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., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
26 * @short_description: Abstract base class for all pipeline elements
27 * @see_also: #GstElementFactory, #GstPad
29 * GstElement is the abstract base class needed to construct an element that
30 * can be used in a GStreamer pipeline. Please refer to the plugin writers
31 * guide for more information on creating #GstElement subclasses.
33 * The name of a #GstElement can be get with gst_element_get_name() and set with
34 * gst_element_set_name(). For speed, GST_ELEMENT_NAME() can be used in the
35 * core when using the appropriate locking. Do not use this in plug-ins or
36 * applications in order to retain ABI compatibility.
38 * Elements can have pads (of the type #GstPad). These pads link to pads on
39 * other elements. #GstBuffer flow between these linked pads.
40 * A #GstElement has a #GList of #GstPad structures for all their input (or sink)
41 * and output (or source) pads.
42 * Core and plug-in writers can add and remove pads with gst_element_add_pad()
43 * and gst_element_remove_pad().
45 * An existing pad of an element can be retrieved by name with
46 * gst_element_get_static_pad(). A new dynamic pad can be created using
47 * gst_element_request_pad() with a #GstPadTemplate.
48 * An iterator of all pads can be retrieved with gst_element_iterate_pads().
50 * Elements can be linked through their pads.
51 * If the link is straightforward, use the gst_element_link()
52 * convenience function to link two elements, or gst_element_link_many()
53 * for more elements in a row.
54 * Use gst_element_link_filtered() to link two elements constrained by
55 * a specified set of #GstCaps.
56 * For finer control, use gst_element_link_pads() and
57 * gst_element_link_pads_filtered() to specify the pads to link on
58 * each element by name.
60 * Each element has a state (see #GstState). You can get and set the state
61 * of an element with gst_element_get_state() and gst_element_set_state().
62 * Setting a state triggers a #GstStateChange. To get a string representation
63 * of a #GstState, use gst_element_state_get_name().
65 * You can get and set a #GstClock on an element using gst_element_get_clock()
66 * and gst_element_set_clock().
67 * Some elements can provide a clock for the pipeline if
68 * the #GST_ELEMENT_FLAG_PROVIDE_CLOCK flag is set. With the
69 * gst_element_provide_clock() method one can retrieve the clock provided by
71 * Not all elements require a clock to operate correctly. If the
72 * #GST_ELEMENT_FLAG_REQUIRE_CLOCK() flag is set, a clock should be set on the
73 * element with gst_element_set_clock().
75 * Note that clock selection and distribution is normally handled by the
76 * toplevel #GstPipeline so the clock functions are only to be used in very
77 * specific situations.
80 #include "gst_private.h"
83 #include <gobject/gvaluecollector.h>
85 #include "gstelement.h"
86 #include "gstelementmetadata.h"
87 #include "gstenumtypes.h"
94 #include "gsttracerutils.h"
96 #include "gst-i18n-lib.h"
97 #include "glib-compat-private.h"
99 #ifndef GST_DISABLE_GST_DEBUG
100 #include "printf/printf.h"
103 /* Element signals and args */
119 static void gst_element_class_init (GstElementClass * klass);
120 static void gst_element_init (GstElement * element);
121 static void gst_element_base_class_init (gpointer g_class);
123 static void gst_element_constructed (GObject * object);
124 static void gst_element_dispose (GObject * object);
125 static void gst_element_finalize (GObject * object);
127 static GstStateChangeReturn gst_element_change_state_func (GstElement * element,
128 GstStateChange transition);
129 static GstStateChangeReturn gst_element_get_state_func (GstElement * element,
130 GstState * state, GstState * pending, GstClockTime timeout);
131 static GstStateChangeReturn gst_element_set_state_func (GstElement * element,
133 static gboolean gst_element_set_clock_func (GstElement * element,
135 static void gst_element_set_bus_func (GstElement * element, GstBus * bus);
136 static gboolean gst_element_post_message_default (GstElement * element,
137 GstMessage * message);
138 static void gst_element_set_context_default (GstElement * element,
139 GstContext * context);
141 static gboolean gst_element_default_send_event (GstElement * element,
143 static gboolean gst_element_default_query (GstElement * element,
146 static GstPadTemplate
147 * gst_element_class_get_request_pad_template (GstElementClass *
148 element_class, const gchar * name);
150 static void gst_element_call_async_func (gpointer data, gpointer user_data);
152 static GstObjectClass *parent_class = NULL;
153 static guint gst_element_signals[LAST_SIGNAL] = { 0 };
155 static GThreadPool *gst_element_pool = NULL;
157 /* this is used in gstelementfactory.c:gst_element_register() */
158 GQuark __gst_elementclass_factory = 0;
161 gst_element_get_type (void)
163 static volatile gsize gst_element_type = 0;
165 if (g_once_init_enter (&gst_element_type)) {
167 static const GTypeInfo element_info = {
168 sizeof (GstElementClass),
169 gst_element_base_class_init,
170 NULL, /* base_class_finalize */
171 (GClassInitFunc) gst_element_class_init,
176 (GInstanceInitFunc) gst_element_init,
180 _type = g_type_register_static (GST_TYPE_OBJECT, "GstElement",
181 &element_info, G_TYPE_FLAG_ABSTRACT);
183 __gst_elementclass_factory =
184 g_quark_from_static_string ("GST_ELEMENTCLASS_FACTORY");
185 g_once_init_leave (&gst_element_type, _type);
187 return gst_element_type;
191 gst_element_setup_thread_pool (void)
195 GST_DEBUG ("creating element thread pool");
197 g_thread_pool_new ((GFunc) gst_element_call_async_func, NULL, -1, FALSE,
200 g_critical ("could not alloc threadpool %s", err->message);
201 g_clear_error (&err);
206 gst_element_class_init (GstElementClass * klass)
208 GObjectClass *gobject_class;
210 gobject_class = (GObjectClass *) klass;
212 parent_class = g_type_class_peek_parent (klass);
215 * GstElement::pad-added:
216 * @gstelement: the object which received the signal
217 * @new_pad: the pad that has been added
219 * a new #GstPad has been added to the element. Note that this signal will
220 * usually be emitted from the context of the streaming thread. Also keep in
221 * mind that if you add new elements to the pipeline in the signal handler
222 * you will need to set them to the desired target state with
223 * gst_element_set_state() or gst_element_sync_state_with_parent().
225 gst_element_signals[PAD_ADDED] =
226 g_signal_new ("pad-added", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
227 G_STRUCT_OFFSET (GstElementClass, pad_added), NULL, NULL,
228 g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_PAD);
230 * GstElement::pad-removed:
231 * @gstelement: the object which received the signal
232 * @old_pad: the pad that has been removed
234 * a #GstPad has been removed from the element
236 gst_element_signals[PAD_REMOVED] =
237 g_signal_new ("pad-removed", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
238 G_STRUCT_OFFSET (GstElementClass, pad_removed), NULL, NULL,
239 g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_PAD);
241 * GstElement::no-more-pads:
242 * @gstelement: the object which received the signal
244 * This signals that the element will not generate more dynamic pads.
245 * Note that this signal will usually be emitted from the context of
246 * the streaming thread.
248 gst_element_signals[NO_MORE_PADS] =
249 g_signal_new ("no-more-pads", G_TYPE_FROM_CLASS (klass),
250 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstElementClass, no_more_pads), NULL,
251 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 0);
253 gobject_class->dispose = gst_element_dispose;
254 gobject_class->finalize = gst_element_finalize;
255 gobject_class->constructed = gst_element_constructed;
257 klass->change_state = GST_DEBUG_FUNCPTR (gst_element_change_state_func);
258 klass->set_state = GST_DEBUG_FUNCPTR (gst_element_set_state_func);
259 klass->get_state = GST_DEBUG_FUNCPTR (gst_element_get_state_func);
260 klass->set_clock = GST_DEBUG_FUNCPTR (gst_element_set_clock_func);
261 klass->set_bus = GST_DEBUG_FUNCPTR (gst_element_set_bus_func);
262 klass->query = GST_DEBUG_FUNCPTR (gst_element_default_query);
263 klass->send_event = GST_DEBUG_FUNCPTR (gst_element_default_send_event);
264 klass->numpadtemplates = 0;
265 klass->post_message = GST_DEBUG_FUNCPTR (gst_element_post_message_default);
266 klass->set_context = GST_DEBUG_FUNCPTR (gst_element_set_context_default);
268 klass->elementfactory = NULL;
270 gst_element_setup_thread_pool ();
274 gst_element_base_class_init (gpointer g_class)
276 GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
277 GList *node, *padtemplates;
279 /* Copy the element details here so elements can inherit the
280 * details from their base class and classes only need to set
281 * the details in class_init instead of base_init */
282 element_class->metadata =
283 element_class->metadata ? gst_structure_copy (element_class->metadata) :
284 gst_structure_new_empty ("metadata");
286 /* Copy the pad templates so elements inherit them
287 * from their base class but elements can add pad templates in class_init
288 * instead of base_init.
290 padtemplates = g_list_copy (element_class->padtemplates);
291 for (node = padtemplates; node != NULL; node = node->next) {
292 GstPadTemplate *tmpl = (GstPadTemplate *) node->data;
293 gst_object_ref (tmpl);
295 element_class->padtemplates = padtemplates;
297 /* set the factory, see gst_element_register() */
298 element_class->elementfactory =
299 g_type_get_qdata (G_TYPE_FROM_CLASS (element_class),
300 __gst_elementclass_factory);
301 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "type %s : factory %p",
302 G_OBJECT_CLASS_NAME (element_class), element_class->elementfactory);
306 gst_element_init (GstElement * element)
308 GST_STATE (element) = GST_STATE_NULL;
309 GST_STATE_TARGET (element) = GST_STATE_NULL;
310 GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING;
311 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
312 GST_STATE_RETURN (element) = GST_STATE_CHANGE_SUCCESS;
314 g_rec_mutex_init (&element->state_lock);
315 g_cond_init (&element->state_cond);
319 gst_element_constructed (GObject * object)
321 GST_TRACER_ELEMENT_NEW (GST_ELEMENT_CAST (object));
322 G_OBJECT_CLASS (parent_class)->constructed (object);
326 * gst_element_release_request_pad:
327 * @element: a #GstElement to release the request pad of.
328 * @pad: the #GstPad to release.
330 * Makes the element free the previously requested pad as obtained
331 * with gst_element_request_pad().
333 * This does not unref the pad. If the pad was created by using
334 * gst_element_request_pad(), gst_element_release_request_pad() needs to be
335 * followed by gst_object_unref() to free the @pad.
340 gst_element_release_request_pad (GstElement * element, GstPad * pad)
342 GstElementClass *oclass;
344 g_return_if_fail (GST_IS_ELEMENT (element));
345 g_return_if_fail (GST_IS_PAD (pad));
346 g_return_if_fail (GST_PAD_PAD_TEMPLATE (pad) == NULL ||
347 GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (pad)) ==
349 g_return_if_fail (GST_PAD_PARENT (pad) == element);
351 oclass = GST_ELEMENT_GET_CLASS (element);
353 /* if the element implements a custom release function we call that, else we
354 * simply remove the pad from the element */
355 if (oclass->release_pad)
356 oclass->release_pad (element, pad);
358 gst_element_remove_pad (element, pad);
362 * gst_element_provide_clock:
363 * @element: a #GstElement to query
365 * Get the clock provided by the given element.
366 * > An element is only required to provide a clock in the PAUSED
367 * > state. Some elements can provide a clock in other states.
369 * Returns: (transfer full) (nullable): the GstClock provided by the
370 * element or %NULL if no clock could be provided. Unref after usage.
375 gst_element_provide_clock (GstElement * element)
377 GstClock *result = NULL;
378 GstElementClass *oclass;
380 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
382 oclass = GST_ELEMENT_GET_CLASS (element);
384 if (oclass->provide_clock)
385 result = oclass->provide_clock (element);
391 gst_element_set_clock_func (GstElement * element, GstClock * clock)
395 GST_OBJECT_LOCK (element);
396 clock_p = &element->clock;
397 gst_object_replace ((GstObject **) clock_p, (GstObject *) clock);
398 GST_OBJECT_UNLOCK (element);
404 * gst_element_set_clock:
405 * @element: a #GstElement to set the clock for.
406 * @clock: the #GstClock to set for the element.
408 * Sets the clock for the element. This function increases the
409 * refcount on the clock. Any previously set clock on the object
412 * Returns: %TRUE if the element accepted the clock. An element can refuse a
413 * clock when it, for example, is not able to slave its internal clock to the
414 * @clock or when it requires a specific clock to operate.
