3 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
4 * 2004 Wim Taymans <wim.taymans@gmail.com>
6 * gstbin.c: GstBin container object and support code
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
29 * @short_description: Base class and element that can contain other elements
31 * #GstBin is an element that can contain other #GstElement, allowing them to be
33 * Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
34 * This makes the bin look like any other elements and enables creation of
35 * higher-level abstraction elements.
37 * A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
38 * want to create a toplevel bin because a normal bin doesn't have a bus or
39 * handle clock distribution of its own.
41 * After the bin has been created you will typically add elements to it with
42 * gst_bin_add(). You can remove elements with gst_bin_remove().
44 * An element can be retrieved from a bin with gst_bin_get_by_name(), using the
45 * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
46 * purposes and will query the parent bins when the element is not found in the
49 * An iterator of elements in a bin can be retrieved with
50 * gst_bin_iterate_elements(). Various other iterators exist to retrieve the
53 * gst_object_unref() is used to drop your reference to the bin.
55 * The #GstBin::element-added signal is fired whenever a new element is added to
56 * the bin. Likewise the #GstBin::element-removed signal is fired whenever an
57 * element is removed from the bin.
61 * A #GstBin internally intercepts every #GstMessage posted by its children and
62 * implements the following default behaviour for each of them:
64 * * GST_MESSAGE_EOS: This message is only posted by sinks in the PLAYING
65 * state. If all sinks posted the EOS message, this bin will post and EOS
68 * * GST_MESSAGE_SEGMENT_START: Just collected and never forwarded upwards.
69 * The messages are used to decide when all elements have completed playback
72 * * GST_MESSAGE_SEGMENT_DONE: Is posted by #GstBin when all elements that posted
73 * a SEGMENT_START have posted a SEGMENT_DONE.
75 * * GST_MESSAGE_DURATION_CHANGED: Is posted by an element that detected a change
76 * in the stream duration. The default bin behaviour is to clear any
77 * cached duration values so that the next duration query will perform
78 * a full duration recalculation. The duration change is posted to the
79 * application so that it can refetch the new duration with a duration
80 * query. Note that these messages can be posted before the bin is
81 * prerolled, in which case the duration query might fail.
83 * * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
84 * can no longer provide a clock. The default bin behaviour is to
85 * check if the lost clock was the one provided by the bin. If so and
86 * the bin is currently in the PLAYING state, the message is forwarded to
88 * This message is also generated when a clock provider is removed from
89 * the bin. If this message is received by the application, it should
90 * PAUSE the pipeline and set it back to PLAYING to force a new clock
93 * * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
94 * can provide a clock. This mostly happens when a new clock
95 * provider is added to the bin. The default behaviour of the bin is to
96 * mark the currently selected clock as dirty, which will perform a clock
97 * recalculation the next time the bin is asked to provide a clock.
98 * This message is never sent tot the application but is forwarded to
99 * the parent of the bin.
101 * * OTHERS: posted upwards.
103 * A #GstBin implements the following default behaviour for answering to a
106 * * GST_QUERY_DURATION:If the query has been asked before with the same format
107 * and the bin is a toplevel bin (ie. has no parent),
108 * use the cached previous value. If no previous value was cached, the
109 * query is sent to all sink elements in the bin and the MAXIMUM of all
110 * values is returned. If the bin is a toplevel bin the value is cached.
111 * If no sinks are available in the bin, the query fails.
113 * * GST_QUERY_POSITION:The query is sent to all sink elements in the bin and the
114 * MAXIMUM of all values is returned. If no sinks are available in the bin,
117 * * OTHERS:the query is forwarded to all sink elements, the result
118 * of the first sink that answers the query successfully is returned. If no
119 * sink is in the bin, the query fails.
121 * A #GstBin will by default forward any event sent to it to all sink
122 * (#GST_EVENT_TYPE_DOWNSTREAM) or source (#GST_EVENT_TYPE_UPSTREAM) elements
123 * depending on the event type.
124 * If all the elements return %TRUE, the bin will also return %TRUE, else %FALSE
125 * is returned. If no elements of the required type are in the bin, the event
126 * handler will return %TRUE.
130 #include "gst_private.h"
132 #include "gstevent.h"
135 #include "gsterror.h"
137 #include "gstutils.h"
138 #include "gstchildproxy.h"
140 GST_DEBUG_CATEGORY_STATIC (bin_debug);
141 #define GST_CAT_DEFAULT bin_debug
143 /* a bin is toplevel if it has no parent or when it is configured to behave like
145 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
147 struct _GstBinPrivate
149 gboolean asynchandling;
150 /* if we get an ASYNC_DONE message from ourselves, this means that the
151 * subclass will simulate ASYNC behaviour without having ASYNC children. When
152 * such an ASYNC_DONE message is posted while we are doing a state change, we
153 * have to process the message after finishing the state change even when no
154 * child returned GST_STATE_CHANGE_ASYNC. */
155 gboolean pending_async_done;
157 guint32 structure_cookie;
164 /* forward messages from our children */
165 gboolean message_forward;
168 gboolean posted_playing;
169 GstElementFlags suppressed_flags;
178 static void gst_bin_dispose (GObject * object);
180 static void gst_bin_set_property (GObject * object, guint prop_id,
181 const GValue * value, GParamSpec * pspec);
182 static void gst_bin_get_property (GObject * object, guint prop_id,
183 GValue * value, GParamSpec * pspec);
185 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
186 GstStateChange transition);
187 static gboolean gst_bin_post_message (GstElement * element, GstMessage * msg);
188 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
189 GstState * state, GstState * pending, GstClockTime timeout);
190 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
191 gboolean flag_pending, GstClockTime running_time);
192 static void bin_handle_async_start (GstBin * bin);
193 static void bin_push_state_continue (GstBin * bin, BinContinueData * data);
194 static void bin_do_eos (GstBin * bin);
196 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
197 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
198 static void gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
199 GstElement * element);
200 static void gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
201 GstElement * element);
202 static void gst_bin_update_context (GstBin * bin, GstContext * context);
203 static void gst_bin_update_context_unlocked (GstBin * bin,
204 GstContext * context);
207 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
208 static GstIndex *gst_bin_get_index_func (GstElement * element);
211 static GstClock *gst_bin_provide_clock_func (GstElement * element);
212 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
214 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
215 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
216 static GstBusSyncReply bin_bus_handler (GstBus * bus,
217 GstMessage * message, GstBin * bin);
218 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
219 static void gst_bin_set_context (GstElement * element, GstContext * context);
221 static gboolean gst_bin_do_latency_func (GstBin * bin);
223 static void bin_remove_messages (GstBin * bin, GstObject * src,
224 GstMessageType types);
225 static void gst_bin_continue_func (GstBin * bin, BinContinueData * data);
226 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
227 static gint bin_element_is_src (GstElement * child, GstBin * bin);
229 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
231 /* Bin signals and properties */
238 DEEP_ELEMENT_REMOVED,
242 #define DEFAULT_ASYNC_HANDLING FALSE
243 #define DEFAULT_MESSAGE_FORWARD FALSE
249 PROP_MESSAGE_FORWARD,
253 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
255 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
259 static const GInterfaceInfo iface_info = { \
260 gst_bin_child_proxy_init, \
264 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
266 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
267 "debugging info for the 'bin' container element"); \
271 #define gst_bin_parent_class parent_class
272 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT,
273 G_ADD_PRIVATE (GstBin)
277 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
283 bin = GST_BIN_CAST (child_proxy);
285 GST_OBJECT_LOCK (bin);
286 if ((res = g_list_nth_data (bin->children, index)))
287 gst_object_ref (res);
288 GST_OBJECT_UNLOCK (bin);
290 return (GObject *) res;
294 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
299 bin = GST_BIN_CAST (child_proxy);
301 GST_OBJECT_LOCK (bin);
302 num = bin->numchildren;
303 GST_OBJECT_UNLOCK (bin);
309 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
311 GstChildProxyInterface *iface = g_iface;
313 iface->get_children_count = gst_bin_child_proxy_get_children_count;
314 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
318 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
319 GValue * return_accu, const GValue * handler_return, gpointer dummy)
323 myboolean = g_value_get_boolean (handler_return);
324 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
325 g_value_set_boolean (return_accu, myboolean);
327 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
334 gst_bin_class_init (GstBinClass * klass)
336 GObjectClass *gobject_class;
337 GstElementClass *gstelement_class;
339 gobject_class = (GObjectClass *) klass;
340 gstelement_class = (GstElementClass *) klass;
342 gobject_class->set_property = gst_bin_set_property;
343 gobject_class->get_property = gst_bin_get_property;
346 * GstBin:async-handling:
348 * If set to %TRUE, the bin will handle asynchronous state changes.
349 * This should be used only if the bin subclass is modifying the state
350 * of its children on its own.
352 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
353 g_param_spec_boolean ("async-handling", "Async Handling",
354 "The bin will handle Asynchronous state changes",
355 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
358 * GstBin::element-added:
360 * @element: the #GstElement that was added to the bin
362 * Will be emitted after the element was added to the bin.
364 gst_bin_signals[ELEMENT_ADDED] =
365 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
366 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
367 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
369 * GstBin::element-removed:
371 * @element: the #GstElement that was removed from the bin
373 * Will be emitted after the element was removed from the bin.
375 gst_bin_signals[ELEMENT_REMOVED] =
376 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
377 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
378 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
380 * GstBin::deep-element-added:
382 * @sub_bin: the #GstBin the element was added to
383 * @element: the #GstElement that was added to @sub_bin
385 * Will be emitted after the element was added to sub_bin.
389 gst_bin_signals[DEEP_ELEMENT_ADDED] =
390 g_signal_new ("deep-element-added", G_TYPE_FROM_CLASS (klass),
391 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_added),
392 NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_BIN,
395 * GstBin::deep-element-removed:
397 * @sub_bin: the #GstBin the element was removed from
398 * @element: the #GstElement that was removed from @sub_bin
400 * Will be emitted after the element was removed from sub_bin.
404 gst_bin_signals[DEEP_ELEMENT_REMOVED] =
405 g_signal_new ("deep-element-removed", G_TYPE_FROM_CLASS (klass),
406 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_removed),
407 NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_BIN,
410 * GstBin::do-latency:
413 * Will be emitted when the bin needs to perform latency calculations. This
414 * signal is only emitted for toplevel bins or when async-handling is
417 * Only one signal handler is invoked. If no signals are connected, the
418 * default handler is invoked, which will query and distribute the lowest
419 * possible latency to all sinks.
421 * Connect to this signal if the default latency calculations are not
422 * sufficient, like when you need different latencies for different sinks in
425 gst_bin_signals[DO_LATENCY] =
426 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
427 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
428 _gst_boolean_accumulator, NULL, g_cclosure_marshal_generic,
429 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
432 * GstBin:message-forward:
434 * Forward all children messages, even those that would normally be filtered by
435 * the bin. This can be interesting when one wants to be notified of the EOS
436 * state of individual elements, for example.
438 * The messages are converted to an ELEMENT message with the bin as the
439 * source. The structure of the message is named 'GstBinForwarded' and contains
440 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
443 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
444 g_param_spec_boolean ("message-forward", "Message Forward",
445 "Forwards all children messages",
446 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
448 gobject_class->dispose = gst_bin_dispose;
450 gst_element_class_set_static_metadata (gstelement_class, "Generic bin",
452 "Simple container object",
453 "Erik Walthinsen <omega@cse.ogi.edu>,"
454 "Wim Taymans <wim.taymans@gmail.com>");
456 gstelement_class->change_state =
457 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
458 gstelement_class->post_message = GST_DEBUG_FUNCPTR (gst_bin_post_message);
459 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
461 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
462 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
464 gstelement_class->provide_clock =
465 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
466 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
468 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
469 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
470 gstelement_class->set_context = GST_DEBUG_FUNCPTR (gst_bin_set_context);
472 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
473 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
474 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
476 klass->deep_element_added = gst_bin_deep_element_added_func;
477 klass->deep_element_removed = gst_bin_deep_element_removed_func;
479 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
483 gst_bin_init (GstBin * bin)
487 bin->numchildren = 0;
488 bin->children = NULL;
489 bin->children_cookie = 0;
490 bin->messages = NULL;
491 bin->provided_clock = NULL;
492 bin->clock_dirty = FALSE;
494 /* Set up a bus for listening to child elements */
495 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
496 gst_object_ref_sink (bus);
497 bin->child_bus = bus;
498 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
500 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin,
503 bin->priv = gst_bin_get_instance_private (bin);
504 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
505 bin->priv->structure_cookie = 0;
506 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
510 gst_bin_dispose (GObject * object)
512 GstBin *bin = GST_BIN_CAST (object);
513 GstBus **child_bus_p = &bin->child_bus;
514 GstClock **provided_clock_p = &bin->provided_clock;
515 GstElement **clock_provider_p = &bin->clock_provider;
517 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "%p dispose", object);
519 GST_OBJECT_LOCK (object);
520 gst_object_replace ((GstObject **) child_bus_p, NULL);
521 gst_object_replace ((GstObject **) provided_clock_p, NULL);
522 gst_object_replace ((GstObject **) clock_provider_p, NULL);
523 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
524 GST_OBJECT_UNLOCK (object);
526 while (bin->children) {
527 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
529 if (G_UNLIKELY (bin->children != NULL)) {
530 g_critical ("could not remove elements from bin '%s'",
531 GST_STR_NULL (GST_OBJECT_NAME (object)));
534 G_OBJECT_CLASS (parent_class)->dispose (object);
539 * @name: (allow-none): the name of the new bin
541 * Creates a new bin with the given name.
