GStreamer: make all reference counting explicit

When constructing a wrapper object from a gstreamer pointer, we should
always use the explicit reference counting argument.

Pick-to: 6.5
Change-Id: I1a5d589ea48e242b4350ef237312b9e85828c870
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
(cherry picked from commit 157185521ddf4d1ebeefcdd3ebc82319dd88f786)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit ee4776f5c3ea153ec2ca489b2a45032ea5083896)

8 files changed, 22 insertions, 15 deletions

diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
index d286ceb3a..9c1983d7a 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
@@ -100,7 +100,8 @@ void QGstreamerAudioDecoder::configureAppSrcElement(GObject* object, GObject *or
     g_object_get(orig, "source", &appsrc, NULL);
 
     auto *qAppSrc = self->appsrc();
-    qAppSrc->setExternalAppSrc(QGstElement(appsrc.get())); // CHECK: can we `release()`?
+    qAppSrc->setExternalAppSrc(
+            QGstElement(appsrc.get(), QGstElement::NeedsRef)); // CHECK: can we `release()`?
     qAppSrc->setup(self->mDevice);
 }
 #endif
diff --git a/src/plugins/multimedia/gstreamer/common/qgst.cpp b/src/plugins/multimedia/gstreamer/common/qgst.cpp
index 0aafd6499..292ce5e25 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgst.cpp
@@ -698,7 +698,9 @@ bool QGstPad::sendEvent(GstEvent *event)
 
 // QGstClock
 
-QGstClock::QGstClock(const QGstObject &o) : QGstClock(GST_CLOCK(o.object())) { }
+QGstClock::QGstClock(const QGstObject &o) : QGstClock(GST_CLOCK(o.object()), QGstElement::NeedsRef)
+{
+}
 
 QGstClock::QGstClock(GstClock *clock, RefMode mode) : QGstObject(&clock->object, mode) { }
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgst_p.h b/src/plugins/multimedia/gstreamer/common/qgst_p.h
index 5db195c17..efd19edaa 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgst_p.h
@@ -377,7 +377,7 @@ public:
     QGstPad(QGstPad &&) noexcept = default;
 
     explicit QGstPad(const QGstObject &o);
-    explicit QGstPad(GstPad *pad, RefMode mode = NeedsRef);
+    explicit QGstPad(GstPad *pad, RefMode mode);
 
     QGstPad &operator=(const QGstPad &) = default;
     QGstPad &operator=(QGstPad &&) noexcept = default;
@@ -448,7 +448,7 @@ class QGstClock : public QGstObject
 public:
     QGstClock() = default;
     explicit QGstClock(const QGstObject &o);
-    explicit QGstClock(GstClock *clock, RefMode mode = NeedsRef);
+    explicit QGstClock(GstClock *clock, RefMode mode);
 
     GstClock *clock() const;
     GstClockTime time() const;
@@ -466,7 +466,7 @@ public:
     QGstElement &operator=(const QGstElement &) = default;
     QGstElement &operator=(QGstElement &&) noexcept = default;
 
-    explicit QGstElement(GstElement *element, RefMode mode = NeedsRef);
+    explicit QGstElement(GstElement *element, RefMode mode);
     static QGstElement createFromFactory(const char *factory, const char *name = nullptr);
     static QGstElement createFromDevice(const QGstDeviceHandle &, const char *name = nullptr);
     static QGstElement createFromDevice(GstDevice *, const char *name = nullptr);
@@ -493,7 +493,8 @@ public:
     void onPadAdded(T *instance) {
         struct Impl {
             static void callback(GstElement *e, GstPad *pad, gpointer userData) {
-                (static_cast<T *>(userData)->*Member)(QGstElement(e), QGstPad(pad, NeedsRef));
+                (static_cast<T *>(userData)->*Member)(QGstElement(e, NeedsRef),
+                                                      QGstPad(pad, NeedsRef));
             };
         };
 
@@ -503,7 +504,8 @@ public:
     void onPadRemoved(T *instance) {
         struct Impl {
             static void callback(GstElement *e, GstPad *pad, gpointer userData) {
-                (static_cast<T *>(userData)->*Member)(QGstElement(e), QGstPad(pad, NeedsRef));
+                (static_cast<T *>(userData)->*Member)(QGstElement(e, NeedsRef),
+                                                      QGstPad(pad, NeedsRef));
             };
         };
 
