gstreamer/gst/gstpluginfeature.c

423 lines
11 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstpluginfeature.c: Abstract base class for all plugin features
*
* 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:gstpluginfeature
* @short_description: Base class for contents of a GstPlugin
* @see_also: #GstPlugin
*
* This is a base class for anything that can be added to a #GstPlugin.
*/
#include "gst_private.h"
#include "gstpluginfeature.h"
#include "gstplugin.h"
#include "gstregistry.h"
#include "gstinfo.h"
#include <stdio.h>
#include <string.h>
#define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING
static void gst_plugin_feature_finalize (GObject * object);
/* static guint gst_plugin_feature_signals[LAST_SIGNAL] = { 0 }; */
G_DEFINE_ABSTRACT_TYPE (GstPluginFeature, gst_plugin_feature, GST_TYPE_OBJECT);
static GstObjectClass *parent_class = NULL;
static void
gst_plugin_feature_class_init (GstPluginFeatureClass * klass)
{
parent_class = g_type_class_peek_parent (klass);
G_OBJECT_CLASS (klass)->finalize = gst_plugin_feature_finalize;
}
static void
gst_plugin_feature_init (GstPluginFeature * feature)
{
/* do nothing, needed because of G_DEFINE_TYPE */
}
static void
gst_plugin_feature_finalize (GObject * object)
{
GstPluginFeature *feature = GST_PLUGIN_FEATURE_CAST (object);
GST_DEBUG ("finalizing feature %p: '%s'", feature,
GST_PLUGIN_FEATURE_NAME (feature));
g_free (feature->name);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
/**
* gst_plugin_feature_load:
* @feature: the plugin feature to check
*
* Loads the plugin containing @feature if it's not already loaded. @feature is
* unaffected; use the return value instead.
*
* Normally this function is used like this:
* |[
* GstPluginFeature *loaded_feature;
*
* loaded_feature = gst_plugin_feature_load (feature);
* // presumably, we're no longer interested in the potentially-unloaded feature
* gst_object_unref (feature);
* feature = loaded_feature;
* ]|
*
* Returns: A reference to the loaded feature, or NULL on error.
*/
GstPluginFeature *
gst_plugin_feature_load (GstPluginFeature * feature)
{
GstPlugin *plugin;
GstPluginFeature *real_feature;
g_return_val_if_fail (feature != NULL, FALSE);
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);
GST_DEBUG ("loading plugin for feature %p; '%s'", feature,
GST_PLUGIN_FEATURE_NAME (feature));
if (feature->loaded)
return gst_object_ref (feature);
GST_DEBUG ("loading plugin %s", feature->plugin_name);
plugin = gst_plugin_load_by_name (feature->plugin_name);
if (!plugin)
goto load_failed;
GST_DEBUG ("loaded plugin %s", feature->plugin_name);
gst_object_unref (plugin);
real_feature =
gst_registry_lookup_feature (gst_registry_get_default (), feature->name);
if (real_feature == NULL)
goto disappeared;
else if (!real_feature->loaded)
goto not_found;
return real_feature;
/* ERRORS */
load_failed:
{
GST_WARNING ("Failed to load plugin containing feature '%s'.",
GST_PLUGIN_FEATURE_NAME (feature));
return NULL;
}
disappeared:
{
GST_INFO
("Loaded plugin containing feature '%s', but feature disappeared.",
feature->name);
return NULL;
}
not_found:
{
GST_INFO ("Tried to load plugin containing feature '%s', but feature was "
"not found.", real_feature->name);
return NULL;
}
}
/**
* gst_plugin_feature_type_name_filter:
* @feature: the #GstPluginFeature
* @data: the type and name to check against
*
* Compares type and name of plugin feature. Can be used with gst_filter_run().
*
* Returns: TRUE if equal.
*/
gboolean
gst_plugin_feature_type_name_filter (GstPluginFeature * feature,
GstTypeNameData * data)
{
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);
return ((data->type == 0 || data->type == G_OBJECT_TYPE (feature)) &&
(data->name == NULL
|| !strcmp (data->name, GST_PLUGIN_FEATURE_NAME (feature))));
}
/**
* gst_plugin_feature_set_name:
* @feature: a feature
* @name: the name to set
*
* Sets the name of a plugin feature. The name uniquely identifies a feature
* within all features of the same type. Renaming a plugin feature is not
* allowed. A copy is made of the name so you should free the supplied @name
* after calling this function.
*/
void
gst_plugin_feature_set_name (GstPluginFeature * feature, const gchar * name)
{
g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
g_return_if_fail (name != NULL);
if (feature->name) {
g_return_if_fail (strcmp (feature->name, name) == 0);
} else {
feature->name = g_strdup (name);
}
gst_object_set_name (GST_OBJECT_CAST (feature), feature->name);
}
/**
* gst_plugin_feature_get_name:
* @feature: a feature
*
* Gets the name of a plugin feature.
*
* Returns: the name
*/
G_CONST_RETURN gchar *
gst_plugin_feature_get_name (GstPluginFeature * feature)
{
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), NULL);
return feature->name;
}
/**
* gst_plugin_feature_set_rank:
* @feature: feature to rank
* @rank: rank value - higher number means more priority rank
*
* Specifies a rank for a plugin feature, so that autoplugging uses
* the most appropriate feature.
