFY(!probe.isActive());
     QVERIFY(probe.setSource(recorder));
     QVERIFY(probe.isActive());
-    probe.setSource((QMediaRecorder*)0);
+    probe.setSource((QMediaRecorder*)nullptr);
     QVERIFY(!probe.isActive());
 }
 
@@ -144,9 +144,9 @@ void tst_QAudioProbe::testRecorderDeleteRecorder()
     QVERIFY(probe.isActive());
 
     delete recorder;
-    recorder = 0;
+    recorder = nullptr;
     QVERIFY(!probe.isActive());
-    probe.setSource((QMediaRecorder*)0);
+    probe.setSource((QMediaRecorder*)nullptr);
     QVERIFY(!probe.isActive());
 }
 
@@ -166,14 +166,14 @@ void tst_QAudioProbe::testRecorderDeleteProbe()
 
 void tst_QAudioProbe::testMediaObject()
 {
-    QMediaObject *object = new MockMediaObject(0, mockMediaRecorderService);
+    QMediaObject *object = new MockMediaObject(nullptr, mockMediaRecorderService);
     QVERIFY(object->isAvailable());
 
     QAudioProbe probe;
     QVERIFY(!probe.isActive());
     QVERIFY(probe.setSource(object));
     QVERIFY(probe.isActive());
-    probe.setSource((QMediaObject*)0);
+    probe.setSource((QMediaObject*)nullptr);
     QVERIFY(!probe.isActive());
     delete object;
 }
diff --git a/tests/auto/unit/qaudiorecorder/tst_qaudiorecorder.cpp b/tests/auto/unit/qaudiorecorder/tst_qaudiorecorder.cpp
index cdee19e7e..7c0b69ad9 100644
--- a/tests/auto/unit/qaudiorecorder/tst_qaudiorecorder.cpp
+++ b/tests/auto/unit/qaudiorecorder/tst_qaudiorecorder.cpp
@@ -72,7 +72,7 @@ void tst_QAudioRecorder::init()
 {
     mockMediaRecorderService = new MockMediaRecorderService(this, new MockMediaRecorderControl(this));
     mockProvider = new MockMediaServiceProvider(mockMediaRecorderService);
-    audiosource = 0;
+    audiosource = nullptr;
 
     QMediaServiceProvider::setDefaultServiceProvider(mockProvider);
 }
@@ -82,14 +82,14 @@ void tst_QAudioRecorder::cleanup()
     delete mockMediaRecorderService;
     delete mockProvider;
     delete audiosource;
-    mockMediaRecorderService = 0;
-    mockProvider = 0;
-    audiosource = 0;
+    mockMediaRecorderService = nullptr;
+    mockProvider = nullptr;
+    audiosource = nullptr;
 }
 
 void tst_QAudioRecorder::testNullService()
 {
-    mockProvider->service = 0;
+    mockProvider->service = nullptr;
     QAudioRecorder source;
 
     QVERIFY(!source.isAvailable());
diff --git a/tests/auto/unit/qcamera/tst_qcamera.cpp b/tests/auto/unit/qcamera/tst_qcamera.cpp
index 5f8f40eb0..b8606167e 100644
--- a/tests/auto/unit/qcamera/tst_qcamera.cpp
+++ b/tests/auto/unit/qcamera/tst_qcamera.cpp
@@ -225,7 +225,7 @@ void tst_QCamera::testSimpleCameraExposure()
     provider->service = mockSimpleCameraService;
     QCamera camera;
     QCameraExposure *cameraExposure = camera.exposure();
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
     QVERIFY(!cameraExposure->isExposureModeSupported(QCameraExposure::ExposureAuto));
     QCOMPARE(cameraExposure->exposureMode(), QCameraExposure::ExposureAuto);
@@ -270,7 +270,7 @@ void tst_QCamera::testSimpleCameraFocus()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
 
     QVERIFY(!cameraFocus->isFocusModeSupported(QCameraFocus::AutoFocus));
     QVERIFY(!cameraFocus->isFocusModeSupported(QCameraFocus::ContinuousFocus));
@@ -531,7 +531,7 @@ void tst_QCamera::testCameraExposure()
     QCamera camera;
 
     QCameraExposure *cameraExposure = camera.exposure();
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
     QVERIFY(cameraExposure->isExposureModeSupported(QCameraExposure::ExposureAuto));
     QCOMPARE(cameraExposure->exposureMode(), QCameraExposure::ExposureAuto);
@@ -674,7 +674,7 @@ void tst_QCamera::testCameraFocus()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
 
     QVERIFY(cameraFocus->isFocusModeSupported(QCameraFocus::AutoFocus));
     QVERIFY(cameraFocus->isFocusModeSupported(QCameraFocus::ContinuousFocus));
@@ -1149,7 +1149,7 @@ void tst_QCamera::testSupportedViewfinderResolutions_data()
 {
     // see mockcameraviewfindersettingscontrol.h for expected values
 
-    typedef QList<QSize> SizeList;
+    using SizeList = QList<QSize>;
     ViewfinderSettingsBuilder builder;
 
     QTest::addColumn<QCameraViewfinderSettings>("settings");
@@ -1256,7 +1256,7 @@ void tst_QCamera::testSupportedViewfinderFrameRateRanges_data()
 {
     // see mockcameraviewfindersettingscontrol.h for expected values
 
-    typedef QList<QCamera::FrameRateRange> RangeList;
+    using RangeList = QList<QCamera::FrameRateRange>;
     ViewfinderSettingsBuilder builder;
 
     QTest::addColumn<QCameraViewfinderSettings>("settings");
@@ -1335,7 +1335,7 @@ void tst_QCamera::testSupportedViewfinderPixelFormats_data()
 {
     // see mockcameraviewfindersettingscontrol.h for expected values
 
-    typedef QList<QVideoFrame::PixelFormat> FormatList;
+    using FormatList = QList<QVideoFrame::PixelFormat>;
     ViewfinderSettingsBuilder builder;
 
     QTest::addColumn<QCameraViewfinderSettings>("settings");
@@ -1581,7 +1581,7 @@ void tst_QCamera::testSetVideoOutput()
     QCOMPARE(mockCameraService->rendererRef, 1);
 
     camera.setViewfinder(reinterpret_cast<QAbstractVideoSurface *>(0));
-    QVERIFY(mockCameraService->rendererControl->surface() == 0);
+    QVERIFY(mockCameraService->rendererControl->surface() == nullptr);
 
     //rendererControl is released
     QCOMPARE(mockCameraService->rendererRef, 0);
@@ -1591,7 +1591,7 @@ void tst_QCamera::testSetVideoOutput()
     QCOMPARE(mockCameraService->rendererRef, 1);
 
     camera.setViewfinder(reinterpret_cast<QVideoWidget *>(0));
-    QVERIFY(mockCameraService->rendererControl->surface() == 0);
+    QVERIFY(mockCameraService->rendererControl->surface() == nullptr);
     //rendererControl is released
     QCOMPARE(mockCameraService->rendererRef, 0);
 
@@ -1605,7 +1605,7 @@ void tst_QCamera::testSetVideoOutputNoService()
 {
     MockVideoSurface surface;
 
-    provider->service = 0;
+    provider->service = nullptr;
     QCamera camera;
 
     camera.setViewfinder(&surface);
@@ -1623,7 +1623,7 @@ void tst_QCamera::testSetVideoOutputNoControl()
     QCamera camera;
 
     camera.setViewfinder(&surface);
-    QVERIFY(service.rendererControl->surface() == 0);
+    QVERIFY(service.rendererControl->surface() == nullptr);
 }
 
 void tst_QCamera::testSetVideoOutputDestruction()
@@ -1638,7 +1638,7 @@ void tst_QCamera::testSetVideoOutputDestruction()
         QVERIFY(service.rendererControl->surface() == &surface);
         QCOMPARE(service.rendererRef, 1);
     }
-    QVERIFY(service.rendererControl->surface() == 0);
+    QVERIFY(service.rendererControl->surface() == nullptr);
     QCOMPARE(service.rendererRef, 0);
 }
 
@@ -1667,7 +1667,7 @@ void tst_QCamera::testEnumDebug()
 void tst_QCamera::testCameraControl()
 {
     MockCameraControl *m_cameraControl=new MockCameraControl(this);
-    QVERIFY(m_cameraControl != NULL);
+    QVERIFY(m_cameraControl != nullptr);
 }
 
 void tst_QCamera::testConstructor()
@@ -1822,7 +1822,7 @@ void tst_QCamera::testQCameraIsAvailable()
 
 void tst_QCamera::testQCameraIsNotAvailable()
 {
-    provider->service = 0;
+    provider->service = nullptr;
     QCamera camera("random");
 
     QCOMPARE(camera.error(), QCamera::ServiceMissingError);
@@ -2279,7 +2279,7 @@ void tst_QCamera::testCameraFocusIsAvailable()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
     QVERIFY(cameraFocus->isAvailable());
 }
 
@@ -2290,7 +2290,7 @@ void tst_QCamera::testFocusModes()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
     QVERIFY(!cameraFocus->isFocusModeSupported(QCameraFocus::HyperfocalFocus));
     QVERIFY(!cameraFocus->isFocusModeSupported(QCameraFocus::MacroFocus));
     QCOMPARE(cameraFocus->focusMode(), QCameraFocus::AutoFocus);
@@ -2307,7 +2307,7 @@ void tst_QCamera::testOpticalAndDigitalZoomChanged()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
     QSignalSpy spy1(cameraFocus,SIGNAL(digitalZoomChanged(qreal)));
     QSignalSpy spy2(cameraFocus,SIGNAL(opticalZoomChanged(qreal)));
     QVERIFY(spy1.count() == 0);
@@ -2322,7 +2322,7 @@ void tst_QCamera::testMaxDigitalZoomChangedSignal()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
     QSignalSpy spy(cameraFocus,SIGNAL(maximumDigitalZoomChanged(qreal)));
     QVERIFY(spy.count() == 0);
     cameraFocus->zoomTo(5.0,6.0);
@@ -2334,7 +2334,7 @@ void tst_QCamera::testMaxOpticalZoomChangedSignal()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
     QSignalSpy spy(cameraFocus,SIGNAL(maximumOpticalZoomChanged(qreal)));
     QVERIFY(spy.count() == 0);
     cameraFocus->zoomTo(5.0,6.0);
@@ -2346,7 +2346,7 @@ void tst_QCamera::testfocusZonesChangedSignal()
     QCamera camera;
 
     QCameraFocus *cameraFocus = camera.focus();
-    QVERIFY(cameraFocus != 0);
+    QVERIFY(cameraFocus != nullptr);
 
     QSignalSpy spy(cameraFocus,SIGNAL(focusZonesChanged()));
     cameraFocus->setCustomFocusPoint(QPointF(0.1, 0.1));
@@ -2365,7 +2365,7 @@ void tst_QCamera::testSignalApertureChanged()
     QCamera camera;
 
     QCameraExposure *cameraExposure = camera.exposure(); //create camera expose instance
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
     QSignalSpy spyApertureChanged(cameraExposure , SIGNAL(apertureChanged(qreal)));
     QSignalSpy spyApertureRangeChanged(cameraExposure , SIGNAL(apertureRangeChanged()));
@@ -2384,7 +2384,7 @@ void tst_QCamera::testSignalExposureCompensationChanged()
     QCamera camera;
 
     QCameraExposure *cameraExposure = camera.exposure(); //create camera expose instance
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
     QSignalSpy spyExposureCompensationChanged(cameraExposure , SIGNAL(exposureCompensationChanged(qreal)));
 
@@ -2412,7 +2412,7 @@ void tst_QCamera::testSignalIsoSensitivityChanged()
     QCamera camera;
 
     QCameraExposure *cameraExposure = camera.exposure(); //create camera expose instance
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
     QSignalSpy spyisoSensitivityChanged(cameraExposure , SIGNAL(isoSensitivityChanged(int)));
 
@@ -2428,7 +2428,7 @@ void tst_QCamera::testSignalShutterSpeedChanged()
     QCamera camera;
 
     QCameraExposure *cameraExposure = camera.exposure(); //create camera expose instance
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
     QSignalSpy spySignalShutterSpeedChanged(cameraExposure , SIGNAL(shutterSpeedChanged(qreal)));
     QSignalSpy spySignalShutterSpeedRangeChanged(cameraExposure , SIGNAL(shutterSpeedRangeChanged()));
@@ -2447,7 +2447,7 @@ void tst_QCamera::testSignalFlashReady()
     QCamera camera;
 
     QCameraExposure *cameraExposure = camera.exposure(); //create camera expose instance
-    QVERIFY(cameraExposure != 0);
+    QVERIFY(cameraExposure != nullptr);
 
 
     QSignalSpy spyflashReady(cameraExposure,SIGNAL(flashReady(bool)));
diff --git a/tests/auto/unit/qcameraimagecapture/tst_qcameraimagecapture.cpp b/tests/auto/unit/qcameraimagecapture/tst_qcameraimagecapture.cpp
index 5340706fc..6b2aae367 100644
--- a/tests/auto/unit/qcameraimagecapture/tst_qcameraimagecapture.cpp
+++ b/tests/auto/unit/qcameraimagecapture/tst_qcameraimagecapture.cpp
@@ -59,23 +59,23 @@ class NullService: public QMediaService
     Q_OBJECT
 
 public:
-    NullService(): QMediaService(0)
+    NullService(): QMediaService(nullptr)
     {
 
     }
 
-    ~NullService()
+    ~NullService() override
     {
 
     }
 
-    QMediaControl* requestControl(const char *iid)
+    QMediaControl* requestControl(const char *iid) override
     {
         Q_UNUSED(iid);
-        return 0;
+        return nullptr;
     }
 
-    void releaseControl(QMediaControl*) {}
+    void releaseControl(QMediaControl*) override {}
 
 };
 
