GStreamer: improved logic for window and widget controls usage.

Provide these controls only when the xvimagesink gstreamer element is
available. This allows QVideoWidget to fallback to QVideoRendererControl
when xvimagesink is not available.

Task-number: QTBUG-41618
Change-Id: I59f90ea8857c7ec0ffa08be9804e5458d95b79c4
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/gsttools/qgstreamervideowidget.cpp

@@ -93,6 +93,22 @@ QGstreamerVideoWidgetControl::QGstreamerVideoWidgetControl(QObject *parent)
     , m_widget(0)
     , m_fullScreen(false)
 {
+    m_videoSink = gst_element_factory_make ("xvimagesink", NULL);
+
+    if (!m_videoSink)
+        m_videoSink = gst_element_factory_make ("ximagesink", NULL);
+
+    if (m_videoSink) {
+        // Check if the xv sink is usable
+        if (gst_element_set_state(m_videoSink, GST_STATE_READY) != GST_STATE_CHANGE_SUCCESS) {
+            gst_object_unref(GST_OBJECT(m_videoSink));
+            m_videoSink = 0;
+        } else {
+            gst_element_set_state(m_videoSink, GST_STATE_NULL);
+            g_object_set(G_OBJECT(m_videoSink), "force-aspect-ratio", 1, (const char*)NULL);
+            qt_gst_object_ref_sink(GST_OBJECT (m_videoSink)); //Take ownership
+        }
+    }
 }
 
 QGstreamerVideoWidgetControl::~QGstreamerVideoWidgetControl()
@@ -105,38 +121,17 @@ QGstreamerVideoWidgetControl::~QGstreamerVideoWidgetControl()
 
 void QGstreamerVideoWidgetControl::createVideoWidget()
 {
-    if (m_widget)
+    if (!m_videoSink || m_widget)
         return;
 
     m_widget = new QGstreamerVideoWidget;
 
     m_widget->installEventFilter(this);
     m_windowId = m_widget->winId();
-
-    m_videoSink = gst_element_factory_make ("xvimagesink", NULL);
-    if (m_videoSink) {
-        // Check if the xv sink is usable
-        if (gst_element_set_state(m_videoSink, GST_STATE_READY) != GST_STATE_CHANGE_SUCCESS) {
-            gst_object_unref(GST_OBJECT(m_videoSink));
-            m_videoSink = 0;
-        } else {
-            gst_element_set_state(m_videoSink, GST_STATE_NULL);
-
-            g_object_set(G_OBJECT(m_videoSink), "force-aspect-ratio", 1, (const char*)NULL);
-        }
-    }
-
-    if (!m_videoSink)
-        m_videoSink = gst_element_factory_make ("ximagesink", NULL);
-
-    qt_gst_object_ref_sink(GST_OBJECT (m_videoSink)); //Take ownership
-
-
 }
 
 GstElement *QGstreamerVideoWidgetControl::videoSink()
 {
-    createVideoWidget();
     return m_videoSink;
 }
 

src/plugins/gstreamer/camerabin/camerabinservice.cpp

@@ -121,9 +121,23 @@ CameraBinService::CameraBinService(GstElementFactory *sourceFactory, QObject *pa
 #else
     m_videoWindow = new QGstreamerVideoWindow(this);
 #endif
+    // If the GStreamer sink element is not available (xvimagesink), don't provide
+    // the video window control since it won't work anyway.
+    if (!m_videoWindow->videoSink()) {
+        delete m_videoWindow;
+        m_videoWindow = 0;
+    }
 
 #if defined(HAVE_WIDGETS)
     m_videoWidgetControl = new QGstreamerVideoWidgetControl(this);
+
+    // If the GStreamer sink element is not available (xvimagesink or ximagesink), don't provide
+    // the video widget control since it won't work anyway.
+    // QVideoWidget will fall back to QVideoRendererControl in that case.
+    if (!m_videoWidgetControl->videoSink()) {
+        delete m_videoWidgetControl;
+        m_videoWidgetControl = 0;
+    }
 #endif
 
     m_audioInputSelector = new QGstreamerAudioInputSelector(this);

src/plugins/gstreamer/camerabin/camerabinservice.h

@@ -48,6 +48,7 @@ class CameraBinControl;
 class QGstreamerMessage;
 class QGstreamerBusHelper;
 class QGstreamerVideoRenderer;
+class QGstreamerVideoWindow;
 class QGstreamerVideoWidgetControl;
 class QGstreamerElementFactory;
 class CameraBinMetaData;
@@ -79,7 +80,7 @@ private:
     QMediaControl *m_videoOutput;
 
