aggregator: Remove klass->sinkpads_type

This posed problems for the python bindings (and possibly others).

Instead, subclasses now use add_pad_template_with_gtype.

https://bugzilla.gnome.org/show_bug.cgi?id=789986

ext/gl/gstglbasemixer.c

@@ -270,7 +270,6 @@ gst_gl_base_mixer_class_init (GstGLBaseMixerClass * klass)
       GST_DEBUG_FUNCPTR (gst_gl_base_mixer_set_context);
   element_class->change_state = gst_gl_base_mixer_change_state;
 
-  agg_class->sinkpads_type = GST_TYPE_GL_BASE_MIXER_PAD;
   agg_class->sink_query = gst_gl_base_mixer_sink_query;
   agg_class->src_query = gst_gl_base_mixer_src_query;
   agg_class->src_activate = gst_gl_base_mixer_src_activate_mode;

ext/gl/gstglmixer.c

@@ -365,9 +365,9 @@ gst_gl_mixer_class_init (GstGLMixerClass * klass)
   gobject_class->set_property = gst_gl_mixer_set_property;
 
   gst_element_class_add_static_pad_template (element_class, &src_factory);
-  gst_element_class_add_static_pad_template (element_class, &sink_factory);
+  gst_element_class_add_static_pad_template_with_gtype (element_class,
+      &sink_factory, GST_TYPE_GL_MIXER_PAD);
 
-  agg_class->sinkpads_type = GST_TYPE_GL_MIXER_PAD;
   agg_class->sink_query = gst_gl_mixer_sink_query;
   agg_class->src_query = gst_gl_mixer_src_query;
   agg_class->stop = gst_gl_mixer_stop;

ext/gl/gstglstereomix.c

@@ -180,9 +180,9 @@ gst_gl_stereo_mix_class_init (GstGLStereoMixClass * klass)
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   gst_element_class_add_static_pad_template (element_class, &src_factory);
-  gst_element_class_add_static_pad_template (element_class, &sink_factory);
+  gst_element_class_add_static_pad_template_with_gtype (element_class,
+      &sink_factory, GST_TYPE_GL_STEREO_MIX_PAD);
 
-  agg_class->sinkpads_type = GST_TYPE_GL_STEREO_MIX_PAD;
   agg_class->stop = gst_gl_stereo_mix_stop;
   agg_class->start = gst_gl_stereo_mix_start;
   agg_class->src_query = gst_gl_stereo_mix_src_query;

ext/gl/gstglvideomixer.c

@@ -55,6 +55,14 @@
 #define GST_CAT_DEFAULT gst_gl_video_mixer_debug
 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
 
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink_%u",
+    GST_PAD_SINK,
+    GST_PAD_REQUEST,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE_WITH_FEATURES
+        (GST_CAPS_FEATURE_MEMORY_GL_MEMORY,
+            "RGBA"))
+    );
+
 #define GST_TYPE_GL_VIDEO_MIXER_BACKGROUND (gst_gl_video_mixer_background_get_type())
 static GType
 gst_gl_video_mixer_background_get_type (void)
@@ -862,6 +870,9 @@ gst_gl_video_mixer_class_init (GstGLVideoMixerClass * klass)
       "Filter/Effect/Video/Compositor", "OpenGL video_mixer",
       "Matthew Waters <matthew@centricular.com>");
 
+  gst_element_class_add_static_pad_template_with_gtype (element_class,
+      &sink_factory, GST_TYPE_GL_VIDEO_MIXER_PAD);
+
   g_object_class_install_property (gobject_class, PROP_BACKGROUND,
       g_param_spec_enum ("background", "Background", "Background type",
           GST_TYPE_GL_VIDEO_MIXER_BACKGROUND,
@@ -875,7 +886,6 @@ gst_gl_video_mixer_class_init (GstGLVideoMixerClass * klass)
 
   vagg_class->update_caps = _update_caps;
 
-  agg_class->sinkpads_type = GST_TYPE_GL_VIDEO_MIXER_PAD;
   agg_class->fixate_src_caps = _fixate_caps;
   agg_class->propose_allocation = gst_gl_video_mixer_propose_allocation;
 

gst-libs/gst/video/gstvideoaggregator.c

@@ -692,8 +692,6 @@ static gboolean
 gst_video_aggregator_default_negotiated_src_caps (GstAggregator * agg,
     GstCaps * caps)
 {
-  GstVideoAggregatorPadClass *vaggpad_klass = g_type_class_peek
-      (GST_AGGREGATOR_GET_CLASS (agg)->sinkpads_type);
   GstVideoAggregator *vagg = GST_VIDEO_AGGREGATOR (agg);
   gboolean at_least_one_alpha = FALSE;
   const GstVideoFormatInfo *finfo;
@@ -741,16 +739,17 @@ gst_video_aggregator_default_negotiated_src_caps (GstAggregator * agg,
     return FALSE;
   }
 
