--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/gst/gstelementfactory.c	Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,781 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *                    2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
+ *
+ * gstelementfactory.c: GstElementFactory object, support routines
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:gstelementfactory
+ * @short_description: Create GstElements from a factory
+ * @see_also: #GstElement, #GstPlugin, #GstPluginFeature, #GstPadTemplate.
+ *
+ * #GstElementFactory is used to create instances of elements. A
+ * GstElementfactory can be added to a #GstPlugin as it is also a
+ * #GstPluginFeature.
+ *
+ * Use the gst_element_factory_find() and gst_element_factory_create()
+ * functions to create element instances or use gst_element_factory_make() as a
+ * convenient shortcut.
+ *
+ * The following code example shows you how to create a GstFileSrc element.
+ *
+ * <example>
+ * <title>Using an element factory</title>
+ * <programlisting language="c">
+ *   #include &lt;gst/gst.h&gt;
+ *   GstElement *src;
+ *   GstElementFactory *srcfactory;
+ *   gst_init(&amp;argc,&amp;argv);
+ *   srcfactory = gst_element_factory_find("filesrc");
+ *   g_return_if_fail(srcfactory != NULL);
+ *   src = gst_element_factory_create(srcfactory,"src");
+ *   g_return_if_fail(src != NULL);
+ *   ...
+ * </programlisting>
+ * </example>
+ *
+ * Last reviewed on 2005-11-23 (0.9.5)
+ */
+
+#include "gst_private.h"
+
+#include "gstelement.h"
+#include "gstinfo.h"
+#include "gsturi.h"
+#include "gstregistry.h"
+
+#include "glib-compat-private.h"
+
+GST_DEBUG_CATEGORY_STATIC (element_factory_debug);
+#define GST_CAT_DEFAULT element_factory_debug
+
+static void gst_element_factory_class_init (GstElementFactoryClass * klass);
+static void gst_element_factory_init (GstElementFactory * factory);
+static void gst_element_factory_finalize (GObject * object);
+void __gst_element_details_clear (GstElementDetails * dp);
+static void gst_element_factory_cleanup (GstElementFactory * factory);
+
+static GstPluginFeatureClass *parent_class = NULL;
+
+/* static guint gst_element_factory_signals[LAST_SIGNAL] = { 0 }; */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GType
+gst_element_factory_get_type (void)
+{
+  static GType elementfactory_type = 0;
+
+  if (G_UNLIKELY (elementfactory_type == 0)) {
+    static const GTypeInfo elementfactory_info = {
+      sizeof (GstElementFactoryClass),
+      NULL,
+      NULL,
+      (GClassInitFunc) gst_element_factory_class_init,
+      NULL,
+      NULL,
+      sizeof (GstElementFactory),
+      0,
+      (GInstanceInitFunc) gst_element_factory_init,
+      NULL
+    };
+
+    elementfactory_type = g_type_register_static (GST_TYPE_PLUGIN_FEATURE,
+        "GstElementFactory", &elementfactory_info, 0);
+    GST_DEBUG_CATEGORY_INIT (element_factory_debug, "GST_ELEMENT_FACTORY",
+        GST_DEBUG_BOLD | GST_DEBUG_FG_WHITE | GST_DEBUG_BG_RED,
+        "element factories keep information about installed elements");
+  }
+  return elementfactory_type;
+}
+static void
+gst_element_factory_class_init (GstElementFactoryClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstObjectClass *gstobject_class;
+  GstPluginFeatureClass *gstpluginfeature_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstobject_class = (GstObjectClass *) klass;
+  gstpluginfeature_class = (GstPluginFeatureClass *) klass;
+
+  parent_class = g_type_class_peek_parent (klass);
+
+  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_element_factory_finalize);
+}
+
+static void
+gst_element_factory_init (GstElementFactory * factory)
+{
+  factory->staticpadtemplates = NULL;
+  factory->numpadtemplates = 0;
+
+  factory->uri_type = GST_URI_UNKNOWN;
+  factory->uri_protocols = NULL;
+
+  factory->interfaces = NULL;
+}
+
+static void
+gst_element_factory_finalize (GObject * object)
+{
+  GstElementFactory *factory = GST_ELEMENT_FACTORY (object);
+
+  gst_element_factory_cleanup (factory);
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+/**
+ * gst_element_factory_find:
+ * @name: name of factory to find
+ *
+ * Search for an element factory of the given name. Refs the returned
+ * element factory; caller is responsible for unreffing.