@@ -128,7 +128,7 @@ void tst_QCameraImageCapture::init()
 void tst_QCameraImageCapture::cleanup()
 {
     delete mockcameraservice;
-    mockcameraservice = 0;
+    mockcameraservice = nullptr;
 }
 
 void tst_QCameraImageCapture::cleanupTestCase()
@@ -151,7 +151,7 @@ void tst_QCameraImageCapture::mediaObject()
     provider->service = &mymockcameraservice;
     QCamera camera;
     QCameraImageCapture imageCapture(&camera);
-    QVERIFY(imageCapture.mediaObject() == NULL);
+    QVERIFY(imageCapture.mediaObject() == nullptr);
 
     provider->service = mockcameraservice;
     QCamera camera1;
@@ -174,7 +174,7 @@ void tst_QCameraImageCapture::deleteMediaObject()
     delete provider->service;
 
     //capture should detach from camera
-    QVERIFY(capture->mediaObject() == 0);
+    QVERIFY(capture->mediaObject() == nullptr);
     QVERIFY(!capture->isAvailable());
 
     capture->capture();
diff --git a/tests/auto/unit/qcameraviewfinder/tst_qcameraviewfinder.cpp b/tests/auto/unit/qcameraviewfinder/tst_qcameraviewfinder.cpp
index 69f1b9780..270c60013 100644
--- a/tests/auto/unit/qcameraviewfinder/tst_qcameraviewfinder.cpp
+++ b/tests/auto/unit/qcameraviewfinder/tst_qcameraviewfinder.cpp
@@ -76,7 +76,7 @@ void tst_QCameraViewFinder::cleanupTestCase()
 void tst_QCameraViewFinder::testConstructor()
 {
     /* Verify whether the object is created or not */
-    QVERIFY(viewFinder != NULL);
+    QVERIFY(viewFinder != nullptr);
     QCOMPARE(viewFinder->isVisible(),false);
     QCOMPARE(viewFinder->isEnabled(),true);
     viewFinder->show();
@@ -84,7 +84,7 @@ void tst_QCameraViewFinder::testConstructor()
 
 void tst_QCameraViewFinder::testMediaObject()
 {
-    QVERIFY(viewFinder != NULL);
+    QVERIFY(viewFinder != nullptr);
     viewFinder->show();
     /* Sets the QVideoWidget  based camera viewfinder.*/
     camera->setViewfinder(viewFinder);
diff --git a/tests/auto/unit/qcamerawidgets/tst_qcamerawidgets.cpp b/tests/auto/unit/qcamerawidgets/tst_qcamerawidgets.cpp
index 11221bf09..cb901f457 100644
--- a/tests/auto/unit/qcamerawidgets/tst_qcamerawidgets.cpp
+++ b/tests/auto/unit/qcamerawidgets/tst_qcamerawidgets.cpp
@@ -93,7 +93,7 @@ void tst_QCameraWidgets::init()
 void tst_QCameraWidgets::cleanup()
 {
     delete mockCameraService;
-    provider->service = 0;
+    provider->service = nullptr;
 }
 
 
@@ -225,34 +225,34 @@ void tst_QCameraWidgets::testSetVideoOutput()
     QVERIFY(widget.mediaObject() == &camera);
 
     camera.setViewfinder(&item);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
     QVERIFY(item.mediaObject() == &camera);
 
     camera.setViewfinder(reinterpret_cast<QVideoWidget *>(0));
-    QVERIFY(item.mediaObject() == 0);
+    QVERIFY(item.mediaObject() == nullptr);
 
     camera.setViewfinder(&widget);
     QVERIFY(widget.mediaObject() == &camera);
 
     camera.setViewfinder(reinterpret_cast<QGraphicsVideoItem *>(0));
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 
     camera.setViewfinder(&surface);
     QVERIFY(mockCameraService->rendererControl->surface() == &surface);
 
     camera.setViewfinder(reinterpret_cast<QAbstractVideoSurface *>(0));
-    QVERIFY(mockCameraService->rendererControl->surface() == 0);
+    QVERIFY(mockCameraService->rendererControl->surface() == nullptr);
 
     camera.setViewfinder(&surface);
     QVERIFY(mockCameraService->rendererControl->surface() == &surface);
 
     camera.setViewfinder(&widget);
-    QVERIFY(mockCameraService->rendererControl->surface() == 0);
+    QVERIFY(mockCameraService->rendererControl->surface() == nullptr);
     QVERIFY(widget.mediaObject() == &camera);
 
     camera.setViewfinder(&surface);
     QVERIFY(mockCameraService->rendererControl->surface() == &surface);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 }
 
 
@@ -262,14 +262,14 @@ void tst_QCameraWidgets::testSetVideoOutputNoService()
     QGraphicsVideoItem item;
     MockVideoSurface surface;
 
-    provider->service = 0;
+    provider->service = nullptr;
     QCamera camera;
 
     camera.setViewfinder(&widget);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 
     camera.setViewfinder(&item);
-    QVERIFY(item.mediaObject() == 0);
+    QVERIFY(item.mediaObject() == nullptr);
 
     camera.setViewfinder(&surface);
     // Nothing we can verify here other than it doesn't assert.
@@ -287,13 +287,13 @@ void tst_QCameraWidgets::testSetVideoOutputNoControl()
     QCamera camera;
 
     camera.setViewfinder(&widget);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 
     camera.setViewfinder(&item);
-    QVERIFY(item.mediaObject() == 0);
+    QVERIFY(item.mediaObject() == nullptr);
 
     camera.setViewfinder(&surface);
-    QVERIFY(mockCameraService->rendererControl->surface() == 0);
+    QVERIFY(mockCameraService->rendererControl->surface() == nullptr);
 }
 
 QTEST_MAIN(tst_QCameraWidgets)
diff --git a/tests/auto/unit/qdeclarativeaudio/tst_qdeclarativeaudio.cpp b/tests/auto/unit/qdeclarativeaudio/tst_qdeclarativeaudio.cpp
index ea1b37d4d..ea05f116a 100644
--- a/tests/auto/unit/qdeclarativeaudio/tst_qdeclarativeaudio.cpp
+++ b/tests/auto/unit/qdeclarativeaudio/tst_qdeclarativeaudio.cpp
@@ -93,26 +93,15 @@ class QtTestMediaPlayerControl : public QMediaPlayerControl
 {
     Q_OBJECT
 public:
-    QtTestMediaPlayerControl(QObject *parent = 0)
+    QtTestMediaPlayerControl(QObject *parent = nullptr)
         : QMediaPlayerControl(parent)
-        , m_state(QMediaPlayer::StoppedState)
-        , m_mediaStatus(QMediaPlayer::NoMedia)
-        , m_duration(0)
-        , m_position(0)
-        , m_playbackRate(1.0)
-        , m_volume(100)
-        , m_bufferStatus(0)
-        , m_muted(false)
-        , m_audioAvailable(false)
-        , m_videoAvailable(false)
-        , m_seekable(false)
     {
     }
 
-    QMediaPlayer::State state() const { return m_state; }
+    [[nodiscard]] QMediaPlayer::State state() const override { return m_state; }
     void updateState(QMediaPlayer::State state) { emit stateChanged(m_state = state); }
 
-    QMediaPlayer::MediaStatus mediaStatus() const { return m_mediaStatus; }
+    [[nodiscard]] QMediaPlayer::MediaStatus mediaStatus() const override { return m_mediaStatus; }
     void updateMediaStatus(QMediaPlayer::MediaStatus status) {
         emit mediaStatusChanged(m_mediaStatus = status); }
     void updateMediaStatus(QMediaPlayer::MediaStatus status, QMediaPlayer::State state)
@@ -124,39 +113,39 @@ public:
         emit stateChanged(m_state);
     }
 
-    qint64 duration() const { return m_duration; }
+    [[nodiscard]] qint64 duration() const override { return m_duration; }
     void setDuration(qint64 duration) { emit durationChanged(m_duration = duration); }
 
-    qint64 position() const { return m_position; }
-    void setPosition(qint64 position) { emit positionChanged(m_position = position); }
+    [[nodiscard]] qint64 position() const override { return m_position; }
+    void setPosition(qint64 position) override { emit positionChanged(m_position = position); }
 
-    int volume() const { return m_volume; }
-    void setVolume(int volume) { emit volumeChanged(m_volume = volume); }
+    [[nodiscard]] int volume() const override { return m_volume; }
+    void setVolume(int volume) override { emit volumeChanged(m_volume = volume); }
 
-    bool isMuted() const { return m_muted; }
-    void setMuted(bool muted) { emit mutedChanged(m_muted = muted); }
+    [[nodiscard]] bool isMuted() const override { return m_muted; }
+    void setMuted(bool muted) override { emit mutedChanged(m_muted = muted); }
 
-    int bufferStatus() const { return m_bufferStatus; }
+    [[nodiscard]] int bufferStatus() const override { return m_bufferStatus; }
     void setBufferStatus(int status) { emit bufferStatusChanged(m_bufferStatus = status); }
 
-    bool isAudioAvailable() const { return m_audioAvailable; }
+    [[nodiscard]] bool isAudioAvailable() const override { return m_audioAvailable; }
     void setAudioAvailable(bool available) {
         emit audioAvailableChanged(m_audioAvailable = available); }
-    bool isVideoAvailable() const { return m_videoAvailable; }
+    [[nodiscard]] bool isVideoAvailable() const override { return m_videoAvailable; }
     void setVideoAvailable(bool available) {
         emit videoAvailableChanged(m_videoAvailable = available); }
 
-    bool isSeekable() const { return m_seekable; }
+    [[nodiscard]] bool isSeekable() const override { return m_seekable; }
     void setSeekable(bool seekable) { emit seekableChanged(m_seekable = seekable); }
 
-    QMediaTimeRange availablePlaybackRanges() const { return QMediaTimeRange(); }
+    [[nodiscard]] QMediaTimeRange availablePlaybackRanges() const override { return QMediaTimeRange(); }
 
-    qreal playbackRate() const { return m_playbackRate; }
-    void setPlaybackRate(qreal rate) { emit playbackRateChanged(m_playbackRate = rate); }
+    [[nodiscard]] qreal playbackRate() const override { return m_playbackRate; }
+    void setPlaybackRate(qreal rate) override { emit playbackRateChanged(m_playbackRate = rate); }
 
-    QMediaContent media() const { return m_media; }
-    const QIODevice *mediaStream() const { return 0; }
-    void setMedia(const QMediaContent &media, QIODevice *)
+    [[nodiscard]] QMediaContent media() const override { return m_media; }
+    [[nodiscard]] const QIODevice *mediaStream() const override { return nullptr; }
+    void setMedia(const QMediaContent &media, QIODevice *) override
     {
         m_media = media;
 
@@ -168,31 +157,31 @@ public:
         emit mediaStatusChanged(m_mediaStatus);
     }
 
-    void play()
+    void play() override
     {
         m_state = QMediaPlayer::PlayingState;
         if (m_mediaStatus == QMediaPlayer::EndOfMedia)
             updateMediaStatus(QMediaPlayer::LoadedMedia);
         emit stateChanged(m_state);
     }
-    void pause() { emit stateChanged(m_state = QMediaPlayer::PausedState); }
-    void stop() { emit stateChanged(m_state = QMediaPlayer::StoppedState); }
+    void pause() override { emit stateChanged(m_state = QMediaPlayer::PausedState); }
+    void stop() override { emit stateChanged(m_state = QMediaPlayer::StoppedState); }
 
     void emitError(QMediaPlayer::Error err, const QString &errorString) {
         emit error(err, errorString); }
 
 private:
-    QMediaPlayer::State m_state;
-    QMediaPlayer::MediaStatus m_mediaStatus;
-    qint64 m_duration;
-    qint64 m_position;
-    qreal m_playbackRate;
-    int m_volume;
-    int m_bufferStatus;
-    bool m_muted;
-    bool m_audioAvailable;
-    bool m_videoAvailable;
-    bool m_seekable;
+    QMediaPlayer::State m_state = QMediaPlayer::StoppedState;
+    QMediaPlayer::MediaStatus m_mediaStatus = QMediaPlayer::NoMedia;
+    qint64 m_duration = 0;
+    qint64 m_position = 0;
+    qreal m_playbackRate = 1.0;
+    int m_volume = 100;
+    int m_bufferStatus = 0;
+    bool m_muted = false;
+    bool m_audioAvailable = false;
+    bool m_videoAvailable = false;
+    bool m_seekable = false;
     QMediaContent m_media;
 };
 
@@ -200,18 +189,18 @@ class QtTestMetaDataControl : public QMetaDataReaderControl
 {
     Q_OBJECT
 public:
-    QtTestMetaDataControl(QObject *parent = 0)
+    QtTestMetaDataControl(QObject *parent = nullptr)
         : QMetaDataReaderControl(parent)
     {
     }
 
-    bool isMetaDataAvailable() const { return true; }
+    [[nodiscard]] bool isMetaDataAvailable() const override { return true; }
 
-    QVariant metaData(const QString &key) const { return m_metaData.value(key); }
+    [[nodiscard]] QVariant metaData(const QString &key) const override { return m_metaData.value(key); }
     void setMetaData(const QString &key, const QVariant &value) {
         m_metaData.insert(key, value); emit metaDataChanged(); }
 
-    QStringList availableMetaData() const { return m_metaData.keys(); }
+    [[nodiscard]] QStringList availableMetaData() const override { return m_metaData.keys(); }
 
 private:
     QMap<QString, QVariant> m_metaData;
@@ -231,17 +220,17 @@ public:
     {
     }
 
-    QMediaControl *requestControl(const char *name)
+    QMediaControl *requestControl(const char *name) override
     {
         if (qstrcmp(name, QMediaPlayerControl_iid) == 0)
             return playerControl;
         else if (qstrcmp(name, QMetaDataReaderControl_iid) == 0)
             return metaDataControl;
         else
-            return 0;
+            return nullptr;
     }
 
-    void releaseControl(QMediaControl *) {}
+    void releaseControl(QMediaControl *) override {}
 
     QtTestMediaPlayerControl *playerControl;
     QtTestMetaDataControl *metaDataControl;
@@ -271,19 +260,19 @@ public:
         setDefaultServiceProvider(this);
     }
 
-    ~QtTestMediaServiceProvider()
+    ~QtTestMediaServiceProvider() override
     {
-        setDefaultServiceProvider(0);
+        setDefaultServiceProvider(nullptr);
     }
 