543 * Returns: (transfer floating): a new #GstBin
546 gst_bin_new (const gchar * name)
548 return gst_element_factory_make ("bin", name);
552 gst_bin_set_property (GObject * object, guint prop_id,
553 const GValue * value, GParamSpec * pspec)
557 gstbin = GST_BIN_CAST (object);
560 case PROP_ASYNC_HANDLING:
561 GST_OBJECT_LOCK (gstbin);
562 gstbin->priv->asynchandling = g_value_get_boolean (value);
563 GST_OBJECT_UNLOCK (gstbin);
565 case PROP_MESSAGE_FORWARD:
566 GST_OBJECT_LOCK (gstbin);
567 gstbin->priv->message_forward = g_value_get_boolean (value);
568 GST_OBJECT_UNLOCK (gstbin);
571 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
577 gst_bin_get_property (GObject * object, guint prop_id,
578 GValue * value, GParamSpec * pspec)
582 gstbin = GST_BIN_CAST (object);
585 case PROP_ASYNC_HANDLING:
586 GST_OBJECT_LOCK (gstbin);
587 g_value_set_boolean (value, gstbin->priv->asynchandling);
588 GST_OBJECT_UNLOCK (gstbin);
590 case PROP_MESSAGE_FORWARD:
591 GST_OBJECT_LOCK (gstbin);
592 g_value_set_boolean (value, gstbin->priv->message_forward);
593 GST_OBJECT_UNLOCK (gstbin);
596 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
602 /* return the cached index */
604 gst_bin_get_index_func (GstElement * element)
609 bin = GST_BIN_CAST (element);
611 GST_OBJECT_LOCK (bin);
612 if ((result = bin->priv->index))
613 gst_object_ref (result);
614 GST_OBJECT_UNLOCK (bin);
619 /* set the index on all elements in this bin
624 gst_bin_set_index_func (GstElement * element, GstIndex * index)
630 GValue data = { 0, };
632 bin = GST_BIN_CAST (element);
634 GST_OBJECT_LOCK (bin);
635 old = bin->priv->index;
636 if (G_UNLIKELY (old == index))
639 gst_object_ref (index);
640 bin->priv->index = index;
641 GST_OBJECT_UNLOCK (bin);
644 gst_object_unref (old);
646 it = gst_bin_iterate_elements (bin);
648 /* set the index on all elements in the bin */
651 switch (gst_iterator_next (it, &data)) {
652 case GST_ITERATOR_OK:
654 GstElement *child = g_value_get_object (&data);
656 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
657 GST_ELEMENT_NAME (child));
658 gst_element_set_index (child, index);
660 g_value_reset (&data);
663 case GST_ITERATOR_RESYNC:
664 GST_DEBUG_OBJECT (bin, "iterator doing resync");
665 gst_iterator_resync (it);
668 case GST_ITERATOR_DONE:
669 GST_DEBUG_OBJECT (bin, "iterator done");
674 g_value_unset (&data);
675 gst_iterator_free (it);
680 GST_DEBUG_OBJECT (bin, "index was already set");
681 GST_OBJECT_UNLOCK (bin);
687 /* set the clock on all elements in this bin
692 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
698 GValue data = { 0, };
700 bin = GST_BIN_CAST (element);
702 it = gst_bin_iterate_elements (bin);
706 switch (gst_iterator_next (it, &data)) {
707 case GST_ITERATOR_OK:
709 GstElement *child = g_value_get_object (&data);
711 res &= gst_element_set_clock (child, clock);
713 g_value_reset (&data);
716 case GST_ITERATOR_RESYNC:
717 GST_DEBUG_OBJECT (bin, "iterator doing resync");
718 gst_iterator_resync (it);
722 case GST_ITERATOR_DONE:
723 GST_DEBUG_OBJECT (bin, "iterator done");
728 g_value_unset (&data);
729 gst_iterator_free (it);
732 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
737 /* get the clock for this bin by asking all of the children in this bin
739 * The ref of the returned clock in increased so unref after usage.
741 * We loop the elements in state order and pick the last clock we can
742 * get. This makes sure we get a clock from the source.
747 gst_bin_provide_clock_func (GstElement * element)
749 GstClock *result = NULL;
750 GstElement *provider = NULL;
755 GstClock **provided_clock_p;
756 GstElement **clock_provider_p;
758 bin = GST_BIN_CAST (element);
760 GST_OBJECT_LOCK (bin);
761 if (!bin->clock_dirty)
764 GST_DEBUG_OBJECT (bin, "finding new clock");
766 it = gst_bin_sort_iterator_new (bin);
767 GST_OBJECT_UNLOCK (bin);
771 switch (gst_iterator_next (it, &val)) {
772 case GST_ITERATOR_OK:
774 GstElement *child = g_value_get_object (&val);
777 clock = gst_element_provide_clock (child);
779 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
780 clock, GST_ELEMENT_NAME (child));
782 gst_object_unref (result);
783 gst_object_unref (provider);
786 provider = gst_object_ref (child);
789 g_value_reset (&val);
792 case GST_ITERATOR_RESYNC:
793 gst_iterator_resync (it);
796 case GST_ITERATOR_DONE:
801 g_value_unset (&val);
802 gst_iterator_free (it);
804 GST_OBJECT_LOCK (bin);
805 if (!bin->clock_dirty) {
807 gst_object_unref (provider);
809 gst_object_unref (result);
815 provided_clock_p = &bin->provided_clock;
816 clock_provider_p = &bin->clock_provider;
817 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
818 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
819 bin->clock_dirty = FALSE;
820 GST_DEBUG_OBJECT (bin,
821 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
823 /* Provider is not being returned to caller, just the result */
825 gst_object_unref (provider);
826 GST_OBJECT_UNLOCK (bin);
832 if ((result = bin->provided_clock))
833 gst_object_ref (result);
834 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
835 GST_OBJECT_UNLOCK (bin);
842 * functions for manipulating cached messages
847 GstMessageType types;
850 /* check if a message is of given src and type */
852 message_check (GstMessage * message, MessageFind * target)
857 eq &= GST_MESSAGE_SRC (message) == target->src;
859 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
860 GST_LOG ("looking at message %p: %d", message, eq);
866 find_message (GstBin * bin, GstObject * src, GstMessageType types)
874 result = g_list_find_custom (bin->messages, &find,
875 (GCompareFunc) message_check);
878 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
879 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
882 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
883 #ifndef GST_DISABLE_GST_DEBUG
887 for (i = 0; i < 32; i++)
888 if (types & (1U << i))
889 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1U << i));
897 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
900 * A message that is cached and has the same SRC and type is replaced
901 * by the given message.
904 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
910 if ((src = GST_MESSAGE_SRC (message))) {
911 /* first find the previous message posted by this element */
912 if ((previous = find_message (bin, src, types))) {
913 GstMessage *previous_msg;
915 /* if we found a previous message, replace it */
916 previous_msg = previous->data;
917 previous->data = message;
919 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
920 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
921 GST_MESSAGE_TYPE_NAME (message));
923 gst_message_unref (previous_msg);
925 /* keep new message */
926 bin->messages = g_list_prepend (bin->messages, message);
928 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
929 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
932 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
933 GST_MESSAGE_TYPE_NAME (message));
935 gst_message_unref (message);
940 /* with LOCK. Remove all messages of given types */
942 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
950 for (walk = bin->messages; walk; walk = next) {
951 GstMessage *message = (GstMessage *) walk->data;
953 next = g_list_next (walk);
955 if (message_check (message, &find) == 0) {
956 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
957 "deleting message %p of type %s (types 0x%08x)", message,
958 GST_MESSAGE_TYPE_NAME (message), types);
959 bin->messages = g_list_delete_link (bin->messages, walk);
960 gst_message_unref (message);
962 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
963 "not deleting message %p of type 0x%08x", message,
964 GST_MESSAGE_TYPE (message));
970 /* Check if the bin is EOS. We do this by scanning all sinks and
971 * checking if they posted an EOS message.
973 * call with bin LOCK */
975 is_eos (GstBin * bin, guint32 * seqnum)
982 for (walk = bin->children; walk; walk = g_list_next (walk)) {
985 element = GST_ELEMENT_CAST (walk->data);
986 if (bin_element_is_sink (element, bin) == 0) {
987 /* check if element posted EOS */
989 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
990 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
991 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
994 GST_DEBUG ("sink '%s' did not post EOS yet",
995 GST_ELEMENT_NAME (element));
1001 /* FIXME: Some tests (e.g. elements/capsfilter) use
1002 * pipelines with a dangling sinkpad but no sink element.
1003 * These tests assume that no EOS message is ever
1004 * posted on the bus so let's keep that behaviour.
1005 * In valid pipelines this doesn't make a difference.
1007 return result && n_eos > 0;
1011 /* Check if the bin is STREAM_START. We do this by scanning all sinks and
1012 * checking if they posted an STREAM_START message.
1014 * call with bin LOCK */
1016 is_stream_start (GstBin * bin, guint32 * seqnum, gboolean * have_group_id,
1022 gboolean first = TRUE, same_group_id = TRUE;
1024 *have_group_id = TRUE;
1027 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1028 GstElement *element;
1030 element = GST_ELEMENT_CAST (walk->data);
1031 if (bin_element_is_sink (element, bin) == 0) {
1032 /* check if element posted STREAM_START */
1034 find_message (bin, GST_OBJECT_CAST (element),
1035 GST_MESSAGE_STREAM_START))) {
1036 GST_DEBUG ("sink '%s' posted STREAM_START", GST_ELEMENT_NAME (element));
1037 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1038 if (gst_message_parse_group_id (GST_MESSAGE_CAST (msgs->data),
1042 *group_id = tmp_group_id;
1044 if (tmp_group_id != *group_id)
1045 same_group_id = FALSE;
1048 *have_group_id = FALSE;
1051 GST_DEBUG ("sink '%s' did not post STREAM_START yet",
1052 GST_ELEMENT_NAME (element));
1059 /* If all have a group_id we only consider this stream started
1060 * if all group ids were the same and all sinks posted a stream-start
1063 return same_group_id && result;
1064 /* otherwise consider this stream started after all sinks
1065 * have reported stream-start for backward compatibility.
