Validate that gstreamer elements necessary for operation are available

This patch validates that all elements that are necessary to run
the requested functionality are available. Instead of running
constructors directly, the patch uses a static create() function for
each class. This function first tries to instantiate all necessary
GStreamer plugins and then pass them to the class constructor.
If some element is missing the function returns an error message
describing the element.

Pick-to: 6.4
Fixes: QTBUG-106257
Change-Id: I2b9db3f509e9ad5b760fcc251e634a01c687b790
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Reviewed-by: Lars Knoll <lars@knoll.priv.no>

24 files changed, 331 insertions, 92 deletions

diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
index 1bf4c2021..f793a4537 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder.cpp
@@ -36,24 +36,29 @@ typedef enum {
 } GstPlayFlags;
 
 
-
-QGstreamerAudioDecoder::QGstreamerAudioDecoder(QAudioDecoder *parent)
-    : QPlatformAudioDecoder(parent),
-    m_playbin(GST_PIPELINE_CAST(QGstElement("playbin", "playbin").element()))
+QMaybe<QPlatformAudioDecoder *> QGstreamerAudioDecoder::create(QAudioDecoder *parent)
 {
-    if (m_playbin.isNull()) {
-        // ### set error
-        return;
-    }
+    QGstElement audioconvert("audioconvert", "audioconvert");
+    if (!audioconvert)
+        return errorMessageCannotFindElement("audioconvert");
+
+    QGstPipeline playbin = GST_PIPELINE_CAST(QGstElement("playbin", "playbin").element());
+    if (!playbin)
+        return errorMessageCannotFindElement("playbin");
 
+    return new QGstreamerAudioDecoder(playbin, audioconvert, parent);
+}
+
+QGstreamerAudioDecoder::QGstreamerAudioDecoder(QGstPipeline playbin, QGstElement audioconvert,
+                                               QAudioDecoder *parent)
+    : QPlatformAudioDecoder(parent), m_playbin(playbin), m_audioConvert(audioconvert)
+{
     // Sort out messages
     m_playbin.installMessageFilter(this);
 
     // Set the rest of the pipeline up
     setAudioFlags(true);
 
-    m_audioConvert = QGstElement("audioconvert", "audioconvert");
-
     m_outputBin = QGstBin("audio-output-bin");
     m_outputBin.add(m_audioConvert);
 
@@ -61,7 +66,8 @@ QGstreamerAudioDecoder::QGstreamerAudioDecoder(QAudioDecoder *parent)
     m_outputBin.addGhostPad(m_audioConvert, "sink");
 
     g_object_set(m_playbin.object(), "audio-sink", m_outputBin.element(), NULL);
-    g_signal_connect(m_playbin.object(), "deep-notify::source", (GCallback) &QGstreamerAudioDecoder::configureAppSrcElement, (gpointer)this);
+    g_signal_connect(m_playbin.object(), "deep-notify::source",
+                     (GCallback)&QGstreamerAudioDecoder::configureAppSrcElement, (gpointer)this);
 
     // Set volume to 100%
     gdouble volume = 1.0;
@@ -285,8 +291,15 @@ void QGstreamerAudioDecoder::start()
             return;
         }
 
-        if (!m_appSrc)
-            m_appSrc = new QGstAppSrc(this);
+        if (!m_appSrc) {
+            auto maybeAppSrc = QGstAppSrc::create(this);
+            if (maybeAppSrc) {
+                m_appSrc = maybeAppSrc.value();
+            } else {
+                processInvalidMedia(QAudioDecoder::ResourceError, maybeAppSrc.error());
+                return;
+            }
+        }
 
         m_playbin.set("uri", "appsrc://");
     } else {
diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder_p.h b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder_p.h
index ec4ede00d..5a37f8b2a 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder_p.h
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiodecoder_p.h
@@ -20,7 +20,8 @@
 #include <QtCore/qmutex.h>
 #include <QtCore/qurl.h>
 
-#include "private/qplatformaudiodecoder_p.h"
+#include <private/qplatformaudiodecoder_p.h>
+#include <private/qmultimediautils_p.h>
 #include <qgstpipeline_p.h>
 #include "qaudiodecoder.h"
 
@@ -42,7 +43,7 @@ class QGstreamerAudioDecoder
     Q_OBJECT
 
 public:
-    QGstreamerAudioDecoder(QAudioDecoder *parent);
+    static QMaybe<QPlatformAudioDecoder *> create(QAudioDecoder *parent);
     virtual ~QGstreamerAudioDecoder();
 
     QUrl source() const override;
@@ -77,6 +78,8 @@ private slots:
     void updateDuration();
 
 private:
+    QGstreamerAudioDecoder(QGstPipeline playbin, QGstElement audioconvert, QAudioDecoder *parent);
+
     void setAudioFlags(bool wantNativeAudio);
     void addAppSink();
     void removeAppSink();
diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp
index ac98e3fac..cf339d7d7 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink.cpp
@@ -17,23 +17,42 @@
 #include <qgstutils_p.h>
 #include <qgstreamermessage_p.h>
 
