--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/gst/gstplugin.c	Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,1134 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wtay@chello.be>
+ *
+ * gstplugin.c: Plugin subsystem for loading elements, types, and libs
+ *
+ * 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:gstplugin
+ * @short_description: Container for features loaded from a shared object module
+ * @see_also: #GstPluginFeature, #GstElementFactory
+ *
+ * GStreamer is extensible, so #GstElement instances can be loaded at runtime.
+ * A plugin system can provide one or more of the basic
+ * <application>GStreamer</application> #GstPluginFeature subclasses.
+ *
+ * A plugin should export a symbol <symbol>gst_plugin_desc</symbol> that is a
+ * struct of type #GstPluginDesc.
+ * the plugin loader will check the version of the core library the plugin was
+ * linked against and will create a new #GstPlugin. It will then call the
+ * #GstPluginInitFunc function that was provided in the
+ * <symbol>gst_plugin_desc</symbol>.
+ *
+ * Once you have a handle to a #GstPlugin (e.g. from the #GstRegistryPool), you
+ * can add any object that subclasses #GstPluginFeature.
+ *
+ * Use gst_plugin_find_feature() and gst_plugin_get_feature_list() to find
+ * features in a plugin.
+ *
+ * Usually plugins are always automaticlly loaded so you don't need to call
+ * gst_plugin_load() explicitly to bring it into memory. There are options to
+ * statically link plugins to an app or even use GStreamer without a plugin
+ * repository in which case gst_plugin_load() can be needed to bring the plugin
+ * into memory.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <glib/gstdio.h>
+#include <sys/types.h>
+#ifdef HAVE_DIRENT_H
+#include <dirent.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <signal.h>
+#include <errno.h>
+
+#include "gst_private.h"
+#include "glib-compat-private.h"
+
+#include <gst/gst.h>
+
+#ifdef __SYMBIAN32__
+#include <glib_global.h>
+#endif
+
+#define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING
+
+static guint _num_static_plugins;       /* 0    */
+static GstPluginDesc *_static_plugins;  /* NULL */
+static gboolean _gst_plugin_inited;
+
+/* static variables for segfault handling of plugin loading */
+static char *_gst_plugin_fault_handler_filename = NULL;
+
+#ifndef HAVE_WIN32
+static gboolean _gst_plugin_fault_handler_is_setup = FALSE;
+#endif
+
+/* list of valid licenses.
+ * One of these must be specified or the plugin won't be loaded
+ * Contact gstreamer-devel@lists.sourceforge.net if your license should be
+ * added.
+ *
+ * GPL: http://www.gnu.org/copyleft/gpl.html
+ * LGPL: http://www.gnu.org/copyleft/lesser.html
+ * QPL: http://www.trolltech.com/licenses/qpl.html
+ * MPL: http://www.opensource.org/licenses/mozilla1.1.php
+ * MIT/X11: http://www.opensource.org/licenses/mit-license.php
+ * 3-clause BSD: http://www.opensource.org/licenses/bsd-license.php
+ */
+static const gchar *valid_licenses[] = {
+  "LGPL",                       /* GNU Lesser General Public License */
+  "GPL",                        /* GNU General Public License */
+  "QPL",                        /* Trolltech Qt Public License */
+  "GPL/QPL",                    /* Combi-license of GPL + QPL */
+  "MPL",                        /* MPL 1.1 license */
+  "BSD",                        /* 3-clause BSD license */
+  "MIT/X11",                    /* MIT/X11 license */
+  "Proprietary",                /* Proprietary license */
+  GST_LICENSE_UNKNOWN,          /* some other license */
+  NULL
+};
+
+static GstPlugin *gst_plugin_register_func (GstPlugin * plugin,
+    const GstPluginDesc * desc);
+static void gst_plugin_desc_copy (GstPluginDesc * dest,
+    const GstPluginDesc * src);
+static void gst_plugin_desc_free (GstPluginDesc * desc);