1066 * FIXME 2.0: This should go away! */
1071 unlink_pads (const GValue * item, gpointer user_data)
1076 pad = g_value_get_object (item);
1078 if ((peer = gst_pad_get_peer (pad))) {
1079 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1080 gst_pad_unlink (pad, peer);
1082 gst_pad_unlink (peer, pad);
1083 gst_object_unref (peer);
1088 bin_deep_iterator_foreach (const GValue * item, gpointer user_data)
1090 GQueue *queue = user_data;
1092 g_queue_push_tail (queue, g_value_dup_object (item));
1096 gst_bin_do_deep_add_remove (GstBin * bin, gint sig_id, const gchar * sig_name,
1097 GstElement * element)
1099 g_signal_emit (bin, sig_id, 0, bin, element);
1101 /* When removing a bin, emit deep-element-* for everything in the bin too */
1102 if (GST_IS_BIN (element)) {
1104 GstIteratorResult ires;
1105 GQueue elements = G_QUEUE_INIT;
1107 GST_LOG_OBJECT (bin, "Recursing into bin %" GST_PTR_FORMAT " for %s",
1109 it = gst_bin_iterate_recurse (GST_BIN_CAST (element));
1111 ires = gst_iterator_foreach (it, bin_deep_iterator_foreach, &elements);
1112 if (ires != GST_ITERATOR_DONE) {
1113 g_queue_foreach (&elements, (GFunc) g_object_unref, NULL);
1114 g_queue_clear (&elements);
1116 if (ires == GST_ITERATOR_RESYNC)
1117 gst_iterator_resync (it);
1118 } while (ires == GST_ITERATOR_RESYNC);
1119 if (ires != GST_ITERATOR_ERROR) {
1122 while ((e = g_queue_pop_head (&elements))) {
1123 GstObject *parent = gst_object_get_parent (GST_OBJECT_CAST (e));
1125 /* an element could have removed some of its internal elements
1126 * meanwhile, so protect against that */
1128 GST_LOG_OBJECT (bin, "calling %s for element %" GST_PTR_FORMAT
1129 " in bin %" GST_PTR_FORMAT, sig_name, e, parent);
1130 g_signal_emit (bin, sig_id, 0, parent, e);
1131 gst_object_unref (parent);
1136 gst_iterator_free (it);
1140 /* vmethod that adds an element to a bin
1145 gst_bin_add_func (GstBin * bin, GstElement * element)
1149 gboolean is_sink, is_source, provides_clock, requires_clock;
1150 GstMessage *clock_message = NULL, *async_message = NULL;
1151 GstStateChangeReturn ret;
1152 GList *l, *elem_contexts, *need_context_messages;
1154 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1156 /* we obviously can't add ourself to ourself */
1157 if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
1160 /* get the element name to make sure it is unique in this bin. */
1161 GST_OBJECT_LOCK (element);
1162 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1163 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1164 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1166 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1168 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1169 GST_OBJECT_UNLOCK (element);
1171 GST_OBJECT_LOCK (bin);
1173 /* then check to see if the element's name is already taken in the bin,
1174 * we can safely take the lock here. This check is probably bogus because
1175 * you can safely change the element name after this check and before setting
1176 * the object parent. The window is very small though... */
1177 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1178 goto duplicate_name;
1180 /* set the element's parent and add the element to the bin's list of children */
1181 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1182 GST_OBJECT_CAST (bin))))
1185 /* if we add a sink we become a sink */
1186 if (is_sink && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SINK)) {
1187 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1189 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1191 if (is_source && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SOURCE)) {
1192 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1194 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1197 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_PROVIDE_CLOCK)) {
1198 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1200 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1201 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1204 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_REQUIRE_CLOCK)) {
1205 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1206 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1209 bin->children = g_list_prepend (bin->children, element);
1211 bin->children_cookie++;
1212 if (!GST_BIN_IS_NO_RESYNC (bin))
1213 bin->priv->structure_cookie++;
1215 /* distribute the bus */
1216 gst_element_set_bus (element, bin->child_bus);
1218 /* propagate the current base_time, start_time and clock */
1219 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1220 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1221 /* it's possible that the element did not accept the clock but
1222 * that is not important right now. When the pipeline goes to PLAYING,
1223 * a new clock will be selected */
1224 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1226 /* get the element's list of contexts before propagating our own */
1227 elem_contexts = gst_element_get_contexts (element);
1228 for (l = GST_ELEMENT_CAST (bin)->contexts; l; l = l->next)
1229 gst_element_set_context (element, l->data);
1231 need_context_messages = NULL;
1232 for (l = elem_contexts; l; l = l->next) {
1233 GstContext *replacement, *context = l->data;
1234 const gchar *context_type;
1236 context_type = gst_context_get_context_type (context);
1238 /* we already set this context above? */
1240 gst_element_get_context_unlocked (GST_ELEMENT (bin), context_type);
1242 gst_context_unref (replacement);
1247 /* ask our parent for the context */
1248 msg = gst_message_new_need_context (GST_OBJECT_CAST (bin), context_type);
1249 s = (GstStructure *) gst_message_get_structure (msg);
1250 gst_structure_set (s, "bin.old.context", GST_TYPE_CONTEXT, context, NULL);
1252 need_context_messages = g_list_prepend (need_context_messages, msg);
1257 /* set the cached index on the children */
1258 if (bin->priv->index)
1259 gst_element_set_index (element, bin->priv->index);
1262 ret = GST_STATE_RETURN (bin);
1263 /* no need to update the state if we are in error */
1264 if (ret == GST_STATE_CHANGE_FAILURE)
1265 goto no_state_recalc;
1267 /* update the bin state, the new element could have been an ASYNC or
1268 * NO_PREROLL element */
1269 ret = GST_STATE_RETURN (element);
1270 GST_DEBUG_OBJECT (bin, "added %s element",
1271 gst_element_state_change_return_get_name (ret));
1274 case GST_STATE_CHANGE_ASYNC:
1276 /* create message to track this aync element when it posts an async-done
1278 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1281 case GST_STATE_CHANGE_NO_PREROLL:
1282 /* ignore all async elements we might have and commit our state */
1283 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1285 case GST_STATE_CHANGE_FAILURE:
1292 GST_OBJECT_UNLOCK (bin);
1294 for (l = need_context_messages; l; l = l->next) {
1295 GstMessage *msg = l->data;
1297 const gchar *context_type;
1298 GstContext *replacement, *context;
1300 gst_message_parse_context_type (msg, &context_type);
1302 GST_LOG_OBJECT (bin, "asking parent for context type: %s "
1303 "from %" GST_PTR_FORMAT, context_type, element);
1305 s = (GstStructure *) gst_message_get_structure (msg);
1306 gst_structure_get (s, "bin.old.context", GST_TYPE_CONTEXT, &context, NULL);
1307 gst_structure_remove_field (s, "bin.old.context");
1308 /* Keep the msg around while we still need access to the context_type */
1309 gst_element_post_message (GST_ELEMENT_CAST (bin), gst_message_ref (msg));
1311 /* lock to avoid losing a potential write */
1312 GST_OBJECT_LOCK (bin);
1314 gst_element_get_context_unlocked (GST_ELEMENT_CAST (bin), context_type);
1315 gst_message_unref (msg);
1318 /* we got the context set from GstElement::set_context */
1319 gst_context_unref (replacement);
1320 GST_OBJECT_UNLOCK (bin);
1322 /* Propagate the element's context upwards */
1323 GST_LOG_OBJECT (bin, "propagating existing context type: %s %p "
1324 "from %" GST_PTR_FORMAT, context_type, context, element);
1326 gst_bin_update_context_unlocked (bin, context);
1329 gst_message_new_have_context (GST_OBJECT_CAST (bin),
1330 gst_context_ref (context));
1331 GST_OBJECT_UNLOCK (bin);
1332 gst_element_post_message (GST_ELEMENT_CAST (bin), msg);
1334 gst_context_unref (context);
1336 g_list_free_full (elem_contexts, (GDestroyNotify) gst_context_unref);
1337 g_list_free (need_context_messages);
1339 /* post the messages on the bus of the element so that the bin can handle
1342 gst_element_post_message (element, clock_message);
1345 gst_element_post_message (element, async_message);
1347 /* unlink all linked pads */
1348 it = gst_element_iterate_pads (element);
1349 while (gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads,
1350 NULL) == GST_ITERATOR_RESYNC)
1351 gst_iterator_resync (it);
1352 gst_iterator_free (it);
1354 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1357 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1358 gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
1361 gst_bin_do_deep_add_remove (bin, gst_bin_signals[DEEP_ELEMENT_ADDED],
1362 "deep-element-added", element);
1368 /* ERROR handling here */
1371 GST_OBJECT_LOCK (bin);
1372 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1373 GST_OBJECT_UNLOCK (bin);
1374 gst_object_ref_sink (element);
1375 gst_object_unref (element);
1380 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1381 elem_name, GST_ELEMENT_NAME (bin));
1382 GST_OBJECT_UNLOCK (bin);
1384 gst_object_ref_sink (element);
1385 gst_object_unref (element);
1390 g_warning ("Element '%s' already has parent", elem_name);
1391 GST_OBJECT_UNLOCK (bin);
1398 * gst_bin_set_suppressed_flags:
1400 * @flags: the #GstElementFlags to suppress
1402 * Suppress the given flags on the bin. #GstElementFlags of a
1403 * child element are propagated when it is added to the bin.
1404 * When suppressed flags are set, those specified flags will
1405 * not be propagated to the bin.
1412 gst_bin_set_suppressed_flags (GstBin * bin, GstElementFlags flags)
1414 g_return_if_fail (GST_IS_BIN (bin));
1416 GST_OBJECT_LOCK (bin);
1417 bin->priv->suppressed_flags = bin->priv->suppressed_flags | flags;
1418 GST_OBJECT_UNLOCK (bin);
1420 GST_DEBUG_OBJECT (bin, "Set suppressed flags(0x%x) to bin '%s'", flags,
1421 GST_ELEMENT_NAME (bin));
1425 * gst_bin_get_suppressed_flags:
1428 * Return the suppressed flags of the bin.
1432 * Returns: the bin's suppressed #GstElementFlags.
1437 gst_bin_get_suppressed_flags (GstBin * bin)
1439 GstElementFlags res;
1441 g_return_val_if_fail (GST_IS_BIN (bin), 0);
1443 GST_OBJECT_LOCK (bin);
1444 res = bin->priv->suppressed_flags;
1445 GST_OBJECT_UNLOCK (bin);
1450 /* signal vfunc, will be called when a new element was added */
1452 gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
1457 parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
1458 if (parent_bin == NULL) {
1459 GST_LOG_OBJECT (bin, "no parent, reached top-level");
1463 GST_LOG_OBJECT (parent_bin, "emitting deep-element-added for element "
1464 "%" GST_PTR_FORMAT " which has just been added to %" GST_PTR_FORMAT,
1467 g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_ADDED], 0, sub_bin,
1470 gst_object_unref (parent_bin);
1473 /* signal vfunc, will be called when an element was removed */
1475 gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
1480 parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
1481 if (parent_bin == NULL) {
1482 GST_LOG_OBJECT (bin, "no parent, reached top-level");
1486 GST_LOG_OBJECT (parent_bin, "emitting deep-element-removed for element "
1487 "%" GST_PTR_FORMAT " which has just been removed from %" GST_PTR_FORMAT,
1490 g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_REMOVED], 0, sub_bin,
1493 gst_object_unref (parent_bin);
1499 * @element: (transfer floating): the #GstElement to add
1501 * Adds the given element to the bin. Sets the element's parent, and thus
1502 * takes ownership of the element. An element can only be added to one bin.
1504 * If the element's pads are linked to other pads, the pads will be unlinked
1505 * before the element is added to the bin.
1507 * > When you add an element to an already-running pipeline, you will have to
1508 * > take care to set the state of the newly-added element to the desired
1509 * > state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1510 * > with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1511 * > The bin or pipeline will not take care of this for you.
1515 * Returns: %TRUE if the element could be added, %FALSE if
1516 * the bin does not want to accept the element.
1519 gst_bin_add (GstBin * bin, GstElement * element)
1521 GstBinClass *bclass;
1524 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1525 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1526 g_return_val_if_fail (GST_ELEMENT_CAST (bin) != element, FALSE);
1528 bclass = GST_BIN_GET_CLASS (bin);
1530 if (G_UNLIKELY (bclass->add_element == NULL))
1533 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1534 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1535 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1537 GST_TRACER_BIN_ADD_PRE (bin, element);
1538 result = bclass->add_element (bin, element);
1539 GST_TRACER_BIN_ADD_POST (bin, element, result);
1543 /* ERROR handling */
1546 g_warning ("adding elements to bin '%s' is not supported",
1547 GST_ELEMENT_NAME (bin));
1548 gst_object_ref_sink (element);
1549 gst_object_unref (element);
1554 /* remove an element from the bin
1559 gst_bin_remove_func (GstBin * bin, GstElement * element)
1563 gboolean is_sink, is_source, provides_clock, requires_clock;
1564 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1565 GstMessage *clock_message = NULL;
1566 GstClock **provided_clock_p;
1567 GstElement **clock_provider_p;
1569 gboolean other_async, this_async, have_no_preroll;
1570 GstStateChangeReturn ret;
1572 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1574 /* we obviously can't remove ourself from ourself */
1575 if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
1576 goto removing_itself;
1578 GST_OBJECT_LOCK (bin);
1580 GST_OBJECT_LOCK (element);
1581 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1583 if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
1586 /* remove the parent ref */
1587 GST_OBJECT_PARENT (element) = NULL;
1589 /* grab element name so we can print it */
1590 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1591 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1593 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1595 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1596 GST_OBJECT_UNLOCK (element);
1600 othersource = FALSE;
1601 otherprovider = FALSE;
1602 otherrequirer = FALSE;
1603 have_no_preroll = FALSE;
1604 /* iterate the elements, we collect which ones are async and no_preroll. We
1605 * also remove the element when we find it. */
1606 for (walk = bin->children; walk; walk = next) {
1607 GstElement *child = GST_ELEMENT_CAST (walk->data);
1609 next = g_list_next (walk);
1611 if (child == element) {
1613 /* remove the element */
1614 bin->children = g_list_delete_link (bin->children, walk);
1616 gboolean child_sink, child_source, child_provider, child_requirer;
1618 GST_OBJECT_LOCK (child);
1619 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1620 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1622 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1624 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1625 /* when we remove a sink, check if there are other sinks. */
1626 if (is_sink && !othersink && child_sink)
1628 if (is_source && !othersource && child_source)
1630 if (provides_clock && !otherprovider && child_provider)
1631 otherprovider = TRUE;
1632 if (requires_clock && !otherrequirer && child_requirer)
1633 otherrequirer = TRUE;
1634 /* check if we have NO_PREROLL children */
1635 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1636 have_no_preroll = TRUE;
1637 GST_OBJECT_UNLOCK (child);
1641 /* the element must have been in the bin's list of children */
1642 if (G_UNLIKELY (!found))
1645 /* we now removed the element from the list of elements, increment the cookie
1646 * so that others can detect a change in the children list. */
1648 bin->children_cookie++;
1649 if (!GST_BIN_IS_NO_RESYNC (bin))
1650 bin->priv->structure_cookie++;
1652 if (is_sink && !othersink
1653 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SINK)) {
1654 /* we're not a sink anymore */
1655 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1656 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1658 if (is_source && !othersource
1659 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SOURCE)) {
1660 /* we're not a source anymore */
1661 GST_DEBUG_OBJECT (bin, "we removed the last source");
1662 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1664 if (provides_clock && !otherprovider
1665 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_PROVIDE_CLOCK)) {
1666 /* we're not a clock provider anymore */
1667 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1668 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1670 if (requires_clock && !otherrequirer
1671 && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_REQUIRE_CLOCK)) {
1672 /* we're not a clock requirer anymore */
1673 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1674 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1677 /* if the clock provider for this element is removed, we lost
1678 * the clock as well, we need to inform the parent of this
1679 * so that it can select a new clock */
1680 if (bin->clock_provider == element) {
1681 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1682 bin->clock_dirty = TRUE;
1684 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1685 provided_clock_p = &bin->provided_clock;
1686 clock_provider_p = &bin->clock_provider;
1687 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1688 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1691 /* remove messages for the element, if there was a pending ASYNC_START
1692 * message we must see if removing the element caused the bin to lose its
1695 other_async = FALSE;
1696 for (walk = bin->messages; walk; walk = next) {
1697 GstMessage *message = (GstMessage *) walk->data;
1698 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1701 next = g_list_next (walk);
1704 switch (GST_MESSAGE_TYPE (message)) {
1705 case GST_MESSAGE_ASYNC_START:
1711 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1713 case GST_MESSAGE_STRUCTURE_CHANGE:
1717 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1719 /* it's unlikely that this message is still in the list of messages
1720 * because this would mean that a link/unlink is busy in another thread
1721 * while we remove the element. We still have to remove the message
1722 * because we might not receive the done message anymore when the element
1723 * is removed from the bin. */
1724 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1725 if (owner == element)
1736 /* delete all message types */
1737 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1738 message, elem_name);
1739 bin->messages = g_list_delete_link (bin->messages, walk);
1740 gst_message_unref (message);
1744 /* get last return */
1745 ret = GST_STATE_RETURN (bin);
1747 /* no need to update the state if we are in error */
1748 if (ret == GST_STATE_CHANGE_FAILURE)
1749 goto no_state_recalc;
1751 if (!other_async && this_async) {
1752 /* all other elements were not async and we removed the async one,
1753 * handle the async-done case because we are not async anymore now. */
1754 GST_DEBUG_OBJECT (bin,
1755 "we removed the last async element, have no_preroll %d",
1758 /* the current state return of the bin depends on if there are no_preroll
1759 * elements in the pipeline or not */
1760 if (have_no_preroll)
1761 ret = GST_STATE_CHANGE_NO_PREROLL;
1763 ret = GST_STATE_CHANGE_SUCCESS;
1765 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1767 GST_DEBUG_OBJECT (bin,
1768 "recalc state preroll: %d, other async: %d, this async %d",
1769 have_no_preroll, other_async, this_async);
1771 if (have_no_preroll) {
1772 ret = GST_STATE_CHANGE_NO_PREROLL;
1773 } else if (other_async) {
1774 /* there are other async elements and we were not doing an async state
1775 * change, change our pending state and go async */
1776 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1777 GST_STATE_NEXT (bin) = GST_STATE (bin);
1778 GST_STATE_PENDING (bin) = GST_STATE (bin);
1780 ret = GST_STATE_CHANGE_ASYNC;
1782 GST_STATE_RETURN (bin) = ret;
1786 gst_element_set_bus (element, NULL);
1787 /* Clear the clock we provided to the element */
1788 gst_element_set_clock (element, NULL);
1789 GST_OBJECT_UNLOCK (bin);
1792 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1794 /* unlink all linked pads */
1795 it = gst_element_iterate_pads (element);
1796 while (gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads,
1797 NULL) == GST_ITERATOR_RESYNC)
1798 gst_iterator_resync (it);
1799 gst_iterator_free (it);
1801 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1804 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1805 gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
1808 gst_bin_do_deep_add_remove (bin, gst_bin_signals[DEEP_ELEMENT_REMOVED],
1809 "deep-element-removed", element);
1812 /* element is really out of our control now */
1813 gst_object_unref (element);
1817 /* ERROR handling */
1820 GST_OBJECT_LOCK (bin);
1821 g_warning ("Cannot remove bin '%s' from itself", GST_ELEMENT_NAME (bin));
1822 GST_OBJECT_UNLOCK (bin);
1827 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1828 GST_ELEMENT_NAME (bin));
1829 GST_OBJECT_UNLOCK (element);
1830 GST_OBJECT_UNLOCK (bin);
1839 * @element: (transfer none): the #GstElement to remove
1841 * Removes the element from the bin, unparenting it as well.
