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.
28 * @short_description: Base class and element that can contain other elements
30 * #GstBin is an element that can contain other #GstElement, allowing them to be
32 * Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
33 * This makes the bin look like any other elements and enables creation of
34 * higher-level abstraction elements.
36 * A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
37 * want to create a toplevel bin because a normal bin doesn't have a bus or
38 * handle clock distribution of its own.
40 * After the bin has been created you will typically add elements to it with
41 * gst_bin_add(). You can remove elements with gst_bin_remove().
43 * An element can be retrieved from a bin with gst_bin_get_by_name(), using the
44 * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
45 * purposes and will query the parent bins when the element is not found in the
48 * An iterator of elements in a bin can be retrieved with
49 * gst_bin_iterate_elements(). Various other iterators exist to retrieve the
52 * gst_object_unref() is used to drop your reference to the bin.
54 * The #GstBin::element-added signal is fired whenever a new element is added to
55 * the bin. Likewise the #GstBin::element-removed signal is fired whenever an
56 * element is removed from the bin.
58 * <refsect2><title>Notes</title>
60 * A #GstBin internally intercepts every #GstMessage posted by its children and
61 * implements the following default behaviour for each of them:
64 * <term>GST_MESSAGE_EOS</term>
65 * <listitem><para>This message is only posted by sinks in the PLAYING
66 * state. If all sinks posted the EOS message, this bin will post and EOS
67 * message upwards.</para></listitem>
70 * <term>GST_MESSAGE_SEGMENT_START</term>
71 * <listitem><para>just collected and never forwarded upwards.
72 * The messages are used to decide when all elements have completed playback
73 * of their segment.</para></listitem>
76 * <term>GST_MESSAGE_SEGMENT_DONE</term>
77 * <listitem><para> Is posted by #GstBin when all elements that posted
78 * a SEGMENT_START have posted a SEGMENT_DONE.</para></listitem>
81 * <term>GST_MESSAGE_DURATION_CHANGED</term>
82 * <listitem><para> Is posted by an element that detected a change
83 * in the stream duration. The default bin behaviour is to clear any
84 * cached duration values so that the next duration query will perform
85 * a full duration recalculation. The duration change is posted to the
86 * application so that it can refetch the new duration with a duration
87 * query. Note that these messages can be posted before the bin is
88 * prerolled, in which case the duration query might fail.
92 * <term>GST_MESSAGE_CLOCK_LOST</term>
93 * <listitem><para> This message is posted by an element when it
94 * can no longer provide a clock. The default bin behaviour is to
95 * check if the lost clock was the one provided by the bin. If so and
96 * the bin is currently in the PLAYING state, the message is forwarded to
98 * This message is also generated when a clock provider is removed from
99 * the bin. If this message is received by the application, it should
100 * PAUSE the pipeline and set it back to PLAYING to force a new clock
105 * <term>GST_MESSAGE_CLOCK_PROVIDE</term>
106 * <listitem><para> This message is generated when an element
107 * can provide a clock. This mostly happens when a new clock
108 * provider is added to the bin. The default behaviour of the bin is to
109 * mark the currently selected clock as dirty, which will perform a clock
110 * recalculation the next time the bin is asked to provide a clock.
111 * This message is never sent tot the application but is forwarded to
112 * the parent of the bin.
116 * <term>OTHERS</term>
117 * <listitem><para> posted upwards.</para></listitem>
122 * A #GstBin implements the following default behaviour for answering to a
126 * <term>GST_QUERY_DURATION</term>
127 * <listitem><para>If the query has been asked before with the same format
128 * and the bin is a toplevel bin (ie. has no parent),
129 * use the cached previous value. If no previous value was cached, the
130 * query is sent to all sink elements in the bin and the MAXIMUM of all
131 * values is returned. If the bin is a toplevel bin the value is cached.
132 * If no sinks are available in the bin, the query fails.
136 * <term>GST_QUERY_POSITION</term>
137 * <listitem><para>The query is sent to all sink elements in the bin and the
138 * MAXIMUM of all values is returned. If no sinks are available in the bin,
143 * <term>OTHERS</term>
144 * <listitem><para>the query is forwarded to all sink elements, the result
145 * of the first sink that answers the query successfully is returned. If no
146 * sink is in the bin, the query fails.</para></listitem>
150 * A #GstBin will by default forward any event sent to it to all sink elements.
151 * If all the sinks return %TRUE, the bin will also return %TRUE, else %FALSE is
152 * returned. If no sinks are in the bin, the event handler will return %TRUE.
158 #include "gst_private.h"
160 #include "gstevent.h"
163 #include "gsterror.h"
165 #include "gstutils.h"
166 #include "gstchildproxy.h"
168 GST_DEBUG_CATEGORY_STATIC (bin_debug);
169 #define GST_CAT_DEFAULT bin_debug
171 /* a bin is toplevel if it has no parent or when it is configured to behave like
173 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
175 #define GST_BIN_GET_PRIVATE(obj) \
176 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
178 struct _GstBinPrivate
180 gboolean asynchandling;
181 /* if we get an ASYNC_DONE message from ourselves, this means that the
182 * subclass will simulate ASYNC behaviour without having ASYNC children. When
183 * such an ASYNC_DONE message is posted while we are doing a state change, we
184 * have to process the message after finishing the state change even when no
185 * child returned GST_STATE_CHANGE_ASYNC. */
186 gboolean pending_async_done;
188 guint32 structure_cookie;
195 /* forward messages from our children */
196 gboolean message_forward;
199 gboolean posted_playing;
211 static void gst_bin_dispose (GObject * object);
213 static void gst_bin_set_property (GObject * object, guint prop_id,
214 const GValue * value, GParamSpec * pspec);
215 static void gst_bin_get_property (GObject * object, guint prop_id,
216 GValue * value, GParamSpec * pspec);
218 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
219 GstStateChange transition);
220 static gboolean gst_bin_post_message (GstElement * element, GstMessage * msg);
221 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
222 GstState * state, GstState * pending, GstClockTime timeout);
223 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
224 gboolean flag_pending, GstClockTime running_time);
225 static void bin_handle_async_start (GstBin * bin);
226 static void bin_push_state_continue (BinContinueData * data);
227 static void bin_do_eos (GstBin * bin);
229 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
230 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
233 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
234 static GstIndex *gst_bin_get_index_func (GstElement * element);
237 static GstClock *gst_bin_provide_clock_func (GstElement * element);
238 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
240 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
241 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
242 static GstBusSyncReply bin_bus_handler (GstBus * bus,
243 GstMessage * message, GstBin * bin);
244 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
245 static void gst_bin_set_context (GstElement * element, GstContext * context);
247 static gboolean gst_bin_do_latency_func (GstBin * bin);
249 static void bin_remove_messages (GstBin * bin, GstObject * src,
250 GstMessageType types);
251 static void gst_bin_continue_func (BinContinueData * data);
252 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
253 static gint bin_element_is_src (GstElement * child, GstBin * bin);
255 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
257 /* Bin signals and properties */
266 #define DEFAULT_ASYNC_HANDLING FALSE
267 #define DEFAULT_MESSAGE_FORWARD FALSE
273 PROP_MESSAGE_FORWARD,
277 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
279 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
283 static const GInterfaceInfo iface_info = { \
284 gst_bin_child_proxy_init, \
288 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
290 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
291 "debugging info for the 'bin' container element"); \
295 #define gst_bin_parent_class parent_class
296 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
299 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
305 bin = GST_BIN_CAST (child_proxy);
307 GST_OBJECT_LOCK (bin);
308 if ((res = g_list_nth_data (bin->children, index)))
309 gst_object_ref (res);
310 GST_OBJECT_UNLOCK (bin);
312 return (GObject *) res;
316 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
321 bin = GST_BIN_CAST (child_proxy);
323 GST_OBJECT_LOCK (bin);
324 num = bin->numchildren;
325 GST_OBJECT_UNLOCK (bin);
331 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
333 GstChildProxyInterface *iface = g_iface;
335 iface->get_children_count = gst_bin_child_proxy_get_children_count;
336 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
340 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
341 GValue * return_accu, const GValue * handler_return, gpointer dummy)
345 myboolean = g_value_get_boolean (handler_return);
346 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
347 g_value_set_boolean (return_accu, myboolean);
349 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
356 gst_bin_class_init (GstBinClass * klass)
358 GObjectClass *gobject_class;
359 GstElementClass *gstelement_class;
362 gobject_class = (GObjectClass *) klass;
363 gstelement_class = (GstElementClass *) klass;
365 g_type_class_add_private (klass, sizeof (GstBinPrivate));
367 gobject_class->set_property = gst_bin_set_property;
368 gobject_class->get_property = gst_bin_get_property;
371 * GstBin:async-handling:
373 * If set to %TRUE, the bin will handle asynchronous state changes.
374 * This should be used only if the bin subclass is modifying the state
375 * of its children on its own.
377 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
378 g_param_spec_boolean ("async-handling", "Async Handling",
379 "The bin will handle Asynchronous state changes",
380 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
383 * GstBin::element-added:
385 * @element: the #GstElement that was added to the bin
387 * Will be emitted after the element was added to the bin.
389 gst_bin_signals[ELEMENT_ADDED] =
390 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
391 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
392 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
394 * GstBin::element-removed:
396 * @element: the #GstElement that was removed from the bin
398 * Will be emitted after the element was removed from the bin.
400 gst_bin_signals[ELEMENT_REMOVED] =
401 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
402 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
403 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
405 * GstBin::do-latency:
408 * Will be emitted when the bin needs to perform latency calculations. This
409 * signal is only emitted for toplevel bins or when async-handling is
412 * Only one signal handler is invoked. If no signals are connected, the
413 * default handler is invoked, which will query and distribute the lowest
414 * possible latency to all sinks.
416 * Connect to this signal if the default latency calculations are not
417 * sufficient, like when you need different latencies for different sinks in
420 gst_bin_signals[DO_LATENCY] =
421 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
422 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
423 _gst_boolean_accumulator, NULL, g_cclosure_marshal_generic,
424 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
427 * GstBin:message-forward:
429 * Forward all children messages, even those that would normally be filtered by
430 * the bin. This can be interesting when one wants to be notified of the EOS
431 * state of individual elements, for example.
433 * The messages are converted to an ELEMENT message with the bin as the
434 * source. The structure of the message is named 'GstBinForwarded' and contains
435 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
438 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
439 g_param_spec_boolean ("message-forward", "Message Forward",
440 "Forwards all children messages",
441 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
443 gobject_class->dispose = gst_bin_dispose;
445 gst_element_class_set_static_metadata (gstelement_class, "Generic bin",
447 "Simple container object",
448 "Erik Walthinsen <omega@cse.ogi.edu>,"
449 "Wim Taymans <wim.taymans@gmail.com>");
451 gstelement_class->change_state =
452 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
453 gstelement_class->post_message = GST_DEBUG_FUNCPTR (gst_bin_post_message);
454 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
456 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
457 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
459 gstelement_class->provide_clock =
460 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
461 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
463 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
464 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
465 gstelement_class->set_context = GST_DEBUG_FUNCPTR (gst_bin_set_context);
467 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
468 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
469 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
471 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
473 GST_DEBUG ("creating bin thread pool");
476 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
478 g_critical ("could alloc threadpool %s", err->message);
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 bin->child_bus = bus;
497 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
499 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin,
502 bin->priv = GST_BIN_GET_PRIVATE (bin);
503 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
504 bin->priv->structure_cookie = 0;
505 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
509 gst_bin_dispose (GObject * object)
511 GstBin *bin = GST_BIN_CAST (object);
512 GstBus **child_bus_p = &bin->child_bus;
513 GstClock **provided_clock_p = &bin->provided_clock;
514 GstElement **clock_provider_p = &bin->clock_provider;
516 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
518 GST_OBJECT_LOCK (object);
519 gst_object_replace ((GstObject **) child_bus_p, NULL);
520 gst_object_replace ((GstObject **) provided_clock_p, NULL);
521 gst_object_replace ((GstObject **) clock_provider_p, NULL);
522 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
523 GST_OBJECT_UNLOCK (object);
525 while (bin->children) {
526 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
528 if (G_UNLIKELY (bin->children != NULL)) {
529 g_critical ("could not remove elements from bin '%s'",
530 GST_STR_NULL (GST_OBJECT_NAME (object)));
533 g_list_free_full (bin->priv->contexts, (GDestroyNotify) gst_context_unref);
535 G_OBJECT_CLASS (parent_class)->dispose (object);
540 * @name: (allow-none): the name of the new bin
542 * Creates a new bin with the given name.