419 gst_element_set_clock (GstElement * element, GstClock * clock)
421 GstElementClass *oclass;
422 gboolean res = FALSE;
424 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
425 g_return_val_if_fail (clock == NULL || GST_IS_CLOCK (clock), FALSE);
427 oclass = GST_ELEMENT_GET_CLASS (element);
429 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, element, "setting clock %p", clock);
431 if (oclass->set_clock)
432 res = oclass->set_clock (element, clock);
438 * gst_element_get_clock:
439 * @element: a #GstElement to get the clock of.
441 * Gets the currently configured clock of the element. This is the clock as was
442 * last set with gst_element_set_clock().
444 * Elements in a pipeline will only have their clock set when the
445 * pipeline is in the PLAYING state.
447 * Returns: (transfer full): the #GstClock of the element. unref after usage.
452 gst_element_get_clock (GstElement * element)
456 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
458 GST_OBJECT_LOCK (element);
459 if ((result = element->clock))
460 gst_object_ref (result);
461 GST_OBJECT_UNLOCK (element);
467 * gst_element_set_base_time:
468 * @element: a #GstElement.
469 * @time: the base time to set.
471 * Set the base time of an element. See gst_element_get_base_time().
476 gst_element_set_base_time (GstElement * element, GstClockTime time)
480 g_return_if_fail (GST_IS_ELEMENT (element));
482 GST_OBJECT_LOCK (element);
483 old = element->base_time;
484 element->base_time = time;
485 GST_OBJECT_UNLOCK (element);
487 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, element,
488 "set base_time=%" GST_TIME_FORMAT ", old %" GST_TIME_FORMAT,
489 GST_TIME_ARGS (time), GST_TIME_ARGS (old));
493 * gst_element_get_base_time:
494 * @element: a #GstElement.
496 * Returns the base time of the element. The base time is the
497 * absolute time of the clock when this element was last put to
498 * PLAYING. Subtracting the base time from the clock time gives
499 * the running time of the element.
501 * Returns: the base time of the element.
506 gst_element_get_base_time (GstElement * element)
510 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_CLOCK_TIME_NONE);
512 GST_OBJECT_LOCK (element);
513 result = element->base_time;
514 GST_OBJECT_UNLOCK (element);
520 * gst_element_set_start_time:
521 * @element: a #GstElement.
522 * @time: the base time to set.
524 * Set the start time of an element. The start time of the element is the
525 * running time of the element when it last went to the PAUSED state. In READY
526 * or after a flushing seek, it is set to 0.
528 * Toplevel elements like #GstPipeline will manage the start_time and
529 * base_time on its children. Setting the start_time to #GST_CLOCK_TIME_NONE
530 * on such a toplevel element will disable the distribution of the base_time to
531 * the children and can be useful if the application manages the base_time
532 * itself, for example if you want to synchronize capture from multiple
533 * pipelines, and you can also ensure that the pipelines have the same clock.
538 gst_element_set_start_time (GstElement * element, GstClockTime time)
542 g_return_if_fail (GST_IS_ELEMENT (element));
544 GST_OBJECT_LOCK (element);
545 old = GST_ELEMENT_START_TIME (element);
546 GST_ELEMENT_START_TIME (element) = time;
547 GST_OBJECT_UNLOCK (element);
549 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, element,
550 "set start_time=%" GST_TIME_FORMAT ", old %" GST_TIME_FORMAT,
551 GST_TIME_ARGS (time), GST_TIME_ARGS (old));
555 * gst_element_get_start_time:
556 * @element: a #GstElement.
558 * Returns the start time of the element. The start time is the
559 * running time of the clock when this element was last put to PAUSED.
561 * Usually the start_time is managed by a toplevel element such as
566 * Returns: the start time of the element.
569 gst_element_get_start_time (GstElement * element)
573 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_CLOCK_TIME_NONE);
575 GST_OBJECT_LOCK (element);
576 result = GST_ELEMENT_START_TIME (element);
577 GST_OBJECT_UNLOCK (element);
584 * gst_element_set_index:
585 * @element: a #GstElement.
586 * @index: (transfer none): a #GstIndex.
588 * Set @index on the element. The refcount of the index
589 * will be increased, any previously set index is unreffed.
594 gst_element_set_index (GstElement * element, GstIndex * index)
596 GstElementClass *oclass;
598 g_return_if_fail (GST_IS_ELEMENT (element));
599 g_return_if_fail (index == NULL || GST_IS_INDEX (index));
601 oclass = GST_ELEMENT_GET_CLASS (element);
603 if (oclass->set_index)
604 oclass->set_index (element, index);
608 * gst_element_get_index:
609 * @element: a #GstElement.
611 * Gets the index from the element.
613 * Returns: (transfer full) (nullable): a #GstIndex or %NULL when no
614 * index was set on the element. unref after usage.
619 gst_element_get_index (GstElement * element)
621 GstElementClass *oclass;
622 GstIndex *result = NULL;
624 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
626 oclass = GST_ELEMENT_GET_CLASS (element);
628 if (oclass->get_index)
629 result = oclass->get_index (element);
636 * gst_element_add_pad:
637 * @element: a #GstElement to add the pad to.
638 * @pad: (transfer floating): the #GstPad to add to the element.
640 * Adds a pad (link point) to @element. @pad's parent will be set to @element;
641 * see gst_object_set_parent() for refcounting information.
643 * Pads are not automatically activated so elements should perform the needed
644 * steps to activate the pad in case this pad is added in the PAUSED or PLAYING
645 * state. See gst_pad_set_active() for more information about activating pads.
647 * The pad and the element should be unlocked when calling this function.
649 * This function will emit the #GstElement::pad-added signal on the element.
651 * Returns: %TRUE if the pad could be added. This function can fail when
652 * a pad with the same name already existed or the pad already had another
658 gst_element_add_pad (GstElement * element, GstPad * pad)
663 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
664 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
666 /* locking pad to look at the name */
667 GST_OBJECT_LOCK (pad);
668 pad_name = g_strdup (GST_PAD_NAME (pad));
669 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "adding pad '%s'",
670 GST_STR_NULL (pad_name));
671 active = GST_PAD_IS_ACTIVE (pad);
672 GST_OBJECT_FLAG_SET (pad, GST_PAD_FLAG_NEED_PARENT);
673 GST_OBJECT_UNLOCK (pad);
675 /* then check to see if there's already a pad by that name here */
676 GST_OBJECT_LOCK (element);
677 if (G_UNLIKELY (!gst_object_check_uniqueness (element->pads, pad_name)))
680 /* try to set the pad's parent */
681 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (pad),
682 GST_OBJECT_CAST (element))))
685 /* check for active pads */
686 if (!active && (GST_STATE (element) > GST_STATE_READY ||
687 GST_STATE_NEXT (element) == GST_STATE_PAUSED)) {
688 g_warning ("adding inactive pad '%s' to running element '%s', you need to "
689 "use gst_pad_set_active(pad,TRUE) before adding it.",
690 GST_STR_NULL (pad_name), GST_ELEMENT_NAME (element));
691 gst_pad_set_active (pad, TRUE);
696 /* add it to the list */
697 switch (gst_pad_get_direction (pad)) {
699 element->srcpads = g_list_append (element->srcpads, pad);
700 element->numsrcpads++;
703 element->sinkpads = g_list_append (element->sinkpads, pad);
704 element->numsinkpads++;
709 element->pads = g_list_append (element->pads, pad);
711 element->pads_cookie++;
712 GST_OBJECT_UNLOCK (element);
714 /* emit the PAD_ADDED signal */
715 g_signal_emit (element, gst_element_signals[PAD_ADDED], 0, pad);
716 GST_TRACER_ELEMENT_ADD_PAD (element, pad);
722 g_critical ("Padname %s is not unique in element %s, not adding",
723 pad_name, GST_ELEMENT_NAME (element));
724 GST_OBJECT_UNLOCK (element);
726 gst_object_ref_sink (pad);
727 gst_object_unref (pad);
733 ("Pad %s already has parent when trying to add to element %s",
734 pad_name, GST_ELEMENT_NAME (element));
735 GST_OBJECT_UNLOCK (element);
741 GST_OBJECT_LOCK (pad);
743 ("Trying to add pad %s to element %s, but it has no direction",
744 GST_OBJECT_NAME (pad), GST_ELEMENT_NAME (element));
745 GST_OBJECT_UNLOCK (pad);
746 GST_OBJECT_UNLOCK (element);
752 * gst_element_remove_pad:
753 * @element: a #GstElement to remove pad from.
754 * @pad: (transfer full): the #GstPad to remove from the element.
756 * Removes @pad from @element. @pad will be destroyed if it has not been
757 * referenced elsewhere using gst_object_unparent().
759 * This function is used by plugin developers and should not be used
760 * by applications. Pads that were dynamically requested from elements
761 * with gst_element_request_pad() should be released with the
762 * gst_element_release_request_pad() function instead.
764 * Pads are not automatically deactivated so elements should perform the needed
765 * steps to deactivate the pad in case this pad is removed in the PAUSED or
766 * PLAYING state. See gst_pad_set_active() for more information about
769 * The pad and the element should be unlocked when calling this function.
771 * This function will emit the #GstElement::pad-removed signal on the element.
773 * Returns: %TRUE if the pad could be removed. Can return %FALSE if the
774 * pad does not belong to the provided element.
779 gst_element_remove_pad (GstElement * element, GstPad * pad)
783 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
784 g_return_val_if_fail (GST_IS_PAD (pad), FALSE);
786 /* locking pad to look at the name and parent */
787 GST_OBJECT_LOCK (pad);
788 GST_CAT_INFO_OBJECT (GST_CAT_ELEMENT_PADS, element, "removing pad '%s'",
789 GST_STR_NULL (GST_PAD_NAME (pad)));
791 if (G_UNLIKELY (GST_PAD_PARENT (pad) != element))
793 GST_OBJECT_UNLOCK (pad);
796 if ((peer = gst_pad_get_peer (pad))) {
797 /* window for MT unsafeness, someone else could unlink here
798 * and then we call unlink with wrong pads. The unlink
799 * function would catch this and safely return failed. */
800 if (GST_PAD_IS_SRC (pad))
801 gst_pad_unlink (pad, peer);
803 gst_pad_unlink (peer, pad);
805 gst_object_unref (peer);
808 GST_OBJECT_LOCK (element);
809 /* remove it from the list */
810 switch (gst_pad_get_direction (pad)) {
812 element->srcpads = g_list_remove (element->srcpads, pad);
813 element->numsrcpads--;
816 element->sinkpads = g_list_remove (element->sinkpads, pad);
817 element->numsinkpads--;
820 g_critical ("Removing pad without direction???");
823 element->pads = g_list_remove (element->pads, pad);
825 element->pads_cookie++;
826 GST_OBJECT_UNLOCK (element);
828 /* emit the PAD_REMOVED signal before unparenting and losing the last ref. */
829 g_signal_emit (element, gst_element_signals[PAD_REMOVED], 0, pad);
830 GST_TRACER_ELEMENT_REMOVE_PAD (element, pad);
831 gst_object_unparent (GST_OBJECT_CAST (pad));
838 /* locking order is element > pad */
839 GST_OBJECT_UNLOCK (pad);
841 GST_OBJECT_LOCK (element);
842 GST_OBJECT_LOCK (pad);
843 g_critical ("Padname %s:%s does not belong to element %s when removing",
844 GST_DEBUG_PAD_NAME (pad), GST_ELEMENT_NAME (element));
845 GST_OBJECT_UNLOCK (pad);
846 GST_OBJECT_UNLOCK (element);
852 * gst_element_no_more_pads:
853 * @element: a #GstElement
855 * Use this function to signal that the element does not expect any more pads
856 * to show up in the current pipeline. This function should be called whenever
857 * pads have been added by the element itself. Elements with #GST_PAD_SOMETIMES
858 * pad templates use this in combination with autopluggers to figure out that
859 * the element is done initializing its pads.
861 * This function emits the #GstElement::no-more-pads signal.
866 gst_element_no_more_pads (GstElement * element)
868 g_return_if_fail (GST_IS_ELEMENT (element));
870 g_signal_emit (element, gst_element_signals[NO_MORE_PADS], 0);
874 pad_compare_name (GstPad * pad1, const gchar * name)
878 GST_OBJECT_LOCK (pad1);
879 result = strcmp (GST_PAD_NAME (pad1), name);
880 GST_OBJECT_UNLOCK (pad1);
886 * gst_element_get_static_pad:
887 * @element: a #GstElement to find a static pad of.
888 * @name: the name of the static #GstPad to retrieve.
890 * Retrieves a pad from @element by name. This version only retrieves
891 * already-existing (i.e. 'static') pads.
893 * Returns: (transfer full) (nullable): the requested #GstPad if
894 * found, otherwise %NULL. unref after usage.