+ *
+ * Returns: #GstElementFactory if found, NULL otherwise
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstElementFactory *
+gst_element_factory_find (const gchar * name)
+{
+  GstPluginFeature *feature;
+
+  g_return_val_if_fail (name != NULL, NULL);
+
+  feature = gst_registry_find_feature (gst_registry_get_default (), name,
+      GST_TYPE_ELEMENT_FACTORY);
+  if (feature)
+    return GST_ELEMENT_FACTORY (feature);
+
+  /* this isn't an error, for instance when you query if an element factory is
+   * present */
+  GST_LOG ("no such element factory \"%s\"", name);
+  return NULL;
+}
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+__gst_element_details_clear (GstElementDetails * dp)
+{
+  g_free (dp->longname);
+  g_free (dp->klass);
+  g_free (dp->description);
+  g_free (dp->author);
+  memset (dp, 0, sizeof (GstElementDetails));
+}
+
+#define VALIDATE_SET(__dest, __src, __entry)                            \
+G_STMT_START {                                                          \
+  if (g_utf8_validate (__src->__entry, -1, NULL)) {                     \
+    __dest->__entry = g_strdup (__src->__entry);                        \
+  } else {                                                              \
+    g_warning ("Invalid UTF-8 in " G_STRINGIFY (__entry) ": %s",        \
+        __src->__entry);                                                \
+    __dest->__entry = g_strdup ("[ERROR: invalid UTF-8]");              \
+  }                                                                     \
+} G_STMT_END
+
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+void
+__gst_element_details_set (GstElementDetails * dest,
+    const GstElementDetails * src)
+{
+  VALIDATE_SET (dest, src, longname);
+  VALIDATE_SET (dest, src, klass);
+  VALIDATE_SET (dest, src, description);
+  VALIDATE_SET (dest, src, author);
+}
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+__gst_element_details_copy (GstElementDetails * dest,
+    const GstElementDetails * src)
+{
+  __gst_element_details_clear (dest);
+  __gst_element_details_set (dest, src);
+}
+
+static void
+gst_element_factory_cleanup (GstElementFactory * factory)
+{
+  GList *item;
+
+  __gst_element_details_clear (&factory->details);
+  if (factory->type) {
+    g_type_class_unref (g_type_class_peek (factory->type));
+    factory->type = 0;
+  }
+
+  for (item = factory->staticpadtemplates; item; item = item->next) {
+    GstStaticPadTemplate *templ = item->data;
+    GstCaps *caps = (GstCaps *) & (templ->static_caps);
+
+    g_free ((gchar *) templ->static_caps.string);
+
+    /* FIXME: this is not threadsafe */
+    if (caps->refcount == 1) {
+      GstStructure *structure;
+      guint i;
+
+      for (i = 0; i < caps->structs->len; i++) {
+        structure = (GstStructure *) gst_caps_get_structure (caps, i);
+        gst_structure_set_parent_refcount (structure, NULL);
+        gst_structure_free (structure);
+      }
+      g_ptr_array_free (caps->structs, TRUE);
+      caps->refcount = 0;
+    }
+    g_free (templ);
+  }
+  g_list_free (factory->staticpadtemplates);
+  factory->staticpadtemplates = NULL;
+  factory->numpadtemplates = 0;
+  factory->uri_type = GST_URI_UNKNOWN;
+  if (factory->uri_protocols) {
+    g_strfreev (factory->uri_protocols);
+    factory->uri_protocols = NULL;
+  }
+
+  g_list_foreach (factory->interfaces, (GFunc) g_free, NULL);
+  g_list_free (factory->interfaces);
+  factory->interfaces = NULL;
+}
+
+/**
+ * gst_element_register:
+ * @plugin: #GstPlugin to register the element with, or NULL for a static
+ * element (note that passing NULL only works in GStreamer 0.10.13 and later)
+ * @name: name of elements of this type
+ * @rank: rank of element (higher rank means more importance when autoplugging)
+ * @type: GType of element to register
+ *
+ * Create a new elementfactory capable of instantiating objects of the
+ * @type and add the factory to @plugin.
