gstreamer/gst/gstregistry.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2005 David A. Schleef <ds@schleef.org>
*
* gstregistry.c: handle registry
*
* 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:gstregistry
* @short_description: Abstract base class for management of #GstPlugin objects
* @see_also: #GstPlugin, #GstPluginFeature
*
* One registry holds the metadata of a set of plugins.
* All registries build the #GstRegistryPool.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst_private.h"
#include <glib.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include "gstinfo.h"
#include "gstregistry.h"
#include "gstmarshal.h"
#include "gstfilter.h"
#define GST_CAT_DEFAULT GST_CAT_REGISTRY
/* the one instance of the default registry */
static GstRegistry *_gst_registry_default = NULL;
/*
* Design:
*
* The GstRegistry object is a list of plugins and some functions
* for dealing with them. Plugins are matched 1-1 with a file on
* disk, and may or may not be loaded at a given time. There may
* be multiple GstRegistry objects, but the "default registry" is
* the only object that has any meaning to the core.
*
* The registry.xml file in 0.9 is actually a cache of plugin
* information. This is unlike previous versions, where the registry
* file was the primary source of plugin information, and was created
* by the gst-register command.
*
* In 0.9, the primary source, at all times, of plugin information
* is each plugin file itself. Thus, if an application wants
* information about a particular plugin, or wants to search for
* a feature that satisfies given criteria, the primary means of
* doing so is to load every plugin and look at the resulting
* information that is gathered in the default registry. Clearly,
* this is a time consuming process, so we cache information in
* the registry.xml file.
*
* On startup, plugins are searched for in the plugin search path.
* This path can be set directly using the GST_PLUGIN_PATH
* environment variable. The registry file is loaded from
* ~/.gstreamer-0.9/registry.xml or the file listed in the
* GST_REGISTRY env var. The only reason to change the registry
* location is for testing.
*
* For each plugin that is found in the plugin search path, there
* could be 3 possibilities for cached information:
* - the cache may not contain information about a given file.
* - the cache may have stale information.
* - the cache may have current information.
* In the first two cases, the plugin is loaded and the cache
* updated. In addition to these cases, the cache may have entries
* for plugins that are not relevant to the current process. These
* are marked as not available to the current process. If the
* cache is updated for whatever reason, it is marked dirty.
*
* A dirty cache is written out at the end of initialization. Each
* entry is checked to make sure the information is minimally valid.
* If not, the entry is simply dropped.
*
* Implementation notes:
*
* The "cache" and "default registry" are different concepts and
* can represent different sets of plugins. For various reasons,
* at init time, the cache is stored in the default registry, and
* plugins not relevant to the current process are marked with the
* GST_PLUGIN_FLAG_CACHED bit. These plugins are removed at the
* end of intitialization.
*
*/
/* Element signals and args */
enum
{
PLUGIN_ADDED,
FEATURE_ADDED,
LAST_SIGNAL
};
static void gst_registry_class_init (GstRegistryClass * klass);
static void gst_registry_init (GstRegistry * registry);
static void gst_registry_finalize (GObject * object);
static guint gst_registry_signals[LAST_SIGNAL] = { 0 };
static GstPluginFeature *gst_registry_lookup_feature_locked (GstRegistry *
registry, const char *name);
static GstPlugin *gst_registry_lookup_locked (GstRegistry * registry,
const char *filename);
G_DEFINE_TYPE (GstRegistry, gst_registry, GST_TYPE_OBJECT);
static GstObjectClass *parent_class = NULL;
static void
gst_registry_class_init (GstRegistryClass * klass)
{
GObjectClass *gobject_class;
gobject_class = (GObjectClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_OBJECT);
gst_registry_signals[PLUGIN_ADDED] =
g_signal_new ("plugin-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstRegistryClass, plugin_added), NULL,
NULL, gst_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
gst_registry_signals[FEATURE_ADDED] =
g_signal_new ("feature-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstRegistryClass, feature_added),
NULL, NULL, gst_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_registry_finalize);
}
static void
gst_registry_init (GstRegistry * registry)
{
}
static void
gst_registry_finalize (GObject * object)
{
GstRegistry *registry = GST_REGISTRY (object);
GList *plugins, *p;
GList *features, *f;
plugins = registry->plugins;
registry->plugins = NULL;
GST_DEBUG_OBJECT (registry, "registry finalize");
p = plugins;
while (p) {
GstPlugin *plugin = p->data;
if (plugin) {
GST_DEBUG_OBJECT (registry, "removing plugin %s",
gst_plugin_get_name (plugin));
gst_registry_remove_plugin (registry, plugin);
}
p = g_list_next (p);
}
g_list_free (plugins);
features = registry->features;
registry->features = NULL;
f = features;
while (f) {
GstPluginFeature *feature = f->data;
if (feature) {
gst_registry_remove_feature (registry, feature);
}
f = g_list_next (f);
}
g_list_free (features);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
/**
* gst_registry_get_default:
*
* Retrieves the default registry. The caller does not own a reference on the
* registry, as it is alive as long as GStreamer is initialized.