+
+
+G_DEFINE_TYPE (GstPlugin, gst_plugin, GST_TYPE_OBJECT);
+
+static void
+gst_plugin_init (GstPlugin * plugin)
+{
+  /* do nothing, needed because of G_DEFINE_TYPE */
+}
+
+static void
+gst_plugin_finalize (GObject * object)
+{
+  GstPlugin *plugin = GST_PLUGIN_CAST (object);
+  GstRegistry *registry = gst_registry_get_default ();
+  GList *g;
+
+  GST_DEBUG ("finalizing plugin %p", plugin);
+  for (g = registry->plugins; g; g = g->next) {
+    if (g->data == (gpointer) plugin) {
+      g_warning ("removing plugin that is still in registry");
+    }
+  }
+  g_free (plugin->filename);
+  g_free (plugin->basename);
+  gst_plugin_desc_free (&plugin->desc);
+
+  G_OBJECT_CLASS (gst_plugin_parent_class)->finalize (object);
+}
+
+static void
+gst_plugin_class_init (GstPluginClass * klass)
+{
+  G_OBJECT_CLASS (klass)->finalize = GST_DEBUG_FUNCPTR (gst_plugin_finalize);
+}
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GQuark
+gst_plugin_error_quark (void)
+{
+  static GQuark quark = 0;
+
+  if (!quark)
+    quark = g_quark_from_static_string ("gst_plugin_error");
+  return quark;
+}
+
+#ifndef GST_REMOVE_DEPRECATED
+/* this function can be called in the GCC constructor extension, before
+ * the _gst_plugin_initialize() was called. In that case, we store the
+ * plugin description in a list to initialize it when we open the main
+ * module later on.
+ * When the main module is known, we can register the plugin right away.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+_gst_plugin_register_static (GstPluginDesc * desc)
+{
+  g_return_if_fail (desc != NULL);
+
+  if (!_gst_plugin_inited) {
+    /* We can't use any GLib functions here, since g_thread_init hasn't been
+     * called yet, and we can't call it here either, or programs that don't
+     * guard their g_thread_init calls in main() will just abort */
+    ++_num_static_plugins;
+    _static_plugins =
+        realloc (_static_plugins, _num_static_plugins * sizeof (GstPluginDesc));
+    /* assume strings in the GstPluginDesc are static const or live forever */
+    _static_plugins[_num_static_plugins - 1] = *desc;
+  } else {
+    gst_plugin_register_static (desc->major_version, desc->minor_version,
+        desc->name, desc->description, desc->plugin_init, desc->version,
+        desc->license, desc->source, desc->package, desc->origin);
+  }
+}
+#endif
+
+/**
+ * gst_plugin_register_static:
+ * @major_version: the major version number of the GStreamer core that the
+ *     plugin was compiled for, you can just use GST_VERSION_MAJOR here
+ * @minor_version: the minor version number of the GStreamer core that the
+ *     plugin was compiled for, you can just use GST_VERSION_MINOR here
+ * @name: a unique name of the plugin (ideally prefixed with an application- or
+ *     library-specific namespace prefix in order to avoid name conflicts in
+ *     case a similar plugin with the same name ever gets added to GStreamer)
+ * @description: description of the plugin
+ * @init_func: pointer to the init function of this plugin.
+ * @version: version string of the plugin
+ * @license: effective license of plugin. Must be one of the approved licenses
+ *     (see #GstPluginDesc above) or the plugin will not be registered.
+ * @source: source module plugin belongs to
+ * @package: shipped package plugin belongs to
+ * @origin: URL to provider of plugin
+ *
+ * Registers a static plugin, ie. a plugin which is private to an application
+ * or library and contained within the application or library (as opposed to
+ * being shipped as a separate module file).
+ *
+ * You must make sure that GStreamer has been initialised (with gst_init() or
+ * via gst_init_get_option_group()) before calling this function.
+ *
+ * Returns: TRUE if the plugin was registered correctly, otherwise FALSE.