544 * Returns: (transfer floating): a new #GstBin
547 gst_bin_new (const gchar * name)
549 return gst_element_factory_make ("bin", name);
553 gst_bin_set_property (GObject * object, guint prop_id,
554 const GValue * value, GParamSpec * pspec)
558 gstbin = GST_BIN_CAST (object);
561 case PROP_ASYNC_HANDLING:
562 GST_OBJECT_LOCK (gstbin);
563 gstbin->priv->asynchandling = g_value_get_boolean (value);
564 GST_OBJECT_UNLOCK (gstbin);
566 case PROP_MESSAGE_FORWARD:
567 GST_OBJECT_LOCK (gstbin);
568 gstbin->priv->message_forward = g_value_get_boolean (value);
569 GST_OBJECT_UNLOCK (gstbin);
572 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
578 gst_bin_get_property (GObject * object, guint prop_id,
579 GValue * value, GParamSpec * pspec)
583 gstbin = GST_BIN_CAST (object);
586 case PROP_ASYNC_HANDLING:
587 GST_OBJECT_LOCK (gstbin);
588 g_value_set_boolean (value, gstbin->priv->asynchandling);
589 GST_OBJECT_UNLOCK (gstbin);
591 case PROP_MESSAGE_FORWARD:
592 GST_OBJECT_LOCK (gstbin);
593 g_value_set_boolean (value, gstbin->priv->message_forward);
594 GST_OBJECT_UNLOCK (gstbin);
597 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
603 /* return the cached index */
605 gst_bin_get_index_func (GstElement * element)
610 bin = GST_BIN_CAST (element);
612 GST_OBJECT_LOCK (bin);
613 if ((result = bin->priv->index))
614 gst_object_ref (result);
615 GST_OBJECT_UNLOCK (bin);
620 /* set the index on all elements in this bin
625 gst_bin_set_index_func (GstElement * element, GstIndex * index)
631 GValue data = { 0, };
633 bin = GST_BIN_CAST (element);
635 GST_OBJECT_LOCK (bin);
636 old = bin->priv->index;
637 if (G_UNLIKELY (old == index))
640 gst_object_ref (index);
641 bin->priv->index = index;
642 GST_OBJECT_UNLOCK (bin);
645 gst_object_unref (old);
647 it = gst_bin_iterate_elements (bin);
649 /* set the index on all elements in the bin */
652 switch (gst_iterator_next (it, &data)) {
653 case GST_ITERATOR_OK:
655 GstElement *child = g_value_get_object (&data);
657 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
658 GST_ELEMENT_NAME (child));
659 gst_element_set_index (child, index);
661 g_value_reset (&data);
664 case GST_ITERATOR_RESYNC:
665 GST_DEBUG_OBJECT (bin, "iterator doing resync");
666 gst_iterator_resync (it);
669 case GST_ITERATOR_DONE:
670 GST_DEBUG_OBJECT (bin, "iterator done");
675 g_value_unset (&data);
676 gst_iterator_free (it);
681 GST_DEBUG_OBJECT (bin, "index was already set");
682 GST_OBJECT_UNLOCK (bin);
688 /* set the clock on all elements in this bin
693 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
699 GValue data = { 0, };
701 bin = GST_BIN_CAST (element);
703 it = gst_bin_iterate_elements (bin);
707 switch (gst_iterator_next (it, &data)) {
708 case GST_ITERATOR_OK:
710 GstElement *child = g_value_get_object (&data);
712 res &= gst_element_set_clock (child, clock);
714 g_value_reset (&data);
717 case GST_ITERATOR_RESYNC:
718 GST_DEBUG_OBJECT (bin, "iterator doing resync");
719 gst_iterator_resync (it);
723 case GST_ITERATOR_DONE:
724 GST_DEBUG_OBJECT (bin, "iterator done");
729 g_value_unset (&data);
730 gst_iterator_free (it);
733 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
738 /* get the clock for this bin by asking all of the children in this bin
740 * The ref of the returned clock in increased so unref after usage.
742 * We loop the elements in state order and pick the last clock we can
743 * get. This makes sure we get a clock from the source.
748 gst_bin_provide_clock_func (GstElement * element)
750 GstClock *result = NULL;
751 GstElement *provider = NULL;
756 GstClock **provided_clock_p;
757 GstElement **clock_provider_p;
759 bin = GST_BIN_CAST (element);
761 GST_OBJECT_LOCK (bin);
762 if (!bin->clock_dirty)
765 GST_DEBUG_OBJECT (bin, "finding new clock");
767 it = gst_bin_sort_iterator_new (bin);
768 GST_OBJECT_UNLOCK (bin);
772 switch (gst_iterator_next (it, &val)) {
773 case GST_ITERATOR_OK:
775 GstElement *child = g_value_get_object (&val);
778 clock = gst_element_provide_clock (child);
780 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
781 clock, GST_ELEMENT_NAME (child));
783 gst_object_unref (result);
784 gst_object_unref (provider);
787 provider = gst_object_ref (child);
790 g_value_reset (&val);
793 case GST_ITERATOR_RESYNC:
794 gst_iterator_resync (it);
797 case GST_ITERATOR_DONE:
802 g_value_unset (&val);
803 gst_iterator_free (it);
805 GST_OBJECT_LOCK (bin);
806 if (!bin->clock_dirty) {
808 gst_object_unref (provider);
810 gst_object_unref (result);
816 provided_clock_p = &bin->provided_clock;
817 clock_provider_p = &bin->clock_provider;
818 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
819 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
820 bin->clock_dirty = FALSE;
821 GST_DEBUG_OBJECT (bin,
822 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
824 /* Provider is not being returned to caller, just the result */
826 gst_object_unref (provider);
827 GST_OBJECT_UNLOCK (bin);
833 if ((result = bin->provided_clock))
834 gst_object_ref (result);
835 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
836 GST_OBJECT_UNLOCK (bin);
843 * functions for manipulating cached messages
848 GstMessageType types;
851 /* check if a message is of given src and type */
853 message_check (GstMessage * message, MessageFind * target)
858 eq &= GST_MESSAGE_SRC (message) == target->src;
860 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
861 GST_LOG ("looking at message %p: %d", message, eq);
867 find_message (GstBin * bin, GstObject * src, GstMessageType types)
875 result = g_list_find_custom (bin->messages, &find,
876 (GCompareFunc) message_check);
879 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
880 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
883 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
884 #ifndef GST_DISABLE_GST_DEBUG
888 for (i = 0; i < 32; i++)
889 if (types & (1U << i))
890 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1U << i));
898 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
901 * A message that is cached and has the same SRC and type is replaced
902 * by the given message.
905 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
911 if ((src = GST_MESSAGE_SRC (message))) {
912 /* first find the previous message posted by this element */
913 if ((previous = find_message (bin, src, types))) {
914 GstMessage *previous_msg;
916 /* if we found a previous message, replace it */
917 previous_msg = previous->data;
918 previous->data = message;
920 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
921 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
922 GST_MESSAGE_TYPE_NAME (message));
924 gst_message_unref (previous_msg);
926 /* keep new message */
927 bin->messages = g_list_prepend (bin->messages, message);
929 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
930 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
933 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
934 GST_MESSAGE_TYPE_NAME (message));
936 gst_message_unref (message);
941 /* with LOCK. Remove all messages of given types */
943 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
951 for (walk = bin->messages; walk; walk = next) {
952 GstMessage *message = (GstMessage *) walk->data;
954 next = g_list_next (walk);
956 if (message_check (message, &find) == 0) {
957 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
958 "deleting message %p of types 0x%08x", 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);
1087 /* vmethod that adds an element to a bin
1092 gst_bin_add_func (GstBin * bin, GstElement * element)
1096 gboolean is_sink, is_source, provides_clock, requires_clock;
1097 GstMessage *clock_message = NULL, *async_message = NULL;
1098 GstStateChangeReturn ret;
1101 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1103 /* we obviously can't add ourself to ourself */
1104 if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
1107 /* get the element name to make sure it is unique in this bin. */
1108 GST_OBJECT_LOCK (element);
1109 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1110 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1111 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1113 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1115 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1116 GST_OBJECT_UNLOCK (element);
1118 GST_OBJECT_LOCK (bin);
1120 /* then check to see if the element's name is already taken in the bin,
1121 * we can safely take the lock here. This check is probably bogus because
1122 * you can safely change the element name after this check and before setting
1123 * the object parent. The window is very small though... */
1124 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1125 goto duplicate_name;
1127 /* set the element's parent and add the element to the bin's list of children */
1128 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1129 GST_OBJECT_CAST (bin))))
1132 /* if we add a sink we become a sink */
1134 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1136 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1139 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1141 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1143 if (provides_clock) {
1144 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1146 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1147 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1149 if (requires_clock) {
1150 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1151 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1154 bin->children = g_list_prepend (bin->children, element);
1156 bin->children_cookie++;
1157 if (!GST_BIN_IS_NO_RESYNC (bin))
1158 bin->priv->structure_cookie++;
1160 /* distribute the bus */
1161 gst_element_set_bus (element, bin->child_bus);
1163 /* propagate the current base_time, start_time and clock */
1164 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1165 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1166 /* it's possible that the element did not accept the clock but
1167 * that is not important right now. When the pipeline goes to PLAYING,
1168 * a new clock will be selected */
1169 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1171 for (l = bin->priv->contexts; l; l = l->next)
1172 gst_element_set_context (element, l->data);
1175 /* set the cached index on the children */
1176 if (bin->priv->index)
1177 gst_element_set_index (element, bin->priv->index);
1180 ret = GST_STATE_RETURN (bin);
1181 /* no need to update the state if we are in error */
1182 if (ret == GST_STATE_CHANGE_FAILURE)
1183 goto no_state_recalc;
1185 /* update the bin state, the new element could have been an ASYNC or
1186 * NO_PREROLL element */
1187 ret = GST_STATE_RETURN (element);
1188 GST_DEBUG_OBJECT (bin, "added %s element",
1189 gst_element_state_change_return_get_name (ret));
1192 case GST_STATE_CHANGE_ASYNC:
1194 /* create message to track this aync element when it posts an async-done
1196 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1199 case GST_STATE_CHANGE_NO_PREROLL:
1200 /* ignore all async elements we might have and commit our state */
1201 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1203 case GST_STATE_CHANGE_FAILURE:
1210 GST_OBJECT_UNLOCK (bin);
1212 /* post the messages on the bus of the element so that the bin can handle
1215 gst_element_post_message (element, clock_message);
1218 gst_element_post_message (element, async_message);
1220 /* unlink all linked pads */
1221 it = gst_element_iterate_pads (element);
1222 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1223 gst_iterator_free (it);
1225 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1228 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1229 gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
1236 /* ERROR handling here */
1239 GST_OBJECT_LOCK (bin);
1240 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1241 GST_OBJECT_UNLOCK (bin);
1246 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1247 elem_name, GST_ELEMENT_NAME (bin));
1248 GST_OBJECT_UNLOCK (bin);
1254 g_warning ("Element '%s' already has parent", elem_name);
1255 GST_OBJECT_UNLOCK (bin);
1264 * @element: (transfer full): the #GstElement to add
1266 * Adds the given element to the bin. Sets the element's parent, and thus
1267 * takes ownership of the element. An element can only be added to one bin.