1842 * Unparenting the element means that the element will be dereferenced,
1843 * so if the bin holds the only reference to the element, the element
1844 * will be freed in the process of removing it from the bin. If you
1845 * want the element to still exist after removing, you need to call
1846 * gst_object_ref() before removing it from the bin.
1848 * If the element's pads are linked to other pads, the pads will be unlinked
1849 * before the element is removed from the bin.
1853 * Returns: %TRUE if the element could be removed, %FALSE if
1854 * the bin does not want to remove the element.
1857 gst_bin_remove (GstBin * bin, GstElement * element)
1859 GstBinClass *bclass;
1862 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1863 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1864 g_return_val_if_fail (GST_ELEMENT_CAST (bin) != element, FALSE);
1866 bclass = GST_BIN_GET_CLASS (bin);
1868 if (G_UNLIKELY (bclass->remove_element == NULL))
1871 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1872 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1874 GST_TRACER_BIN_REMOVE_PRE (bin, element);
1875 result = bclass->remove_element (bin, element);
1876 GST_TRACER_BIN_REMOVE_POST (bin, result);
1880 /* ERROR handling */
1883 g_warning ("removing elements from bin '%s' is not supported",
1884 GST_ELEMENT_NAME (bin));
1890 * gst_bin_iterate_elements:
1893 * Gets an iterator for the elements in this bin.
1895 * MT safe. Caller owns returned value.
1897 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1901 gst_bin_iterate_elements (GstBin * bin)
1903 GstIterator *result;
1905 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1907 GST_OBJECT_LOCK (bin);
1908 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1909 GST_OBJECT_GET_LOCK (bin),
1910 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1911 GST_OBJECT_UNLOCK (bin);
1916 static GstIteratorItem
1917 iterate_child_recurse (GstIterator * it, const GValue * item)
1919 GstElement *child = g_value_get_object (item);
1921 if (GST_IS_BIN (child)) {
1922 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1924 gst_iterator_push (it, other);
1926 return GST_ITERATOR_ITEM_PASS;
1930 * gst_bin_iterate_recurse:
1933 * Gets an iterator for the elements in this bin.
1934 * This iterator recurses into GstBin children.
1936 * MT safe. Caller owns returned value.
1938 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1942 gst_bin_iterate_recurse (GstBin * bin)
1944 GstIterator *result;
1946 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1948 GST_OBJECT_LOCK (bin);
1949 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1950 GST_OBJECT_GET_LOCK (bin),
1951 &bin->children_cookie,
1953 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1954 GST_OBJECT_UNLOCK (bin);
1959 /* returns 0 when TRUE because this is a GCompareFunc */
1962 bin_element_is_sink (GstElement * child, GstBin * bin)
1966 /* we lock the child here for the remainder of the function to
1967 * get its name and flag safely. */
1968 GST_OBJECT_LOCK (child);
1969 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1971 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1972 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1974 GST_OBJECT_UNLOCK (child);
1975 return is_sink ? 0 : 1;
1979 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1981 GstBin *bin = g_value_get_object (vbin);
1982 GstElement *child = g_value_get_object (vchild);
1984 return (bin_element_is_sink (child, bin));
1988 * gst_bin_iterate_sinks:
1991 * Gets an iterator for all elements in the bin that have the
1992 * #GST_ELEMENT_FLAG_SINK flag set.
1994 * MT safe. Caller owns returned value.
1996 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
2000 gst_bin_iterate_sinks (GstBin * bin)
2002 GstIterator *children;
2003 GstIterator *result;
2004 GValue vbin = { 0, };
2006 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2008 g_value_init (&vbin, GST_TYPE_BIN);
2009 g_value_set_object (&vbin, bin);
2011 children = gst_bin_iterate_elements (bin);
2012 result = gst_iterator_filter (children,
2013 (GCompareFunc) sink_iterator_filter, &vbin);
2015 g_value_unset (&vbin);
2020 /* returns 0 when TRUE because this is a GCompareFunc */
2023 bin_element_is_src (GstElement * child, GstBin * bin)
2027 /* we lock the child here for the remainder of the function to
2028 * get its name and other info safely. */
2029 GST_OBJECT_LOCK (child);
2030 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
2032 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2033 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
2035 GST_OBJECT_UNLOCK (child);
2036 return is_src ? 0 : 1;
2040 src_iterator_filter (const GValue * vchild, GValue * vbin)
2042 GstBin *bin = g_value_get_object (vbin);
2043 GstElement *child = g_value_get_object (vchild);
2045 return (bin_element_is_src (child, bin));
2049 * gst_bin_iterate_sources:
2052 * Gets an iterator for all elements in the bin that have the
2053 * #GST_ELEMENT_FLAG_SOURCE flag set.
2055 * MT safe. Caller owns returned value.
2057 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
2061 gst_bin_iterate_sources (GstBin * bin)
2063 GstIterator *children;
2064 GstIterator *result;
2065 GValue vbin = { 0, };
2067 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2069 g_value_init (&vbin, GST_TYPE_BIN);
2070 g_value_set_object (&vbin, bin);
2072 children = gst_bin_iterate_elements (bin);
2073 result = gst_iterator_filter (children,
2074 (GCompareFunc) src_iterator_filter, &vbin);
2076 g_value_unset (&vbin);
2084 static GstStateChangeReturn
2085 gst_bin_get_state_func (GstElement * element, GstState * state,
2086 GstState * pending, GstClockTime timeout)
2088 GstStateChangeReturn ret;
2090 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
2093 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
2099 /***********************************************
2100 * Topologically sorted iterator
2101 * see http://en.wikipedia.org/wiki/Topological_sorting
2103 * For each element in the graph, an entry is kept in a HashTable
2104 * with its number of srcpad connections (degree).
2105 * We then change state of all elements without dependencies
2106 * (degree 0) and decrement the degree of all elements connected
2107 * on the sinkpads. When an element reaches degree 0, its state is
2109 * When all elements are handled the algorithm stops.
2111 typedef struct _GstBinSortIterator
2114 GQueue queue; /* elements queued for state change */
2115 GstBin *bin; /* bin we iterate */
2116 gint mode; /* adding or removing dependency */
2117 GstElement *best; /* next element with least dependencies */
2118 gint best_deg; /* best degree */
2119 GHashTable *hash; /* hashtable with element dependencies */
2120 gboolean dirty; /* we detected structure change */
2121 } GstBinSortIterator;
2124 copy_to_queue (gpointer data, gpointer user_data)
2126 GstElement *element = data;
2127 GQueue *queue = user_data;
2129 gst_object_ref (element);
2130 g_queue_push_tail (queue, element);
2134 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
2135 GstBinSortIterator * copy)
2137 GHashTableIter iter;
2138 gpointer key, value;
2140 g_queue_init (©->queue);
2141 g_queue_foreach ((GQueue *) & it->queue, copy_to_queue, ©->queue);
2143 copy->bin = gst_object_ref (it->bin);
2145 copy->best = gst_object_ref (it->best);
2147 copy->hash = g_hash_table_new (NULL, NULL);
2148 g_hash_table_iter_init (&iter, it->hash);
2149 while (g_hash_table_iter_next (&iter, &key, &value))
2150 g_hash_table_insert (copy->hash, key, value);
2153 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
2154 #define HASH_SET_DEGREE(bit, elem, deg) \
2155 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
2156 #define HASH_GET_DEGREE(bit, elem) \
2157 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
2159 /* add element to queue of next elements in the iterator.
2160 * We push at the tail to give higher priority elements a
2163 add_to_queue (GstBinSortIterator * bit, GstElement * element)
2165 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
2166 GST_ELEMENT_NAME (element));
2167 gst_object_ref (element);
2168 g_queue_push_tail (&bit->queue, element);
2169 HASH_SET_DEGREE (bit, element, -1);
2173 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
2177 if ((find = g_queue_find (&bit->queue, element))) {
2178 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
2179 GST_ELEMENT_NAME (element));
2181 g_queue_delete_link (&bit->queue, find);
2182 gst_object_unref (element);
2184 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
2185 GST_ELEMENT_NAME (element));
2189 /* clear the queue, unref all objects as we took a ref when
2190 * we added them to the queue */
2192 clear_queue (GQueue * queue)
2196 while ((p = g_queue_pop_head (queue)))
2197 gst_object_unref (p);
2200 /* set all degrees to 0. Elements marked as a sink are
2201 * added to the queue immediately. Since we only look at the SINK flag of the
2202 * element, it is possible that we add non-sinks to the queue. These will be
2203 * removed from the queue again when we can prove that it provides data for some
2206 reset_degree (GstElement * element, GstBinSortIterator * bit)
2210 /* sinks are added right away */
2211 GST_OBJECT_LOCK (element);
2212 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
2213 GST_OBJECT_UNLOCK (element);
2216 add_to_queue (bit, element);
2218 /* others are marked with 0 and handled when sinks are done */
2219 HASH_SET_DEGREE (bit, element, 0);
2223 /* adjust the degree of all elements connected to the given
2224 * element. If a degree of an element drops to 0, it is
2225 * added to the queue of elements to schedule next.
