API: Add gst_message_{new,parse}_tag_full() to get/set the source pad

Fixes bug #582588.

docs/gst/gstreamer-sections.txt

@@ -1108,7 +1108,9 @@ gst_message_parse_warning
 gst_message_new_info
 gst_message_parse_info
 gst_message_new_tag
+gst_message_new_tag_full
 gst_message_parse_tag
+gst_message_parse_tag_full
 gst_message_new_buffering
 gst_message_parse_buffering
 gst_message_set_buffering_stats

gst/gstmessage.c

@@ -472,6 +472,39 @@ gst_message_new_tag (GstObject * src, GstTagList * tag_list)
   return message;
 }
 
+/**
+ * gst_message_new_tag_full:
+ * @src: The object originating the message.
+ * @pad: The originating pad for the tag.
+ * @tag_list: The tag list for the message.
+ *
+ * Create a new tag message. The message will take ownership of the tag list.
+ * The message is posted by elements that discovered a new taglist.
+ *
+ * Returns: The new tag message.
+ *
+ * Since: 0.10.24
+ *
+ * MT safe.
+ */
+GstMessage *
+gst_message_new_tag_full (GstObject * src, GstPad * pad, GstTagList * tag_list)
+{
+  GstMessage *message;
+  GstStructure *s;
+
+  g_return_val_if_fail (GST_IS_STRUCTURE (tag_list), NULL);
+  g_return_val_if_fail (pad == NULL || GST_IS_PAD (pad), NULL);
+
+  s = (GstStructure *) tag_list;
+  if (pad)
+    gst_structure_set (s, "source-pad", GST_TYPE_PAD, pad, NULL);
+
+  message = gst_message_new_custom (GST_MESSAGE_TAG, src, s);
+
+  return message;
+}
+
 /**
  * gst_message_new_buffering:
  * @src: The object originating the message.
@@ -970,11 +1003,57 @@ gst_message_get_structure (GstMessage * message)
 void
 gst_message_parse_tag (GstMessage * message, GstTagList ** tag_list)
 {
+  GstStructure *ret;
+
   g_return_if_fail (GST_IS_MESSAGE (message));
   g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_TAG);
   g_return_if_fail (tag_list != NULL);
 
-  *tag_list = (GstTagList *) gst_structure_copy (message->structure);
+  ret = gst_structure_copy (message->structure);
+  gst_structure_remove_field (ret, "source-pad");
+
+  *tag_list = (GstTagList *) ret;
+}
+
+/**
+ * gst_message_parse_tag_full:
+ * @message: A valid #GstMessage of type GST_MESSAGE_TAG.
+ * @pad: Location where the originating pad is stored, unref after usage
+ * @tag_list: Return location for the tag-list.
+ *
+ * Extracts the tag list from the GstMessage. The tag list returned in the
+ * output argument is a copy; the caller must free it when done.
+ *
+ * Since: 0.10.24
+ *
+ * MT safe.
+ */
+void
+gst_message_parse_tag_full (GstMessage * message, GstPad ** pad,
+    GstTagList ** tag_list)
+{
+  GstStructure *ret;
+
+  g_return_if_fail (GST_IS_MESSAGE (message));
+  g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_TAG);
+  g_return_if_fail (tag_list != NULL);
+
+  ret = gst_structure_copy (message->structure);
+
+  if (gst_structure_has_field (ret, "source-pad") && pad) {
+    const GValue *v;
+
+    v = gst_structure_get_value (ret, "source-pad");
+    if (v && G_VALUE_HOLDS (v, GST_TYPE_PAD))
+      *pad = g_value_dup_object (v);
+    else
+      *pad = NULL;
+  } else if (pad) {
+    *pad = NULL;
+  }
+  gst_structure_remove_field (ret, "source-pad");
+
+  *tag_list = (GstTagList *) ret;
 }
 
 /**

gst/gstmessage.h

@@ -360,7 +360,9 @@ void		gst_message_parse_info 		(GstMessage *message, GError **gerror, gchar **de
 
 /* TAG */
 GstMessage *	gst_message_new_tag		(GstObject * src, GstTagList * tag_list);
+GstMessage *	gst_message_new_tag_full	(GstObject * src, GstPad *pad, GstTagList * tag_list);
 void		gst_message_parse_tag		(GstMessage *message, GstTagList **tag_list);
+void		gst_message_parse_tag_full	(GstMessage *message, GstPad **pad, GstTagList **tag_list);
 
 /* BUFFERING */
 GstMessage *	gst_message_new_buffering	  (GstObject * src, gint percent);

gst/gstutils.c

@@ -3081,11 +3081,9 @@ gst_element_found_tags_for_pad (GstElement * element,
   g_return_if_fail (list != NULL);
 
   gst_pad_push_event (pad, gst_event_new_tag (gst_tag_list_copy (list)));
-  /* FIXME 0.11: Set the pad as source to make it possible to detect for
-   * which pad the tags are actually found.
-   */
+  /* FIXME 0.11: Set the pad as source. */
   gst_element_post_message (element,
-      gst_message_new_tag (GST_OBJECT (element), list));
+      gst_message_new_tag_full (GST_OBJECT (element), pad, list));
 }
 
 static void

win32/common/libgstbase.def

@@ -5,7 +5,6 @@ EXPORTS
 	gst_adapter_copy
 	gst_adapter_flush
 	gst_adapter_get_type
-	gst_adapter_masked_scan_uint32
 	gst_adapter_new
 	gst_adapter_peek
 	gst_adapter_prev_timestamp

win32/common/libgstreamer.def

@@ -490,6 +490,7 @@ EXPORTS
 	gst_message_new_stream_status
 	gst_message_new_structure_change
 	gst_message_new_tag
+	gst_message_new_tag_full
 	gst_message_new_warning
 	gst_message_parse_async_start
 	gst_message_parse_buffering
@@ -507,6 +508,7 @@ EXPORTS
 	gst_message_parse_stream_status
 	gst_message_parse_structure_change
 	gst_message_parse_tag
+	gst_message_parse_tag_full
 	gst_message_parse_warning
 	gst_message_set_buffering_stats
 	gst_message_set_seqnum