-    QMediaService *requestService(const QByteArray &type)
+    QMediaService *requestService(const QByteArray &type) override
     {
         requestedService = type;
 
         return service;
     }
 
-    void releaseService(QMediaService *) {}
+    void releaseService(QMediaService *) override {}
 
     inline QtTestMediaPlayerControl *playerControl() { return service->playerControl; }
     inline QtTestMetaDataControl *metaDataControl() { return service->metaDataControl; }
@@ -301,7 +290,7 @@ void tst_QDeclarativeAudio::initTestCase()
 void tst_QDeclarativeAudio::nullPlayerControl()
 {
     QtTestMetaDataControl metaDataControl;
-    QtTestMediaServiceProvider provider(0, &metaDataControl);
+    QtTestMediaServiceProvider provider(nullptr, &metaDataControl);
 
     QDeclarativeAudio audio;
     audio.classBegin();
@@ -344,7 +333,7 @@ void tst_QDeclarativeAudio::nullPlayerControl()
 void tst_QDeclarativeAudio::nullMetaDataControl()
 {
     QtTestMediaPlayerControl playerControl;
-    QtTestMediaServiceProvider provider(&playerControl, 0);
+    QtTestMediaServiceProvider provider(&playerControl, nullptr);
 
     QDeclarativeAudio audio;
     audio.classBegin();
@@ -355,7 +344,7 @@ void tst_QDeclarativeAudio::nullMetaDataControl()
 
 void tst_QDeclarativeAudio::nullService()
 {
-    QtTestMediaServiceProvider provider(0);
+    QtTestMediaServiceProvider provider(nullptr);
 
     QDeclarativeAudio audio;
     audio.classBegin();
@@ -1197,7 +1186,7 @@ int tst_QDeclarativeAudio::keyToValue(const QMetaEnum &enumeration, const char *
 struct Surface : QAbstractVideoSurface
 {
     Surface(QObject *parent = nullptr) : QAbstractVideoSurface(parent) { }
-    QList<QVideoFrame::PixelFormat> supportedPixelFormats(QAbstractVideoBuffer::HandleType) const override
+    [[nodiscard]] QList<QVideoFrame::PixelFormat> supportedPixelFormats(QAbstractVideoBuffer::HandleType) const override
     {
         return QList<QVideoFrame::PixelFormat>() << QVideoFrame::Format_RGB32;
     }
@@ -1208,7 +1197,7 @@ struct Surface : QAbstractVideoSurface
 void tst_QDeclarativeAudio::videoOutput()
 {
     QtTestMediaPlayerControl playerControl;
-    QtTestMediaServiceProvider provider(&playerControl, 0);
+    QtTestMediaServiceProvider provider(&playerControl, nullptr);
 
     QDeclarativeAudio audio;
     QSignalSpy spy(&audio, &QDeclarativeAudio::videoOutputChanged);
diff --git a/tests/auto/unit/qgraphicsvideoitem/tst_qgraphicsvideoitem.cpp b/tests/auto/unit/qgraphicsvideoitem/tst_qgraphicsvideoitem.cpp
index 41805f49a..ecf89eaed 100644
--- a/tests/auto/unit/qgraphicsvideoitem/tst_qgraphicsvideoitem.cpp
+++ b/tests/auto/unit/qgraphicsvideoitem/tst_qgraphicsvideoitem.cpp
@@ -79,16 +79,11 @@ Q_DECLARE_METATYPE(Qt::AspectRatioMode)
 class QtTestRendererControl : public QVideoRendererControl
 {
 public:
-    QtTestRendererControl()
-        : m_surface(0)
-    {
-    }
-
-    QAbstractVideoSurface *surface() const { return m_surface; }
-    void setSurface(QAbstractVideoSurface *surface) { m_surface = surface; }
+    [[nodiscard]] QAbstractVideoSurface *surface() const override { return m_surface; }
+    void setSurface(QAbstractVideoSurface *surface) override { m_surface = surface; }
 
 private:
-    QAbstractVideoSurface *m_surface;
+    QAbstractVideoSurface *m_surface = nullptr;
 };
 
 class QtTestVideoService : public QMediaService
@@ -97,29 +92,29 @@ class QtTestVideoService : public QMediaService
 public:
     QtTestVideoService(
             QtTestRendererControl *renderer)
-        : QMediaService(0)
+        : QMediaService(nullptr)
         , rendererRef(0)
         , rendererControl(renderer)
     {
     }
 
-    ~QtTestVideoService()
+    ~QtTestVideoService() override
     {
         delete rendererControl;
     }
 
-    QMediaControl *requestControl(const char *name)
+    QMediaControl *requestControl(const char *name) override
     {
         if (qstrcmp(name, QVideoRendererControl_iid) == 0 && rendererControl) {
             rendererRef += 1;
 
             return rendererControl;
         } else {
-            return 0;
+            return nullptr;
         }
     }
 
-    void releaseControl(QMediaControl *control)
+    void releaseControl(QMediaControl *control) override
     {
         Q_ASSERT(control);
 
@@ -127,7 +122,7 @@ public:
             rendererRef -= 1;
 
             if (rendererRef == 0)
-                rendererControl->setSurface(0);
+                rendererControl->setSurface(nullptr);
         }
     }
 
@@ -140,18 +135,18 @@ class QtTestVideoObject : public QMediaObject
     Q_OBJECT
 public:
     QtTestVideoObject(QtTestRendererControl *renderer)
-        : QMediaObject(0, new QtTestVideoService(renderer))
+        : QMediaObject(nullptr, new QtTestVideoService(renderer))
     {
         testService = qobject_cast<QtTestVideoService*>(service());
     }
 
     QtTestVideoObject(QtTestVideoService *service):
-        QMediaObject(0, service),
+        QMediaObject(nullptr, service),
         testService(service)
     {
     }
 
-    ~QtTestVideoObject()
+    ~QtTestVideoObject() override
     {
         delete testService;
     }
@@ -162,13 +157,12 @@ public:
 class QtTestGraphicsVideoItem : public QGraphicsVideoItem
 {
 public:
-    QtTestGraphicsVideoItem(QGraphicsItem *parent = 0)
+    QtTestGraphicsVideoItem(QGraphicsItem *parent = nullptr)
         : QGraphicsVideoItem(parent)
-        , m_paintCount(0)
     {
     }
 
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
     {
         ++m_paintCount;
 
@@ -186,13 +180,13 @@ public:
         return m_paintCount != paintCount;
     }
 
-    int paintCount() const
+    [[nodiscard]] int paintCount() const
     {
         return m_paintCount;
     }
 
 private:
-    int m_paintCount;
+    int m_paintCount = 0;
 };
 
 void tst_QGraphicsVideoItem::initTestCase()
@@ -202,14 +196,14 @@ void tst_QGraphicsVideoItem::initTestCase()
 
 void tst_QGraphicsVideoItem::nullObject()
 {
-    QGraphicsVideoItem item(0);
+    QGraphicsVideoItem item(nullptr);
 
     QVERIFY(item.boundingRect().isEmpty());
 }
 
 void tst_QGraphicsVideoItem::nullService()
 {
-    QtTestVideoService *service = 0;
+    QtTestVideoService *service = nullptr;
 
     QtTestVideoObject object(service);
 
@@ -229,7 +223,7 @@ void tst_QGraphicsVideoItem::nullService()
 
 void tst_QGraphicsVideoItem::noOutputs()
 {
-    QtTestRendererControl *control = 0;
+    QtTestRendererControl *control = nullptr;
     QtTestVideoObject object(control);
 
     QtTestGraphicsVideoItem *item = new QtTestGraphicsVideoItem;
@@ -256,7 +250,7 @@ void tst_QGraphicsVideoItem::serviceDestroyed()
     QCOMPARE(object.testService->rendererRef, 1);
 
     QtTestVideoService *service = object.testService;
-    object.testService = 0;
+    object.testService = nullptr;
 
     delete service;
 
@@ -274,7 +268,7 @@ void tst_QGraphicsVideoItem::mediaObjectDestroyed()
     QCOMPARE(object->testService->rendererRef, 1);
 
     delete object;
-    object = 0;
+    object = nullptr;
 
     QCOMPARE(item.mediaObject(), static_cast<QMediaObject *>(object));
     QVERIFY(item.boundingRect().isEmpty());
@@ -282,7 +276,7 @@ void tst_QGraphicsVideoItem::mediaObjectDestroyed()
 
 void tst_QGraphicsVideoItem::setMediaObject()
 {
-    QMediaObject *nullObject = 0;
+    QMediaObject *nullObject = nullptr;
     QtTestVideoObject object(new QtTestRendererControl);
 
     QGraphicsVideoItem item;
@@ -293,28 +287,28 @@ void tst_QGraphicsVideoItem::setMediaObject()
     object.bind(&item);
     QCOMPARE(item.mediaObject(), static_cast<QMediaObject *>(&object));
     QCOMPARE(object.testService->rendererRef, 1);
-    QVERIFY(object.testService->rendererControl->surface() == 0);
+    QVERIFY(object.testService->rendererControl->surface() == nullptr);
 
     {   // Surface setup is deferred until after the first paint.
         QImage image(320, 240, QImage::Format_RGB32);
         QPainter painter(&image);
 
-        item.paint(&painter, 0);
+        item.paint(&painter, nullptr);
     }
-    QVERIFY(object.testService->rendererControl->surface() != 0);
+    QVERIFY(object.testService->rendererControl->surface() != nullptr);
 
     object.unbind(&item);
     QCOMPARE(item.mediaObject(), nullObject);
 
     QCOMPARE(object.testService->rendererRef, 0);
-    QVERIFY(object.testService->rendererControl->surface() == 0);
+    QVERIFY(object.testService->rendererControl->surface() == nullptr);
 
     item.setVisible(false);
 
     object.bind(&item);
     QCOMPARE(item.mediaObject(), static_cast<QMediaObject *>(&object));
     QCOMPARE(object.testService->rendererRef, 1);
-    QVERIFY(object.testService->rendererControl->surface() != 0);
+    QVERIFY(object.testService->rendererControl->surface() != nullptr);
 }
 
 void tst_QGraphicsVideoItem::show()
@@ -325,14 +319,14 @@ void tst_QGraphicsVideoItem::show()
 
     // Graphics items are visible by default
     QCOMPARE(object.testService->rendererRef, 1);
-    QVERIFY(object.testService->rendererControl->surface() == 0);
+    QVERIFY(object.testService->rendererControl->surface() == nullptr);
 
     item->hide();
     QCOMPARE(object.testService->rendererRef, 1);
 
     item->show();
     QCOMPARE(object.testService->rendererRef, 1);
-    QVERIFY(object.testService->rendererControl->surface() == 0);
+    QVERIFY(object.testService->rendererControl->surface() == nullptr);
 
     QGraphicsScene graphicsScene;
     graphicsScene.addItem(item);
@@ -340,7 +334,7 @@ void tst_QGraphicsVideoItem::show()
     graphicsView.show();
 
     QVERIFY(item->paintCount() || item->waitForPaint(1));
-    QVERIFY(object.testService->rendererControl->surface() != 0);
+    QVERIFY(object.testService->rendererControl->surface() != nullptr);
 
     QVERIFY(item->boundingRect().isEmpty());
 
@@ -457,9 +451,9 @@ void tst_QGraphicsVideoItem::nativeSize()
         QImage image(320, 240, QImage::Format_RGB32);
         QPainter painter(&image);
 
-        item.paint(&painter, 0);
+        item.paint(&painter, nullptr);
     }
-    QVERIFY(object.testService->rendererControl->surface() != 0);
+    QVERIFY(object.testService->rendererControl->surface() != nullptr);
     QVERIFY(object.testService->rendererControl->surface()->start(format));
 
     QCoreApplication::processEvents();
@@ -598,9 +592,9 @@ void tst_QGraphicsVideoItem::boundingRect()
         QImage image(320, 240, QImage::Format_RGB32);
         QPainter painter(&image);
 
-        item.paint(&painter, 0);
+        item.paint(&painter, nullptr);
     }
-    QVERIFY(object.testService->rendererControl->surface() != 0);
+    QVERIFY(object.testService->rendererControl->surface() != nullptr);
     QVERIFY(object.testService->rendererControl->surface()->start(format));
 
     QCoreApplication::processEvents();
diff --git a/tests/auto/unit/qmediabindableinterface/tst_qmediabindableinterface.cpp b/tests/auto/unit/qmediabindableinterface/tst_qmediabindableinterface.cpp
index a7123cfe0..edac16b55 100644
--- a/tests/auto/unit/qmediabindableinterface/tst_qmediabindableinterface.cpp
+++ b/tests/auto/unit/qmediabindableinterface/tst_qmediabindableinterface.cpp
@@ -61,7 +61,7 @@ public:
         mockMetaDataControl = new MockMetaDataWriterControl(parent); //Creating the object for MetaData
     }
 
-    QMediaControl* requestControl(const char *name)
+    QMediaControl* requestControl(const char *name) override
     {
         if (hasControls && qstrcmp(name,QMediaRecorderControl_iid) == 0)
             return mockControl;
@@ -70,10 +70,10 @@ public:
         if (hasControls && qstrcmp(name, QMetaDataWriterControl_iid) == 0)
             return mockMetaDataControl;
 
-        return 0;
+        return nullptr;
     }
 
-    void releaseControl(QMediaControl*) {}
+    void releaseControl(QMediaControl*) override {}
     //Initialising the objects for the media
     QMediaControl *mockControl;
     QMediaContainerControl *mockContainerControl;
@@ -97,26 +97,26 @@ private slots:
 
     void testMediaObject() //Verifying the mediaobject api
     {
-        MockMediaRecorderControl recorderControl(0);
-        TestBindableService service(0, &recorderControl);
+        MockMediaRecorderControl recorderControl(nullptr);
+        TestBindableService service(nullptr, &recorderControl);
         service.mockMetaDataControl->populateMetaData();
-        MockMediaObject object(0, &service);
+        MockMediaObject object(nullptr, &service);
         QMediaRecorder recorder(&object);
         QMediaObject *obj = recorder.mediaObject();
-        QVERIFY(obj != NULL);
+        QVERIFY(obj != nullptr);
         QVERIFY(obj->isAvailable());
     }
 
     void testDestructor() //Invoking the destructor
     {
-        MockMediaRecorderControl recorderControl(0);
-        TestBindableService service(0, &recorderControl);
+        MockMediaRecorderControl recorderControl(nullptr);
+        TestBindableService service(nullptr, &recorderControl);
         service.mockMetaDataControl->populateMetaData();
-        MockMediaObject object(0, &service);
+        MockMediaObject object(nullptr, &service);
         QMediaRecorder *recorder = new QMediaRecorder(&object);
         QVERIFY(recorder->isAvailable());
         delete recorder;
-        recorder = NULL;
+        recorder = nullptr;
     }
 };
 
diff --git a/tests/auto/unit/qmediaobject/tst_qmediaobject.cpp b/tests/auto/unit/qmediaobject/tst_qmediaobject.cpp
index e475440d2..c4e847ab4 100644
--- a/tests/auto/unit/qmediaobject/tst_qmediaobject.cpp
+++ b/tests/auto/unit/qmediaobject/tst_qmediaobject.cpp
@@ -46,28 +46,26 @@ class QtTestMediaObjectService : public QMediaService
 {
     Q_OBJECT
 public:
-    QtTestMediaObjectService(QObject *parent = 0)
+    QtTestMediaObjectService(QObject *parent = nullptr)
         : QMediaService(parent)
-        , metaDataRef(0)
-        , hasMetaData(true)
     {
     }
 