*/
GstRegistry *
gst_registry_get_default (void)
{
if (!_gst_registry_default) {
_gst_registry_default = g_object_new (GST_TYPE_REGISTRY, NULL);
}
return _gst_registry_default;
}
/**
* gst_registry_add_path:
* @registry: the registry to add the path to
* @path: the path to add to the registry
*
* Add the given path to the registry. The syntax of the
* path is specific to the registry. If the path has already been
* added, do nothing.
*/
void
gst_registry_add_path (GstRegistry * registry, const gchar * path)
{
g_return_if_fail (GST_IS_REGISTRY (registry));
g_return_if_fail (path != NULL);
if (strlen (path) == 0) {
GST_INFO ("Ignoring empty plugin path");
return;
}
GST_OBJECT_LOCK (registry);
if (g_list_find_custom (registry->paths, path, (GCompareFunc) strcmp)) {
g_warning ("path %s already added to registry", path);
GST_OBJECT_UNLOCK (registry);
return;
}
GST_INFO ("Adding plugin path: \"%s\"", path);
registry->paths = g_list_append (registry->paths, g_strdup (path));
GST_OBJECT_UNLOCK (registry);
}
/**
* gst_registry_get_path_list:
* @registry: the registry to get the pathlist of
*
* Get the list of paths for the given registry.
*
* Returns: A Glist of paths as strings. g_list_free after use.
*/
GList *
gst_registry_get_path_list (GstRegistry * registry)
{
GList *list;
g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
GST_OBJECT_LOCK (registry);
/* We don't need to copy the strings, because they won't be deleted
* as long as the GstRegistry is around */
list = g_list_copy (registry->paths);
GST_OBJECT_UNLOCK (registry);
return list;
}
/**
* gst_registry_add_plugin:
* @registry: the registry to add the plugin to
* @plugin: the plugin to add
*
* Add the plugin to the registry. The plugin-added signal will be emitted.
*
* Returns: TRUE on success.
*/
gboolean
gst_registry_add_plugin (GstRegistry * registry, GstPlugin * plugin)
{
GstPlugin *existing_plugin;
g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);
GST_OBJECT_LOCK (registry);
existing_plugin = gst_registry_lookup_locked (registry, plugin->filename);
if (existing_plugin) {
GST_DEBUG_OBJECT (registry,
"Replacing existing plugin %p with new plugin %p for filename \"%s\"",
existing_plugin, plugin, GST_STR_NULL (plugin->filename));
registry->plugins = g_list_remove (registry->plugins, existing_plugin);
gst_object_unref (existing_plugin);
}
GST_DEBUG_OBJECT (registry, "adding plugin %p for filename \"%s\"",
plugin, GST_STR_NULL (plugin->filename));
registry->plugins = g_list_prepend (registry->plugins, plugin);
gst_object_ref (plugin);
gst_object_sink (plugin);
GST_OBJECT_UNLOCK (registry);
GST_DEBUG_OBJECT (registry, "emitting plugin-added for filename \"%s\"",
GST_STR_NULL (plugin->filename));
g_signal_emit (G_OBJECT (registry), gst_registry_signals[PLUGIN_ADDED], 0,
plugin);
return TRUE;
}
/**
* gst_registry_remove_plugin:
* @registry: the registry to remove the plugin from
* @plugin: the plugin to remove
*
* Remove the plugin from the registry.
*/
void
gst_registry_remove_plugin (GstRegistry * registry, GstPlugin * plugin)
{
g_return_if_fail (GST_IS_REGISTRY (registry));
GST_OBJECT_LOCK (registry);
registry->plugins = g_list_remove (registry->plugins, plugin);
GST_OBJECT_UNLOCK (registry);
gst_object_unref (plugin);
}
/**
* gst_registry_add_feature:
* @registry: the registry to add the plugin to
* @feature: the feature to add
*
* Add the feature to the registry. The feature-added signal will be emitted.
*
* Returns: TRUE on success.