-  if (vaggpad_klass->set_info) {
   /* Then browse the sinks once more, setting or unsetting conversion if needed */
   for (l = GST_ELEMENT (vagg)->sinkpads; l; l = l->next) {
     GstVideoAggregatorPad *pad = GST_VIDEO_AGGREGATOR_PAD (l->data);
+    GstVideoAggregatorPadClass *vaggpad_klass =
+        GST_VIDEO_AGGREGATOR_PAD_GET_CLASS (pad);
 
-      if (!vaggpad_klass->set_info (pad, vagg, &pad->info, &vagg->info)) {
+    if (vaggpad_klass->set_info
+        && !vaggpad_klass->set_info (pad, vagg, &pad->info, &vagg->info)) {
       return FALSE;
     }
   }
-  }
 
   if (vagg->priv->current_caps == NULL ||
       gst_caps_is_equal (caps, vagg->priv->current_caps) == FALSE) {
@@ -1305,6 +1304,7 @@ clean_pad (GstElement * agg, GstPad * pad, gpointer user_data)
   GstVideoAggregatorPadClass *vaggpad_class =
       GST_VIDEO_AGGREGATOR_PAD_GET_CLASS (pad);
 
+  if (vaggpad_class->clean_frame)
     vaggpad_class->clean_frame (vpad, vagg);
 
   return TRUE;
@@ -1318,8 +1318,6 @@ gst_video_aggregator_do_aggregate (GstVideoAggregator * vagg,
   GstFlowReturn ret = GST_FLOW_OK;
   GstElementClass *klass = GST_ELEMENT_GET_CLASS (vagg);
   GstVideoAggregatorClass *vagg_klass = (GstVideoAggregatorClass *) klass;
-  GstVideoAggregatorPadClass *vaggpad_class = g_type_class_peek
-      (GST_AGGREGATOR_CLASS (klass)->sinkpads_type);
 
   g_assert (vagg_klass->aggregate_frames != NULL);
   g_assert (vagg_klass->get_output_buffer != NULL);
@@ -1345,9 +1343,7 @@ gst_video_aggregator_do_aggregate (GstVideoAggregator * vagg,
 
   ret = vagg_klass->aggregate_frames (vagg, *outbuf);
 
-  if (vaggpad_class->clean_frame) {
   gst_element_foreach_sink_pad (GST_ELEMENT_CAST (vagg), clean_pad, NULL);
-  }
 
   return ret;
 }
@@ -2189,7 +2185,6 @@ gst_video_aggregator_class_init (GstVideoAggregatorClass * klass)
   gstelement_class->release_pad =
       GST_DEBUG_FUNCPTR (gst_video_aggregator_release_pad);
 
-  agg_class->sinkpads_type = GST_TYPE_VIDEO_AGGREGATOR_PAD;
   agg_class->start = gst_video_aggregator_start;
   agg_class->stop = gst_video_aggregator_stop;
   agg_class->sink_query = gst_video_aggregator_sink_query;

gst/compositor/compositor.c

@@ -1223,7 +1223,6 @@ gst_compositor_class_init (GstCompositorClass * klass)
   gobject_class->get_property = gst_compositor_get_property;
   gobject_class->set_property = gst_compositor_set_property;
 
-  agg_class->sinkpads_type = GST_TYPE_COMPOSITOR_PAD;
   agg_class->sink_query = _sink_query;
   agg_class->fixate_src_caps = _fixate_caps;
   agg_class->negotiated_src_caps = _negotiated_caps;
@@ -1235,7 +1234,8 @@ gst_compositor_class_init (GstCompositorClass * klass)
           DEFAULT_BACKGROUND, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   gst_element_class_add_static_pad_template (gstelement_class, &src_factory);
-  gst_element_class_add_static_pad_template (gstelement_class, &sink_factory);
+  gst_element_class_add_static_pad_template_with_gtype (gstelement_class,
+      &sink_factory, GST_TYPE_COMPOSITOR_PAD);
 
   gst_element_class_set_static_metadata (gstelement_class, "Compositor",
       "Filter/Editor/Video/Compositor",