2227 * We have to make sure not to cross the bin boundary this element
2231 update_degree (GstElement * element, GstBinSortIterator * bit)
2233 gboolean linked = FALSE;
2235 GST_OBJECT_LOCK (element);
2236 /* don't touch degree if element has no sinkpads */
2237 if (element->numsinkpads != 0) {
2238 /* loop over all sinkpads, decrement degree for all connected
2239 * elements in this bin */
2242 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
2245 pad = GST_PAD_CAST (pads->data);
2247 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
2248 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
2249 GST_MESSAGE_STRUCTURE_CHANGE))) {
2250 /* mark the iterator as dirty because we won't be updating the degree
2251 * of the peer parent now. This would result in the 'loop detected'
2252 * later on because the peer parent element could become the best next
2253 * element with a degree > 0. We will simply continue our state
2254 * changes and we'll eventually resync when the unlink completed and
2255 * the iterator cookie is updated. */
2260 if ((peer = gst_pad_get_peer (pad))) {
2261 GstElement *peer_element;
2263 if ((peer_element = gst_pad_get_parent_element (peer))) {
2264 GST_OBJECT_LOCK (peer_element);
2265 /* check that we don't go outside of this bin */
2266 if (GST_OBJECT_CAST (peer_element)->parent ==
2267 GST_OBJECT_CAST (bit->bin)) {
2268 gint old_deg, new_deg;
2270 old_deg = HASH_GET_DEGREE (bit, peer_element);
2272 /* check to see if we added an element as sink that was not really a
2273 * sink because it was connected to some other element. */
2274 if (old_deg == -1) {
2275 remove_from_queue (bit, peer_element);
2278 new_deg = old_deg + bit->mode;
2280 GST_DEBUG_OBJECT (bit->bin,
2281 "change element %s, degree %d->%d, linked to %s",
2282 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
2283 GST_ELEMENT_NAME (element));
2285 /* update degree, it is possible that an element was in 0 and
2286 * reaches -1 here. This would mean that the element had no sinkpads
2287 * but became linked while the state change was happening. We will
2288 * resync on this with the structure change message. */
2290 /* degree hit 0, add to queue */
2291 add_to_queue (bit, peer_element);
2293 HASH_SET_DEGREE (bit, peer_element, new_deg);
2297 GST_OBJECT_UNLOCK (peer_element);
2298 gst_object_unref (peer_element);
2300 gst_object_unref (peer);
2305 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
2306 GST_ELEMENT_NAME (element));
2308 GST_OBJECT_UNLOCK (element);
2311 /* find the next best element not handled yet. This is the one
2312 * with the lowest non-negative degree */
2314 find_element (GstElement * element, GstBinSortIterator * bit)
2318 /* element is already handled */
2319 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
2322 /* first element or element with smaller degree */
2323 if (bit->best == NULL || bit->best_deg > degree) {
2324 bit->best = element;
2325 bit->best_deg = degree;
2326 } else if (bit->best_deg == degree
2327 && GST_OBJECT_FLAG_IS_SET (bit->best, GST_ELEMENT_FLAG_SOURCE)
2328 && !GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE)) {
2329 /* If two elements have the same degree, we want to ensure we
2330 * return non-source elements first. */
2331 bit->best = element;
2335 /* get next element in iterator. */
2336 static GstIteratorResult
2337 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2340 GstBin *bin = bit->bin;
2342 /* empty queue, we have to find a next best element */
2343 if (g_queue_is_empty (&bit->queue)) {
2345 bit->best_deg = G_MAXINT;
2346 g_list_foreach (bin->children, (GFunc) find_element, bit);
2347 if ((best = bit->best)) {
2348 /* when we detected an unlink, don't warn because our degrees might be
2349 * screwed up. We will resync later */
2350 if (bit->best_deg != 0 && !bit->dirty) {
2351 /* we don't fail on this one yet */
2352 GST_WARNING_OBJECT (bin, "loop dected in graph");
2353 g_warning ("loop detected in the graph of bin '%s'!!",
2354 GST_ELEMENT_NAME (bin));
2356 /* best unhandled element, schedule as next element */
2357 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2358 GST_ELEMENT_NAME (best));
2359 HASH_SET_DEGREE (bit, best, -1);
2360 g_value_set_object (result, best);
2362 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2363 /* no more unhandled elements, we are done */
2364 return GST_ITERATOR_DONE;
2367 /* everything added to the queue got reffed */
2368 best = g_queue_pop_head (&bit->queue);
2369 g_value_set_object (result, best);
2370 gst_object_unref (best);
2373 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2374 /* update degrees of linked elements */
2375 update_degree (best, bit);
2377 return GST_ITERATOR_OK;
2380 /* clear queues, recalculate the degrees and restart. */
2382 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2384 GstBin *bin = bit->bin;
2386 GST_DEBUG_OBJECT (bin, "resync");
2388 clear_queue (&bit->queue);
2390 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2391 /* calc degrees, incrementing */
2393 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2394 /* for the rest of the function we decrement the degrees */
2398 /* clear queues, unref bin and free iterator. */
2400 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2402 GstBin *bin = bit->bin;
2404 GST_DEBUG_OBJECT (bin, "free");
2405 clear_queue (&bit->queue);
2406 g_hash_table_destroy (bit->hash);
2407 gst_object_unref (bin);
2410 /* should be called with the bin LOCK held */
2411 static GstIterator *
2412 gst_bin_sort_iterator_new (GstBin * bin)
2414 GstBinSortIterator *result;
2416 /* we don't need an ItemFunction because we ref the items in the _next
2418 result = (GstBinSortIterator *)
2419 gst_iterator_new (sizeof (GstBinSortIterator),
2421 GST_OBJECT_GET_LOCK (bin),
2422 &bin->priv->structure_cookie,
2423 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2424 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2425 (GstIteratorItemFunction) NULL,
2426 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2427 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2428 g_queue_init (&result->queue);
2429 result->hash = g_hash_table_new (NULL, NULL);
2430 gst_object_ref (bin);
2432 gst_bin_sort_iterator_resync (result);
2434 return (GstIterator *) result;
2438 * gst_bin_iterate_sorted:
2441 * Gets an iterator for the elements in this bin in topologically
2442 * sorted order. This means that the elements are returned from
2443 * the most downstream elements (sinks) to the sources.
2445 * This function is used internally to perform the state changes
2446 * of the bin elements and for clock selection.
2448 * MT safe. Caller owns returned value.
2450 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
2454 gst_bin_iterate_sorted (GstBin * bin)
2456 GstIterator *result;
2458 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2460 GST_OBJECT_LOCK (bin);
2461 result = gst_bin_sort_iterator_new (bin);
2462 GST_OBJECT_UNLOCK (bin);
2467 static GstStateChangeReturn
2468 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2469 GstClockTime base_time, GstClockTime start_time, GstState current,
2472 GstStateChangeReturn ret;
2473 GstState child_current, child_pending;
2477 GST_STATE_LOCK (element);
2479 GST_OBJECT_LOCK (element);
2480 /* set base_time and start time on child */
2481 GST_ELEMENT_START_TIME (element) = start_time;
2482 element->base_time = base_time;
2483 /* peel off the locked flag */
2484 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2485 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2486 ret = GST_STATE_RETURN (element);
2487 child_current = GST_STATE (element);
2488 child_pending = GST_STATE_PENDING (element);
2489 GST_OBJECT_UNLOCK (element);
2491 /* skip locked elements */
2492 if (G_UNLIKELY (locked))
2495 /* if the element was no preroll, just start changing the state regardless
2496 * if it had async elements (in the case of a bin) because they won't preroll
2498 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2499 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2503 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2504 "current %s pending %s, desired next %s",
2505 gst_element_state_get_name (child_current),
2506 gst_element_state_get_name (child_pending),
2507 gst_element_state_get_name (next));
2509 /* always recurse into bins so that we can set the base time */
2510 if (GST_IS_BIN (element))
2513 /* Try not to change the state of elements that are already in the state we're
2515 if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
2516 /* child is already at the requested state, return previous return. Note that
2517 * if the child has a pending state to next, we will still call the
2518 * set_state function */
2520 } else if (next > current) {
2521 /* upward state change */
2522 if (child_pending == GST_STATE_VOID_PENDING) {
2523 /* .. and the child is not busy doing anything */
2524 if (child_current > next) {
2525 /* .. and is already past the requested state, assume it got there
2527 ret = GST_STATE_CHANGE_SUCCESS;
2530 } else if (child_pending > child_current) {
2531 /* .. and the child is busy going upwards */
2532 if (child_current >= next) {
2533 /* .. and is already past the requested state, assume it got there
2535 ret = GST_STATE_CHANGE_SUCCESS;
2539 /* .. and the child is busy going downwards */
2540 if (child_current > next) {
2541 /* .. and is already past the requested state, assume it got there
2543 ret = GST_STATE_CHANGE_SUCCESS;
2547 } else if (next < current) {
2548 /* downward state change */
2549 if (child_pending == GST_STATE_VOID_PENDING) {
2550 /* .. and the child is not busy doing anything */
2551 if (child_current < next) {
2552 /* .. and is already past the requested state, assume it got there
2554 ret = GST_STATE_CHANGE_SUCCESS;
2557 } else if (child_pending < child_current) {
2558 /* .. and the child is busy going downwards */
2559 if (child_current <= next) {
2560 /* .. and is already past the requested state, assume it got there
2562 ret = GST_STATE_CHANGE_SUCCESS;
2566 /* .. and the child is busy going upwards */
2567 if (child_current < next) {
2568 /* .. and is already past the requested state, assume it got there
2570 ret = GST_STATE_CHANGE_SUCCESS;
2577 GST_OBJECT_LOCK (bin);
2578 /* the element was busy with an upwards async state change, we must wait for
2579 * an ASYNC_DONE message before we attempt to change the state. */
2581 find_message (bin, GST_OBJECT_CAST (element),
2582 GST_MESSAGE_ASYNC_START))) {
2583 #ifndef GST_DISABLE_GST_DEBUG
2584 GstMessage *message = GST_MESSAGE_CAST (found->data);
2586 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2587 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2589 /* only wait for upward state changes */
2590 if (next > current) {
2591 /* We found an async element check if we can force its state to change or
2592 * if we have to wait for it to preroll. */
2596 GST_OBJECT_UNLOCK (bin);
2599 GST_DEBUG_OBJECT (bin,
2600 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2601 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2602 GST_TIME_ARGS (base_time));
2605 ret = gst_element_set_state (element, next);
2607 GST_STATE_UNLOCK (element);
2613 GST_DEBUG_OBJECT (element,
2614 "element is locked, return previous return %s",
2615 gst_element_state_change_return_get_name (ret));
2616 GST_STATE_UNLOCK (element);
2621 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2622 "skipping transition from %s to %s",
2623 gst_element_state_get_name (child_current),
2624 gst_element_state_get_name (next));
2625 GST_STATE_UNLOCK (element);
2630 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2631 GST_OBJECT_UNLOCK (bin);
2632 GST_STATE_UNLOCK (element);
2633 return GST_STATE_CHANGE_ASYNC;
2637 /* gst_iterator_fold functions for pads_activate
2638 * Stop the iterator if activating one pad failed, but only if that pad
2639 * has not been removed from the element. */
2641 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2643 GstPad *pad = g_value_get_object (vpad);
2644 gboolean cont = TRUE;
2646 if (!gst_pad_set_active (pad, *active)) {
2647 if (GST_PAD_PARENT (pad) != NULL) {
2649 g_value_set_boolean (ret, FALSE);
2656 /* returns false on error or early cutout of the fold, true if all
2657 * pads in @iter were (de)activated successfully. */
2659 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2661 GstIteratorResult ires;
2664 /* no need to unset this later, it's just a boolean */
2665 g_value_init (&ret, G_TYPE_BOOLEAN);
2666 g_value_set_boolean (&ret, TRUE);
2669 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2672 case GST_ITERATOR_RESYNC:
2673 /* need to reset the result again */
2674 g_value_set_boolean (&ret, TRUE);
2675 gst_iterator_resync (iter);
2677 case GST_ITERATOR_DONE:
2678 /* all pads iterated, return collected value */
2681 /* iterator returned _ERROR or premature end with _OK,
2682 * mark an error and exit */
2683 g_value_set_boolean (&ret, FALSE);
2688 /* return collected value */
2689 return g_value_get_boolean (&ret);
2692 /* is called with STATE_LOCK
2695 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2700 GST_DEBUG_OBJECT (bin, "%s pads", active ? "activate" : "deactivate");
2702 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2703 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2704 gst_iterator_free (iter);
2705 if (G_UNLIKELY (!fold_ok))
2708 GST_DEBUG_OBJECT (bin, "pad %sactivation successful", active ? "" : "de");
2715 GST_DEBUG_OBJECT (bin, "pad %sactivation failed", active ? "" : "de");
2721 * gst_bin_recalculate_latency:
2724 * Query @bin for the current latency using and reconfigures this latency to all the
2725 * elements with a LATENCY event.
2727 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2728 * is posted on the bus.
2730 * This function simply emits the 'do-latency' signal so any custom latency
2731 * calculations will be performed.
2733 * Returns: %TRUE if the latency could be queried and reconfigured.
