GStreamer: introduce `createFromDevice`

`createFromDevice` internally takes care of the glib reference count.
This should fix a reference count error in the non-pulseaudio
configuration.

Pick-to: 6.5
Change-Id: I28871677c331fb6a40052694de441e61dc3e16a1
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>
Reviewed-by: Mikko Hallamaa <mikko.hallamaa@qt.io>
(cherry picked from commit 07788a4e3d1fe842506cbced237d280cfd4e2386)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit c660888d487fd6a0f33bda858a48b964cc03d764)

7 files changed, 24 insertions, 17 deletions

diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp
index cedc59a96..46d51dff5 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp
@@ -62,7 +62,7 @@ QGStreamerAudioSink::QGStreamerAudioSink(const QAudioDevice &device, QGstAppSrc
     //    g_signal_connect (gstDecodeBin, "pad-added", (GCallback) padAdded, conv);
 
     const auto *audioInfo = static_cast<const QGStreamerAudioDeviceInfo *>(device.handle());
-    gstOutput = QGstElement(gst_device_create_element(audioInfo->gstDevice.get(), nullptr));
+    gstOutput = QGstElement::createFromDevice(audioInfo->gstDevice, nullptr);
 
     gstPipeline.add(gstAppSrc, queue, /*gstDecodeBin, */ audioconvert, gstVolume, gstOutput);
     qLinkGstElements(gstAppSrc, queue, audioconvert, gstVolume, gstOutput);
diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp
index b7c437e43..10b5d02c7 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp
@@ -127,7 +127,7 @@ bool QGStreamerAudioSource::open()
         return false;
     }
 
-    gstInput = QGstElement(gst_device_create_element(deviceInfo->gstDevice.get(), nullptr));
+    gstInput = QGstElement::createFromDevice(deviceInfo->gstDevice);
     if (gstInput.isNull()) {
         setError(QAudio::OpenError);
         setState(QAudio::StoppedState);
diff --git a/src/plugins/multimedia/gstreamer/common/qgst.cpp b/src/plugins/multimedia/gstreamer/common/qgst.cpp
index c67269165..bd951d11a 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgst.cpp
@@ -732,6 +732,19 @@ QGstElement QGstElement::createFromFactory(const char *factory, const char *name
     };
 }
 
+QGstElement QGstElement::createFromDevice(const QGstDeviceHandle &device, const char *name)
+{
+    return createFromDevice(device.get(), name);
+}
+
+QGstElement QGstElement::createFromDevice(GstDevice *device, const char *name)
+{
+    return QGstElement{
+        gst_device_create_element(device, name),
+        QGstElement::NeedsRef,
+    };
+}
+
 QGstPad QGstElement::staticPad(const char *name) const
 {
     return QGstPad(gst_element_get_static_pad(element(), name), HasRef);
diff --git a/src/plugins/multimedia/gstreamer/common/qgst_p.h b/src/plugins/multimedia/gstreamer/common/qgst_p.h
index a0838f960..a63febf44 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgst_p.h
@@ -447,6 +447,8 @@ public:
 
     explicit QGstElement(GstElement *element, RefMode mode = NeedsRef);
     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);
 
     QGstPad staticPad(const char *name) const;
     QGstPad src() const;
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp b/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp
index ad00903e8..a3e9cecb2 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp
@@ -79,14 +79,10 @@ void QGstreamerAudioInput::setAudioDevice(const QAudioDevice &device)
             qCWarning(qLcMediaAudioInput) << "Invalid audio device";
     } else {
         auto *deviceInfo = static_cast<const QGStreamerAudioDeviceInfo *>(m_audioDevice.handle());
-        if (deviceInfo && deviceInfo->gstDevice) {
-            newSrc = QGstElement{
-                gst_device_create_element(deviceInfo->gstDevice.get(), "audiosrc"),
-                QGstElement::HasRef,
-            };
-        } else {
+        if (deviceInfo && deviceInfo->gstDevice)
+            newSrc = QGstElement::createFromDevice(deviceInfo->gstDevice, "audiosrc");
+        else
             qCWarning(qLcMediaAudioInput) << "Invalid audio device";
-        }
     }
 
     if (newSrc.isNull()) {
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
index 0f4d6fa29..d8135a714 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
@@ -90,14 +90,10 @@ void QGstreamerAudioOutput::setAudioDevice(const QAudioDevice &info)
             qCWarning(qLcMediaAudioOutput) << "Invalid audio device";
     } else {
         auto *deviceInfo = static_cast<const QGStreamerAudioDeviceInfo *>(m_audioOutput.handle());
-        if (deviceInfo && deviceInfo->gstDevice) {
-            newSink = QGstElement{
-                gst_device_create_element(deviceInfo->gstDevice.get(), "audiosink"),
-                QGstElement::HasRef,
-            };
-        } else {
+        if (deviceInfo && deviceInfo->gstDevice)
+            newSink = QGstElement::createFromDevice(deviceInfo->gstDevice, "audiosink");
+        else
             qCWarning(qLcMediaAudioOutput) << "Invalid audio device";
-        }
     }
 
     if (newSink.isNull()) {
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp
index 226a08bc9..2e83f2d5c 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp
@@ -90,7 +90,7 @@ void QGstreamerCamera::setCamera(const QCameraDevice &camera)
     } else {
         auto *integration = static_cast<QGstreamerIntegration *>(QGstreamerIntegration::instance());
         auto *device = integration->videoDevice(camera.id());
-        gstNewCamera = QGstElement(gst_device_create_element(device, "camerasrc"));
+        gstNewCamera = QGstElement::createFromDevice(device, "camerasrc");
         if (QGstStructure properties = gst_device_get_properties(device); !properties.isNull()) {
             if (properties.name() == "v4l2deviceprovider")
                 m_v4l2DevicePath = QString::fromUtf8(properties["device.path"].toString());