+ *
+ * Returns: TRUE, if the registering succeeded, FALSE on error
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_element_register (GstPlugin * plugin, const gchar * name, guint rank,
+    GType type)
+{
+  GstElementFactory *factory;
+  GType *interfaces;
+  guint n_interfaces, i;
+  GstElementClass *klass;
+  GList *item;
+
+  g_return_val_if_fail (name != NULL, FALSE);
+  g_return_val_if_fail (g_type_is_a (type, GST_TYPE_ELEMENT), FALSE);
+
+  factory = GST_ELEMENT_FACTORY (g_object_new (GST_TYPE_ELEMENT_FACTORY, NULL));
+  gst_plugin_feature_set_name (GST_PLUGIN_FEATURE (factory), name);
+  GST_LOG_OBJECT (factory, "Created new elementfactory for type %s",
+      g_type_name (type));
+
+  klass = GST_ELEMENT_CLASS (g_type_class_ref (type));
+  if ((klass->details.longname == NULL) ||
+      (klass->details.klass == NULL) || (klass->details.author == NULL))
+    goto detailserror;
+
+  factory->type = type;
+  __gst_element_details_copy (&factory->details, &klass->details);
+  for (item = klass->padtemplates; item; item = item->next) {
+    GstPadTemplate *templ = item->data;
+    GstStaticPadTemplate *newt;
+
+    newt = g_new0 (GstStaticPadTemplate, 1);
+    newt->name_template = g_intern_string (templ->name_template);
+    newt->direction = templ->direction;
+    newt->presence = templ->presence;
+    newt->static_caps.string = gst_caps_to_string (templ->caps);
+    factory->staticpadtemplates =
+        g_list_append (factory->staticpadtemplates, newt);
+  }
+  factory->numpadtemplates = klass->numpadtemplates;
+  klass->elementfactory = factory;
+
+  /* special stuff for URI handling */
+  if (g_type_is_a (type, GST_TYPE_URI_HANDLER)) {
+    GstURIHandlerInterface *iface = (GstURIHandlerInterface *)
+        g_type_interface_peek (klass, GST_TYPE_URI_HANDLER);
+
+    if (!iface || (!iface->get_type && !iface->get_type_full) ||
+        (!iface->get_protocols && !iface->get_protocols_full))
+      goto urierror;
+    if (iface->get_type)
+      factory->uri_type = iface->get_type ();
+    else if (iface->get_type_full)
+      factory->uri_type = iface->get_type_full (factory->type);
+    if (!GST_URI_TYPE_IS_VALID (factory->uri_type))
+      goto urierror;
+    if (iface->get_protocols)
+      factory->uri_protocols = g_strdupv (iface->get_protocols ());
+    else if (iface->get_protocols_full)
+      factory->uri_protocols = iface->get_protocols_full (factory->type);
+    if (!factory->uri_protocols)
+      goto urierror;
+  }
+
+  interfaces = g_type_interfaces (type, &n_interfaces);
+  for (i = 0; i < n_interfaces; i++) {
+    __gst_element_factory_add_interface (factory, g_type_name (interfaces[i]));
+  }
+  g_free (interfaces);
+
+  if (plugin && plugin->desc.name) {
+    GST_PLUGIN_FEATURE (factory)->plugin_name = plugin->desc.name;
+  } else {
+    GST_PLUGIN_FEATURE (factory)->plugin_name = "NULL";
+  }
+  gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE (factory), rank);
+  GST_PLUGIN_FEATURE (factory)->loaded = TRUE;
+
+  gst_registry_add_feature (gst_registry_get_default (),
+      GST_PLUGIN_FEATURE (factory));
+
+  return TRUE;
+
+  /* ERRORS */
+urierror:
+  {
+    GST_WARNING_OBJECT (factory, "error with uri handler!");
+    gst_element_factory_cleanup (factory);
+    return FALSE;
+  }
+
+detailserror:
+  {
+    GST_WARNING_OBJECT (factory,
+        "The GstElementDetails don't seem to have been set properly");
+    gst_element_factory_cleanup (factory);
+    return FALSE;
+  }
+}
+
+/**
+ * gst_element_factory_create:
+ * @factory: factory to instantiate
+ * @name: name of new element
+ *
+ * Create a new element of the type defined by the given elementfactory.
