gstreamer/gst/gstelementfactory.c
Wim Taymans 12bbbd5c1e Lots of modifications to the plugin system.
Original commit message from CVS:
Lots of modifications to the plugin system.
- Added a GstPluginfeature object that serves as a base class for all
plugin contents.
- changed the plugin API, everyhting is now added with
gst_plugin_add_feature
- typefactories are named now so that they can be located easily and filled
in at plugin load.
- mime types like "video/raw image/raw" are gone for now.
- lots of plugin updates (style and API changes)
- tested with an without registry.
- updates to various tools.
- added a little testsuite to test/show how you can load plugins (4 modes)

Test this one, Almost everything has changed :-)
2001-08-21 20:16:48 +00:00

444 lines
12 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* 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.
*/
//#define DEBUG_ENABLED
#include "gst_private.h"
#include "gstelement.h"
static void gst_elementfactory_class_init (GstElementFactoryClass *klass);
static void gst_elementfactory_init (GstElementFactory *factory);
static void gst_elementfactory_restore_thyself (GstObject *object, xmlNodePtr parent);
static xmlNodePtr gst_elementfactory_save_thyself (GstObject *object, xmlNodePtr parent);
static void gst_elementfactory_unload_thyself (GstPluginFeature *feature);
/* global list of registered elementfactories */
static GList* _gst_elementfactories;
static GstPluginFeatureClass *parent_class = NULL;
//static guint gst_elementfactory_signals[LAST_SIGNAL] = { 0 };
GType
gst_elementfactory_get_type (void)
{
static GType elementfactory_type = 0;
if (!elementfactory_type) {
static const GTypeInfo elementfactory_info = {
sizeof (GstElementFactoryClass),
NULL,
NULL,
(GClassInitFunc) gst_elementfactory_class_init,
NULL,
NULL,
sizeof(GstElementFactory),
0,
(GInstanceInitFunc) gst_elementfactory_init,
};
elementfactory_type = g_type_register_static (GST_TYPE_PLUGIN_FEATURE,
"GstElementFactory", &elementfactory_info, 0);
}
return elementfactory_type;
}
static void
gst_elementfactory_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_ref (GST_TYPE_PLUGIN_FEATURE);
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_elementfactory_save_thyself);
gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR (gst_elementfactory_restore_thyself);
gstpluginfeature_class->unload_thyself = GST_DEBUG_FUNCPTR (gst_elementfactory_unload_thyself);
_gst_elementfactories = NULL;
}
static void
gst_elementfactory_init (GstElementFactory *factory)
{
factory->padtemplates = NULL;
factory->numpadtemplates = 0;
_gst_elementfactories = g_list_prepend (_gst_elementfactories, factory);
}
/**
* gst_elementfactory_find:
* @name: name of factory to find
*
* Search for an elementfactory of the given name.
*
* Returns: #GstElementFactory if found, NULL otherwise
*/
GstElementFactory*
gst_elementfactory_find (const gchar *name)
{
GList *walk;
GstElementFactory *factory;
g_return_val_if_fail(name != NULL, NULL);
walk = _gst_elementfactories;
while (walk) {
factory = (GstElementFactory *)(walk->data);
if (!strcmp(name, GST_OBJECT_NAME (factory)))
return factory;
walk = g_list_next(walk);
}
// this should be an ERROR
GST_DEBUG (GST_CAT_ELEMENTFACTORY,"no such elementfactory \"%s\"\n", name);
return NULL;
}
/**
* gst_elementfactory_get_list:
*
* Get the global list of elementfactories.
*
* Returns: GList of type #GstElementFactory
*/
const GList*
gst_elementfactory_get_list (void)
{
return _gst_elementfactories;
}
/**
* gst_elementfactory_new:
* @name: name of new elementfactory
* @type: GType of new element
* @details: #GstElementDetails structure with element details
*
* Create a new elementfactory capable of insantiating objects of the
* given type.