+ *
+ * Since: 0.10.16
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_plugin_register_static (gint major_version, gint minor_version,
+    const gchar * name, gchar * description, GstPluginInitFunc init_func,
+    const gchar * version, const gchar * license, const gchar * source,
+    const gchar * package, const gchar * origin)
+{
+#ifdef __SYMBIAN32__
+  GstPluginDesc desc;
+  GstPlugin *plugin;
+  gboolean res = FALSE;
+
+  desc.major_version = major_version;
+  desc.minor_version = minor_version;
+  desc.name = name;
+  desc.description = description;
+  desc.plugin_init = init_func;
+  desc.version = version;
+  desc.license = license;
+  desc.source = source;
+  desc.package = package;
+  desc.origin = origin;
+#else
+  GstPluginDesc desc = { major_version, minor_version, name, description,
+    init_func, version, license, source, package, origin,
+  };
+  GstPlugin *plugin;
+  gboolean res = FALSE;
+#endif
+
+  g_return_val_if_fail (name != NULL, FALSE);
+  g_return_val_if_fail (description != NULL, FALSE);
+  g_return_val_if_fail (init_func != NULL, FALSE);
+  g_return_val_if_fail (version != NULL, FALSE);
+  g_return_val_if_fail (license != NULL, FALSE);
+  g_return_val_if_fail (source != NULL, FALSE);
+  g_return_val_if_fail (package != NULL, FALSE);
+  g_return_val_if_fail (origin != NULL, FALSE);
+
+  /* make sure gst_init() has been called */
+  g_return_val_if_fail (_gst_plugin_inited != FALSE, FALSE);
+
+  GST_LOG ("attempting to load static plugin \"%s\" now...", name);
+  plugin = g_object_new (GST_TYPE_PLUGIN, NULL);
+  if (gst_plugin_register_func (plugin, &desc) != NULL) {
+    GST_INFO ("registered static plugin \"%s\"", name);
+    res = gst_default_registry_add_plugin (plugin);
+    GST_INFO ("added static plugin \"%s\", result: %d", name, res);
+  }
+  return res;
+}
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+void
+_gst_plugin_initialize (void)
+{
+  guint i;
+
+  _gst_plugin_inited = TRUE;
+
+  /* now register all static plugins */
+  GST_INFO ("registering %u static plugins", _num_static_plugins);
+  for (i = 0; i < _num_static_plugins; ++i) {
+    gst_plugin_register_static (_static_plugins[i].major_version,
+        _static_plugins[i].minor_version, _static_plugins[i].name,
+        _static_plugins[i].description, _static_plugins[i].plugin_init,
+        _static_plugins[i].version, _static_plugins[i].license,
+        _static_plugins[i].source, _static_plugins[i].package,
+        _static_plugins[i].origin);
+  }
+
+  if (_static_plugins) {
+    free (_static_plugins);
+    _static_plugins = NULL;
+    _num_static_plugins = 0;
+  }
+}
+
+/* this function could be extended to check if the plugin license matches the
+ * applications license (would require the app to register its license somehow).
