GStreamer: fix memory leaks.

Many GStreamer objects were not properly managed or never released.

Change-Id: I38b3854e8b9e2264b5b647f331d3bb16b886e2d6
Reviewed-by: Andrew den Exter <andrew.den.exter@qinetic.com.au>

20 files changed, 134 insertions, 41 deletions

diff --git a/src/gsttools/qgstappsrc.cpp b/src/gsttools/qgstappsrc.cpp
index 8917bda85..2c9f64c34 100644
--- a/src/gsttools/qgstappsrc.cpp
+++ b/src/gsttools/qgstappsrc.cpp
@@ -72,7 +72,11 @@ bool QGstAppSrc::setup(GstElement* appsrc)
     if (m_setup || m_stream == 0 || appsrc == 0)
         return false;
 
+    if (m_appSrc)
+        gst_object_unref(G_OBJECT(m_appSrc));
+
     m_appSrc = GST_APP_SRC(appsrc);
+    gst_object_ref(G_OBJECT(m_appSrc));
     gst_app_src_set_callbacks(m_appSrc, (GstAppSrcCallbacks*)&m_callbacks, this, (GDestroyNotify)&QGstAppSrc::destroy_notify);
 
     g_object_get(G_OBJECT(m_appSrc), "max-bytes", &m_maxBytes, NULL);
diff --git a/src/gsttools/qgstcodecsinfo.cpp b/src/gsttools/qgstcodecsinfo.cpp
index ade79fd44..6db9b016a 100644
--- a/src/gsttools/qgstcodecsinfo.cpp
+++ b/src/gsttools/qgstcodecsinfo.cpp
@@ -93,6 +93,9 @@ QGstCodecsInfo::QGstCodecsInfo(QGstCodecsInfo::ElementType elementType)
 
         gst_caps_remove_structure(caps, 0);
     }
+
+    gst_caps_unref(caps);
+    gst_caps_unref(allCaps);
 #else
     Q_UNUSED(elementType);
 #endif // GST_CHECK_VERSION(0,10,31)
@@ -143,7 +146,7 @@ GstCaps* QGstCodecsInfo::supportedElementCaps(GstElementFactoryListType elementT
             padTemplates = padTemplates->next;
 
             if (padTemplate->direction == padDirection) {
-                const GstCaps *caps = gst_static_caps_get(&padTemplate->static_caps);
+                GstCaps *caps = gst_static_caps_get(&padTemplate->static_caps);
                 for (uint i=0; i<gst_caps_get_size(caps); i++) {
                     const GstStructure *structure = gst_caps_get_structure(caps, i);
 
@@ -173,6 +176,7 @@ GstCaps* QGstCodecsInfo::supportedElementCaps(GstElementFactoryListType elementT
 
                     gst_caps_merge_structure(res, newStructure);
                 }
+                gst_caps_unref(caps);
             }
         }
     }
diff --git a/src/gsttools/qgstreamergltexturerenderer.cpp b/src/gsttools/qgstreamergltexturerenderer.cpp
index dda04792e..85199e00e 100644
--- a/src/gsttools/qgstreamergltexturerenderer.cpp
+++ b/src/gsttools/qgstreamergltexturerenderer.cpp
@@ -216,6 +216,7 @@ GstElement *QGstreamerGLTextureRenderer::videoSink()
 
             GstPad *pad = gst_element_get_static_pad(m_videoSink,"sink");
             m_bufferProbeId = gst_pad_add_buffer_probe(pad, G_CALLBACK(padBufferProbe), this);
+            gst_object_unref(GST_OBJECT(pad));
         }
     }
 
diff --git a/src/gsttools/qgstreamervideorenderer.cpp b/src/gsttools/qgstreamervideorenderer.cpp
index 5b0b0d7dd..36c9f78d0 100644
--- a/src/gsttools/qgstreamervideorenderer.cpp
+++ b/src/gsttools/qgstreamervideorenderer.cpp
@@ -41,6 +41,7 @@
 