+#include <utility>
+
 QT_BEGIN_NAMESPACE
 
-QGStreamerAudioSink::QGStreamerAudioSink(const QAudioDevice &device)
+QMaybe<QPlatformAudioSink *> QGStreamerAudioSink::create(const QAudioDevice &device)
+{
+    auto maybeAppSrc = QGstAppSrc::create();
+    if (!maybeAppSrc)
+        return maybeAppSrc.error();
+
+    QGstElement audioconvert("audioconvert", "conv");
+    if (!audioconvert)
+        return errorMessageCannotFindElement("audioconvert");
+
+    QGstElement volume("volume", "volume");
+    if (!volume)
+        return errorMessageCannotFindElement("volume");
+
+    return new QGStreamerAudioSink(device, maybeAppSrc.value(), audioconvert, volume);
+}
+
+QGStreamerAudioSink::QGStreamerAudioSink(const QAudioDevice &device, QGstAppSrc *appsrc,
+                                         QGstElement audioconvert, QGstElement volume)
     : m_device(device.id()),
-    gstPipeline("pipeline")
+      gstPipeline("pipeline"),
+      gstVolume(std::move(volume)),
+      m_appSrc(appsrc)
 {
     gstPipeline.installMessageFilter(this);
 
-    m_appSrc = new QGstAppSrc;
     connect(m_appSrc, &QGstAppSrc::bytesProcessed, this, &QGStreamerAudioSink::bytesProcessedByAppSrc);
     connect(m_appSrc, &QGstAppSrc::noMoreData, this, &QGStreamerAudioSink::needData);
     gstAppSrc = m_appSrc->element();
 
-    //    gstDecodeBin = gst_element_factory_make ("decodebin", "dec");
     QGstElement queue("queue", "queue");
-    QGstElement conv("audioconvert", "conv");
-    gstVolume = QGstElement("volume", "volume");
+
     if (m_volume != 1.)
         gstVolume.set("volume", m_volume);
 
@@ -43,8 +62,8 @@ QGStreamerAudioSink::QGStreamerAudioSink(const QAudioDevice &device)
     const auto *audioInfo = static_cast<const QGStreamerAudioDeviceInfo *>(device.handle());
     gstOutput = gst_device_create_element(audioInfo->gstDevice, nullptr);
 
-    gstPipeline.add(gstAppSrc, queue, /*gstDecodeBin, */ conv, gstVolume, gstOutput);
-    gstAppSrc.link(queue, conv, gstVolume, gstOutput);
+    gstPipeline.add(gstAppSrc, queue, /*gstDecodeBin, */ audioconvert, gstVolume, gstOutput);
+    gstAppSrc.link(queue, audioconvert, gstVolume, gstOutput);
 }
 
 QGStreamerAudioSink::~QGStreamerAudioSink()
diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink_p.h b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink_p.h
index 6a034f7e9..26d2c9b28 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink_p.h
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosink_p.h
@@ -26,6 +26,7 @@
 #include "qaudio.h"
 #include "qaudiodevice.h"
 #include <private/qaudiosystem_p.h>
+#include <private/qmultimediautils_p.h>
 
 #include <qgst_p.h>
 #include <qgstpipeline_p.h>
@@ -42,7 +43,7 @@ class QGStreamerAudioSink
     Q_OBJECT
 
 public:
-    QGStreamerAudioSink(const QAudioDevice &device);
+    static QMaybe<QPlatformAudioSink *> create(const QAudioDevice &device);
     ~QGStreamerAudioSink();
 
     void start(QIODevice *device) override;
@@ -68,6 +69,9 @@ private Q_SLOTS:
     void needData();
 
 private:
+    QGStreamerAudioSink(const QAudioDevice &device, QGstAppSrc *appsrc, QGstElement audioconvert,
+                        QGstElement volume);
+
     void setState(QAudio::State state);
     void setError(QAudio::Error error);
 
diff --git a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp
index d1b00840a..77d09be49 100644
--- a/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp
+++ b/src/plugins/multimedia/gstreamer/audio/qgstreameraudiosource.cpp
@@ -159,6 +159,7 @@ bool QGStreamerAudioSource::open()
 
     QGstElement conv("audioconvert", "conv");
     gstVolume = QGstElement("volume", "volume");
+    Q_ASSERT(gstVolume);
     if (m_volume != 1.)
         gstVolume.set("volume", m_volume);
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgst_p.h b/src/plugins/multimedia/gstreamer/common/qgst_p.h
index 40897ad9d..ec2f9cb58 100644
--- a/src/plugins/multimedia/gstreamer/common/qgst_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgst_p.h
@@ -290,6 +290,8 @@ public:
             gst_object_unref(m_object);
     }
 
+    explicit operator bool() const { return bool(m_object); }
+
     friend bool operator==(const QGstObject &a, const QGstObject &b)
     { return a.m_object == b.m_object; }
     friend bool operator!=(const QGstObject &a, const QGstObject &b)
@@ -430,6 +432,10 @@ public:
     QGstElement(const char *factory, const char *name = nullptr)
         : QGstElement(gst_element_factory_make(factory, name), NeedsRef)
     {
+#ifndef QT_NO_DEBUG
+        if (!m_object)
+            qWarning() << "Failed to make element" << name << "from factory" << factory;
+#endif
     }
 
     bool linkFiltered(const QGstElement &next, const QGstMutableCaps &caps)
@@ -595,6 +601,11 @@ inline QGstCaps QGValue::toCaps() const
     return QGstCaps(gst_value_get_caps(value));
 }
 
+inline QString errorMessageCannotFindElement(std::string_view element)
+{
+    return QStringLiteral("Could not find the %1 GStreamer element").arg(element.data());
+}
+
 QT_END_NAMESPACE
 
 #endif
diff --git a/src/plugins/multimedia/gstreamer/common/qgstappsrc.cpp b/src/plugins/multimedia/gstreamer/common/qgstappsrc.cpp
index 053b3ce8e..b3e4837b4 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstappsrc.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstappsrc.cpp
@@ -10,12 +10,18 @@
 
