gstreamer/gst/gstxml.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstxml.c: XML save/restore of pipelines
*
* 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_private.h"
#include "gstxml.h"
static void gst_xml_class_init (GstXMLClass *klass);
static void gst_xml_init (GstXML *xml);
static GstObjectClass *parent_class = NULL;
GtkType
gst_xml_get_type(void)
{
static GtkType xml_type = 0;
if (!xml_type) {
static const GtkTypeInfo xml_info = {
"GstXML",
sizeof(GstElement),
sizeof(GstElementClass),
(GtkClassInitFunc)gst_xml_class_init,
(GtkObjectInitFunc)gst_xml_init,
(GtkArgSetFunc)NULL,
(GtkArgGetFunc)NULL,
(GtkClassInitFunc)NULL,
};
xml_type = gtk_type_unique (GST_TYPE_XML, &xml_info);
}
return xml_type;
}
static void
gst_xml_class_init (GstXMLClass *klass)
{
parent_class = gtk_type_class (GST_TYPE_OBJECT);
}
static void
gst_xml_init(GstXML *xml)
{
}
/**
* gst_xml_write:
* @element: The element to write out
*
* converts the given element into an XML presentation
*
* Returns: a pointer to an XML document
*/
xmlDocPtr
gst_xml_write (GstElement *element)
{
xmlDocPtr doc;
doc = xmlNewDoc ("1.0");
doc->root = xmlNewDocNode (doc, NULL, "GST-Pipeline", NULL);
gst_element_save_thyself (element, doc->root);
return doc;
}
/**
* gst_xml_new:
* @fname: The filename with the xml description
* @root: The name of the root object to build
*
* Creates a new GstXML object (and the corresponding elements) from
* the XML file fname. Optionally it will only build the element from
* the element node root (if it is not NULL). This feature is useful
* if you only want to build a specific element from an XML file
* but not the pipeline it is embedded in. Note also that the XML parse
* tree is cached to speed up creating another GstXML object for
* the same file
*
* Returns: a pointer to a new GstElement
*/
GstXML*
gst_xml_new (const guchar *fname, const guchar *root)
{
xmlDocPtr doc;
xmlNodePtr field;
GstXML *xml;
g_return_val_if_fail(fname != NULL, NULL);
doc = xmlParseFile(fname);
if (!doc) {
g_print("gstxml: XML file \"%s\" could not be read\n", fname);
return NULL;
}
if (strcmp(doc->root->name, "GST-Pipeline")) {
g_print("gstxml: XML file \"%s\" is in wrong format\n", fname);
return NULL;
}
xml = GST_XML(gtk_type_new(GST_TYPE_XML));
xml->topelements = NULL;
field = doc->root->childs;
while (field) {
if (!strcmp(field->name, "element")) {
GstElement *element;
xml->elements = g_hash_table_new(g_str_hash, g_str_equal);
element = gst_element_load_thyself(field, xml->elements);
g_hash_table_destroy (xml->elements);
xml->topelements = g_list_prepend (xml->topelements, element);
}
field = field->next;
}
xml->topelements = g_list_reverse (xml->topelements);
return xml;
}
/**
* gst_xml_get_topelements:
* @xml: The GstXML to get the elements from
*
* retrive a list of toplevel elements
*
* Returns: a GList of elements
*/
GList*
gst_xml_get_topelements (GstXML *xml)
{
g_return_val_if_fail (xml != NULL, NULL);
return xml->topelements;
}
/**
* gst_xml_get_element:
* @xml: The GstXML to get the element from
* @name: The name of element to retreive
*
* This function is used to get a pointer to the GstElement corresponding
* to name in the pipeline description. You would use this if you have
* to do anything to the element after loading.
*
* Returns: a pointer to a new GstElement
*/
GstElement*
gst_xml_get_element (GstXML *xml, const guchar *name)
{
GstElement *element;
g_return_val_if_fail(xml != NULL, NULL);
g_return_val_if_fail(name != NULL, NULL);
GST_DEBUG (0,"gstxml: getting element \"%s\"\n", name);
element = g_hash_table_lookup(xml->elements, name);
return element;
}