 #include "qgstreamervideorenderer_p.h"
 #include <private/qvideosurfacegstsink_p.h>
+#include <private/qgstutils_p.h>
 #include <qabstractvideosurface.h>
 
 #include <QDebug>
@@ -62,8 +63,7 @@ GstElement *QGstreamerVideoRenderer::videoSink()
 {
     if (!m_videoSink && m_surface) {
         m_videoSink = QVideoSurfaceGstSink::createSink(m_surface);
-        gst_object_ref(GST_OBJECT(m_videoSink)); //Take ownership
-        gst_object_sink(GST_OBJECT(m_videoSink));
+        qt_gst_object_ref_sink(GST_OBJECT(m_videoSink)); //Take ownership
     }
 
     return reinterpret_cast<GstElement*>(m_videoSink);
diff --git a/src/gsttools/qgstreamervideowidget.cpp b/src/gsttools/qgstreamervideowidget.cpp
index 8297040c1..7e11bfb21 100644
--- a/src/gsttools/qgstreamervideowidget.cpp
+++ b/src/gsttools/qgstreamervideowidget.cpp
@@ -137,8 +137,7 @@ void QGstreamerVideoWidgetControl::createVideoWidget()
     if (!m_videoSink)
         m_videoSink = gst_element_factory_make ("ximagesink", NULL);
 
-    gst_object_ref (GST_OBJECT (m_videoSink)); //Take ownership
-    gst_object_sink (GST_OBJECT (m_videoSink));
+    qt_gst_object_ref_sink(GST_OBJECT (m_videoSink)); //Take ownership
 
 
 }
@@ -219,6 +218,7 @@ void QGstreamerVideoWidgetControl::updateNativeVideoSize()
         //find video native size to update video widget size hint
         GstPad *pad = gst_element_get_static_pad(m_videoSink,"sink");
         GstCaps *caps = gst_pad_get_negotiated_caps(pad);
+        gst_object_unref(GST_OBJECT(pad));
 
         if (caps) {
             m_widget->setNativeSize(QGstUtils::capsCorrectedResolution(caps));
diff --git a/src/gsttools/qgstreamervideowindow.cpp b/src/gsttools/qgstreamervideowindow.cpp
index 70d321575..2dc351065 100644
--- a/src/gsttools/qgstreamervideowindow.cpp
+++ b/src/gsttools/qgstreamervideowindow.cpp
@@ -63,11 +63,11 @@ QGstreamerVideoWindow::QGstreamerVideoWindow(QObject *parent, const char *elemen
         m_videoSink = gst_element_factory_make("xvimagesink", NULL);
 
     if (m_videoSink) {
-        gst_object_ref(GST_OBJECT(m_videoSink)); //Take ownership
-        gst_object_sink(GST_OBJECT(m_videoSink));
+        qt_gst_object_ref_sink(GST_OBJECT(m_videoSink)); //Take ownership
 
         GstPad *pad = gst_element_get_static_pad(m_videoSink,"sink");
         m_bufferProbeId = gst_pad_add_buffer_probe(pad, G_CALLBACK(padBufferProbe), this);
+        gst_object_unref(GST_OBJECT(pad));
     }
 }
 
@@ -114,6 +114,7 @@ bool QGstreamerVideoWindow::processSyncMessage(const QGstreamerMessage &message)
 
         GstPad *pad = gst_element_get_static_pad(m_videoSink,"sink");
         m_bufferProbeId = gst_pad_add_buffer_probe(pad, G_CALLBACK(padBufferProbe), this);
+        gst_object_unref(GST_OBJECT(pad));
 
         return true;
     }
@@ -319,6 +320,7 @@ void QGstreamerVideoWindow::updateNativeVideoSize()
         //find video native size to update video widget size hint
         GstPad *pad = gst_element_get_static_pad(m_videoSink,"sink");
         GstCaps *caps = gst_pad_get_negotiated_caps(pad);
+        gst_object_unref(GST_OBJECT(pad));
 
         if (caps) {
             m_nativeSize = QGstUtils::capsCorrectedResolution(caps);
diff --git a/src/gsttools/qgstutils.cpp b/src/gsttools/qgstutils.cpp
index e93b46753..41bd005bd 100644
--- a/src/gsttools/qgstutils.cpp
+++ b/src/gsttools/qgstutils.cpp
@@ -401,4 +401,22 @@ QMultimedia::SupportEstimate QGstUtils::hasSupport(const QString &mimeType,
     return QMultimedia::MaybeSupported;
 }
 