*/
gboolean
gst_registry_add_feature (GstRegistry * registry, GstPluginFeature * feature)
{
GstPluginFeature *existing_feature;
g_return_val_if_fail (GST_IS_REGISTRY (registry), FALSE);
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);
g_return_val_if_fail (feature->name != NULL, FALSE);
g_return_val_if_fail (feature->plugin_name != NULL, FALSE);
GST_OBJECT_LOCK (registry);
existing_feature = gst_registry_lookup_feature_locked (registry,
feature->name);
if (existing_feature) {
GST_DEBUG_OBJECT (registry, "Replacing existing feature %p (%s)",
existing_feature, feature->name);
registry->features = g_list_remove (registry->features, existing_feature);
gst_object_unref (existing_feature);
}
GST_DEBUG_OBJECT (registry, "adding feature %p (%s)", feature, feature->name);
registry->features = g_list_prepend (registry->features, feature);
gst_object_ref (feature);
gst_object_sink (feature);
GST_OBJECT_UNLOCK (registry);
GST_DEBUG_OBJECT (registry, "emitting feature-added for %s", feature->name);
g_signal_emit (G_OBJECT (registry), gst_registry_signals[FEATURE_ADDED], 0,
feature);
return TRUE;
}
/**
* gst_registry_remove_feature:
* @registry: the registry to remove the feature from
* @feature: the feature to remove
*
* Remove the feature from the registry.
*/
void
gst_registry_remove_feature (GstRegistry * registry, GstPluginFeature * feature)
{
g_return_if_fail (GST_IS_REGISTRY (registry));
GST_DEBUG_OBJECT (registry, "removing feature %p (%s)",
feature, gst_plugin_feature_get_name (feature));
GST_OBJECT_LOCK (registry);
registry->features = g_list_remove (registry->features, feature);
GST_OBJECT_UNLOCK (registry);
gst_object_unref (feature);
}
/**
* gst_registry_plugin_filter:
* @registry: registry 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 plugins in the registry 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).
* Every plugin is reffed; use gst_plugin_list_free() after use, which
* will unref again.
*
* Returns: a #GList of #GstPlugin
*/
GList *
gst_registry_plugin_filter (GstRegistry * registry,
GstPluginFilter filter, gboolean first, gpointer user_data)
{
GList *list;
GList *g;
g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
GST_OBJECT_LOCK (registry);
list = gst_filter_run (registry->plugins, (GstFilterFunc) filter, first,
user_data);
for (g = list; g; g = g->next) {
gst_object_ref (GST_PLUGIN (g->data));
}
GST_OBJECT_UNLOCK (registry);
return list;
}
/**
* gst_registry_feature_filter:
* @registry: registry 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 features of the plugins in the registry
* 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 plugin features, gst_plugin_feature_list_free after use.
*/
GList *
gst_registry_feature_filter (GstRegistry * registry,
GstPluginFeatureFilter filter, gboolean first, gpointer user_data)
{
GList *list;
GList *g;
g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
GST_OBJECT_LOCK (registry);
list = gst_filter_run (registry->features, (GstFilterFunc) filter, first,
user_data);
for (g = list; g; g = g->next) {
gst_object_ref (GST_PLUGIN_FEATURE (g->data));
}
GST_OBJECT_UNLOCK (registry);
return list;
}
/**
* gst_registry_find_plugin:
* @registry: the registry to search
* @name: the plugin name to find
*
* Find the plugin with the given name in the registry.
* The plugin will be reffed; caller is responsible for unreffing.
*
* Returns: The plugin with the given name or NULL if the plugin was not found.
*/
GstPlugin *
gst_registry_find_plugin (GstRegistry * registry, const gchar * name)
{
GList *walk;
GstPlugin *result = NULL;
g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
g_return_val_if_fail (name != NULL, NULL);
walk = gst_registry_plugin_filter (registry,
(GstPluginFilter) gst_plugin_name_filter, TRUE, (gpointer) name);
if (walk) {
result = GST_PLUGIN (walk->data);
gst_object_ref (result);
gst_plugin_list_free (walk);
}
return result;
}
/**
* gst_registry_find_feature:
* @registry: the registry to search
* @name: the pluginfeature name to find
* @type: the pluginfeature type to find
*
* Find the pluginfeature with the given name and type in the registry.
*
* Returns: The pluginfeature with the given name and type or NULL
* if the plugin was not found.