-    QMediaControl *requestControl(const char *iid)
+    QMediaControl *requestControl(const char *iid) override
     {
         if (hasMetaData && qstrcmp(iid, QMetaDataReaderControl_iid) == 0)
             return &metaData;
         else
-            return 0;
+            return nullptr;
     }
 
-    void releaseControl(QMediaControl *)
+    void releaseControl(QMediaControl *) override
     {
     }
 
     MockMetaDataReaderControl metaData;
-    int metaDataRef;
-    bool hasMetaData;
+    int metaDataRef = 0;
+    bool hasMetaData = true;
 };
 
 QT_USE_NAMESPACE
@@ -104,21 +102,21 @@ class QtTestMediaObject : public QMediaObject
     Q_PROPERTY(int c READ c WRITE setC NOTIFY cChanged)
     Q_PROPERTY(int d READ d WRITE setD)
 public:
-    QtTestMediaObject(QMediaService *service = 0): QMediaObject(0, service), m_a(0), m_b(0), m_c(0), m_d(0) {}
+    QtTestMediaObject(QMediaService *service = nullptr): QMediaObject(nullptr, service) {}
 
     using QMediaObject::addPropertyWatch;
     using QMediaObject::removePropertyWatch;
 
-    int a() const { return m_a; }
+    [[nodiscard]] int a() const { return m_a; }
     void setA(int a) { m_a = a; }
 
-    int b() const { return m_b; }
+    [[nodiscard]] int b() const { return m_b; }
     void setB(int b) { m_b = b; }
 
-    int c() const { return m_c; }
+    [[nodiscard]] int c() const { return m_c; }
     void setC(int c) { m_c = c; }
 
-    int d() const { return m_d; }
+    [[nodiscard]] int d() const { return m_d; }
     void setD(int d) { m_d = d; }
 
 Q_SIGNALS:
@@ -127,10 +125,10 @@ Q_SIGNALS:
     void cChanged(int c);
 
 private:
-    int m_a;
-    int m_b;
-    int m_c;
-    int m_d;
+    int m_a = 0;
+    int m_b = 0;
+    int m_c = 0;
+    int m_d = 0;
 };
 
 void tst_QMediaObject::propertyWatch()
@@ -423,7 +421,7 @@ void tst_QMediaObject::metaData()
 void tst_QMediaObject::availability()
 {
     {
-        QtTestMediaObject nullObject(0);
+        QtTestMediaObject nullObject(nullptr);
         QCOMPARE(nullObject.isAvailable(), false);
         QCOMPARE(nullObject.availability(), QMultimedia::ServiceMissing);
     }
@@ -444,13 +442,13 @@ void tst_QMediaObject::availability()
 
      // Get service and Compare if it equal to the service passed as an argument in mediaObject1.
      QMediaService *service1 = mediaObject1.service();
-     QVERIFY(service1 != NULL);
+     QVERIFY(service1 != nullptr);
      QCOMPARE(service1,&service);
 
      // Create the mediaobject with empty service and verify that service() returns NULL.
      QtTestMediaObject mediaObject2;
      QMediaService *service2 = mediaObject2.service();
-     QVERIFY(service2 == NULL);
+     QVERIFY(service2 == nullptr);
 }
 
 QTEST_GUILESS_MAIN(tst_QMediaObject)
diff --git a/tests/auto/unit/qmediaplayer/tst_qmediaplayer.cpp b/tests/auto/unit/qmediaplayer/tst_qmediaplayer.cpp
index 57a010528..f6ae05885 100644
--- a/tests/auto/unit/qmediaplayer/tst_qmediaplayer.cpp
+++ b/tests/auto/unit/qmediaplayer/tst_qmediaplayer.cpp
@@ -211,10 +211,10 @@ void tst_QMediaPlayer::testNullService_data()
 
 void tst_QMediaPlayer::testNullService()
 {
-    mockProvider->service = 0;
+    mockProvider->service = nullptr;
     QMediaPlayer player;
 
-    const QIODevice *nullDevice = 0;
+    const QIODevice *nullDevice = nullptr;
 
     QCOMPARE(player.media(), QMediaContent());
     QCOMPARE(player.mediaStream(), nullDevice);
@@ -960,7 +960,7 @@ void tst_QMediaPlayer::testPlaylist()
         QCOMPARE(player->currentMedia(), content1);
     } //playlist should be detached now
 
-    QVERIFY(player->playlist() == 0);
+    QVERIFY(player->playlist() == nullptr);
     QCOMPARE(player->currentMedia(), QMediaContent());
 
     // Test when the player service encounters an invalid media, the player moves onto
@@ -1009,7 +1009,7 @@ void tst_QMediaPlayer::testDestructor()
     delete victim;
 
     //service is released
-    QVERIFY(mockProvider->service == 0);
+    QVERIFY(mockProvider->service == nullptr);
 
     mockProvider->deleteServiceOnRelease = false;
 }
@@ -1028,7 +1028,7 @@ void tst_QMediaPlayer::testSetVideoOutput()
     QCOMPARE(mockService->rendererRef, 1);
 
     player->setVideoOutput(reinterpret_cast<QAbstractVideoSurface *>(0));
-    QVERIFY(mockService->rendererControl->surface() == 0);
+    QVERIFY(mockService->rendererControl->surface() == nullptr);
 
     //rendererControl is released
     QCOMPARE(mockService->rendererRef, 0);
@@ -1038,7 +1038,7 @@ void tst_QMediaPlayer::testSetVideoOutput()
     QCOMPARE(mockService->rendererRef, 1);
 
     player->setVideoOutput(reinterpret_cast<QVideoWidget *>(0));
-    QVERIFY(mockService->rendererControl->surface() == 0);
+    QVERIFY(mockService->rendererControl->surface() == nullptr);
     //rendererControl is released
     QCOMPARE(mockService->rendererRef, 0);
 
@@ -1052,7 +1052,7 @@ void tst_QMediaPlayer::testSetVideoOutputNoService()
 {
     MockVideoSurface surface;
 
-    MockMediaServiceProvider provider(0, true);
+    MockMediaServiceProvider provider(nullptr, true);
     QMediaServiceProvider::setDefaultServiceProvider(&provider);
     QMediaPlayer player;
 
@@ -1072,7 +1072,7 @@ void tst_QMediaPlayer::testSetVideoOutputNoControl()
     QMediaPlayer player;
 
     player.setVideoOutput(&surface);
-    QVERIFY(service.rendererControl->surface() == 0);
+    QVERIFY(service.rendererControl->surface() == nullptr);
 }
 
 void tst_QMediaPlayer::testSetVideoOutputDestruction()
@@ -1084,7 +1084,7 @@ void tst_QMediaPlayer::testSetVideoOutputDestruction()
         QVERIFY(mockService->rendererControl->surface() == &surface);
         QCOMPARE(mockService->rendererRef, 1);
     }
-    QVERIFY(mockService->rendererControl->surface() == 0);
+    QVERIFY(mockService->rendererControl->surface() == nullptr);
     QCOMPARE(mockService->rendererRef, 0);
 }
 
diff --git a/tests/auto/unit/qmediaplayerwidgets/tst_qmediaplayerwidgets.cpp b/tests/auto/unit/qmediaplayerwidgets/tst_qmediaplayerwidgets.cpp
index 1e6a714fb..38607ca99 100644
--- a/tests/auto/unit/qmediaplayerwidgets/tst_qmediaplayerwidgets.cpp
+++ b/tests/auto/unit/qmediaplayerwidgets/tst_qmediaplayerwidgets.cpp
@@ -96,34 +96,34 @@ void tst_QMediaPlayerWidgets::testSetVideoOutput()
     QVERIFY(widget.mediaObject() == &player);
 
     player.setVideoOutput(&item);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
     QVERIFY(item.mediaObject() == &player);
 
     player.setVideoOutput(reinterpret_cast<QVideoWidget *>(0));
-    QVERIFY(item.mediaObject() == 0);
+    QVERIFY(item.mediaObject() == nullptr);
 
     player.setVideoOutput(&widget);
     QVERIFY(widget.mediaObject() == &player);
 
     player.setVideoOutput(reinterpret_cast<QGraphicsVideoItem *>(0));
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 
     player.setVideoOutput(&surface);
     QVERIFY(mockService->rendererControl->surface() == &surface);
 
     player.setVideoOutput(reinterpret_cast<QAbstractVideoSurface *>(0));
-    QVERIFY(mockService->rendererControl->surface() == 0);
+    QVERIFY(mockService->rendererControl->surface() == nullptr);
 
     player.setVideoOutput(&surface);
     QVERIFY(mockService->rendererControl->surface() == &surface);
 
     player.setVideoOutput(&widget);
-    QVERIFY(mockService->rendererControl->surface() == 0);
+    QVERIFY(mockService->rendererControl->surface() == nullptr);
     QVERIFY(widget.mediaObject() == &player);
 
     player.setVideoOutput(&surface);
     QVERIFY(mockService->rendererControl->surface() == &surface);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 }
 
 
@@ -133,14 +133,14 @@ void tst_QMediaPlayerWidgets::testSetVideoOutputNoService()
     QGraphicsVideoItem item;
     MockVideoSurface surface;
 
-    provider->service = 0;
+    provider->service = nullptr;
     QMediaPlayer player;
 
     player.setVideoOutput(&widget);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 
     player.setVideoOutput(&item);
-    QVERIFY(item.mediaObject() == 0);
+    QVERIFY(item.mediaObject() == nullptr);
 
     player.setVideoOutput(&surface);
     // Nothing we can verify here other than it doesn't assert.
@@ -161,13 +161,13 @@ void tst_QMediaPlayerWidgets::testSetVideoOutputNoControl()
     QMediaPlayer player;
 
     player.setVideoOutput(&widget);
-    QVERIFY(widget.mediaObject() == 0);
+    QVERIFY(widget.mediaObject() == nullptr);
 
     player.setVideoOutput(&item);
-    QVERIFY(item.mediaObject() == 0);
+    QVERIFY(item.mediaObject() == nullptr);
 
     player.setVideoOutput(&surface);
-    QVERIFY(service.rendererControl->surface() == 0);
+    QVERIFY(service.rendererControl->surface() == nullptr);
 }
 
 QTEST_MAIN(tst_QMediaPlayerWidgets)
diff --git a/tests/auto/unit/qmediapluginloader/tst_qmediapluginloader.cpp b/tests/auto/unit/qmediapluginloader/tst_qmediapluginloader.cpp
index f5081a42e..5a17785ba 100644
--- a/tests/auto/unit/qmediapluginloader/tst_qmediapluginloader.cpp
+++ b/tests/auto/unit/qmediapluginloader/tst_qmediapluginloader.cpp
@@ -73,7 +73,7 @@ void tst_QMediaPluginLoader::testInstance()
         QSKIP("No plug-ins available");
 
     for (const QString &key : keys)
-        QVERIFY(loader->instance(key) != 0);
+        QVERIFY(loader->instance(key) != nullptr);
 }
 
 void tst_QMediaPluginLoader::testInstances()
@@ -96,7 +96,7 @@ void tst_QMediaPluginLoader::testInvalidKey()
     if (loader->keys().contains(key))
         QSKIP("a plug-in includes the invalid key");
 
-    QVERIFY(loader->instance(key) == 0);
+    QVERIFY(loader->instance(key) == nullptr);
 
     // Test looking up the key hasn't inserted it into the list. See QMap::operator[].
     QVERIFY(!loader->keys().contains(key));
diff --git a/tests/auto/unit/qmediarecorder/tst_qmediarecorder.cpp b/tests/auto/unit/qmediarecorder/tst_qmediarecorder.cpp
index 966659901..5cdbab332 100644
--- a/tests/auto/unit/qmediarecorder/tst_qmediarecorder.cpp
+++ b/tests/auto/unit/qmediarecorder/tst_qmediarecorder.cpp
@@ -139,7 +139,7 @@ void tst_QMediaRecorder::testNullService()
 {
     const QString id(QLatin1String("application/x-format"));
 
-    MockMediaObject object(0, 0);
+    MockMediaObject object(nullptr, nullptr);
     QMediaRecorder recorder(&object);
 
     QCOMPARE(recorder.outputLocation(), QUrl());
@@ -171,9 +171,9 @@ void tst_QMediaRecorder::testNullControls()
 {
     const QString id(QLatin1String("application/x-format"));
 
-    MockMediaRecorderService service(0, 0);
+    MockMediaRecorderService service(nullptr, nullptr);
     service.hasControls = false;
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
     QMediaRecorder recorder(&object);
 
     QCOMPARE(recorder.outputLocation(), QUrl());
@@ -247,7 +247,7 @@ void tst_QMediaRecorder::testDeleteMediaObject()
     delete service;
     delete mock;
 
-    QVERIFY(capture->mediaObject() == 0);
+    QVERIFY(capture->mediaObject() == nullptr);
     QVERIFY(!capture->isAvailable());
 
     delete capture;
@@ -776,9 +776,9 @@ void tst_QMediaRecorder::testVideoSettings()
 
 void tst_QMediaRecorder::testSettingsApplied()
 {
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
-    MockMediaObject object(0, &service);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
+    MockMediaObject object(nullptr, &service);
 