 Q_LOGGING_CATEGORY(qLcAppSrc, "qt.multimedia.appsrc")
 
-QGstAppSrc::QGstAppSrc(QObject *parent)
-    : QObject(parent)
+QMaybe<QGstAppSrc *> QGstAppSrc::create(QObject *parent)
+{
+    QGstElement appsrc("appsrc", "appsrc");
+    if (!appsrc)
+        return errorMessageCannotFindElement("appsrc");
+
+    return new QGstAppSrc(appsrc, parent);
+}
+
+QGstAppSrc::QGstAppSrc(QGstElement appsrc, QObject *parent)
+    : QObject(parent), m_appSrc(std::move(appsrc))
 {
-    m_appSrc = QGstElement("appsrc", "appsrc");
-    if (m_appSrc.isNull())
-        qWarning() << "Could not create GstAppSrc.";
 }
 
 QGstAppSrc::~QGstAppSrc()
diff --git a/src/plugins/multimedia/gstreamer/common/qgstappsrc_p.h b/src/plugins/multimedia/gstreamer/common/qgstappsrc_p.h
index 0266e0312..8d5d2b0c1 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstappsrc_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstappsrc_p.h
@@ -16,6 +16,7 @@
 //
 
 #include <private/qtmultimediaglobal_p.h>
+#include <private/qmultimediautils_p.h>
 #include <qaudioformat.h>
 
 #include <QtCore/qobject.h>
@@ -34,7 +35,7 @@ class Q_MULTIMEDIA_EXPORT QGstAppSrc  : public QObject
 {
     Q_OBJECT
 public:
-    QGstAppSrc(QObject *parent = 0);
+    static QMaybe<QGstAppSrc *> create(QObject *parent = nullptr);
     ~QGstAppSrc();
 
     bool setup(QIODevice *stream = nullptr, qint64 offset = 0);
@@ -61,6 +62,8 @@ private Q_SLOTS:
 
     void streamDestroyed();
 private:
+    QGstAppSrc(QGstElement appsrc, QObject *parent);
+
     bool setStream(QIODevice *, qint64 offset);
     bool isStreamValid() const
     {
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp b/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp
index 455e98f51..01ea33694 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput.cpp
@@ -14,17 +14,33 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include <utility>
+
 Q_LOGGING_CATEGORY(qLcMediaAudioInput, "qt.multimedia.audioInput")
 
 QT_BEGIN_NAMESPACE
 
-QGstreamerAudioInput::QGstreamerAudioInput(QAudioInput *parent)
-  : QObject(parent),
-    QPlatformAudioInput(parent),
-    gstAudioInput("audioInput")
+QMaybe<QPlatformAudioInput *> QGstreamerAudioInput::create(QAudioInput *parent)
+{
+    QGstElement autoaudiosrc("autoaudiosrc", "autoaudiosrc");
+    if (!autoaudiosrc)
+        return errorMessageCannotFindElement("autoaudiosrc");
+
+    QGstElement volume("volume", "volume");
+    if (!volume)
+        return errorMessageCannotFindElement("volume");
+
+    return new QGstreamerAudioInput(autoaudiosrc, volume, parent);
+}
+
+QGstreamerAudioInput::QGstreamerAudioInput(QGstElement autoaudiosrc, QGstElement volume,
+                                           QAudioInput *parent)
+    : QObject(parent),
+      QPlatformAudioInput(parent),
+      gstAudioInput("audioInput"),
+      audioSrc(std::move(autoaudiosrc)),
+      audioVolume(std::move(volume))
 {
-    audioSrc = QGstElement("autoaudiosrc", "autoaudiosrc");
-    audioVolume = QGstElement("volume", "volume");
     gstAudioInput.add(audioSrc, audioVolume);
     audioSrc.link(audioVolume);
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput_p.h b/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput_p.h
index 2586898b2..b74a21718 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudioinput_p.h
@@ -16,6 +16,7 @@
 //
 
 #include <private/qtmultimediaglobal_p.h>
+#include <private/qmultimediautils_p.h>
 #include <qaudiodevice.h>
 
 #include <QtCore/qobject.h>
@@ -34,7 +35,7 @@ class Q_MULTIMEDIA_EXPORT QGstreamerAudioInput : public QObject, public QPlatfor
     Q_OBJECT
 
 public:
-    QGstreamerAudioInput(QAudioInput *parent);
+    static QMaybe<QPlatformAudioInput *> create(QAudioInput *parent);
     ~QGstreamerAudioInput();
 
     int volume() const;
@@ -54,6 +55,8 @@ Q_SIGNALS:
     void volumeChanged(int);
 
 private:
+    QGstreamerAudioInput(QGstElement autoaudiosrc, QGstElement volume, QAudioInput *parent);
+
     float m_volume = 1.;
     bool m_muted = false;
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
index 9891e0b6c..4d43226d2 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput.cpp
@@ -14,20 +14,45 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include <utility>
+
 Q_LOGGING_CATEGORY(qLcMediaAudioOutput, "qt.multimedia.audiooutput")
 
