2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2004 Wim Taymans <wim@fluendo.com>
5 * gstelement.c: The base element, all elements derive from this
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
25 * @short_description: Abstract base class for all pipeline elements
26 * @see_also: #GstElementFactory, #GstPad
28 * GstElement is the abstract base class needed to construct an element that
29 * can be used in a GStreamer pipeline. Please refer to the plugin writers
30 * guide for more information on creating #GstElement subclasses.
32 * The name of a #GstElement can be get with gst_element_get_name() and set with
33 * gst_element_set_name(). For speed, GST_ELEMENT_NAME() can be used in the
34 * core when using the appropriate locking. Do not use this in plug-ins or
35 * applications in order to retain ABI compatibility.
37 * All elements have pads (of the type #GstPad). These pads link to pads on
38 * other elements. #GstBuffer flow between these linked pads.
39 * A #GstElement has a #GList of #GstPad structures for all their input (or sink)
40 * and output (or source) pads.
41 * Core and plug-in writers can add and remove pads with gst_element_add_pad()
42 * and gst_element_remove_pad().
44 * A pad of an element can be retrieved by name with gst_element_get_pad().
45 * An iterator of all pads can be retrieved with gst_element_iterate_pads().
47 * Elements can be linked through their pads.
48 * If the link is straightforward, use the gst_element_link()
49 * convenience function to link two elements, or gst_element_link_many()
50 * for more elements in a row.
51 * Use gst_element_link_filtered() to link two elements constrained by
52 * a specified set of #GstCaps.
53 * For finer control, use gst_element_link_pads() and
54 * gst_element_link_pads_filtered() to specify the pads to link on
55 * each element by name.
57 * Each element has a state (see #GstState). You can get and set the state
58 * of an element with gst_element_get_state() and gst_element_set_state().
59 * To get a string representation of a #GstState, use
60 * gst_element_state_get_name().
62 * You can get and set a #GstClock on an element using gst_element_get_clock()
63 * and gst_element_set_clock().
64 * Some elements can provide a clock for the pipeline if
65 * gst_element_provides_clock() returns %TRUE. With the
66 * gst_element_provide_clock() method one can retrieve the clock provided by
68 * Not all elements require a clock to operate correctly. If
69 * gst_element_requires_clock() returns %TRUE, a clock should be set on the
70 * element with gst_element_set_clock().
72 * Note that clock slection and distribution is normally handled by the
73 * toplevel #GstPipeline so the clock functions are only to be used in very
74 * specific situations.
76 * Last reviewed on 2006-03-12 (0.10.5)
79 #include "gst_private.h"
82 #include <gobject/gvaluecollector.h>
84 #include "gstelement.h"
86 #include "gstmarshal.h"
91 #include "gst-i18n-lib.h"
93 /* Element signals and args */
109 extern void __gst_element_details_clear (GstElementDetails * dp);
110 extern void __gst_element_details_copy (GstElementDetails * dest,
111 const GstElementDetails * src);
113 static void gst_element_class_init (GstElementClass * klass);
114 static void gst_element_init (GstElement * element);
115 static void gst_element_base_class_init (gpointer g_class);
116 static void gst_element_base_class_finalize (gpointer g_class);
118 static void gst_element_dispose (GObject * object);
119 static void gst_element_finalize (GObject * object);
121 static GstStateChangeReturn gst_element_change_state (GstElement * element,
122 GstStateChange transition);
123 static GstStateChangeReturn gst_element_change_state_func (GstElement * element,
124 GstStateChange transition);
125 static GstStateChangeReturn gst_element_get_state_func (GstElement * element,
126 GstState * state, GstState * pending, GstClockTime timeout);
127 static GstStateChangeReturn gst_element_set_state_func (GstElement * element,
129 static void gst_element_set_bus_func (GstElement * element, GstBus * bus);
131 static gboolean gst_element_default_send_event (GstElement * element,
133 static gboolean gst_element_default_query (GstElement * element,
136 #ifndef GST_DISABLE_LOADSAVE
137 static xmlNodePtr gst_element_save_thyself (GstObject * object,
139 static void gst_element_restore_thyself (GstObject * parent, xmlNodePtr self);
142 static GstObjectClass *parent_class = NULL;
143 static guint gst_element_signals[LAST_SIGNAL] = { 0 };
146 gst_element_get_type (void)
148 static GType gst_element_type = 0;
150 if (G_UNLIKELY (gst_element_type == 0)) {
151 static const GTypeInfo element_info = {
152 sizeof (GstElementClass),
153 gst_element_base_class_init,
154 gst_element_base_class_finalize,
155 (GClassInitFunc) gst_element_class_init,
160 (GInstanceInitFunc) gst_element_init,
164 gst_element_type = g_type_register_static (GST_TYPE_OBJECT, "GstElement",
165 &element_info, G_TYPE_FLAG_ABSTRACT);
167 return gst_element_type;
171 gst_element_class_init (GstElementClass * klass)
173 GObjectClass *gobject_class;
174 GstObjectClass *gstobject_class;
176 gobject_class = (GObjectClass *) klass;
177 gstobject_class = (GstObjectClass *) klass;
179 parent_class = g_type_class_peek_parent (klass);
182 * GstElement::pad-added:
183 * @gstelement: the object which received the signal
184 * @new_pad: the pad that has been added
186 * a new #GstPad has been added to the element.
188 gst_element_signals[PAD_ADDED] =
189 g_signal_new ("pad-added", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
190 G_STRUCT_OFFSET (GstElementClass, pad_added), NULL, NULL,
191 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
193 * GstElement::pad-removed:
194 * @gstelement: the object which received the signal
195 * @old_pad: the pad that has been removed
197 * a #GstPad has been removed from the element
199 gst_element_signals[PAD_REMOVED] =
200 g_signal_new ("pad-removed", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
201 G_STRUCT_OFFSET (GstElementClass, pad_removed), NULL, NULL,
202 gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
204 * GstElement::no-more-pads:
205 * @gstelement: the object which received the signal
207 * This signals that the element will not generate more dynamic pads.
209 gst_element_signals[NO_MORE_PADS] =
210 g_signal_new ("no-more-pads", G_TYPE_FROM_CLASS (klass),
211 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, no_more_pads), NULL,
212 NULL, gst_marshal_VOID__VOID, G_TYPE_NONE, 0);
214 gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_element_dispose);
215 gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_element_finalize);
217 #ifndef GST_DISABLE_LOADSAVE
218 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_element_save_thyself);
219 gstobject_class->restore_thyself =
220 GST_DEBUG_FUNCPTR (gst_element_restore_thyself);
223 klass->change_state = GST_DEBUG_FUNCPTR (gst_element_change_state_func);
224 klass->set_state = GST_DEBUG_FUNCPTR (gst_element_set_state_func);
225 klass->get_state = GST_DEBUG_FUNCPTR (gst_element_get_state_func);
226 klass->set_bus = GST_DEBUG_FUNCPTR (gst_element_set_bus_func);
227 klass->query = GST_DEBUG_FUNCPTR (gst_element_default_query);
228 klass->send_event = GST_DEBUG_FUNCPTR (gst_element_default_send_event);
229 klass->numpadtemplates = 0;
231 klass->elementfactory = NULL;
235 gst_element_base_class_init (gpointer g_class)
237 GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
239 memset (&element_class->details, 0, sizeof (GstElementDetails));
240 element_class->padtemplates = NULL;
244 gst_element_base_class_finalize (gpointer g_class)
246 GstElementClass *klass = GST_ELEMENT_CLASS (g_class);
248 g_list_foreach (klass->padtemplates, (GFunc) gst_object_unref, NULL);
249 g_list_free (klass->padtemplates);
250 __gst_element_details_clear (&klass->details);
254 gst_element_init (GstElement * element)
256 GST_STATE (element) = GST_STATE_NULL;
257 GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING;
258 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
259 GST_STATE_RETURN (element) = GST_STATE_CHANGE_SUCCESS;
261 element->state_lock = g_new0 (GStaticRecMutex, 1);
262 g_static_rec_mutex_init (element->state_lock);
263 element->state_cond = g_cond_new ();
267 * gst_element_default_error:
268 * @object: a #GObject that signalled the error.
269 * @orig: the #GstObject that initiated the error.
270 * @error: the GError.
271 * @debug: an additional debug information string, or %NULL.
273 * A default error signal callback to attach to an element.
274 * The user data passed to the g_signal_connect is ignored.
276 * The default handler will simply print the error string using g_print.
281 gst_element_default_error (GObject * object, GstObject * source, GError * error,
284 gchar *name = gst_object_get_path_string (source);
286 g_print (_("ERROR: from element %s: %s\n"), name, error->message);
288 g_print (_("Additional debug info:\n%s\n"), debug);
294 * gst_element_release_request_pad:
295 * @element: a #GstElement to release the request pad of.
296 * @pad: the #GstPad to release.
298 * Makes the element free the previously requested pad as obtained
299 * with gst_element_get_request_pad().
304 gst_element_release_request_pad (GstElement * element, GstPad * pad)
306 GstElementClass *oclass;
308 g_return_if_fail (GST_IS_ELEMENT (element));
309 g_return_if_fail (GST_IS_PAD (pad));
311 oclass = GST_ELEMENT_GET_CLASS (element);
313 /* if the element implements a custom release function we call that, else we
314 * simply remove the pad from the element */
315 if (oclass->release_pad)
316 (oclass->release_pad) (element, pad);
318 gst_element_remove_pad (element, pad);
322 * gst_element_requires_clock:
323 * @element: a #GstElement to query
325 * Query if the element requires a clock.