*
* Returns: new elementfactory
*/
GstElementFactory*
gst_elementfactory_new (const gchar *name, GType type,
GstElementDetails *details)
{
GstElementFactory *factory;
g_return_val_if_fail(name != NULL, NULL);
g_return_val_if_fail(type != 0, NULL);
factory = gst_elementfactory_find (name);
if (!factory) {
factory = GST_ELEMENTFACTORY (g_object_new (GST_TYPE_ELEMENTFACTORY, NULL));
}
gst_object_set_name (GST_OBJECT (factory), name);
factory->type = type;
if (factory->details)
g_free (factory->details);
factory->details = details;
return factory;
}
/**
* gst_elementfactory_create:
* @factory: factory to instantiate
* @name: name of new element
*
* Create a new element of the type defined by the given elementfactory.
* It wll be given the name supplied, since all elements require a name as
* their first argument.
*
* Returns: new #GstElement
*/
GstElement *
gst_elementfactory_create (GstElementFactory *factory,
const gchar *name)
{
GstElement *element;
GstElementClass *oclass;
g_return_val_if_fail(factory != NULL, NULL);
g_return_val_if_fail(name != NULL, NULL);
GST_DEBUG (GST_CAT_ELEMENTFACTORY,"creating element from factory \"%s\" with name \"%s\"\n",
GST_OBJECT_NAME (factory), name);
gst_plugin_feature_ensure_loaded (GST_PLUGIN_FEATURE (factory));
g_return_val_if_fail(factory->type != 0, NULL);
// create an instance of the element
element = GST_ELEMENT(g_object_new(factory->type,NULL));
g_assert(element != NULL);
// attempt to set the elemenfactory class pointer if necessary
oclass = GST_ELEMENT_CLASS(G_OBJECT_GET_CLASS(element));
if (oclass->elementfactory == NULL) {
GST_DEBUG (GST_CAT_ELEMENTFACTORY,"class %s\n", GST_OBJECT_NAME (factory));
oclass->elementfactory = factory;
}
// copy pad template pointers to the element class
oclass->padtemplates = g_list_copy(factory->padtemplates);
oclass->numpadtemplates = factory->numpadtemplates;
gst_object_set_name (GST_OBJECT (element),name);
return element;
}
/**
* gst_elementfactory_make:
* @factoryname: a named factory to instantiate
* @name: name of new element
*
* Create a new element of the type defined by the given elementfactory.
* It wll be given the name supplied, since all elements require a name as
* their first argument.
*
* Returns: new #GstElement
*/
GstElement*
gst_elementfactory_make (const gchar *factoryname, const gchar *name)
{
GstElementFactory *factory;
GstElement *element;
g_return_val_if_fail (factoryname != NULL, NULL);
g_return_val_if_fail (name != NULL, NULL);
GST_DEBUG (GST_CAT_ELEMENTFACTORY, "gstelementfactory: make \"%s\" \"%s\"\n", factoryname, name);
//gst_plugin_load_elementfactory(factoryname);
factory = gst_elementfactory_find(factoryname);
if (factory == NULL) {
GST_INFO (GST_CAT_ELEMENTFACTORY,"no such elementfactory \"%s\"!",factoryname);
return NULL;
}
element = gst_elementfactory_create(factory,name);
if (element == NULL) {
GST_INFO (GST_CAT_ELEMENTFACTORY,"couldn't create instance of elementfactory \"%s\"!",factoryname);
return NULL;
}
return element;
}
/**
* gst_elementfactory_add_padtemplate :
* @elementfactory: factory to add the src id to
* @templ: the padtemplate to add
*
* Add the given padtemplate to this elementfactory.
*/
void
gst_elementfactory_add_padtemplate (GstElementFactory *factory,
GstPadTemplate *templ)
{
GList *padtemplates;
g_return_if_fail(factory != NULL);
g_return_if_fail(templ != NULL);
padtemplates = factory->padtemplates;
while (padtemplates) {
GstPadTemplate *oldtempl = GST_PADTEMPLATE (padtemplates->data);
if (!strcmp (oldtempl->name_template, templ->name_template)) {
gst_object_unref (GST_OBJECT (oldtempl));
padtemplates->data = templ;
return;
}
padtemplates = g_list_next (padtemplates);
}
factory->padtemplates = g_list_append (factory->padtemplates, templ);
factory->numpadtemplates++;
}
/**
* gst_elementfactory_can_src_caps :
* @factory: factory to query
* @caps: the caps to check
*
* Checks if the factory can source the given capability.