 QT_BEGIN_NAMESPACE
 
-QGstreamerAudioOutput::QGstreamerAudioOutput(QAudioOutput *parent)
-  : QObject(parent),
-    QPlatformAudioOutput(parent),
-    gstAudioOutput("audioOutput")
+QMaybe<QPlatformAudioOutput *> QGstreamerAudioOutput::create(QAudioOutput *parent)
+{
+    QGstElement audioconvert("audioconvert", "audioConvert");
+    if (!audioconvert)
+        return errorMessageCannotFindElement("audioconvert");
+
+    QGstElement audioresample("audioresample", "audioResample");
+    if (!audioresample)
+        return errorMessageCannotFindElement("audioresample");
+
+    QGstElement volume("volume", "volume");
+    if (!volume)
+        return errorMessageCannotFindElement("volume");
+
+    QGstElement autoaudiosink("autoaudiosink", "autoAudioSink");
+    if (!autoaudiosink)
+        return errorMessageCannotFindElement("autoaudiosink");
+
+    return new QGstreamerAudioOutput(audioconvert, audioresample, volume, autoaudiosink, parent);
+}
+
+QGstreamerAudioOutput::QGstreamerAudioOutput(QGstElement audioconvert, QGstElement audioresample,
+                                             QGstElement volume, QGstElement autoaudiosink,
+                                             QAudioOutput *parent)
+    : QObject(parent),
+      QPlatformAudioOutput(parent),
+      gstAudioOutput("audioOutput"),
+      audioConvert(std::move(audioconvert)),
+      audioResample(std::move(audioresample)),
+      audioVolume(std::move(volume)),
+      audioSink(std::move(autoaudiosink))
 {
     audioQueue = QGstElement("queue", "audioQueue");
-    audioConvert = QGstElement("audioconvert", "audioConvert");
-    audioResample = QGstElement("audioresample", "audioResample");
-    audioVolume = QGstElement("volume", "volume");
-    audioSink = QGstElement("autoaudiosink", "autoAudioSink");
     gstAudioOutput.add(audioQueue, audioConvert, audioResample, audioVolume, audioSink);
     audioQueue.link(audioConvert, audioResample, audioVolume, audioSink);
 
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput_p.h b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput_p.h
index a44e6589a..e9d1e1b72 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstreameraudiooutput_p.h
@@ -16,6 +16,7 @@
 //
 
 #include <private/qtmultimediaglobal_p.h>
+#include <private/qmultimediautils_p.h>
 #include <qaudiodevice.h>
 
 #include <QtCore/qobject.h>
@@ -34,7 +35,7 @@ class Q_MULTIMEDIA_EXPORT QGstreamerAudioOutput : public QObject, public QPlatfo
     Q_OBJECT
 
 public:
-    QGstreamerAudioOutput(QAudioOutput *parent);
+    static QMaybe<QPlatformAudioOutput *> create(QAudioOutput *parent);
     ~QGstreamerAudioOutput();
 
     void setAudioDevice(const QAudioDevice &) override;
@@ -50,6 +51,9 @@ Q_SIGNALS:
     void volumeChanged(int);
 
 private:
+    QGstreamerAudioOutput(QGstElement audioconvert, QGstElement audioresample, QGstElement volume,
+                          QGstElement autoaudiosink, QAudioOutput *parent);
+
     QAudioDevice m_audioOutput;
 
     // Gst elements
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
index 9fd65aef2..eb0e8f427 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer.cpp
@@ -29,9 +29,8 @@ Q_LOGGING_CATEGORY(qLcMediaPlayer, "qt.multimedia.player")
 
 QT_BEGIN_NAMESPACE
 
-QGstreamerMediaPlayer::TrackSelector::TrackSelector(TrackType type, const char *name)
-    : selector(QGstElement("input-selector", name)),
-      type(type)
+QGstreamerMediaPlayer::TrackSelector::TrackSelector(TrackType type, QGstElement selector)
+    : selector(selector), type(type)
 {
     selector.set("sync-streams", true);
     selector.set("sync-mode", 1 /*clock*/);
@@ -74,17 +73,49 @@ QGstreamerMediaPlayer::TrackSelector &QGstreamerMediaPlayer::trackSelector(Track
     return ts;
 }
 
-QGstreamerMediaPlayer::QGstreamerMediaPlayer(QMediaPlayer *parent)
+QMaybe<QPlatformMediaPlayer *> QGstreamerMediaPlayer::create(QMediaPlayer *parent)
+{
+    auto videoOutput = QGstreamerVideoOutput::create();
+    if (!videoOutput)
+        return videoOutput.error();
+
+    QGstElement decodebin("decodebin", nullptr);
+    if (!decodebin)
+        return errorMessageCannotFindElement("decodebin");
+
+    QGstElement videoInputSelector("input-selector", "videoInputSelector");
+    if (!videoInputSelector)
+        return errorMessageCannotFindElement("input-selector");
+
+    QGstElement audioInputSelector("input-selector", "audioInputSelector");
+    if (!audioInputSelector)
+        return errorMessageCannotFindElement("input-selector");
+
+    QGstElement subTitleInputSelector("input-selector", "subTitleInputSelector");
+    if (!subTitleInputSelector)
+        return errorMessageCannotFindElement("input-selector");
+
+    return new QGstreamerMediaPlayer(videoOutput.value(), decodebin, videoInputSelector,
+                                     audioInputSelector, subTitleInputSelector, parent);
+}
+
+QGstreamerMediaPlayer::QGstreamerMediaPlayer(QGstreamerVideoOutput *videoOutput,
+                                             QGstElement decodebin,
+                                             QGstElement videoInputSelector,
+                                             QGstElement audioInputSelector,
+                                             QGstElement subTitleInputSelector,
+                                             QMediaPlayer *parent)
     : QObject(parent),
       QPlatformMediaPlayer(parent),
-      trackSelectors{{{ VideoStream, "videoInputSelector" },
-                      { AudioStream, "audioInputSelector" },
-                      { SubtitleStream, "subTitleInputSelector" }}},
-      playerPipeline("playerPipeline")
+      trackSelectors{ { { VideoStream, videoInputSelector },
+                        { AudioStream, audioInputSelector },
+                        { SubtitleStream, subTitleInputSelector } } },
+      playerPipeline("playerPipeline"),
+      gstVideoOutput(videoOutput)
 {
     playerPipeline.setFlushOnConfigChanges(true);
 