327 * Returns: %TRUE if the element requires a clock
332 gst_element_requires_clock (GstElement * element)
336 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
338 result = (GST_ELEMENT_GET_CLASS (element)->set_clock != NULL);
344 * gst_element_provides_clock:
345 * @element: a #GstElement to query
347 * Query if the element provides a clock. A #GstClock provided by an
348 * element can be used as the global #GstClock for the pipeline.
349 * An element that can provide a clock is only required to do so in the PAUSED
350 * state, this means when it is fully negotiated and has allocated the resources
351 * to operate the clock.
353 * Returns: %TRUE if the element provides a clock
358 gst_element_provides_clock (GstElement * element)
362 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
364 result = (GST_ELEMENT_GET_CLASS (element)->provide_clock != NULL);
370 * gst_element_provide_clock:
371 * @element: a #GstElement to query
373 * Get the clock provided by the given element.
374 * <note>An element is only required to provide a clock in the PAUSED
375 * state. Some elements can provide a clock in other states.</note>
377 * Returns: the GstClock provided by the element or %NULL
378 * if no clock could be provided. Unref after usage.
383 gst_element_provide_clock (GstElement * element)
385 GstClock *result = NULL;
386 GstElementClass *oclass;
388 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
390 oclass = GST_ELEMENT_GET_CLASS (element);
392 if (oclass->provide_clock)
393 result = oclass->provide_clock (element);
399 * gst_element_set_clock:
400 * @element: a #GstElement to set the clock for.
401 * @clock: the #GstClock to set for the element.
403 * Sets the clock for the element. This function increases the
404 * refcount on the clock. Any previously set clock on the object
407 * Returns: %TRUE if the element accepted the clock. An element can refuse a
408 * clock when it, for example, is not able to slave its internal clock to the
409 * @clock or when it requires a specific clock to operate.
414 gst_element_set_clock (GstElement * element, GstClock * clock)
416 GstElementClass *oclass;
420 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
422 oclass = GST_ELEMENT_GET_CLASS (element);
424 GST_DEBUG_OBJECT (element, "setting clock %p", clock);
426 if (oclass->set_clock)
427 res = oclass->set_clock (element, clock);
430 /* only update the clock pointer if the element accepted the clock */
431 GST_OBJECT_LOCK (element);
432 clock_p = &element->clock;
433 gst_object_replace ((GstObject **) clock_p, (GstObject *) clock);
434 GST_OBJECT_UNLOCK (element);
440 * gst_element_get_clock:
441 * @element: a #GstElement to get the clock of.
443 * Gets the currently configured clock of the element. This is the clock as was
444 * last set with gst_element_set_clock().
446 * Returns: the #GstClock of the element. unref after usage.
451 gst_element_get_clock (GstElement * element)
455 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
457 GST_OBJECT_LOCK (element);
458 if ((result = element->clock))
459 gst_object_ref (result);
460 GST_OBJECT_UNLOCK (element);
466 * gst_element_set_base_time:
467 * @element: a #GstElement.
468 * @time: the base time to set.
470 * Set the base time of an element. See gst_element_get_base_time().
475 gst_element_set_base_time (GstElement * element, GstClockTime time)
477 g_return_if_fail (GST_IS_ELEMENT (element));
479 GST_OBJECT_LOCK (element);
480 element->base_time = time;
481 GST_OBJECT_UNLOCK (element);
483 GST_DEBUG_OBJECT (element, "set base_time=%" GST_TIME_FORMAT,
484 GST_TIME_ARGS (time));
488 * gst_element_get_base_time:
489 * @element: a #GstElement.
491 * Returns the base time of the element. The base time is the
492 * absolute time of the clock when this element was last put to
493 * PLAYING. Subtracting the base time from the clock time gives
494 * the stream time of the element.
496 * Returns: the base time of the element.
501 gst_element_get_base_time (GstElement * element)
505 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_CLOCK_TIME_NONE);
507 GST_OBJECT_LOCK (element);
508 result = element->base_time;
509 GST_OBJECT_UNLOCK (element);
514 #ifndef GST_DISABLE_INDEX
516 * gst_element_is_indexable:
517 * @element: a #GstElement.
519 * Queries if the element can be indexed.
521 * Returns: TRUE if the element can be indexed.
526 gst_element_is_indexable (GstElement * element)
530 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
532 result = (GST_ELEMENT_GET_CLASS (element)->set_index != NULL);
538 * gst_element_set_index:
539 * @element: a #GstElement.
540 * @index: a #GstIndex.
542 * Set @index on the element. The refcount of the index
543 * will be increased, any previously set index is unreffed.
548 gst_element_set_index (GstElement * element, GstIndex * index)
550 GstElementClass *oclass;
552 g_return_if_fail (GST_IS_ELEMENT (element));
553 g_return_if_fail (GST_IS_INDEX (index));
555 oclass = GST_ELEMENT_GET_CLASS (element);
557 if (oclass->set_index)
558 oclass->set_index (element, index);
562 * gst_element_get_index:
563 * @element: a #GstElement.
565 * Gets the index from the element.
567 * Returns: a #GstIndex or %NULL when no index was set on the
568 * element. unref after usage.
573 gst_element_get_index (GstElement * element)
575 GstElementClass *oclass;
576 GstIndex *result = NULL;
578 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
580 oclass = GST_ELEMENT_GET_CLASS (element);
582 if (oclass->get_index)
583 result = oclass->get_index (element);
590 * gst_element_add_pad:
591 * @element: a #GstElement to add the pad to.
592 * @pad: the #GstPad to add to the element.
594 * Adds a pad (link point) to @element. @pad's parent will be set to @element;
595 * see gst_object_set_parent() for refcounting information.
597 * Pads are not automatically activated so elements should perform the needed
598 * steps to activate the pad in case this pad is added in the PAUSED or PLAYING
599 * state. See gst_pad_set_active() for more information about activating pads.
601 * The pad and the element should be unlocked when calling this function.
603 * This function will emit the #GstElement::pad-added signal on the element.
605 * Returns: %TRUE if the pad could be added. This function can fail when
606 * a pad with the same name already existed or the pad already had another
612 gst_element_add_pad (GstElement * element, GstPad * pad)
617 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
618 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
620 /* locking pad to look at the name */
621 GST_OBJECT_LOCK (pad);
622 pad_name = g_strdup (GST_PAD_NAME (pad));
623 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "adding pad '%s'",
624 GST_STR_NULL (pad_name));
625 flushing = GST_PAD_IS_FLUSHING (pad);
626 GST_OBJECT_UNLOCK (pad);
628 /* then check to see if there's already a pad by that name here */
629 GST_OBJECT_LOCK (element);
630 if (G_UNLIKELY (!gst_object_check_uniqueness (element->pads, pad_name)))
633 /* try to set the pad's parent */
634 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (pad),
635 GST_OBJECT_CAST (element))))
638 /* check for flushing pads */
639 if (flushing && (GST_STATE (element) > GST_STATE_READY ||
640 GST_STATE_NEXT (element) == GST_STATE_PAUSED)) {
641 g_warning ("adding flushing pad '%s' to running element '%s'",
642 GST_STR_NULL (pad_name), GST_ELEMENT_NAME (element));
644 GST_OBJECT_LOCK (pad);
645 GST_PAD_UNSET_FLUSHING (pad);
646 GST_OBJECT_UNLOCK (pad);
651 /* add it to the list */
652 switch (gst_pad_get_direction (pad)) {
654 element->srcpads = g_list_prepend (element->srcpads, pad);
655 element->numsrcpads++;
658 element->sinkpads = g_list_prepend (element->sinkpads, pad);
659 element->numsinkpads++;
664 element->pads = g_list_prepend (element->pads, pad);
666 element->pads_cookie++;
667 GST_OBJECT_UNLOCK (element);
669 /* emit the PAD_ADDED signal */
670 g_signal_emit (element, gst_element_signals[PAD_ADDED], 0, pad);
677 g_critical ("Padname %s is not unique in element %s, not adding",
678 pad_name, GST_ELEMENT_NAME (element));
679 GST_OBJECT_UNLOCK (element);
686 ("Pad %s already has parent when trying to add to element %s",
687 pad_name, GST_ELEMENT_NAME (element));
688 GST_OBJECT_UNLOCK (element);
694 GST_OBJECT_LOCK (pad);
696 ("Trying to add pad %s to element %s, but it has no direction",
697 GST_OBJECT_NAME (pad), GST_ELEMENT_NAME (element));
698 GST_OBJECT_UNLOCK (pad);
699 GST_OBJECT_UNLOCK (element);
705 * gst_element_remove_pad:
706 * @element: a #GstElement to remove pad from.
707 * @pad: the #GstPad to remove from the element.
709 * Removes @pad from @element. @pad will be destroyed if it has not been
710 * referenced elsewhere using gst_object_unparent().
712 * This function is used by plugin developers and should not be used
713 * by applications. Pads that were dynamically requested from elements
714 * with gst_element_get_request_pad() should be released with the
715 * gst_element_release_request_pad() function instead.
717 * Pads are not automatically deactivated so elements should perform the needed
718 * steps to deactivate the pad in case this pad is removed in the PAUSED or
719 * PLAYING state. See gst_pad_set_active() for more information about
722 * The pad and the element should be unlocked when calling this function.