+ * It will be given the name supplied, since all elements require a name as
+ * their first argument.
+ *
+ * Returns: new #GstElement or NULL if the element couldn't be created
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstElement *
+gst_element_factory_create (GstElementFactory * factory, const gchar * name)
+{
+  GstElement *element;
+  GstElementClass *oclass;
+  GstElementFactory *newfactory;
+
+  g_return_val_if_fail (factory != NULL, NULL);
+
+  newfactory =
+      GST_ELEMENT_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE
+          (factory)));
+
+  if (newfactory == NULL)
+    goto load_failed;
+
+  factory = newfactory;
+
+  if (name)
+    GST_INFO ("creating element \"%s\" named \"%s\"",
+        GST_PLUGIN_FEATURE_NAME (factory), GST_STR_NULL (name));
+  else
+    GST_INFO ("creating element \"%s\"", GST_PLUGIN_FEATURE_NAME (factory));
+
+  if (factory->type == 0)
+    goto no_type;
+
+  /* create an instance of the element, cast so we don't assert on NULL */
+  element = GST_ELEMENT_CAST (g_object_new (factory->type, NULL));
+  if (G_UNLIKELY (element == NULL))
+    goto no_element;
+
+  /* fill in the pointer to the factory in the element class. The
+   * class will not be unreffed currently. 
+   * FIXME: This isn't safe and may leak a refcount on the factory if 2 threads
+   * create the first instance of an element at the same moment */
+  oclass = GST_ELEMENT_GET_CLASS (element);
+  if (G_UNLIKELY (oclass->elementfactory == NULL))
+    oclass->elementfactory = factory;
+  else
+    gst_object_unref (factory);
+
+  if (name)
+    gst_object_set_name (GST_OBJECT (element), name);
+
+  GST_DEBUG ("created element \"%s\"", GST_PLUGIN_FEATURE_NAME (factory));
+
+  return element;
+
+  /* ERRORS */
+load_failed:
+  {
+    GST_WARNING_OBJECT (factory, "loading plugin returned NULL!");
+    return NULL;
+  }
+no_type:
+  {
+    GST_WARNING_OBJECT (factory, "factory has no type");
+    gst_object_unref (factory);
+    return NULL;
+  }
+no_element:
+  {
+    GST_WARNING_OBJECT (factory, "could not create element");
+    gst_object_unref (factory);
+    return NULL;
+  }
+}
+
+/**
+ * gst_element_factory_make:
+ * @factoryname: a named factory to instantiate
+ * @name: name of new element
+ *
+ * Create a new element of the type defined by the given element factory.
+ * If name is NULL, then the element will receive a guaranteed unique name,
+ * consisting of the element factory name and a number.
+ * If name is given, it will be given the name supplied.
+ *
+ * Returns: new #GstElement or NULL if unable to create element
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstElement *
+gst_element_factory_make (const gchar * factoryname, const gchar * name)
+{
+  GstElementFactory *factory;
+  GstElement *element;
+
+  g_return_val_if_fail (factoryname != NULL, NULL);
+
+  GST_LOG ("gstelementfactory: make \"%s\" \"%s\"",
+      factoryname, GST_STR_NULL (name));
+
+  factory = gst_element_factory_find (factoryname);
+  if (factory == NULL)
+    goto no_factory;
+
+  GST_LOG_OBJECT (factory, "found factory %p", factory);
+  element = gst_element_factory_create (factory, name);
+  gst_object_unref (factory);
+  if (element == NULL)
+    goto create_failed;
+
+  return element;
+
+  /* ERRORS */
+no_factory:
+  {
+    GST_INFO ("no such element factory \"%s\"!", factoryname);
+    return NULL;
+  }
+create_failed:
+  {
+    GST_INFO_OBJECT (factory, "couldn't create instance!");
+    return NULL;
+  }
+}
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+__gst_element_factory_add_static_pad_template (GstElementFactory * factory,
+    GstStaticPadTemplate * templ)
+{
+  g_return_if_fail (factory != NULL);
+  g_return_if_fail (templ != NULL);
+
+  factory->staticpadtemplates =
+      g_list_append (factory->staticpadtemplates, templ);
+  factory->numpadtemplates++;
+}
+
+/**
+ * gst_element_factory_get_element_type:
+ * @factory: factory to get managed #GType from
+ *
+ * Get the #GType for elements managed by this factory. The type can
+ * only be retrieved if the element factory is loaded, which can be
+ * assured with gst_plugin_feature_load().