-    gstVideoOutput = new QGstreamerVideoOutput(this);
+    gstVideoOutput->setParent(this);
     gstVideoOutput->setPipeline(playerPipeline);
 
     for (auto &ts : trackSelectors)
@@ -100,7 +131,6 @@ QGstreamerMediaPlayer::QGstreamerMediaPlayer(QMediaPlayer *parent)
      * This is ugly. We get the GType of decodebin so we can quickly detect
      * when a decodebin is added to uridecodebin so we can set the
      * post-stream-topology setting to TRUE */
-    auto decodebin = QGstElement("decodebin", nullptr);
     decodebinType = G_OBJECT_TYPE(decodebin.element());
     connect(&positionUpdateTimer, &QTimer::timeout, this, &QGstreamerMediaPlayer::updatePosition);
 }
@@ -639,10 +669,21 @@ void QGstreamerMediaPlayer::setMedia(const QUrl &content, QIODevice *stream)
         return;
 
     if (m_stream) {
-        if (!m_appSrc)
-            m_appSrc = new QGstAppSrc(this);
+        if (!m_appSrc) {
+            auto maybeAppSrc = QGstAppSrc::create(this);
+            if (maybeAppSrc) {
+                m_appSrc = maybeAppSrc.value();
+            } else {
+                emit error(QMediaPlayer::ResourceError, maybeAppSrc.error());
+                return;
+            }
+        }
         src = m_appSrc->element();
         decoder = QGstElement("decodebin", "decoder");
+        if (!decoder) {
+            emit error(QMediaPlayer::ResourceError, errorMessageCannotFindElement("decodebin"));
+            return;
+        }
         decoder.set("post-stream-topology", true);
         playerPipeline.add(src, decoder);
         src.link(decoder);
@@ -652,6 +693,10 @@ void QGstreamerMediaPlayer::setMedia(const QUrl &content, QIODevice *stream)
     } else {
         // use uridecodebin
         decoder = QGstElement("uridecodebin", "uridecoder");
+        if (!decoder) {
+            emit error(QMediaPlayer::ResourceError, errorMessageCannotFindElement("uridecodebin"));
+            return;
+        }
         playerPipeline.add(decoder);
         // can't set post-stream-topology to true, as uridecodebin doesn't have the property. Use a hack
         decoder.connect("element-added", GCallback(QGstreamerMediaPlayer::uridecodebinElementAddedCallback), this);
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer_p.h b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer_p.h
index 7afad3ba7..3664f34b7 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamermediaplayer_p.h
@@ -18,6 +18,7 @@
 #include <QtCore/qstack.h>
 #include <private/qplatformmediaplayer_p.h>
 #include <private/qtmultimediaglobal_p.h>
+#include <private/qmultimediautils_p.h>
 #include <qurl.h>
 #include <qgst_p.h>
 #include <qgstpipeline_p.h>
@@ -43,7 +44,7 @@ class Q_MULTIMEDIA_EXPORT QGstreamerMediaPlayer
     Q_OBJECT
 
 public:
-    QGstreamerMediaPlayer(QMediaPlayer *parent = 0);
+    static QMaybe<QPlatformMediaPlayer *> create(QMediaPlayer *parent = nullptr);
     ~QGstreamerMediaPlayer();
 
     qint64 position() const override;
@@ -86,8 +87,12 @@ public Q_SLOTS:
     void updatePosition() { positionChanged(position()); }
 
 private:
+    QGstreamerMediaPlayer(QGstreamerVideoOutput *videoOutput, QGstElement decodebin,
+                          QGstElement videoInputSelector, QGstElement audioInputSelector,
+                          QGstElement subTitleInputSelector, QMediaPlayer *parent);
+
     struct TrackSelector {
-        TrackSelector(TrackType, const char *name);
+        TrackSelector(TrackType, QGstElement selector);
         QGstPad createInputPad();
         void removeInputPad(QGstPad pad);
         void removeAllInputPads();
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput.cpp b/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput.cpp
index 919d43559..9385030e0 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput.cpp
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput.cpp
@@ -13,13 +13,27 @@ Q_LOGGING_CATEGORY(qLcMediaVideoOutput, "qt.multimedia.videooutput")
 