*
* Returns: true if it can src the capabilities
*/
gboolean
gst_elementfactory_can_src_caps (GstElementFactory *factory,
GstCaps *caps)
{
GList *templates;
g_return_val_if_fail(factory != NULL, FALSE);
g_return_val_if_fail(caps != NULL, FALSE);
templates = factory->padtemplates;
while (templates) {
GstPadTemplate *template = (GstPadTemplate *)templates->data;
if (template->direction == GST_PAD_SRC) {
if (gst_caps_check_compatibility (GST_PADTEMPLATE_CAPS (template), caps))
return TRUE;
}
templates = g_list_next (templates);
}
return FALSE;
}
/**
* gst_elementfactory_can_sink_caps :
* @factory: factory to query
* @caps: the caps to check
*
* Checks if the factory can sink the given capability.
*
* Returns: true if it can sink the capabilities
*/
gboolean
gst_elementfactory_can_sink_caps (GstElementFactory *factory,
GstCaps *caps)
{
GList *templates;
g_return_val_if_fail(factory != NULL, FALSE);
g_return_val_if_fail(caps != NULL, FALSE);
templates = factory->padtemplates;
while (templates) {
GstPadTemplate *template = (GstPadTemplate *)templates->data;
if (template->direction == GST_PAD_SINK) {
if (gst_caps_check_compatibility (caps, GST_PADTEMPLATE_CAPS (template)))
return TRUE;
}
templates = g_list_next (templates);
}
return FALSE;
}
static void
gst_elementfactory_unload_thyself (GstPluginFeature *feature)
{
GstElementFactory *factory;
factory = GST_ELEMENTFACTORY (feature);
factory->type = 0;
}
static xmlNodePtr
gst_elementfactory_save_thyself (GstObject *object,
xmlNodePtr parent)
{
GList *pads;
GstElementFactory *factory;
factory = GST_ELEMENTFACTORY (object);
if (GST_OBJECT_CLASS (parent_class)->save_thyself) {
GST_OBJECT_CLASS (parent_class)->save_thyself (object, parent);
}
g_return_val_if_fail(factory != NULL, NULL);
xmlNewChild(parent,NULL,"longname", factory->details->longname);
xmlNewChild(parent,NULL,"class", factory->details->klass);
xmlNewChild(parent,NULL,"description", factory->details->description);
xmlNewChild(parent,NULL,"version", factory->details->version);
xmlNewChild(parent,NULL,"author", factory->details->author);
xmlNewChild(parent,NULL,"copyright", factory->details->copyright);
pads = factory->padtemplates;
if (pads) {
while (pads) {
xmlNodePtr subtree;
GstPadTemplate *padtemplate = (GstPadTemplate *)pads->data;
subtree = xmlNewChild(parent, NULL, "padtemplate", NULL);
gst_padtemplate_save_thyself(padtemplate, subtree);
pads = g_list_next (pads);
}
}
return parent;
}
static void
gst_elementfactory_restore_thyself (GstObject *object, xmlNodePtr parent)
{
GstElementFactory *factory = GST_ELEMENTFACTORY (object);
xmlNodePtr children = parent->xmlChildrenNode;
factory->details = g_new0(GstElementDetails, 1);
factory->padtemplates = NULL;
if (GST_OBJECT_CLASS (parent_class)->restore_thyself) {
GST_OBJECT_CLASS (parent_class)->restore_thyself (object, parent);
}
while (children) {
if (!strcmp(children->name, "longname")) {
factory->details->longname = xmlNodeGetContent(children);
}
if (!strcmp(children->name, "class")) {
factory->details->klass = xmlNodeGetContent(children);
}
if (!strcmp(children->name, "description")) {
factory->details->description = xmlNodeGetContent(children);
}
if (!strcmp(children->name, "version")) {
factory->details->version = xmlNodeGetContent(children);
}
if (!strcmp(children->name, "author")) {
factory->details->author = xmlNodeGetContent(children);
}
if (!strcmp(children->name, "copyright")) {
factory->details->copyright = xmlNodeGetContent(children);
}
if (!strcmp(children->name, "padtemplate")) {
GstPadTemplate *template;
template = gst_padtemplate_load_thyself (children);
gst_elementfactory_add_padtemplate (factory, template);
}
children = children->next;
}
}