2736 gst_bin_recalculate_latency (GstBin * bin)
2740 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2741 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2747 gst_bin_do_latency_func (GstBin * bin)
2750 GstElement *element;
2751 GstClockTime min_latency, max_latency;
2754 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2756 element = GST_ELEMENT_CAST (bin);
2758 GST_DEBUG_OBJECT (element, "querying latency");
2760 query = gst_query_new_latency ();
2761 if ((res = gst_element_query (element, query))) {
2764 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2766 GST_DEBUG_OBJECT (element,
2767 "got min latency %" GST_TIME_FORMAT ", max latency %"
2768 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2769 GST_TIME_ARGS (max_latency), live);
2771 if (max_latency < min_latency) {
2772 /* this is an impossible situation, some parts of the pipeline might not
2773 * work correctly. We post a warning for now. */
2774 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2775 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2776 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2777 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2780 /* configure latency on elements */
2781 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2783 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2784 GST_TIME_ARGS (min_latency));
2786 GST_WARNING_OBJECT (element,
2787 "did not really configure latency of %" GST_TIME_FORMAT,
2788 GST_TIME_ARGS (min_latency));
2791 /* this is not a real problem, we just don't configure any latency. */
2792 GST_WARNING_OBJECT (element, "failed to query latency");
2794 gst_query_unref (query);
2800 gst_bin_post_message (GstElement * element, GstMessage * msg)
2802 GstElementClass *pklass = (GstElementClass *) parent_class;
2805 ret = pklass->post_message (element, gst_message_ref (msg));
2807 if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_STATE_CHANGED &&
2808 GST_MESSAGE_SRC (msg) == GST_OBJECT_CAST (element)) {
2809 GstState newstate, pending;
2811 gst_message_parse_state_changed (msg, NULL, &newstate, &pending);
2812 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING) {
2813 GST_BIN_CAST (element)->priv->posted_playing = TRUE;
2814 bin_do_eos (GST_BIN_CAST (element));
2816 GST_BIN_CAST (element)->priv->posted_playing = FALSE;
2820 gst_message_unref (msg);
2826 reset_state (const GValue * data, gpointer user_data)
2828 GstElement *e = g_value_get_object (data);
2829 GstState state = GPOINTER_TO_INT (user_data);
2831 if (gst_element_set_state (e, state) == GST_STATE_CHANGE_FAILURE)
2832 GST_WARNING_OBJECT (e, "Failed to switch back down to %s",
2833 gst_element_state_get_name (state));
2836 static GstStateChangeReturn
2837 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2840 GstStateChangeReturn ret;
2841 GstState current, next;
2842 gboolean have_async;
2843 gboolean have_no_preroll;
2844 GstClockTime base_time, start_time;
2847 GValue data = { 0, };
2849 /* we don't need to take the STATE_LOCK, it is already taken */
2850 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2851 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2853 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2854 "changing state of children from %s to %s",
2855 gst_element_state_get_name (current), gst_element_state_get_name (next));
2857 bin = GST_BIN_CAST (element);
2860 case GST_STATE_PLAYING:
2862 gboolean toplevel, asynchandling;
2864 GST_OBJECT_LOCK (bin);
2865 toplevel = BIN_IS_TOPLEVEL (bin);
2866 asynchandling = bin->priv->asynchandling;
2867 GST_OBJECT_UNLOCK (bin);
2870 gst_bin_recalculate_latency (bin);
2872 gst_element_post_message (element,
2873 gst_message_new_latency (GST_OBJECT_CAST (element)));
2876 case GST_STATE_PAUSED:
2877 /* Clear EOS list on next PAUSED */
2878 GST_OBJECT_LOCK (bin);
2879 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2880 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2881 bin->priv->posted_eos = FALSE;
2882 if (current == GST_STATE_READY)
2883 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
2884 GST_OBJECT_UNLOCK (bin);
2885 if (current == GST_STATE_READY)
2886 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2887 goto activate_failure;
2889 case GST_STATE_READY:
2890 /* Clear message list on next READY */
2891 GST_OBJECT_LOCK (bin);
2892 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2893 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2894 GST_OBJECT_UNLOCK (bin);
2895 /* We might not have reached PAUSED yet due to async errors,
2896 * make sure to always deactivate the pads nonetheless */
2897 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2898 goto activate_failure;
2900 case GST_STATE_NULL:
2901 /* Clear message list on next NULL */
2902 GST_OBJECT_LOCK (bin);
2903 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2904 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2905 GST_OBJECT_UNLOCK (bin);
2906 if (current == GST_STATE_READY) {
2907 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2908 goto activate_failure;
2915 /* this flag is used to make the async state changes return immediately. We
2916 * don't want them to interfere with this state change */
2917 GST_OBJECT_LOCK (bin);
2918 bin->polling = TRUE;
2919 GST_OBJECT_UNLOCK (bin);
2921 /* iterate in state change order */
2922 it = gst_bin_iterate_sorted (bin);
2924 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2925 * Note how we don't reset this value when a resync happens, the reason being
2926 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2927 * even after a resync when the async element is gone */
2931 /* take base_time */
2932 base_time = gst_element_get_base_time (element);
2933 start_time = gst_element_get_start_time (element);
2935 have_no_preroll = FALSE;
2939 switch (gst_iterator_next (it, &data)) {
2940 case GST_ITERATOR_OK:
2944 child = g_value_get_object (&data);
2946 /* set state and base_time now */
2947 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2951 case GST_STATE_CHANGE_SUCCESS:
2952 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2953 "child '%s' changed state to %d(%s) successfully",
2954 GST_ELEMENT_NAME (child), next,
2955 gst_element_state_get_name (next));
2957 case GST_STATE_CHANGE_ASYNC:
2959 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2960 "child '%s' is changing state asynchronously to %s",
2961 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2965 case GST_STATE_CHANGE_FAILURE:{
2968 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2969 "child '%s' failed to go to state %d(%s)",
2970 GST_ELEMENT_NAME (child),
2971 next, gst_element_state_get_name (next));
2973 /* Only fail if the child is still inside
2974 * this bin. It might've been removed already
2975 * because of the error by the bin subclass
2976 * to ignore the error. */
2977 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2978 if (parent == GST_OBJECT_CAST (element)) {
2979 /* element is still in bin, really error now */
2980 gst_object_unref (parent);
2983 /* child removed from bin, let the resync code redo the state
2985 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2986 "child '%s' was removed from the bin",
2987 GST_ELEMENT_NAME (child));
2990 gst_object_unref (parent);
2994 case GST_STATE_CHANGE_NO_PREROLL:
2995 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2996 "child '%s' changed state to %d(%s) successfully without preroll",
2997 GST_ELEMENT_NAME (child), next,
2998 gst_element_state_get_name (next));
2999 have_no_preroll = TRUE;
3002 g_assert_not_reached ();
3005 g_value_reset (&data);
3008 case GST_ITERATOR_RESYNC:
3009 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
3010 gst_iterator_resync (it);
3013 case GST_ITERATOR_DONE:
3014 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
3020 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
3021 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
3024 if (have_no_preroll) {
3025 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
3026 "we have NO_PREROLL elements %s -> NO_PREROLL",
3027 gst_element_state_change_return_get_name (ret));
3028 ret = GST_STATE_CHANGE_NO_PREROLL;
3029 } else if (have_async) {
3030 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
3031 "we have ASYNC elements %s -> ASYNC",
3032 gst_element_state_change_return_get_name (ret));
3033 ret = GST_STATE_CHANGE_ASYNC;
3037 g_value_unset (&data);
3038 gst_iterator_free (it);
3040 GST_OBJECT_LOCK (bin);
3041 bin->polling = FALSE;
3042 /* it's possible that we did not get ASYNC from the children while the bin is
3043 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
3044 * itself as the source. In that case we still want to check if the state
3045 * change completed. */
3046 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
3047 /* no element returned ASYNC and there are no pending async_done messages,
3048 * we can just complete. */
3049 GST_DEBUG_OBJECT (bin, "no async elements");
3052 /* when we get here an ASYNC element was found */
3053 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
3054 /* we ignore ASYNC state changes when we go to READY or NULL */
3055 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
3056 gst_element_state_get_name (GST_STATE_TARGET (bin)));
3060 GST_DEBUG_OBJECT (bin, "check async elements");
3061 /* check if all elements managed to commit their state already */
3062 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3063 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
3064 * all the elements committed their state while we were doing the state
3065 * change. We will still return ASYNC for consistency but we commit the
3066 * state already so that a _get_state() will return immediately. */
3067 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3069 GST_DEBUG_OBJECT (bin, "async elements committed");
3070 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
3071 GST_CLOCK_TIME_NONE);
3075 bin->priv->pending_async_done = FALSE;
3076 GST_OBJECT_UNLOCK (bin);
3078 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
3079 "done changing bin's state from %s to %s, now in %s, ret %s",
3080 gst_element_state_get_name (current),
3081 gst_element_state_get_name (next),
3082 gst_element_state_get_name (GST_STATE (element)),
3083 gst_element_state_change_return_get_name (ret));
3090 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
3091 "failure (de)activating src pads");
3092 return GST_STATE_CHANGE_FAILURE;
3097 if (current < next) {
3098 GstIterator *it = gst_bin_iterate_sorted (GST_BIN (element));
3099 GstIteratorResult ret;
3101 GST_DEBUG_OBJECT (element,
3102 "Bin failed to change state, switching children back to %s",
3103 gst_element_state_get_name (current));
3106 gst_iterator_foreach (it, &reset_state, GINT_TO_POINTER (current));
3107 if (ret != GST_ITERATOR_RESYNC)
3109 gst_iterator_resync (it);
3111 gst_iterator_free (it);
3118 * This function is a utility event handler. It will send the event to all sinks
3119 * or sources and appropriate ghost pads depending on the event-direction.
3121 * Applications are free to override this behaviour and implement their own
3122 * handler, but this will work for pretty much all cases in practice.
3125 gst_bin_send_event (GstElement * element, GstEvent * event)
3127 GstBin *bin = GST_BIN_CAST (element);
3129 gboolean res = TRUE;
3130 gboolean done = FALSE;
3131 GValue data = { 0, };
3133 if (GST_EVENT_IS_DOWNSTREAM (event)) {
3134 iter = gst_bin_iterate_sources (bin);
3135 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
3136 GST_EVENT_TYPE_NAME (event));
3138 iter = gst_bin_iterate_sinks (bin);
3139 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
3140 GST_EVENT_TYPE_NAME (event));
3144 switch (gst_iterator_next (iter, &data)) {
3145 case GST_ITERATOR_OK:
3147 GstElement *child = g_value_get_object (&data);
3149 gst_event_ref (event);
3150 res &= gst_element_send_event (child, event);
3152 GST_LOG_OBJECT (child, "After handling %s event: %d",
3153 GST_EVENT_TYPE_NAME (event), res);
3155 g_value_reset (&data);
3158 case GST_ITERATOR_RESYNC:
3159 gst_iterator_resync (iter);
3162 case GST_ITERATOR_DONE:
3165 case GST_ITERATOR_ERROR:
3166 g_assert_not_reached ();
3170 g_value_unset (&data);
3171 gst_iterator_free (iter);
3173 if (GST_EVENT_IS_DOWNSTREAM (event)) {
3174 iter = gst_element_iterate_sink_pads (GST_ELEMENT (bin));
3175 GST_DEBUG_OBJECT (bin, "Sending %s event to sink pads",
3176 GST_EVENT_TYPE_NAME (event));
3178 iter = gst_element_iterate_src_pads (GST_ELEMENT (bin));
3179 GST_DEBUG_OBJECT (bin, "Sending %s event to src pads",
3180 GST_EVENT_TYPE_NAME (event));
3185 switch (gst_iterator_next (iter, &data)) {
3186 case GST_ITERATOR_OK:
3188 GstPad *pad = g_value_get_object (&data);
3190 gst_event_ref (event);
3191 res &= gst_pad_send_event (pad, event);
3192 GST_LOG_OBJECT (pad, "After handling %s event: %d",
3193 GST_EVENT_TYPE_NAME (event), res);
3196 case GST_ITERATOR_RESYNC:
3197 gst_iterator_resync (iter);
3200 case GST_ITERATOR_DONE:
3203 case GST_ITERATOR_ERROR:
3204 g_assert_not_reached ();
3209 g_value_unset (&data);
3210 gst_iterator_free (iter);
3211 gst_event_unref (event);
3216 /* this is the function called by the threadpool. When async elements commit
3217 * their state, this function will attempt to bring the bin to the next state.
3220 gst_bin_continue_func (GstBin * bin, BinContinueData * data)
3222 GstState current, next, pending;
3223 GstStateChange transition;
3225 pending = data->pending;
3227 GST_DEBUG_OBJECT (bin, "waiting for state lock");
3228 GST_STATE_LOCK (bin);
3230 GST_DEBUG_OBJECT (bin, "doing state continue");
3231 GST_OBJECT_LOCK (bin);
3233 /* if a new state change happened after this thread was scheduled, we return
3235 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
3238 current = GST_STATE (bin);
3239 next = GST_STATE_GET_NEXT (current, pending);
3240 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
3242 GST_STATE_NEXT (bin) = next;
3243 GST_STATE_PENDING (bin) = pending;
3245 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3246 GST_OBJECT_UNLOCK (bin);
3248 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3249 "continue state change %s to %s, final %s",
3250 gst_element_state_get_name (current),
3251 gst_element_state_get_name (next), gst_element_state_get_name (pending));
3253 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
3255 GST_STATE_UNLOCK (bin);
3256 GST_DEBUG_OBJECT (bin, "state continue done");
3262 GST_OBJECT_UNLOCK (bin);
3263 GST_STATE_UNLOCK (bin);
3264 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
3269 static GstBusSyncReply
3270 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
3272 GstBinClass *bclass;
3274 bclass = GST_BIN_GET_CLASS (bin);
3275 if (bclass->handle_message)
3276 bclass->handle_message (bin, message);
3278 gst_message_unref (message);
3280 return GST_BUS_DROP;
3284 free_bin_continue_data (BinContinueData * data)
3286 g_slice_free (BinContinueData, data);
3290 bin_push_state_continue (GstBin * bin, BinContinueData * data)
3292 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
3293 gst_element_call_async (GST_ELEMENT_CAST (bin),
3294 (GstElementCallAsyncFunc) gst_bin_continue_func, data,
3295 (GDestroyNotify) free_bin_continue_data);
3298 /* an element started an async state change, if we were not busy with a state
3299 * change, we perform a lost state.
3300 * This function is called with the OBJECT lock.
3303 bin_handle_async_start (GstBin * bin)
3305 GstState old_state, new_state;
3307 GstMessage *amessage = NULL;
3309 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3312 /* get our toplevel state */
3313 toplevel = BIN_IS_TOPLEVEL (bin);
3315 /* prepare an ASYNC_START message, we always post the start message even if we
3316 * are busy with a state change or when we are NO_PREROLL. */
3318 /* non toplevel bin, prepare async-start for the parent */
3319 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
3321 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
3324 /* async starts are ignored when we are NO_PREROLL */
3325 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
3326 goto was_no_preroll;
3328 old_state = GST_STATE (bin);
3330 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
3331 * PLAYING after optionally redistributing the base_time. */
3332 if (old_state > GST_STATE_PAUSED)
3333 new_state = GST_STATE_PAUSED;
3335 new_state = old_state;
3337 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
3338 "lost state of %s, new %s", gst_element_state_get_name (old_state),
3339 gst_element_state_get_name (new_state));
3341 GST_STATE (bin) = new_state;
3342 GST_STATE_NEXT (bin) = new_state;
3343 GST_STATE_PENDING (bin) = new_state;
3344 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3345 GST_OBJECT_UNLOCK (bin);
3348 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
3353 /* post our ASYNC_START. */
3354 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
3355 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3357 GST_OBJECT_LOCK (bin);
3363 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3368 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3369 GST_OBJECT_UNLOCK (bin);
3374 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
3375 GST_OBJECT_UNLOCK (bin);
3380 /* this function is called when there are no more async elements in the bin. We
3381 * post a state changed message and an ASYNC_DONE message.
3382 * This function is called with the OBJECT lock.