724 * This function will emit the #GstElement::pad-removed signal on the element.
726 * Returns: %TRUE if the pad could be removed. Can return %FALSE if the
727 * pad does not belong to the provided element.
732 gst_element_remove_pad (GstElement * element, GstPad * pad)
736 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
737 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
739 /* locking pad to look at the name and parent */
740 GST_OBJECT_LOCK (pad);
741 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "removing pad '%s'",
742 GST_STR_NULL (GST_PAD_NAME (pad)));
744 if (G_UNLIKELY (GST_PAD_PARENT (pad) != element))
746 GST_OBJECT_UNLOCK (pad);
749 if ((peer = gst_pad_get_peer (pad))) {
750 /* window for MT unsafeness, someone else could unlink here
751 * and then we call unlink with wrong pads. The unlink
752 * function would catch this and safely return failed. */
753 if (GST_PAD_IS_SRC (pad))
754 gst_pad_unlink (pad, peer);
756 gst_pad_unlink (peer, pad);
758 gst_object_unref (peer);
761 GST_OBJECT_LOCK (element);
762 /* remove it from the list */
763 switch (gst_pad_get_direction (pad)) {
765 element->srcpads = g_list_remove (element->srcpads, pad);
766 element->numsrcpads--;
769 element->sinkpads = g_list_remove (element->sinkpads, pad);
770 element->numsinkpads--;
773 g_critical ("Removing pad without direction???");
776 element->pads = g_list_remove (element->pads, pad);
778 element->pads_cookie++;
779 GST_OBJECT_UNLOCK (element);
781 /* emit the PAD_REMOVED signal before unparenting and losing the last ref. */
782 g_signal_emit (element, gst_element_signals[PAD_REMOVED], 0, pad);
784 gst_object_unparent (GST_OBJECT_CAST (pad));
791 /* FIXME, locking order? */
792 GST_OBJECT_LOCK (element);
793 g_critical ("Padname %s:%s does not belong to element %s when removing",
794 GST_DEBUG_PAD_NAME (pad), GST_ELEMENT_NAME (element));
795 GST_OBJECT_UNLOCK (element);
796 GST_OBJECT_UNLOCK (pad);
802 * gst_element_no_more_pads:
803 * @element: a #GstElement
805 * Use this function to signal that the element does not expect any more pads
806 * to show up in the current pipeline. This function should be called whenever
807 * pads have been added by the element itself. Elements with #GST_PAD_SOMETIMES
808 * pad templates use this in combination with autopluggers to figure out that
809 * the element is done initializing its pads.
811 * This function emits the #GstElement::no-more-pads signal.
816 gst_element_no_more_pads (GstElement * element)
818 g_return_if_fail (GST_IS_ELEMENT (element));
820 g_signal_emit (element, gst_element_signals[NO_MORE_PADS], 0);
824 pad_compare_name (GstPad * pad1, const gchar * name)
828 GST_OBJECT_LOCK (pad1);
829 result = strcmp (GST_PAD_NAME (pad1), name);
830 GST_OBJECT_UNLOCK (pad1);
836 * gst_element_get_static_pad:
837 * @element: a #GstElement to find a static pad of.
838 * @name: the name of the static #GstPad to retrieve.
840 * Retrieves a pad from @element by name. This version only retrieves
841 * already-existing (i.e. 'static') pads.
843 * Returns: the requested #GstPad if found, otherwise %NULL. unref after
849 gst_element_get_static_pad (GstElement * element, const gchar * name)
852 GstPad *result = NULL;
854 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
855 g_return_val_if_fail (name != NULL, NULL);
857 GST_OBJECT_LOCK (element);
859 g_list_find_custom (element->pads, name, (GCompareFunc) pad_compare_name);
861 result = GST_PAD_CAST (find->data);
862 gst_object_ref (result);
865 if (result == NULL) {
866 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "no such pad '%s' in element \"%s\"",
867 name, GST_ELEMENT_NAME (element));
869 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "found pad %s:%s",
870 GST_ELEMENT_NAME (element), name);
872 GST_OBJECT_UNLOCK (element);
878 gst_element_request_pad (GstElement * element, GstPadTemplate * templ,
881 GstPad *newpad = NULL;
882 GstElementClass *oclass;
884 oclass = GST_ELEMENT_GET_CLASS (element);
886 if (oclass->request_new_pad)
887 newpad = (oclass->request_new_pad) (element, templ, name);
890 gst_object_ref (newpad);
896 * gst_element_get_request_pad:
897 * @element: a #GstElement to find a request pad of.
898 * @name: the name of the request #GstPad to retrieve.
900 * Retrieves a pad from the element by name. This version only retrieves
901 * request pads. The pad should be released with
902 * gst_element_release_request_pad().
904 * Returns: requested #GstPad if found, otherwise %NULL. Release after usage.
907 gst_element_get_request_pad (GstElement * element, const gchar * name)
909 GstPadTemplate *templ = NULL;
911 const gchar *req_name = NULL;
912 gboolean templ_found = FALSE;
916 gchar *str, *endptr = NULL;
917 GstElementClass *class;
919 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
920 g_return_val_if_fail (name != NULL, NULL);
922 class = GST_ELEMENT_GET_CLASS (element);
924 if (strstr (name, "%")) {
925 templ = gst_element_class_get_pad_template (class, name);
930 list = gst_element_class_get_pad_template_list (class);
931 while (!templ_found && list) {
932 templ = (GstPadTemplate *) list->data;
933 if (templ->presence == GST_PAD_REQUEST) {
934 /* Because of sanity checks in gst_pad_template_new(), we know that %s
935 and %d, occurring at the end of the name_template, are the only
937 GST_CAT_DEBUG (GST_CAT_PADS, "comparing %s to %s", name,
938 templ->name_template);
939 if ((str = strchr (templ->name_template, '%'))
940 && strncmp (templ->name_template, name,
941 str - templ->name_template) == 0
942 && strlen (name) > str - templ->name_template) {
943 data = name + (str - templ->name_template);
944 if (*(str + 1) == 'd') {
946 n = (gint) strtol (data, &endptr, 10);
947 if (endptr && *endptr == '\0') {
967 pad = gst_element_request_pad (element, templ, req_name);
973 * gst_element_get_pad:
974 * @element: a #GstElement.
975 * @name: the name of the pad to retrieve.
977 * Retrieves a pad from @element by name. Tries gst_element_get_static_pad()
978 * first, then gst_element_get_request_pad().
980 * <note>Usage of this function is not recommended as it is unclear if the reference
981 * to the result pad should be released with gst_object_unref() in case of a static pad
982 * or gst_element_release_request_pad() in case of a request pad.</note>
984 * Returns: the #GstPad if found, otherwise %NULL. Unref or Release after usage,
985 * depending on the type of the pad.
988 gst_element_get_pad (GstElement * element, const gchar * name)
992 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
993 g_return_val_if_fail (name != NULL, NULL);
995 pad = gst_element_get_static_pad (element, name);
997 pad = gst_element_get_request_pad (element, name);
1002 static GstIteratorItem
1003 iterate_pad (GstIterator * it, GstPad * pad)
1005 gst_object_ref (pad);
1006 return GST_ITERATOR_ITEM_PASS;
1009 static GstIterator *
1010 gst_element_iterate_pad_list (GstElement * element, GList ** padlist)
1012 GstIterator *result;
1014 GST_OBJECT_LOCK (element);
1015 gst_object_ref (element);
1016 result = gst_iterator_new_list (GST_TYPE_PAD,
1017 GST_OBJECT_GET_LOCK (element),
1018 &element->pads_cookie,
1021 (GstIteratorItemFunction) iterate_pad,
1022 (GstIteratorDisposeFunction) gst_object_unref);
1023 GST_OBJECT_UNLOCK (element);
1029 * gst_element_iterate_pads:
1030 * @element: a #GstElement to iterate pads of.
1032 * Retrieves an iterattor of @element's pads. The iterator should
1033 * be freed after usage.
1035 * Returns: the #GstIterator of #GstPad. Unref each pad after use.
1040 gst_element_iterate_pads (GstElement * element)
1042 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1044 return gst_element_iterate_pad_list (element, &element->pads);
1048 * gst_element_iterate_src_pads:
1049 * @element: a #GstElement.
1051 * Retrieves an iterator of @element's source pads.
1053 * Returns: the #GstIterator of #GstPad. Unref each pad after use.
1058 gst_element_iterate_src_pads (GstElement * element)
1060 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1062 return gst_element_iterate_pad_list (element, &element->srcpads);
1066 * gst_element_iterate_sink_pads:
1067 * @element: a #GstElement.
1069 * Retrieves an iterator of @element's sink pads.
1071 * Returns: the #GstIterator of #GstPad. Unref each pad after use.
1076 gst_element_iterate_sink_pads (GstElement * element)
1078 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1080 return gst_element_iterate_pad_list (element, &element->sinkpads);
1084 * gst_element_class_add_pad_template:
1085 * @klass: the #GstElementClass to add the pad template to.
1086 * @templ: a #GstPadTemplate to add to the element class.
1088 * Adds a padtemplate to an element class. This is mainly used in the _base_init
1089 * functions of classes.