     //if the media recorder is not configured after construction
     //the settings are applied in the next event loop
@@ -819,10 +819,10 @@ void tst_QMediaRecorder::nullMetaDataControl()
     const QString titleKey(QLatin1String("Title"));
     const QString title(QLatin1String("Host of Seraphim"));
 
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
     service.hasControls = false;
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
 
     QMediaRecorder recorder(&object);
 
@@ -840,10 +840,10 @@ void tst_QMediaRecorder::nullMetaDataControl()
 
 void tst_QMediaRecorder::isMetaDataAvailable()
 {
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
     service.mockMetaDataControl->setMetaDataAvailable(false);
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
 
     QMediaRecorder recorder(&object);
     QCOMPARE(recorder.isMetaDataAvailable(), false);
@@ -864,11 +864,11 @@ void tst_QMediaRecorder::isMetaDataAvailable()
 
 void tst_QMediaRecorder::isWritable()
 {
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
     service.mockMetaDataControl->setWritable(false);
 
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
 
     QMediaRecorder recorder(&object);
 
@@ -891,9 +891,9 @@ void tst_QMediaRecorder::isWritable()
 
 void tst_QMediaRecorder::metaDataChanged()
 {
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
-    MockMediaObject object(0, &service);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
+    MockMediaObject object(nullptr, &service);
 
     QMediaRecorder recorder(&object);
 
@@ -938,11 +938,11 @@ void tst_QMediaRecorder::metaData()
     QFETCH(QString, genre);
     QFETCH(QString, custom);
 
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
     service.mockMetaDataControl->populateMetaData();
 
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
 
     QMediaRecorder recorder(&object);
     QVERIFY(object.availableMetaData().isEmpty());
@@ -975,11 +975,11 @@ void tst_QMediaRecorder::setMetaData()
 {
     QFETCH(QString, title);
 
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service(0, &recorderControl);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service(nullptr, &recorderControl);
     service.mockMetaDataControl->populateMetaData();
 
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
 
     QMediaRecorder recorder(&object);
 
@@ -1126,26 +1126,26 @@ void tst_QMediaRecorder::testAudioSettingsDestructor()
 void tst_QMediaRecorder::testAvailabilityStatus()
 {
     {
-        MockMediaRecorderService service(0, 0);
-        MockMediaObject object(0, &service);
+        MockMediaRecorderService service(nullptr, nullptr);
+        MockMediaObject object(nullptr, &service);
         QMediaRecorder recorder(&object);
         QCOMPARE(recorder.availability(), QMultimedia::ServiceMissing);
         QCOMPARE(recorder.isAvailable(), false);
     }
     {
-        MockMediaRecorderControl recorderControl(0);
-        MockMediaRecorderService service1(0, &recorderControl);
+        MockMediaRecorderControl recorderControl(nullptr);
+        MockMediaRecorderService service1(nullptr, &recorderControl);
         service1.mockMetaDataControl->populateMetaData();
-        MockMediaObject object1(0, &service1);
+        MockMediaObject object1(nullptr, &service1);
         QMediaRecorder recorder1(&object1);
         QCOMPARE(recorder1.availability(), QMultimedia::Available);
         QCOMPARE(recorder1.isAvailable(), true);
     }
     {
-        MockMediaRecorderControl recorderControl(0);
-        MockMediaRecorderService service1(0, &recorderControl);
+        MockMediaRecorderControl recorderControl(nullptr);
+        MockMediaRecorderService service1(nullptr, &recorderControl);
         service1.mockMetaDataControl->populateMetaData();
-        MockMediaObject object1(0, &service1);
+        MockMediaObject object1(nullptr, &service1);
         QMediaRecorder recorder1(&object1);
 
         QCOMPARE(recorder1.availability(), QMultimedia::Available);
@@ -1156,15 +1156,15 @@ void tst_QMediaRecorder::testAvailabilityStatus()
 /* isAvailable() API test. */
 void tst_QMediaRecorder::testIsAvailable()
 {
-    MockMediaRecorderService service(0, 0);
-    MockMediaObject object(0, &service);
+    MockMediaRecorderService service(nullptr, nullptr);
+    MockMediaObject object(nullptr, &service);
     QMediaRecorder recorder(&object);
     QCOMPARE(recorder.isAvailable(), false);
 
-    MockMediaRecorderControl recorderControl(0);
-    MockMediaRecorderService service1(0, &recorderControl);
+    MockMediaRecorderControl recorderControl(nullptr);
+    MockMediaRecorderService service1(nullptr, &recorderControl);
     service1.mockMetaDataControl->populateMetaData();
-    MockMediaObject object1(0, &service1);
+    MockMediaObject object1(nullptr, &service1);
     QMediaRecorder recorder1(&object1);
     QCOMPARE(recorder1.isAvailable(), true);
 }
@@ -1172,16 +1172,16 @@ void tst_QMediaRecorder::testIsAvailable()
 /* mediaObject() API test. */
 void tst_QMediaRecorder::testMediaObject()
 {
-    MockMediaRecorderService service(0, 0);
+    MockMediaRecorderService service(nullptr, nullptr);
     service.hasControls = false;
-    MockMediaObject object(0, &service);
+    MockMediaObject object(nullptr, &service);
     QMediaRecorder recorder(&object);
 
     QMediaObject *medobj = recorder.mediaObject();
-    QVERIFY(medobj == NULL);
+    QVERIFY(medobj == nullptr);
 
     QMediaObject *medobj1 = capture->mediaObject();
-    QVERIFY(medobj1 != NULL);
+    QVERIFY(medobj1 != nullptr);
 }
 
 /* enum QMediaRecorder::ResourceError property test. */
@@ -1458,13 +1458,13 @@ void tst_QMediaRecorder::testVideoSettingsDestructor()
 {
     /* Create the instance on heap and verify if object deleted correctly*/
     QVideoEncoderSettings *settings1 = new QVideoEncoderSettings();
-    QVERIFY(settings1 != NULL);
+    QVERIFY(settings1 != nullptr);
     QVERIFY(settings1->isNull());
     delete settings1;
 
     /* Create the instance on heap and initialise it and verify if object deleted correctly.*/
     QVideoEncoderSettings *settings2 = new QVideoEncoderSettings();
-    QVERIFY(settings2 != NULL);
+    QVERIFY(settings2 != nullptr);
     settings2->setCodec(QString("codec"));
     QVERIFY(!settings2->isNull());
     delete settings2;
diff --git a/tests/auto/unit/qmediaservice/tst_qmediaservice.cpp b/tests/auto/unit/qmediaservice/tst_qmediaservice.cpp
index fcc3933f3..e20b0f8ec 100644
--- a/tests/auto/unit/qmediaservice/tst_qmediaservice.cpp
+++ b/tests/auto/unit/qmediaservice/tst_qmediaservice.cpp
@@ -85,20 +85,17 @@ class QtTestMediaService : public QMediaService
 {
     Q_OBJECT
 public:
-    int refA;
-    int refB;
-    int refC;
+    int refA = 0;
+    int refB = 0;
+    int refC = 0;
     QtTestMediaControlA controlA;
     QtTestMediaControlB controlB;
     QtTestMediaControlC controlC;
 
-    //constructor
-    QtTestMediaService(): QMediaService(0), refA(0), refB(0), refC(0)
-    {
-    }
+    QtTestMediaService() : QMediaService(nullptr) {}
 
     //requestControl() pure virtual function of QMediaService class.
-    QMediaControl *requestControl(const char *name)
+    QMediaControl *requestControl(const char *name) override
     {
         if (strcmp(name, QtTestMediaControlA_iid) == 0) {
             refA += 1;
@@ -113,12 +110,12 @@ public:
 
             return &controlA;
         } else {
-            return 0;
+            return nullptr;
         }
     }
 
     //releaseControl() pure virtual function of QMediaService class.
-    void releaseControl(QMediaControl *control)
+    void releaseControl(QMediaControl *control) override
     {
         if (control == &controlA)
             refA -= 1;
@@ -231,7 +228,7 @@ void tst_QMediaService::tst_requestControlTemplate()
 
 void tst_QMediaService::control_iid()
 {
-    const char *nullString = 0;
+    const char *nullString = nullptr;
 
     // Default implementation.
     QCOMPARE(qmediacontrol_iid<QtTestMediaControlE *>(), nullString);
diff --git a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin1/mockserviceplugin1.cpp b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin1/mockserviceplugin1.cpp
index 3b8946b92..e7fe82075 100644
--- a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin1/mockserviceplugin1.cpp
+++ b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin1/mockserviceplugin1.cpp
@@ -37,26 +37,26 @@ class MockServicePlugin1 : public QMediaServiceProviderPlugin,
     Q_INTERFACES(QMediaServiceSupportedFormatsInterface)
     Q_PLUGIN_METADATA(IID "org.qt-project.qt.mediaserviceproviderfactory/5.0" FILE "mockserviceplugin1.json")
 public:
-    QStringList keys() const
+    [[nodiscard]] QStringList keys() const
     {
         return QStringList() <<
                 QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER);
     }
 
-    QMediaService* create(QString const& key)
+    QMediaService* create(QString const& key) override
     {
         if (keys().contains(key))
             return new MockMediaService("MockServicePlugin1");
         else
-            return 0;
+            return nullptr;
     }
 
-    void release(QMediaService *service)
+    void release(QMediaService *service) override
     {
         delete service;
     }
 
-    QMultimedia::SupportEstimate hasSupport(const QString &mimeType, const QStringList& codecs) const
+    [[nodiscard]] QMultimedia::SupportEstimate hasSupport(const QString &mimeType, const QStringList& codecs) const override
     {
         if (codecs.contains(QLatin1String("mpeg4")))
             return QMultimedia::NotSupported;
@@ -68,7 +68,7 @@ public:
         return QMultimedia::MaybeSupported;
     }
 
-    QStringList supportedMimeTypes() const
+    [[nodiscard]] QStringList supportedMimeTypes() const override
     {
         return QStringList("audio/ogg");
     }
diff --git a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin2/mockserviceplugin2.cpp b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin2/mockserviceplugin2.cpp
index f0567e82d..221c02cf0 100644
--- a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin2/mockserviceplugin2.cpp
+++ b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin2/mockserviceplugin2.cpp
@@ -39,25 +39,25 @@ class MockServicePlugin2 : public QMediaServiceProviderPlugin,
     Q_INTERFACES(QMediaServiceFeaturesInterface)
     Q_PLUGIN_METADATA(IID "org.qt-project.qt.mediaserviceproviderfactory/5.0" FILE "mockserviceplugin2.json")
 public:
-    QStringList keys() const
+    [[nodiscard]] QStringList keys() const
     {
         return QStringList() << QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER);
     }
 
-    QMediaService* create(QString const& key)
+    QMediaService* create(QString const& key) override
     {
         if (keys().contains(key))
             return new MockMediaService("MockServicePlugin2");
         else
-            return 0;
+            return nullptr;
     }
 
-    void release(QMediaService *service)
+    void release(QMediaService *service) override
     {
         delete service;
     }
 
-    QMultimedia::SupportEstimate hasSupport(const QString &mimeType, const QStringList& codecs) const
+    [[nodiscard]] QMultimedia::SupportEstimate hasSupport(const QString &mimeType, const QStringList& codecs) const override
     {
         Q_UNUSED(codecs);
 
@@ -67,12 +67,12 @@ public:
         return QMultimedia::NotSupported;
     }
 
-    QStringList supportedMimeTypes() const
+    [[nodiscard]] QStringList supportedMimeTypes() const override
     {
         return QStringList("audio/wav");
     }
 
-    QMediaServiceFeaturesInterface::Features supportedFeatures(const QByteArray &service) const
+    [[nodiscard]] QMediaServiceFeaturesInterface::Features supportedFeatures(const QByteArray &service) const override
     {
         QMediaServiceFeaturesInterface::Features result;
         if (service == QByteArray(Q_MEDIASERVICE_MEDIAPLAYER))
diff --git a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin3/mockserviceplugin3.cpp b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin3/mockserviceplugin3.cpp
index dc59e2108..5b29c6327 100644
--- a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin3/mockserviceplugin3.cpp
+++ b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin3/mockserviceplugin3.cpp
@@ -37,7 +37,7 @@ class MockServicePlugin3 : public QMediaServiceProviderPlugin,
     Q_INTERFACES(QMediaServiceSupportedDevicesInterface)
     Q_PLUGIN_METADATA(IID "org.qt-project.qt.mediaserviceproviderfactory/5.0" FILE "mockserviceplugin3.json")
 public:
-    QStringList keys() const
+    [[nodiscard]] QStringList keys() const
     {
         return QStringList() <<
                QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER) <<
@@ -45,20 +45,20 @@ public:
                QLatin1String(Q_MEDIASERVICE_CAMERA);
     }
 
-    QMediaService* create(QString const& key)
+    QMediaService* create(QString const& key) override
     {
         if (keys().contains(key))
             return new MockMediaService("MockServicePlugin3");
         else
-            return 0;
+            return nullptr;
     }
 
-    void release(QMediaService *service)
+    void release(QMediaService *service) override
     {
         delete service;
     }
 
-    QByteArray defaultDevice(const QByteArray &service) const
+    [[nodiscard]] QByteArray defaultDevice(const QByteArray &service) const override
     {
         if (service == Q_MEDIASERVICE_AUDIOSOURCE)
             return "audiosource1";
@@ -69,7 +69,7 @@ public:
         return QByteArray();
     }
 
-    QList<QByteArray> devices(const QByteArray &service) const
+    [[nodiscard]] QList<QByteArray> devices(const QByteArray &service) const override
     {
         QList<QByteArray> res;
         if (service == Q_MEDIASERVICE_AUDIOSOURCE)
@@ -81,7 +81,7 @@ public:
         return res;
     }
 