+ * We'll wait for someone who's interested in it to code it :)
+ */
+static gboolean
+gst_plugin_check_license (const gchar * license)
+{
+  const gchar **check_license = valid_licenses;
+
+  g_assert (check_license);
+
+  while (*check_license) {
+    if (strcmp (license, *check_license) == 0)
+      return TRUE;
+    check_license++;
+  }
+  return FALSE;
+}
+
+static gboolean
+gst_plugin_check_version (gint major, gint minor)
+{
+  /* return NULL if the major and minor version numbers are not compatible */
+  /* with ours. */
+  if (major != GST_VERSION_MAJOR || minor != GST_VERSION_MINOR)
+    return FALSE;
+
+  return TRUE;
+}
+
+static GstPlugin *
+gst_plugin_register_func (GstPlugin * plugin, const GstPluginDesc * desc)
+{
+  if (!gst_plugin_check_version (desc->major_version, desc->minor_version)) {
+    if (GST_CAT_DEFAULT)
+      GST_WARNING ("plugin \"%s\" has incompatible version, not loading",
+          plugin->filename);
+    return NULL;
+  }
+
+  if (!desc->license || !desc->description || !desc->source ||
+      !desc->package || !desc->origin) {
+    if (GST_CAT_DEFAULT)
+      GST_WARNING ("plugin \"%s\" has incorrect GstPluginDesc, not loading",
+          plugin->filename);
+    return NULL;
+  }
+
+  if (!gst_plugin_check_license (desc->license)) {
+    if (GST_CAT_DEFAULT)
+      GST_WARNING ("plugin \"%s\" has invalid license \"%s\", not loading",
+          plugin->filename, desc->license);
+    return NULL;
+  }
+
+  if (GST_CAT_DEFAULT)
+    GST_LOG ("plugin \"%s\" looks good", GST_STR_NULL (plugin->filename));
+
+  gst_plugin_desc_copy (&plugin->desc, desc);
+
+  if (!((desc->plugin_init) (plugin))) {
+    if (GST_CAT_DEFAULT)
+      GST_WARNING ("plugin \"%s\" failed to initialise", plugin->filename);
+    plugin->module = NULL;
+    return NULL;
+  }
+
+  if (GST_CAT_DEFAULT)
+    GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename));
+
+  return plugin;
+}
+
+#ifdef HAVE_SIGACTION
+static struct sigaction oldaction;
+
+/*
+ * _gst_plugin_fault_handler_restore:
+ * segfault handler restorer
+ */
+static void
+_gst_plugin_fault_handler_restore (void)
+{
+  if (!_gst_plugin_fault_handler_is_setup)
+    return;
+
+  _gst_plugin_fault_handler_is_setup = FALSE;
+
+  sigaction (SIGSEGV, &oldaction, NULL);
+}
+
+/*
+ * _gst_plugin_fault_handler_sighandler:
+ * segfault handler implementation
+ */
+static void
+_gst_plugin_fault_handler_sighandler (int signum)
+{
+  /* We need to restore the fault handler or we'll keep getting it */
+  _gst_plugin_fault_handler_restore ();
+
+  switch (signum) {
+    case SIGSEGV:
+      g_print ("\nERROR: ");
+      g_print ("Caught a segmentation fault while loading plugin file:\n");
+      g_print ("%s\n\n", _gst_plugin_fault_handler_filename);
+      g_print ("Please either:\n");
+      g_print ("- remove it and restart.\n");
+      g_print ("- run with --gst-disable-segtrap and debug.\n");
+      exit (-1);
+      break;
+    default:
+      g_print ("Caught unhandled signal on plugin loading\n");
+      break;
+  }
+}
+
+/*
+ * _gst_plugin_fault_handler_setup:
+ * sets up the segfault handler
+ */
+static void
+_gst_plugin_fault_handler_setup (void)
+{
+  struct sigaction action;
+
+  /* if asked to leave segfaults alone, just return */
+  if (!gst_segtrap_is_enabled ())
+    return;
+
+  if (_gst_plugin_fault_handler_is_setup)
+    return;
+
+  _gst_plugin_fault_handler_is_setup = TRUE;
+
+  memset (&action, 0, sizeof (action));
+  action.sa_handler = _gst_plugin_fault_handler_sighandler;
+
+  sigaction (SIGSEGV, &action, &oldaction);
+}
+#else
+static void
+_gst_plugin_fault_handler_restore (void)
+{
+}
+
+static void
+_gst_plugin_fault_handler_setup (void)
+{
+}
+#endif
+
+static void _gst_plugin_fault_handler_setup ();
+
+static GStaticMutex gst_plugin_loading_mutex = G_STATIC_MUTEX_INIT;
+
+/**
+ * gst_plugin_load_file:
+ * @filename: the plugin filename to load
+ * @error: pointer to a NULL-valued GError
+ *
+ * Loads the given plugin and refs it.  Caller needs to unref after use.