1092 gst_element_class_add_pad_template (GstElementClass * klass,
1093 GstPadTemplate * templ)
1095 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1096 g_return_if_fail (GST_IS_PAD_TEMPLATE (templ));
1098 /* avoid registering pad templates with the same name */
1099 g_return_if_fail (gst_element_class_get_pad_template (klass,
1100 templ->name_template) == NULL);
1102 klass->padtemplates = g_list_append (klass->padtemplates,
1103 gst_object_ref (templ));
1104 klass->numpadtemplates++;
1108 * gst_element_class_set_details:
1109 * @klass: class to set details for
1110 * @details: details to set
1112 * Sets the detailed information for a #GstElementClass.
1113 * <note>This function is for use in _base_init functions only.</note>
1115 * The @details are copied.
1118 gst_element_class_set_details (GstElementClass * klass,
1119 const GstElementDetails * details)
1121 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1122 g_return_if_fail (GST_IS_ELEMENT_DETAILS (details));
1124 __gst_element_details_copy (&klass->details, details);
1128 * gst_element_class_get_pad_template_list:
1129 * @element_class: a #GstElementClass to get pad templates of.
1131 * Retrieves a list of the pad templates associated with @element_class. The
1132 * list must not be modified by the calling code.
1133 * <note>If you use this function in the #GInstanceInitFunc of an object class
1134 * that has subclasses, make sure to pass the g_class parameter of the
1135 * #GInstanceInitFunc here.</note>
1137 * Returns: the #GList of padtemplates.
1140 gst_element_class_get_pad_template_list (GstElementClass * element_class)
1142 g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL);
1144 return element_class->padtemplates;
1148 * gst_element_class_get_pad_template:
1149 * @element_class: a #GstElementClass to get the pad template of.
1150 * @name: the name of the #GstPadTemplate to get.
1152 * Retrieves a padtemplate from @element_class with the given name.
1153 * <note>If you use this function in the #GInstanceInitFunc of an object class
1154 * that has subclasses, make sure to pass the g_class parameter of the
1155 * #GInstanceInitFunc here.</note>
1157 * Returns: the #GstPadTemplate with the given name, or %NULL if none was found.
1158 * No unreferencing is necessary.
1161 gst_element_class_get_pad_template (GstElementClass * element_class,
1166 g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL);
1167 g_return_val_if_fail (name != NULL, NULL);
1169 padlist = gst_element_class_get_pad_template_list (element_class);
1172 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
1174 if (strcmp (padtempl->name_template, name) == 0)
1177 padlist = g_list_next (padlist);
1183 /* get a random pad on element of the given direction.
1184 * The pad is random in a sense that it is the first pad that is (optionaly) linked.
1187 gst_element_get_random_pad (GstElement * element, gboolean need_linked,
1188 GstPadDirection dir)
1190 GstPad *result = NULL;
1193 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "getting a random pad");
1197 GST_OBJECT_LOCK (element);
1198 pads = element->srcpads;
1201 GST_OBJECT_LOCK (element);
1202 pads = element->sinkpads;
1205 goto wrong_direction;
1207 for (; pads; pads = g_list_next (pads)) {
1208 GstPad *pad = GST_PAD_CAST (pads->data);
1210 GST_OBJECT_LOCK (pad);
1211 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "checking pad %s:%s",
1212 GST_DEBUG_PAD_NAME (pad));
1214 if (need_linked && !GST_PAD_IS_LINKED (pad)) {
1215 /* if we require a linked pad, and it is not linked, continue the
1217 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is not linked",
1218 GST_DEBUG_PAD_NAME (pad));
1219 GST_OBJECT_UNLOCK (pad);
1222 /* found a pad, stop search */
1223 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "found pad %s:%s",
1224 GST_DEBUG_PAD_NAME (pad));
1225 GST_OBJECT_UNLOCK (pad);
1231 gst_object_ref (result);
1233 GST_OBJECT_UNLOCK (element);
1237 /* ERROR handling */
1240 g_warning ("unknown pad direction %d", dir);
1246 gst_element_default_send_event (GstElement * element, GstEvent * event)
1248 gboolean result = FALSE;
1251 pad = GST_EVENT_IS_DOWNSTREAM (event) ?
1252 gst_element_get_random_pad (element, TRUE, GST_PAD_SRC) :
1253 gst_element_get_random_pad (element, TRUE, GST_PAD_SINK);
1256 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1257 "pushing %s event to random %s pad %s:%s",
1258 GST_EVENT_TYPE_NAME (event),
1259 (GST_PAD_DIRECTION (pad) == GST_PAD_SRC ? "src" : "sink"),
1260 GST_DEBUG_PAD_NAME (pad));
1262 result = gst_pad_push_event (pad, event);
1263 gst_object_unref (pad);
1265 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "can't send %s event on element %s",
1266 GST_EVENT_TYPE_NAME (event), GST_ELEMENT_NAME (element));
1272 * gst_element_send_event:
1273 * @element: a #GstElement to send the event to.
1274 * @event: the #GstEvent to send to the element.
1276 * Sends an event to an element. If the element doesn't implement an
1277 * event handler, the event will be pushed on a random linked sink pad for
1278 * upstream events or a random linked source pad for downstream events.
1280 * This function takes owership of the provided event so you should
1281 * gst_event_ref() it if you want to reuse the event after this call.
1283 * Returns: %TRUE if the event was handled.
1288 gst_element_send_event (GstElement * element, GstEvent * event)
1290 GstElementClass *oclass;
1291 gboolean result = FALSE;
1293 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1294 g_return_val_if_fail (event != NULL, FALSE);
1296 oclass = GST_ELEMENT_GET_CLASS (element);
1298 if (oclass->send_event) {
1299 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "send %s event on element %s",
1300 GST_EVENT_TYPE_NAME (event), GST_ELEMENT_NAME (element));
1301 result = oclass->send_event (element, event);
1303 result = gst_element_default_send_event (element, event);
1310 * @element: a #GstElement to send the event to.
1311 * @rate: The new playback rate
1312 * @format: The format of the seek values
1313 * @flags: The optional seek flags.
1314 * @cur_type: The type and flags for the new current position
1315 * @cur: The value of the new current position
1316 * @stop_type: The type and flags for the new stop position
1317 * @stop: The value of the new stop position
1319 * Sends a seek event to an element. See gst_event_new_seek() for the details of
1320 * the parameters. The seek event is sent to the element using
1321 * gst_element_send_event().
1323 * Returns: %TRUE if the event was handled.
1328 gst_element_seek (GstElement * element, gdouble rate, GstFormat format,
1329 GstSeekFlags flags, GstSeekType cur_type, gint64 cur,
1330 GstSeekType stop_type, gint64 stop)
1335 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1338 gst_event_new_seek (rate, format, flags, cur_type, cur, stop_type, stop);
1339 result = gst_element_send_event (element, event);
1345 * gst_element_get_query_types:
1346 * @element: a #GstElement to query
1348 * Get an array of query types from the element.
1349 * If the element doesn't implement a query types function,
1350 * the query will be forwarded to the peer of a random linked sink pad.
1352 * Returns: An array of #GstQueryType elements that should not
1353 * be freed or modified.
1357 const GstQueryType *
1358 gst_element_get_query_types (GstElement * element)
1360 GstElementClass *oclass;
1361 const GstQueryType *result = NULL;
1363 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1365 oclass = GST_ELEMENT_GET_CLASS (element);
1367 if (oclass->get_query_types) {
1368 result = oclass->get_query_types (element);
1370 GstPad *pad = gst_element_get_random_pad (element, TRUE, GST_PAD_SINK);
1373 GstPad *peer = gst_pad_get_peer (pad);
1376 result = gst_pad_get_query_types (peer);
1378 gst_object_unref (peer);
1380 gst_object_unref (pad);
1387 gst_element_default_query (GstElement * element, GstQuery * query)
1389 gboolean result = FALSE;
1392 pad = gst_element_get_random_pad (element, FALSE, GST_PAD_SRC);
1394 result = gst_pad_query (pad, query);
1396 gst_object_unref (pad);
1398 pad = gst_element_get_random_pad (element, TRUE, GST_PAD_SINK);
1400 GstPad *peer = gst_pad_get_peer (pad);
1403 result = gst_pad_query (peer, query);
1405 gst_object_unref (peer);
1407 gst_object_unref (pad);
1414 * gst_element_query:
1415 * @element: a #GstElement to perform the query on.
1416 * @query: the #GstQuery.
1418 * Performs a query on the given element.
1420 * For elements that don't implement a query handler, this function
1421 * forwards the query to a random srcpad or to the peer of a
1422 * random linked sinkpad of this element.
1424 * Returns: TRUE if the query could be performed.
1429 gst_element_query (GstElement * element, GstQuery * query)
1431 GstElementClass *oclass;
1432 gboolean result = FALSE;
1434 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1435 g_return_val_if_fail (query != NULL, FALSE);
1437 oclass = GST_ELEMENT_GET_CLASS (element);
1439 if (oclass->query) {
1440 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "send query on element %s",
1441 GST_ELEMENT_NAME (element));
1442 result = oclass->query (element, query);
1444 result = gst_element_default_query (element, query);
1450 * gst_element_post_message:
1451 * @element: a #GstElement posting the message
1452 * @message: a #GstMessage to post
1454 * Post a message on the element's #GstBus. This function takes ownership of the
1455 * message; if you want to access the message after this call, you should add an
1456 * additional reference before calling.
1458 * Returns: %TRUE if the message was successfully posted. The function returns
1459 * %FALSE if the element did not have a bus.