-    QString deviceDescription(const QByteArray &service, const QByteArray &device)
+    QString deviceDescription(const QByteArray &service, const QByteArray &device) override
     {
         if (devices(service).contains(device))
             return QString(device)+" description";
diff --git a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin4/mockserviceplugin4.cpp b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin4/mockserviceplugin4.cpp
index f7d3c526e..b4b08993f 100644
--- a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin4/mockserviceplugin4.cpp
+++ b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin4/mockserviceplugin4.cpp
@@ -39,25 +39,25 @@ class MockServicePlugin4 : public QMediaServiceProviderPlugin,
     Q_INTERFACES(QMediaServiceFeaturesInterface)
     Q_PLUGIN_METADATA(IID "org.qt-project.qt.mediaserviceproviderfactory/5.0" FILE "mockserviceplugin4.json")
 public:
-    QStringList keys() const
+    [[nodiscard]] QStringList keys() const
     {
         return QStringList() << QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER);
     }
 
-    QMediaService* create(QString const& key)
+    QMediaService* create(QString const& key) override
     {
         if (keys().contains(key))
             return new MockMediaService("MockServicePlugin4");
         else
-            return 0;
+            return nullptr;
     }
 
-    void release(QMediaService *service)
+    void release(QMediaService *service) override
     {
         delete service;
     }
 
-    QMultimedia::SupportEstimate hasSupport(const QString &mimeType, const QStringList& codecs) const
+    [[nodiscard]] QMultimedia::SupportEstimate hasSupport(const QString &mimeType, const QStringList& codecs) const override
     {
         if (codecs.contains(QLatin1String("jpeg2000")))
             return QMultimedia::NotSupported;
@@ -68,12 +68,12 @@ public:
         return QMultimedia::MaybeSupported;
     }
 
-    QStringList supportedMimeTypes() const
+    [[nodiscard]] QStringList supportedMimeTypes() const override
     {
         return QStringList() << "video/mp4" << "video/quicktime";
     }
 
-    QMediaServiceFeaturesInterface::Features supportedFeatures(const QByteArray &service) const
+    [[nodiscard]] QMediaServiceFeaturesInterface::Features supportedFeatures(const QByteArray &service) const override
     {
         QMediaServiceFeaturesInterface::Features result;
         if (service == QByteArray(Q_MEDIASERVICE_MEDIAPLAYER))
diff --git a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin5/mockserviceplugin5.cpp b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin5/mockserviceplugin5.cpp
index a94a3c631..7a28b098a 100644
--- a/tests/auto/unit/qmediaserviceprovider/mockserviceplugin5/mockserviceplugin5.cpp
+++ b/tests/auto/unit/qmediaserviceprovider/mockserviceplugin5/mockserviceplugin5.cpp
@@ -37,25 +37,25 @@ class MockServicePlugin5 : public QMediaServiceProviderPlugin,
     Q_INTERFACES(QMediaServiceSupportedDevicesInterface)
     Q_PLUGIN_METADATA(IID "org.qt-project.qt.mediaserviceproviderfactory/5.0" FILE "mockserviceplugin5.json")
 public:
-    QStringList keys() const
+    [[nodiscard]] QStringList keys() const
     {
         return QStringList() << QLatin1String(Q_MEDIASERVICE_CAMERA);
     }
 
-    QMediaService* create(QString const& key)
+    QMediaService* create(QString const& key) override
     {
         if (keys().contains(key))
             return new MockMediaService("MockServicePlugin5");
         else
-            return 0;
+            return nullptr;
     }
 
-    void release(QMediaService *service)
+    void release(QMediaService *service) override
     {
         delete service;
     }
 
-    QByteArray defaultDevice(const QByteArray &service) const
+    [[nodiscard]] QByteArray defaultDevice(const QByteArray &service) const override
     {
         if (service == Q_MEDIASERVICE_CAMERA)
             return "backcamera";
@@ -63,7 +63,7 @@ public:
         return QByteArray();
     }
 
-    QList<QByteArray> devices(const QByteArray &service) const
+    [[nodiscard]] QList<QByteArray> devices(const QByteArray &service) const override
     {
         QList<QByteArray> res;
         if (service == Q_MEDIASERVICE_CAMERA)
@@ -72,7 +72,7 @@ public:
         return res;
     }
 
-    QString deviceDescription(const QByteArray &service, const QByteArray &device)
+    QString deviceDescription(const QByteArray &service, const QByteArray &device) override
     {
         if (devices(service).contains(device))
             return QString(device)+" description";
diff --git a/tests/auto/unit/qmediaserviceprovider/tst_qmediaserviceprovider.cpp b/tests/auto/unit/qmediaserviceprovider/tst_qmediaserviceprovider.cpp
index 673af9992..074ead67d 100644
--- a/tests/auto/unit/qmediaserviceprovider/tst_qmediaserviceprovider.cpp
+++ b/tests/auto/unit/qmediaserviceprovider/tst_qmediaserviceprovider.cpp
@@ -45,13 +45,13 @@ QT_USE_NAMESPACE
 
 class MockMediaServiceProvider : public QMediaServiceProvider
 {
-    QMediaService* requestService(const QByteArray &type)
+    QMediaService* requestService(const QByteArray &type) override
     {
         Q_UNUSED(type);
-        return 0;
+        return nullptr;
     }
 
-    void releaseService(QMediaService *service)
+    void releaseService(QMediaService *service) override
     {
         Q_UNUSED(service);
     }
@@ -89,21 +89,21 @@ void tst_QMediaServiceProvider::initTestCase()
 void tst_QMediaServiceProvider::testDefaultProviderAvailable()
 {
     // Must always be a default provider available
-    QVERIFY(QMediaServiceProvider::defaultServiceProvider() != 0);
+    QVERIFY(QMediaServiceProvider::defaultServiceProvider() != nullptr);
 }
 
 void tst_QMediaServiceProvider::testObtainService()
 {
     QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
 
-    if (provider == 0)
+    if (provider == nullptr)
         QSKIP("No default provider");
 
-    QMediaService *service = 0;
+    QMediaService *service = nullptr;
 
     // Player
     service = provider->requestService(Q_MEDIASERVICE_MEDIAPLAYER);
-    QVERIFY(service != 0);
+    QVERIFY(service != nullptr);
     provider->releaseService(service);
 }
 
@@ -115,7 +115,7 @@ void tst_QMediaServiceProvider::testHasSupport()
 
     QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
 
-    if (provider == 0)
+    if (provider == nullptr)
         QSKIP("No default provider");
 
     QCOMPARE(provider->hasSupport(QByteArray(Q_MEDIASERVICE_MEDIAPLAYER), "video/ogv", QStringList()),
@@ -159,13 +159,13 @@ void tst_QMediaServiceProvider::testHasSupport()
              QMultimedia::MaybeSupported);
 
     //ensure the correct media player plugin is chosen for mime type
-    QMediaPlayer simplePlayer(0, QMediaPlayer::LowLatency);
+    QMediaPlayer simplePlayer(nullptr, QMediaPlayer::LowLatency);
     QCOMPARE(simplePlayer.service()->objectName(), QLatin1String("MockServicePlugin2"));
 
     QMediaPlayer mediaPlayer;
     QVERIFY(mediaPlayer.service()->objectName() != QLatin1String("MockServicePlugin2"));
 
-    QMediaPlayer streamPlayer(0, QMediaPlayer::StreamPlayback);
+    QMediaPlayer streamPlayer(nullptr, QMediaPlayer::StreamPlayback);
     QCOMPARE(streamPlayer.service()->objectName(), QLatin1String("MockServicePlugin4"));
 }
 
@@ -173,7 +173,7 @@ void tst_QMediaServiceProvider::testSupportedMimeTypes()
 {
     QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
 
-    if (provider == 0)
+    if (provider == nullptr)
         QSKIP("No default provider");
 
     QVERIFY(provider->supportedMimeTypes(QByteArray(Q_MEDIASERVICE_MEDIAPLAYER)).contains("audio/ogg"));
@@ -184,7 +184,7 @@ void tst_QMediaServiceProvider::testDefaultDevice()
 {
     QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
 
-    if (provider == 0)
+    if (provider == nullptr)
         QSKIP("No default provider");
 
     QCOMPARE(provider->defaultDevice(Q_MEDIASERVICE_AUDIOSOURCE), QByteArray("audiosource1"));
@@ -195,7 +195,7 @@ void tst_QMediaServiceProvider::testAvailableDevices()
 {
     QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
 
-    if (provider == 0)
+    if (provider == nullptr)
         QSKIP("No default provider");
 
     QList<QByteArray> devices = provider->devices(Q_MEDIASERVICE_AUDIOSOURCE);
@@ -214,7 +214,7 @@ void tst_QMediaServiceProvider::testCameraInfo()
 {
     QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
 
-    if (provider == 0)
+    if (provider == nullptr)
         QSKIP("No default provider");
 
     QCOMPARE(provider->cameraPosition("backcamera"), QCamera::BackFace);
diff --git a/tests/auto/unit/qmetadatareadercontrol/tst_qmetadatareadercontrol.cpp b/tests/auto/unit/qmetadatareadercontrol/tst_qmetadatareadercontrol.cpp
index 381c34407..3e14dc3c7 100644
--- a/tests/auto/unit/qmetadatareadercontrol/tst_qmetadatareadercontrol.cpp
+++ b/tests/auto/unit/qmetadatareadercontrol/tst_qmetadatareadercontrol.cpp
@@ -52,7 +52,7 @@ QTEST_MAIN(tst_QMetaDataReaderControl);
 void tst_QMetaDataReaderControl::metaDataReaderControlConstructor()
 {
     MockMetaDataReaderControl *metaData = new MockMetaDataReaderControl();
-    QVERIFY(metaData !=NULL);
+    QVERIFY(metaData !=nullptr);
     delete metaData;
 }
 
@@ -60,7 +60,7 @@ void tst_QMetaDataReaderControl::metaDataReaderControlConstructor()
 void tst_QMetaDataReaderControl::metaDataReaderControlAvailableMetaData()
 {
     MockMetaDataReaderControl *metaData = new MockMetaDataReaderControl();
-    QVERIFY(metaData !=NULL);
+    QVERIFY(metaData !=nullptr);
     metaData->availableMetaData() ;
     delete metaData;
 }
@@ -69,7 +69,7 @@ void tst_QMetaDataReaderControl::metaDataReaderControlAvailableMetaData()
 void tst_QMetaDataReaderControl::metaDataReaderControlIsMetaDataAvailable ()
 {
     MockMetaDataReaderControl *metaData = new MockMetaDataReaderControl();
-    QVERIFY(metaData !=NULL);
+    QVERIFY(metaData !=nullptr);
     metaData->availableMetaData();
     delete metaData;
 }
@@ -78,7 +78,7 @@ void tst_QMetaDataReaderControl::metaDataReaderControlIsMetaDataAvailable ()
 void tst_QMetaDataReaderControl::metaDataReaderControlMetaData ()
 {
     MockMetaDataReaderControl *metaData = new MockMetaDataReaderControl();
-    QVERIFY(metaData !=NULL);
+    QVERIFY(metaData !=nullptr);
     metaData->metaData(QMediaMetaData::Title);
     delete metaData;
 }
@@ -87,7 +87,7 @@ void tst_QMetaDataReaderControl::metaDataReaderControlMetaData ()
 void tst_QMetaDataReaderControl::metaDataReaderControlMetaDataAvailableChangedSignal ()
 {
     MockMetaDataReaderControl *metaData = new MockMetaDataReaderControl();
-    QVERIFY(metaData !=NULL);
+    QVERIFY(metaData !=nullptr);
     QSignalSpy spy(metaData,SIGNAL(metaDataAvailableChanged(bool)));
     metaData->setMetaDataAvailable(true);
     QVERIFY(spy.count() == 1);
@@ -98,7 +98,7 @@ void tst_QMetaDataReaderControl::metaDataReaderControlMetaDataAvailableChangedSi
 void tst_QMetaDataReaderControl::metaDataReaderControlMetaDataChangedSignal ()
 {
     MockMetaDataReaderControl *metaData = new MockMetaDataReaderControl();
-    QVERIFY(metaData !=NULL);
+    QVERIFY(metaData !=nullptr);
     QSignalSpy spy(metaData,SIGNAL(metaDataChanged()));
     metaData->metaDataChanged();
     QVERIFY(spy.count () == 1);
diff --git a/tests/auto/unit/qpaintervideosurface/tst_qpaintervideosurface.cpp b/tests/auto/unit/qpaintervideosurface/tst_qpaintervideosurface.cpp
index be5c85ab9..aea3e0e61 100644
--- a/tests/auto/unit/qpaintervideosurface/tst_qpaintervideosurface.cpp
+++ b/tests/auto/unit/qpaintervideosurface/tst_qpaintervideosurface.cpp
@@ -88,26 +88,25 @@ class QtTestGLVideoBuffer : public QAbstractVideoBuffer
 public:
     QtTestGLVideoBuffer()
         : QAbstractVideoBuffer(GLTextureHandle)
-        , m_textureId(0)
     {
         QOpenGLContext::currentContext()->functions()->glGenTextures(1, &m_textureId);
     }
 
-    ~QtTestGLVideoBuffer()
+    ~QtTestGLVideoBuffer() override
     {
         QOpenGLContext::currentContext()->functions()->glDeleteTextures(1, &m_textureId);
     }
 
-    GLuint textureId() const { return m_textureId; }
+    [[nodiscard]] GLuint textureId() const { return m_textureId; }
 
-    QVariant handle() const { return m_textureId; }
+    [[nodiscard]] QVariant handle() const override { return m_textureId; }
 
-    uchar *map(MapMode, int *, int *) { return 0; }
-    void unmap() {}
-    MapMode mapMode() const { return NotMapped; }
+    uchar *map(MapMode, int *, int *) override { return nullptr; }
+    void unmap() override {}
+    [[nodiscard]] MapMode mapMode() const override { return NotMapped; }
 
 private:
-    GLuint m_textureId;
+    GLuint m_textureId = 0;
 };
 
 #endif
@@ -119,9 +118,9 @@ public:
         : QAbstractVideoBuffer(UserHandle)
     {}
 