+ *
+ * Returns: a reference to the existing loaded GstPlugin, a reference to the
+ * newly-loaded GstPlugin, or NULL if an error occurred.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstPlugin *
+gst_plugin_load_file (const gchar * filename, GError ** error)
+{
+  GstPlugin *plugin;
+  GModule *module;
+  gboolean ret;
+  gpointer ptr;
+  struct stat file_status;
+  GstRegistry *registry;
+   #ifdef __SYMBIAN32__
+   GstPluginDesc* (*fn)(void)=NULL;
+   void *temp;
+   
+   #endif
+
+  g_return_val_if_fail (filename != NULL, NULL);
+
+  registry = gst_registry_get_default ();
+  g_static_mutex_lock (&gst_plugin_loading_mutex);
+
+  plugin = gst_registry_lookup (registry, filename);
+  if (plugin) {
+    if (plugin->module) {
+      g_static_mutex_unlock (&gst_plugin_loading_mutex);
+      return plugin;
+    } else {
+      gst_object_unref (plugin);
+      plugin = NULL;
+    }
+  }
+
+  GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"",
+      filename);
+
+  if (g_module_supported () == FALSE) {
+    GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "module loading not supported");
+    g_set_error (error,
+        GST_PLUGIN_ERROR,
+        GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported");
+    goto return_error;
+  }
+
+  if (g_stat (filename, &file_status)) {
+    GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "problem accessing file");
+    g_set_error (error,
+        GST_PLUGIN_ERROR,
+        GST_PLUGIN_ERROR_MODULE, "Problem accessing file %s: %s", filename,
+        g_strerror (errno));
+    goto return_error;
+  }
+
+  module = g_module_open (filename, G_MODULE_BIND_LOCAL);
+  if (module == NULL) {
+    GST_CAT_WARNING (GST_CAT_PLUGIN_LOADING, "module_open failed: %s",
+        g_module_error ());
+    g_set_error (error,
+        GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Opening module failed: %s",
+        g_module_error ());
+    /* If we failed to open the shared object, then it's probably because a
+     * plugin is linked against the wrong libraries. Print out an easy-to-see
+     * message in this case. */
+    g_warning ("Failed to load plugin '%s': %s", filename, g_module_error ());
+    goto return_error;
+  }
+
+  plugin = g_object_new (GST_TYPE_PLUGIN, NULL);
+
+  plugin->module = module;
+  plugin->filename = g_strdup (filename);
+  plugin->basename = g_path_get_basename (filename);
+  plugin->file_mtime = file_status.st_mtime;
+  plugin->file_size = file_status.st_size;
+
+#ifdef __SYMBIAN32__
+   ret = g_module_symbol (module, "1", &ptr);
+#else   
+  ret = g_module_symbol (module, "gst_plugin_desc", &ptr);
+#endif   
+  if (!ret) {
+    GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename);
+    g_set_error (error,
+        GST_PLUGIN_ERROR,
+        GST_PLUGIN_ERROR_MODULE,
+        "File \"%s\" is not a GStreamer plugin", filename);
+    g_module_close (module);
+    goto return_error;
+  }
+   #ifdef __SYMBIAN32__
+   fn=ptr;
+   temp=fn();
+   plugin->orig_desc = (GstPluginDesc *) temp;
+   #else
+  plugin->orig_desc = (GstPluginDesc *) ptr;
+   #endif
+
+  GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...",
+      plugin, filename);
+
+  /* this is where we load the actual .so, so let's trap SIGSEGV */
+  _gst_plugin_fault_handler_setup ();
+  _gst_plugin_fault_handler_filename = plugin->filename;
+
+  GST_LOG ("Plugin %p for file \"%s\" prepared, registering...",
+      plugin, filename);
+
+  if (!gst_plugin_register_func (plugin, plugin->orig_desc)) {
+    /* remove signal handler */
+    _gst_plugin_fault_handler_restore ();
+    GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename);
+    /* plugin == NULL */
+    g_set_error (error,
+        GST_PLUGIN_ERROR,
+        GST_PLUGIN_ERROR_MODULE,
+        "File \"%s\" appears to be a GStreamer plugin, but it failed to initialize",
