video-transition: Use a SmartMixer as mixer

So that the frame position metas are parsed and taken into account

ges/ges-smart-video-mixer.c

@@ -67,10 +67,28 @@ destroy_pad (PadInfos * infos)
   g_slice_free (PadInfos, infos);
 }
 
+GstPad *
+ges_smart_mixer_get_mixer_pad (GESSmartMixer * self, GstPad ** mixerpad)
+{
+  PadInfos *info;
+  GstPad *sinkpad;
+
+  sinkpad = gst_element_get_request_pad (GST_ELEMENT (self), "sink_%u");
+
+  if (sinkpad == NULL)
+    return NULL;
+
+  info = g_hash_table_lookup (self->pads_infos, sinkpad);
+  *mixerpad = info->mixer_pad;
+
+  return sinkpad;
+}
+
 /* These metadata will get set by the upstream framepositionner element,
    added in the video sources' bin */
 static GstPadProbeReturn
-parse_metadata (GstPad * mixer_pad, GstPadProbeInfo * info, gpointer unused)
+parse_metadata (GstPad * mixer_pad, GstPadProbeInfo * info,
+    GESSmartMixer * self)
 {
   GstFramePositionnerMeta *meta;
 
@@ -83,7 +101,11 @@ parse_metadata (GstPad * mixer_pad, GstPadProbeInfo * info, gpointer unused)
     return GST_PAD_PROBE_OK;
   }
 
-  g_object_set (mixer_pad, "alpha", meta->alpha, "xpos", meta->posx, "ypos",
+  if (!self->no_alpha) {
+    g_object_set (mixer_pad, "alpha", meta->alpha, NULL);
+  }
+
+  g_object_set (mixer_pad, "xpos", meta->posx, "ypos",
       meta->posy, "zorder", meta->zorder, "width", meta->width,
       "height", meta->height, NULL);
 
@@ -142,7 +164,7 @@ _request_new_pad (GstElement * element, GstPadTemplate * templ,
 
   infos->probe_id =
       gst_pad_add_probe (infos->mixer_pad, GST_PAD_PROBE_TYPE_BUFFER,
-      (GstPadProbeCallback) parse_metadata, NULL, NULL);
+      (GstPadProbeCallback) parse_metadata, self, NULL);
 
   LOCK (self);
   g_hash_table_insert (self->pads_infos, ghost, infos);
@@ -245,7 +267,6 @@ GstElement *
 ges_smart_mixer_new (GESTrack * track)
 {
   GESSmartMixer *self = g_object_new (GES_TYPE_SMART_MIXER, NULL);
-  self->track = track;
 
   /* FIXME Make mixer smart and let it properly negotiate caps! */
   return GST_ELEMENT (self);

ges/ges-smart-video-mixer.h

@@ -54,13 +54,14 @@ struct _GESSmartMixer
   GMutex lock;
 
   GstCaps *caps;
-
-  GESTrack *track;
+  gboolean no_alpha;
 
   gpointer _ges_reserved[GES_PADDING];
 };
 
 GType         ges_smart_mixer_get_type (void) G_GNUC_CONST;
+GstPad *
+ges_smart_mixer_get_mixer_pad (GESSmartMixer *self, GstPad **mixerpad);
 GstElement*   ges_smart_mixer_new      (GESTrack *track);
 
 G_END_DECLS

ges/ges-video-transition.c

@@ -25,6 +25,7 @@
 
 #include <ges/ges.h>
 #include "ges-internal.h"
+#include "ges-smart-video-mixer.h"
 
 #include <gst/controller/gstdirectcontrolbinding.h>
 
@@ -311,9 +312,9 @@ ges_video_transition_create_element (GESTrackElement * object)
 
   gst_bin_add_many (GST_BIN (topbin), iconva, iconvb, oconv, NULL);
 
-  mixer = gst_element_factory_create (ges_get_compositor_factory (), NULL);
+  mixer = ges_smart_mixer_new (NULL);
   g_assert (mixer);
-  g_object_set (G_OBJECT (mixer), "background", 1, NULL);
+  GES_SMART_MIXER (mixer)->no_alpha = TRUE;
   gst_bin_add (GST_BIN (topbin), mixer);
 
   priv->mixer_sinka =
@@ -372,7 +373,7 @@ link_element_to_mixer_with_smpte (GstBin * bin, GstElement * element,
     GstElement * mixer, gint type, GstElement ** smpteref,
     GESVideoTransitionPrivate * priv)
 {
-  GstPad *srcpad, *sinkpad;
+  GstPad *srcpad, *sinkpad, *mixerpad;
   GstElement *smptealpha = gst_element_factory_make ("smptealpha", NULL);
 
   g_object_set (G_OBJECT (smptealpha),
@@ -388,11 +389,11 @@ link_element_to_mixer_with_smpte (GstBin * bin, GstElement * element,
   }
 
   srcpad = gst_element_get_static_pad (smptealpha, "src");
-  sinkpad = gst_element_get_request_pad (mixer, "sink_%u");
+  sinkpad = ges_smart_mixer_get_mixer_pad (GES_SMART_MIXER (mixer), &mixerpad);
   gst_pad_link_full (srcpad, sinkpad, GST_PAD_LINK_CHECK_NOTHING);
   gst_object_unref (srcpad);
 
-  return G_OBJECT (sinkpad);
+  return G_OBJECT (mixerpad);
 }
 
 static void