-    uchar *map(MapMode, int *, int *) { return 0; }
-    void unmap() {}
-    MapMode mapMode() const { return NotMapped; }
+    uchar *map(MapMode, int *, int *) override { return nullptr; }
+    void unmap() override {}
+    [[nodiscard]] MapMode mapMode() const override { return NotMapped; }
 };
 
 void tst_QPainterVideoSurface::colors()
diff --git a/tests/auto/unit/qvideoencodersettingscontrol/tst_qvideoencodersettingscontrol.cpp b/tests/auto/unit/qvideoencodersettingscontrol/tst_qvideoencodersettingscontrol.cpp
index 47da7be19..03fd1d990 100644
--- a/tests/auto/unit/qvideoencodersettingscontrol/tst_qvideoencodersettingscontrol.cpp
+++ b/tests/auto/unit/qvideoencodersettingscontrol/tst_qvideoencodersettingscontrol.cpp
@@ -35,17 +35,17 @@ class MyVideEncoderControl: public QVideoEncoderSettingsControl
     Q_OBJECT
 
 public:
-    MyVideEncoderControl(QObject *parent = 0 ):QVideoEncoderSettingsControl(parent)
+    MyVideEncoderControl(QObject *parent = nullptr ):QVideoEncoderSettingsControl(parent)
     {
 
     }
 
-    ~MyVideEncoderControl()
+    ~MyVideEncoderControl() override
     {
 
     }
 
-    QList<QSize> supportedResolutions(const QVideoEncoderSettings &settings,bool *continuous = 0) const
+    QList<QSize> supportedResolutions(const QVideoEncoderSettings &settings,bool *continuous = nullptr) const override
     {
         Q_UNUSED(settings);
         Q_UNUSED(continuous);
@@ -53,7 +53,7 @@ public:
         return (QList<QSize>());
     }
 
-    QList<qreal> supportedFrameRates(const QVideoEncoderSettings &settings, bool *continuous = 0) const
+    QList<qreal> supportedFrameRates(const QVideoEncoderSettings &settings, bool *continuous = nullptr) const override
     {
         Q_UNUSED(settings);
         Q_UNUSED(continuous);
@@ -62,25 +62,25 @@ public:
 
     }
 
-    QStringList supportedVideoCodecs() const
+    [[nodiscard]] QStringList supportedVideoCodecs() const override
     {
         return QStringList();
 
     }
 
-    QString videoCodecDescription(const QString &codecName) const
+    [[nodiscard]] QString videoCodecDescription(const QString &codecName) const override
     {
         Q_UNUSED(codecName);
         return QString();
 
     }
 
-    QVideoEncoderSettings videoSettings() const
+    [[nodiscard]] QVideoEncoderSettings videoSettings() const override
     {
         return QVideoEncoderSettings();
     }
 
-    void setVideoSettings(const QVideoEncoderSettings &settings)
+    void setVideoSettings(const QVideoEncoderSettings &settings) override
     {
         Q_UNUSED(settings);
     }
diff --git a/tests/auto/unit/qvideoframe/tst_qvideoframe.cpp b/tests/auto/unit/qvideoframe/tst_qvideoframe.cpp
index 3e65fbba9..89dd297b8 100644
--- a/tests/auto/unit/qvideoframe/tst_qvideoframe.cpp
+++ b/tests/auto/unit/qvideoframe/tst_qvideoframe.cpp
@@ -48,7 +48,7 @@ class tst_QVideoFrame : public QObject
     Q_OBJECT
 public:
     tst_QVideoFrame();
-    ~tst_QVideoFrame();
+    ~tst_QVideoFrame() override;
 
 public slots:
     void initTestCase();
@@ -105,23 +105,25 @@ public:
     explicit QtTestVideoBuffer(QAbstractVideoBuffer::HandleType type)
         : QAbstractVideoBuffer(type) {}
 
-    MapMode mapMode() const { return NotMapped; }
+    [[nodiscard]] MapMode mapMode() const override { return NotMapped; }
 
-    uchar *map(MapMode, int *, int *) { return 0; }
-    void unmap() {}
+    uchar *map(MapMode, int *, int *) override { return nullptr; }
+    void unmap() override {}
 };
 
 class QtTestPlanarVideoBuffer : public QAbstractPlanarVideoBuffer
 {
 public:
     QtTestPlanarVideoBuffer()
-        : QAbstractPlanarVideoBuffer(NoHandle), m_planeCount(0), m_mapMode(NotMapped) {}
+        : QAbstractPlanarVideoBuffer(NoHandle)
+    {}
     explicit QtTestPlanarVideoBuffer(QAbstractVideoBuffer::HandleType type)
-        : QAbstractPlanarVideoBuffer(type), m_planeCount(0), m_mapMode(NotMapped) {}
+        : QAbstractPlanarVideoBuffer(type)
+    {}
 
-    MapMode mapMode() const { return m_mapMode; }
+    [[nodiscard]] MapMode mapMode() const override { return m_mapMode; }
 
-    int map(MapMode mode, int *numBytes, int bytesPerLine[4], uchar *data[4]) {
+    int map(MapMode mode, int *numBytes, int bytesPerLine[4], uchar *data[4]) override {
         m_mapMode = mode;
         if (numBytes)
             *numBytes = m_numBytes;
@@ -131,13 +133,13 @@ public:
         }
         return m_planeCount;
     }
-    void unmap() { m_mapMode = NotMapped; }
+    void unmap() override { m_mapMode = NotMapped; }
 
     uchar *m_data[4];
     int m_bytesPerLine[4];
-    int m_planeCount;
+    int m_planeCount = 0;
     int m_numBytes;
-    MapMode m_mapMode;
+    MapMode m_mapMode = NotMapped;
 };
 
 tst_QVideoFrame::tst_QVideoFrame()
@@ -368,7 +370,7 @@ void tst_QVideoFrame::createNull()
 
     // Null buffer (shouldn't crash)
     {
-        QVideoFrame frame(0, QSize(1024,768), QVideoFrame::Format_ARGB32);
+        QVideoFrame frame(nullptr, QSize(1024,768), QVideoFrame::Format_ARGB32);
         QVERIFY(!frame.isValid());
         QCOMPARE(frame.handleType(), QAbstractVideoBuffer::NoHandle);
         QCOMPARE(frame.pixelFormat(), QVideoFrame::Format_ARGB32);
diff --git a/tests/auto/unit/qvideoprobe/tst_qvideoprobe.cpp b/tests/auto/unit/qvideoprobe/tst_qvideoprobe.cpp
index a53742469..26d6ed0ad 100644
--- a/tests/auto/unit/qvideoprobe/tst_qvideoprobe.cpp
+++ b/tests/auto/unit/qvideoprobe/tst_qvideoprobe.cpp
@@ -72,7 +72,7 @@ void tst_QVideoProbe::init()
     mockMediaPlayerService = new MockMediaPlayerService();
     mockProvider = new MockMediaServiceProvider(mockMediaPlayerService);
     mockProvider->deleteServiceOnRelease = true;
-    player = 0;
+    player = nullptr;
 
     mockMediaRecorderControl = new MockMediaRecorderControl(this);
     mockMediaRecorderService = new MockMediaRecorderService(this, mockMediaRecorderControl);
@@ -86,20 +86,20 @@ void tst_QVideoProbe::cleanup()
 {
     delete player;
     delete mockProvider;
-    mockMediaPlayerService = 0;
-    mockProvider = 0;
-    player = 0;
+    mockMediaPlayerService = nullptr;
+    mockProvider = nullptr;
+    player = nullptr;
 
     delete mockMediaRecorderControl;
     delete mockProviderRecorder;
-    mockMediaRecorderControl = 0;
-    mockMediaRecorderService = 0;
-    mockProviderRecorder = 0;
+    mockMediaRecorderControl = nullptr;
+    mockMediaRecorderService = nullptr;
+    mockProviderRecorder = nullptr;
 }
 
 void tst_QVideoProbe::testNullService()
 {
-    mockProvider->service = 0;
+    mockProvider->service = nullptr;
     player = new QMediaPlayer;
 
     QVERIFY(!player->isAvailable());
@@ -110,7 +110,7 @@ void tst_QVideoProbe::testNullService()
     QVERIFY(!probe.setSource(player));
     QVERIFY(!probe.isActive());
     delete player;
-    player = 0;
+    player = nullptr;
     QVERIFY(!probe.isActive());
 }
 
@@ -123,7 +123,7 @@ void tst_QVideoProbe::testPlayer()
     QVERIFY(!probe.isActive());
     QVERIFY(probe.setSource(player));
     QVERIFY(probe.isActive());
-    probe.setSource((QMediaPlayer*)0);
+    probe.setSource((QMediaPlayer*)nullptr);
     QVERIFY(!probe.isActive());
 }
 
@@ -138,9 +138,9 @@ void tst_QVideoProbe::testPlayerDeleteRecorder()
     QVERIFY(probe.isActive());
 
     delete player;
-    player = 0;
+    player = nullptr;
     QVERIFY(!probe.isActive());
-    probe.setSource((QMediaPlayer*)0);
+    probe.setSource((QMediaPlayer*)nullptr);
     QVERIFY(!probe.isActive());
 }
 
diff --git a/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp b/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp
index 4fa754a45..e3a9b3822 100644
--- a/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp
+++ b/tests/auto/unit/qvideosurfaceformat/tst_qvideosurfaceformat.cpp
@@ -43,7 +43,7 @@ class tst_QVideoSurfaceFormat : public QObject
     Q_OBJECT
 public:
     tst_QVideoSurfaceFormat();
-    ~tst_QVideoSurfaceFormat();
+    ~tst_QVideoSurfaceFormat() override;
 
 public slots:
     void initTestCase();
diff --git a/tests/auto/unit/qvideowidget/tst_qvideowidget.cpp b/tests/auto/unit/qvideowidget/tst_qvideowidget.cpp
index bcc4acb3a..41d681352 100644
--- a/tests/auto/unit/qvideowidget/tst_qvideowidget.cpp
+++ b/tests/auto/unit/qvideowidget/tst_qvideowidget.cpp
@@ -113,7 +113,7 @@ Q_DECLARE_METATYPE(const uchar *)
 class QtTestVideoWidget : public QVideoWidget
 {
 public:
-    QtTestVideoWidget(QWidget *parent = 0)
+    QtTestVideoWidget(QWidget *parent = nullptr)
         : QVideoWidget(parent)
     {
         setWindowFlags(Qt::X11BypassWindowManagerHint);
@@ -124,127 +124,101 @@ public:
 class QtTestWindowControl : public QVideoWindowControl
 {
 public:
-    QtTestWindowControl()
-        : m_winId(0)
-        , m_repaintCount(0)
-        , m_brightness(0)
-        , m_contrast(0)
-        , m_saturation(0)
-        , m_aspectRatioMode(Qt::KeepAspectRatio)
-        , m_fullScreen(0)
-    {
-    }
-
-    WId winId() const { return m_winId; }
-    void setWinId(WId id) { m_winId = id; }
+    [[nodiscard]] WId winId() const override { return m_winId; }
+    void setWinId(WId id) override { m_winId = id; }
 
-    QRect displayRect() const { return m_displayRect; }
-    void setDisplayRect(const QRect &rect) { m_displayRect = rect; }
+    [[nodiscard]] QRect displayRect() const override { return m_displayRect; }
+    void setDisplayRect(const QRect &rect) override { m_displayRect = rect; }
 
-    bool isFullScreen() const { return m_fullScreen; }
-    void setFullScreen(bool fullScreen) { emit fullScreenChanged(m_fullScreen = fullScreen); }
+    [[nodiscard]] bool isFullScreen() const override { return m_fullScreen; }
+    void setFullScreen(bool fullScreen) override { emit fullScreenChanged(m_fullScreen = fullScreen); }
 
-    int repaintCount() const { return m_repaintCount; }
+    [[nodiscard]] int repaintCount() const { return m_repaintCount; }
     void setRepaintCount(int count) { m_repaintCount = count; }
-    void repaint() { ++m_repaintCount; }
+    void repaint() override { ++m_repaintCount; }
 
-    QSize nativeSize() const { return m_nativeSize; }
+    [[nodiscard]] QSize nativeSize() const override { return m_nativeSize; }
     void setNativeSize(const QSize &size) { m_nativeSize = size; emit nativeSizeChanged(); }
 
-    Qt::AspectRatioMode aspectRatioMode() const { return m_aspectRatioMode; }
-    void setAspectRatioMode(Qt::AspectRatioMode mode) { m_aspectRatioMode = mode; }
+    [[nodiscard]] Qt::AspectRatioMode aspectRatioMode() const override { return m_aspectRatioMode; }
+    void setAspectRatioMode(Qt::AspectRatioMode mode) override { m_aspectRatioMode = mode; }
 
-    int brightness() const { return m_brightness; }
-    void setBrightness(int brightness) { emit brightnessChanged(m_brightness = brightness); }
+    [[nodiscard]] int brightness() const override { return m_brightness; }
+    void setBrightness(int brightness) override { emit brightnessChanged(m_brightness = brightness); }
 
-    int contrast() const { return m_contrast; }
-    void setContrast(int contrast) { emit contrastChanged(m_contrast = contrast); }
+    [[nodiscard]] int contrast() const override { return m_contrast; }
+    void setContrast(int contrast) override { emit contrastChanged(m_contrast = contrast); }
 
-    int hue() const { return m_hue; }
-    void setHue(int hue) { emit hueChanged(m_hue = hue); }
+    [[nodiscard]] int hue() const override { return m_hue; }
+    void setHue(int hue) override { emit hueChanged(m_hue = hue); }
 
-    int saturation() const { return m_saturation; }
-    void setSaturation(int saturation) { emit saturationChanged(m_saturation = saturation); }
+    [[nodiscard]] int saturation() const override { return m_saturation; }
+    void setSaturation(int saturation) override { emit saturationChanged(m_saturation = saturation); }
 
 private:
-    WId m_winId;
-    int m_repaintCount;
-    int m_brightness;
-    int m_contrast;
+    WId m_winId = 0;
+    int m_repaintCount = 0;
+    int m_brightness = 0;
+    int m_contrast = 0;
     int m_hue;
-    int m_saturation;
-    Qt::AspectRatioMode m_aspectRatioMode;
+    int m_saturation = 0;
+    Qt::AspectRatioMode m_aspectRatioMode = Qt::KeepAspectRatio;
     QRect m_displayRect;
     QSize m_nativeSize;
-    bool m_fullScreen;
+    bool m_fullScreen = 0;
 };
 
 class QtTestWidgetControl : public QVideoWidgetControl
 {
 public:
-    QtTestWidgetControl()
-        : m_brightness(1.0)
-        , m_contrast(1.0)
-        , m_hue(1.0)
-        , m_saturation(1.0)
-        , m_aspectRatioMode(Qt::KeepAspectRatio)
-        , m_fullScreen(false)
-    {
-    }
+    [[nodiscard]] bool isFullScreen() const override { return m_fullScreen; }
+    void setFullScreen(bool fullScreen) override { emit fullScreenChanged(m_fullScreen = fullScreen); }
 