1464 gst_element_post_message (GstElement * element, GstMessage * message)
1467 gboolean result = FALSE;
1469 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1470 g_return_val_if_fail (message != NULL, FALSE);
1472 GST_OBJECT_LOCK (element);
1475 if (G_UNLIKELY (bus == NULL))
1478 gst_object_ref (bus);
1479 GST_OBJECT_UNLOCK (element);
1481 /* we release the element lock when posting the message so that any
1482 * (synchronous) message handlers can operate on the element */
1483 result = gst_bus_post (bus, message);
1484 gst_object_unref (bus);
1491 GST_DEBUG_OBJECT (element, "not posting message %p: no bus", message);
1492 GST_OBJECT_UNLOCK (element);
1493 gst_message_unref (message);
1499 * _gst_element_error_printf:
1500 * @format: the printf-like format to use, or %NULL
1502 * This function is only used internally by the gst_element_error() macro.
1504 * Returns: a newly allocated string, or %NULL if the format was %NULL or ""
1509 _gst_element_error_printf (const gchar * format, ...)
1519 va_start (args, format);
1520 buffer = g_strdup_vprintf (format, args);
1526 * gst_element_message_full:
1527 * @element: a #GstElement to send message from
1528 * @type: the #GstMessageType
1529 * @domain: the GStreamer GError domain this message belongs to
1530 * @code: the GError code belonging to the domain
1531 * @text: an allocated text string to be used as a replacement for the
1532 * default message connected to code, or %NULL
1533 * @debug: an allocated debug message to be used as a replacement for the
1534 * default debugging information, or %NULL
1535 * @file: the source code file where the error was generated
1536 * @function: the source code function where the error was generated
1537 * @line: the source code line where the error was generated
1539 * Post an error or warning message on the bus from inside an element.
1543 void gst_element_message_full
1544 (GstElement * element, GstMessageType type,
1545 GQuark domain, gint code, gchar * text,
1546 gchar * debug, const gchar * file, const gchar * function, gint line)
1548 GError *gerror = NULL;
1552 gboolean has_debug = TRUE;
1553 GstMessage *message = NULL;
1556 GST_DEBUG_OBJECT (element, "start");
1557 g_return_if_fail (GST_IS_ELEMENT (element));
1558 g_return_if_fail ((type == GST_MESSAGE_ERROR) ||
1559 (type == GST_MESSAGE_WARNING) || (type == GST_MESSAGE_INFO));
1561 /* check if we send the given text or the default error text */
1562 if ((text == NULL) || (text[0] == 0)) {
1563 /* text could have come from g_strdup_printf (""); */
1565 sent_text = gst_error_get_message (domain, code);
1569 /* construct a sent_debug with extra information from source */
1570 if ((debug == NULL) || (debug[0] == 0)) {
1571 /* debug could have come from g_strdup_printf (""); */
1575 name = gst_object_get_path_string (GST_OBJECT_CAST (element));
1577 sent_debug = g_strdup_printf ("%s(%d): %s (): %s:\n%s",
1578 file, line, function, name, debug);
1580 sent_debug = g_strdup_printf ("%s(%d): %s (): %s",
1581 file, line, function, name);
1585 /* create gerror and post message */
1586 GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posting message: %s",
1588 gerror = g_error_new_literal (domain, code, sent_text);
1591 case GST_MESSAGE_ERROR:
1593 gst_message_new_error (GST_OBJECT_CAST (element), gerror, sent_debug);
1595 case GST_MESSAGE_WARNING:
1596 message = gst_message_new_warning (GST_OBJECT_CAST (element), gerror,
1599 case GST_MESSAGE_INFO:
1600 message = gst_message_new_info (GST_OBJECT_CAST (element), gerror,
1604 g_assert_not_reached ();
1607 gst_element_post_message (element, message);
1609 GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posted %s message: %s",
1610 (type == GST_MESSAGE_ERROR ? "error" : "warning"), sent_text);
1613 g_error_free (gerror);
1614 g_free (sent_debug);
1619 * gst_element_is_locked_state:
1620 * @element: a #GstElement.
1622 * Checks if the state of an element is locked.
1623 * If the state of an element is locked, state changes of the parent don't
1624 * affect the element.
1625 * This way you can leave currently unused elements inside bins. Just lock their
1626 * state before changing the state from #GST_STATE_NULL.
1630 * Returns: TRUE, if the element's state is locked.
1633 gst_element_is_locked_state (GstElement * element)
1637 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1639 GST_OBJECT_LOCK (element);
1640 result = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
1641 GST_OBJECT_UNLOCK (element);
1647 * gst_element_set_locked_state:
1648 * @element: a #GstElement
1649 * @locked_state: TRUE to lock the element's state
1651 * Locks the state of an element, so state changes of the parent don't affect
1652 * this element anymore.
1656 * Returns: TRUE if the state was changed, FALSE if bad parameters were given
1657 * or the elements state-locking needed no change.
1660 gst_element_set_locked_state (GstElement * element, gboolean locked_state)
1664 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1666 GST_OBJECT_LOCK (element);
1667 old = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
1669 if (G_UNLIKELY (old == locked_state))
1673 GST_CAT_DEBUG (GST_CAT_STATES, "locking state of element %s",
1674 GST_ELEMENT_NAME (element));
1675 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_LOCKED_STATE);
1677 GST_CAT_DEBUG (GST_CAT_STATES, "unlocking state of element %s",
1678 GST_ELEMENT_NAME (element));
1679 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_LOCKED_STATE);
1681 GST_OBJECT_UNLOCK (element);
1687 GST_CAT_DEBUG (GST_CAT_STATES, "elements %s was in locked state %d",
1688 GST_ELEMENT_NAME (element), old);
1689 GST_OBJECT_UNLOCK (element);
1696 * gst_element_sync_state_with_parent:
1697 * @element: a #GstElement.
1699 * Tries to change the state of the element to the same as its parent.
1700 * If this function returns FALSE, the state of element is undefined.
1702 * Returns: TRUE, if the element's state could be synced to the parent's state.
1707 gst_element_sync_state_with_parent (GstElement * element)
1711 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1713 if ((parent = GST_ELEMENT_CAST (gst_element_get_parent (element)))) {
1714 GstState parent_current, parent_pending;
1715 GstStateChangeReturn ret;
1717 GST_OBJECT_LOCK (parent);
1718 parent_current = GST_STATE (parent);
1719 parent_pending = GST_STATE_PENDING (parent);
1720 GST_OBJECT_UNLOCK (parent);
1722 GST_CAT_DEBUG (GST_CAT_STATES,
1723 "syncing state of element %s (%s) to %s (%s, %s)",
1724 GST_ELEMENT_NAME (element),
1725 gst_element_state_get_name (GST_STATE (element)),
1726 GST_ELEMENT_NAME (parent), gst_element_state_get_name (parent_current),
1727 gst_element_state_get_name (parent_pending));
1729 ret = gst_element_set_state (element, parent_current);
1730 if (ret == GST_STATE_CHANGE_FAILURE)
1733 gst_object_unref (parent);
1747 static GstStateChangeReturn
1748 gst_element_get_state_func (GstElement * element,
1749 GstState * state, GstState * pending, GstClockTime timeout)
1751 GstStateChangeReturn ret = GST_STATE_CHANGE_FAILURE;
1752 GstState old_pending;
1754 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "getting state, timeout %"
1755 GST_TIME_FORMAT, GST_TIME_ARGS (timeout));
1757 GST_OBJECT_LOCK (element);
1758 ret = GST_STATE_RETURN (element);
1759 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "RETURN is %s",
1760 gst_element_state_change_return_get_name (ret));
1762 /* we got an error, report immediatly */
1763 if (ret == GST_STATE_CHANGE_FAILURE)
1766 /* we got no_preroll, report immediatly */
1767 if (ret == GST_STATE_CHANGE_NO_PREROLL)
1770 /* no need to wait async if we are not async */
1771 if (ret != GST_STATE_CHANGE_ASYNC)
1774 old_pending = GST_STATE_PENDING (element);
1775 if (old_pending != GST_STATE_VOID_PENDING) {
1776 GTimeVal *timeval, abstimeout;
1779 if (timeout != GST_CLOCK_TIME_NONE) {
1780 glong add = timeout / 1000;
1785 /* make timeout absolute */
1786 g_get_current_time (&abstimeout);
1787 g_time_val_add (&abstimeout, add);
1788 timeval = &abstimeout;
1792 /* get cookie to dected state change during waiting */
1793 cookie = element->state_cookie;
1795 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
1796 "waiting for element to commit state");
1798 /* we have a pending state change, wait for it to complete */
1799 if (!GST_STATE_TIMED_WAIT (element, timeval)) {
1800 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "timed out");
1801 /* timeout triggered */
1802 ret = GST_STATE_CHANGE_ASYNC;
1804 if (cookie != element->state_cookie)
1807 /* could be success or failure */
1808 if (old_pending == GST_STATE (element)) {
1809 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "got success");
1810 ret = GST_STATE_CHANGE_SUCCESS;
1812 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "got failure");
1813 ret = GST_STATE_CHANGE_FAILURE;
1817 /* if nothing is pending anymore we can return SUCCESS */
1818 if (GST_STATE_PENDING (element) == GST_STATE_VOID_PENDING) {
1819 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "nothing pending");
1820 ret = GST_STATE_CHANGE_SUCCESS;
1825 *state = GST_STATE (element);
1827 *pending = GST_STATE_PENDING (element);
1829 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
1830 "state current: %s, pending: %s, result: %s",
1831 gst_element_state_get_name (GST_STATE (element)),
1832 gst_element_state_get_name (GST_STATE_PENDING (element)),
1833 gst_element_state_change_return_get_name (ret));
1834 GST_OBJECT_UNLOCK (element);
1841 *state = GST_STATE_VOID_PENDING;
1843 *pending = GST_STATE_VOID_PENDING;
1845 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "get_state() interruped");
1847 GST_OBJECT_UNLOCK (element);
1849 return GST_STATE_CHANGE_FAILURE;
1854 * gst_element_get_state:
1855 * @element: a #GstElement to get the state of.
