GStreamer: use more RAII handle types

Small modernisation by avoiding the need for explicit memory management

Pick-to: 6.6 6.5
Change-Id: I6248be7c9a76780b980276ba444393dabf367281
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
(cherry picked from commit 3371efb74848a66560ad018366f8f26f592c160c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 50 insertions, 34 deletions

diff --git a/src/plugins/multimedia/gstreamer/common/qgst_handle_types_p.h b/src/plugins/multimedia/gstreamer/common/qgst_handle_types_p.h
index 0e3525c14..af43bd4d6 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst_handle_types_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgst_handle_types_p.h
@@ -198,6 +198,30 @@ struct QGstHandleHelper
     using UniqueHandle = QUniqueHandle<QGstSafeObjectHandleTraits>;
 };
 
+template <typename GstType>
+struct QGstMiniObjectHandleHelper
+{
+    struct Traits
+    {
+        using Type = GstType *;
+        static constexpr Type invalidValue() noexcept { return nullptr; }
+        static bool close(Type handle) noexcept
+        {
+            gst_mini_object_unref(GST_MINI_OBJECT_CAST(handle));
+            return true;
+        }
+
+        static Type ref(Type handle) noexcept
+        {
+            gst_mini_object_ref(GST_MINI_OBJECT_CAST(handle));
+            return handle;
+        }
+    };
+
+    using SharedHandle = QSharedHandle<Traits>;
+    using UniqueHandle = QUniqueHandle<Traits>;
+};
+
 } // namespace QGstImpl
 
 using QGstClockHandle = QGstImpl::QGstHandleHelper<GstClock>::UniqueHandle;
@@ -214,6 +238,7 @@ using QUniqueGstStructureHandle = QUniqueHandle<QGstImpl::QUniqueGstStructureHan
 using QUniqueGStringHandle = QUniqueHandle<QGstImpl::QUniqueGStringHandleTraits>;
 using QUniqueGErrorHandle = QUniqueHandle<QGstImpl::QUniqueGErrorHandleTraits>;
 using QFileDescriptorHandle = QUniqueHandle<QGstImpl::QFileDescriptorHandleTraits>;
+using QGstContextHandle = QGstImpl::QGstMiniObjectHandleHelper<GstContext>::UniqueHandle;
 
 #if QT_CONFIG(gstreamer_gl)
 using QGstGLContextHandle = QGstImpl::QGstHandleHelper<GstGLContext>::UniqueHandle;
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
index 92ead9eb7..df8592d8c 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
@@ -374,37 +374,32 @@ bool QGstreamerMediaPlayer::processBusMessage(const QGstreamerMessage &message)
         break;
     }
     case GST_MESSAGE_ERROR: {
-        GError *err;
-        gchar *debug;
+        QUniqueGErrorHandle err;
+        QUniqueGStringHandle debug;
         gst_message_parse_error(gm, &err, &debug);
-        if (err->domain == GST_STREAM_ERROR && err->code == GST_STREAM_ERROR_CODEC_NOT_FOUND)
+        if (err.get()->domain == GST_STREAM_ERROR
+            && err.get()->code == GST_STREAM_ERROR_CODEC_NOT_FOUND)
             emit error(QMediaPlayer::FormatError, tr("Cannot play stream of type: <unknown>"));
         else
-            emit error(QMediaPlayer::ResourceError, QString::fromUtf8(err->message));
+            emit error(QMediaPlayer::ResourceError, QString::fromUtf8(err.get()->message));
         playerPipeline.dumpGraph("error");
         mediaStatusChanged(QMediaPlayer::InvalidMedia);
-        g_error_free(err);
-        g_free(debug);
         break;
     }
     case GST_MESSAGE_WARNING: {
-        GError *err;
-        gchar *debug;
+        QUniqueGErrorHandle err;
+        QUniqueGStringHandle debug;
         gst_message_parse_warning (gm, &err, &debug);
         qCWarning(qLcMediaPlayer) << "Warning:" << err;
         playerPipeline.dumpGraph("warning");
-        g_error_free (err);
-        g_free (debug);
         break;
     }
     case GST_MESSAGE_INFO: {
         if (qLcMediaPlayer().isDebugEnabled()) {
-            GError *err;
-            gchar *debug;
+            QUniqueGErrorHandle err;
+            QUniqueGStringHandle debug;
             gst_message_parse_info (gm, &err, &debug);
             qCDebug(qLcMediaPlayer) << "Info:" << err;
-            g_error_free (err);
-            g_free (debug);
         }
         break;
     }
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp
index 66971a9a5..6c06ed067 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamervideosink.cpp
@@ -4,6 +4,7 @@
 #include "qgstreamervideosink_p.h"
 #include "qgstvideorenderersink_p.h"
 #include "qgstsubtitlesink_p.h"
+#include <qgst_debug_p.h>
 #include <qgstutils_p.h>
 #include <rhi/qrhi.h>
 