1269 * If the element's pads are linked to other pads, the pads will be unlinked
1270 * before the element is added to the bin.
1273 * When you add an element to an already-running pipeline, you will have to
1274 * take care to set the state of the newly-added element to the desired
1275 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1276 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1277 * The bin or pipeline will not take care of this for you.
1282 * Returns: %TRUE if the element could be added, %FALSE if
1283 * the bin does not want to accept the element.
1286 gst_bin_add (GstBin * bin, GstElement * element)
1288 GstBinClass *bclass;
1291 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1292 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1294 bclass = GST_BIN_GET_CLASS (bin);
1296 if (G_UNLIKELY (bclass->add_element == NULL))
1299 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1300 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1301 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1303 result = bclass->add_element (bin, element);
1307 /* ERROR handling */
1310 g_warning ("adding elements to bin '%s' is not supported",
1311 GST_ELEMENT_NAME (bin));
1316 /* remove an element from the bin
1321 gst_bin_remove_func (GstBin * bin, GstElement * element)
1325 gboolean is_sink, is_source, provides_clock, requires_clock;
1326 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1327 GstMessage *clock_message = NULL;
1328 GstClock **provided_clock_p;
1329 GstElement **clock_provider_p;
1331 gboolean other_async, this_async, have_no_preroll;
1332 GstStateChangeReturn ret;
1334 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1336 GST_OBJECT_LOCK (bin);
1338 GST_OBJECT_LOCK (element);
1339 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1341 if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
1344 /* remove the parent ref */
1345 GST_OBJECT_PARENT (element) = NULL;
1347 /* grab element name so we can print it */
1348 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1349 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1351 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1353 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1354 GST_OBJECT_UNLOCK (element);
1358 othersource = FALSE;
1359 otherprovider = FALSE;
1360 otherrequirer = FALSE;
1361 have_no_preroll = FALSE;
1362 /* iterate the elements, we collect which ones are async and no_preroll. We
1363 * also remove the element when we find it. */
1364 for (walk = bin->children; walk; walk = next) {
1365 GstElement *child = GST_ELEMENT_CAST (walk->data);
1367 next = g_list_next (walk);
1369 if (child == element) {
1371 /* remove the element */
1372 bin->children = g_list_delete_link (bin->children, walk);
1374 gboolean child_sink, child_source, child_provider, child_requirer;
1376 GST_OBJECT_LOCK (child);
1377 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1378 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1380 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1382 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1383 /* when we remove a sink, check if there are other sinks. */
1384 if (is_sink && !othersink && child_sink)
1386 if (is_source && !othersource && child_source)
1388 if (provides_clock && !otherprovider && child_provider)
1389 otherprovider = TRUE;
1390 if (requires_clock && !otherrequirer && child_requirer)
1391 otherrequirer = TRUE;
1392 /* check if we have NO_PREROLL children */
1393 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1394 have_no_preroll = TRUE;
1395 GST_OBJECT_UNLOCK (child);
1399 /* the element must have been in the bin's list of children */
1400 if (G_UNLIKELY (!found))
1403 /* we now removed the element from the list of elements, increment the cookie
1404 * so that others can detect a change in the children list. */
1406 bin->children_cookie++;
1407 if (!GST_BIN_IS_NO_RESYNC (bin))
1408 bin->priv->structure_cookie++;
1410 if (is_sink && !othersink) {
1411 /* we're not a sink anymore */
1412 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1413 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1415 if (is_source && !othersource) {
1416 /* we're not a source anymore */
1417 GST_DEBUG_OBJECT (bin, "we removed the last source");
1418 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1420 if (provides_clock && !otherprovider) {
1421 /* we're not a clock provider anymore */
1422 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1423 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1425 if (requires_clock && !otherrequirer) {
1426 /* we're not a clock requirer anymore */
1427 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1428 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1431 /* if the clock provider for this element is removed, we lost
1432 * the clock as well, we need to inform the parent of this
1433 * so that it can select a new clock */
1434 if (bin->clock_provider == element) {
1435 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1436 bin->clock_dirty = TRUE;
1438 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1439 provided_clock_p = &bin->provided_clock;
1440 clock_provider_p = &bin->clock_provider;
1441 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1442 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1445 /* remove messages for the element, if there was a pending ASYNC_START
1446 * message we must see if removing the element caused the bin to lose its
1449 other_async = FALSE;
1450 for (walk = bin->messages; walk; walk = next) {
1451 GstMessage *message = (GstMessage *) walk->data;
1452 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1455 next = g_list_next (walk);
1458 switch (GST_MESSAGE_TYPE (message)) {
1459 case GST_MESSAGE_ASYNC_START:
1465 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1467 case GST_MESSAGE_STRUCTURE_CHANGE:
1471 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1473 /* it's unlikely that this message is still in the list of messages
1474 * because this would mean that a link/unlink is busy in another thread
1475 * while we remove the element. We still have to remove the message
1476 * because we might not receive the done message anymore when the element
1477 * is removed from the bin. */
1478 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1479 if (owner == element)
1490 /* delete all message types */
1491 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1492 message, elem_name);
1493 bin->messages = g_list_delete_link (bin->messages, walk);
1494 gst_message_unref (message);
1498 /* get last return */
1499 ret = GST_STATE_RETURN (bin);
1501 /* no need to update the state if we are in error */
1502 if (ret == GST_STATE_CHANGE_FAILURE)
1503 goto no_state_recalc;
1505 if (!other_async && this_async) {
1506 /* all other elements were not async and we removed the async one,
1507 * handle the async-done case because we are not async anymore now. */
1508 GST_DEBUG_OBJECT (bin,
1509 "we removed the last async element, have no_preroll %d",
1512 /* the current state return of the bin depends on if there are no_preroll
1513 * elements in the pipeline or not */
1514 if (have_no_preroll)
1515 ret = GST_STATE_CHANGE_NO_PREROLL;
1517 ret = GST_STATE_CHANGE_SUCCESS;
1519 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1521 GST_DEBUG_OBJECT (bin,
1522 "recalc state preroll: %d, other async: %d, this async %d",
1523 have_no_preroll, other_async, this_async);
1525 if (have_no_preroll) {
1526 ret = GST_STATE_CHANGE_NO_PREROLL;
1527 } else if (other_async) {
1528 /* there are other async elements and we were not doing an async state
1529 * change, change our pending state and go async */
1530 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1531 GST_STATE_NEXT (bin) = GST_STATE (bin);
1532 GST_STATE_PENDING (bin) = GST_STATE (bin);
1534 ret = GST_STATE_CHANGE_ASYNC;
1536 GST_STATE_RETURN (bin) = ret;
1540 gst_element_set_bus (element, NULL);
1541 /* Clear the clock we provided to the element */
1542 gst_element_set_clock (element, NULL);
1543 GST_OBJECT_UNLOCK (bin);
1546 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1548 /* unlink all linked pads */
1549 it = gst_element_iterate_pads (element);
1550 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1551 gst_iterator_free (it);
1553 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1556 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1557 gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
1561 /* element is really out of our control now */
1562 gst_object_unref (element);
1566 /* ERROR handling */
1569 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1570 GST_ELEMENT_NAME (bin));
1571 GST_OBJECT_UNLOCK (element);
1572 GST_OBJECT_UNLOCK (bin);
1581 * @element: (transfer none): the #GstElement to remove
1583 * Removes the element from the bin, unparenting it as well.
1584 * Unparenting the element means that the element will be dereferenced,
1585 * so if the bin holds the only reference to the element, the element
1586 * will be freed in the process of removing it from the bin. If you
1587 * want the element to still exist after removing, you need to call
1588 * gst_object_ref() before removing it from the bin.
1590 * If the element's pads are linked to other pads, the pads will be unlinked
1591 * before the element is removed from the bin.
1595 * Returns: %TRUE if the element could be removed, %FALSE if
1596 * the bin does not want to remove the element.
1599 gst_bin_remove (GstBin * bin, GstElement * element)
1601 GstBinClass *bclass;
1604 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1605 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1607 bclass = GST_BIN_GET_CLASS (bin);
1609 if (G_UNLIKELY (bclass->remove_element == NULL))
1612 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1613 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1615 result = bclass->remove_element (bin, element);
1619 /* ERROR handling */
1622 g_warning ("removing elements from bin '%s' is not supported",
1623 GST_ELEMENT_NAME (bin));
1629 * gst_bin_iterate_elements:
1632 * Gets an iterator for the elements in this bin.
1634 * MT safe. Caller owns returned value.
1636 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1640 gst_bin_iterate_elements (GstBin * bin)
1642 GstIterator *result;
1644 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1646 GST_OBJECT_LOCK (bin);
1647 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1648 GST_OBJECT_GET_LOCK (bin),
1649 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1650 GST_OBJECT_UNLOCK (bin);
1655 static GstIteratorItem
1656 iterate_child_recurse (GstIterator * it, const GValue * item)
1658 GstElement *child = g_value_get_object (item);
1660 if (GST_IS_BIN (child)) {
1661 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1663 gst_iterator_push (it, other);
1665 return GST_ITERATOR_ITEM_PASS;
1669 * gst_bin_iterate_recurse:
1672 * Gets an iterator for the elements in this bin.
1673 * This iterator recurses into GstBin children.
1675 * MT safe. Caller owns returned value.
1677 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1681 gst_bin_iterate_recurse (GstBin * bin)
1683 GstIterator *result;
1685 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1687 GST_OBJECT_LOCK (bin);
1688 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1689 GST_OBJECT_GET_LOCK (bin),
1690 &bin->children_cookie,
1692 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1693 GST_OBJECT_UNLOCK (bin);
1698 /* returns 0 when TRUE because this is a GCompareFunc */
1701 bin_element_is_sink (GstElement * child, GstBin * bin)
1705 /* we lock the child here for the remainder of the function to
1706 * get its name and flag safely. */
1707 GST_OBJECT_LOCK (child);
1708 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1710 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1711 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1713 GST_OBJECT_UNLOCK (child);
1714 return is_sink ? 0 : 1;
1718 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1720 GstBin *bin = g_value_get_object (vbin);
1721 GstElement *child = g_value_get_object (vchild);
1723 return (bin_element_is_sink (child, bin));
1727 * gst_bin_iterate_sinks:
1730 * Gets an iterator for all elements in the bin that have the
1731 * #GST_ELEMENT_FLAG_SINK flag set.
1733 * MT safe. Caller owns returned value.
1735 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1739 gst_bin_iterate_sinks (GstBin * bin)
1741 GstIterator *children;
1742 GstIterator *result;
1743 GValue vbin = { 0, };
1745 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1747 g_value_init (&vbin, GST_TYPE_BIN);
1748 g_value_set_object (&vbin, bin);
1750 children = gst_bin_iterate_elements (bin);
1751 result = gst_iterator_filter (children,
1752 (GCompareFunc) sink_iterator_filter, &vbin);
1754 g_value_unset (&vbin);
1759 /* returns 0 when TRUE because this is a GCompareFunc */
1762 bin_element_is_src (GstElement * child, GstBin * bin)
1766 /* we lock the child here for the remainder of the function to
1767 * get its name and other info safely. */
1768 GST_OBJECT_LOCK (child);
1769 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1771 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1772 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1774 GST_OBJECT_UNLOCK (child);
1775 return is_src ? 0 : 1;
1779 src_iterator_filter (const GValue * vchild, GValue * vbin)
1781 GstBin *bin = g_value_get_object (vbin);
1782 GstElement *child = g_value_get_object (vchild);
1784 return (bin_element_is_src (child, bin));
1788 * gst_bin_iterate_sources:
1791 * Gets an iterator for all elements in the bin that have the
1792 * #GST_ELEMENT_FLAG_SOURCE flag set.