+void qt_gst_object_ref_sink(gpointer object)
+{
+#if (GST_VERSION_MAJOR >= 0) && (GST_VERSION_MINOR >= 10) && (GST_VERSION_MICRO >= 24)
+    gst_object_ref_sink(object);
+#else
+    g_return_if_fail (GST_IS_OBJECT(object));
+
+    GST_OBJECT_LOCK(object);
+    if (G_LIKELY(GST_OBJECT_IS_FLOATING(object))) {
+        GST_OBJECT_FLAG_UNSET(object, GST_OBJECT_FLOATING);
+        GST_OBJECT_UNLOCK(object);
+    } else {
+        GST_OBJECT_UNLOCK(object);
+        gst_object_ref(object);
+    }
+#endif
+}
+
 QT_END_NAMESPACE
diff --git a/src/multimedia/gsttools_headers/qgstutils_p.h b/src/multimedia/gsttools_headers/qgstutils_p.h
index 568580264..eea1e15d9 100644
--- a/src/multimedia/gsttools_headers/qgstutils_p.h
+++ b/src/multimedia/gsttools_headers/qgstutils_p.h
@@ -78,6 +78,8 @@ namespace QGstUtils {
                                              const QSet<QString> &supportedMimeTypeSet);
 }
 
+void qt_gst_object_ref_sink(gpointer object);
+
 QT_END_NAMESPACE
 
 #endif
diff --git a/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecoderserviceplugin.cpp b/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecoderserviceplugin.cpp
index d34c10e10..3085d1391 100644
--- a/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecoderserviceplugin.cpp
+++ b/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecoderserviceplugin.cpp
@@ -147,6 +147,7 @@ void QGstreamerAudioDecoderServicePlugin::updateSupportedMimeTypes() const
                                         }
                                     }
                                 }
+                                gst_caps_unref(caps);
                             }
                         }
                         gst_object_unref (factory);
diff --git a/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecodersession.cpp b/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecodersession.cpp
index 5bcf1aa54..9f1a765ec 100644
--- a/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecodersession.cpp
+++ b/src/plugins/gstreamer/audiodecoder/qgstreameraudiodecodersession.cpp
@@ -158,6 +158,8 @@ void QGstreamerAudioDecoderSession::configureAppSrcElement(GObject* object, GObj
 
     if (!self->appsrc()->setup(appsrc))
         qWarning()<<"Could not setup appsrc element";
+
+    g_object_unref(G_OBJECT(appsrc));
 }
 #endif
 
@@ -372,7 +374,8 @@ void QGstreamerAudioDecoderSession::start()
         if (mFormat.isValid()) {
             setAudioFlags(false);
             GstCaps *caps = QGstUtils::capsForAudioFormat(mFormat);
-            gst_app_sink_set_caps(m_appSink, caps); // appsink unrefs caps
+            gst_app_sink_set_caps(m_appSink, caps);
+            gst_caps_unref(caps);
         } else {
             // We want whatever the native audio format is
             setAudioFlags(true);
diff --git a/src/plugins/gstreamer/camerabin/camerabinaudioencoder.cpp b/src/plugins/gstreamer/camerabin/camerabinaudioencoder.cpp
index 0fa854cc5..332891a47 100644
--- a/src/plugins/gstreamer/camerabin/camerabinaudioencoder.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinaudioencoder.cpp
@@ -114,11 +114,15 @@ GstEncodingProfile *CameraBinAudioEncoder::createProfile()
     else
         caps = gst_caps_from_string(codec.toLatin1());
 