899 gst_element_get_static_pad (GstElement * element, const gchar * name)
902 GstPad *result = NULL;
904 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
905 g_return_val_if_fail (name != NULL, NULL);
907 GST_OBJECT_LOCK (element);
909 g_list_find_custom (element->pads, name, (GCompareFunc) pad_compare_name);
911 result = GST_PAD_CAST (find->data);
912 gst_object_ref (result);
915 if (result == NULL) {
916 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "no such pad '%s' in element \"%s\"",
917 name, GST_ELEMENT_NAME (element));
919 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "found pad %s:%s",
920 GST_ELEMENT_NAME (element), name);
922 GST_OBJECT_UNLOCK (element);
928 gst_element_is_valid_request_template_name (const gchar * templ_name,
932 const gchar *templ_name_ptr, *name_ptr;
933 gboolean next_specifier;
934 guint templ_postfix_len = 0, name_postfix_len = 0;
936 g_return_val_if_fail (templ_name != NULL, FALSE);
937 g_return_val_if_fail (name != NULL, FALSE);
939 /* Is this the template name? */
940 if (strcmp (templ_name, name) == 0)
943 /* otherwise check all the specifiers */
945 /* Because of sanity checks in gst_pad_template_new(), we know that %s
946 * and %d and %u, occurring at the template_name */
947 templ_name_ptr = strchr (templ_name, '%');
949 /* check characters ahead of the specifier */
950 if (!templ_name_ptr || strlen (name) <= templ_name_ptr - templ_name
951 || strncmp (templ_name, name, templ_name_ptr - templ_name) != 0) {
955 /* %s is not allowed for multiple specifiers, just a single specifier can be
956 * accepted in gst_pad_template_new() and can not be mixed with other
957 * specifier '%u' and '%d' */
958 if (*(templ_name_ptr + 1) == 's' && g_strcmp0 (templ_name, name) == 0) {
962 name_ptr = name + (templ_name_ptr - templ_name);
964 /* search next specifier, each of specifier should be separated by '_' */
965 templ_name = strchr (templ_name_ptr, '_');
966 name = strchr (name_ptr, '_');
968 /* don't match the number of specifiers */
969 if ((templ_name && !name) || (!templ_name && name))
972 if (templ_name && name)
973 next_specifier = TRUE;
975 next_specifier = FALSE;
977 /* check characters followed by the specifier */
978 if (*(templ_name_ptr + 2) != '\0' && *(templ_name_ptr + 2) != '_') {
979 if (next_specifier) {
980 templ_postfix_len = templ_name - (templ_name_ptr + 2);
981 name_postfix_len = name - name_ptr;
983 templ_postfix_len = strlen (templ_name_ptr + 2);
984 name_postfix_len = strlen (name_ptr);
987 if (strncmp (templ_name_ptr + 2,
988 name_ptr + name_postfix_len - templ_postfix_len,
989 templ_postfix_len) != 0) {
994 /* verify the specifier */
995 if (*(name_ptr) == '%') {
998 len = (next_specifier) ? name - name_ptr : strlen (name_ptr);
1000 if (strncmp (name_ptr, templ_name_ptr, len) != 0)
1004 const gchar *specifier;
1005 gchar *target = NULL;
1007 /* extract specifier when it has postfix characters */
1008 if (name_postfix_len > templ_postfix_len) {
1009 target = g_strndup (name_ptr, name_postfix_len - templ_postfix_len);
1011 specifier = target ? target : name_ptr;
1013 if (*(templ_name_ptr + 1) == 'd') {
1017 tmp = g_ascii_strtoll (specifier, &endptr, 10);
1018 if (tmp < G_MININT || tmp > G_MAXINT || (*endptr != '\0'
1021 } else if (*(templ_name_ptr + 1) == 'u') {
1025 tmp = g_ascii_strtoull (specifier, &endptr, 10);
1026 if (tmp > G_MAXUINT || (*endptr != '\0' && *endptr != '_'))
1033 /* otherwise we increment these from NULL to 1 */
1034 if (next_specifier) {
1038 } while (next_specifier);
1044 _gst_element_request_pad (GstElement * element, GstPadTemplate * templ,
1045 const gchar * name, const GstCaps * caps)
1047 GstPad *newpad = NULL;
1048 GstElementClass *oclass;
1050 oclass = GST_ELEMENT_GET_CLASS (element);
1052 #ifndef G_DISABLE_CHECKS
1053 /* Some sanity checking here */
1057 g_return_val_if_fail (gst_element_is_valid_request_template_name
1058 (templ->name_template, name), NULL);
1060 pad = gst_element_get_static_pad (element, name);
1062 gst_object_unref (pad);
1063 /* FIXME 2.0: Change this to g_return_val_if_fail() */
1064 g_critical ("Element %s already has a pad named %s, the behaviour of "
1065 " gst_element_get_request_pad() for existing pads is undefined!",
1066 GST_ELEMENT_NAME (element), name);
1071 if (oclass->request_new_pad)
1072 newpad = (oclass->request_new_pad) (element, templ, name, caps);
1075 gst_object_ref (newpad);
1081 * gst_element_get_request_pad:
1082 * @element: a #GstElement to find a request pad of.
1083 * @name: the name of the request #GstPad to retrieve.
1085 * Retrieves a pad from the element by name (e.g. "src_\%d"). This version only
1086 * retrieves request pads. The pad should be released with
1087 * gst_element_release_request_pad().
1089 * This method is slower than manually getting the pad template and calling
1090 * gst_element_request_pad() if the pads should have a specific name (e.g.
1091 * @name is "src_1" instead of "src_\%u").
1093 * Returns: (transfer full) (nullable): requested #GstPad if found,
1094 * otherwise %NULL. Release after usage.
1097 gst_element_get_request_pad (GstElement * element, const gchar * name)
1099 GstPadTemplate *templ = NULL;
1101 const gchar *req_name = NULL;
1102 gboolean templ_found = FALSE;
1104 GstElementClass *class;
1106 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1107 g_return_val_if_fail (name != NULL, NULL);
1109 class = GST_ELEMENT_GET_CLASS (element);
1111 templ = gst_element_class_get_request_pad_template (class, name);
1113 req_name = strstr (name, "%") ? NULL : name;
1116 /* there is no % in the name, try to find a matching template */
1117 list = class->padtemplates;
1118 while (!templ_found && list) {
1119 templ = (GstPadTemplate *) list->data;
1120 if (templ->presence == GST_PAD_REQUEST) {
1121 GST_CAT_DEBUG (GST_CAT_PADS, "comparing %s to %s", name,
1122 templ->name_template);
1123 if (gst_element_is_valid_request_template_name (templ->name_template,
1137 pad = _gst_element_request_pad (element, templ, req_name, NULL);
1143 * gst_element_request_pad: (virtual request_new_pad)
1144 * @element: a #GstElement to find a request pad of.
1145 * @templ: a #GstPadTemplate of which we want a pad of.
1146 * @name: (transfer none) (allow-none): the name of the request #GstPad
1147 * to retrieve. Can be %NULL.
1148 * @caps: (transfer none) (allow-none): the caps of the pad we want to
1149 * request. Can be %NULL.
1151 * Retrieves a request pad from the element according to the provided template.
1152 * Pad templates can be looked up using
1153 * gst_element_factory_get_static_pad_templates().
1155 * The pad should be released with gst_element_release_request_pad().
1157 * Returns: (transfer full) (nullable): requested #GstPad if found,
1158 * otherwise %NULL. Release after usage.
1161 gst_element_request_pad (GstElement * element,
1162 GstPadTemplate * templ, const gchar * name, const GstCaps * caps)
1164 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1165 g_return_val_if_fail (templ != NULL, NULL);
1166 g_return_val_if_fail (templ->presence == GST_PAD_REQUEST, NULL);
1168 return _gst_element_request_pad (element, templ, name, caps);
1171 static GstIterator *
1172 gst_element_iterate_pad_list (GstElement * element, GList ** padlist)
1174 GstIterator *result;
1176 GST_OBJECT_LOCK (element);
1177 result = gst_iterator_new_list (GST_TYPE_PAD,
1178 GST_OBJECT_GET_LOCK (element),
1179 &element->pads_cookie, padlist, (GObject *) element, NULL);
1180 GST_OBJECT_UNLOCK (element);
1186 * gst_element_iterate_pads:
1187 * @element: a #GstElement to iterate pads of.
1189 * Retrieves an iterator of @element's pads. The iterator should
1190 * be freed after usage. Also more specialized iterators exists such as
1191 * gst_element_iterate_src_pads() or gst_element_iterate_sink_pads().
1193 * The order of pads returned by the iterator will be the order in which
1194 * the pads were added to the element.
1196 * Returns: (transfer full): the #GstIterator of #GstPad.
1201 gst_element_iterate_pads (GstElement * element)
1203 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1205 return gst_element_iterate_pad_list (element, &element->pads);
1209 * gst_element_iterate_src_pads:
1210 * @element: a #GstElement.
1212 * Retrieves an iterator of @element's source pads.
1214 * The order of pads returned by the iterator will be the order in which
1215 * the pads were added to the element.
1217 * Returns: (transfer full): the #GstIterator of #GstPad.
1222 gst_element_iterate_src_pads (GstElement * element)
1224 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1226 return gst_element_iterate_pad_list (element, &element->srcpads);
1230 * gst_element_iterate_sink_pads:
1231 * @element: a #GstElement.
1233 * Retrieves an iterator of @element's sink pads.
1235 * The order of pads returned by the iterator will be the order in which
1236 * the pads were added to the element.
1238 * Returns: (transfer full): the #GstIterator of #GstPad.
1243 gst_element_iterate_sink_pads (GstElement * element)
1245 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1247 return gst_element_iterate_pad_list (element, &element->sinkpads);
1251 * gst_element_class_add_pad_template:
1252 * @klass: the #GstElementClass to add the pad template to.
1253 * @templ: (transfer floating): a #GstPadTemplate to add to the element class.
1255 * Adds a padtemplate to an element class. This is mainly used in the _class_init
1256 * functions of classes. If a pad template with the same name as an already
1257 * existing one is added the old one is replaced by the new one.
1259 * @templ's reference count will be incremented, and any floating
1260 * reference will be removed (see gst_object_ref_sink())
1264 gst_element_class_add_pad_template (GstElementClass * klass,
1265 GstPadTemplate * templ)
1267 GList *template_list = klass->padtemplates;
1269 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1270 g_return_if_fail (GST_IS_PAD_TEMPLATE (templ));
1272 /* If we already have a pad template with the same name replace the
1274 while (template_list) {
1275 GstPadTemplate *padtempl = (GstPadTemplate *) template_list->data;
1277 /* Found pad with the same name, replace and return */
1278 if (strcmp (templ->name_template, padtempl->name_template) == 0) {
1279 gst_object_ref_sink (padtempl);
1280 gst_object_unref (padtempl);
1281 template_list->data = templ;
1284 template_list = g_list_next (template_list);
1287 /* Take ownership of the floating ref */
1288 gst_object_ref_sink (templ);
1290 klass->padtemplates = g_list_append (klass->padtemplates, templ);
1291 klass->numpadtemplates++;
1295 * gst_element_class_add_static_pad_template:
1296 * @klass: the #GstElementClass to add the pad template to.
1297 * @static_templ: #GstStaticPadTemplate to add as pad template to the element class.
1299 * Adds a pad template to an element class based on the static pad template
1300 * @templ. This is mainly used in the _class_init functions of element
1301 * implementations. If a pad template with the same name already exists,
1302 * the old one is replaced by the new one.
1307 gst_element_class_add_static_pad_template (GstElementClass * klass,
1308 GstStaticPadTemplate * static_templ)
1310 gst_element_class_add_pad_template (klass,
1311 gst_static_pad_template_get (static_templ));
1315 * gst_element_class_add_metadata:
1316 * @klass: class to set metadata for
1317 * @key: the key to set
1318 * @value: the value to set
1320 * Set @key with @value as metadata in @klass.
1323 gst_element_class_add_metadata (GstElementClass * klass,
1324 const gchar * key, const gchar * value)
1326 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1327 g_return_if_fail (key != NULL);
1328 g_return_if_fail (value != NULL);
1330 gst_structure_set ((GstStructure *) klass->metadata,
1331 key, G_TYPE_STRING, value, NULL);
1335 * gst_element_class_add_static_metadata:
1336 * @klass: class to set metadata for
1337 * @key: the key to set
1338 * @value: the value to set
1340 * Set @key with @value as metadata in @klass.
1342 * Same as gst_element_class_add_metadata(), but @value must be a static string
1343 * or an inlined string, as it will not be copied. (GStreamer plugins will
1344 * be made resident once loaded, so this function can be used even from
1345 * dynamically loaded plugins.)