1794 * MT safe. Caller owns returned value.
1796 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1800 gst_bin_iterate_sources (GstBin * bin)
1802 GstIterator *children;
1803 GstIterator *result;
1804 GValue vbin = { 0, };
1806 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1808 g_value_init (&vbin, GST_TYPE_BIN);
1809 g_value_set_object (&vbin, bin);
1811 children = gst_bin_iterate_elements (bin);
1812 result = gst_iterator_filter (children,
1813 (GCompareFunc) src_iterator_filter, &vbin);
1815 g_value_unset (&vbin);
1823 static GstStateChangeReturn
1824 gst_bin_get_state_func (GstElement * element, GstState * state,
1825 GstState * pending, GstClockTime timeout)
1827 GstStateChangeReturn ret;
1829 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1832 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1838 /***********************************************
1839 * Topologically sorted iterator
1840 * see http://en.wikipedia.org/wiki/Topological_sorting
1842 * For each element in the graph, an entry is kept in a HashTable
1843 * with its number of srcpad connections (degree).
1844 * We then change state of all elements without dependencies
1845 * (degree 0) and decrement the degree of all elements connected
1846 * on the sinkpads. When an element reaches degree 0, its state is
1848 * When all elements are handled the algorithm stops.
1850 typedef struct _GstBinSortIterator
1853 GQueue queue; /* elements queued for state change */
1854 GstBin *bin; /* bin we iterate */
1855 gint mode; /* adding or removing dependency */
1856 GstElement *best; /* next element with least dependencies */
1857 gint best_deg; /* best degree */
1858 GHashTable *hash; /* hashtable with element dependencies */
1859 gboolean dirty; /* we detected structure change */
1860 } GstBinSortIterator;
1863 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1864 GstBinSortIterator * copy)
1866 GHashTableIter iter;
1867 gpointer key, value;
1869 copy->queue = it->queue;
1870 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1872 copy->bin = gst_object_ref (it->bin);
1874 copy->best = gst_object_ref (it->best);
1876 copy->hash = g_hash_table_new (NULL, NULL);
1877 g_hash_table_iter_init (&iter, it->hash);
1878 while (g_hash_table_iter_next (&iter, &key, &value))
1879 g_hash_table_insert (copy->hash, key, value);
1882 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1883 #define HASH_SET_DEGREE(bit, elem, deg) \
1884 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1885 #define HASH_GET_DEGREE(bit, elem) \
1886 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1888 /* add element to queue of next elements in the iterator.
1889 * We push at the tail to give higher priority elements a
1892 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1894 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1895 GST_ELEMENT_NAME (element));
1896 gst_object_ref (element);
1897 g_queue_push_tail (&bit->queue, element);
1898 HASH_SET_DEGREE (bit, element, -1);
1902 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1906 if ((find = g_queue_find (&bit->queue, element))) {
1907 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1908 GST_ELEMENT_NAME (element));
1910 g_queue_delete_link (&bit->queue, find);
1911 gst_object_unref (element);
1913 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1914 GST_ELEMENT_NAME (element));
1918 /* clear the queue, unref all objects as we took a ref when
1919 * we added them to the queue */
1921 clear_queue (GQueue * queue)
1925 while ((p = g_queue_pop_head (queue)))
1926 gst_object_unref (p);
1929 /* set all degrees to 0. Elements marked as a sink are
1930 * added to the queue immediately. Since we only look at the SINK flag of the
1931 * element, it is possible that we add non-sinks to the queue. These will be
1932 * removed from the queue again when we can prove that it provides data for some
1935 reset_degree (GstElement * element, GstBinSortIterator * bit)
1939 /* sinks are added right away */
1940 GST_OBJECT_LOCK (element);
1941 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1942 GST_OBJECT_UNLOCK (element);
1945 add_to_queue (bit, element);
1947 /* others are marked with 0 and handled when sinks are done */
1948 HASH_SET_DEGREE (bit, element, 0);
1952 /* adjust the degree of all elements connected to the given
1953 * element. If a degree of an element drops to 0, it is
1954 * added to the queue of elements to schedule next.
1956 * We have to make sure not to cross the bin boundary this element
1960 update_degree (GstElement * element, GstBinSortIterator * bit)
1962 gboolean linked = FALSE;
1964 GST_OBJECT_LOCK (element);
1965 /* don't touch degree if element has no sinkpads */
1966 if (element->numsinkpads != 0) {
1967 /* loop over all sinkpads, decrement degree for all connected
1968 * elements in this bin */
1971 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1974 pad = GST_PAD_CAST (pads->data);
1976 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1977 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1978 GST_MESSAGE_STRUCTURE_CHANGE))) {
1979 /* mark the iterator as dirty because we won't be updating the degree
1980 * of the peer parent now. This would result in the 'loop detected'
1981 * later on because the peer parent element could become the best next
1982 * element with a degree > 0. We will simply continue our state
1983 * changes and we'll eventually resync when the unlink completed and
1984 * the iterator cookie is updated. */
1989 if ((peer = gst_pad_get_peer (pad))) {
1990 GstElement *peer_element;
1992 if ((peer_element = gst_pad_get_parent_element (peer))) {
1993 GST_OBJECT_LOCK (peer_element);
1994 /* check that we don't go outside of this bin */
1995 if (GST_OBJECT_CAST (peer_element)->parent ==
1996 GST_OBJECT_CAST (bit->bin)) {
1997 gint old_deg, new_deg;
1999 old_deg = HASH_GET_DEGREE (bit, peer_element);
2001 /* check to see if we added an element as sink that was not really a
2002 * sink because it was connected to some other element. */
2003 if (old_deg == -1) {
2004 remove_from_queue (bit, peer_element);
2007 new_deg = old_deg + bit->mode;
2009 GST_DEBUG_OBJECT (bit->bin,
2010 "change element %s, degree %d->%d, linked to %s",
2011 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
2012 GST_ELEMENT_NAME (element));
2014 /* update degree, it is possible that an element was in 0 and
2015 * reaches -1 here. This would mean that the element had no sinkpads
2016 * but became linked while the state change was happening. We will
2017 * resync on this with the structure change message. */
2019 /* degree hit 0, add to queue */
2020 add_to_queue (bit, peer_element);
2022 HASH_SET_DEGREE (bit, peer_element, new_deg);
2026 GST_OBJECT_UNLOCK (peer_element);
2027 gst_object_unref (peer_element);
2029 gst_object_unref (peer);
2034 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
2035 GST_ELEMENT_NAME (element));
2037 GST_OBJECT_UNLOCK (element);
2040 /* find the next best element not handled yet. This is the one
2041 * with the lowest non-negative degree */
2043 find_element (GstElement * element, GstBinSortIterator * bit)
2047 /* element is already handled */
2048 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
2051 /* first element or element with smaller degree */
2052 if (bit->best == NULL || bit->best_deg > degree) {
2053 bit->best = element;
2054 bit->best_deg = degree;
2058 /* get next element in iterator. */
2059 static GstIteratorResult
2060 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2063 GstBin *bin = bit->bin;
2065 /* empty queue, we have to find a next best element */
2066 if (g_queue_is_empty (&bit->queue)) {
2068 bit->best_deg = G_MAXINT;
2069 g_list_foreach (bin->children, (GFunc) find_element, bit);
2070 if ((best = bit->best)) {
2071 /* when we detected an unlink, don't warn because our degrees might be
2072 * screwed up. We will resync later */
2073 if (bit->best_deg != 0 && !bit->dirty) {
2074 /* we don't fail on this one yet */
2075 GST_WARNING_OBJECT (bin, "loop dected in graph");
2076 g_warning ("loop detected in the graph of bin '%s'!!",
2077 GST_ELEMENT_NAME (bin));
2079 /* best unhandled element, schedule as next element */
2080 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2081 GST_ELEMENT_NAME (best));
2082 HASH_SET_DEGREE (bit, best, -1);
2083 g_value_set_object (result, best);
2085 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2086 /* no more unhandled elements, we are done */
2087 return GST_ITERATOR_DONE;
2090 /* everything added to the queue got reffed */
2091 best = g_queue_pop_head (&bit->queue);
2092 g_value_set_object (result, best);
2093 gst_object_unref (best);
2096 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2097 /* update degrees of linked elements */
2098 update_degree (best, bit);
2100 return GST_ITERATOR_OK;
2103 /* clear queues, recalculate the degrees and restart. */
2105 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2107 GstBin *bin = bit->bin;
2109 GST_DEBUG_OBJECT (bin, "resync");
2111 clear_queue (&bit->queue);
2113 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2114 /* calc degrees, incrementing */
2116 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2117 /* for the rest of the function we decrement the degrees */
2121 /* clear queues, unref bin and free iterator. */
2123 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2125 GstBin *bin = bit->bin;
2127 GST_DEBUG_OBJECT (bin, "free");
2128 clear_queue (&bit->queue);
2129 g_hash_table_destroy (bit->hash);
2130 gst_object_unref (bin);
2133 /* should be called with the bin LOCK held */
2134 static GstIterator *
2135 gst_bin_sort_iterator_new (GstBin * bin)
2137 GstBinSortIterator *result;
2139 /* we don't need an ItemFunction because we ref the items in the _next
2141 result = (GstBinSortIterator *)
2142 gst_iterator_new (sizeof (GstBinSortIterator),
2144 GST_OBJECT_GET_LOCK (bin),
2145 &bin->priv->structure_cookie,
2146 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2147 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2148 (GstIteratorItemFunction) NULL,
2149 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2150 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2151 g_queue_init (&result->queue);
2152 result->hash = g_hash_table_new (NULL, NULL);
2153 gst_object_ref (bin);
2155 gst_bin_sort_iterator_resync (result);
2157 return (GstIterator *) result;
2161 * gst_bin_iterate_sorted:
2164 * Gets an iterator for the elements in this bin in topologically
2165 * sorted order. This means that the elements are returned from
2166 * the most downstream elements (sinks) to the sources.
2168 * This function is used internally to perform the state changes
2169 * of the bin elements and for clock selection.
2171 * MT safe. Caller owns returned value.