+        filename);
+    g_module_close (module);
+    goto return_error;
+  }
+
+  /* remove signal handler */
+  _gst_plugin_fault_handler_restore ();
+  _gst_plugin_fault_handler_filename = NULL;
+  GST_INFO ("plugin \"%s\" loaded", plugin->filename);
+
+  gst_object_ref (plugin);
+  gst_default_registry_add_plugin (plugin);
+
+  g_static_mutex_unlock (&gst_plugin_loading_mutex);
+  return plugin;
+
+return_error:
+  {
+    if (plugin)
+      gst_object_unref (plugin);
+    g_static_mutex_unlock (&gst_plugin_loading_mutex);
+    return NULL;
+  }
+}
+
+static void
+gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src)
+{
+  dest->major_version = src->major_version;
+  dest->minor_version = src->minor_version;
+  dest->name = g_intern_string (src->name);
+  /* maybe intern the description too, just for convenience? */
+  dest->description = g_strdup (src->description);
+  dest->plugin_init = src->plugin_init;
+  dest->version = g_intern_string (src->version);
+  dest->license = g_intern_string (src->license);
+  dest->source = g_intern_string (src->source);
+  dest->package = g_intern_string (src->package);
+  dest->origin = g_intern_string (src->origin);
+}
+
+/* unused */
+static void
+gst_plugin_desc_free (GstPluginDesc * desc)
+{
+  g_free (desc->description);
+  memset (desc, 0, sizeof (GstPluginDesc));
+}
+
+/**
+ * gst_plugin_get_name:
+ * @plugin: plugin to get the name of
+ *
+ * Get the short name of the plugin
+ *
+ * Returns: the name of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+const gchar *
+gst_plugin_get_name (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.name;
+}
+
+/**
+ * gst_plugin_get_description:
+ * @plugin: plugin to get long name of
+ *
+ * Get the long descriptive name of the plugin
+ *
+ * Returns: the long name of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_description (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.description;
+}
+
+/**
+ * gst_plugin_get_filename:
+ * @plugin: plugin to get the filename of
+ *
+ * get the filename of the plugin
+ *
+ * Returns: the filename of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_filename (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->filename;
+}
+
+/**
+ * gst_plugin_get_version:
+ * @plugin: plugin to get the version of
+ *
+ * get the version of the plugin
+ *
+ * Returns: the version of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_version (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.version;
+}
+
+/**
+ * gst_plugin_get_license:
+ * @plugin: plugin to get the license of
+ *
+ * get the license of the plugin
+ *
+ * Returns: the license of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_license (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.license;
+}
+
+/**
+ * gst_plugin_get_source:
+ * @plugin: plugin to get the source of
+ *
+ * get the source module the plugin belongs to.
+ *
+ * Returns: the source of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_source (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.source;
+}
+
+/**
+ * gst_plugin_get_package:
+ * @plugin: plugin to get the package of
+ *
+ * get the package the plugin belongs to.
+ *
+ * Returns: the package of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_package (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.package;
+}
+
+/**
+ * gst_plugin_get_origin:
+ * @plugin: plugin to get the origin of
+ *
+ * get the URL where the plugin comes from
+ *
+ * Returns: the origin of the plugin
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+G_CONST_RETURN gchar *
+gst_plugin_get_origin (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->desc.origin;
+}
+
+/**
+ * gst_plugin_get_module:
+ * @plugin: plugin to query
+ *
+ * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is
+ * returned.
