From f1baf1a739b918216c14cd0ffb055f76a6e60a9b Mon Sep 17 00:00:00 2001
From: Thibault Saunier <tsaunier@igalia.com>
Date: Fri, 23 Nov 2018 11:22:03 -0300
Subject: [PATCH] effect: Create ghost pads ourself

As we can have effects with several pads and the default ghosting
doesn't allow that.

This way we also filter the pads to ghost to match our track type.
---
 ges/ges-effect.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 56 insertions(+), 4 deletions(-)

diff --git a/ges/ges-effect.c b/ges/ges-effect.c
index d9c31d7..84ef696 100644
--- a/ges/ges-effect.c
+++ b/ges/ges-effect.c
@@ -239,11 +239,45 @@ ges_effect_finalize (GObject * object)
   G_OBJECT_CLASS (ges_effect_parent_class)->finalize (object);
 }
 
+static void
+ghost_compatible_pads (GstElement * bin, GstElement * child,
+    GstCaps * valid_caps, gint * n_src, gint * n_sink)
+{
+  GList *tmp;
+
+  for (tmp = child->pads; tmp; tmp = tmp->next) {
+    GstCaps *caps;
+    GstPad *pad = tmp->data;
+
+    if (GST_PAD_PEER (pad))
+      continue;
+
+    caps = gst_pad_query_caps (pad, NULL);
+
+    if (gst_caps_can_intersect (caps, valid_caps)) {
+      gchar *name =
+          g_strdup_printf ("%s_%d", GST_PAD_IS_SINK (pad) ? "sink" : "src",
+          GST_PAD_IS_SINK (pad) ? *n_sink++ : *n_src++);
+
+      GST_DEBUG_OBJECT (bin, "Ghosting pad: %" GST_PTR_FORMAT, pad);
+      gst_element_add_pad (GST_ELEMENT (bin), gst_ghost_pad_new (name, pad));
+      g_free (name);
+    } else {
+      GST_DEBUG_OBJECT (pad, "Can't ghost pad %" GST_PTR_FORMAT, caps);
+    }
+
+    gst_caps_unref (caps);
+  }
+}
+
 static GstElement *
 ges_effect_create_element (GESTrackElement * object)
 {
+  GList *tmp;
   GstElement *effect;
   gchar *bin_desc;
+  GstCaps *valid_caps;
+  gint n_src = 0, n_sink = 0;
 
   GError *error = NULL;
   GESEffect *self = GES_EFFECT (object);
@@ -256,29 +290,47 @@ ges_effect_create_element (GESTrackElement * object)
     bin_desc = g_strconcat ("videoconvert name=pre_video_convert ! ",
         self->priv->bin_description, " ! videoconvert name=post_video_convert",
         NULL);
+    valid_caps = gst_caps_from_string ("video/x-raw(ANY)");
   } else if (type == GES_TRACK_TYPE_AUDIO) {
     bin_desc =
         g_strconcat ("audioconvert ! audioresample !",
         self->priv->bin_description, NULL);
+    valid_caps = gst_caps_from_string ("audio/x-raw(ANY)");
   } else {
     g_assert_not_reached ();
   }
 
-  effect = gst_parse_bin_from_description (bin_desc, TRUE, &error);
-
+  effect = gst_parse_bin_from_description (bin_desc, FALSE, &error);
   g_free (bin_desc);
-
   if (error != NULL) {
     GST_ERROR ("An error occured while creating the GstElement: %s",
         error->message);
     g_error_free (error);
-    return NULL;
+    goto fail;
+  }
+
+  for (tmp = GST_BIN_CHILDREN (effect); tmp; tmp = tmp->next) {
+    ghost_compatible_pads (effect, tmp->data, valid_caps, &n_src, &n_sink);
+
+    if (n_src > 1) {
+      GST_ERROR ("More than 1 source pad in the effect, that is not possible");
+
+      goto fail;
+    }
   }
 
   ges_track_element_add_children_props (object, effect, NULL,
       blacklisted_factories, NULL);
 
+done:
+  gst_clear_caps (&valid_caps);
+
   return effect;
+
+fail:
+  gst_clear_object (&effect);
+
+  goto done;
 }
 
 /**
-- 
2.7.4