2173 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
2177 gst_bin_iterate_sorted (GstBin * bin)
2179 GstIterator *result;
2181 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2183 GST_OBJECT_LOCK (bin);
2184 result = gst_bin_sort_iterator_new (bin);
2185 GST_OBJECT_UNLOCK (bin);
2190 static GstStateChangeReturn
2191 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2192 GstClockTime base_time, GstClockTime start_time, GstState current,
2195 GstStateChangeReturn ret;
2196 GstState child_current, child_pending;
2200 GST_STATE_LOCK (element);
2202 GST_OBJECT_LOCK (element);
2203 /* set base_time and start time on child */
2204 GST_ELEMENT_START_TIME (element) = start_time;
2205 element->base_time = base_time;
2206 /* peel off the locked flag */
2207 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2208 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2209 ret = GST_STATE_RETURN (element);
2210 child_current = GST_STATE (element);
2211 child_pending = GST_STATE_PENDING (element);
2212 GST_OBJECT_UNLOCK (element);
2214 /* skip locked elements */
2215 if (G_UNLIKELY (locked))
2218 /* if the element was no preroll, just start changing the state regardless
2219 * if it had async elements (in the case of a bin) because they won't preroll
2221 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2222 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2226 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2227 "current %s pending %s, desired next %s",
2228 gst_element_state_get_name (child_current),
2229 gst_element_state_get_name (child_pending),
2230 gst_element_state_get_name (next));
2232 /* always recurse into bins so that we can set the base time */
2233 if (GST_IS_BIN (element))
2236 /* Try not to change the state of elements that are already in the state we're
2238 if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
2239 /* child is already at the requested state, return previous return. Note that
2240 * if the child has a pending state to next, we will still call the
2241 * set_state function */
2243 } else if (next > current) {
2244 /* upward state change */
2245 if (child_pending == GST_STATE_VOID_PENDING) {
2246 /* .. and the child is not busy doing anything */
2247 if (child_current > next) {
2248 /* .. and is already past the requested state, assume it got there
2250 ret = GST_STATE_CHANGE_SUCCESS;
2253 } else if (child_pending > child_current) {
2254 /* .. and the child is busy going upwards */
2255 if (child_current >= next) {
2256 /* .. and is already past the requested state, assume it got there
2258 ret = GST_STATE_CHANGE_SUCCESS;
2262 /* .. and the child is busy going downwards */
2263 if (child_current > next) {
2264 /* .. and is already past the requested state, assume it got there
2266 ret = GST_STATE_CHANGE_SUCCESS;
2270 } else if (next < current) {
2271 /* downward state change */
2272 if (child_pending == GST_STATE_VOID_PENDING) {
2273 /* .. and the child is not busy doing anything */
2274 if (child_current < next) {
2275 /* .. and is already past the requested state, assume it got there
2277 ret = GST_STATE_CHANGE_SUCCESS;
2280 } else if (child_pending < child_current) {
2281 /* .. and the child is busy going downwards */
2282 if (child_current <= next) {
2283 /* .. and is already past the requested state, assume it got there
2285 ret = GST_STATE_CHANGE_SUCCESS;
2289 /* .. and the child is busy going upwards */
2290 if (child_current < next) {
2291 /* .. and is already past the requested state, assume it got there
2293 ret = GST_STATE_CHANGE_SUCCESS;
2300 GST_OBJECT_LOCK (bin);
2301 /* the element was busy with an upwards async state change, we must wait for
2302 * an ASYNC_DONE message before we attemp to change the state. */
2304 find_message (bin, GST_OBJECT_CAST (element),
2305 GST_MESSAGE_ASYNC_START))) {
2306 #ifndef GST_DISABLE_GST_DEBUG
2307 GstMessage *message = GST_MESSAGE_CAST (found->data);
2309 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2310 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2312 /* only wait for upward state changes */
2313 if (next > current) {
2314 /* We found an async element check if we can force its state to change or
2315 * if we have to wait for it to preroll. */
2319 GST_OBJECT_UNLOCK (bin);
2322 GST_DEBUG_OBJECT (bin,
2323 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2324 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2325 GST_TIME_ARGS (base_time));
2328 ret = gst_element_set_state (element, next);
2330 GST_STATE_UNLOCK (element);
2336 GST_DEBUG_OBJECT (element,
2337 "element is locked, return previous return %s",
2338 gst_element_state_change_return_get_name (ret));
2339 GST_STATE_UNLOCK (element);
2344 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2345 "skipping transition from %s to %s",
2346 gst_element_state_get_name (child_current),
2347 gst_element_state_get_name (next));
2348 GST_STATE_UNLOCK (element);
2353 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2354 GST_OBJECT_UNLOCK (bin);
2355 GST_STATE_UNLOCK (element);
2356 return GST_STATE_CHANGE_ASYNC;
2360 /* gst_iterator_fold functions for pads_activate
2361 * Stop the iterator if activating one pad failed. */
2363 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2365 GstPad *pad = g_value_get_object (vpad);
2366 gboolean cont = TRUE;
2368 if (!(cont = gst_pad_set_active (pad, *active)))
2369 g_value_set_boolean (ret, FALSE);
2374 /* returns false on error or early cutout of the fold, true if all
2375 * pads in @iter were (de)activated successfully. */
2377 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2379 GstIteratorResult ires;
2382 /* no need to unset this later, it's just a boolean */
2383 g_value_init (&ret, G_TYPE_BOOLEAN);
2384 g_value_set_boolean (&ret, TRUE);
2387 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2390 case GST_ITERATOR_RESYNC:
2391 /* need to reset the result again */
2392 g_value_set_boolean (&ret, TRUE);
2393 gst_iterator_resync (iter);
2395 case GST_ITERATOR_DONE:
2396 /* all pads iterated, return collected value */
2399 /* iterator returned _ERROR or premature end with _OK,
2400 * mark an error and exit */
2401 g_value_set_boolean (&ret, FALSE);
2406 /* return collected value */
2407 return g_value_get_boolean (&ret);
2410 /* is called with STATE_LOCK
2413 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2418 GST_DEBUG_OBJECT (bin, "%s pads", active ? "activate" : "deactivate");
2420 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2421 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2422 gst_iterator_free (iter);
2423 if (G_UNLIKELY (!fold_ok))
2426 GST_DEBUG_OBJECT (bin, "pad %sactivation successful", active ? "" : "de");
2433 GST_DEBUG_OBJECT (bin, "pad %sactivation failed", active ? "" : "de");
2439 * gst_bin_recalculate_latency:
2442 * Query @bin for the current latency using and reconfigures this latency to all the
2443 * elements with a LATENCY event.
2445 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2446 * is posted on the bus.
2448 * This function simply emits the 'do-latency' signal so any custom latency
2449 * calculations will be performed.
2451 * Returns: %TRUE if the latency could be queried and reconfigured.
2454 gst_bin_recalculate_latency (GstBin * bin)
2458 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2459 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2465 gst_bin_do_latency_func (GstBin * bin)
2468 GstElement *element;
2469 GstClockTime min_latency, max_latency;
2472 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2474 element = GST_ELEMENT_CAST (bin);
2476 GST_DEBUG_OBJECT (element, "querying latency");
2478 query = gst_query_new_latency ();
2479 if ((res = gst_element_query (element, query))) {
2482 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2484 GST_DEBUG_OBJECT (element,
2485 "got min latency %" GST_TIME_FORMAT ", max latency %"
2486 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2487 GST_TIME_ARGS (max_latency), live);
2489 if (max_latency < min_latency) {
2490 /* this is an impossible situation, some parts of the pipeline might not
2491 * work correctly. We post a warning for now. */
2492 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2493 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2494 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2495 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2498 /* configure latency on elements */
2499 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2501 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2502 GST_TIME_ARGS (min_latency));
2504 GST_WARNING_OBJECT (element,
2505 "did not really configure latency of %" GST_TIME_FORMAT,
2506 GST_TIME_ARGS (min_latency));
2509 /* this is not a real problem, we just don't configure any latency. */
2510 GST_WARNING_OBJECT (element, "failed to query latency");
2512 gst_query_unref (query);
2518 gst_bin_post_message (GstElement * element, GstMessage * msg)
2520 GstElementClass *pklass = (GstElementClass *) parent_class;
2523 ret = pklass->post_message (element, gst_message_ref (msg));
2525 if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_STATE_CHANGED &&
2526 GST_MESSAGE_SRC (msg) == GST_OBJECT_CAST (element)) {
2527 GstState newstate, pending;
2529 gst_message_parse_state_changed (msg, NULL, &newstate, &pending);
2530 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING) {
2531 GST_BIN_CAST (element)->priv->posted_playing = TRUE;
2532 bin_do_eos (GST_BIN_CAST (element));
2534 GST_BIN_CAST (element)->priv->posted_playing = FALSE;
2538 gst_message_unref (msg);
2543 static GstStateChangeReturn
2544 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2547 GstStateChangeReturn ret;
2548 GstState current, next;
2549 gboolean have_async;
2550 gboolean have_no_preroll;
2551 GstClockTime base_time, start_time;
2554 GValue data = { 0, };
2556 /* we don't need to take the STATE_LOCK, it is already taken */
2557 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2558 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2560 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2561 "changing state of children from %s to %s",
2562 gst_element_state_get_name (current), gst_element_state_get_name (next));
2564 bin = GST_BIN_CAST (element);
2567 case GST_STATE_PLAYING:
2571 GST_OBJECT_LOCK (bin);
2572 toplevel = BIN_IS_TOPLEVEL (bin);
2573 GST_OBJECT_UNLOCK (bin);
2576 gst_bin_recalculate_latency (bin);
2579 case GST_STATE_PAUSED:
2580 /* Clear EOS list on next PAUSED */
2581 GST_OBJECT_LOCK (bin);
2582 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2583 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2584 bin->priv->posted_eos = FALSE;
2585 if (current == GST_STATE_READY)
2586 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
2587 GST_OBJECT_UNLOCK (bin);
2588 if (current == GST_STATE_READY)
2589 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2590 goto activate_failure;
2592 case GST_STATE_READY:
2593 /* Clear message list on next READY */
2594 GST_OBJECT_LOCK (bin);
2595 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2596 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2597 GST_OBJECT_UNLOCK (bin);
2598 /* We might not have reached PAUSED yet due to async errors,
2599 * make sure to always deactivate the pads nonetheless */
2600 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2601 goto activate_failure;
2603 case GST_STATE_NULL:
2604 if (current == GST_STATE_READY) {
2607 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2608 goto activate_failure;
2610 /* Remove all non-persistent contexts */
2611 GST_OBJECT_LOCK (bin);
2612 for (l = bin->priv->contexts; l;) {
2613 GstContext *context = l->data;
2615 if (!gst_context_is_persistent (context)) {
2618 gst_context_unref (context);
2620 bin->priv->contexts = g_list_delete_link (bin->priv->contexts, l);
2626 GST_OBJECT_UNLOCK (bin);
2633 /* this flag is used to make the async state changes return immediately. We
2634 * don't want them to interfere with this state change */
2635 GST_OBJECT_LOCK (bin);
2636 bin->polling = TRUE;
2637 GST_OBJECT_UNLOCK (bin);
2639 /* iterate in state change order */
2640 it = gst_bin_iterate_sorted (bin);
2642 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2643 * Note how we don't reset this value when a resync happens, the reason being
2644 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2645 * even after a resync when the async element is gone */
2649 /* take base_time */
2650 base_time = gst_element_get_base_time (element);
2651 start_time = gst_element_get_start_time (element);
2653 have_no_preroll = FALSE;
2657 switch (gst_iterator_next (it, &data)) {
2658 case GST_ITERATOR_OK:
2662 child = g_value_get_object (&data);
2664 /* set state and base_time now */
2665 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2669 case GST_STATE_CHANGE_SUCCESS:
2670 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2671 "child '%s' changed state to %d(%s) successfully",
2672 GST_ELEMENT_NAME (child), next,
2673 gst_element_state_get_name (next));
2675 case GST_STATE_CHANGE_ASYNC:
2677 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2678 "child '%s' is changing state asynchronously to %s",
2679 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2683 case GST_STATE_CHANGE_FAILURE:{
2686 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2687 "child '%s' failed to go to state %d(%s)",
2688 GST_ELEMENT_NAME (child),
2689 next, gst_element_state_get_name (next));
2691 /* Only fail if the child is still inside
2692 * this bin. It might've been removed already
2693 * because of the error by the bin subclass
2694 * to ignore the error. */
2695 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2696 if (parent == GST_OBJECT_CAST (element)) {
2697 /* element is still in bin, really error now */
2698 gst_object_unref (parent);
2701 /* child removed from bin, let the resync code redo the state
2703 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2704 "child '%s' was removed from the bin",
2705 GST_ELEMENT_NAME (child));
2708 gst_object_unref (parent);
2712 case GST_STATE_CHANGE_NO_PREROLL:
2713 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2714 "child '%s' changed state to %d(%s) successfully without preroll",
2715 GST_ELEMENT_NAME (child), next,
2716 gst_element_state_get_name (next));
2717 have_no_preroll = TRUE;
2720 g_assert_not_reached ();
2723 g_value_reset (&data);
2726 case GST_ITERATOR_RESYNC:
2727 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2728 gst_iterator_resync (it);
2731 case GST_ITERATOR_DONE:
2732 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2738 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2739 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2742 if (have_no_preroll) {
2743 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2744 "we have NO_PREROLL elements %s -> NO_PREROLL",
2745 gst_element_state_change_return_get_name (ret));
2746 ret = GST_STATE_CHANGE_NO_PREROLL;
2747 } else if (have_async) {
2748 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2749 "we have ASYNC elements %s -> ASYNC",
2750 gst_element_state_change_return_get_name (ret));
2751 ret = GST_STATE_CHANGE_ASYNC;
2755 g_value_unset (&data);
2756 gst_iterator_free (it);
2758 GST_OBJECT_LOCK (bin);
2759 bin->polling = FALSE;
2760 /* it's possible that we did not get ASYNC from the children while the bin is
2761 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2762 * itself as the source. In that case we still want to check if the state
2763 * change completed. */
2764 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2765 /* no element returned ASYNC and there are no pending async_done messages,
2766 * we can just complete. */
2767 GST_DEBUG_OBJECT (bin, "no async elements");
2770 /* when we get here an ASYNC element was found */
2771 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2772 /* we ignore ASYNC state changes when we go to READY or NULL */
2773 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2774 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2778 GST_DEBUG_OBJECT (bin, "check async elements");
2779 /* check if all elements managed to commit their state already */
2780 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2781 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2782 * all the elements commited their state while we were doing the state
2783 * change. We will still return ASYNC for consistency but we commit the
2784 * state already so that a _get_state() will return immediately. */
2785 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2787 GST_DEBUG_OBJECT (bin, "async elements commited");
2788 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
2789 GST_CLOCK_TIME_NONE);
2793 bin->priv->pending_async_done = FALSE;
2794 GST_OBJECT_UNLOCK (bin);
2796 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2797 "done changing bin's state from %s to %s, now in %s, ret %s",
2798 gst_element_state_get_name (current),
2799 gst_element_state_get_name (next),
2800 gst_element_state_get_name (GST_STATE (element)),
2801 gst_element_state_change_return_get_name (ret));
2808 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2809 "failure (de)activating src pads");
2810 return GST_STATE_CHANGE_FAILURE;
2815 * This function is a utility event handler for seek events.