+ *
+ * Returns: module belonging to the plugin or NULL if the plugin isn't
+ *          loaded yet.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GModule *
+gst_plugin_get_module (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, NULL);
+
+  return plugin->module;
+}
+
+/**
+ * gst_plugin_is_loaded:
+ * @plugin: plugin to query
+ *
+ * queries if the plugin is loaded into memory
+ *
+ * Returns: TRUE is loaded, FALSE otherwise
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_plugin_is_loaded (GstPlugin * plugin)
+{
+  g_return_val_if_fail (plugin != NULL, FALSE);
+
+  return (plugin->module != NULL || plugin->filename == NULL);
+}
+
+#if 0
+/**
+ * gst_plugin_feature_list:
+ * @plugin: plugin to query
+ * @filter: the filter to use
+ * @first: only return first match
+ * @user_data: user data passed to the filter function
+ *
+ * Runs a filter against all plugin features and returns a GList with
+ * the results. If the first flag is set, only the first match is
+ * returned (as a list with a single object).
+ *
+ * Returns: a GList of features, g_list_free after use.
+ */
+GList *
+gst_plugin_feature_filter (GstPlugin * plugin,
+    GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
+{
+  GList *list;
+  GList *g;
+
+  list = gst_filter_run (plugin->features, (GstFilterFunc) filter, first,
+      user_data);
+  for (g = list; g; g = g->next) {
+    gst_object_ref (plugin);
+  }
+
+  return list;
+}
+
+typedef struct
+{
+  GstPluginFeatureFilter filter;
+  gboolean first;
+  gpointer user_data;
+  GList *result;
+}
+FeatureFilterData;
+
+static gboolean
+_feature_filter (GstPlugin * plugin, gpointer user_data)
+{
+  GList *result;
+  FeatureFilterData *data = (FeatureFilterData *) user_data;
+
+  result = gst_plugin_feature_filter (plugin, data->filter, data->first,
+      data->user_data);
+  if (result) {
+    data->result = g_list_concat (data->result, result);
+    return TRUE;
+  }
+  return FALSE;
+}
+
+/**
+ * gst_plugin_list_feature_filter:
+ * @list: a #GList of plugins to query
+ * @filter: the filter function to use
+ * @first: only return first match
+ * @user_data: user data passed to the filter function
+ *
+ * Runs a filter against all plugin features of the plugins in the given
+ * list and returns a GList with the results.
+ * If the first flag is set, only the first match is
+ * returned (as a list with a single object).
+ *
+ * Returns: a GList of features, g_list_free after use.
+ */
+GList *
+gst_plugin_list_feature_filter (GList * list,
+    GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
+{
+  FeatureFilterData data;
+  GList *result;
+
+  data.filter = filter;
+  data.first = first;
+  data.user_data = user_data;
+  data.result = NULL;
+
+  result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data);
+  g_list_free (result);
+
+  return data.result;
+}
+#endif
+
+/**
+ * gst_plugin_name_filter:
+ * @plugin: the plugin to check
+ * @name: the name of the plugin
+ *
+ * A standard filter that returns TRUE when the plugin is of the
+ * given name.
+ *
+ * Returns: TRUE if the plugin is of the given name.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_plugin_name_filter (GstPlugin * plugin, const gchar * name)
+{
+  return (plugin->desc.name && !strcmp (plugin->desc.name, name));
+}
+
+#if 0
+/**
+ * gst_plugin_find_feature:
+ * @plugin: plugin to get the feature from
+ * @name: The name of the feature to find
+ * @type: The type of the feature to find
+ *
+ * Find a feature of the given name and type in the given plugin.
+ *
+ * Returns: a GstPluginFeature or NULL if the feature was not found.
+ */
+GstPluginFeature *
+gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type)
+{
+  GList *walk;
+  GstPluginFeature *result = NULL;
+  GstTypeNameData data;
+
+  g_return_val_if_fail (name != NULL, NULL);
+
+  data.type = type;
+  data.name = name;
+
+  walk = gst_filter_run (plugin->features,
+      (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data);
+
+  if (walk) {
+    result = GST_PLUGIN_FEATURE (walk->data);
+
+    gst_object_ref (result);
+    gst_plugin_feature_list_free (walk);
+  }
+
+  return result;
+}
+#endif
+
+#if 0
+static gboolean
+gst_plugin_feature_name_filter (GstPluginFeature * feature, const gchar * name)
+{
+  return !strcmp (name, GST_PLUGIN_FEATURE_NAME (feature));
+}
+#endif
+
+#if 0
+/**
+ * gst_plugin_find_feature_by_name:
+ * @plugin: plugin to get the feature from
+ * @name: The name of the feature to find
+ *
+ * Find a feature of the given name in the given plugin.