3385 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
3386 gboolean flag_pending, GstClockTime running_time)
3388 GstState current, pending, target;
3389 GstStateChangeReturn old_ret;
3390 GstState old_state, old_next;
3391 gboolean toplevel, state_changed = FALSE;
3392 GstMessage *amessage = NULL;
3393 BinContinueData *cont = NULL;
3395 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3398 pending = GST_STATE_PENDING (bin);
3403 /* check if there is something to commit */
3404 if (pending == GST_STATE_VOID_PENDING)
3405 goto nothing_pending;
3407 old_ret = GST_STATE_RETURN (bin);
3408 GST_STATE_RETURN (bin) = ret;
3410 /* move to the next target state */
3411 target = GST_STATE_TARGET (bin);
3412 pending = GST_STATE_PENDING (bin) = target;
3414 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
3416 old_state = GST_STATE (bin);
3417 /* this is the state we should go to next */
3418 old_next = GST_STATE_NEXT (bin);
3420 if (old_next != GST_STATE_PLAYING) {
3421 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3422 "committing state from %s to %s, old pending %s",
3423 gst_element_state_get_name (old_state),
3424 gst_element_state_get_name (old_next),
3425 gst_element_state_get_name (pending));
3427 /* update current state */
3428 current = GST_STATE (bin) = old_next;
3430 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3431 "setting state from %s to %s, pending %s",
3432 gst_element_state_get_name (old_state),
3433 gst_element_state_get_name (old_state),
3434 gst_element_state_get_name (pending));
3435 current = old_state;
3438 /* get our toplevel state */
3439 toplevel = BIN_IS_TOPLEVEL (bin);
3441 /* see if we reached the final state. If we are not toplevel, we also have to
3442 * stop here, the parent will continue our state. */
3443 if ((pending == current) || !toplevel) {
3444 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3445 "completed state change, pending VOID");
3447 /* mark VOID pending */
3448 pending = GST_STATE_VOID_PENDING;
3449 GST_STATE_PENDING (bin) = pending;
3450 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
3452 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3453 "continue state change, pending %s",
3454 gst_element_state_get_name (pending));
3456 cont = g_slice_new (BinContinueData);
3458 /* cookie to detect concurrent state change */
3459 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3460 /* pending target state */
3461 cont->pending = pending;
3463 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3464 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3467 if (old_next != GST_STATE_PLAYING) {
3468 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3469 state_changed = TRUE;
3472 GST_OBJECT_UNLOCK (bin);
3474 if (state_changed) {
3475 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3479 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3480 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3481 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3484 GST_OBJECT_LOCK (bin);
3486 /* toplevel, start continue state */
3487 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3488 bin_push_state_continue (bin, cont);
3490 GST_DEBUG_OBJECT (bin, "state change complete");
3491 GST_STATE_BROADCAST (bin);
3497 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3502 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3503 /* if we were busy with a state change and we are requested to flag a
3504 * pending async done, we do so here */
3506 bin->priv->pending_async_done = TRUE;
3511 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3517 bin_do_eos (GstBin * bin)
3519 guint32 seqnum = GST_SEQNUM_INVALID;
3522 GST_OBJECT_LOCK (bin);
3523 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3524 * (or we're doing playing to playing and no one else will trigger posting
3525 * EOS for us) we forward the EOS message to the parent bin or application
3527 eos = GST_STATE (bin) == GST_STATE_PLAYING
3528 && (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING ||
3529 GST_STATE_PENDING (bin) == GST_STATE_PLAYING)
3530 && bin->priv->posted_playing && is_eos (bin, &seqnum);
3531 GST_OBJECT_UNLOCK (bin);
3534 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3536 GstMessage *tmessage;
3538 /* Clear out any further messages, and reset posted_eos so we can
3539 detect any new EOS that happens (eg, after a seek). Since all
3540 sinks have now posted an EOS, there will be no further EOS events
3541 seen unless there is a new logical EOS */
3542 GST_OBJECT_LOCK (bin);
3543 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3544 bin->priv->posted_eos = FALSE;
3545 GST_OBJECT_UNLOCK (bin);
3547 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3548 if (seqnum != GST_SEQNUM_INVALID)
3549 gst_message_set_seqnum (tmessage, seqnum);
3550 GST_DEBUG_OBJECT (bin,
3551 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3552 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3554 GST_LOG_OBJECT (bin, "Not forwarding EOS due to in progress state change, "
3555 " or already posted, or waiting for more EOS");
3560 bin_do_stream_start (GstBin * bin)
3562 guint32 seqnum = GST_SEQNUM_INVALID;
3563 gboolean stream_start;
3564 gboolean have_group_id = FALSE;
3567 GST_OBJECT_LOCK (bin);
3568 /* If all sinks are STREAM_START we forward the STREAM_START message
3569 * to the parent bin or application
3571 stream_start = is_stream_start (bin, &seqnum, &have_group_id, &group_id);
3572 GST_OBJECT_UNLOCK (bin);
3575 GstMessage *tmessage;
3577 GST_OBJECT_LOCK (bin);
3578 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
3579 GST_OBJECT_UNLOCK (bin);
3581 tmessage = gst_message_new_stream_start (GST_OBJECT_CAST (bin));
3582 if (seqnum != GST_SEQNUM_INVALID)
3583 gst_message_set_seqnum (tmessage, seqnum);
3585 gst_message_set_group_id (tmessage, group_id);
3587 GST_DEBUG_OBJECT (bin,
3588 "all sinks posted STREAM_START, posting seqnum #%" G_GUINT32_FORMAT,
3590 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3594 /* must be called without the object lock as it posts messages */
3596 bin_do_message_forward (GstBin * bin, GstMessage * message)
3598 if (bin->priv->message_forward) {
3599 GstMessage *forwarded;
3601 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3602 GST_MESSAGE_TYPE_NAME (message));
3604 /* we need to convert these messages to element messages so that our parent
3605 * bin can easily ignore them and so that the application can easily
3606 * distinguish between the internally forwarded and the real messages. */
3607 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3608 gst_structure_new ("GstBinForwarded",
3609 "message", GST_TYPE_MESSAGE, message, NULL));
3611 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3616 gst_bin_update_context (GstBin * bin, GstContext * context)
3618 GST_OBJECT_LOCK (bin);
3619 gst_bin_update_context_unlocked (bin, context);
3620 GST_OBJECT_UNLOCK (bin);
3624 gst_bin_update_context_unlocked (GstBin * bin, GstContext * context)
3626 const gchar *context_type;
3627 GList *l, **contexts;
3629 contexts = &GST_ELEMENT_CAST (bin)->contexts;
3630 context_type = gst_context_get_context_type (context);
3632 GST_DEBUG_OBJECT (bin, "set context %p %" GST_PTR_FORMAT, context,
3633 gst_context_get_structure (context));
3634 for (l = *contexts; l; l = l->next) {
3635 GstContext *tmp = l->data;
3636 const gchar *tmp_type = gst_context_get_context_type (tmp);
3638 /* Always store newest context but never replace
3639 * a persistent one by a non-persistent one */
3640 if (strcmp (context_type, tmp_type) == 0 &&
3641 (gst_context_is_persistent (context) ||
3642 !gst_context_is_persistent (tmp))) {
3643 gst_context_replace ((GstContext **) & l->data, context);
3647 /* Not found? Add */
3649 *contexts = g_list_prepend (*contexts, gst_context_ref (context));
3653 /* handle child messages:
3655 * This method is called synchronously when a child posts a message on
3658 * GST_MESSAGE_EOS: This message is only posted by sinks
3659 * in the PLAYING state. If all sinks posted the EOS message, post
3662 * GST_MESSAGE_STATE_DIRTY: Deprecated
3664 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3665 * element posts segment_start twice, only the last message is kept.
3667 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3668 * with the segment_done message. If there are no more segment_start
3669 * messages, post segment_done message upwards.
3671 * GST_MESSAGE_DURATION_CHANGED: clear any cached durations.
3672 * Whenever someone performs a duration query on the bin, we store the
3673 * result so we can answer it quicker the next time. Any element that
3674 * changes its duration marks our cached values invalid.
3675 * This message is also posted upwards. This is currently disabled
3676 * because too many elements don't post DURATION_CHANGED messages when
3677 * the duration changes.
3679 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3680 * can no longer provide a clock. The default bin behaviour is to
3681 * check if the lost clock was the one provided by the bin. If so and
3682 * we are currently in the PLAYING state, we forward the message to
3684 * This message is also generated when we remove a clock provider from
3685 * a bin. If this message is received by the application, it should
3686 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3687 * and a new base_time distribution.
3689 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3690 * can provide a clock. This mostly happens when we add a new clock
3691 * provider to the bin. The default behaviour of the bin is to mark the
3692 * currently selected clock as dirty, which will perform a clock
3693 * recalculation the next time we are asked to provide a clock.
3694 * This message is never sent to the application but is forwarded to
3697 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3698 * the state of the element and the fact that the element will need a
3699 * new base_time. This message is not forwarded to the application.
3701 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3702 * element when it posted ASYNC_START. If all elements are done, post a
3703 * ASYNC_DONE message to the parent.
3705 * OTHER: post upwards.
3708 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3711 GstMessageType type;
3712 GstMessage *tmessage;
3715 src = GST_MESSAGE_SRC (message);
3716 type = GST_MESSAGE_TYPE (message);
3718 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3719 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3720 GST_MESSAGE_TYPE_NAME (message));
3723 case GST_MESSAGE_ERROR:
3725 GST_OBJECT_LOCK (bin);
3727 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3728 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3729 GST_STATE_BROADCAST (bin);
3730 GST_OBJECT_UNLOCK (bin);
3734 case GST_MESSAGE_EOS:
3737 /* collect all eos messages from the children */
3738 bin_do_message_forward (bin, message);
3739 GST_OBJECT_LOCK (bin);
3740 /* ref message for future use */
3741 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3742 GST_OBJECT_UNLOCK (bin);
3747 case GST_MESSAGE_STREAM_START:
3750 /* collect all stream_start messages from the children */
3751 GST_OBJECT_LOCK (bin);
3752 /* ref message for future use */
3753 bin_replace_message (bin, message, GST_MESSAGE_STREAM_START);
3754 GST_OBJECT_UNLOCK (bin);
3756 bin_do_stream_start (bin);
3759 case GST_MESSAGE_STATE_DIRTY:
3761 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3764 gst_message_unref (message);
3767 case GST_MESSAGE_SEGMENT_START:{
3768 gboolean post = FALSE;
3772 gst_message_parse_segment_start (message, &format, &position);
3773 seqnum = gst_message_get_seqnum (message);
3775 bin_do_message_forward (bin, message);
3777 GST_OBJECT_LOCK (bin);
3778 /* if this is the first segment-start, post to parent but not to the
3780 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3781 (GST_OBJECT_PARENT (bin) != NULL)) {
3784 /* replace any previous segment_start message from this source
3785 * with the new segment start message */
3786 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3787 GST_OBJECT_UNLOCK (bin);
3789 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3791 gst_message_set_seqnum (tmessage, seqnum);
3793 /* post segment start with initial format and position. */
3794 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3796 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3800 case GST_MESSAGE_SEGMENT_DONE:
3802 gboolean post = FALSE;
3806 gst_message_parse_segment_done (message, &format, &position);
3807 seqnum = gst_message_get_seqnum (message);
3809 bin_do_message_forward (bin, message);
3811 GST_OBJECT_LOCK (bin);
3812 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3813 /* if there are no more segment_start messages, everybody posted
3814 * a segment_done and we can post one on the bus. */
3816 /* we don't care who still has a pending segment start */
3817 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3820 /* remove all old segment_done messages */
3821 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3823 GST_OBJECT_UNLOCK (bin);
3825 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3827 gst_message_set_seqnum (tmessage, seqnum);
3829 /* post segment done with latest format and position. */
3830 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3832 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3836 case GST_MESSAGE_DURATION_CHANGED:
3838 /* FIXME: remove all cached durations, next time somebody asks
3839 * for duration, we will recalculate. */
3841 GST_OBJECT_LOCK (bin);
3842 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION_CHANGED);
3843 GST_OBJECT_UNLOCK (bin);
3847 case GST_MESSAGE_CLOCK_LOST:
3849 GstClock **provided_clock_p;
3850 GstElement **clock_provider_p;
3851 gboolean playing, toplevel, provided, forward;
3854 gst_message_parse_clock_lost (message, &clock);
3856 GST_OBJECT_LOCK (bin);
3857 bin->clock_dirty = TRUE;
3858 /* if we lost the clock that we provided, post to parent but
3859 * only if we are not a top-level bin or PLAYING.
3860 * The reason for this is that applications should be able
3861 * to PAUSE/PLAY if they receive this message without worrying
3862 * about the state of the pipeline. */
3863 provided = (clock == bin->provided_clock);
3864 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3865 toplevel = GST_OBJECT_PARENT (bin) == NULL;
3866 forward = provided && (playing || !toplevel);
3868 GST_DEBUG_OBJECT (bin,
3869 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3870 bin->provided_clock, bin->clock_provider);
3871 provided_clock_p = &bin->provided_clock;
3872 clock_provider_p = &bin->clock_provider;
3873 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3874 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3876 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3877 provided, playing, forward);
3878 GST_OBJECT_UNLOCK (bin);
3884 gst_message_unref (message);
3887 case GST_MESSAGE_CLOCK_PROVIDE:
3891 GST_OBJECT_LOCK (bin);
3892 bin->clock_dirty = TRUE;
3893 /* a new clock is available, post to parent but not
3894 * to the application */
3895 forward = GST_OBJECT_PARENT (bin) != NULL;
3896 GST_OBJECT_UNLOCK (bin);
3902 gst_message_unref (message);
3905 case GST_MESSAGE_ASYNC_START:
3909 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3910 src ? GST_OBJECT_NAME (src) : "(NULL)");
3912 bin_do_message_forward (bin, message);
3914 GST_OBJECT_LOCK (bin);
3915 /* we ignore the message if we are going to <= READY */
3916 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3917 goto ignore_start_message;
3919 /* takes ownership of the message */
3920 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3922 bin_handle_async_start (bin);
3923 GST_OBJECT_UNLOCK (bin);
3926 ignore_start_message:
3928 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3929 gst_element_state_get_name (target));
3930 GST_OBJECT_UNLOCK (bin);
3931 gst_message_unref (message);
3935 case GST_MESSAGE_ASYNC_DONE:
3937 GstClockTime running_time;
3940 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3941 src ? GST_OBJECT_NAME (src) : "(NULL)");
3943 gst_message_parse_async_done (message, &running_time);
3945 bin_do_message_forward (bin, message);
3947 GST_OBJECT_LOCK (bin);
3948 /* ignore messages if we are shutting down */
3949 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3950 goto ignore_done_message;
3952 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3953 /* if there are no more ASYNC_START messages, everybody posted
3954 * a ASYNC_DONE and we can post one on the bus. When checking, we
3955 * don't care who still has a pending ASYNC_START */
3956 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3957 /* nothing found, remove all old ASYNC_DONE messages */
3958 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3960 GST_DEBUG_OBJECT (bin, "async elements committed");
3961 /* when we get an async done message when a state change was busy, we
3962 * need to set the pending_done flag so that at the end of the state
3963 * change we can see if we need to verify pending async elements, hence
3964 * the TRUE argument here. */
3965 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
3968 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3970 GST_OBJECT_UNLOCK (bin);
3973 ignore_done_message:
3975 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3976 gst_element_state_get_name (target));
3977 GST_OBJECT_UNLOCK (bin);
3978 gst_message_unref (message);
3982 case GST_MESSAGE_STRUCTURE_CHANGE:
3986 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3988 GST_OBJECT_LOCK (bin);
3990 /* while the pad is busy, avoid following it when doing state changes.