*/
GstPluginFeature *
gst_registry_find_feature (GstRegistry * registry, const gchar * name,
GType type)
{
GstPluginFeature *feature = NULL;
GList *walk;
GstTypeNameData data;
g_return_val_if_fail (GST_IS_REGISTRY (registry), NULL);
g_return_val_if_fail (name != NULL, NULL);
data.name = name;
data.type = type;
walk = gst_registry_feature_filter (registry,
(GstPluginFeatureFilter) gst_plugin_feature_type_name_filter,
TRUE, &data);
if (walk) {
feature = GST_PLUGIN_FEATURE (walk->data);
gst_object_ref (feature);
gst_plugin_feature_list_free (walk);
}
return feature;
}
GList *
gst_registry_get_feature_list (GstRegistry * registry, GType type)
{
GstTypeNameData data;
data.type = type;
data.name = NULL;
return gst_registry_feature_filter (registry,
(GstPluginFeatureFilter) gst_plugin_feature_type_name_filter,
FALSE, &data);
}
/**
* gst_registry_get_plugin_list:
* @registry: the registry to search
*
* Get a copy of all plugins registered in the given registry.
*
* Returns: a copy of the list. Free after use.
*/
GList *
gst_registry_get_plugin_list (GstRegistry * registry)
{
GList *list;
GList *g;
GST_OBJECT_LOCK (registry);
list = g_list_copy (registry->plugins);
for (g = list; g; g = g->next) {
gst_object_ref (GST_PLUGIN (g->data));
}
GST_OBJECT_UNLOCK (registry);
return list;
}
static GstPluginFeature *
gst_registry_lookup_feature_locked (GstRegistry * registry, const char *name)
{
GList *g;
GstPluginFeature *feature;
if (name == NULL)
return NULL;
for (g = registry->features; g; g = g_list_next (g)) {
feature = GST_PLUGIN_FEATURE (g->data);
if (feature->name && strcmp (name, feature->name) == 0) {
return feature;
}
}
return NULL;
}
GstPluginFeature *
gst_registry_lookup_feature (GstRegistry * registry, const char *name)
{
GstPluginFeature *feature;
GST_OBJECT_LOCK (registry);
feature = gst_registry_lookup_feature_locked (registry, name);
if (feature)
gst_object_ref (feature);
GST_OBJECT_UNLOCK (registry);
return feature;
}
static GstPlugin *
gst_registry_lookup_locked (GstRegistry * registry, const char *filename)
{
GList *g;
GstPlugin *plugin;
gchar *basename;
if (filename == NULL)
return NULL;
basename = g_path_get_basename (filename);
for (g = registry->plugins; g; g = g_list_next (g)) {
plugin = GST_PLUGIN (g->data);
if (plugin->basename && strcmp (basename, plugin->basename) == 0) {
g_free (basename);
return plugin;
}
}
g_free (basename);
return NULL;
}
/**
* gst_registry_lookup:
* @registry: the registry to look up in
* @filename: the name of the file to look up
*
* Look up a plugin in the given registry with the given filename.
* If found, plugin is reffed. Caller must unref after use.
*
* Returns: the #GstPlugin if found, or NULL if not.
*/
GstPlugin *
gst_registry_lookup (GstRegistry * registry, const char *filename)
{
GstPlugin *plugin;
GST_OBJECT_LOCK (registry);
plugin = gst_registry_lookup_locked (registry, filename);
if (plugin)
gst_object_ref (plugin);
GST_OBJECT_UNLOCK (registry);
return plugin;
}
static void
gst_registry_scan_path_level (GstRegistry * registry, const gchar * path,
int level)
{
GDir *dir;
const gchar *dirent;
gchar *filename;
GstPlugin *plugin;
GstPlugin *newplugin;
dir = g_dir_open (path, 0, NULL);
if (!dir)
return;
while ((dirent = g_dir_read_name (dir))) {
filename = g_strjoin ("/", path, dirent, NULL);
GST_LOG_OBJECT (registry, "examining file: %s", filename);
if (g_file_test (filename, G_FILE_TEST_IS_DIR)) {
if (level > 0) {
GST_LOG_OBJECT (registry, "found directory, recursing");
gst_registry_scan_path_level (registry, filename, level - 1);
} else {
GST_LOG_OBJECT (registry,
"found directory, but recursion level is too deep");
}
g_free (filename);
continue;
}
if (!g_file_test (filename, G_FILE_TEST_IS_REGULAR)) {
GST_LOG_OBJECT (registry, "not a regular file, ignoring");
g_free (filename);
continue;
}
if (!g_str_has_suffix (filename, ".so") &&
!g_str_has_suffix (filename, ".dll") &&
!g_str_has_suffix (filename, ".dynlib")) {
GST_LOG_OBJECT (registry,
"extension is not recognized as module file, ignoring");
g_free (filename);
continue;
}
/* plug-ins are considered unique by basename; if the given name
* was already seen by the registry, we ignore it */