     QMediaControl *m_videoRenderer;
-    QMediaControl *m_videoWindow;
+    QGstreamerVideoWindow *m_videoWindow;
 #if defined(HAVE_WIDGETS)
     QGstreamerVideoWidgetControl *m_videoWidgetControl;
 #endif

src/plugins/gstreamer/mediacapture/qgstreamercaptureservice.cpp

@@ -102,10 +102,25 @@ QGstreamerCaptureService::QGstreamerCaptureService(const QString &service, QObje
             m_videoInput->setDevice(m_videoInputDevice->deviceName(m_videoInputDevice->selectedDevice()));
 
         m_videoRenderer = new QGstreamerVideoRenderer(this);
+
         m_videoWindow = new QGstreamerVideoWindow(this);
+        // If the GStreamer sink element is not available (xvimagesink), don't provide
+        // the video window control since it won't work anyway.
+        if (!m_videoWindow->videoSink()) {
+            delete m_videoWindow;
+            m_videoWindow = 0;
+        }
 
 #if defined(HAVE_WIDGETS)
         m_videoWidgetControl = new QGstreamerVideoWidgetControl(this);
+
+        // If the GStreamer sink element is not available (xvimagesink or ximagesink), don't provide
+        // the video widget control since it won't work anyway.
+        // QVideoWidget will fall back to QVideoRendererControl in that case.
+        if (!m_videoWidgetControl->videoSink()) {
+            delete m_videoWidgetControl;
+            m_videoWidgetControl = 0;
+        }
 #endif
         m_imageCaptureControl = new QGstreamerImageCaptureControl(m_captureSession);
     }

src/plugins/gstreamer/mediacapture/qgstreamercaptureservice.h

@@ -48,6 +48,7 @@ class QGstreamerCameraControl;
 class QGstreamerMessage;
 class QGstreamerBusHelper;
 class QGstreamerVideoRenderer;
+class QGstreamerVideoWindow;
 class QGstreamerVideoWidgetControl;
 class QGstreamerElementFactory;
 class QGstreamerCaptureMetaDataControl;
@@ -81,9 +82,9 @@ private:
     QMediaControl *m_videoOutput;
 
     QGstreamerVideoRenderer *m_videoRenderer;
-    QMediaControl *m_videoWindow;
+    QGstreamerVideoWindow *m_videoWindow;
 #if defined(HAVE_WIDGETS)
-    QMediaControl *m_videoWidgetControl;
+    QGstreamerVideoWidgetControl *m_videoWidgetControl;
 #endif
     QGstreamerImageCaptureControl *m_imageCaptureControl;
 };

src/plugins/gstreamer/mediaplayer/qgstreamerplayerservice.cpp

@@ -91,9 +91,23 @@ QGstreamerPlayerService::QGstreamerPlayerService(QObject *parent):
 #else
     m_videoWindow = new QGstreamerVideoWindow(this);
 #endif
+    // If the GStreamer sink element is not available (xvimagesink), don't provide
+    // the video window control since it won't work anyway.
+    if (!m_videoWindow->videoSink()) {
+        delete m_videoWindow;
+        m_videoWindow = 0;
+    }
 
 #if defined(HAVE_WIDGETS)
     m_videoWidget = new QGstreamerVideoWidgetControl(this);
+
+    // If the GStreamer sink element is not available (xvimagesink or ximagesink), don't provide
+    // the video widget control since it won't work anyway.
+    // QVideoWidget will fall back to QVideoRendererControl in that case.
+    if (!m_videoWidget->videoSink()) {
+        delete m_videoWidget;
+        m_videoWidget = 0;
+    }
 #endif
 }
 

src/plugins/gstreamer/mediaplayer/qgstreamerplayerservice.h

@@ -50,6 +50,7 @@ class QGstreamerPlayerSession;
 class QGstreamerMetaDataProvider;
 class QGstreamerStreamsControl;
 class QGstreamerVideoRenderer;
+class QGstreamerVideoWindow;
 class QGstreamerVideoWidgetControl;
 class QGStreamerAvailabilityControl;
 
@@ -72,9 +73,9 @@ private:
 
     QMediaControl *m_videoOutput;
     QMediaControl *m_videoRenderer;
-    QMediaControl *m_videoWindow;
+    QGstreamerVideoWindow *m_videoWindow;
 #if defined(HAVE_WIDGETS)
-    QMediaControl *m_videoWidget;
+    QGstreamerVideoWidgetControl *m_videoWidget;
 #endif
 
     void increaseVideoRef();