*/
void
gst_plugin_feature_set_rank (GstPluginFeature * feature, guint rank)
{
g_return_if_fail (feature != NULL);
g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
feature->rank = rank;
}
/**
* gst_plugin_feature_get_rank:
* @feature: a feature
*
* Gets the rank of a plugin feature.
*
* Returns: The rank of the feature
*/
guint
gst_plugin_feature_get_rank (GstPluginFeature * feature)
{
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), GST_RANK_NONE);
return feature->rank;
}
/**
* gst_plugin_feature_list_free:
* @list: list of #GstPluginFeature
*
* Unrefs each member of @list, then frees the list.
*/
void
gst_plugin_feature_list_free (GList * list)
{
GList *g;
for (g = list; g; g = g->next) {
GstPluginFeature *feature = GST_PLUGIN_FEATURE_CAST (g->data);
gst_object_unref (feature);
}
g_list_free (list);
}
/**
* gst_plugin_feature_list_copy:
* @list: list of #GstPluginFeature
*
* Copies the list of features. Caller should call @gst_plugin_feature_list_free
* when done with the list.
*
* Returns: a copy of @list, with each feature's reference count incremented.
*
* Since: 0.10.26
*/
GList *
gst_plugin_feature_list_copy (GList * list)
{
GList *new_list = NULL;
if (G_LIKELY (list)) {
GList *last;
new_list = g_list_alloc ();
new_list->data = g_object_ref ((GObject *) list->data);
new_list->prev = NULL;
last = new_list;
list = list->next;
while (list) {
last->next = g_list_alloc ();
last->next->prev = last;
last = last->next;
last->data = g_object_ref ((GObject *) list->data);
list = list->next;
}
last->next = NULL;
}
return new_list;
}
/**
* gst_plugin_feature_list_debug:
* @list: a #GList of plugin features
*
* Debug the plugin feature names in @list.
*
* Since: 0.10.31
*/
void
gst_plugin_feature_list_debug (GList * list)
{
#ifndef GST_DISABLE_GST_DEBUG
while (list) {
GST_DEBUG ("%s",
gst_plugin_feature_get_name ((GstPluginFeature *) list->data));
list = list->next;
}
#endif
}
/**
* gst_plugin_feature_check_version:
* @feature: a feature
* @min_major: minimum required major version
* @min_minor: minimum required minor version
* @min_micro: minimum required micro version
*
* Checks whether the given plugin feature is at least
* the required version
*
* Returns: #TRUE if the plugin feature has at least
* the required version, otherwise #FALSE.
*/
gboolean
gst_plugin_feature_check_version (GstPluginFeature * feature,
guint min_major, guint min_minor, guint min_micro)
{
GstRegistry *registry;
GstPlugin *plugin;
gboolean ret = FALSE;
g_return_val_if_fail (feature != NULL, FALSE);
g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);
GST_DEBUG ("Looking up plugin '%s' containing plugin feature '%s'",
feature->plugin_name, feature->name);
registry = gst_registry_get_default ();
plugin = gst_registry_find_plugin (registry, feature->plugin_name);
if (plugin) {
const gchar *ver_str;
guint major, minor, micro, nano;
gint nscan;
ver_str = gst_plugin_get_version (plugin);
g_return_val_if_fail (ver_str != NULL, FALSE);
nscan = sscanf (ver_str, "%u.%u.%u.%u", &major, &minor, &micro, &nano);
GST_DEBUG ("version string '%s' parsed to %d values", ver_str, nscan);
if (nscan >= 3) {
if (major > min_major)
ret = TRUE;
else if (major < min_major)
ret = FALSE;
else if (minor > min_minor)
ret = TRUE;
else if (minor < min_minor)
ret = FALSE;
else if (micro > min_micro)
ret = TRUE;
/* micro is 1 smaller but we have a nano version, this is the upcomming
* release of the requested version and we're ok then */
else if (nscan == 4 && nano > 0 && (micro + 1 == min_micro))
ret = TRUE;
else
ret = (micro == min_micro);
GST_DEBUG ("Checking whether %u.%u.%u >= %u.%u.%u? %s", major, minor,
micro, min_major, min_minor, min_micro, (ret) ? "yes" : "no");
} else {
GST_WARNING ("Could not parse version string '%s' of plugin '%s'",
ver_str, feature->plugin_name);
}
gst_object_unref (plugin);
} else {
GST_DEBUG ("Could not find plugin '%s'", feature->plugin_name);
}
return ret;
}
/**
* gst_plugin_feature_rank_compare_func:
* @p1: a #GstPluginFeature
* @p2: a #GstPluginFeature
*
* Compares the two given #GstPluginFeature instances. This function can be
* used as a #GCompareFunc when sorting by rank and then by name.
*
* Returns: negative value if the rank of p1 > the rank of p2 or the ranks are
* equal but the name of p1 comes before the name of p2; zero if the rank
* and names are equal; positive value if the rank of p1 < the rank of p2 or the
* ranks are equal but the name of p2 comes after the name of p1
*
* Since: 0.10.31
*/
gint
gst_plugin_feature_rank_compare_func (gconstpointer p1, gconstpointer p2)
{
GstPluginFeature *f1, *f2;
gint diff;
f1 = (GstPluginFeature *) p1;
f2 = (GstPluginFeature *) p2;
diff = f2->rank - f1->rank;
if (diff != 0)
return diff;
diff = strcmp (f2->name, f1->name);
return diff;
}