-    return (GstEncodingProfile *)gst_encoding_audio_profile_new(
-                                        caps,
-                                        !preset.isEmpty() ? preset.toLatin1().constData() : NULL, //preset
-                                        NULL,   //restriction
-                                        0);     //presence
+    GstEncodingProfile *profile = (GstEncodingProfile *)gst_encoding_audio_profile_new(
+                caps,
+                !preset.isEmpty() ? preset.toLatin1().constData() : NULL, //preset
+                NULL,   //restriction
+                0);     //presence
+
+    gst_caps_unref(caps);
+
+    return profile;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/gstreamer/camerabin/camerabincontainer.cpp b/src/plugins/gstreamer/camerabin/camerabincontainer.cpp
index 4c2a3bda9..44eb36818 100644
--- a/src/plugins/gstreamer/camerabin/camerabincontainer.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabincontainer.cpp
@@ -124,11 +124,15 @@ GstEncodingContainerProfile *CameraBinContainer::createProfile()
         caps = gst_caps_from_string(format.toLatin1());
     }
 
-    return (GstEncodingContainerProfile *)gst_encoding_container_profile_new(
-                                        "camerabin2_profile",
-                                        (gchar *)"custom camera profile",
-                                        caps,
-                                        NULL); //preset
+    GstEncodingContainerProfile *profile = (GstEncodingContainerProfile *)gst_encoding_container_profile_new(
+                "camerabin2_profile",
+                (gchar *)"custom camera profile",
+                caps,
+                NULL); //preset
+
+    gst_caps_unref(caps);
+
+    return profile;
 }
 
 /*!
diff --git a/src/plugins/gstreamer/camerabin/camerabinrecorder.cpp b/src/plugins/gstreamer/camerabin/camerabinrecorder.cpp
index 4ac0d942e..7cef82a69 100644
--- a/src/plugins/gstreamer/camerabin/camerabinrecorder.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinrecorder.cpp
@@ -191,10 +191,14 @@ GstEncodingContainerProfile *CameraBinRecorder::videoProfile()
         GstEncodingProfile *audioProfile = m_session->audioEncodeControl()->createProfile();
         GstEncodingProfile *videoProfile = m_session->videoEncodeControl()->createProfile();
 
-        if (audioProfile)
-            gst_encoding_container_profile_add_profile(containerProfile, audioProfile);
-        if (videoProfile)
-            gst_encoding_container_profile_add_profile(containerProfile, videoProfile);
+        if (audioProfile) {
+            if (!gst_encoding_container_profile_add_profile(containerProfile, audioProfile))
+                gst_encoding_profile_unref(audioProfile);
+        }
+        if (videoProfile) {
+            if (!gst_encoding_container_profile_add_profile(containerProfile, videoProfile))
+                gst_encoding_profile_unref(videoProfile);
+        }
     }
 
     return containerProfile;
diff --git a/src/plugins/gstreamer/camerabin/camerabinsession.cpp b/src/plugins/gstreamer/camerabin/camerabinsession.cpp
index 8ca6bfd83..6e3448ffe 100644
--- a/src/plugins/gstreamer/camerabin/camerabinsession.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinsession.cpp
@@ -61,6 +61,7 @@
 #include "camerabincapturebufferformat.h"
 #include <private/qgstreamerbushelper_p.h>
 #include <private/qgstreamervideorendererinterface_p.h>
+#include <private/qgstutils_p.h>
 #include <qmediarecorder.h>
 
 #ifdef HAVE_GST_PHOTOGRAPHY
@@ -108,9 +109,6 @@
 #define CAMERABIN_IMAGE_MODE 1
 #define CAMERABIN_VIDEO_MODE 2
 
-#define gstRef(element) { gst_object_ref(GST_OBJECT(element)); gst_object_sink(GST_OBJECT(element)); }
-#define gstUnref(element) { if (element) { gst_object_unref(GST_OBJECT(element)); element = 0; } }
-
 #define PREVIEW_CAPS_4_3 \
     "video/x-raw-rgb, width = (int) 640, height = (int) 480"
 
