auto-sink: Ensure the IS_SINK flagclutter-gst-1.6

The ClutterGstAutoVideoSink sets its GST_ELEMENT_IS_SINK flag in its
init method. However, in contrast to the ClutterGstVideoSink, this class
is not based on GstBaseSink but on GstBin instead.

The problem is that GstBin automatically sets its GST_ELEMENT_IS_SINK
flag whenever a sink is added. It also automatically unsets it whenever
the last sink is removed from the bin.

Now, after the first video clip is finished and the pipeline leaves the
PLAYING state, the encapsulated ClutterGstVideoSink is removed from the
ClutterGstAutoVideoSink leaving it without any sinks and thus making it
lose its GST_ELEMENT_IS_SINK flag. Apparently this happens even before
the EOS signal is broadcast in the pipeline.

Interestingly, the ClutterGstAutoVideoSink does receive the EOS signal
and forwards it to its parent, the vbin of the playsink. But the vbin
ignores the signal because in bin_do_eos (gstbin.c) the is_eos check
fails. This check, in turn, fails because the bin_element_is_sink check
fails on its child, the ClutterGstAutoVideoSink (because its
GST_ELEMENT_IS_SINK flag isn't set anymore).

Bugzilla: https://bugzilla.gnome.org/show_bug.cgi?id=679611

1 files changed, 37 insertions, 0 deletions

diff --git a/clutter-gst/clutter-gst-auto-video-sink.c b/clutter-gst/clutter-gst-auto-video-sink.c
index a689280..bb83429 100644
--- a/clutter-gst/clutter-gst-auto-video-sink.c
+++ b/clutter-gst/clutter-gst-auto-video-sink.c
@@ -60,6 +60,9 @@ enum
 
 #define DEFAULT_TS_OFFSET           0
 
+static gboolean clutter_gst_auto_video_sink_add_func (GstBin * bin, GstElement * element);
+static gboolean clutter_gst_auto_video_sink_remove_func (GstBin * bin, GstElement * element);
+
 GST_BOILERPLATE (ClutterGstAutoVideoSink,
                  clutter_gst_auto_video_sink,
                  GstBin,
@@ -649,6 +652,35 @@ activate_failed:
   }
 }
 
+/*
+ * Call the base class implementation and make
+ * sure that the GST_ELEMENT_IS_SINK flag is still
+ * set afterwards.
+ */
+static gboolean
+clutter_gst_auto_video_sink_add_func (GstBin * bin, GstElement * element)
+{
+  gboolean result;
+
+  result = GST_BIN_CLASS (parent_class)->add_element (bin, element);
+  GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
+  return result;
+}
+
+/*
+ * Call the base class implementation and make
+ * sure that the GST_ELEMENT_IS_SINK flag is still
+ * set afterwards.
+ */
+static gboolean
+clutter_gst_auto_video_sink_remove_func (GstBin * bin, GstElement * element) {
+  gboolean result;
+
+  result = GST_BIN_CLASS (parent_class)->remove_element (bin, element);
+  GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
+  return result;
+}
+
 static void
 clutter_gst_auto_video_sink_dispose (GObject *object)
 {
@@ -768,6 +800,7 @@ clutter_gst_auto_video_sink_class_init (ClutterGstAutoVideoSinkClass *klass)
 {
   GObjectClass *oclass = G_OBJECT_CLASS (klass);
   GstElementClass *gstelement_class;
+  GstBinClass *gstbin_class;
   GParamSpec *pspec;
 
   oclass->dispose = clutter_gst_auto_video_sink_dispose;
@@ -799,6 +832,10 @@ clutter_gst_auto_video_sink_class_init (ClutterGstAutoVideoSinkClass *klass)
   gstelement_class = (GstElementClass *)klass;
   gstelement_class->change_state =
     GST_DEBUG_FUNCPTR (clutter_gst_auto_video_sink_change_state);
+
+  gstbin_class = (GstBinClass *)klass;
+  gstbin_class->add_element = GST_DEBUG_FUNCPTR (clutter_gst_auto_video_sink_add_func);
+  gstbin_class->remove_element = GST_DEBUG_FUNCPTR (clutter_gst_auto_video_sink_remove_func);
 }
 
 static void