3991 * Don't update the cookie yet, we will do that after the structure
3992 * change finished and we are ready to inspect the new updated
3994 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3997 /* a pad link/unlink ended, signal the state change iterator that we
3998 * need to resync by updating the structure_cookie. */
3999 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
4000 GST_MESSAGE_STRUCTURE_CHANGE);
4001 if (!GST_BIN_IS_NO_RESYNC (bin))
4002 bin->priv->structure_cookie++;
4004 GST_OBJECT_UNLOCK (bin);
4007 gst_message_unref (message);
4011 case GST_MESSAGE_NEED_CONTEXT:{
4012 const gchar *context_type;
4013 GList *l, *contexts;
4015 gst_message_parse_context_type (message, &context_type);
4016 GST_OBJECT_LOCK (bin);
4017 contexts = GST_ELEMENT_CAST (bin)->contexts;
4018 GST_LOG_OBJECT (bin, "got need-context message type: %s", context_type);
4019 for (l = contexts; l; l = l->next) {
4020 GstContext *tmp = l->data;
4021 const gchar *tmp_type = gst_context_get_context_type (tmp);
4023 if (strcmp (context_type, tmp_type) == 0) {
4024 gst_element_set_context (GST_ELEMENT (src), l->data);
4028 GST_OBJECT_UNLOCK (bin);
4030 /* Forward if we couldn't answer the message */
4034 gst_message_unref (message);
4039 case GST_MESSAGE_HAVE_CONTEXT:{
4040 GstContext *context;
4042 gst_message_parse_have_context (message, &context);
4043 gst_bin_update_context (bin, context);
4044 gst_context_unref (context);
4056 /* Send all other messages upward */
4057 GST_DEBUG_OBJECT (bin, "posting message upward");
4058 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
4063 /* generic struct passed to all query fold methods */
4072 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
4073 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
4075 /* for duration/position we collect all durations/positions and take
4076 * the MAX of all valid results */
4078 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
4086 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
4088 gboolean res = FALSE;
4089 GstObject *item = g_value_get_object (vitem);
4090 if (GST_IS_PAD (item))
4091 res = gst_pad_query (GST_PAD (item), fold->query);
4093 res = gst_element_query (GST_ELEMENT (item), fold->query);
4098 g_value_set_boolean (ret, TRUE);
4100 gst_query_parse_duration (fold->query, NULL, &duration);
4102 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
4104 if (duration == -1) {
4105 /* duration query succeeded, but duration is unknown */
4110 if (duration > fold->max)
4111 fold->max = duration;
4118 bin_query_duration_done (GstBin * bin, QueryFold * fold)
4122 gst_query_parse_duration (fold->query, &format, NULL);
4123 /* store max in query result */
4124 gst_query_set_duration (fold->query, format, fold->max);
4126 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
4128 /* FIXME: re-implement duration caching */
4131 GST_OBJECT_LOCK (bin);
4132 bin->messages = g_list_prepend (bin->messages,
4133 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
4134 GST_OBJECT_UNLOCK (bin);
4139 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
4141 gboolean res = FALSE;
4142 GstObject *item = g_value_get_object (vitem);
4143 if (GST_IS_PAD (item))
4144 res = gst_pad_query (GST_PAD (item), fold->query);
4146 res = gst_element_query (GST_ELEMENT (item), fold->query);
4151 g_value_set_boolean (ret, TRUE);
4153 gst_query_parse_position (fold->query, NULL, &position);
4155 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
4157 if (position > fold->max)
4158 fold->max = position;
4165 bin_query_position_done (GstBin * bin, QueryFold * fold)
4169 gst_query_parse_position (fold->query, &format, NULL);
4170 /* store max in query result */
4171 gst_query_set_position (fold->query, format, fold->max);
4173 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
4177 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
4179 gboolean res = FALSE;
4180 GstObject *item = g_value_get_object (vitem);
4181 if (GST_IS_PAD (item))
4182 res = gst_pad_query (GST_PAD (item), fold->query);
4184 res = gst_element_query (GST_ELEMENT (item), fold->query);
4186 GstClockTime min, max;
4189 gst_query_parse_latency (fold->query, &live, &min, &max);
4191 GST_DEBUG_OBJECT (item,
4192 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
4193 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
4195 /* for the combined latency we collect the MAX of all min latencies and
4196 * the MIN of all max latencies */
4198 if (min > fold->min)
4200 if (fold->max == -1)
4202 else if (max < fold->max)
4208 g_value_set_boolean (ret, FALSE);
4209 GST_DEBUG_OBJECT (item, "failed query");
4216 bin_query_latency_done (GstBin * bin, QueryFold * fold)
4218 /* store max in query result */
4219 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
4221 GST_DEBUG_OBJECT (bin,
4222 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
4223 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
4227 /* generic fold, return first valid result */
4229 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
4231 gboolean res = FALSE;
4232 GstObject *item = g_value_get_object (vitem);
4233 if (GST_IS_PAD (item))
4234 res = gst_pad_query (GST_PAD (item), fold->query);
4236 res = gst_element_query (GST_ELEMENT (item), fold->query);
4238 g_value_set_boolean (ret, TRUE);
4239 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
4242 /* and stop as soon as we have a valid result */
4246 /* Perform a query iteration for the given bin. The query is stored in
4247 * QueryFold and iter should be either a GstPad iterator or a
4248 * GstElement iterator. */
4250 bin_iterate_fold (GstBin * bin, GstIterator * iter, QueryInitFunction fold_init,
4251 QueryDoneFunction fold_done, GstIteratorFoldFunction fold_func,
4252 QueryFold * fold_data, gboolean default_return)
4254 gboolean res = default_return;
4256 /* set the result of the query to FALSE initially */
4257 g_value_init (&ret, G_TYPE_BOOLEAN);
4258 g_value_set_boolean (&ret, res);
4261 GstIteratorResult ires;
4263 ires = gst_iterator_fold (iter, fold_func, &ret, fold_data);
4266 case GST_ITERATOR_RESYNC:
4267 gst_iterator_resync (iter);
4269 fold_init (bin, fold_data);
4270 g_value_set_boolean (&ret, res);
4272 case GST_ITERATOR_OK:
4273 case GST_ITERATOR_DONE:
4274 res = g_value_get_boolean (&ret);
4275 if (fold_done != NULL && res)
4276 fold_done (bin, fold_data);
4288 gst_bin_query (GstElement * element, GstQuery * query)
4290 GstBin *bin = GST_BIN_CAST (element);
4292 gboolean default_return = FALSE;
4293 gboolean res = FALSE;
4294 gboolean src_pads_query_result = FALSE;
4295 GstIteratorFoldFunction fold_func;
4296 QueryInitFunction fold_init = NULL;
4297 QueryDoneFunction fold_done = NULL;
4298 QueryFold fold_data;
4300 switch (GST_QUERY_TYPE (query)) {
4301 case GST_QUERY_DURATION:
4303 /* FIXME: implement duration caching in GstBin again */
4308 gst_query_parse_duration (query, &qformat, NULL);
4310 /* find cached duration query */
4311 GST_OBJECT_LOCK (bin);
4312 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
4313 GstMessage *message = (GstMessage *) cached->data;
4315 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION_CHANGED &&
4316 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
4320 gst_message_parse_duration (message, &format, &duration);
4322 /* if cached same format, copy duration in query result */
4323 if (format == qformat) {
4324 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
4326 GST_OBJECT_UNLOCK (bin);
4328 gst_query_set_duration (query, qformat, duration);
4334 GST_OBJECT_UNLOCK (bin);
4336 #ifndef GST_DISABLE_GST_DEBUG
4338 /* Quieten this particularly annoying FIXME a bit: */
4339 static gboolean printed_fixme = FALSE;
4340 if (!printed_fixme) {
4341 GST_FIXME ("implement duration caching in GstBin again");
4342 printed_fixme = TRUE;
4348 /* no cached value found, iterate and collect durations */
4349 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
4350 fold_init = bin_query_min_max_init;
4351 fold_done = bin_query_duration_done;
4354 case GST_QUERY_POSITION:
4356 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
4357 fold_init = bin_query_min_max_init;
4358 fold_done = bin_query_position_done;
4361 case GST_QUERY_LATENCY:
4363 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
4364 fold_init = bin_query_min_max_init;
4365 fold_done = bin_query_latency_done;
4366 default_return = TRUE;
4370 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
4374 fold_data.query = query;
4376 iter = gst_bin_iterate_sinks (bin);
4377 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
4378 query, GST_QUERY_TYPE_NAME (query));
4381 fold_init (bin, &fold_data);
4384 bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func, &fold_data,
4386 gst_iterator_free (iter);
4389 /* Query the source pads of the element */
4390 iter = gst_element_iterate_src_pads (element);
4391 src_pads_query_result =
4392 bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func,
4393 &fold_data, default_return);
4394 gst_iterator_free (iter);
4396 if (src_pads_query_result)
4400 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
4406 set_context (const GValue * item, gpointer user_data)
4408 GstElement *element = g_value_get_object (item);
4410 gst_element_set_context (element, user_data);
4414 gst_bin_set_context (GstElement * element, GstContext * context)
4417 GstIterator *children;
4419 g_return_if_fail (GST_IS_BIN (element));
4421 bin = GST_BIN (element);
4423 GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
4425 children = gst_bin_iterate_elements (bin);
4426 while (gst_iterator_foreach (children, set_context,
4427 context) == GST_ITERATOR_RESYNC)
4428 gst_iterator_resync (children);
4429 gst_iterator_free (children);
4433 compare_name (const GValue * velement, const gchar * name)
4436 GstElement *element = g_value_get_object (velement);
4438 GST_OBJECT_LOCK (element);
4439 eq = strcmp (GST_ELEMENT_NAME (element), name);
4440 GST_OBJECT_UNLOCK (element);
4446 * gst_bin_get_by_name:
4448 * @name: the element name to search for
4450 * Gets the element with the given name from a bin. This
4451 * function recurses into child bins.
4453 * Returns %NULL if no element with the given name is found in the bin.
4455 * MT safe. Caller owns returned reference.
4457 * Returns: (transfer full) (nullable): the #GstElement with the given
4461 gst_bin_get_by_name (GstBin * bin, const gchar * name)
4463 GstIterator *children;
4464 GValue result = { 0, };
4465 GstElement *element;
4468 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4470 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
4471 GST_ELEMENT_NAME (bin), name);
4473 children = gst_bin_iterate_recurse (bin);
4474 found = gst_iterator_find_custom (children,
4475 (GCompareFunc) compare_name, &result, (gpointer) name);
4476 gst_iterator_free (children);
4479 element = g_value_dup_object (&result);
4480 g_value_unset (&result);
4489 * gst_bin_get_by_name_recurse_up:
4491 * @name: the element name to search for
4493 * Gets the element with the given name from this bin. If the
4494 * element is not found, a recursion is performed on the parent bin.
4497 * - no element with the given name is found in the bin
4499 * MT safe. Caller owns returned reference.
4501 * Returns: (transfer full) (nullable): the #GstElement with the given
4505 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
4509 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4510 g_return_val_if_fail (name != NULL, NULL);
4512 result = gst_bin_get_by_name (bin, name);
4517 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
4519 if (GST_IS_BIN (parent)) {
4520 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
4522 gst_object_unref (parent);
4530 compare_interface (const GValue * velement, GValue * interface)
4532 GstElement *element = g_value_get_object (velement);
4533 GType interface_type = (GType) g_value_get_pointer (interface);
4536 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
4545 * gst_bin_get_by_interface:
4547 * @iface: the #GType of an interface
4549 * Looks for an element inside the bin that implements the given
4550 * interface. If such an element is found, it returns the element.
4551 * You can cast this element to the given interface afterwards. If you want
4552 * all elements that implement the interface, use
4553 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
4555 * MT safe. Caller owns returned reference.
4557 * Returns: (transfer full) (nullable): A #GstElement inside the bin
4558 * implementing the interface
4561 gst_bin_get_by_interface (GstBin * bin, GType iface)
4563 GstIterator *children;
4564 GValue result = { 0, };
4565 GstElement *element;
4567 GValue viface = { 0, };
4569 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4570 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4572 g_value_init (&viface, G_TYPE_POINTER);
4573 g_value_set_pointer (&viface, (gpointer) iface);
4575 children = gst_bin_iterate_recurse (bin);
4576 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
4578 gst_iterator_free (children);
4581 element = g_value_dup_object (&result);
4582 g_value_unset (&result);
4586 g_value_unset (&viface);
4592 * gst_bin_iterate_all_by_interface:
4594 * @iface: the #GType of an interface
4596 * Looks for all elements inside the bin that implements the given
4597 * interface. You can safely cast all returned elements to the given interface.
4598 * The function recurses inside child bins. The iterator will yield a series
4599 * of #GstElement that should be unreffed after use.
4601 * MT safe. Caller owns returned value.
4603 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement
4604 * for all elements in the bin implementing the given interface,
4608 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
4610 GstIterator *children;
4611 GstIterator *result;
4612 GValue viface = { 0, };
4614 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4615 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4617 g_value_init (&viface, G_TYPE_POINTER);
4618 g_value_set_pointer (&viface, (gpointer) iface);
4620 children = gst_bin_iterate_recurse (bin);
4621 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
4624 g_value_unset (&viface);