+ * gst_element_factory_get_metadata_keys:
+ * @factory: a #GstElementFactory
+ *
+ * Get the available keys for the metadata on @factory.
+ *
+ * Returns: (transfer full) (element-type utf8) (array zero-terminated=1):
+ * a %NULL-terminated array of key strings, or %NULL when there is no
+ * metadata. Free with g_strfreev() when no longer needed.
+ */
+gchar **
+gst_element_factory_get_metadata_keys (GstElementFactory * factory)
+{
+ GstStructure *metadata;
+ gchar **arr;
+ gint i, num;
+
+ g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+ metadata = (GstStructure *) factory->metadata;
+ if (metadata == NULL)
+ return NULL;
+
+ num = gst_structure_n_fields (metadata);
+ if (num == 0)
+ return NULL;
+
+ arr = g_new (gchar *, num + 1);
+ for (i = 0; i < num; ++i) {
+ arr[i] = g_strdup (gst_structure_nth_field_name (metadata, i));
+ }
+ arr[i] = NULL;
+ return arr;
+}
+
+/**