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00697e8529
Add a minimal gst_xml_get_type() function, so that gobject-introspection doesn't break the compilation if we're compiling with GST_REMOVE_DEPRECATED defined or --disable-loadsave having been passed to configure. Until someone figures out a better way at least.
541 lines
14 KiB
C
541 lines
14 KiB
C
/* GStreamer
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* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
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* 2000 Wim Taymans <wtay@chello.be>
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*
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* gstxml.c: XML save/restore of pipelines
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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/**
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* SECTION:gstxml
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* @short_description: XML save/restore operations of pipelines
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*
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* GStreamer pipelines can be saved to xml files using gst_xml_write_file().
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* They can be loaded back using gst_xml_parse_doc() / gst_xml_parse_file() /
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* gst_xml_parse_memory().
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* Additionally one can load saved pipelines into the gst-editor to inspect the
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* graph.
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*
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* #GstElement implementations need to override the #GstObjectClass.save_thyself()
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* and #GstObjectClass.restore_thyself() virtual functions of #GstObject.
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*
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* Deprecated: This feature is deprecated pipeline serialization to XML is
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* broken for all but the most simple pipelines. It will most likely be
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* removed in future. Don't use it.
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*/
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#include "gst_private.h"
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#include "gstxml.h"
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#include "gstmarshal.h"
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#include "gstinfo.h"
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#include "gstbin.h"
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#ifdef GST_DISABLE_DEPRECATED
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#if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
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#include <libxml/parser.h>
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xmlNodePtr gst_object_save_thyself (const GstObject * object,
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xmlNodePtr parent);
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GstObject *gst_object_load_thyself (xmlNodePtr parent);
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void gst_object_restore_thyself (GstObject * object, GstXmlNodePtr self);
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#define GST_TYPE_XML (gst_xml_get_type ())
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#define GST_XML(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_XML, GstXML))
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#define GST_IS_XML(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_XML))
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#define GST_XML_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_XML, GstXMLClass))
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#define GST_IS_XML_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_XML))
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#define GST_XML_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_XML, GstXMLClass))
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typedef struct _GstXML GstXML;
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typedef struct _GstXMLClass GstXMLClass;
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struct _GstXML
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{
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GstObject object;
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/*< public > */
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GList *topelements;
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xmlNsPtr ns;
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/*< private > */
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gpointer _gst_reserved[GST_PADDING];
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};
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struct _GstXMLClass
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{
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GstObjectClass parent_class;
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/* signal callbacks */
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void (*object_loaded) (GstXML * xml, GstObject * object, xmlNodePtr self);
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void (*object_saved) (GstXML * xml, GstObject * object, xmlNodePtr self);
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gpointer _gst_reserved[GST_PADDING];
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};
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GType gst_xml_get_type (void);
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xmlDocPtr gst_xml_write (GstElement * element);
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gint gst_xml_write_file (GstElement * element, FILE * out);
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GstXML *gst_xml_new (void);
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gboolean gst_xml_parse_doc (GstXML * xml, xmlDocPtr doc, const guchar * root);
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gboolean gst_xml_parse_file (GstXML * xml, const guchar * fname,
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const guchar * root);
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gboolean gst_xml_parse_memory (GstXML * xml, guchar * buffer, guint size,
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const gchar * root);
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GstElement *gst_xml_get_element (GstXML * xml, const guchar * name);
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GList *gst_xml_get_topelements (GstXML * xml);
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GstElement *gst_xml_make_element (xmlNodePtr cur, GstObject * parent);
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#endif
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#endif
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#if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
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enum
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{
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OBJECT_LOADED,
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LAST_SIGNAL
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};
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static void gst_xml_dispose (GObject * object);
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static void gst_xml_object_loaded (GstObject * private, GstObject * object,
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xmlNodePtr self, gpointer data);
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static GstObjectClass *parent_class = NULL;
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static guint gst_xml_signals[LAST_SIGNAL] = { 0 };
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G_DEFINE_TYPE (GstXML, gst_xml, GST_TYPE_OBJECT);
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static void
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gst_xml_class_init (GstXMLClass * klass)
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{
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GObjectClass *gobject_class = (GObjectClass *) klass;
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parent_class = g_type_class_peek_parent (klass);
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gobject_class->dispose = gst_xml_dispose;
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/* FIXME G_TYPE_POINTER should be GType of xmlNodePtr
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* (ensonic) can't be fixed, as libxml does not use GObject (unfortunately)
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*/
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/**
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* GstXML::object-loaded:
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* @xml: the xml persistence instance
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* @object: the object that has been loaded
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* @xml_node: the related xml_node pointer to the document tree
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*
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* Signals that a new object has been deserialized.