 QT_BEGIN_NAMESPACE
 
-QGstreamerVideoOutput::QGstreamerVideoOutput(QObject *parent)
+QMaybe<QGstreamerVideoOutput *> QGstreamerVideoOutput::create(QObject *parent)
+{
+    QGstElement videoConvert("videoconvert", "videoConvert");
+    if (!videoConvert)
+        return errorMessageCannotFindElement("videoconvert");
+
+    QGstElement videoSink("fakesink", "fakeVideoSink");
+    if (!videoSink)
+        return errorMessageCannotFindElement("fakesink");
+
+    return new QGstreamerVideoOutput(videoConvert, videoSink, parent);
+}
+
+QGstreamerVideoOutput::QGstreamerVideoOutput(QGstElement convert, QGstElement sink,
+                                             QObject *parent)
     : QObject(parent),
-      gstVideoOutput("videoOutput")
+      gstVideoOutput("videoOutput"),
+      videoConvert(std::move(convert)),
+      videoSink(std::move(sink))
 {
     videoQueue = QGstElement("queue", "videoQueue");
-    videoConvert = QGstElement("videoconvert", "videoConvert");
-    videoSink = QGstElement("fakesink", "fakeVideoSink");
     videoSink.set("sync", true);
     gstVideoOutput.add(videoQueue, videoConvert, videoSink);
     if (!videoQueue.link(videoConvert, videoSink))
@@ -52,6 +66,7 @@ void QGstreamerVideoOutput::setVideoSink(QVideoSink *sink)
         isFakeSink = false;
     } else {
         gstSink = QGstElement("fakesink", "fakevideosink");
+        Q_ASSERT(gstSink);
         gstSink.set("sync", true);
         isFakeSink = true;
     }
diff --git a/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput_p.h b/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput_p.h
index 74652aa77..a7175dc36 100644
--- a/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput_p.h
+++ b/src/plugins/multimedia/gstreamer/common/qgstreamervideooutput_p.h
@@ -17,6 +17,7 @@
 
 #include <QtCore/qobject.h>
 #include <private/qtmultimediaglobal_p.h>
+#include <private/qmultimediautils_p.h>
 #include <qgst_p.h>
 #include <qgstpipeline_p.h>
 #include <qwaitcondition.h>
@@ -33,7 +34,7 @@ class Q_MULTIMEDIA_EXPORT QGstreamerVideoOutput : public QObject
     Q_OBJECT
 
 public:
-    QGstreamerVideoOutput(QObject *parent = 0);
+    static QMaybe<QGstreamerVideoOutput *> create(QObject *parent = nullptr);
     ~QGstreamerVideoOutput();
 
     void setVideoSink(QVideoSink *sink);
@@ -49,6 +50,8 @@ public:
     void flushSubtitles();
 
 private:
+    QGstreamerVideoOutput(QGstElement videoConvert, QGstElement videoSink, QObject *parent);
+
     void doLinkSubtitleStream();
 
     QPointer<QGstreamerVideoSink> m_videoSink;
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp
index bfb3bdf8d..f55038932 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera.cpp
@@ -16,14 +16,37 @@
 
 #include <QtCore/qdebug.h>
 
-QGstreamerCamera::QGstreamerCamera(QCamera *camera)
-        : QPlatformCamera(camera)
+QMaybe<QPlatformCamera *> QGstreamerCamera::create(QCamera *camera)
+{
+    QGstElement videotestsrc("videotestsrc");
+    if (!videotestsrc)
+        return errorMessageCannotFindElement("videotestsrc");
+
+    QGstElement capsFilter("capsfilter", "videoCapsFilter");
+    if (!capsFilter)
+        return errorMessageCannotFindElement("capsfilter");
+
+    QGstElement videoconvert("videoconvert", "videoConvert");
+    if (!videoconvert)
+        return errorMessageCannotFindElement("videoconvert");
+
+    QGstElement videoscale("videoscale", "videoScale");
+    if (!videoscale)
+        return errorMessageCannotFindElement("videoscale");
+
+    return new QGstreamerCamera(videotestsrc, capsFilter, videoconvert, videoscale, camera);
+}
+
+QGstreamerCamera::QGstreamerCamera(QGstElement videotestsrc, QGstElement capsFilter,
+                                   QGstElement videoconvert, QGstElement videoscale,
+                                   QCamera *camera)
+    : QPlatformCamera(camera),
+      gstCamera(std::move(videotestsrc)),
+      gstCapsFilter(std::move(capsFilter)),
+      gstVideoConvert(std::move(videoconvert)),
+      gstVideoScale(std::move(videoscale))
 {
-    gstCamera = QGstElement("videotestsrc");
-    gstCapsFilter = QGstElement("capsfilter", "videoCapsFilter");
     gstDecode = QGstElement("identity");
-    gstVideoConvert = QGstElement("videoconvert", "videoConvert");
-    gstVideoScale = QGstElement("videoscale", "videoScale");
     gstCameraBin = QGstBin("camerabin");
     gstCameraBin.add(gstCamera, gstCapsFilter, gstDecode, gstVideoConvert, gstVideoScale);
     gstCamera.link(gstCapsFilter, gstDecode, gstVideoConvert, gstVideoScale);
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h
index bd2c815ad..bab24d8c6 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamercamera_p.h
@@ -1,7 +1,6 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
-
 #ifndef QGSTREAMERCAMERACONTROL_H
 #define QGSTREAMERCAMERACONTROL_H
 
@@ -18,6 +17,7 @@
 
 #include <QHash>
 #include <private/qplatformcamera_p.h>
+#include <private/qmultimediautils_p.h>
 #include "qgstreamermediacapture_p.h"
 #include <qgst_p.h>
 
@@ -27,7 +27,8 @@ class QGstreamerCamera : public QPlatformCamera
 {
     Q_OBJECT
 public:
-    QGstreamerCamera(QCamera *camera);
+    static QMaybe<QPlatformCamera *> create(QCamera *camera);
+
     virtual ~QGstreamerCamera();
 
     bool isActive() const override;
@@ -64,6 +65,9 @@ public:
     bool isV4L2Camera() const { return !m_v4l2Device.isEmpty(); }
 
 private:
+    QGstreamerCamera(QGstElement videotestsrc, QGstElement capsFilter, QGstElement videoconvert,
+                     QGstElement videoscale, QCamera *camera);
+
     void updateCameraProperties();
 #if QT_CONFIG(linux_v4l)
     void initV4L2Controls();
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture.cpp b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture.cpp
index 229698289..fcd373f81 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture.cpp
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture.cpp
@@ -12,6 +12,7 @@
 