@@ -146,7 +144,7 @@ CameraBinSession::CameraBinSession(QObject *parent)
 {
     m_camerabin = gst_element_factory_make("camerabin2", "camerabin2");
     g_signal_connect(G_OBJECT(m_camerabin), "notify::idle", G_CALLBACK(updateBusyStatus), this);
-    gstRef(m_camerabin);
+    qt_gst_object_ref_sink(m_camerabin);
 
     m_bus = gst_element_get_bus(m_camerabin);
 
@@ -192,9 +190,11 @@ CameraBinSession::~CameraBinSession()
 
         gst_element_set_state(m_camerabin, GST_STATE_NULL);
         gst_element_get_state(m_camerabin, NULL, NULL, GST_CLOCK_TIME_NONE);
-        gstUnref(m_camerabin);
-        gstUnref(m_viewfinderElement);
+        gst_object_unref(GST_OBJECT(m_bus));
+        gst_object_unref(GST_OBJECT(m_camerabin));
     }
+    if (m_viewfinderElement)
+        gst_object_unref(GST_OBJECT(m_viewfinderElement));
 }
 
 #ifdef HAVE_GST_PHOTOGRAPHY
@@ -239,7 +239,7 @@ bool CameraBinSession::setupCameraBin()
             qWarning() << "Staring camera without viewfinder available";
             m_viewfinderElement = gst_element_factory_make("fakesink", NULL);
         }
-        gst_object_ref(GST_OBJECT(m_viewfinderElement));
+        qt_gst_object_ref_sink(GST_OBJECT(m_viewfinderElement));
         gst_element_set_state(m_camerabin, GST_STATE_NULL);
         g_object_set(G_OBJECT(m_camerabin), VIEWFINDER_SINK_PROPERTY, m_viewfinderElement, NULL);
     }
@@ -438,6 +438,9 @@ GstElement *CameraBinSession::buildCameraSource()
     if (m_videoSrc != videoSrc)
         g_object_set(G_OBJECT(m_camerabin), CAMERA_SOURCE_PROPERTY, m_videoSrc, NULL);
 
+    if (videoSrc)
+        gst_object_unref(GST_OBJECT(videoSrc));
+
     return m_videoSrc;
 }
 
@@ -680,10 +683,12 @@ void CameraBinSession::setState(QCamera::State newState)
 
             m_recorderControl->applySettings();
 
+            GstEncodingContainerProfile *profile = m_recorderControl->videoProfile();
             g_object_set (G_OBJECT(m_camerabin),
                           "video-profile",
-                          m_recorderControl->videoProfile(),
+                          profile,
                           NULL);
+            gst_encoding_profile_unref(profile);
 
             setAudioCaptureCaps();
 
@@ -803,6 +808,7 @@ void CameraBinSession::setMetaData(const QMap<QByteArray, QVariant> &data)
                 }
             }
         }
+        gst_iterator_free(elements);
     }
 }
 
diff --git a/src/plugins/gstreamer/camerabin/camerabinvideoencoder.cpp b/src/plugins/gstreamer/camerabin/camerabinvideoencoder.cpp
index cb479d8df..146e150ec 100644
--- a/src/plugins/gstreamer/camerabin/camerabinvideoencoder.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinvideoencoder.cpp
@@ -175,6 +175,8 @@ GstEncodingProfile *CameraBinVideoEncoder::createProfile()
                 NULL, //restriction
                 1); //presence
 
+    gst_caps_unref(caps);
+
     gst_encoding_video_profile_set_pass(profile, 0);
     gst_encoding_video_profile_set_variableframerate(profile, TRUE);
 
diff --git a/src/plugins/gstreamer/mediacapture/qgstreameraudioencode.cpp b/src/plugins/gstreamer/mediacapture/qgstreameraudioencode.cpp
index 88c86b3b5..e735566dd 100644
--- a/src/plugins/gstreamer/mediacapture/qgstreameraudioencode.cpp
+++ b/src/plugins/gstreamer/mediacapture/qgstreameraudioencode.cpp
@@ -196,6 +196,8 @@ GstElement *QGstreamerAudioEncode::createEncoder()
         //qDebug() << "set caps filter:" << gst_caps_to_string(caps);
 