1856 * @state: a pointer to #GstState to hold the state. Can be %NULL.
1857 * @pending: a pointer to #GstState to hold the pending state.
1859 * @timeout: a #GstClockTime to specify the timeout for an async
1860 * state change or %GST_CLOCK_TIME_NONE for infinite timeout.
1862 * Gets the state of the element.
1864 * For elements that performed an ASYNC state change, as reported by
1865 * gst_element_set_state(), this function will block up to the
1866 * specified timeout value for the state change to complete.
1867 * If the element completes the state change or goes into
1868 * an error, this function returns immediately with a return value of
1869 * %GST_STATE_CHANGE_SUCCESS or %GST_STATE_CHANGE_FAILURE respectively.
1871 * For elements that did not return %GST_STATE_CHANGE_ASYNC, this function
1872 * returns the current and pending state immediately.
1874 * This function returns %GST_STATE_CHANGE_NO_PREROLL if the element
1875 * successfully changed its state but is not able to provide data yet.
1876 * This mostly happens for live sources that only produce data in the PLAYING
1877 * state. While the state change return is equivalent to
1878 * %GST_STATE_CHANGE_SUCCESS, it is returned to the application to signal that
1879 * some sink elements might not be able to complete their state change because
1880 * an element is not producing data to complete the preroll. When setting the
1881 * element to playing, the preroll will complete and playback will start.
1883 * Returns: %GST_STATE_CHANGE_SUCCESS if the element has no more pending state
1884 * and the last state change succeeded, %GST_STATE_CHANGE_ASYNC if the
1885 * element is still performing a state change or
1886 * %GST_STATE_CHANGE_FAILURE if the last state change failed.
1890 GstStateChangeReturn
1891 gst_element_get_state (GstElement * element,
1892 GstState * state, GstState * pending, GstClockTime timeout)
1894 GstElementClass *oclass;
1895 GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE;
1897 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
1899 oclass = GST_ELEMENT_GET_CLASS (element);
1901 if (oclass->get_state)
1902 result = (oclass->get_state) (element, state, pending, timeout);
1908 * gst_element_abort_state:
1909 * @element: a #GstElement to abort the state of.
1911 * Abort the state change of the element. This function is used
1912 * by elements that do asynchronous state changes and find out
1913 * something is wrong.
1915 * This function should be called with the STATE_LOCK held.
1920 gst_element_abort_state (GstElement * element)
1924 #ifndef GST_DISABLE_GST_DEBUG
1928 g_return_if_fail (GST_IS_ELEMENT (element));
1930 GST_OBJECT_LOCK (element);
1931 pending = GST_STATE_PENDING (element);
1933 if (pending == GST_STATE_VOID_PENDING ||
1934 GST_STATE_RETURN (element) == GST_STATE_CHANGE_FAILURE)
1935 goto nothing_aborted;
1937 #ifndef GST_DISABLE_GST_DEBUG
1938 old_state = GST_STATE (element);
1940 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
1941 "aborting state from %s to %s", gst_element_state_get_name (old_state),
1942 gst_element_state_get_name (pending));
1946 GST_STATE_RETURN (element) = GST_STATE_CHANGE_FAILURE;
1948 GST_STATE_BROADCAST (element);
1949 GST_OBJECT_UNLOCK (element);
1955 GST_OBJECT_UNLOCK (element);
1961 * gst_element_continue_state:
1962 * @element: a #GstElement to continue the state change of.
1963 * @ret: The previous state return value
1965 * Commit the state change of the element and proceed to the next
1966 * pending state if any. This function is used
1967 * by elements that do asynchronous state changes.
1968 * The core will normally call this method automatically when an
1969 * element returned %GST_STATE_CHANGE_SUCCESS from the state change function.
1971 * If after calling this method the element still has not reached
1972 * the pending state, the next state change is performed.
1974 * This method is used internally and should normally not be called by plugins
1977 * Returns: The result of the commit state change.
1981 GstStateChangeReturn
1982 gst_element_continue_state (GstElement * element, GstStateChangeReturn ret)
1985 GstState old_ret, old_state, old_next;
1986 GstState current, next;
1987 GstMessage *message;
1988 GstStateChange transition;
1990 GST_OBJECT_LOCK (element);
1991 old_ret = (GstState) GST_STATE_RETURN (element);
1992 GST_STATE_RETURN (element) = ret;
1993 pending = GST_STATE_PENDING (element);
1995 /* check if there is something to commit */
1996 if (pending == GST_STATE_VOID_PENDING)
1997 goto nothing_pending;
1999 old_state = GST_STATE (element);
2000 /* this is the state we should go to next */
2001 old_next = GST_STATE_NEXT (element);
2002 /* update current state */
2003 current = GST_STATE (element) = old_next;
2005 /* see if we reached the final state */
2006 if (pending == current)
2009 next = GST_STATE_GET_NEXT (current, pending);
2010 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2012 GST_STATE_NEXT (element) = next;
2014 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2015 GST_OBJECT_UNLOCK (element);
2017 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2018 "committing state from %s to %s, pending %s",
2019 gst_element_state_get_name (old_state),
2020 gst_element_state_get_name (old_next),
2021 gst_element_state_get_name (pending));
2023 message = gst_message_new_state_changed (GST_OBJECT_CAST (element),
2024 old_state, old_next, pending);
2025 gst_element_post_message (element, message);
2027 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2028 "continue state change %s to %s, final %s",
2029 gst_element_state_get_name (current),
2030 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2032 ret = gst_element_change_state (element, transition);
2038 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "nothing pending");
2039 GST_OBJECT_UNLOCK (element);
2044 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
2045 GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING;
2047 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "completed state change");
2048 GST_OBJECT_UNLOCK (element);
2050 /* don't post silly messages with the same state. This can happen
2051 * when an element state is changed to what it already was. For bins
2052 * this can be the result of a lost state, which we check with the
2053 * previous return value.
2054 * We do signal the cond though as a _get_state() might be blocking
2056 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2057 message = gst_message_new_state_changed (GST_OBJECT_CAST (element),
2058 old_state, old_next, GST_STATE_VOID_PENDING);
2059 gst_element_post_message (element, message);
2062 GST_STATE_BROADCAST (element);
2069 * gst_element_lost_state:
2070 * @element: a #GstElement the state is lost of
2072 * Brings the element to the lost state. The current state of the
2073 * element is copied to the pending state so that any call to
2074 * gst_element_get_state() will return %GST_STATE_CHANGE_ASYNC.
2076 * This is mostly used for elements that lost their preroll buffer
2077 * in the %GST_STATE_PAUSED state after a flush, they become %GST_STATE_PAUSED
2078 * again if a new preroll buffer is queued.
2079 * This function can only be called when the element is currently
2080 * not in error or an async state change.
2082 * This function is used internally and should normally not be called from
2083 * plugins or applications.
2088 gst_element_lost_state (GstElement * element)
2090 GstState current_state;
2091 GstMessage *message;
2093 g_return_if_fail (GST_IS_ELEMENT (element));
2095 GST_OBJECT_LOCK (element);
2096 if (GST_STATE_PENDING (element) != GST_STATE_VOID_PENDING ||
2097 GST_STATE_RETURN (element) == GST_STATE_CHANGE_FAILURE)
2100 current_state = GST_STATE (element);
2102 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2103 "lost state of %s", gst_element_state_get_name (current_state));
2105 GST_STATE_NEXT (element) = current_state;
2106 GST_STATE_PENDING (element) = current_state;
2107 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2108 GST_OBJECT_UNLOCK (element);
2110 message = gst_message_new_state_changed (GST_OBJECT_CAST (element),
2111 current_state, current_state, current_state);
2112 gst_element_post_message (element, message);
2114 /* and mark us dirty */
2115 message = gst_message_new_state_dirty (GST_OBJECT_CAST (element));
2116 gst_element_post_message (element, message);
2122 GST_OBJECT_UNLOCK (element);
2128 * gst_element_set_state:
2129 * @element: a #GstElement to change state of.
2130 * @state: the element's new #GstState.
2132 * Sets the state of the element. This function will try to set the
2133 * requested state by going through all the intermediary states and calling
2134 * the class's state change function for each.
2136 * This function can return #GST_STATE_CHANGE_ASYNC, in which case the
2137 * element will perform the remainder of the state change asynchronously in
2139 * An application can use gst_element_get_state() to wait for the completion
2140 * of the state change or it can wait for a state change message on the bus.
2142 * Returns: Result of the state change using #GstStateChangeReturn.