1348 gst_element_class_add_static_metadata (GstElementClass * klass,
1349 const gchar * key, const gchar * value)
1351 GValue val = G_VALUE_INIT;
1353 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1354 g_return_if_fail (key != NULL);
1355 g_return_if_fail (value != NULL);
1357 g_value_init (&val, G_TYPE_STRING);
1358 g_value_set_static_string (&val, value);
1359 gst_structure_take_value ((GstStructure *) klass->metadata, key, &val);
1363 * gst_element_class_set_metadata:
1364 * @klass: class to set metadata for
1365 * @longname: The long English name of the element. E.g. "File Sink"
1366 * @classification: String describing the type of element, as an unordered list
1367 * separated with slashes ('/'). See draft-klass.txt of the design docs
1368 * for more details and common types. E.g: "Sink/File"
1369 * @description: Sentence describing the purpose of the element.
1370 * E.g: "Write stream to a file"
1371 * @author: Name and contact details of the author(s). Use \n to separate
1372 * multiple author metadata. E.g: "Joe Bloggs <joe.blogs at foo.com>"
1374 * Sets the detailed information for a #GstElementClass.
1375 * > This function is for use in _class_init functions only.
1378 gst_element_class_set_metadata (GstElementClass * klass,
1379 const gchar * longname, const gchar * classification,
1380 const gchar * description, const gchar * author)
1382 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1383 g_return_if_fail (longname != NULL && *longname != '\0');
1384 g_return_if_fail (classification != NULL && *classification != '\0');
1385 g_return_if_fail (description != NULL && *description != '\0');
1386 g_return_if_fail (author != NULL && *author != '\0');
1388 gst_structure_id_set ((GstStructure *) klass->metadata,
1389 GST_QUARK (ELEMENT_METADATA_LONGNAME), G_TYPE_STRING, longname,
1390 GST_QUARK (ELEMENT_METADATA_KLASS), G_TYPE_STRING, classification,
1391 GST_QUARK (ELEMENT_METADATA_DESCRIPTION), G_TYPE_STRING, description,
1392 GST_QUARK (ELEMENT_METADATA_AUTHOR), G_TYPE_STRING, author, NULL);
1396 * gst_element_class_set_static_metadata:
1397 * @klass: class to set metadata for
1398 * @longname: The long English name of the element. E.g. "File Sink"
1399 * @classification: String describing the type of element, as an unordered list
1400 * separated with slashes ('/'). See draft-klass.txt of the design docs
1401 * for more details and common types. E.g: "Sink/File"
1402 * @description: Sentence describing the purpose of the element.
1403 * E.g: "Write stream to a file"
1404 * @author: Name and contact details of the author(s). Use \n to separate
1405 * multiple author metadata. E.g: "Joe Bloggs <joe.blogs at foo.com>"
1407 * Sets the detailed information for a #GstElementClass.
1409 * > This function is for use in _class_init functions only.
1411 * Same as gst_element_class_set_metadata(), but @longname, @classification,
1412 * @description, and @author must be static strings or inlined strings, as
1413 * they will not be copied. (GStreamer plugins will be made resident once
1414 * loaded, so this function can be used even from dynamically loaded plugins.)
1417 gst_element_class_set_static_metadata (GstElementClass * klass,
1418 const gchar * longname, const gchar * classification,
1419 const gchar * description, const gchar * author)
1421 GstStructure *s = (GstStructure *) klass->metadata;
1422 GValue val = G_VALUE_INIT;
1424 g_return_if_fail (GST_IS_ELEMENT_CLASS (klass));
1425 g_return_if_fail (longname != NULL && *longname != '\0');
1426 g_return_if_fail (classification != NULL && *classification != '\0');
1427 g_return_if_fail (description != NULL && *description != '\0');
1428 g_return_if_fail (author != NULL && *author != '\0');
1430 g_value_init (&val, G_TYPE_STRING);
1432 g_value_set_static_string (&val, longname);
1433 gst_structure_id_set_value (s, GST_QUARK (ELEMENT_METADATA_LONGNAME), &val);
1435 g_value_set_static_string (&val, classification);
1436 gst_structure_id_set_value (s, GST_QUARK (ELEMENT_METADATA_KLASS), &val);
1438 g_value_set_static_string (&val, description);
1439 gst_structure_id_set_value (s, GST_QUARK (ELEMENT_METADATA_DESCRIPTION),
1442 g_value_set_static_string (&val, author);
1443 gst_structure_id_take_value (s, GST_QUARK (ELEMENT_METADATA_AUTHOR), &val);
1447 * gst_element_class_get_metadata:
1448 * @klass: class to get metadata for
1449 * @key: the key to get
1451 * Get metadata with @key in @klass.
1453 * Returns: the metadata for @key.
1456 gst_element_class_get_metadata (GstElementClass * klass, const gchar * key)
1458 g_return_val_if_fail (GST_IS_ELEMENT_CLASS (klass), NULL);
1459 g_return_val_if_fail (key != NULL, NULL);
1461 return gst_structure_get_string ((GstStructure *) klass->metadata, key);
1465 * gst_element_get_metadata:
1466 * @element: class to get metadata for
1467 * @key: the key to get
1469 * Get metadata with @key in @klass.
1471 * Returns: the metadata for @key.
1476 gst_element_get_metadata (GstElement * element, const gchar * key)
1478 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1479 g_return_val_if_fail (key != NULL, NULL);
1481 return gst_element_class_get_metadata (GST_ELEMENT_GET_CLASS (element), key);
1485 * gst_element_class_get_pad_template_list:
1486 * @element_class: a #GstElementClass to get pad templates of.
1488 * Retrieves a list of the pad templates associated with @element_class. The
1489 * list must not be modified by the calling code.
1490 * > If you use this function in the #GInstanceInitFunc of an object class
1491 * > that has subclasses, make sure to pass the g_class parameter of the
1492 * > #GInstanceInitFunc here.
1494 * Returns: (transfer none) (element-type Gst.PadTemplate): the #GList of
1498 gst_element_class_get_pad_template_list (GstElementClass * element_class)
1500 g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL);
1502 return element_class->padtemplates;
1506 * gst_element_get_pad_template_list:
1507 * @element: a #GstElement to get pad templates of.
1509 * Retrieves a list of the pad templates associated with @element. The
1510 * list must not be modified by the calling code.
1512 * Returns: (transfer none) (element-type Gst.PadTemplate): the #GList of
1518 gst_element_get_pad_template_list (GstElement * element)
1520 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1523 gst_element_class_get_pad_template_list (GST_ELEMENT_GET_CLASS (element));
1527 * gst_element_class_get_pad_template:
1528 * @element_class: a #GstElementClass to get the pad template of.
1529 * @name: the name of the #GstPadTemplate to get.
1531 * Retrieves a padtemplate from @element_class with the given name.
1532 * > If you use this function in the #GInstanceInitFunc of an object class
1533 * > that has subclasses, make sure to pass the g_class parameter of the
1534 * > #GInstanceInitFunc here.
1536 * Returns: (transfer none) (nullable): the #GstPadTemplate with the
1537 * given name, or %NULL if none was found. No unreferencing is
1541 gst_element_class_get_pad_template (GstElementClass *
1542 element_class, const gchar * name)
1546 g_return_val_if_fail (GST_IS_ELEMENT_CLASS (element_class), NULL);
1547 g_return_val_if_fail (name != NULL, NULL);
1549 padlist = element_class->padtemplates;
1552 GstPadTemplate *padtempl = (GstPadTemplate *) padlist->data;
1554 if (strcmp (padtempl->name_template, name) == 0)
1557 padlist = g_list_next (padlist);
1564 * gst_element_get_pad_template:
1565 * @element: a #GstElement to get the pad template of.
1566 * @name: the name of the #GstPadTemplate to get.
1568 * Retrieves a padtemplate from @element with the given name.
1570 * Returns: (transfer none) (nullable): the #GstPadTemplate with the
1571 * given name, or %NULL if none was found. No unreferencing is
1577 gst_element_get_pad_template (GstElement * element, const gchar * name)
1579 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
1580 g_return_val_if_fail (name != NULL, NULL);
1582 return gst_element_class_get_pad_template (GST_ELEMENT_GET_CLASS (element),
1586 static GstPadTemplate *
1587 gst_element_class_get_request_pad_template (GstElementClass *
1588 element_class, const gchar * name)
1590 GstPadTemplate *tmpl;
1592 tmpl = gst_element_class_get_pad_template (element_class, name);
1593 if (tmpl != NULL && tmpl->presence == GST_PAD_REQUEST)
1599 /* get a random pad on element of the given direction.
1600 * The pad is random in a sense that it is the first pad that is (optionaly) linked.
1603 gst_element_get_random_pad (GstElement * element,
1604 gboolean need_linked, GstPadDirection dir)
1606 GstPad *result = NULL;
1609 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "getting a random pad");
1613 GST_OBJECT_LOCK (element);
1614 pads = element->srcpads;
1617 GST_OBJECT_LOCK (element);
1618 pads = element->sinkpads;
1621 goto wrong_direction;
1623 for (; pads; pads = g_list_next (pads)) {
1624 GstPad *pad = GST_PAD_CAST (pads->data);
1626 GST_OBJECT_LOCK (pad);
1627 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "checking pad %s:%s",
1628 GST_DEBUG_PAD_NAME (pad));
1630 if (need_linked && !GST_PAD_IS_LINKED (pad)) {
1631 /* if we require a linked pad, and it is not linked, continue the
1633 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "pad %s:%s is not linked",
1634 GST_DEBUG_PAD_NAME (pad));
1635 GST_OBJECT_UNLOCK (pad);
1638 /* found a pad, stop search */
1639 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "found pad %s:%s",
1640 GST_DEBUG_PAD_NAME (pad));
1641 GST_OBJECT_UNLOCK (pad);
1647 gst_object_ref (result);
1649 GST_OBJECT_UNLOCK (element);
1653 /* ERROR handling */
1656 g_warning ("unknown pad direction %d", dir);
1662 gst_element_default_send_event (GstElement * element, GstEvent * event)
1664 gboolean result = FALSE;
1667 pad = GST_EVENT_IS_DOWNSTREAM (event) ?
1668 gst_element_get_random_pad (element, TRUE, GST_PAD_SINK) :
1669 gst_element_get_random_pad (element, TRUE, GST_PAD_SRC);
1672 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS,
1673 "pushing %s event to random %s pad %s:%s",
1674 GST_EVENT_TYPE_NAME (event),
1675 (GST_PAD_DIRECTION (pad) == GST_PAD_SRC ? "src" : "sink"),
1676 GST_DEBUG_PAD_NAME (pad));
1678 result = gst_pad_send_event (pad, event);
1679 gst_object_unref (pad);
1681 GST_CAT_INFO (GST_CAT_ELEMENT_PADS, "can't send %s event on element %s",
1682 GST_EVENT_TYPE_NAME (event), GST_ELEMENT_NAME (element));
1683 gst_event_unref (event);
1689 * gst_element_send_event:
1690 * @element: a #GstElement to send the event to.
1691 * @event: (transfer full): the #GstEvent to send to the element.
1693 * Sends an event to an element. If the element doesn't implement an
1694 * event handler, the event will be pushed on a random linked sink pad for
1695 * downstream events or a random linked source pad for upstream events.
1697 * This function takes ownership of the provided event so you should
1698 * gst_event_ref() it if you want to reuse the event after this call.
1702 * Returns: %TRUE if the event was handled. Events that trigger a preroll (such
1703 * as flushing seeks and steps) will emit %GST_MESSAGE_ASYNC_DONE.
1706 gst_element_send_event (GstElement * element, GstEvent * event)
1708 GstElementClass *oclass;
1709 gboolean result = FALSE;
1711 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1712 g_return_val_if_fail (event != NULL, FALSE);
1714 oclass = GST_ELEMENT_GET_CLASS (element);
1716 GST_STATE_LOCK (element);
1717 if (oclass->send_event) {
1718 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "send %s event on element %s",
1719 GST_EVENT_TYPE_NAME (event), GST_ELEMENT_NAME (element));
1720 result = oclass->send_event (element, event);
1722 gst_event_unref (event);
1724 GST_STATE_UNLOCK (element);
1731 * @element: a #GstElement to send the event to.
1732 * @rate: The new playback rate
1733 * @format: The format of the seek values
1734 * @flags: The optional seek flags.
1735 * @start_type: The type and flags for the new start position
1736 * @start: The value of the new start position
1737 * @stop_type: The type and flags for the new stop position
1738 * @stop: The value of the new stop position
1740 * Sends a seek event to an element. See gst_event_new_seek() for the details of
1741 * the parameters. The seek event is sent to the element using
1742 * gst_element_send_event().
1746 * Returns: %TRUE if the event was handled. Flushing seeks will trigger a
1747 * preroll, which will emit %GST_MESSAGE_ASYNC_DONE.