+ *
+ * Returns: the #GType for elements managed by this factory or 0 if
+ * the factory is not loaded.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GType
+gst_element_factory_get_element_type (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), 0);
+
+  return factory->type;
+}
+
+/**
+ * gst_element_factory_get_longname:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the longname for this factory
+ *
+ * Returns: the longname
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_element_factory_get_longname (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+  return factory->details.longname;
+}
+
+/**
+ * gst_element_factory_get_klass:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the class for this factory.
+ *
+ * Returns: the class
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_element_factory_get_klass (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+  return factory->details.klass;
+}
+
+/**
+ * gst_element_factory_get_description:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the description for this factory.
+ *
+ * Returns: the description
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_element_factory_get_description (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+  return factory->details.description;
+}
+
+/**
+ * gst_element_factory_get_author:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the author for this factory.
+ *
+ * Returns: the author
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_element_factory_get_author (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+  return factory->details.author;
+}
+
+/**
+ * gst_element_factory_get_num_pad_templates:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the number of pad_templates in this factory.
+ *
+ * Returns: the number of pad_templates
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+guint
+gst_element_factory_get_num_pad_templates (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), 0);
+
+  return factory->numpadtemplates;
+}
+
+/**
+ * __gst_element_factory_add_interface:
+ * @elementfactory: The elementfactory to add the interface to
+ * @interfacename: Name of the interface
+ *
+ * Adds the given interfacename to the list of implemented interfaces of the
+ * element.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+__gst_element_factory_add_interface (GstElementFactory * elementfactory,
+    const gchar * interfacename)
+{
+  g_return_if_fail (GST_IS_ELEMENT_FACTORY (elementfactory));
+  g_return_if_fail (interfacename != NULL);
+  g_return_if_fail (interfacename[0] != '\0');  /* no empty string */
+
+  elementfactory->interfaces =
+      g_list_prepend (elementfactory->interfaces, g_strdup (interfacename));
+}
+
+/**
+ * gst_element_factory_get_static_pad_templates:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the #GList of #GstStaticPadTemplate for this factory.
+ *
+ * Returns: the padtemplates
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN GList *
+gst_element_factory_get_static_pad_templates (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+  return factory->staticpadtemplates;
+}
+
+/**
+ * gst_element_factory_get_uri_type:
+ * @factory: a #GstElementFactory
+ *
+ * Gets the type of URIs the element supports or GST_URI_UNKNOWN if none.
+ *
+ * Returns: type of URIs this element supports
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gint
+gst_element_factory_get_uri_type (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), GST_URI_UNKNOWN);
+
+  return factory->uri_type;
+}
+
+/**
+ * gst_element_factory_get_uri_protocols:
+ * @factory: a #GstElementFactory
+ *
+ * Gets a NULL-terminated array of protocols this element supports or NULL if
+ * no protocols are supported. You may not change the contents of the returned
+ * array, as it is still owned by the element factory. Use g_strdupv() to
+ * make a copy of the protocol string array if you need to.
+ *
+ * Returns: the supported protocols or NULL
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gchar **
+gst_element_factory_get_uri_protocols (GstElementFactory * factory)
+{
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), NULL);
+
+  return factory->uri_protocols;
+}
+
+/**
+ * gst_element_factory_has_interface:
+ * @factory: a #GstElementFactory
+ * @interfacename: an interface name
+ *
+ * Check if @factory implements the interface with name @interfacename.
+ *
+ * Returns: #TRUE when @factory implement the interface.
+ *
+ * Since: 0.10.14
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_element_factory_has_interface (GstElementFactory * factory,
+    const gchar * interfacename)
+{
+  GList *walk;
+
+  g_return_val_if_fail (GST_IS_ELEMENT_FACTORY (factory), FALSE);
+
+  for (walk = factory->interfaces; walk; walk = g_list_next (walk)) {
+    gchar *iname = (gchar *) walk->data;
+
+    if (!strcmp (iname, interfacename))
+      return TRUE;
+  }
+  return FALSE;
+}