2816 * It will send the event to all sinks or sources and appropriate
2817 * ghost pads depending on the event-direction.
2819 * Applications are free to override this behaviour and
2820 * implement their own seek handler, but this will work for
2821 * pretty much all cases in practice.
2824 gst_bin_send_event (GstElement * element, GstEvent * event)
2826 GstBin *bin = GST_BIN_CAST (element);
2828 gboolean res = TRUE;
2829 gboolean done = FALSE;
2830 GValue data = { 0, };
2832 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2833 iter = gst_bin_iterate_sources (bin);
2834 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2835 GST_EVENT_TYPE_NAME (event));
2837 iter = gst_bin_iterate_sinks (bin);
2838 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2839 GST_EVENT_TYPE_NAME (event));
2843 switch (gst_iterator_next (iter, &data)) {
2844 case GST_ITERATOR_OK:
2846 GstElement *child = g_value_get_object (&data);
2848 gst_event_ref (event);
2849 res &= gst_element_send_event (child, event);
2851 GST_LOG_OBJECT (child, "After handling %s event: %d",
2852 GST_EVENT_TYPE_NAME (event), res);
2854 g_value_reset (&data);
2857 case GST_ITERATOR_RESYNC:
2858 gst_iterator_resync (iter);
2861 case GST_ITERATOR_DONE:
2864 case GST_ITERATOR_ERROR:
2865 g_assert_not_reached ();
2869 g_value_unset (&data);
2870 gst_iterator_free (iter);
2872 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2873 iter = gst_element_iterate_sink_pads (GST_ELEMENT (bin));
2874 GST_DEBUG_OBJECT (bin, "Sending %s event to sink pads",
2875 GST_EVENT_TYPE_NAME (event));
2877 iter = gst_element_iterate_src_pads (GST_ELEMENT (bin));
2878 GST_DEBUG_OBJECT (bin, "Sending %s event to src pads",
2879 GST_EVENT_TYPE_NAME (event));
2884 switch (gst_iterator_next (iter, &data)) {
2885 case GST_ITERATOR_OK:
2887 GstPad *pad = g_value_get_object (&data);
2889 gst_event_ref (event);
2890 res &= gst_pad_send_event (pad, event);
2891 GST_LOG_OBJECT (pad, "After handling %s event: %d",
2892 GST_EVENT_TYPE_NAME (event), res);
2895 case GST_ITERATOR_RESYNC:
2896 gst_iterator_resync (iter);
2899 case GST_ITERATOR_DONE:
2902 case GST_ITERATOR_ERROR:
2903 g_assert_not_reached ();
2908 g_value_unset (&data);
2909 gst_iterator_free (iter);
2910 gst_event_unref (event);
2915 /* this is the function called by the threadpool. When async elements commit
2916 * their state, this function will attempt to bring the bin to the next state.
2919 gst_bin_continue_func (BinContinueData * data)
2922 GstState current, next, pending;
2923 GstStateChange transition;
2926 pending = data->pending;
2928 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2929 GST_STATE_LOCK (bin);
2931 GST_DEBUG_OBJECT (bin, "doing state continue");
2932 GST_OBJECT_LOCK (bin);
2934 /* if a new state change happened after this thread was scheduled, we return
2936 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2939 current = GST_STATE (bin);
2940 next = GST_STATE_GET_NEXT (current, pending);
2941 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2943 GST_STATE_NEXT (bin) = next;
2944 GST_STATE_PENDING (bin) = pending;
2946 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2947 GST_OBJECT_UNLOCK (bin);
2949 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2950 "continue state change %s to %s, final %s",
2951 gst_element_state_get_name (current),
2952 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2954 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2956 GST_STATE_UNLOCK (bin);
2957 GST_DEBUG_OBJECT (bin, "state continue done");
2959 gst_object_unref (bin);
2960 g_slice_free (BinContinueData, data);
2965 GST_OBJECT_UNLOCK (bin);
2966 GST_STATE_UNLOCK (bin);
2967 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2968 gst_object_unref (bin);
2969 g_slice_free (BinContinueData, data);
2974 static GstBusSyncReply
2975 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2977 GstBinClass *bclass;
2979 bclass = GST_BIN_GET_CLASS (bin);
2980 if (bclass->handle_message)
2981 bclass->handle_message (bin, message);
2983 gst_message_unref (message);
2985 return GST_BUS_DROP;
2989 bin_push_state_continue (BinContinueData * data)
2996 klass = GST_BIN_GET_CLASS (bin);
2998 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2999 g_thread_pool_push (klass->pool, data, NULL);
3002 /* an element started an async state change, if we were not busy with a state
3003 * change, we perform a lost state.
3004 * This function is called with the OBJECT lock.
3007 bin_handle_async_start (GstBin * bin)
3009 GstState old_state, new_state;
3011 GstMessage *amessage = NULL;
3013 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3016 /* get our toplevel state */
3017 toplevel = BIN_IS_TOPLEVEL (bin);
3019 /* prepare an ASYNC_START message, we always post the start message even if we
3020 * are busy with a state change or when we are NO_PREROLL. */
3022 /* non toplevel bin, prepare async-start for the parent */
3023 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
3025 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
3028 /* async starts are ignored when we are NO_PREROLL */
3029 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
3030 goto was_no_preroll;
3032 old_state = GST_STATE (bin);
3034 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
3035 * PLAYING after optionally redistributing the base_time. */
3036 if (old_state > GST_STATE_PAUSED)
3037 new_state = GST_STATE_PAUSED;
3039 new_state = old_state;
3041 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
3042 "lost state of %s, new %s", gst_element_state_get_name (old_state),
3043 gst_element_state_get_name (new_state));
3045 GST_STATE (bin) = new_state;
3046 GST_STATE_NEXT (bin) = new_state;
3047 GST_STATE_PENDING (bin) = new_state;
3048 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3049 GST_OBJECT_UNLOCK (bin);
3052 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
3057 /* post our ASYNC_START. */
3058 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
3059 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3061 GST_OBJECT_LOCK (bin);
3067 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3072 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3073 GST_OBJECT_UNLOCK (bin);
3078 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
3079 GST_OBJECT_UNLOCK (bin);
3084 /* this function is called when there are no more async elements in the bin. We
3085 * post a state changed message and an ASYNC_DONE message.
3086 * This function is called with the OBJECT lock.
3089 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
3090 gboolean flag_pending, GstClockTime running_time)
3092 GstState current, pending, target;
3093 GstStateChangeReturn old_ret;
3094 GstState old_state, old_next;
3095 gboolean toplevel, state_changed = FALSE;
3096 GstMessage *amessage = NULL;
3097 BinContinueData *cont = NULL;
3099 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3102 pending = GST_STATE_PENDING (bin);
3107 /* check if there is something to commit */
3108 if (pending == GST_STATE_VOID_PENDING)
3109 goto nothing_pending;
3111 old_ret = GST_STATE_RETURN (bin);
3112 GST_STATE_RETURN (bin) = ret;
3114 /* move to the next target state */
3115 target = GST_STATE_TARGET (bin);
3116 pending = GST_STATE_PENDING (bin) = target;
3118 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
3120 old_state = GST_STATE (bin);
3121 /* this is the state we should go to next */
3122 old_next = GST_STATE_NEXT (bin);
3124 if (old_next != GST_STATE_PLAYING) {
3125 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3126 "committing state from %s to %s, old pending %s",
3127 gst_element_state_get_name (old_state),
3128 gst_element_state_get_name (old_next),
3129 gst_element_state_get_name (pending));
3131 /* update current state */
3132 current = GST_STATE (bin) = old_next;
3134 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3135 "setting state from %s to %s, pending %s",
3136 gst_element_state_get_name (old_state),
3137 gst_element_state_get_name (old_state),
3138 gst_element_state_get_name (pending));
3139 current = old_state;
3142 /* get our toplevel state */
3143 toplevel = BIN_IS_TOPLEVEL (bin);
3145 /* see if we reached the final state. If we are not toplevel, we also have to
3146 * stop here, the parent will continue our state. */
3147 if ((pending == current) || !toplevel) {
3148 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3149 "completed state change, pending VOID");
3151 /* mark VOID pending */
3152 pending = GST_STATE_VOID_PENDING;
3153 GST_STATE_PENDING (bin) = pending;
3154 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
3156 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3157 "continue state change, pending %s",
3158 gst_element_state_get_name (pending));
3160 cont = g_slice_new (BinContinueData);
3162 /* ref to the bin */
3163 cont->bin = gst_object_ref (bin);
3164 /* cookie to detect concurrent state change */
3165 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3166 /* pending target state */
3167 cont->pending = pending;
3169 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3170 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3173 if (old_next != GST_STATE_PLAYING) {
3174 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3175 state_changed = TRUE;
3178 GST_OBJECT_UNLOCK (bin);
3180 if (state_changed) {
3181 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3185 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3186 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3187 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3190 GST_OBJECT_LOCK (bin);
3192 /* toplevel, start continue state */
3193 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3194 bin_push_state_continue (cont);
3196 GST_DEBUG_OBJECT (bin, "state change complete");
3197 GST_STATE_BROADCAST (bin);
3203 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3208 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3209 /* if we were busy with a state change and we are requested to flag a
3210 * pending async done, we do so here */
3212 bin->priv->pending_async_done = TRUE;
3217 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3223 bin_do_eos (GstBin * bin)
3228 GST_OBJECT_LOCK (bin);
3229 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3230 * we forward the EOS message to the parent bin or application
3232 eos = GST_STATE (bin) == GST_STATE_PLAYING
3233 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3234 && bin->priv->posted_playing && is_eos (bin, &seqnum);
3235 GST_OBJECT_UNLOCK (bin);
3238 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3240 GstMessage *tmessage;
3242 /* Clear out any further messages, and reset posted_eos so we can
3243 detect any new EOS that happens (eg, after a seek). Since all
3244 sinks have now posted an EOS, there will be no further EOS events
3245 seen unless there is a new logical EOS */
3246 GST_OBJECT_LOCK (bin);
3247 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3248 bin->priv->posted_eos = FALSE;
3249 GST_OBJECT_UNLOCK (bin);
3251 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3252 gst_message_set_seqnum (tmessage, seqnum);
3253 GST_DEBUG_OBJECT (bin,
3254 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3255 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3260 bin_do_stream_start (GstBin * bin)
3263 gboolean stream_start;
3264 gboolean have_group_id = FALSE;
3267 GST_OBJECT_LOCK (bin);
3268 /* If all sinks are STREAM_START we forward the STREAM_START message
3269 * to the parent bin or application
3271 stream_start = is_stream_start (bin, &seqnum, &have_group_id, &group_id);
3272 GST_OBJECT_UNLOCK (bin);
3275 GstMessage *tmessage;
3277 GST_OBJECT_LOCK (bin);
3278 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
3279 GST_OBJECT_UNLOCK (bin);
3281 tmessage = gst_message_new_stream_start (GST_OBJECT_CAST (bin));
3282 gst_message_set_seqnum (tmessage, seqnum);
3284 gst_message_set_group_id (tmessage, group_id);
3286 GST_DEBUG_OBJECT (bin,
3287 "all sinks posted STREAM_START, posting seqnum #%" G_GUINT32_FORMAT,
3289 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3293 /* must be called without the object lock as it posts messages */
3295 bin_do_message_forward (GstBin * bin, GstMessage * message)
3297 if (bin->priv->message_forward) {
3298 GstMessage *forwarded;
3300 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3301 GST_MESSAGE_TYPE_NAME (message));
3303 /* we need to convert these messages to element messages so that our parent
3304 * bin can easily ignore them and so that the application can easily
3305 * distinguish between the internally forwarded and the real messages. */
3306 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3307 gst_structure_new ("GstBinForwarded",
3308 "message", GST_TYPE_MESSAGE, message, NULL));
3310 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3315 gst_bin_update_context (GstBin * bin, GstContext * context)
3318 const gchar *context_type;
3320 GST_OBJECT_LOCK (bin);
3321 context_type = gst_context_get_context_type (context);
3322 for (l = bin->priv->contexts; l; l = l->next) {
3323 GstContext *tmp = l->data;
3324 const gchar *tmp_type = gst_context_get_context_type (tmp);
3326 /* Always store newest context but never replace
3327 * a persistent one by a non-persistent one */
3328 if (strcmp (context_type, tmp_type) == 0 &&
3329 (gst_context_is_persistent (context) ||
3330 !gst_context_is_persistent (tmp))) {
3331 gst_context_replace ((GstContext **) & l->data, context);
3335 /* Not found? Add */
3337 bin->priv->contexts =
3338 g_list_prepend (bin->priv->contexts, gst_context_ref (context));
3339 GST_OBJECT_UNLOCK (bin);
3342 /* handle child messages:
3344 * This method is called synchronously when a child posts a message on
3347 * GST_MESSAGE_EOS: This message is only posted by sinks
3348 * in the PLAYING state. If all sinks posted the EOS message, post
3351 * GST_MESSAGE_STATE_DIRTY: Deprecated
3353 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3354 * element posts segment_start twice, only the last message is kept.