@@ -513,7 +515,7 @@ public:
     void onNoMorePads(T *instance) {
         struct Impl {
             static void callback(GstElement *e, gpointer userData) {
-                (static_cast<T *>(userData)->*Member)(QGstElement(e));
+                (static_cast<T *>(userData)->*Member)(QGstElement(e, NeedsRef));
             };
         };
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
index e08319e03..19fffc082 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
@@ -610,7 +610,7 @@ void QGstreamerMediaPlayer::uridecodebinElementAddedCallback(GstElement * /*urid
                                                              GstElement *child,
                                                              QGstreamerMediaPlayer *)
 {
-    QGstElement c(child);
+    QGstElement c(child, QGstElement::NeedsRef);
     qCDebug(qLcMediaPlayer) << "New element added to uridecodebin:" << c.name();
 
     static const GType decodeBinType = [] {
@@ -634,7 +634,7 @@ void QGstreamerMediaPlayer::sourceSetupCallback(GstElement *uridecodebin, GstEle
     qCDebug(qLcMediaPlayer) << "Setting up source:" << g_type_name_from_instance((GTypeInstance*)source);
 
     if (std::string_view("GstRTSPSrc") == g_type_name_from_instance((GTypeInstance *)source)) {
-        QGstElement s(source);
+        QGstElement s(source, QGstElement::NeedsRef);
         int latency{40};
         bool ok{false};
         int v = qEnvironmentVariableIntValue("QT_MEDIA_RTSP_LATENCY", &ok);
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamervideooverlay.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamervideooverlay.cpp
index 96a9dfead..e5041bdab 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamervideooverlay.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamervideooverlay.cpp
@@ -72,7 +72,7 @@ static QGstElement findBestVideoSink()
         if (!gst_element_factory_has_interface(f, "GstVideoOverlay"))
             continue;
 
-        choice = QGstElement(gst_element_factory_create(f, nullptr));
+        choice = QGstElement(gst_element_factory_create(f, nullptr), QGstElement::NeedsRef);
         if (choice.isNull())
             continue;
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp
index 6f5d71106..a4268db34 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp
@@ -114,7 +114,8 @@ QGstreamerVideoSink::QGstreamerVideoSink(QVideoSink *parent)
     }
     sinkBin.addGhostPad(gstQueue, "sink");
 
-    gstSubtitleSink = QGstElement(GST_ELEMENT(QGstSubtitleSink::createSink(this)));
+    gstSubtitleSink =
+            QGstElement(GST_ELEMENT(QGstSubtitleSink::createSink(this)), QGstElement::NeedsRef);
 }
 
 QGstreamerVideoSink::~QGstreamerVideoSink()
@@ -163,7 +164,8 @@ void QGstreamerVideoSink::createQtSink()
     if (gstQtSink)
         gstQtSink.setStateSync(GST_STATE_NULL);
 
-    gstQtSink = QGstElement(reinterpret_cast<GstElement *>(QGstVideoRendererSink::createSink(this)));
+    gstQtSink = QGstElement(reinterpret_cast<GstElement *>(QGstVideoRendererSink::createSink(this)),
+                            QGstElement::NeedsRef);
 }
 
 void QGstreamerVideoSink::updateSinkElement()
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h
index 59d69337f..a85180595 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h
@@ -39,7 +39,7 @@ public:
     bool setCameraFormat(const QCameraFormat &format) override;
 
     void setPipeline(const QGstPipeline &);
-    QGstElement gstElement() const { return QGstElement(gstCameraBin.element()); }
+    QGstElement gstElement() const { return gstCameraBin; }
 #if QT_CONFIG(gstreamer_photography)
     GstPhotography *photography() const;
 #endif
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h
index 7db576023..3d8636cbe 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h
@@ -46,7 +46,7 @@ public:
 
     void setCaptureSession(QPlatformMediaCaptureSession *session);
 
-    QGstElement gstElement() const { return QGstElement{ bin.element() }; }
+    QGstElement gstElement() const { return bin; }
 
 public Q_SLOTS:
     void cameraActiveChanged(bool active);