-    bool isFullScreen() const { return m_fullScreen; }
-    void setFullScreen(bool fullScreen) { emit fullScreenChanged(m_fullScreen = fullScreen); }
+    [[nodiscard]] Qt::AspectRatioMode aspectRatioMode() const override { return m_aspectRatioMode; }
+    void setAspectRatioMode(Qt::AspectRatioMode mode) override { m_aspectRatioMode = mode; }
 
-    Qt::AspectRatioMode aspectRatioMode() const { return m_aspectRatioMode; }
-    void setAspectRatioMode(Qt::AspectRatioMode mode) { m_aspectRatioMode = mode; }
+    [[nodiscard]] int brightness() const override { return m_brightness; }
+    void setBrightness(int brightness) override { emit brightnessChanged(m_brightness = brightness); }
 
-    int brightness() const { return m_brightness; }
-    void setBrightness(int brightness) { emit brightnessChanged(m_brightness = brightness); }
+    [[nodiscard]] int contrast() const override { return m_contrast; }
+    void setContrast(int contrast) override { emit contrastChanged(m_contrast = contrast); }
 
-    int contrast() const { return m_contrast; }
-    void setContrast(int contrast) { emit contrastChanged(m_contrast = contrast); }
+    [[nodiscard]] int hue() const override { return m_hue; }
+    void setHue(int hue) override { emit hueChanged(m_hue = hue); }
 
-    int hue() const { return m_hue; }
-    void setHue(int hue) { emit hueChanged(m_hue = hue); }
-
-    int saturation() const { return m_saturation; }
-    void setSaturation(int saturation) { emit saturationChanged(m_saturation = saturation); }
+    [[nodiscard]] int saturation() const override { return m_saturation; }
+    void setSaturation(int saturation) override { emit saturationChanged(m_saturation = saturation); }
 
     void setSizeHint(const QSize &size) { m_widget.setSizeHint(size); }
 
-    QWidget *videoWidget() { return &m_widget; }
+    QWidget *videoWidget() override { return &m_widget; }
 
 private:
     class Widget : public QWidget
     {
     public:
-        QSize sizeHint() const { return m_sizeHint; }
+        [[nodiscard]] QSize sizeHint() const override { return m_sizeHint; }
         void setSizeHint(const QSize &size) { m_sizeHint = size; updateGeometry(); }
     private:
         QSize m_sizeHint;
     } m_widget;
-    int m_brightness;
-    int m_contrast;
-    int m_hue;
-    int m_saturation;
-    Qt::AspectRatioMode m_aspectRatioMode;
+    int m_brightness = 1.0;
+    int m_contrast = 1.0;
+    int m_hue = 1.0;
+    int m_saturation = 1.0;
+    Qt::AspectRatioMode m_aspectRatioMode = Qt::KeepAspectRatio;
     QSize m_sizeHint;
-    bool m_fullScreen;
+    bool m_fullScreen = false;
 };
 
 class QtTestRendererControl : public QVideoRendererControl
 {
 public:
-    QtTestRendererControl()
-        : m_surface(0)
-    {
-    }
-
-    QAbstractVideoSurface *surface() const { return m_surface; }
-    void setSurface(QAbstractVideoSurface *surface) { m_surface = surface; }
+    [[nodiscard]] QAbstractVideoSurface *surface() const override { return m_surface; }
+    void setSurface(QAbstractVideoSurface *surface) override { m_surface = surface; }
 
 private:
-    QAbstractVideoSurface *m_surface;
+    QAbstractVideoSurface *m_surface = nullptr;
 };
 
 class QtTestVideoService : public QMediaService
@@ -255,7 +229,7 @@ public:
             QtTestWindowControl *window,
             QtTestWidgetControl *widget,
             QtTestRendererControl *renderer)
-        : QMediaService(0)
+        : QMediaService(nullptr)
         , windowRef(0)
         , widgetRef(0)
         , rendererRef(0)
@@ -265,14 +239,14 @@ public:
     {
     }
 
-    ~QtTestVideoService()
+    ~QtTestVideoService() override
     {
         delete windowControl;
         delete widgetControl;
         delete rendererControl;
     }
 
-    QMediaControl *requestControl(const char *name)
+    QMediaControl *requestControl(const char *name) override
     {
         if (qstrcmp(name, QVideoWindowControl_iid) == 0) {
             if (windowControl) {
@@ -293,10 +267,10 @@ public:
                 return rendererControl;
             }
         }
-        return 0;
+        return nullptr;
     }
 
-    void releaseControl(QMediaControl *control)
+    void releaseControl(QMediaControl *control) override
     {
         Q_ASSERT(control);
 
@@ -325,18 +299,18 @@ public:
             QtTestWindowControl *window,
             QtTestWidgetControl *widget,
             QtTestRendererControl *renderer):
-        QMediaObject(0, new QtTestVideoService(window, widget, renderer))
+        QMediaObject(nullptr, new QtTestVideoService(window, widget, renderer))
     {
         testService = qobject_cast<QtTestVideoService*>(service());
     }
 
     QtTestVideoObject(QtTestVideoService *service):
-        QMediaObject(0, service),
+        QMediaObject(nullptr, service),
         testService(service)
     {
     }
 
-    ~QtTestVideoObject()
+    ~QtTestVideoObject() override
     {
         delete testService;
     }
@@ -429,7 +403,7 @@ void tst_QVideoWidget::nullObject()
 
 void tst_QVideoWidget::nullService()
 {
-    QtTestVideoObject object(0);
+    QtTestVideoObject object(nullptr);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -461,7 +435,7 @@ void tst_QVideoWidget::nullService()
 
 void tst_QVideoWidget::noOutputs()
 {
-    QtTestVideoObject object(0, 0, 0);
+    QtTestVideoObject object(nullptr, nullptr, nullptr);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -490,7 +464,7 @@ void tst_QVideoWidget::serviceDestroyed()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(new QtTestWindowControl, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(new QtTestWindowControl, new QtTestWidgetControl, nullptr);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -504,7 +478,7 @@ void tst_QVideoWidget::serviceDestroyed()
     widget.setSaturation(100);
 
     delete object.testService;
-    object.testService = 0;
+    object.testService = nullptr;
 
     QCOMPARE(widget.mediaObject(), static_cast<QMediaObject *>(&object));
 
@@ -526,7 +500,7 @@ void tst_QVideoWidget::objectDestroyed()
     QtTestVideoObject *object = new QtTestVideoObject(
             new QtTestWindowControl,
             new QtTestWidgetControl,
-            0);
+            nullptr);
 
     QtTestVideoWidget widget;
     object->bind(&widget);
@@ -544,10 +518,10 @@ void tst_QVideoWidget::objectDestroyed()
 
     // Delete the media object without deleting the service.
     QtTestVideoService *service = object->testService;
-    object->testService = 0;
+    object->testService = nullptr;
 
     delete object;
-    object = 0;
+    object = nullptr;
 
     QCOMPARE(widget.mediaObject(), static_cast<QMediaObject *>(object));
 
@@ -564,10 +538,10 @@ void tst_QVideoWidget::objectDestroyed()
 
 void tst_QVideoWidget::setMediaObject()
 {
-    QMediaObject *nullObject = 0;
-    QtTestVideoObject windowObject(new QtTestWindowControl, 0, 0);
-    QtTestVideoObject widgetObject(0, new QtTestWidgetControl, 0);
-    QtTestVideoObject rendererObject(0, 0, new QtTestRendererControl);
+    QMediaObject *nullObject = nullptr;
+    QtTestVideoObject windowObject(new QtTestWindowControl, nullptr, nullptr);
+    QtTestVideoObject widgetObject(nullptr, new QtTestWidgetControl, nullptr);
+    QtTestVideoObject rendererObject(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
 
@@ -606,7 +580,7 @@ void tst_QVideoWidget::setMediaObject()
     QCOMPARE(windowObject.testService->windowRef, 0);
     QCOMPARE(widgetObject.testService->widgetRef, 0);
     QCOMPARE(rendererObject.testService->rendererRef, 1);
-    QVERIFY(rendererObject.testService->rendererControl->surface() != 0);
+    QVERIFY(rendererObject.testService->rendererControl->surface() != nullptr);
 
     rendererObject.unbind(&widget);
     QCOMPARE(widget.mediaObject(), nullObject);
@@ -618,7 +592,7 @@ void tst_QVideoWidget::setMediaObject()
 
 void tst_QVideoWidget::showWindowControl()
 {
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     object.testService->windowControl->setNativeSize(QSize(240, 180));
 
     QtTestVideoWidget widget;
@@ -645,7 +619,7 @@ void tst_QVideoWidget::showWidgetControl()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     QtTestVideoWidget widget;
     object.bind(&widget);
 
@@ -668,14 +642,14 @@ void tst_QVideoWidget::showRendererControl()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
     QtTestVideoWidget widget;
     object.bind(&widget);
 
     widget.show();
     QVERIFY(QTest::qWaitForWindowExposed(&widget));
 
-    QVERIFY(object.testService->rendererControl->surface() != 0);
+    QVERIFY(object.testService->rendererControl->surface() != nullptr);
 
     widget.resize(640, 480);
 
@@ -686,7 +660,7 @@ void tst_QVideoWidget::showRendererControl()
 
 void tst_QVideoWidget::aspectRatioWindowControl()
 {
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     object.testService->windowControl->setAspectRatioMode(Qt::IgnoreAspectRatio);
 
     QtTestVideoWidget widget;
@@ -721,7 +695,7 @@ void tst_QVideoWidget::aspectRatioWidgetControl()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     object.testService->widgetControl->setAspectRatioMode(Qt::IgnoreAspectRatio);
 
     QtTestVideoWidget widget;
@@ -756,7 +730,7 @@ void tst_QVideoWidget::aspectRatioRendererControl()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -793,7 +767,7 @@ void tst_QVideoWidget::sizeHintWindowControl()
 {
     QFETCH(QSize, size);
 
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     QtTestVideoWidget widget;
     object.bind(&widget);
     widget.show();
@@ -813,7 +787,7 @@ void tst_QVideoWidget::sizeHintWidgetControl()
 
     QFETCH(QSize, size);
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     QtTestVideoWidget widget;
     object.bind(&widget);
     widget.show();
@@ -867,7 +841,7 @@ void tst_QVideoWidget::sizeHintRendererControl()
     QFETCH(QSize, pixelAspectRatio);
     QFETCH(QSize, expectedSize);
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
     QtTestVideoWidget widget;
     object.bind(&widget);
 
@@ -886,7 +860,7 @@ void tst_QVideoWidget::sizeHintRendererControl()
 
 void tst_QVideoWidget::fullScreenWindowControl()
 {
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     QtTestVideoWidget widget;
     object.bind(&widget);
     widget.showNormal();
@@ -971,7 +945,7 @@ void tst_QVideoWidget::fullScreenWidgetControl()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     QtTestVideoWidget widget;
     object.bind(&widget);
     widget.showNormal();
@@ -1057,7 +1031,7 @@ void tst_QVideoWidget::fullScreenRendererControl()
     QSKIP("QTBUG-26481 - Crashes on Mac");
 #endif
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
     QtTestVideoWidget widget;
     object.bind(&widget);
     widget.showNormal();
@@ -1151,7 +1125,7 @@ void tst_QVideoWidget::brightnessWindowControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     object.testService->windowControl->setBrightness(controlValue);
 
     QtTestVideoWidget widget;
@@ -1195,7 +1169,7 @@ void tst_QVideoWidget::brightnessWidgetControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     object.testService->widgetControl->setBrightness(controlValue);
 
     QtTestVideoWidget widget;
@@ -1234,7 +1208,7 @@ void tst_QVideoWidget::brightnessRendererControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -1259,7 +1233,7 @@ void tst_QVideoWidget::contrastWindowControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     object.testService->windowControl->setContrast(controlValue);
 
     QtTestVideoWidget widget;
@@ -1300,7 +1274,7 @@ void tst_QVideoWidget::contrastWidgetControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     object.testService->widgetControl->setContrast(controlValue);
 
     QtTestVideoWidget widget;
@@ -1339,7 +1313,7 @@ void tst_QVideoWidget::contrastRendererControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -1364,7 +1338,7 @@ void tst_QVideoWidget::hueWindowControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     object.testService->windowControl->setHue(controlValue);
 
     QtTestVideoWidget widget;
@@ -1404,7 +1378,7 @@ void tst_QVideoWidget::hueWidgetControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     object.testService->widgetControl->setHue(controlValue);
 
     QtTestVideoWidget widget;
@@ -1443,7 +1417,7 @@ void tst_QVideoWidget::hueRendererControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -1468,7 +1442,7 @@ void tst_QVideoWidget::saturationWindowControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(new QtTestWindowControl, 0, 0);
+    QtTestVideoObject object(new QtTestWindowControl, nullptr, nullptr);
     object.testService->windowControl->setSaturation(controlValue);
 
     QtTestVideoWidget widget;
@@ -1507,7 +1481,7 @@ void tst_QVideoWidget::saturationWidgetControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, new QtTestWidgetControl, 0);
+    QtTestVideoObject object(nullptr, new QtTestWidgetControl, nullptr);
     object.testService->widgetControl->setSaturation(controlValue);
 
     QtTestVideoWidget widget;
@@ -1547,7 +1521,7 @@ void tst_QVideoWidget::saturationRendererControl()
     QFETCH(int, value);
     QFETCH(int, expectedValue);
 
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
     object.bind(&widget);
@@ -1573,7 +1547,7 @@ static const uchar rgb32ImageData[] =
 
 void tst_QVideoWidget::paintRendererControl()
 {
-    QtTestVideoObject object(0, 0, new QtTestRendererControl);
+    QtTestVideoObject object(nullptr, nullptr, new QtTestRendererControl);
 
     QtTestVideoWidget widget;
     object.bind(&widget);