3356 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3357 * with the segment_done message. If there are no more segment_start
3358 * messages, post segment_done message upwards.
3360 * GST_MESSAGE_DURATION_CHANGED: clear any cached durations.
3361 * Whenever someone performs a duration query on the bin, we store the
3362 * result so we can answer it quicker the next time. Any element that
3363 * changes its duration marks our cached values invalid.
3364 * This message is also posted upwards. This is currently disabled
3365 * because too many elements don't post DURATION_CHANGED messages when
3366 * the duration changes.
3368 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3369 * can no longer provide a clock. The default bin behaviour is to
3370 * check if the lost clock was the one provided by the bin. If so and
3371 * we are currently in the PLAYING state, we forward the message to
3373 * This message is also generated when we remove a clock provider from
3374 * a bin. If this message is received by the application, it should
3375 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3376 * and a new base_time distribution.
3378 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3379 * can provide a clock. This mostly happens when we add a new clock
3380 * provider to the bin. The default behaviour of the bin is to mark the
3381 * currently selected clock as dirty, which will perform a clock
3382 * recalculation the next time we are asked to provide a clock.
3383 * This message is never sent to the application but is forwarded to
3386 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3387 * the state of the element and the fact that the element will need a
3388 * new base_time. This message is not forwarded to the application.
3390 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3391 * element when it posted ASYNC_START. If all elements are done, post a
3392 * ASYNC_DONE message to the parent.
3394 * OTHER: post upwards.
3397 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3400 GstMessageType type;
3401 GstMessage *tmessage;
3404 src = GST_MESSAGE_SRC (message);
3405 type = GST_MESSAGE_TYPE (message);
3407 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3408 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3409 GST_MESSAGE_TYPE_NAME (message));
3412 case GST_MESSAGE_ERROR:
3414 GST_OBJECT_LOCK (bin);
3416 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3417 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3418 GST_STATE_BROADCAST (bin);
3419 GST_OBJECT_UNLOCK (bin);
3423 case GST_MESSAGE_EOS:
3426 /* collect all eos messages from the children */
3427 bin_do_message_forward (bin, message);
3428 GST_OBJECT_LOCK (bin);
3429 /* ref message for future use */
3430 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3431 GST_OBJECT_UNLOCK (bin);
3436 case GST_MESSAGE_STREAM_START:
3439 /* collect all stream_start messages from the children */
3440 GST_OBJECT_LOCK (bin);
3441 /* ref message for future use */
3442 bin_replace_message (bin, message, GST_MESSAGE_STREAM_START);
3443 GST_OBJECT_UNLOCK (bin);
3445 bin_do_stream_start (bin);
3448 case GST_MESSAGE_STATE_DIRTY:
3450 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3453 gst_message_unref (message);
3456 case GST_MESSAGE_SEGMENT_START:{
3457 gboolean post = FALSE;
3461 gst_message_parse_segment_start (message, &format, &position);
3462 seqnum = gst_message_get_seqnum (message);
3464 bin_do_message_forward (bin, message);
3466 GST_OBJECT_LOCK (bin);
3467 /* if this is the first segment-start, post to parent but not to the
3469 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3470 (GST_OBJECT_PARENT (bin) != NULL)) {
3473 /* replace any previous segment_start message from this source
3474 * with the new segment start message */
3475 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3476 GST_OBJECT_UNLOCK (bin);
3478 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3480 gst_message_set_seqnum (tmessage, seqnum);
3482 /* post segment start with initial format and position. */
3483 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3485 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3489 case GST_MESSAGE_SEGMENT_DONE:
3491 gboolean post = FALSE;
3495 gst_message_parse_segment_done (message, &format, &position);
3496 seqnum = gst_message_get_seqnum (message);
3498 bin_do_message_forward (bin, message);
3500 GST_OBJECT_LOCK (bin);
3501 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3502 /* if there are no more segment_start messages, everybody posted
3503 * a segment_done and we can post one on the bus. */
3505 /* we don't care who still has a pending segment start */
3506 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3509 /* remove all old segment_done messages */
3510 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3512 GST_OBJECT_UNLOCK (bin);
3514 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3516 gst_message_set_seqnum (tmessage, seqnum);
3518 /* post segment done with latest format and position. */
3519 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3521 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3525 case GST_MESSAGE_DURATION_CHANGED:
3527 /* FIXME: remove all cached durations, next time somebody asks
3528 * for duration, we will recalculate. */
3530 GST_OBJECT_LOCK (bin);
3531 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION_CHANGED);
3532 GST_OBJECT_UNLOCK (bin);
3536 case GST_MESSAGE_CLOCK_LOST:
3538 GstClock **provided_clock_p;
3539 GstElement **clock_provider_p;
3540 gboolean playing, toplevel, provided, forward;
3543 gst_message_parse_clock_lost (message, &clock);
3545 GST_OBJECT_LOCK (bin);
3546 bin->clock_dirty = TRUE;
3547 /* if we lost the clock that we provided, post to parent but
3548 * only if we are not a top-level bin or PLAYING.
3549 * The reason for this is that applications should be able
3550 * to PAUSE/PLAY if they receive this message without worrying
3551 * about the state of the pipeline. */
3552 provided = (clock == bin->provided_clock);
3553 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3554 toplevel = GST_OBJECT_PARENT (bin) == NULL;
3555 forward = provided && (playing || !toplevel);
3557 GST_DEBUG_OBJECT (bin,
3558 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3559 bin->provided_clock, bin->clock_provider);
3560 provided_clock_p = &bin->provided_clock;
3561 clock_provider_p = &bin->clock_provider;
3562 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3563 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3565 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3566 provided, playing, forward);
3567 GST_OBJECT_UNLOCK (bin);
3573 gst_message_unref (message);
3576 case GST_MESSAGE_CLOCK_PROVIDE:
3580 GST_OBJECT_LOCK (bin);
3581 bin->clock_dirty = TRUE;
3582 /* a new clock is available, post to parent but not
3583 * to the application */
3584 forward = GST_OBJECT_PARENT (bin) != NULL;
3585 GST_OBJECT_UNLOCK (bin);
3591 gst_message_unref (message);
3594 case GST_MESSAGE_ASYNC_START:
3598 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3599 src ? GST_OBJECT_NAME (src) : "(NULL)");
3601 bin_do_message_forward (bin, message);
3603 GST_OBJECT_LOCK (bin);
3604 /* we ignore the message if we are going to <= READY */
3605 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3606 goto ignore_start_message;
3608 /* takes ownership of the message */
3609 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3611 bin_handle_async_start (bin);
3612 GST_OBJECT_UNLOCK (bin);
3615 ignore_start_message:
3617 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3618 gst_element_state_get_name (target));
3619 GST_OBJECT_UNLOCK (bin);
3620 gst_message_unref (message);
3624 case GST_MESSAGE_ASYNC_DONE:
3626 GstClockTime running_time;
3629 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3630 src ? GST_OBJECT_NAME (src) : "(NULL)");
3632 gst_message_parse_async_done (message, &running_time);
3634 bin_do_message_forward (bin, message);
3636 GST_OBJECT_LOCK (bin);
3637 /* ignore messages if we are shutting down */
3638 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3639 goto ignore_done_message;
3641 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3642 /* if there are no more ASYNC_START messages, everybody posted
3643 * a ASYNC_DONE and we can post one on the bus. When checking, we
3644 * don't care who still has a pending ASYNC_START */
3645 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3646 /* nothing found, remove all old ASYNC_DONE messages */
3647 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3649 GST_DEBUG_OBJECT (bin, "async elements commited");
3650 /* when we get an async done message when a state change was busy, we
3651 * need to set the pending_done flag so that at the end of the state
3652 * change we can see if we need to verify pending async elements, hence
3653 * the TRUE argument here. */
3654 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
3657 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3659 GST_OBJECT_UNLOCK (bin);
3662 ignore_done_message:
3664 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3665 gst_element_state_get_name (target));
3666 GST_OBJECT_UNLOCK (bin);
3667 gst_message_unref (message);
3671 case GST_MESSAGE_STRUCTURE_CHANGE:
3675 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3677 GST_OBJECT_LOCK (bin);
3679 /* while the pad is busy, avoid following it when doing state changes.