2146 GstStateChangeReturn
2147 gst_element_set_state (GstElement * element, GstState state)
2149 GstElementClass *oclass;
2150 GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE;
2152 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
2154 oclass = GST_ELEMENT_GET_CLASS (element);
2156 if (oclass->set_state)
2157 result = (oclass->set_state) (element, state);
2163 * default set state function, calculates the next state based
2164 * on current state and calls the change_state function
2166 static GstStateChangeReturn
2167 gst_element_set_state_func (GstElement * element, GstState state)
2169 GstState current, next, old_pending;
2170 GstStateChangeReturn ret;
2171 GstStateChange transition;
2172 GstStateChangeReturn old_ret;
2174 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
2176 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "set_state to %s",
2177 gst_element_state_get_name (state));
2179 /* state lock is taken to protect the set_state() and get_state()
2180 * procedures, it does not lock any variables. */
2181 GST_STATE_LOCK (element);
2183 /* now calculate how to get to the new state */
2184 GST_OBJECT_LOCK (element);
2185 old_ret = GST_STATE_RETURN (element);
2186 /* previous state change returned an error, remove all pending
2187 * and next states */
2188 if (old_ret == GST_STATE_CHANGE_FAILURE) {
2189 GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING;
2190 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
2191 GST_STATE_RETURN (element) = GST_STATE_CHANGE_SUCCESS;
2194 current = GST_STATE (element);
2195 next = GST_STATE_NEXT (element);
2196 old_pending = GST_STATE_PENDING (element);
2197 /* increment state cookie so that we can track each state change */
2198 element->state_cookie++;
2200 /* this is the (new) state we should go to */
2201 GST_STATE_PENDING (element) = state;
2203 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2204 "current %s, old_pending %s, next %s, old return %s",
2205 gst_element_state_get_name (current),
2206 gst_element_state_get_name (old_pending),
2207 gst_element_state_get_name (next),
2208 gst_element_state_change_return_get_name (old_ret));
2210 /* if the element was busy doing a state change, we just update the
2211 * target state, it'll get to it async then. */
2212 if (old_pending != GST_STATE_VOID_PENDING) {
2213 /* upwards state change will happen ASYNC */
2214 if (old_pending <= state)
2216 /* element is going to this state already */
2217 else if (next == state)
2219 /* element was performing an ASYNC upward state change and
2220 * we request to go downward again. Start from the next pending
2222 else if (next > state
2223 && GST_STATE_RETURN (element) == GST_STATE_CHANGE_ASYNC) {
2227 next = GST_STATE_GET_NEXT (current, state);
2228 /* now we store the next state */
2229 GST_STATE_NEXT (element) = next;
2230 /* mark busy, we need to check that there is actually a state change
2231 * to be done else we could accidentally override SUCCESS/NO_PREROLL and
2232 * the default element change_state function has no way to know what the
2233 * old value was... could consider this a FIXME...*/
2234 if (current != next)
2235 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2237 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2239 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2240 "%s: setting state from %s to %s",
2241 (next != state ? "intermediate" : "final"),
2242 gst_element_state_get_name (current), gst_element_state_get_name (next));
2244 /* now signal any waiters, they will error since the cookie was increased */
2245 GST_STATE_BROADCAST (element);
2247 GST_OBJECT_UNLOCK (element);
2249 ret = gst_element_change_state (element, transition);
2251 GST_STATE_UNLOCK (element);
2253 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "returned %s",
2254 gst_element_state_change_return_get_name (ret));
2260 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2261 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2262 "element was busy with async state change");
2263 GST_OBJECT_UNLOCK (element);
2265 GST_STATE_UNLOCK (element);
2267 return GST_STATE_CHANGE_ASYNC;
2271 /* with STATE_LOCK */
2272 static GstStateChangeReturn
2273 gst_element_change_state (GstElement * element, GstStateChange transition)
2275 GstElementClass *oclass;
2276 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
2280 oclass = GST_ELEMENT_GET_CLASS (element);
2282 /* start with the current state. */
2283 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2284 next = GST_STATE_TRANSITION_NEXT (transition);
2286 /* call the state change function so it can set the state */
2287 if (oclass->change_state)
2288 ret = (oclass->change_state) (element, transition);
2290 ret = GST_STATE_CHANGE_FAILURE;
2293 case GST_STATE_CHANGE_FAILURE:
2294 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2295 "have FAILURE change_state return");
2296 /* state change failure */
2297 gst_element_abort_state (element);
2299 case GST_STATE_CHANGE_ASYNC:
2300 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2301 "element will change state ASYNC");
2303 /* if we go upwards, we give the app a change to wait for
2308 /* else we just continue the state change downwards */
2309 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2310 "forcing commit state %s < %s",
2311 gst_element_state_get_name (current),
2312 gst_element_state_get_name (next));
2314 ret = gst_element_continue_state (element, GST_STATE_CHANGE_SUCCESS);
2316 case GST_STATE_CHANGE_SUCCESS:
2317 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2318 "element changed state SUCCESS");
2319 /* we can commit the state now which will proceeed to
2321 ret = gst_element_continue_state (element, ret);
2323 case GST_STATE_CHANGE_NO_PREROLL:
2324 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2325 "element changed state NO_PREROLL");
2326 /* we can commit the state now which will proceeed to
2328 ret = gst_element_continue_state (element, ret);
2331 goto invalid_return;
2334 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "exit state change %d", ret);
2339 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "exit async state change %d",
2347 GST_OBJECT_LOCK (element);
2348 /* somebody added a GST_STATE_ and forgot to do stuff here ! */
2349 g_critical ("%s: unknown return value %d from a state change function",
2350 GST_ELEMENT_NAME (element), ret);
2352 /* we are in error now */
2353 ret = GST_STATE_CHANGE_FAILURE;
2354 GST_STATE_RETURN (element) = ret;
2355 GST_OBJECT_UNLOCK (element);
2361 /* gst_iterator_fold functions for pads_activate
2362 * Note how we don't stop the iterator when we fail an activation. This is
2363 * probably a FIXME since when one pad activation fails, we don't want to
2364 * continue our state change. */
2366 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2368 if (!gst_pad_set_active (pad, *active))
2369 g_value_set_boolean (ret, FALSE);
2371 /* unref the object that was reffed for us by _fold */
2372 gst_object_unref (pad);
2376 /* set the caps on the pad to NULL */
2378 clear_caps (GstPad * pad, GValue * ret, gboolean * active)
2380 gst_pad_set_caps (pad, NULL);
2381 gst_object_unref (pad);
2385 /* returns false on error or early cutout (will never happen because the fold
2386 * function always returns TRUE, see FIXME above) of the fold, true if all
2387 * pads in @iter were (de)activated successfully. */
2389 iterator_activate_fold_with_resync (GstIterator * iter,
2390 GstIteratorFoldFunction func, gpointer user_data)
2392 GstIteratorResult ires;
2395 /* no need to unset this later, it's just a boolean */
2396 g_value_init (&ret, G_TYPE_BOOLEAN);
2397 g_value_set_boolean (&ret, TRUE);
2400 ires = gst_iterator_fold (iter, func, &ret, user_data);
2402 case GST_ITERATOR_RESYNC:
2403 /* need to reset the result again */
2404 g_value_set_boolean (&ret, TRUE);
2405 gst_iterator_resync (iter);
2407 case GST_ITERATOR_DONE:
2408 /* all pads iterated, return collected value */
2411 /* iterator returned _ERROR or premature end with _OK,
2412 * mark an error and exit */
2413 g_value_set_boolean (&ret, FALSE);
2418 /* return collected value */
2419 return g_value_get_boolean (&ret);
2422 /* is called with STATE_LOCK
2424 * Pads are activated from source pads to sinkpads.
2427 gst_element_pads_activate (GstElement * element, gboolean active)
2432 GST_DEBUG_OBJECT (element, "pads_activate with active %d", active);
2434 iter = gst_element_iterate_src_pads (element);
2436 iterator_activate_fold_with_resync (iter,
2437 (GstIteratorFoldFunction) activate_pads, &active);
2438 gst_iterator_free (iter);
2439 if (G_UNLIKELY (!res))
2442 iter = gst_element_iterate_sink_pads (element);
2444 iterator_activate_fold_with_resync (iter,
2445 (GstIteratorFoldFunction) activate_pads, &active);
2446 gst_iterator_free (iter);
2447 if (G_UNLIKELY (!res))
2451 /* clear the caps on all pads, this should never fail */
2452 iter = gst_element_iterate_pads (element);
2454 iterator_activate_fold_with_resync (iter,
2455 (GstIteratorFoldFunction) clear_caps, &active);
2456 gst_iterator_free (iter);
2457 if (G_UNLIKELY (!res))
2461 GST_DEBUG_OBJECT (element, "pads_activate successful");
2468 GST_DEBUG_OBJECT (element, "source pads_activate failed");
2473 GST_DEBUG_OBJECT (element, "sink pads_activate failed");
2478 GST_DEBUG_OBJECT (element, "failed to clear caps on pads");
2483 /* is called with STATE_LOCK */
2484 static GstStateChangeReturn
2485 gst_element_change_state_func (GstElement * element, GstStateChange transition)
2487 GstState state, next;
2488 GstStateChangeReturn result = GST_STATE_CHANGE_SUCCESS;
2490 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
2492 state = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2493 next = GST_STATE_TRANSITION_NEXT (transition);
2495 /* if the element already is in the given state, we just return success */
2496 if (next == GST_STATE_VOID_PENDING || state == next)
2499 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element,
2500 "default handler tries setting state from %s to %s (%04x)",
2501 gst_element_state_get_name (state),
2502 gst_element_state_get_name (next), transition);
2504 switch (transition) {
2505 case GST_STATE_CHANGE_NULL_TO_READY:
2507 case GST_STATE_CHANGE_READY_TO_PAUSED:
2508 if (!gst_element_pads_activate (element, TRUE)) {
2509 result = GST_STATE_CHANGE_FAILURE;
2512 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
2514 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
2516 case GST_STATE_CHANGE_PAUSED_TO_READY:
2517 case GST_STATE_CHANGE_READY_TO_NULL:
2518 /* deactivate pads in both cases, since they are activated on
2519 ready->paused but the element might not have made it to paused */
2520 if (!gst_element_pads_activate (element, FALSE)) {
2521 result = GST_STATE_CHANGE_FAILURE;
2523 gst_element_set_base_time (element, 0);
2527 /* this will catch real but unhandled state changes;
2528 * can only be caused by:
2529 * - a new state was added
2530 * - somehow the element was asked to jump across an intermediate state
2532 g_warning ("Unhandled state change from %s to %s",
2533 gst_element_state_get_name (state),
2534 gst_element_state_get_name (next));
2541 GST_OBJECT_LOCK (element);
2542 result = GST_STATE_RETURN (element);
2543 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2544 "element is already in the %s state",
2545 gst_element_state_get_name (state));
2546 GST_OBJECT_UNLOCK (element);
2553 * gst_element_get_factory:
2554 * @element: a #GstElement to request the element factory of.