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*/
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gst_xml_signals[OBJECT_LOADED] =
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g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass),
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G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstXMLClass, object_loaded), NULL,
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NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
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G_TYPE_POINTER);
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}
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static void
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gst_xml_init (GstXML * xml)
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{
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xml->topelements = NULL;
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}
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static void
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gst_xml_dispose (GObject * object)
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{
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GstXML *xml = GST_XML (object);
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g_list_foreach (xml->topelements, (GFunc) gst_object_unref, NULL);
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g_list_free (xml->topelements);
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xml->topelements = NULL;
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G_OBJECT_CLASS (parent_class)->dispose (object);
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}
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/**
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* gst_xml_new:
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*
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* Create a new GstXML parser object.
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*
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* Returns: a pointer to a new GstXML object.
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*/
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GstXML *
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gst_xml_new (void)
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{
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return GST_XML (g_object_newv (GST_TYPE_XML, 0, NULL));
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}
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/**
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* gst_xml_write:
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* @element: The element to write out
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*
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* Converts the given element into an XML presentation.
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*
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* Returns: a pointer to an XML document
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*/
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xmlDocPtr
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gst_xml_write (GstElement * element)
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{
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xmlDocPtr doc;
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xmlNodePtr elementnode;
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xmlNsPtr gst_ns;
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doc = xmlNewDoc ((xmlChar *) "1.0");
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doc->xmlRootNode = xmlNewDocNode (doc, NULL, (xmlChar *) "gstreamer", NULL);
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gst_ns =
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xmlNewNs (doc->xmlRootNode,
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(xmlChar *) "http://gstreamer.net/gst-core/1.0/", (xmlChar *) "gst");
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elementnode = xmlNewChild (doc->xmlRootNode, gst_ns, (xmlChar *) "element",
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NULL);
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gst_object_save_thyself (GST_OBJECT (element), elementnode);
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return doc;
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}
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/**
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* gst_xml_write_file:
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* @element: The element to write out
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* @out: an open file, like stdout
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*
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* Converts the given element into XML and writes the formatted XML to an open
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* file.
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*
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* Returns: number of bytes written on success, -1 otherwise.
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*/
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gint
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gst_xml_write_file (GstElement * element, FILE * out)
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{
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xmlDocPtr cur;
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#ifdef HAVE_LIBXML2
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xmlOutputBufferPtr buf;
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#endif
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const char *encoding;
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xmlCharEncodingHandlerPtr handler = NULL;
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int indent;
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gboolean ret;
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cur = gst_xml_write (element);
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if (!cur)
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return -1;
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#ifdef HAVE_LIBXML2
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encoding = (const char *) cur->encoding;
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if (encoding != NULL) {
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xmlCharEncoding enc;
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enc = xmlParseCharEncoding (encoding);
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if (cur->charset != XML_CHAR_ENCODING_UTF8) {
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xmlGenericError (xmlGenericErrorContext,
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"xmlDocDump: document not in UTF8\n");
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return -1;
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}
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if (enc != XML_CHAR_ENCODING_UTF8) {
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handler = xmlFindCharEncodingHandler (encoding);
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if (handler == NULL) {
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xmlFree ((char *) cur->encoding);
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cur->encoding = NULL;
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}
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}
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}
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buf = xmlOutputBufferCreateFile (out, handler);
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indent = xmlIndentTreeOutput;
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xmlIndentTreeOutput = 1;
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ret = xmlSaveFormatFileTo (buf, cur, NULL, 1);
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xmlIndentTreeOutput = indent;
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#else
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/* apparently this doesn't return anything in libxml1 */
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xmlDocDump (out, cur);
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ret = 1;
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#endif
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return ret;
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}
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/**
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* gst_xml_parse_doc:
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* @xml: a pointer to a GstXML object
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* @doc: a pointer to an xml document to parse
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* @root: The name of the root object to build
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*
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* Fills the GstXML object with the elements from the
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* xmlDocPtr.