@@ -167,12 +168,8 @@ void QGstreamerVideoSink::updateSinkElement()
 
 void QGstreamerVideoSink::unrefGstContexts()
 {
-    if (m_gstGlDisplayContext)
-        gst_context_unref(m_gstGlDisplayContext);
-    m_gstGlDisplayContext = nullptr;
-    if (m_gstGlLocalContext)
-        gst_context_unref(m_gstGlLocalContext);
-    m_gstGlLocalContext = nullptr;
+    m_gstGlDisplayContext.close();
+    m_gstGlLocalContext.close();
     m_eglDisplay = nullptr;
     m_eglImageTargetTexture2D = nullptr;
 }
@@ -244,26 +241,24 @@ void QGstreamerVideoSink::updateGstContexts()
     if (!appContext)
         qWarning() << "Could not create wrappped context for platform:" << glPlatform;
 
-    GError *error = nullptr;
+    QUniqueGErrorHandle error;
     QGstGLContextHandle displayContext;
     gst_gl_display_create_context(gstGlDisplay.get(), appContext.get(), &displayContext, &error);
-    if (error) {
-        qWarning() << "Could not create display context:" << error->message;
-        g_clear_error(&error);
-    }
+    if (error)
+        qWarning() << "Could not create display context:" << error;
 
     appContext.close();
 
-    m_gstGlDisplayContext = gst_context_new(GST_GL_DISPLAY_CONTEXT_TYPE, false);
-    gst_context_set_gl_display(m_gstGlDisplayContext, gstGlDisplay.get());
+    m_gstGlDisplayContext.reset(gst_context_new(GST_GL_DISPLAY_CONTEXT_TYPE, false));
+    gst_context_set_gl_display(m_gstGlDisplayContext.get(), gstGlDisplay.get());
 
-    m_gstGlLocalContext = gst_context_new("gst.gl.local_context", false);
-    GstStructure *structure = gst_context_writable_structure(m_gstGlLocalContext);
+    m_gstGlLocalContext.reset(gst_context_new("gst.gl.local_context", false));
+    GstStructure *structure = gst_context_writable_structure(m_gstGlLocalContext.get());
     gst_structure_set(structure, "context", GST_TYPE_GL_CONTEXT, displayContext.get(), nullptr);
     displayContext.close();
 
     if (!gstPipeline.isNull())
-        gst_element_set_context(gstPipeline.element(), m_gstGlLocalContext);
+        gst_element_set_context(gstPipeline.element(), m_gstGlLocalContext.get());
 #endif // #if QT_CONFIG(gstreamer_gl)
 }
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamervideosink_p.h b/src/plugins/multimedia/gstreamer/common/qgstreamervideosink_p.h
index 730f692a1..0f27d2351 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamervideosink_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamervideosink_p.h
@@ -48,8 +48,8 @@ public:
     void setPipeline(QGstPipeline pipeline);
     bool inStoppedState() const;
 
-    GstContext *gstGlDisplayContext() const { return m_gstGlDisplayContext; }
-    GstContext *gstGlLocalContext() const { return m_gstGlLocalContext; }
+    GstContext *gstGlDisplayContext() const { return m_gstGlDisplayContext.get(); }
+    GstContext *gstGlLocalContext() const { return m_gstGlLocalContext.get(); }
     Qt::HANDLE eglDisplay() const { return m_eglDisplay; }
     QFunctionPointer eglImageTargetTexture2D() const { return m_eglImageTargetTexture2D; }
 
@@ -73,8 +73,9 @@ private:
 
     Qt::HANDLE m_eglDisplay = nullptr;
     QFunctionPointer m_eglImageTargetTexture2D = nullptr;
-    GstContext *m_gstGlLocalContext = nullptr;
-    GstContext *m_gstGlDisplayContext = nullptr;
+
+    QGstContextHandle m_gstGlLocalContext;
+    QGstContextHandle m_gstGlDisplayContext;
 };
 
 QT_END_NAMESPACE