2556 * Retrieves the factory that was used to create this element.
2558 * Returns: the #GstElementFactory used for creating this element.
2559 * no refcounting is needed.
2562 gst_element_get_factory (GstElement * element)
2564 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
2566 return GST_ELEMENT_GET_CLASS (element)->elementfactory;
2570 gst_element_dispose (GObject * object)
2572 GstElement *element = GST_ELEMENT (object);
2576 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "dispose");
2578 if (GST_STATE (element) != GST_STATE_NULL)
2581 g_return_if_fail (GST_STATE_PENDING (element) == GST_STATE_VOID_PENDING);
2583 GST_DEBUG_OBJECT (element, "removing %d pads", g_list_length (element->pads));
2584 /* first we break all our links with the outside */
2585 while (element->pads && element->pads->data) {
2586 /* don't call _remove_pad with NULL */
2587 gst_element_remove_pad (element, GST_PAD_CAST (element->pads->data));
2589 if (G_UNLIKELY (element->pads != 0)) {
2590 g_critical ("could not remove pads from element %s",
2591 GST_STR_NULL (GST_OBJECT_NAME (object)));
2594 GST_OBJECT_LOCK (element);
2595 clock_p = &element->clock;
2596 bus_p = &element->bus;
2597 gst_object_replace ((GstObject **) clock_p, NULL);
2598 gst_object_replace ((GstObject **) bus_p, NULL);
2599 GST_OBJECT_UNLOCK (element);
2601 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "parent class dispose");
2603 G_OBJECT_CLASS (parent_class)->dispose (object);
2611 ("\nTrying to dispose element %s, but it is not in the NULL state.\n"
2612 "You need to explicitly set elements to the NULL state before\n"
2613 "dropping the final reference, to allow them to clean up.\n",
2614 GST_OBJECT_NAME (element));
2620 gst_element_finalize (GObject * object)
2622 GstElement *element = GST_ELEMENT (object);
2624 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "finalize");
2626 GST_STATE_LOCK (element);
2627 if (element->state_cond)
2628 g_cond_free (element->state_cond);
2629 element->state_cond = NULL;
2630 GST_STATE_UNLOCK (element);
2631 g_static_rec_mutex_free (element->state_lock);
2632 g_free (element->state_lock);
2633 element->state_lock = NULL;
2635 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "finalize parent");
2637 G_OBJECT_CLASS (parent_class)->finalize (object);
2640 #ifndef GST_DISABLE_LOADSAVE
2642 * gst_element_save_thyself:
2643 * @element: a #GstElement to save.
2644 * @parent: the xml parent node.
2646 * Saves the element as part of the given XML structure.
2648 * Returns: the new #xmlNodePtr.
2651 gst_element_save_thyself (GstObject * object, xmlNodePtr parent)
2654 GstElementClass *oclass;
2655 GParamSpec **specs, *spec;
2658 GValue value = { 0, };
2659 GstElement *element;
2661 g_return_val_if_fail (GST_IS_ELEMENT (object), parent);
2663 element = GST_ELEMENT (object);
2665 oclass = GST_ELEMENT_GET_CLASS (element);
2667 xmlNewChild (parent, NULL, (xmlChar *) "name",
2668 (xmlChar *) GST_ELEMENT_NAME (element));
2670 if (oclass->elementfactory != NULL) {
2671 GstElementFactory *factory = (GstElementFactory *) oclass->elementfactory;
2673 xmlNewChild (parent, NULL, (xmlChar *) "type",
2674 (xmlChar *) GST_PLUGIN_FEATURE (factory)->name);
2678 specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (object), &nspecs);
2680 for (i = 0; i < nspecs; i++) {
2682 if (spec->flags & G_PARAM_READABLE) {
2686 g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (spec));
2688 g_object_get_property (G_OBJECT (element), spec->name, &value);
2689 param = xmlNewChild (parent, NULL, (xmlChar *) "param", NULL);
2690 xmlNewChild (param, NULL, (xmlChar *) "name", (xmlChar *) spec->name);
2692 if (G_IS_PARAM_SPEC_STRING (spec))
2693 contents = g_value_dup_string (&value);
2694 else if (G_IS_PARAM_SPEC_ENUM (spec))
2695 contents = g_strdup_printf ("%d", g_value_get_enum (&value));
2696 else if (G_IS_PARAM_SPEC_INT64 (spec))
2697 contents = g_strdup_printf ("%" G_GINT64_FORMAT,
2698 g_value_get_int64 (&value));
2700 contents = g_strdup_value_contents (&value);
2702 xmlNewChild (param, NULL, (xmlChar *) "value", (xmlChar *) contents);
2705 g_value_unset (&value);
2711 pads = GST_ELEMENT_PADS (element);
2714 GstPad *pad = GST_PAD_CAST (pads->data);
2716 /* figure out if it's a direct pad or a ghostpad */
2717 if (GST_ELEMENT (GST_OBJECT_PARENT (pad)) == element) {
2718 xmlNodePtr padtag = xmlNewChild (parent, NULL, (xmlChar *) "pad", NULL);
2720 gst_object_save_thyself (GST_OBJECT_CAST (pad), padtag);
2722 pads = g_list_next (pads);
2729 gst_element_restore_thyself (GstObject * object, xmlNodePtr self)
2731 xmlNodePtr children;
2732 GstElement *element;
2734 gchar *value = NULL;
2736 element = GST_ELEMENT (object);
2737 g_return_if_fail (element != NULL);
2740 children = self->xmlChildrenNode;
2742 if (!strcmp ((char *) children->name, "param")) {
2743 xmlNodePtr child = children->xmlChildrenNode;
2746 if (!strcmp ((char *) child->name, "name")) {
2747 name = (gchar *) xmlNodeGetContent (child);
2748 } else if (!strcmp ((char *) child->name, "value")) {
2749 value = (gchar *) xmlNodeGetContent (child);
2751 child = child->next;
2753 /* FIXME: can this just be g_object_set ? */
2754 gst_util_set_object_arg (G_OBJECT (element), name, value);
2755 /* g_object_set (G_OBJECT (element), name, value, NULL); */
2759 children = children->next;
2763 children = self->xmlChildrenNode;
2765 if (!strcmp ((char *) children->name, "pad")) {
2766 gst_pad_load_and_link (children, GST_OBJECT_CAST (element));
2768 children = children->next;
2771 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
2772 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
2774 #endif /* GST_DISABLE_LOADSAVE */
2777 gst_element_set_bus_func (GstElement * element, GstBus * bus)
2781 g_return_if_fail (GST_IS_ELEMENT (element));
2783 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, element, "setting bus to %p", bus);
2785 GST_OBJECT_LOCK (element);
2786 bus_p = &GST_ELEMENT_BUS (element);
2787 gst_object_replace ((GstObject **) bus_p, GST_OBJECT_CAST (bus));
2788 GST_OBJECT_UNLOCK (element);
2792 * gst_element_set_bus:
2793 * @element: a #GstElement to set the bus of.
2794 * @bus: the #GstBus to set.
2796 * Sets the bus of the element. Increases the refcount on the bus.
2797 * For internal use only, unless you're testing elements.
2802 gst_element_set_bus (GstElement * element, GstBus * bus)
2804 GstElementClass *oclass;
2806 g_return_if_fail (GST_IS_ELEMENT (element));
2808 oclass = GST_ELEMENT_GET_CLASS (element);
2810 if (oclass->set_bus)
2811 oclass->set_bus (element, bus);
2815 * gst_element_get_bus:
2816 * @element: a #GstElement to get the bus of.
2818 * Returns the bus of the element.
2820 * Returns: the element's #GstBus. unref after usage.
2825 gst_element_get_bus (GstElement * element)
2827 GstBus *result = NULL;
2829 g_return_val_if_fail (GST_IS_ELEMENT (element), result);
2831 GST_OBJECT_LOCK (element);
2832 if ((result = GST_ELEMENT_BUS (element)))
2833 gst_object_ref (result);
2834 GST_OBJECT_UNLOCK (element);
2836 GST_DEBUG_OBJECT (element, "got bus %" GST_PTR_FORMAT, result);