1750 gst_element_seek (GstElement * element, gdouble rate, GstFormat format,
1751 GstSeekFlags flags, GstSeekType start_type, gint64 start,
1752 GstSeekType stop_type, gint64 stop)
1757 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1760 gst_event_new_seek (rate, format, flags, start_type, start, stop_type,
1762 result = gst_element_send_event (element, event);
1768 gst_element_default_query (GstElement * element, GstQuery * query)
1770 gboolean result = FALSE;
1773 pad = gst_element_get_random_pad (element, FALSE, GST_PAD_SRC);
1775 result = gst_pad_query (pad, query);
1777 gst_object_unref (pad);
1779 pad = gst_element_get_random_pad (element, TRUE, GST_PAD_SINK);
1781 GstPad *peer = gst_pad_get_peer (pad);
1784 result = gst_pad_query (peer, query);
1786 gst_object_unref (peer);
1788 gst_object_unref (pad);
1795 * gst_element_query:
1796 * @element: a #GstElement to perform the query on.
1797 * @query: (transfer none): the #GstQuery.
1799 * Performs a query on the given element.
1801 * For elements that don't implement a query handler, this function
1802 * forwards the query to a random srcpad or to the peer of a
1803 * random linked sinkpad of this element.
1805 * Please note that some queries might need a running pipeline to work.
1807 * Returns: %TRUE if the query could be performed.
1812 gst_element_query (GstElement * element, GstQuery * query)
1814 GstElementClass *klass;
1815 gboolean res = FALSE;
1817 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1818 g_return_val_if_fail (query != NULL, FALSE);
1820 GST_TRACER_ELEMENT_QUERY_PRE (element, query);
1822 klass = GST_ELEMENT_GET_CLASS (element);
1824 GST_CAT_DEBUG (GST_CAT_ELEMENT_PADS, "send query on element %s",
1825 GST_ELEMENT_NAME (element));
1826 res = klass->query (element, query);
1829 GST_TRACER_ELEMENT_QUERY_POST (element, query, res);
1834 gst_element_post_message_default (GstElement * element, GstMessage * message)
1837 gboolean result = FALSE;
1839 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1840 g_return_val_if_fail (message != NULL, FALSE);
1842 GST_OBJECT_LOCK (element);
1845 if (G_UNLIKELY (bus == NULL))
1848 gst_object_ref (bus);
1849 GST_OBJECT_UNLOCK (element);
1851 /* we release the element lock when posting the message so that any
1852 * (synchronous) message handlers can operate on the element */
1853 result = gst_bus_post (bus, message);
1854 gst_object_unref (bus);
1861 GST_CAT_DEBUG_OBJECT (GST_CAT_MESSAGE, element,
1862 "not posting message %p: no bus", message);
1863 GST_OBJECT_UNLOCK (element);
1864 gst_message_unref (message);
1870 * gst_element_post_message:
1871 * @element: a #GstElement posting the message
1872 * @message: (transfer full): a #GstMessage to post
1874 * Post a message on the element's #GstBus. This function takes ownership of the
1875 * message; if you want to access the message after this call, you should add an
1876 * additional reference before calling.
1878 * Returns: %TRUE if the message was successfully posted. The function returns
1879 * %FALSE if the element did not have a bus.
1884 gst_element_post_message (GstElement * element, GstMessage * message)
1886 GstElementClass *klass;
1887 gboolean res = FALSE;
1889 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1890 g_return_val_if_fail (message != NULL, FALSE);
1892 GST_TRACER_ELEMENT_POST_MESSAGE_PRE (element, message);
1894 klass = GST_ELEMENT_GET_CLASS (element);
1895 if (klass->post_message)
1896 res = klass->post_message (element, message);
1898 gst_message_unref (message);
1900 GST_TRACER_ELEMENT_POST_MESSAGE_POST (element, res);
1905 * _gst_element_error_printf:
1906 * @format: (allow-none): the printf-like format to use, or %NULL
1908 * This function is only used internally by the gst_element_error() macro.
1910 * Returns: (transfer full) (nullable): a newly allocated string, or
1911 * %NULL if the format was %NULL or ""
1916 _gst_element_error_printf (const gchar * format, ...)
1927 va_start (args, format);
1929 len = __gst_vasprintf (&buffer, format, args);
1940 * gst_element_message_full_with_details:
1941 * @element: a #GstElement to send message from
1942 * @type: the #GstMessageType
1943 * @domain: the GStreamer GError domain this message belongs to
1944 * @code: the GError code belonging to the domain
1945 * @text: (allow-none) (transfer full): an allocated text string to be used
1946 * as a replacement for the default message connected to code,
1948 * @debug: (allow-none) (transfer full): an allocated debug message to be
1949 * used as a replacement for the default debugging information,
1951 * @file: the source code file where the error was generated
1952 * @function: the source code function where the error was generated
1953 * @line: the source code line where the error was generated
1954 * @structure:(transfer full): optional details structure
1956 * Post an error, warning or info message on the bus from inside an element.
1958 * @type must be of #GST_MESSAGE_ERROR, #GST_MESSAGE_WARNING or
1959 * #GST_MESSAGE_INFO.
1963 void gst_element_message_full_with_details
1964 (GstElement * element, GstMessageType type,
1965 GQuark domain, gint code, gchar * text,
1966 gchar * debug, const gchar * file, const gchar * function, gint line,
1967 GstStructure * structure)
1969 GError *gerror = NULL;
1973 gboolean has_debug = TRUE;
1974 GstMessage *message = NULL;
1977 GST_CAT_DEBUG_OBJECT (GST_CAT_MESSAGE, element, "start");
1978 g_return_if_fail (GST_IS_ELEMENT (element));
1979 g_return_if_fail ((type == GST_MESSAGE_ERROR) ||
1980 (type == GST_MESSAGE_WARNING) || (type == GST_MESSAGE_INFO));
1982 /* check if we send the given text or the default error text */
1983 if ((text == NULL) || (text[0] == 0)) {
1984 /* text could have come from g_strdup_printf (""); */
1986 sent_text = gst_error_get_message (domain, code);
1990 /* construct a sent_debug with extra information from source */
1991 if ((debug == NULL) || (debug[0] == 0)) {
1992 /* debug could have come from g_strdup_printf (""); */
1996 name = gst_object_get_path_string (GST_OBJECT_CAST (element));
1998 sent_debug = g_strdup_printf ("%s(%d): %s (): %s:\n%s",
1999 file, line, function, name, debug);
2001 sent_debug = g_strdup_printf ("%s(%d): %s (): %s",
2002 file, line, function, name);
2006 /* create gerror and post message */
2007 GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posting message: %s",
2009 gerror = g_error_new_literal (domain, code, sent_text);
2012 case GST_MESSAGE_ERROR:
2014 gst_message_new_error_with_details (GST_OBJECT_CAST (element), gerror,
2015 sent_debug, structure);
2017 case GST_MESSAGE_WARNING:
2019 gst_message_new_warning_with_details (GST_OBJECT_CAST (element),
2020 gerror, sent_debug, structure);
2022 case GST_MESSAGE_INFO:
2024 gst_message_new_info_with_details (GST_OBJECT_CAST (element), gerror,
2025 sent_debug, structure);
2028 g_assert_not_reached ();
2032 gst_element_post_message (element, message);
2034 GST_CAT_INFO_OBJECT (GST_CAT_ERROR_SYSTEM, element, "posted %s message: %s",
2035 (type == GST_MESSAGE_ERROR ? "error" : "warning"), sent_text);
2038 g_error_free (gerror);
2039 g_free (sent_debug);
2044 * gst_element_message_full:
2045 * @element: a #GstElement to send message from
2046 * @type: the #GstMessageType
2047 * @domain: the GStreamer GError domain this message belongs to
2048 * @code: the GError code belonging to the domain
2049 * @text: (allow-none) (transfer full): an allocated text string to be used
2050 * as a replacement for the default message connected to code,
2052 * @debug: (allow-none) (transfer full): an allocated debug message to be
2053 * used as a replacement for the default debugging information,
2055 * @file: the source code file where the error was generated
2056 * @function: the source code function where the error was generated
2057 * @line: the source code line where the error was generated
2059 * Post an error, warning or info message on the bus from inside an element.
2061 * @type must be of #GST_MESSAGE_ERROR, #GST_MESSAGE_WARNING or
2062 * #GST_MESSAGE_INFO.
2066 void gst_element_message_full
2067 (GstElement * element, GstMessageType type,
2068 GQuark domain, gint code, gchar * text,
2069 gchar * debug, const gchar * file, const gchar * function, gint line)
2071 gst_element_message_full_with_details (element, type, domain, code, text,
2072 debug, file, function, line, NULL);
2076 * gst_element_is_locked_state:
2077 * @element: a #GstElement.
2079 * Checks if the state of an element is locked.
2080 * If the state of an element is locked, state changes of the parent don't
2081 * affect the element.
2082 * This way you can leave currently unused elements inside bins. Just lock their
2083 * state before changing the state from #GST_STATE_NULL.
2087 * Returns: %TRUE, if the element's state is locked.
2090 gst_element_is_locked_state (GstElement * element)
2094 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2096 GST_OBJECT_LOCK (element);
2097 result = GST_ELEMENT_IS_LOCKED_STATE (element);
2098 GST_OBJECT_UNLOCK (element);
2104 * gst_element_set_locked_state:
2105 * @element: a #GstElement
2106 * @locked_state: %TRUE to lock the element's state
2108 * Locks the state of an element, so state changes of the parent don't affect
2109 * this element anymore.
2113 * Returns: %TRUE if the state was changed, %FALSE if bad parameters were given
2114 * or the elements state-locking needed no change.
2117 gst_element_set_locked_state (GstElement * element, gboolean locked_state)
2121 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2123 GST_OBJECT_LOCK (element);
2124 old = GST_ELEMENT_IS_LOCKED_STATE (element);
2126 if (G_UNLIKELY (old == locked_state))
2130 GST_CAT_DEBUG (GST_CAT_STATES, "locking state of element %s",
2131 GST_ELEMENT_NAME (element));
2132 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_FLAG_LOCKED_STATE);
2134 GST_CAT_DEBUG (GST_CAT_STATES, "unlocking state of element %s",
2135 GST_ELEMENT_NAME (element));
2136 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_FLAG_LOCKED_STATE);
2138 GST_OBJECT_UNLOCK (element);
2144 GST_CAT_DEBUG (GST_CAT_STATES,
2145 "elements %s was already in locked state %d",
2146 GST_ELEMENT_NAME (element), old);
2147 GST_OBJECT_UNLOCK (element);
2154 * gst_element_sync_state_with_parent:
2155 * @element: a #GstElement.
2157 * Tries to change the state of the element to the same as its parent.
2158 * If this function returns %FALSE, the state of element is undefined.
2160 * Returns: %TRUE, if the element's state could be synced to the parent's state.