 #include <QtCore/QDebug>
 #include <QtCore/QDir>
+#include <utility>
 #include <qstandardpaths.h>
 
 #include <qloggingcategory.h>
@@ -20,9 +21,30 @@ QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(qLcImageCapture, "qt.multimedia.imageCapture")
 
-QGstreamerImageCapture::QGstreamerImageCapture(QImageCapture *parent)
-  : QPlatformImageCapture(parent),
-    QGstreamerBufferProbe(ProbeBuffers)
+QMaybe<QPlatformImageCapture *> QGstreamerImageCapture::create(QImageCapture *parent)
+{
+    QGstElement videoconvert("videoconvert", "imageCaptureConvert");
+    if (!videoconvert)
+        return errorMessageCannotFindElement("videoconvert");
+
+    QGstElement jpegenc("jpegenc", "jpegEncoder");
+    if (!jpegenc)
+        return errorMessageCannotFindElement("jpegenc");
+
+    QGstElement jifmux("jifmux", "jpegMuxer");
+    if (!jifmux)
+        return errorMessageCannotFindElement("jifmux");
+
+    return new QGstreamerImageCapture(videoconvert, jpegenc, jifmux, parent);
+}
+
+QGstreamerImageCapture::QGstreamerImageCapture(QGstElement videoconvert, QGstElement jpegenc,
+                                               QGstElement jifmux, QImageCapture *parent)
+    : QPlatformImageCapture(parent),
+      QGstreamerBufferProbe(ProbeBuffers),
+      videoConvert(std::move(videoconvert)),
+      encoder(std::move(jpegenc)),
+      muxer(std::move(jifmux))
 {
     bin = QGstBin("imageCaptureBin");
 
@@ -34,9 +56,6 @@ QGstreamerImageCapture::QGstreamerImageCapture(QImageCapture *parent)
     queue.set("max-size-bytes", uint(0));
     queue.set("max-size-time", quint64(0));
 
-    videoConvert = QGstElement("videoconvert", "imageCaptureConvert");
-    encoder = QGstElement("jpegenc", "jpegEncoder");
-    muxer = QGstElement("jifmux", "jpegMuxer");
     sink = QGstElement("fakesink","imageCaptureSink");
     // imageCaptureSink do not wait for a preroll buffer when going READY -> PAUSED
     // as no buffer will arrive until capture() is called
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h
index b76649631..87d805802 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamerimagecapture_p.h
@@ -1,7 +1,6 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
-
 #ifndef QGSTREAMERIMAGECAPTURECONTROL_H
 #define QGSTREAMERIMAGECAPTURECONTROL_H
 
@@ -17,6 +16,7 @@
 //
 
 #include <private/qplatformimagecapture_p.h>
+#include <private/qmultimediautils_p.h>
 #include "qgstreamermediacapture_p.h"
 #include "qgstreamerbufferprobe_p.h"
 
@@ -32,7 +32,7 @@ class QGstreamerImageCapture : public QPlatformImageCapture, private QGstreamerB
 {
     Q_OBJECT
 public:
-    QGstreamerImageCapture(QImageCapture *parent);
+    static QMaybe<QPlatformImageCapture *> create(QImageCapture *parent);
     virtual ~QGstreamerImageCapture();
 
     bool isReadyForCapture() const override;
@@ -53,6 +53,9 @@ public Q_SLOTS:
     void onCameraChanged();
 
 private:
+    QGstreamerImageCapture(QGstElement videoconvert, QGstElement jpegenc, QGstElement jifmux,
+                           QImageCapture *parent);
+
     int doCapture(const QString &fileName);
     static gboolean saveImageFilter(GstElement *element, GstBuffer *buffer, GstPad *pad, void *appdata);
 
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture.cpp b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture.cpp
index 4a1c7f6b5..be34995ee 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture.cpp
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture.cpp
@@ -38,11 +38,19 @@ static void unlinkTeeFromPad(QGstElement tee, QGstPad sink)
     tee.releaseRequestPad(source);
 }
 
+QMaybe<QPlatformMediaCaptureSession *> QGstreamerMediaCapture::create()
+{
+    auto videoOutput = QGstreamerVideoOutput::create();
+    if (!videoOutput)
+        return videoOutput.error();
+
+    return new QGstreamerMediaCapture(videoOutput.value());
+}
 
-QGstreamerMediaCapture::QGstreamerMediaCapture()
-    : gstPipeline("pipeline")
+QGstreamerMediaCapture::QGstreamerMediaCapture(QGstreamerVideoOutput *videoOutput)
+    : gstPipeline("pipeline"), gstVideoOutput(videoOutput)
 {
-    gstVideoOutput = new QGstreamerVideoOutput(this);
+    gstVideoOutput->setParent(this);
     gstVideoOutput->setIsPreview();
     gstVideoOutput->setPipeline(gstPipeline);
 