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*
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* Returns: TRUE on success, FALSE otherwise
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*/
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gboolean
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gst_xml_parse_doc (GstXML * xml, xmlDocPtr doc, const guchar * root)
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{
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xmlNodePtr field, cur;
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xmlNsPtr ns;
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cur = xmlDocGetRootElement (doc);
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if (cur == NULL) {
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g_warning ("gstxml: empty document\n");
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return FALSE;
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}
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ns = xmlSearchNsByHref (doc, cur,
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(xmlChar *) "http://gstreamer.net/gst-core/1.0/");
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if (ns == NULL) {
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g_warning ("gstxml: document of wrong type, core namespace not found\n");
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return FALSE;
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}
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if (strcmp ((char *) cur->name, "gstreamer")) {
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g_warning ("gstxml: XML file is in wrong format\n");
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return FALSE;
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}
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gst_class_signal_connect (GST_OBJECT_CLASS (G_OBJECT_GET_CLASS (xml)),
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"object_loaded", (gpointer) gst_xml_object_loaded, xml);
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xml->ns = ns;
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field = cur->xmlChildrenNode;
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while (field) {
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if (!strcmp ((char *) field->name, "element") && (field->ns == xml->ns)) {
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GstElement *element;
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element = gst_xml_make_element (field, NULL);
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xml->topelements = g_list_prepend (xml->topelements, element);
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}
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field = field->next;
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}
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xml->topelements = g_list_reverse (xml->topelements);
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return TRUE;
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}
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/* FIXME 0.9: Why guchar*? */
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/**
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* gst_xml_parse_file:
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* @xml: a pointer to a GstXML object
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* @fname: The filename with the xml description
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* @root: The name of the root object to build
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*
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* Fills the GstXML object with the corresponding elements from
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* the XML file fname. Optionally it will only build the element from
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* the element node root (if it is not NULL). This feature is useful
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* if you only want to build a specific element from an XML file
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* but not the pipeline it is embedded in.
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*
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* Pass "-" as fname to read from stdin. You can also pass a URI
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* of any format that libxml supports, including http.
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*
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* Returns: TRUE on success, FALSE otherwise
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*/
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gboolean
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gst_xml_parse_file (GstXML * xml, const guchar * fname, const guchar * root)
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{
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xmlDocPtr doc;
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gboolean ret;
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g_return_val_if_fail (fname != NULL, FALSE);
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doc = xmlParseFile ((char *) fname);
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if (!doc) {
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g_warning ("gstxml: XML file \"%s\" could not be read\n", fname);
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return FALSE;
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}
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ret = gst_xml_parse_doc (xml, doc, root);
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xmlFreeDoc (doc);
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return ret;
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}
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/* FIXME 0.9: guchar* */
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/**
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* gst_xml_parse_memory:
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* @xml: a pointer to a GstXML object
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* @buffer: a pointer to the in memory XML buffer
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* @size: the size of the buffer
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* @root: the name of the root objects to build
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*
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* Fills the GstXML object with the corresponding elements from
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* an in memory XML buffer.
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*
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* Returns: TRUE on success
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*/
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gboolean
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gst_xml_parse_memory (GstXML * xml, guchar * buffer, guint size,
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const gchar * root)
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{
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xmlDocPtr doc;
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gboolean ret;
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g_return_val_if_fail (buffer != NULL, FALSE);
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doc = xmlParseMemory ((char *) buffer, size);
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ret = gst_xml_parse_doc (xml, doc, (const xmlChar *) root);
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xmlFreeDoc (doc);
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return ret;
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}
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static void
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gst_xml_object_loaded (GstObject * private, GstObject * object, xmlNodePtr self,
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gpointer data)
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{
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GstXML *xml = GST_XML (data);
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/* FIXME check that this element was created from the same xmlDocPtr... */
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g_signal_emit (xml, gst_xml_signals[OBJECT_LOADED], 0, object, self);
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}
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/**
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* gst_xml_get_topelements:
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* @xml: The GstXML to get the elements from
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*
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* Retrieve a list of toplevel elements.