2165 gst_element_sync_state_with_parent (GstElement * element)
2169 GstStateChangeReturn ret;
2171 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
2173 if ((parent = GST_ELEMENT_CAST (gst_element_get_parent (element)))) {
2174 GstState parent_current, parent_pending;
2176 GST_OBJECT_LOCK (parent);
2177 parent_current = GST_STATE (parent);
2178 parent_pending = GST_STATE_PENDING (parent);
2179 GST_OBJECT_UNLOCK (parent);
2181 /* set to pending if there is one, else we set it to the current state of
2183 if (parent_pending != GST_STATE_VOID_PENDING)
2184 target = parent_pending;
2186 target = parent_current;
2188 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2189 "syncing state (%s) to parent %s %s (%s, %s)",
2190 gst_element_state_get_name (GST_STATE (element)),
2191 GST_ELEMENT_NAME (parent), gst_element_state_get_name (target),
2192 gst_element_state_get_name (parent_current),
2193 gst_element_state_get_name (parent_pending));
2195 ret = gst_element_set_state (element, target);
2196 if (ret == GST_STATE_CHANGE_FAILURE)
2199 gst_object_unref (parent);
2203 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "element has no parent");
2210 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2211 "syncing state failed (%s)",
2212 gst_element_state_change_return_get_name (ret));
2213 gst_object_unref (parent);
2219 static GstStateChangeReturn
2220 gst_element_get_state_func (GstElement * element,
2221 GstState * state, GstState * pending, GstClockTime timeout)
2223 GstStateChangeReturn ret = GST_STATE_CHANGE_FAILURE;
2224 GstState old_pending;
2226 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "getting state, timeout %"
2227 GST_TIME_FORMAT, GST_TIME_ARGS (timeout));
2229 GST_OBJECT_LOCK (element);
2230 ret = GST_STATE_RETURN (element);
2231 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "RETURN is %s",
2232 gst_element_state_change_return_get_name (ret));
2234 /* we got an error, report immediately */
2235 if (ret == GST_STATE_CHANGE_FAILURE)
2238 /* we got no_preroll, report immediately */
2239 if (ret == GST_STATE_CHANGE_NO_PREROLL)
2242 /* no need to wait async if we are not async */
2243 if (ret != GST_STATE_CHANGE_ASYNC)
2246 old_pending = GST_STATE_PENDING (element);
2247 if (old_pending != GST_STATE_VOID_PENDING) {
2251 /* get cookie to detect state changes during waiting */
2252 cookie = element->state_cookie;
2254 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2255 "waiting for element to commit state");
2257 /* we have a pending state change, wait for it to complete */
2258 if (timeout != GST_CLOCK_TIME_NONE) {
2260 /* make timeout absolute */
2261 end_time = g_get_monotonic_time () + (timeout / 1000);
2262 signaled = GST_STATE_WAIT_UNTIL (element, end_time);
2264 GST_STATE_WAIT (element);
2269 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "timed out");
2270 /* timeout triggered */
2271 ret = GST_STATE_CHANGE_ASYNC;
2273 if (cookie != element->state_cookie)
2276 /* could be success or failure */
2277 if (old_pending == GST_STATE (element)) {
2278 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "got success");
2279 ret = GST_STATE_CHANGE_SUCCESS;
2281 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "got failure");
2282 ret = GST_STATE_CHANGE_FAILURE;
2285 /* if nothing is pending anymore we can return SUCCESS */
2286 if (GST_STATE_PENDING (element) == GST_STATE_VOID_PENDING) {
2287 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "nothing pending");
2288 ret = GST_STATE_CHANGE_SUCCESS;
2294 *state = GST_STATE (element);
2296 *pending = GST_STATE_PENDING (element);
2298 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2299 "state current: %s, pending: %s, result: %s",
2300 gst_element_state_get_name (GST_STATE (element)),
2301 gst_element_state_get_name (GST_STATE_PENDING (element)),
2302 gst_element_state_change_return_get_name (ret));
2303 GST_OBJECT_UNLOCK (element);
2310 *state = GST_STATE_VOID_PENDING;
2312 *pending = GST_STATE_VOID_PENDING;
2314 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "interruped");
2316 GST_OBJECT_UNLOCK (element);
2318 return GST_STATE_CHANGE_FAILURE;
2323 * gst_element_get_state:
2324 * @element: a #GstElement to get the state of.
2325 * @state: (out) (allow-none): a pointer to #GstState to hold the state.
2327 * @pending: (out) (allow-none): a pointer to #GstState to hold the pending
2328 * state. Can be %NULL.
2329 * @timeout: a #GstClockTime to specify the timeout for an async
2330 * state change or %GST_CLOCK_TIME_NONE for infinite timeout.
2332 * Gets the state of the element.
2334 * For elements that performed an ASYNC state change, as reported by
2335 * gst_element_set_state(), this function will block up to the
2336 * specified timeout value for the state change to complete.
2337 * If the element completes the state change or goes into
2338 * an error, this function returns immediately with a return value of
2339 * %GST_STATE_CHANGE_SUCCESS or %GST_STATE_CHANGE_FAILURE respectively.
2341 * For elements that did not return %GST_STATE_CHANGE_ASYNC, this function
2342 * returns the current and pending state immediately.
2344 * This function returns %GST_STATE_CHANGE_NO_PREROLL if the element
2345 * successfully changed its state but is not able to provide data yet.
2346 * This mostly happens for live sources that only produce data in
2347 * %GST_STATE_PLAYING. While the state change return is equivalent to
2348 * %GST_STATE_CHANGE_SUCCESS, it is returned to the application to signal that
2349 * some sink elements might not be able to complete their state change because
2350 * an element is not producing data to complete the preroll. When setting the
2351 * element to playing, the preroll will complete and playback will start.
2353 * Returns: %GST_STATE_CHANGE_SUCCESS if the element has no more pending state
2354 * and the last state change succeeded, %GST_STATE_CHANGE_ASYNC if the
2355 * element is still performing a state change or
2356 * %GST_STATE_CHANGE_FAILURE if the last state change failed.
2360 GstStateChangeReturn
2361 gst_element_get_state (GstElement * element,
2362 GstState * state, GstState * pending, GstClockTime timeout)
2364 GstElementClass *oclass;
2365 GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE;
2367 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
2369 oclass = GST_ELEMENT_GET_CLASS (element);
2371 if (oclass->get_state)
2372 result = (oclass->get_state) (element, state, pending, timeout);
2378 * gst_element_abort_state:
2379 * @element: a #GstElement to abort the state of.
2381 * Abort the state change of the element. This function is used
2382 * by elements that do asynchronous state changes and find out
2383 * something is wrong.
2385 * This function should be called with the STATE_LOCK held.
2390 gst_element_abort_state (GstElement * element)
2394 #ifndef GST_DISABLE_GST_DEBUG
2398 g_return_if_fail (GST_IS_ELEMENT (element));
2400 GST_OBJECT_LOCK (element);
2401 pending = GST_STATE_PENDING (element);
2403 if (pending == GST_STATE_VOID_PENDING ||
2404 GST_STATE_RETURN (element) == GST_STATE_CHANGE_FAILURE)
2405 goto nothing_aborted;
2407 #ifndef GST_DISABLE_GST_DEBUG
2408 old_state = GST_STATE (element);
2410 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2411 "aborting state from %s to %s", gst_element_state_get_name (old_state),
2412 gst_element_state_get_name (pending));
2416 GST_STATE_RETURN (element) = GST_STATE_CHANGE_FAILURE;
2418 GST_STATE_BROADCAST (element);
2419 GST_OBJECT_UNLOCK (element);
2425 GST_OBJECT_UNLOCK (element);
2430 /* Not static because GstBin has manual state handling too */
2432 _priv_gst_element_state_changed (GstElement * element, GstState oldstate,
2433 GstState newstate, GstState pending)
2435 GstElementClass *klass = GST_ELEMENT_GET_CLASS (element);
2436 GstMessage *message;
2438 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2439 "notifying about state-changed %s to %s (%s pending)",
2440 gst_element_state_get_name (oldstate),
2441 gst_element_state_get_name (newstate),
2442 gst_element_state_get_name (pending));
2444 if (klass->state_changed)
2445 klass->state_changed (element, oldstate, newstate, pending);
2447 message = gst_message_new_state_changed (GST_OBJECT_CAST (element),
2448 oldstate, newstate, pending);
2449 gst_element_post_message (element, message);
2453 * gst_element_continue_state:
2454 * @element: a #GstElement to continue the state change of.
2455 * @ret: The previous state return value
2457 * Commit the state change of the element and proceed to the next
2458 * pending state if any. This function is used
2459 * by elements that do asynchronous state changes.
2460 * The core will normally call this method automatically when an
2461 * element returned %GST_STATE_CHANGE_SUCCESS from the state change function.
2463 * If after calling this method the element still has not reached
2464 * the pending state, the next state change is performed.
2466 * This method is used internally and should normally not be called by plugins
2469 * This function must be called with STATE_LOCK held.
2471 * Returns: The result of the commit state change.
2475 GstStateChangeReturn
2476 gst_element_continue_state (GstElement * element, GstStateChangeReturn ret)
2478 GstStateChangeReturn old_ret;
2479 GstState old_state, old_next;
2480 GstState current, next, pending;
2481 GstStateChange transition;
2483 GST_OBJECT_LOCK (element);
2484 old_ret = GST_STATE_RETURN (element);
2485 GST_STATE_RETURN (element) = ret;
2486 pending = GST_STATE_PENDING (element);
2488 /* check if there is something to commit */
2489 if (pending == GST_STATE_VOID_PENDING)
2490 goto nothing_pending;
2492 old_state = GST_STATE (element);
2493 /* this is the state we should go to next */
2494 old_next = GST_STATE_NEXT (element);
2495 /* update current state */
2496 current = GST_STATE (element) = old_next;
2498 /* see if we reached the final state */
2499 if (pending == current)
2502 next = GST_STATE_GET_NEXT (current, pending);
2503 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2505 GST_STATE_NEXT (element) = next;
2507 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2508 GST_OBJECT_UNLOCK (element);
2510 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2511 "committing state from %s to %s, pending %s, next %s",
2512 gst_element_state_get_name (old_state),
2513 gst_element_state_get_name (old_next),
2514 gst_element_state_get_name (pending), gst_element_state_get_name (next));
2516 _priv_gst_element_state_changed (element, old_state, old_next, pending);
2518 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2519 "continue state change %s to %s, final %s",
2520 gst_element_state_get_name (current),
2521 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2523 ret = gst_element_change_state (element, transition);
2529 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "nothing pending");
2530 GST_OBJECT_UNLOCK (element);
2535 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
2536 GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING;
2538 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2539 "completed state change to %s", gst_element_state_get_name (pending));
2540 GST_OBJECT_UNLOCK (element);
2542 /* don't post silly messages with the same state. This can happen
2543 * when an element state is changed to what it already was. For bins
2544 * this can be the result of a lost state, which we check with the
2545 * previous return value.
2546 * We do signal the cond though as a _get_state() might be blocking
2548 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC)
2549 _priv_gst_element_state_changed (element, old_state, old_next,
2550 GST_STATE_VOID_PENDING);
2552 GST_STATE_BROADCAST (element);
2559 * gst_element_lost_state:
2560 * @element: a #GstElement the state is lost of
2562 * Brings the element to the lost state. The current state of the
2563 * element is copied to the pending state so that any call to
2564 * gst_element_get_state() will return %GST_STATE_CHANGE_ASYNC.
2566 * An ASYNC_START message is posted. If the element was PLAYING, it will
2567 * go to PAUSED. The element will be restored to its PLAYING state by
2568 * the parent pipeline when it prerolls again.
2570 * This is mostly used for elements that lost their preroll buffer
2571 * in the %GST_STATE_PAUSED or %GST_STATE_PLAYING state after a flush,
2572 * they will go to their pending state again when a new preroll buffer is
2573 * queued. This function can only be called when the element is currently
2574 * not in error or an async state change.
2576 * This function is used internally and should normally not be called from
2577 * plugins or applications.
2580 gst_element_lost_state (GstElement * element)
2582 GstState old_state, new_state;
2583 GstMessage *message;
2585 g_return_if_fail (GST_IS_ELEMENT (element));
2587 GST_OBJECT_LOCK (element);
2588 if (GST_STATE_RETURN (element) == GST_STATE_CHANGE_FAILURE)
2591 if (GST_STATE_PENDING (element) != GST_STATE_VOID_PENDING)
2592 goto only_async_start;
2594 old_state = GST_STATE (element);
2596 /* when we were PLAYING, the new state is PAUSED. We will also not
2597 * automatically go to PLAYING but let the parent bin(s) set us to PLAYING
2598 * when we preroll. */
2599 if (old_state > GST_STATE_PAUSED)
2600 new_state = GST_STATE_PAUSED;
2602 new_state = old_state;
2604 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2605 "lost state of %s to %s", gst_element_state_get_name (old_state),
2606 gst_element_state_get_name (new_state));
2608 GST_STATE (element) = new_state;
2609 GST_STATE_NEXT (element) = new_state;
2610 GST_STATE_PENDING (element) = new_state;
2611 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2612 GST_OBJECT_UNLOCK (element);
2614 _priv_gst_element_state_changed (element, new_state, new_state, new_state);
2616 message = gst_message_new_async_start (GST_OBJECT_CAST (element));
2617 gst_element_post_message (element, message);
2623 GST_OBJECT_UNLOCK (element);
2628 GST_OBJECT_UNLOCK (element);
2630 message = gst_message_new_async_start (GST_OBJECT_CAST (element));
2631 gst_element_post_message (element, message);
2637 * gst_element_set_state:
2638 * @element: a #GstElement to change state of.
2639 * @state: the element's new #GstState.
2641 * Sets the state of the element. This function will try to set the
2642 * requested state by going through all the intermediary states and calling
2643 * the class's state change function for each.
2645 * This function can return #GST_STATE_CHANGE_ASYNC, in which case the
2646 * element will perform the remainder of the state change asynchronously in
2648 * An application can use gst_element_get_state() to wait for the completion
2649 * of the state change or it can wait for a %GST_MESSAGE_ASYNC_DONE or
2650 * %GST_MESSAGE_STATE_CHANGED on the bus.
2652 * State changes to %GST_STATE_READY or %GST_STATE_NULL never return
2653 * #GST_STATE_CHANGE_ASYNC.
2655 * Returns: Result of the state change using #GstStateChangeReturn.