         g_object_set(G_OBJECT(capsFilter), "caps", caps, NULL);
+
+        gst_caps_unref(caps);
     }
 
     if (encoderElement) {
diff --git a/src/plugins/gstreamer/mediacapture/qgstreamercaptureserviceplugin.cpp b/src/plugins/gstreamer/mediacapture/qgstreamercaptureserviceplugin.cpp
index de07d2707..657b9806f 100644
--- a/src/plugins/gstreamer/mediacapture/qgstreamercaptureserviceplugin.cpp
+++ b/src/plugins/gstreamer/mediacapture/qgstreamercaptureserviceplugin.cpp
@@ -261,6 +261,7 @@ void QGstreamerCaptureServicePlugin::updateSupportedMimeTypes() const
                                         }
                                     }
                                 }
+                                gst_caps_unref(caps);
                             }
                         }
                         gst_object_unref (factory);
diff --git a/src/plugins/gstreamer/mediacapture/qgstreamercapturesession.cpp b/src/plugins/gstreamer/mediacapture/qgstreamercapturesession.cpp
index d7473327f..518a66bc0 100644
--- a/src/plugins/gstreamer/mediacapture/qgstreamercapturesession.cpp
+++ b/src/plugins/gstreamer/mediacapture/qgstreamercapturesession.cpp
@@ -49,6 +49,7 @@
 #include <private/qgstreamervideorendererinterface_p.h>
 #include <private/qgstreameraudioprobecontrol_p.h>
 #include <private/qgstreamerbushelper_p.h>
+#include <private/qgstutils_p.h>
 
 #include <gst/gsttagsetter.h>
 #include <gst/gstversion.h>
@@ -64,9 +65,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#define gstRef(element) { gst_object_ref(GST_OBJECT(element)); gst_object_sink(GST_OBJECT(element)); }
-#define gstUnref(element) { if (element) { gst_object_unref(GST_OBJECT(element)); element = 0; } }
-
 QGstreamerCaptureSession::QGstreamerCaptureSession(QGstreamerCaptureSession::CaptureMode captureMode, QObject *parent)
     :QObject(parent),
      m_state(StoppedState),
@@ -97,7 +95,7 @@ QGstreamerCaptureSession::QGstreamerCaptureSession(QGstreamerCaptureSession::Cap
      m_passPrerollImage(false)
 {
     m_pipeline = gst_pipeline_new("media-capture-pipeline");
-    gstRef(m_pipeline);
+    qt_gst_object_ref_sink(m_pipeline);
 
     m_bus = gst_element_get_bus(m_pipeline);
     m_busHelper = new QGstreamerBusHelper(m_bus, this);
@@ -116,6 +114,7 @@ QGstreamerCaptureSession::~QGstreamerCaptureSession()
 {
     setState(StoppedState);
     gst_element_set_state(m_pipeline, GST_STATE_NULL);
+    gst_object_unref(GST_OBJECT(m_bus));
     gst_object_unref(GST_OBJECT(m_pipeline));
 }
 
@@ -160,6 +159,7 @@ GstElement *QGstreamerCaptureSession::buildEncodeBin()
         gst_bin_add(GST_BIN(encodeBin), audioEncoder);
 
         if (!gst_element_link_many(audioConvert, audioQueue, m_audioVolume, audioEncoder, muxer, NULL)) {
+            m_audioVolume = 0;
             gst_object_unref(encodeBin);
             return 0;
         }
@@ -333,6 +333,7 @@ GstElement *QGstreamerCaptureSession::buildVideoPreview()
 
             g_object_set(G_OBJECT(capsFilter), "caps", caps, NULL);
 
+            gst_caps_unref(caps);
         }
 
         // add ghostpads
@@ -501,6 +502,7 @@ GstElement *QGstreamerCaptureSession::buildImageCapture()
     GstPad *pad = gst_element_get_static_pad(queue, "src");
     Q_ASSERT(pad);
     gst_pad_add_buffer_probe(pad, G_CALLBACK(passImageFilter), this);
+    gst_object_unref(GST_OBJECT(pad));
 
     g_object_set(G_OBJECT(sink), "signal-handoffs", TRUE, NULL);
     g_signal_connect(G_OBJECT(sink), "handoff",
@@ -531,6 +533,7 @@ void QGstreamerCaptureSession::captureImage(int requestId, const QString &fileNa
 