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*
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* Returns: a GList of top-level elements. The caller does not own a copy
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* of the list and must not free or modify the list. The caller also does not
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* own a reference to any of the elements in the list and should obtain its own
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* reference using gst_object_ref() if necessary.
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*/
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GList *
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gst_xml_get_topelements (GstXML * xml)
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{
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g_return_val_if_fail (xml != NULL, NULL);
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return xml->topelements;
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}
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/* FIXME 0.11: why is the arg guchar* instead of gchar*? */
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/**
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* gst_xml_get_element:
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* @xml: The GstXML to get the element from
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* @name: The name of element to retrieve
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*
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* This function is used to get a pointer to the GstElement corresponding
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* to name in the pipeline description. You would use this if you have
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* to do anything to the element after loading.
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*
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* Returns: a pointer to a new GstElement, caller owns returned reference.
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*/
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GstElement *
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gst_xml_get_element (GstXML * xml, const guchar * name)
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{
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GstElement *element;
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GList *topelements;
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g_return_val_if_fail (xml != NULL, NULL);
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g_return_val_if_fail (name != NULL, NULL);
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GST_DEBUG ("gstxml: getting element \"%s\"", name);
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topelements = gst_xml_get_topelements (xml);
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while (topelements) {
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GstElement *top = GST_ELEMENT (topelements->data);
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GST_DEBUG ("gstxml: getting element \"%s\"", name);
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if (!strcmp (GST_ELEMENT_NAME (top), (char *) name)) {
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return GST_ELEMENT_CAST (gst_object_ref (top));
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} else {
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if (GST_IS_BIN (top)) {
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element = gst_bin_get_by_name (GST_BIN (top), (gchar *) name);
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if (element)
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return element;
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}
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}
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topelements = g_list_next (topelements);
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}
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return NULL;
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}
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/**
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* gst_xml_make_element:
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* @cur: the xml node
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* @parent: the parent of this object when it's loaded
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*
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* Load the element from the XML description
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*
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* Returns: the new element
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*/
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GstElement *
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gst_xml_make_element (xmlNodePtr cur, GstObject * parent)
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{
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xmlNodePtr children = cur->xmlChildrenNode;
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GstElement *element;
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gchar *name = NULL;
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gchar *type = NULL;
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/* first get the needed tags to construct the element */
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while (children) {
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if (!strcmp ((char *) children->name, "name")) {
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name = (gchar *) xmlNodeGetContent (children);
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} else if (!strcmp ((char *) children->name, "type")) {
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type = (gchar *) xmlNodeGetContent (children);
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}
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children = children->next;
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}
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g_return_val_if_fail (name != NULL, NULL);
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g_return_val_if_fail (type != NULL, NULL);
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GST_CAT_INFO (GST_CAT_XML, "loading \"%s\" of type \"%s\"", name, type);
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element = gst_element_factory_make (type, name);
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g_return_val_if_fail (element != NULL, NULL);
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g_free (type);
|
|
g_free (name);
|
|
|
|
/* ne need to set the parent on this object bacause the pads */
|
|
/* will go through the hierarchy to link to their peers */
|
|
if (parent) {
|
|
if (GST_IS_BIN (parent)) {
|
|
gst_bin_add (GST_BIN (parent), element);
|
|
} else {
|
|
gst_object_set_parent (GST_OBJECT (element), parent);
|
|
}
|
|
}
|
|
|
|
gst_object_restore_thyself (GST_OBJECT (element), cur);
|
|
|
|
return element;
|
|
}
|
|
|
|
#else
|
|
|
|
/* FIXME: keep this dummy _get_type function around for now, so
|
|
* gobject-introspection doesn't fail in the GST_REMOVE_DEPRECATED and
|
|
* GST_DISABLE_LOADSAVE case */
|
|
GType gst_xml_get_type (void);
|
|
|
|
GType
|
|
gst_xml_get_type (void)
|
|
{
|
|
return g_pointer_type_register_static ("GstXML");
|
|
}
|
|
|
|
#endif
|