2659 GstStateChangeReturn
2660 gst_element_set_state (GstElement * element, GstState state)
2662 GstElementClass *oclass;
2663 GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE;
2665 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
2667 oclass = GST_ELEMENT_GET_CLASS (element);
2669 if (oclass->set_state)
2670 result = (oclass->set_state) (element, state);
2676 * default set state function, calculates the next state based
2677 * on current state and calls the change_state function
2679 static GstStateChangeReturn
2680 gst_element_set_state_func (GstElement * element, GstState state)
2682 GstState current, next, old_pending;
2683 GstStateChangeReturn ret;
2684 GstStateChange transition;
2685 GstStateChangeReturn old_ret;
2687 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
2689 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "set_state to %s",
2690 gst_element_state_get_name (state));
2692 /* state lock is taken to protect the set_state() and get_state()
2693 * procedures, it does not lock any variables. */
2694 GST_STATE_LOCK (element);
2696 /* now calculate how to get to the new state */
2697 GST_OBJECT_LOCK (element);
2698 old_ret = GST_STATE_RETURN (element);
2699 /* previous state change returned an error, remove all pending
2700 * and next states */
2701 if (old_ret == GST_STATE_CHANGE_FAILURE) {
2702 GST_STATE_NEXT (element) = GST_STATE_VOID_PENDING;
2703 GST_STATE_PENDING (element) = GST_STATE_VOID_PENDING;
2704 GST_STATE_RETURN (element) = GST_STATE_CHANGE_SUCCESS;
2707 current = GST_STATE (element);
2708 next = GST_STATE_NEXT (element);
2709 old_pending = GST_STATE_PENDING (element);
2711 /* this is the (new) state we should go to. TARGET is the last state we set on
2713 if (state != GST_STATE_TARGET (element)) {
2714 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2715 "setting target state to %s", gst_element_state_get_name (state));
2716 GST_STATE_TARGET (element) = state;
2717 /* increment state cookie so that we can track each state change. We only do
2718 * this if this is actually a new state change. */
2719 element->state_cookie++;
2721 GST_STATE_PENDING (element) = state;
2723 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2724 "current %s, old_pending %s, next %s, old return %s",
2725 gst_element_state_get_name (current),
2726 gst_element_state_get_name (old_pending),
2727 gst_element_state_get_name (next),
2728 gst_element_state_change_return_get_name (old_ret));
2730 /* if the element was busy doing a state change, we just update the
2731 * target state, it'll get to it async then. */
2732 if (old_pending != GST_STATE_VOID_PENDING) {
2733 /* upwards state change will happen ASYNC */
2734 if (old_pending <= state)
2736 /* element is going to this state already */
2737 else if (next == state)
2739 /* element was performing an ASYNC upward state change and
2740 * we request to go downward again. Start from the next pending
2742 else if (next > state
2743 && GST_STATE_RETURN (element) == GST_STATE_CHANGE_ASYNC) {
2747 next = GST_STATE_GET_NEXT (current, state);
2748 /* now we store the next state */
2749 GST_STATE_NEXT (element) = next;
2750 /* mark busy, we need to check that there is actually a state change
2751 * to be done else we could accidentally override SUCCESS/NO_PREROLL and
2752 * the default element change_state function has no way to know what the
2753 * old value was... could consider this a FIXME...*/
2754 if (current != next)
2755 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2757 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2759 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2760 "%s: setting state from %s to %s",
2761 (next != state ? "intermediate" : "final"),
2762 gst_element_state_get_name (current), gst_element_state_get_name (next));
2764 /* now signal any waiters, they will error since the cookie was incremented */
2765 GST_STATE_BROADCAST (element);
2767 GST_OBJECT_UNLOCK (element);
2769 ret = gst_element_change_state (element, transition);
2771 GST_STATE_UNLOCK (element);
2773 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "returned %s",
2774 gst_element_state_change_return_get_name (ret));
2780 GST_STATE_RETURN (element) = GST_STATE_CHANGE_ASYNC;
2781 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2782 "element was busy with async state change");
2783 GST_OBJECT_UNLOCK (element);
2785 GST_STATE_UNLOCK (element);
2787 return GST_STATE_CHANGE_ASYNC;
2792 * gst_element_change_state:
2793 * @element: a #GstElement
2794 * @transition: the requested transition
2796 * Perform @transition on @element.
2798 * This function must be called with STATE_LOCK held and is mainly used
2801 * Returns: the #GstStateChangeReturn of the state transition.
2803 GstStateChangeReturn
2804 gst_element_change_state (GstElement * element, GstStateChange transition)
2806 GstElementClass *oclass;
2807 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
2809 oclass = GST_ELEMENT_GET_CLASS (element);
2811 GST_TRACER_ELEMENT_CHANGE_STATE_PRE (element, transition);
2813 /* call the state change function so it can set the state */
2814 if (oclass->change_state)
2815 ret = (oclass->change_state) (element, transition);
2817 ret = GST_STATE_CHANGE_FAILURE;
2819 GST_TRACER_ELEMENT_CHANGE_STATE_POST (element, transition, ret);
2822 case GST_STATE_CHANGE_FAILURE:
2823 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2824 "have FAILURE change_state return");
2825 /* state change failure */
2826 gst_element_abort_state (element);
2828 case GST_STATE_CHANGE_ASYNC:
2832 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2833 "element will change state ASYNC");
2835 target = GST_STATE_TARGET (element);
2837 if (target > GST_STATE_READY)
2840 /* else we just continue the state change downwards */
2841 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2842 "forcing commit state %s <= %s",
2843 gst_element_state_get_name (target),
2844 gst_element_state_get_name (GST_STATE_READY));
2846 ret = gst_element_continue_state (element, GST_STATE_CHANGE_SUCCESS);
2849 case GST_STATE_CHANGE_SUCCESS:
2850 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2851 "element changed state SUCCESS");
2852 /* we can commit the state now which will proceeed to
2854 ret = gst_element_continue_state (element, ret);
2856 case GST_STATE_CHANGE_NO_PREROLL:
2857 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2858 "element changed state NO_PREROLL");
2859 /* we can commit the state now which will proceeed to
2861 ret = gst_element_continue_state (element, ret);
2864 goto invalid_return;
2867 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "exit state change %d", ret);
2872 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element, "exit async state change %d",
2880 GST_OBJECT_LOCK (element);
2881 /* somebody added a GST_STATE_ and forgot to do stuff here ! */
2882 g_critical ("%s: unknown return value %d from a state change function",
2883 GST_ELEMENT_NAME (element), ret);
2885 /* we are in error now */
2886 ret = GST_STATE_CHANGE_FAILURE;
2887 GST_STATE_RETURN (element) = ret;
2888 GST_OBJECT_UNLOCK (element);
2894 /* gst_iterator_fold functions for pads_activate
2895 * Stop the iterator if activating one pad failed, but only if that pad
2896 * has not been removed from the element. */
2898 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2900 GstPad *pad = g_value_get_object (vpad);
2901 gboolean cont = TRUE;
2903 if (!gst_pad_set_active (pad, *active)) {
2904 if (GST_PAD_PARENT (pad) != NULL) {
2906 g_value_set_boolean (ret, FALSE);
2913 /* returns false on error or early cutout of the fold, true if all
2914 * pads in @iter were (de)activated successfully. */
2916 iterator_activate_fold_with_resync (GstIterator * iter,
2917 GstIteratorFoldFunction func, gpointer user_data)
2919 GstIteratorResult ires;
2922 /* no need to unset this later, it's just a boolean */
2923 g_value_init (&ret, G_TYPE_BOOLEAN);
2924 g_value_set_boolean (&ret, TRUE);
2927 ires = gst_iterator_fold (iter, func, &ret, user_data);
2929 case GST_ITERATOR_RESYNC:
2930 /* need to reset the result again */
2931 g_value_set_boolean (&ret, TRUE);
2932 gst_iterator_resync (iter);
2934 case GST_ITERATOR_DONE:
2935 /* all pads iterated, return collected value */
2938 /* iterator returned _ERROR or premature end with _OK,
2939 * mark an error and exit */
2940 g_value_set_boolean (&ret, FALSE);
2945 /* return collected value */
2946 return g_value_get_boolean (&ret);
2949 /* is called with STATE_LOCK
2951 * Pads are activated from source pads to sinkpads.
2954 gst_element_pads_activate (GstElement * element, gboolean active)
2959 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
2960 "%s pads", active ? "activate" : "deactivate");
2962 iter = gst_element_iterate_src_pads (element);
2964 iterator_activate_fold_with_resync (iter,
2965 (GstIteratorFoldFunction) activate_pads, &active);
2966 gst_iterator_free (iter);
2967 if (G_UNLIKELY (!res))
2970 iter = gst_element_iterate_sink_pads (element);
2972 iterator_activate_fold_with_resync (iter,
2973 (GstIteratorFoldFunction) activate_pads, &active);
2974 gst_iterator_free (iter);
2975 if (G_UNLIKELY (!res))
2978 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
2979 "pad %sactivation successful", active ? "" : "de");
2986 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
2987 "pad %sactivation failed", active ? "" : "de");
2992 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
2993 "sink pads_activate failed");
2998 /* is called with STATE_LOCK */
2999 static GstStateChangeReturn
3000 gst_element_change_state_func (GstElement * element, GstStateChange transition)
3002 GstState state, next;
3003 GstStateChangeReturn result = GST_STATE_CHANGE_SUCCESS;
3005 g_return_val_if_fail (GST_IS_ELEMENT (element), GST_STATE_CHANGE_FAILURE);
3007 state = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
3008 next = GST_STATE_TRANSITION_NEXT (transition);
3010 /* if the element already is in the given state, we just return success */
3011 if (next == GST_STATE_VOID_PENDING || state == next)
3014 GST_CAT_LOG_OBJECT (GST_CAT_STATES, element,
3015 "default handler tries setting state from %s to %s (%04x)",
3016 gst_element_state_get_name (state),
3017 gst_element_state_get_name (next), transition);
3019 switch (transition) {
3020 case GST_STATE_CHANGE_NULL_TO_READY:
3022 case GST_STATE_CHANGE_READY_TO_PAUSED:
3023 if (!gst_element_pads_activate (element, TRUE)) {
3024 result = GST_STATE_CHANGE_FAILURE;
3027 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
3029 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
3031 case GST_STATE_CHANGE_PAUSED_TO_READY:
3032 case GST_STATE_CHANGE_READY_TO_NULL:{
3035 /* deactivate pads in both cases, since they are activated on
3036 ready->paused but the element might not have made it to paused */
3037 if (!gst_element_pads_activate (element, FALSE)) {
3038 result = GST_STATE_CHANGE_FAILURE;
3041 /* Remove all non-persistent contexts */
3042 GST_OBJECT_LOCK (element);
3043 for (l = element->contexts; l;) {
3044 GstContext *context = l->data;
3046 if (!gst_context_is_persistent (context)) {
3049 gst_context_unref (context);
3051 element->contexts = g_list_delete_link (element->contexts, l);
3057 GST_OBJECT_UNLOCK (element);
3061 /* this will catch real but unhandled state changes;
3062 * can only be caused by:
3063 * - a new state was added
3064 * - somehow the element was asked to jump across an intermediate state
3066 g_warning ("Unhandled state change from %s to %s",
3067 gst_element_state_get_name (state),
3068 gst_element_state_get_name (next));
3075 GST_OBJECT_LOCK (element);
3076 result = GST_STATE_RETURN (element);
3077 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
3078 "element is already in the %s state",
3079 gst_element_state_get_name (state));
3080 GST_OBJECT_UNLOCK (element);
3087 * gst_element_get_factory:
3088 * @element: a #GstElement to request the element factory of.
3090 * Retrieves the factory that was used to create this element.
3092 * Returns: (transfer none): the #GstElementFactory used for creating this
3093 * element. no refcounting is needed.