 
 #define REMOVE_ELEMENT(element) { if (element) {gst_bin_remove(GST_BIN(m_pipeline), element); element = 0;} }
+#define UNREF_ELEMENT(element) { if (element) { gst_object_unref(GST_OBJECT(element)); element = 0; } }
 
 bool QGstreamerCaptureSession::rebuildGraph(QGstreamerCaptureSession::PipelineMode newMode)
 {
@@ -562,6 +565,9 @@ bool QGstreamerCaptureSession::rebuildGraph(QGstreamerCaptureSession::PipelineMo
                 if (ok) {
                     gst_bin_add_many(GST_BIN(m_pipeline), m_audioSrc, m_audioPreview, NULL);
                     ok &= gst_element_link(m_audioSrc, m_audioPreview);
+                } else {
+                    UNREF_ELEMENT(m_audioSrc);
+                    UNREF_ELEMENT(m_audioPreview);
                 }
             }
             if (m_captureMode & Video || m_captureMode & Image) {
@@ -582,6 +588,12 @@ bool QGstreamerCaptureSession::rebuildGraph(QGstreamerCaptureSession::PipelineMo
                     ok &= gst_element_link(m_videoTee, m_videoPreviewQueue);
                     ok &= gst_element_link(m_videoPreviewQueue, m_videoPreview);
                     ok &= gst_element_link(m_videoTee, m_imageCaptureBin);
+                } else {
+                    UNREF_ELEMENT(m_videoSrc);
+                    UNREF_ELEMENT(m_videoTee);
+                    UNREF_ELEMENT(m_videoPreviewQueue);
+                    UNREF_ELEMENT(m_videoPreview);
+                    UNREF_ELEMENT(m_imageCaptureBin);
                 }
             }
             break;
@@ -631,6 +643,11 @@ bool QGstreamerCaptureSession::rebuildGraph(QGstreamerCaptureSession::PipelineMo
                     ok &= gst_element_link(m_audioTee, m_audioPreviewQueue);
                     ok &= gst_element_link(m_audioPreviewQueue, m_audioPreview);
                     ok &= gst_element_link(m_audioTee, m_encodeBin);
+                } else {
+                    UNREF_ELEMENT(m_audioSrc);
+                    UNREF_ELEMENT(m_audioPreview);
+                    UNREF_ELEMENT(m_audioTee);
+                    UNREF_ELEMENT(m_audioPreviewQueue);
                 }
             }
 
@@ -648,6 +665,11 @@ bool QGstreamerCaptureSession::rebuildGraph(QGstreamerCaptureSession::PipelineMo
                     ok &= gst_element_link(m_videoSrc, m_videoTee);
                     ok &= gst_element_link(m_videoTee, m_videoPreviewQueue);
                     ok &= gst_element_link(m_videoPreviewQueue, m_videoPreview);
+                } else {
+                    UNREF_ELEMENT(m_videoSrc);
+                    UNREF_ELEMENT(m_videoTee);
+                    UNREF_ELEMENT(m_videoPreviewQueue);
+                    UNREF_ELEMENT(m_videoPreview);
                 }
 
                 if (ok && (m_captureMode & Video))
@@ -917,6 +939,7 @@ void QGstreamerCaptureSession::setMetaData(const QMap<QByteArray, QVariant> &dat
             }
 
         }
+        gst_iterator_free(elements);
     }
 }
 
@@ -1096,8 +1119,10 @@ void QGstreamerCaptureSession::removeAudioBufferProbe()
         return;
 
