gstreamer/gst/gstelementfactory.c

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/* Gnome-Streamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
#include <gst/gstelement.h>
#include <gst/gstplugin.h>
/* global list of registered elementfactories */
GList* _gst_elementfactories;
void _gst_elementfactory_initialize() {
_gst_elementfactories = NULL;
}
/**
* gst_elementfactory_register:
* @elementfactory: factory to register
*
* Adds the elementfactory to the global list, so it can be retrieved by
* name.
*/
void gst_elementfactory_register(GstElementFactory *elementfactory) {
g_return_if_fail(elementfactory != NULL);
_gst_elementfactories = g_list_prepend(_gst_elementfactories,elementfactory);
}
/**
* 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(gchar *name) {
GList *walk;
GstElementFactory *factory;
gst_plugin_load_elementfactory(name);
walk = _gst_elementfactories;
while (walk) {
factory = (GstElementFactory *)(walk->data);
if (!strcmp(name,factory->name))
return factory;
walk = g_list_next(walk);
}
return NULL;
}
/**
* gst_elementfactory_get_list:
*
* Get the global list of elementfactories.
*
* Returns: <type>GList</type> of type #GstElementFactory
*/
GList *gst_elementfactory_get_list() {
return _gst_elementfactories;
}
/**
* gst_elementfactory_new:
* @name: name of new elementfactory
* @type: GtkType 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(gchar *name,GtkType type,
GstElementDetails *details) {
GstElementFactory *factory = g_new0(GstElementFactory, 1);
factory->name = g_strdup(name);
factory->type = type;
factory->details = details;
factory->src_types = NULL;
factory->sink_types = NULL;
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,
gchar *name) {
GstElement *element;
GstElementClass *oclass;
g_return_val_if_fail(factory != NULL, NULL);
factory = gst_plugin_load_elementfactory(factory->name);
if (factory->type == 0) {
factory = gst_elementfactory_find(name);
}
g_return_val_if_fail(factory->type != 0, NULL);
// create an instance of the element
element = GST_ELEMENT(gtk_type_new(factory->type));
g_assert(element != NULL);
gst_object_ref(GST_OBJECT(element));
// attempt to set the elemenfactory class pointer if necessary
oclass = GST_ELEMENT_CLASS(GTK_OBJECT(element)->klass);
if (oclass->elementfactory == NULL)
oclass->elementfactory = factory;
gst_element_set_name(GST_ELEMENT(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(gchar *factoryname,gchar *name) {
GstElementFactory *factory;
GstElement *element;
//gst_plugin_load_elementfactory(factoryname);
factory = gst_elementfactory_find(factoryname);
if (factory == NULL) return NULL;
element = gst_elementfactory_create(factory,name);
return element;
}
/**
* gst_elementfactory_add_src:
* @elementfactory: factory to add the src id to
* @id: the mime id of the src
*
* Use this function to indicate that this factory can src
* the given type id.
*/
void gst_elementfactory_add_src(GstElementFactory *elementfactory, guint16 id) {
guint type = id;
elementfactory->src_types = g_list_prepend(elementfactory->src_types, GUINT_TO_POINTER(type));
}
/**
* gst_elementfactory_add_sink:
* @elementfactory: factory to add the sink id to
* @id: the type id of the sink
*
* Use this function to indicate that this factory can sink
* the given type id.
*/
void gst_elementfactory_add_sink(GstElementFactory *elementfactory, guint16 id) {
guint type = id;
elementfactory->sink_types = g_list_prepend(elementfactory->sink_types, GUINT_TO_POINTER(type));
}
/**
* gst_elementfactory_save_thyself:
* @factory: factory to save
* @parent: the parent xmlNodePtr
*
* Saves the factory into an XML tree
*
* Returns: the new xmlNodePtr
*/
xmlNodePtr gst_elementfactory_save_thyself(GstElementFactory *factory, xmlNodePtr parent) {
GList *types;
xmlNodePtr subtree;
xmlNewChild(parent,NULL,"name",factory->name);
xmlNewChild(parent,NULL,"longname", factory->details->longname);
xmlNewChild(parent,NULL,"class", factory->details->class);
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);
types = factory->src_types;
if (types) {
subtree = xmlNewChild(parent,NULL,"sources",NULL);
while (types) {
guint16 typeid = GPOINTER_TO_UINT(types->data);
GstType *type = gst_type_find_by_id(typeid);
gst_type_save_thyself(type, subtree);
types = g_list_next(types);
}
}
types = factory->sink_types;
if (types) {
subtree = xmlNewChild(parent,NULL,"sinks",NULL);
while (types) {
guint16 typeid = GPOINTER_TO_UINT(types->data);
GstType *type = gst_type_find_by_id(typeid);
gst_type_save_thyself(type, subtree);
types = g_list_next(types);
}
}
return parent;
}
/**
* gst_elementfactory_load_thyself:
* @parent: the parent xmlNodePtr
*
* Creates a new factory from an xmlNodePtr
*
* Returns: the new factory
*/
GstElementFactory *gst_elementfactory_load_thyself(xmlNodePtr parent) {
GstElementFactory *factory = g_new0(GstElementFactory, 1);
xmlNodePtr children = parent->childs;
factory->details = g_new0(GstElementDetails, 1);
factory->sink_types = NULL;
factory->src_types = NULL;
while (children) {
if (!strcmp(children->name, "name")) {
factory->name = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "longname")) {
factory->details->longname = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "class")) {
factory->details->class = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "description")) {
factory->details->description = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "version")) {
factory->details->version = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "author")) {
factory->details->author = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "copyright")) {
factory->details->copyright = g_strdup(xmlNodeGetContent(children));
}
if (!strcmp(children->name, "sources")) {
guint16 typeid = gst_type_load_thyself(children);
gst_type_add_src(typeid, factory);
}
if (!strcmp(children->name, "sinks")) {
guint16 typeid = gst_type_load_thyself(children);
gst_type_add_sink(typeid, factory);
}
children = children->next;
}
return factory;
}