3096 gst_element_get_factory (GstElement * element)
3098 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
3100 return GST_ELEMENT_GET_CLASS (element)->elementfactory;
3104 gst_element_dispose (GObject * object)
3106 GstElement *element = GST_ELEMENT_CAST (object);
3109 GstElementClass *oclass;
3112 oclass = GST_ELEMENT_GET_CLASS (element);
3114 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "%p dispose", element);
3116 if (GST_STATE (element) != GST_STATE_NULL)
3119 /* start by releasing all request pads, this might also remove some dynamic
3121 walk = element->pads;
3123 GstPad *pad = GST_PAD_CAST (walk->data);
3127 if (oclass->release_pad && GST_PAD_PAD_TEMPLATE (pad) &&
3128 GST_PAD_TEMPLATE_PRESENCE (GST_PAD_PAD_TEMPLATE (pad))
3129 == GST_PAD_REQUEST) {
3130 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
3131 "removing request pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3132 oclass->release_pad (element, pad);
3134 /* in case the release_pad function removed the next pad too */
3135 if (walk && g_list_position (element->pads, walk) == -1)
3136 walk = element->pads;
3139 /* remove the remaining pads */
3140 while (element->pads) {
3141 GstPad *pad = GST_PAD_CAST (element->pads->data);
3142 GST_CAT_DEBUG_OBJECT (GST_CAT_ELEMENT_PADS, element,
3143 "removing pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3144 if (!gst_element_remove_pad (element, pad)) {
3145 /* only happens when someone unparented our pad.. */
3146 g_critical ("failed to remove pad %s:%s", GST_DEBUG_PAD_NAME (pad));
3151 GST_OBJECT_LOCK (element);
3152 clock_p = &element->clock;
3153 bus_p = &element->bus;
3154 gst_object_replace ((GstObject **) clock_p, NULL);
3155 gst_object_replace ((GstObject **) bus_p, NULL);
3156 g_list_free_full (element->contexts, (GDestroyNotify) gst_context_unref);
3157 GST_OBJECT_UNLOCK (element);
3159 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "%p parent class dispose",
3162 G_OBJECT_CLASS (parent_class)->dispose (object);
3171 is_locked = GST_ELEMENT_IS_LOCKED_STATE (element);
3173 ("\nTrying to dispose element %s, but it is in %s%s instead of the NULL"
3175 "You need to explicitly set elements to the NULL state before\n"
3176 "dropping the final reference, to allow them to clean up.\n"
3177 "This problem may also be caused by a refcounting bug in the\n"
3178 "application or some element.\n",
3179 GST_OBJECT_NAME (element),
3180 gst_element_state_get_name (GST_STATE (element)),
3181 is_locked ? " (locked)" : "");
3187 gst_element_finalize (GObject * object)
3189 GstElement *element = GST_ELEMENT_CAST (object);
3191 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "%p finalize", element);
3193 g_cond_clear (&element->state_cond);
3194 g_rec_mutex_clear (&element->state_lock);
3196 GST_CAT_INFO_OBJECT (GST_CAT_REFCOUNTING, element, "%p finalize parent",
3199 G_OBJECT_CLASS (parent_class)->finalize (object);
3203 gst_element_set_bus_func (GstElement * element, GstBus * bus)
3207 g_return_if_fail (GST_IS_ELEMENT (element));
3209 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, element, "setting bus to %p", bus);
3211 GST_OBJECT_LOCK (element);
3212 bus_p = &GST_ELEMENT_BUS (element);
3213 gst_object_replace ((GstObject **) bus_p, GST_OBJECT_CAST (bus));
3214 GST_OBJECT_UNLOCK (element);
3218 * gst_element_set_bus:
3219 * @element: a #GstElement to set the bus of.
3220 * @bus: (transfer none): the #GstBus to set.
3222 * Sets the bus of the element. Increases the refcount on the bus.
3223 * For internal use only, unless you're testing elements.
3228 gst_element_set_bus (GstElement * element, GstBus * bus)
3230 GstElementClass *oclass;
3232 g_return_if_fail (GST_IS_ELEMENT (element));
3234 oclass = GST_ELEMENT_GET_CLASS (element);
3236 if (oclass->set_bus)
3237 oclass->set_bus (element, bus);
3241 * gst_element_get_bus:
3242 * @element: a #GstElement to get the bus of.
3244 * Returns the bus of the element. Note that only a #GstPipeline will provide a
3245 * bus for the application.
3247 * Returns: (transfer full): the element's #GstBus. unref after usage.
3252 gst_element_get_bus (GstElement * element)
3254 GstBus *result = NULL;
3256 g_return_val_if_fail (GST_IS_ELEMENT (element), result);
3258 GST_OBJECT_LOCK (element);
3259 if ((result = GST_ELEMENT_BUS (element)))
3260 gst_object_ref (result);
3261 GST_OBJECT_UNLOCK (element);
3263 GST_CAT_DEBUG_OBJECT (GST_CAT_BUS, element, "got bus %" GST_PTR_FORMAT,
3270 gst_element_set_context_default (GstElement * element, GstContext * context)
3272 const gchar *context_type;
3275 g_return_if_fail (GST_IS_CONTEXT (context));
3276 context_type = gst_context_get_context_type (context);
3277 g_return_if_fail (context_type != NULL);
3279 GST_OBJECT_LOCK (element);
3280 for (l = element->contexts; l; l = l->next) {
3281 GstContext *tmp = l->data;
3282 const gchar *tmp_type = gst_context_get_context_type (tmp);
3284 /* Always store newest context but never replace
3285 * a persistent one by a non-persistent one */
3286 if (g_strcmp0 (context_type, tmp_type) == 0 &&
3287 (gst_context_is_persistent (context) ||
3288 !gst_context_is_persistent (tmp))) {
3289 gst_context_replace ((GstContext **) & l->data, context);
3293 /* Not found? Add */
3296 g_list_prepend (element->contexts, gst_context_ref (context));
3298 GST_OBJECT_UNLOCK (element);
3302 * gst_element_set_context:
3303 * @element: a #GstElement to set the context of.
3304 * @context: (transfer none): the #GstContext to set.
3306 * Sets the context of the element. Increases the refcount of the context.
3311 gst_element_set_context (GstElement * element, GstContext * context)
3313 GstElementClass *oclass;
3315 g_return_if_fail (GST_IS_ELEMENT (element));
3316 g_return_if_fail (GST_IS_CONTEXT (context));
3318 oclass = GST_ELEMENT_GET_CLASS (element);
3320 GST_CAT_DEBUG_OBJECT (GST_CAT_CONTEXT, element,
3321 "set context %p %" GST_PTR_FORMAT, context,
3322 gst_context_get_structure (context));
3324 if (oclass->set_context)
3325 oclass->set_context (element, context);
3329 * gst_element_get_contexts:
3330 * @element: a #GstElement to set the context of.
3332 * Gets the contexts set on the element.
3336 * Returns: (element-type Gst.Context) (transfer full): List of #GstContext
3341 gst_element_get_contexts (GstElement * element)
3345 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
3347 GST_OBJECT_LOCK (element);
3348 ret = g_list_copy_deep (element->contexts, (GCopyFunc) gst_context_ref, NULL);
3349 GST_OBJECT_UNLOCK (element);
3355 _match_context_type (GstContext * c1, const gchar * context_type)
3357 const gchar *c1_type;
3359 c1_type = gst_context_get_context_type (c1);
3361 return g_strcmp0 (c1_type, context_type);
3365 * gst_element_get_context_unlocked:
3366 * @element: a #GstElement to get the context of.
3367 * @context_type: a name of a context to retrieve
3369 * Gets the context with @context_type set on the element or NULL.
3371 * Returns: (transfer full): A #GstContext or NULL
3376 gst_element_get_context_unlocked (GstElement * element,
3377 const gchar * context_type)
3379 GstContext *ret = NULL;
3382 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
3385 g_list_find_custom (element->contexts, context_type,
3386 (GCompareFunc) _match_context_type);
3387 if (node && node->data)
3388 ret = gst_context_ref (node->data);
3394 * gst_element_get_context:
3395 * @element: a #GstElement to get the context of.
3396 * @context_type: a name of a context to retrieve
3398 * Gets the context with @context_type set on the element or NULL.
3402 * Returns: (transfer full): A #GstContext or NULL
3407 gst_element_get_context (GstElement * element, const gchar * context_type)
3409 GstContext *ret = NULL;
3411 g_return_val_if_fail (GST_IS_ELEMENT (element), NULL);
3413 GST_OBJECT_LOCK (element);
3414 ret = gst_element_get_context_unlocked (element, context_type);
3415 GST_OBJECT_UNLOCK (element);
3421 gst_element_property_post_notify_msg (GstElement * element, GObject * obj,
3422 GParamSpec * pspec, gboolean include_value)
3424 GValue val = G_VALUE_INIT;
3427 GST_LOG_OBJECT (element, "property '%s' of object %" GST_PTR_FORMAT " has "
3428 "changed, posting message with%s value", pspec->name, obj,
3429 include_value ? "" : "out");
3431 if (include_value && (pspec->flags & G_PARAM_READABLE) != 0) {
3432 g_value_init (&val, pspec->value_type);
3433 g_object_get_property (obj, pspec->name, &val);
3438 gst_element_post_message (element,
3439 gst_message_new_property_notify (GST_OBJECT_CAST (obj), pspec->name, v));
3443 gst_element_property_deep_notify_cb (GstElement * element, GObject * prop_obj,
3444 GParamSpec * pspec, gpointer user_data)
3446 gboolean include_value = GPOINTER_TO_INT (user_data);
3448 gst_element_property_post_notify_msg (element, prop_obj, pspec,
3453 gst_element_property_notify_cb (GObject * obj, GParamSpec * pspec,
3456 gboolean include_value = GPOINTER_TO_INT (user_data);
3458 gst_element_property_post_notify_msg (GST_ELEMENT_CAST (obj), obj, pspec,
3463 * gst_element_add_property_notify_watch:
3464 * @element: a #GstElement to watch for property changes
3465 * @property_name: (allow-none): name of property to watch for changes, or
3466 * NULL to watch all properties
3467 * @include_value: whether to include the new property value in the message
3469 * Returns: a watch id, which can be used in connection with
3470 * gst_element_remove_property_notify_watch() to remove the watch again.
3475 gst_element_add_property_notify_watch (GstElement * element,
3476 const gchar * property_name, gboolean include_value)
3482 g_return_val_if_fail (GST_IS_ELEMENT (element), 0);
3484 sep = (property_name != NULL) ? "::" : NULL;
3485 signal_name = g_strconcat ("notify", sep, property_name, NULL);
3486 id = g_signal_connect (element, signal_name,
3487 G_CALLBACK (gst_element_property_notify_cb),
3488 GINT_TO_POINTER (include_value));
3489 g_free (signal_name);
3495 * gst_element_add_property_deep_notify_watch:
3496 * @element: a #GstElement to watch (recursively) for property changes
3497 * @property_name: (allow-none): name of property to watch for changes, or
3498 * NULL to watch all properties
3499 * @include_value: whether to include the new property value in the message
3501 * Returns: a watch id, which can be used in connection with
3502 * gst_element_remove_property_notify_watch() to remove the watch again.
3507 gst_element_add_property_deep_notify_watch (GstElement * element,
3508 const gchar * property_name, gboolean include_value)
3514 g_return_val_if_fail (GST_IS_ELEMENT (element), 0);
3516 sep = (property_name != NULL) ? "::" : NULL;
3517 signal_name = g_strconcat ("deep-notify", sep, property_name, NULL);
3518 id = g_signal_connect (element, signal_name,
3519 G_CALLBACK (gst_element_property_deep_notify_cb),
3520 GINT_TO_POINTER (include_value));
3521 g_free (signal_name);
3527 * gst_element_remove_property_notify_watch:
3528 * @element: a #GstElement being watched for property changes
3529 * @watch_id: watch id to remove
3534 gst_element_remove_property_notify_watch (GstElement * element, gulong watch_id)
3536 g_signal_handler_disconnect (element, watch_id);
3541 GstElement *element;
3542 GstElementCallAsyncFunc func;
3544 GDestroyNotify destroy_notify;
3545 } GstElementCallAsyncData;
3548 gst_element_call_async_func (gpointer data, gpointer user_data)
3550 GstElementCallAsyncData *async_data = data;
3552 async_data->func (async_data->element, async_data->user_data);
3553 if (async_data->destroy_notify)
3554 async_data->destroy_notify (async_data->user_data);
3555 gst_object_unref (async_data->element);
3556 g_free (async_data);
3560 * gst_element_call_async:
3561 * @element: a #GstElement
3562 * @func: Function to call asynchronously from another thread
3563 * @user_data: Data to pass to @func
3564 * @destroy_notify: GDestroyNotify for @user_data
3566 * Calls @func from another thread and passes @user_data to it. This is to be
3567 * used for cases when a state change has to be performed from a streaming
3568 * thread, directly via gst_element_set_state() or indirectly e.g. via SEEK
3571 * Calling those functions directly from the streaming thread will cause
3572 * deadlocks in many situations, as they might involve waiting for the
3573 * streaming thread to shut down from this very streaming thread.
3580 gst_element_call_async (GstElement * element, GstElementCallAsyncFunc func,
3581 gpointer user_data, GDestroyNotify destroy_notify)
3583 GstElementCallAsyncData *async_data;
3585 g_return_if_fail (GST_IS_ELEMENT (element));
3587 async_data = g_new0 (GstElementCallAsyncData, 1);
3588 async_data->element = gst_object_ref (element);
3589 async_data->func = func;
3590 async_data->user_data = user_data;
3591 async_data->destroy_notify = destroy_notify;
3593 g_thread_pool_push (gst_element_pool, async_data, NULL);
3597 _priv_gst_element_cleanup (void)
3599 if (gst_element_pool) {
3600 g_thread_pool_free (gst_element_pool, FALSE, TRUE);
3601 gst_element_setup_thread_pool ();
3606 gst_make_element_message_details (const char *name, ...)
3608 GstStructure *structure;
3614 va_start (varargs, name);
3615 structure = gst_structure_new_valist ("details", name, varargs);