     GstPad *pad = getAudioProbePad();
-    if (pad)
+    if (pad) {
         gst_pad_remove_buffer_probe(pad, m_audioBufferProbeId);
+        gst_object_unref(G_OBJECT(pad));
+    }
 
     m_audioBufferProbeId = -1;
 }
@@ -1107,8 +1132,10 @@ void QGstreamerCaptureSession::addAudioBufferProbe()
     Q_ASSERT(m_audioBufferProbeId == -1);
 
     GstPad *pad = getAudioProbePad();
-    if (pad)
+    if (pad) {
         m_audioBufferProbeId = gst_pad_add_buffer_probe(pad, G_CALLBACK(padAudioBufferProbe), this);
+        gst_object_unref(G_OBJECT(pad));
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/gstreamer/mediacapture/qgstreamervideoencode.cpp b/src/plugins/gstreamer/mediacapture/qgstreamervideoencode.cpp
index 73112491f..c29735037 100644
--- a/src/plugins/gstreamer/mediacapture/qgstreamervideoencode.cpp
+++ b/src/plugins/gstreamer/mediacapture/qgstreamervideoencode.cpp
@@ -286,6 +286,8 @@ GstElement *QGstreamerVideoEncode::createEncoder()
         //qDebug() << "set video caps filter:" << gst_caps_to_string(caps);
 
         g_object_set(G_OBJECT(capsFilter), "caps", caps, NULL);
+
+        gst_caps_unref(caps);
     }
 
     return GST_ELEMENT(encoderBin);
diff --git a/src/plugins/gstreamer/mediaplayer/qgstreamerplayersession.cpp b/src/plugins/gstreamer/mediaplayer/qgstreamerplayersession.cpp
index f5b4be72b..f4ac59420 100644
--- a/src/plugins/gstreamer/mediaplayer/qgstreamerplayersession.cpp
+++ b/src/plugins/gstreamer/mediaplayer/qgstreamerplayersession.cpp
@@ -48,6 +48,7 @@
 #include <private/gstvideoconnector_p.h>
 #include <private/qgstutils_p.h>
 #include <private/playlistfileparser_p.h>
+#include <private/qgstutils_p.h>
 
 #include <gst/gstvalue.h>
 #include <gst/base/gstbasesrc.h>
@@ -157,17 +158,20 @@ QGstreamerPlayerSession::QGstreamerPlayerSession(QObject *parent)
         }
     }
 
-    m_videoOutputBin = gst_bin_new("video-output-bin");
-    gst_object_ref(GST_OBJECT(m_videoOutputBin));
-
-    m_videoIdentity = GST_ELEMENT(g_object_new(gst_video_connector_get_type(), 0));
+    m_videoIdentity = GST_ELEMENT(g_object_new(gst_video_connector_get_type(), 0)); // floating ref
     g_signal_connect(G_OBJECT(m_videoIdentity), "connection-failed", G_CALLBACK(insertColorSpaceElement), (gpointer)this);
+
     m_colorSpace = gst_element_factory_make("ffmpegcolorspace", "ffmpegcolorspace-vo");
-    gst_object_ref(GST_OBJECT(m_colorSpace));
+    // might not get a parent, take ownership to avoid leak
+    qt_gst_object_ref_sink(GST_OBJECT(m_colorSpace));
 
     m_nullVideoSink = gst_element_factory_make("fakesink", NULL);
     g_object_set(G_OBJECT(m_nullVideoSink), "sync", true, NULL);
     gst_object_ref(GST_OBJECT(m_nullVideoSink));
+
+    m_videoOutputBin = gst_bin_new("video-output-bin");
+    // might not get a parent, take ownership to avoid leak
+    qt_gst_object_ref_sink(GST_OBJECT(m_videoOutputBin));
     gst_bin_add_many(GST_BIN(m_videoOutputBin), m_videoIdentity, m_nullVideoSink, NULL);
     gst_element_link(m_videoIdentity, m_nullVideoSink);
 
@@ -238,6 +242,8 @@ void QGstreamerPlayerSession::configureAppSrcElement(GObject* object, GObject *o
 
     if (!self->appsrc()->setup(appsrc))
         qWarning()<<"Could not setup appsrc element";
+
+    g_object_unref(G_OBJECT(appsrc));
 }
 #endif