plugin = gst_registry_lookup (registry, filename);
if (plugin) {
struct stat file_status;
if (stat (filename, &file_status)) {
/* FIXME remove from cache */
g_free (filename);
continue;
}
if (plugin->registered) {
GST_DEBUG_OBJECT (registry,
"plugin already registered from path \"%s\"",
GST_STR_NULL (plugin->filename));
g_free (filename);
gst_object_unref (plugin);
continue;
}
if (plugin->file_mtime == file_status.st_mtime &&
plugin->file_size == file_status.st_size) {
GST_DEBUG_OBJECT (registry, "file %s cached", filename);
plugin->flags &= ~GST_PLUGIN_FLAG_CACHED;
GST_DEBUG_OBJECT (registry, "marking plugin %p as registered", plugin);
plugin->registered = TRUE;
} else {
GST_INFO_OBJECT (registry, "cached info for %s is stale", filename);
GST_DEBUG_OBJECT (registry, "mtime %ld != %ld or size %"
G_GSIZE_FORMAT " != %"
G_GSIZE_FORMAT, plugin->file_mtime, file_status.st_mtime,
plugin->file_size, file_status.st_size);
gst_registry_remove_plugin (gst_registry_get_default (), plugin);
newplugin = gst_plugin_load_file (filename, NULL);
if (newplugin) {
GST_DEBUG_OBJECT (registry, "marking new plugin %p as registered",
newplugin);
newplugin->registered = TRUE;
gst_object_unref (newplugin);
}
}
gst_object_unref (plugin);
} else {
GST_DEBUG_OBJECT (registry, "file %s not yet in registry", filename);
newplugin = gst_plugin_load_file (filename, NULL);
if (newplugin) {
newplugin->registered = TRUE;
gst_object_unref (newplugin);
}
}
g_free (filename);
}
g_dir_close (dir);
}
/**
* gst_registry_scan_path:
* @registry: the registry to add the path to
* @path: the path to add to the registry
*
* Add the given path to the registry. The syntax of the
* path is specific to the registry. If the path has already been
* added, do nothing.
*/
void
gst_registry_scan_path (GstRegistry * registry, const gchar * path)
{
GST_DEBUG_OBJECT (registry, "scanning path %s", path);
gst_registry_scan_path_level (registry, path, 10);
}
void
_gst_registry_remove_cache_plugins (GstRegistry * registry)
{
GList *g;
GList *g_next;
GstPlugin *plugin;
GST_DEBUG_OBJECT (registry, "removing cached plugins");
g = registry->plugins;
while (g) {
g_next = g->next;
plugin = g->data;
if (plugin->flags & GST_PLUGIN_FLAG_CACHED) {
GST_DEBUG_OBJECT (registry, "removing cached plugin \"%s\"",
GST_STR_NULL (plugin->filename));
registry->plugins = g_list_remove (registry->plugins, plugin);
gst_object_unref (plugin);
}
g = g_next;
}
}
static gboolean
_gst_plugin_feature_filter_plugin_name (GstPluginFeature * feature,
gpointer user_data)
{
return (strcmp (feature->plugin_name, (gchar *) user_data) == 0);
}
GList *
gst_registry_get_feature_list_by_plugin (GstRegistry * registry,
const gchar * name)
{
return gst_registry_feature_filter (registry,
_gst_plugin_feature_filter_plugin_name, FALSE, (gpointer) name);
}
void
_gst_registry_cleanup ()
{
if (!_gst_registry_default)
return;
gst_object_unref (_gst_registry_default);
_gst_registry_default = NULL;
}
/**
* gst_default_registry_check_feature_version:
* @feature_name: the name of the feature (e.g. "oggdemux")
* @min_major: the minimum major version number
* @min_minor: the minimum minor version number
* @min_micro: the minimum micro version number
*
* Checks whether a plugin feature by the given name exists in the
* default registry and whether its version is at least the
* version required.
*
* Returns: #TRUE if the feature could be found and the version is
* the same as the required version or newer, and #FALSE otherwise.
*/
gboolean
gst_default_registry_check_feature_version (const gchar * feature_name,
guint min_major, guint min_minor, guint min_micro)
{
GstPluginFeature *feature;
GstRegistry *registry;
gboolean ret = FALSE;
g_return_val_if_fail (feature_name != NULL, FALSE);
GST_DEBUG ("Looking up plugin feature '%s'", feature_name);
registry = gst_registry_get_default ();
feature = gst_registry_lookup_feature (registry, feature_name);
if (feature) {
ret = gst_plugin_feature_check_version (feature, min_major, min_minor,
min_micro);
gst_object_unref (feature);
} else {
GST_DEBUG ("Could not find plugin feature '%s'", feature_name);
}
return ret;
}