+ *
+ * Returns: a GstPluginFeature or NULL if the feature was not found.
+ */
+GstPluginFeature *
+gst_plugin_find_feature_by_name (GstPlugin * plugin, const gchar * name)
+{
+  GList *walk;
+  GstPluginFeature *result = NULL;
+
+  g_return_val_if_fail (name != NULL, NULL);
+
+  walk = gst_filter_run (plugin->features,
+      (GstFilterFunc) gst_plugin_feature_name_filter, TRUE, (void *) name);
+
+  if (walk) {
+    result = GST_PLUGIN_FEATURE (walk->data);
+
+    gst_object_ref (result);
+    gst_plugin_feature_list_free (walk);
+  }
+
+  return result;
+}
+#endif
+
+/**
+ * gst_plugin_load_by_name:
+ * @name: name of plugin to load
+ *
+ * Load the named plugin. Refs the plugin.
+ *
+ * Returns: A reference to a loaded plugin, or NULL on error.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstPlugin *
+gst_plugin_load_by_name (const gchar * name)
+{
+  GstPlugin *plugin, *newplugin;
+  GError *error = NULL;
+
+  GST_DEBUG ("looking up plugin %s in default registry", name);
+  plugin = gst_registry_find_plugin (gst_registry_get_default (), name);
+  if (plugin) {
+    GST_DEBUG ("loading plugin %s from file %s", name, plugin->filename);
+    newplugin = gst_plugin_load_file (plugin->filename, &error);
+    gst_object_unref (plugin);
+
+    if (!newplugin) {
+      GST_WARNING ("load_plugin error: %s", error->message);
+      g_error_free (error);
+      return NULL;
+    }
+    /* newplugin was reffed by load_file */
+    return newplugin;
+  }
+
+  GST_DEBUG ("Could not find plugin %s in registry", name);
+  return NULL;
+}
+
+/**
+ * gst_plugin_load:
+ * @plugin: plugin to load
+ *
+ * Loads @plugin. Note that the *return value* is the loaded plugin; @plugin is
+ * untouched. The normal use pattern of this function goes like this:
+ *
+ * <programlisting>
+ * GstPlugin *loaded_plugin;
+ * loaded_plugin = gst_plugin_load (plugin);
+ * // presumably, we're no longer interested in the potentially-unloaded plugin
+ * gst_object_unref (plugin);
+ * plugin = loaded_plugin;
+ * </programlisting>
+ *
+ * Returns: A reference to a loaded plugin, or NULL on error.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+GstPlugin *
+gst_plugin_load (GstPlugin * plugin)
+{
+  GError *error = NULL;
+  GstPlugin *newplugin;
+
+  if (gst_plugin_is_loaded (plugin)) {
+    return plugin;
+  }
+
+  if (!(newplugin = gst_plugin_load_file (plugin->filename, &error)))
+    goto load_error;
+
+  return newplugin;
+
+load_error:
+  {
+    GST_WARNING ("load_plugin error: %s", error->message);
+    g_error_free (error);
+    return NULL;
+  }
+}
+
+/**
+ * gst_plugin_list_free:
+ * @list: list of #GstPlugin
+ *
+ * Unrefs each member of @list, then frees the list.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_plugin_list_free (GList * list)
+{
+  GList *g;
+
+  for (g = list; g; g = g->next) {
+    gst_object_unref (GST_PLUGIN_CAST (g->data));
+  }
+  g_list_free (list);
+}