@@ -181,6 +189,7 @@ void QGstreamerMediaCapture::linkEncoder(QGstPad audioSink, QGstPad videoSink)
         auto caps = gst_pad_get_current_caps(gstVideoTee.sink().pad());
 
         encoderVideoCapsFilter = QGstElement("capsfilter", "encoderVideoCapsFilter");
+        Q_ASSERT(encoderVideoCapsFilter);
         encoderVideoCapsFilter.set("caps", QGstMutableCaps(caps));
 
         gstPipeline.add(encoderVideoCapsFilter);
@@ -195,6 +204,7 @@ void QGstreamerMediaCapture::linkEncoder(QGstPad audioSink, QGstPad videoSink)
         auto caps = gst_pad_get_current_caps(gstAudioTee.sink().pad());
 
         encoderAudioCapsFilter = QGstElement("capsfilter", "encoderAudioCapsFilter");
+        Q_ASSERT(encoderAudioCapsFilter);
         encoderAudioCapsFilter.set("caps", QGstMutableCaps(caps));
 
         gstPipeline.add(encoderAudioCapsFilter);
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture_p.h b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture_p.h
index 245cffe71..3aa6d6c9f 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture_p.h
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediacapture_p.h
@@ -38,7 +38,7 @@ class QGstreamerMediaCapture : public QPlatformMediaCaptureSession
     Q_OBJECT
 
 public:
-    QGstreamerMediaCapture();
+    static QMaybe<QPlatformMediaCaptureSession *> create();
     virtual ~QGstreamerMediaCapture();
 
     QPlatformCamera *camera() override;
@@ -64,6 +64,8 @@ public:
     QGstreamerVideoSink *gstreamerVideoSink() const;
 
 private:
+    QGstreamerMediaCapture(QGstreamerVideoOutput *videoOutput);
+
     friend QGstreamerMediaEncoder;
     // Gst elements
     QGstPipeline gstPipeline;
diff --git a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediaencoder.cpp b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediaencoder.cpp
index 43472f657..f88524123 100644
--- a/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediaencoder.cpp
+++ b/src/plugins/multimedia/gstreamer/mediacapture/qgstreamermediaencoder.cpp
@@ -261,11 +261,13 @@ void QGstreamerMediaEncoder::record(QMediaEncoderSettings &settings)
     Q_ASSERT(!actualSink.isEmpty());
 
     gstEncoder = QGstElement("encodebin", "encodebin");
+    Q_ASSERT(gstEncoder);
     auto *encodingProfile = createEncodingProfile(settings);
     g_object_set (gstEncoder.object(), "profile", encodingProfile, nullptr);
     gst_encoding_profile_unref(encodingProfile);
 
     gstFileSink = QGstElement("filesink", "filesink");
+    Q_ASSERT(gstFileSink);
     gstFileSink.set("location", QFile::encodeName(actualSink.toLocalFile()).constData());
     gstFileSink.set("async", false);
 
diff --git a/src/plugins/multimedia/gstreamer/qgstreamerintegration.cpp b/src/plugins/multimedia/gstreamer/qgstreamerintegration.cpp
index 817aae1c2..e84f0301f 100644
--- a/src/plugins/multimedia/gstreamer/qgstreamerintegration.cpp
+++ b/src/plugins/multimedia/gstreamer/qgstreamerintegration.cpp
@@ -61,22 +61,22 @@ const QGstreamerFormatInfo *QGstreamerIntegration::gstFormatsInfo() const
 
 QMaybe<QPlatformAudioDecoder *> QGstreamerIntegration::createAudioDecoder(QAudioDecoder *decoder)
 {
-    return new QGstreamerAudioDecoder(decoder);
+    return QGstreamerAudioDecoder::create(decoder);
 }
 
 QMaybe<QPlatformMediaCaptureSession *> QGstreamerIntegration::createCaptureSession()
 {
-    return new QGstreamerMediaCapture();
+    return QGstreamerMediaCapture::create();
 }
 
 QMaybe<QPlatformMediaPlayer *> QGstreamerIntegration::createPlayer(QMediaPlayer *player)
 {
-    return new QGstreamerMediaPlayer(player);
+    return QGstreamerMediaPlayer::create(player);
 }
 
 QMaybe<QPlatformCamera *> QGstreamerIntegration::createCamera(QCamera *camera)
 {
-    return new QGstreamerCamera(camera);
+    return QGstreamerCamera::create(camera);
 }
 
 QMaybe<QPlatformMediaRecorder *> QGstreamerIntegration::createRecorder(QMediaRecorder *recorder)
@@ -86,7 +86,7 @@ QMaybe<QPlatformMediaRecorder *> QGstreamerIntegration::createRecorder(QMediaRec
 
 QMaybe<QPlatformImageCapture *> QGstreamerIntegration::createImageCapture(QImageCapture *imageCapture)
 {
-    return new QGstreamerImageCapture(imageCapture);
+    return QGstreamerImageCapture::create(imageCapture);
 }
 
 QMaybe<QPlatformVideoSink *> QGstreamerIntegration::createVideoSink(QVideoSink *sink)
@@ -96,12 +96,12 @@ QMaybe<QPlatformVideoSink *> QGstreamerIntegration::createVideoSink(QVideoSink *
 
 QMaybe<QPlatformAudioInput *> QGstreamerIntegration::createAudioInput(QAudioInput *q)
 {
-    return new QGstreamerAudioInput(q);
+    return QGstreamerAudioInput::create(q);
 }
 
 QMaybe<QPlatformAudioOutput *> QGstreamerIntegration::createAudioOutput(QAudioOutput *q)
 {
-    return new QGstreamerAudioOutput(q);
+    return QGstreamerAudioOutput::create(q);
 }
 
 GstDevice *QGstreamerIntegration::videoDevice(const QByteArray &id) const