3680 * Don't update the cookie yet, we will do that after the structure
3681 * change finished and we are ready to inspect the new updated
3683 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3686 /* a pad link/unlink ended, signal the state change iterator that we
3687 * need to resync by updating the structure_cookie. */
3688 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3689 GST_MESSAGE_STRUCTURE_CHANGE);
3690 if (!GST_BIN_IS_NO_RESYNC (bin))
3691 bin->priv->structure_cookie++;
3693 GST_OBJECT_UNLOCK (bin);
3696 gst_message_unref (message);
3700 case GST_MESSAGE_NEED_CONTEXT:{
3701 const gchar *context_type;
3704 gst_message_parse_context_type (message, &context_type);
3705 GST_OBJECT_LOCK (bin);
3706 for (l = bin->priv->contexts; l; l = l->next) {
3707 GstContext *tmp = l->data;
3708 const gchar *tmp_type = gst_context_get_context_type (tmp);
3710 if (strcmp (context_type, tmp_type) == 0) {
3711 gst_element_set_context (GST_ELEMENT (src), l->data);
3715 GST_OBJECT_UNLOCK (bin);
3717 /* Forward if we couldn't answer the message */
3721 gst_message_unref (message);
3726 case GST_MESSAGE_HAVE_CONTEXT:{
3727 GstContext *context;
3729 gst_message_parse_have_context (message, &context);
3730 gst_bin_update_context (bin, context);
3731 gst_context_unref (context);
3743 /* Send all other messages upward */
3744 GST_DEBUG_OBJECT (bin, "posting message upward");
3745 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3750 /* generic struct passed to all query fold methods */
3759 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3760 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3762 /* for duration/position we collect all durations/positions and take
3763 * the MAX of all valid results */
3765 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3773 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3775 gboolean res = FALSE;
3776 GstObject *item = g_value_get_object (vitem);
3777 if (GST_IS_PAD (item))
3778 res = gst_pad_query (GST_PAD (item), fold->query);
3780 res = gst_element_query (GST_ELEMENT (item), fold->query);
3785 g_value_set_boolean (ret, TRUE);
3787 gst_query_parse_duration (fold->query, NULL, &duration);
3789 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3791 if (duration == -1) {
3792 /* duration query succeeded, but duration is unknown */
3797 if (duration > fold->max)
3798 fold->max = duration;
3805 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3809 gst_query_parse_duration (fold->query, &format, NULL);
3810 /* store max in query result */
3811 gst_query_set_duration (fold->query, format, fold->max);
3813 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3815 /* FIXME: re-implement duration caching */
3818 GST_OBJECT_LOCK (bin);
3819 bin->messages = g_list_prepend (bin->messages,
3820 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3821 GST_OBJECT_UNLOCK (bin);
3826 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3828 gboolean res = FALSE;
3829 GstObject *item = g_value_get_object (vitem);
3830 if (GST_IS_PAD (item))
3831 res = gst_pad_query (GST_PAD (item), fold->query);
3833 res = gst_element_query (GST_ELEMENT (item), fold->query);
3838 g_value_set_boolean (ret, TRUE);
3840 gst_query_parse_position (fold->query, NULL, &position);
3842 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3844 if (position > fold->max)
3845 fold->max = position;
3852 bin_query_position_done (GstBin * bin, QueryFold * fold)
3856 gst_query_parse_position (fold->query, &format, NULL);
3857 /* store max in query result */
3858 gst_query_set_position (fold->query, format, fold->max);
3860 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3864 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3866 gboolean res = FALSE;
3867 GstObject *item = g_value_get_object (vitem);
3868 if (GST_IS_PAD (item))
3869 res = gst_pad_query (GST_PAD (item), fold->query);
3871 res = gst_element_query (GST_ELEMENT (item), fold->query);
3873 GstClockTime min, max;
3876 gst_query_parse_latency (fold->query, &live, &min, &max);
3878 GST_DEBUG_OBJECT (item,
3879 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3880 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3882 /* for the combined latency we collect the MAX of all min latencies and
3883 * the MIN of all max latencies */
3885 if (min > fold->min)
3887 if (fold->max == -1)
3889 else if (max < fold->max)
3895 g_value_set_boolean (ret, FALSE);
3896 GST_DEBUG_OBJECT (item, "failed query");
3903 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3905 /* store max in query result */
3906 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3908 GST_DEBUG_OBJECT (bin,
3909 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3910 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3914 /* generic fold, return first valid result */
3916 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3918 gboolean res = FALSE;
3919 GstObject *item = g_value_get_object (vitem);
3920 if (GST_IS_PAD (item))
3921 res = gst_pad_query (GST_PAD (item), fold->query);
3923 res = gst_element_query (GST_ELEMENT (item), fold->query);
3925 g_value_set_boolean (ret, TRUE);
3926 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3929 /* and stop as soon as we have a valid result */
3933 /* Perform a query iteration for the given bin. The query is stored in
3934 * QueryFold and iter should be either a GstPad iterator or a
3935 * GstElement iterator. */
3937 bin_iterate_fold (GstBin * bin, GstIterator * iter, QueryInitFunction fold_init,
3938 QueryDoneFunction fold_done, GstIteratorFoldFunction fold_func,
3939 QueryFold fold_data, gboolean default_return)
3941 gboolean res = default_return;
3943 /* set the result of the query to FALSE initially */
3944 g_value_init (&ret, G_TYPE_BOOLEAN);
3945 g_value_set_boolean (&ret, res);
3948 GstIteratorResult ires;
3950 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3953 case GST_ITERATOR_RESYNC:
3954 gst_iterator_resync (iter);
3956 fold_init (bin, &fold_data);
3957 g_value_set_boolean (&ret, res);
3959 case GST_ITERATOR_OK:
3960 case GST_ITERATOR_DONE:
3961 res = g_value_get_boolean (&ret);
3962 if (fold_done != NULL && res)
3963 fold_done (bin, &fold_data);
3975 gst_bin_query (GstElement * element, GstQuery * query)
3977 GstBin *bin = GST_BIN_CAST (element);
3979 gboolean default_return = FALSE;
3980 gboolean res = FALSE;
3981 gboolean src_pads_query_result = FALSE;
3982 GstIteratorFoldFunction fold_func;
3983 QueryInitFunction fold_init = NULL;
3984 QueryDoneFunction fold_done = NULL;
3985 QueryFold fold_data;
3987 switch (GST_QUERY_TYPE (query)) {
3988 case GST_QUERY_DURATION:
3990 /* FIXME: implement duration caching in GstBin again */
3995 gst_query_parse_duration (query, &qformat, NULL);
3997 /* find cached duration query */
3998 GST_OBJECT_LOCK (bin);
3999 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
4000 GstMessage *message = (GstMessage *) cached->data;
4002 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION_CHANGED &&
4003 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
4007 gst_message_parse_duration (message, &format, &duration);
4009 /* if cached same format, copy duration in query result */
4010 if (format == qformat) {
4011 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
4013 GST_OBJECT_UNLOCK (bin);
4015 gst_query_set_duration (query, qformat, duration);
4021 GST_OBJECT_UNLOCK (bin);
4023 GST_FIXME ("implement duration caching in GstBin again");
4025 /* no cached value found, iterate and collect durations */
4026 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
4027 fold_init = bin_query_min_max_init;
4028 fold_done = bin_query_duration_done;
4031 case GST_QUERY_POSITION:
4033 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
4034 fold_init = bin_query_min_max_init;
4035 fold_done = bin_query_position_done;
4038 case GST_QUERY_LATENCY:
4040 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
4041 fold_init = bin_query_min_max_init;
4042 fold_done = bin_query_latency_done;
4043 default_return = TRUE;
4047 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
4051 fold_data.query = query;
4053 iter = gst_bin_iterate_sinks (bin);
4054 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
4055 query, GST_QUERY_TYPE_NAME (query));
4058 fold_init (bin, &fold_data);
4061 bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func, fold_data,
4063 gst_iterator_free (iter);
4066 /* Query the source pads of the element */
4067 iter = gst_element_iterate_src_pads (element);
4068 src_pads_query_result =
4069 bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func,
4070 fold_data, default_return);
4071 gst_iterator_free (iter);
4073 if (src_pads_query_result)
4077 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
4083 set_context (const GValue * item, gpointer user_data)
4085 GstElement *element = g_value_get_object (item);
4087 gst_element_set_context (element, user_data);
4091 gst_bin_set_context (GstElement * element, GstContext * context)
4094 GstIterator *children;
4096 g_return_if_fail (GST_IS_BIN (element));
4098 bin = GST_BIN (element);
4100 gst_bin_update_context (bin, context);
4102 children = gst_bin_iterate_elements (bin);
4103 while (gst_iterator_foreach (children, set_context,
4104 context) == GST_ITERATOR_RESYNC)
4105 gst_iterator_resync (children);
4106 gst_iterator_free (children);
4110 compare_name (const GValue * velement, const gchar * name)
4113 GstElement *element = g_value_get_object (velement);
4115 GST_OBJECT_LOCK (element);
4116 eq = strcmp (GST_ELEMENT_NAME (element), name);
4117 GST_OBJECT_UNLOCK (element);
4123 * gst_bin_get_by_name:
4125 * @name: the element name to search for
4127 * Gets the element with the given name from a bin. This
4128 * function recurses into child bins.
4130 * Returns %NULL if no element with the given name is found in the bin.
4132 * MT safe. Caller owns returned reference.
4134 * Returns: (transfer full) (nullable): the #GstElement with the given
4138 gst_bin_get_by_name (GstBin * bin, const gchar * name)
4140 GstIterator *children;
4141 GValue result = { 0, };
4142 GstElement *element;
4145 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4147 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
4148 GST_ELEMENT_NAME (bin), name);
4150 children = gst_bin_iterate_recurse (bin);
4151 found = gst_iterator_find_custom (children,
4152 (GCompareFunc) compare_name, &result, (gpointer) name);
4153 gst_iterator_free (children);
4156 element = g_value_dup_object (&result);
4157 g_value_unset (&result);
4166 * gst_bin_get_by_name_recurse_up:
4168 * @name: the element name to search for
4170 * Gets the element with the given name from this bin. If the
4171 * element is not found, a recursion is performed on the parent bin.
4174 * - no element with the given name is found in the bin
4176 * MT safe. Caller owns returned reference.
4178 * Returns: (transfer full) (nullable): the #GstElement with the given
4182 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
4186 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4187 g_return_val_if_fail (name != NULL, NULL);
4189 result = gst_bin_get_by_name (bin, name);
4194 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
4196 if (GST_IS_BIN (parent)) {
4197 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
4199 gst_object_unref (parent);
4207 compare_interface (const GValue * velement, GValue * interface)
4209 GstElement *element = g_value_get_object (velement);
4210 GType interface_type = (GType) g_value_get_pointer (interface);
4213 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
4222 * gst_bin_get_by_interface:
4224 * @iface: the #GType of an interface
4226 * Looks for an element inside the bin that implements the given
4227 * interface. If such an element is found, it returns the element.
4228 * You can cast this element to the given interface afterwards. If you want
4229 * all elements that implement the interface, use
4230 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
4232 * MT safe. Caller owns returned reference.
4234 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
4237 gst_bin_get_by_interface (GstBin * bin, GType iface)
4239 GstIterator *children;
4240 GValue result = { 0, };
4241 GstElement *element;
4243 GValue viface = { 0, };
4245 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4246 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4248 g_value_init (&viface, G_TYPE_POINTER);
4249 g_value_set_pointer (&viface, (gpointer) iface);
4251 children = gst_bin_iterate_recurse (bin);
4252 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
4254 gst_iterator_free (children);
4257 element = g_value_dup_object (&result);
4258 g_value_unset (&result);
4262 g_value_unset (&viface);
4268 * gst_bin_iterate_all_by_interface:
4270 * @iface: the #GType of an interface
4272 * Looks for all elements inside the bin that implements the given
4273 * interface. You can safely cast all returned elements to the given interface.
4274 * The function recurses inside child bins. The iterator will yield a series
4275 * of #GstElement that should be unreffed after use.
4277 * MT safe. Caller owns returned value.
4279 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement
4280 * for all elements in the bin implementing the given interface,
4284 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
4286 GstIterator *children;
4287 GstIterator *result;
4288 GValue viface = { 0, };
4290 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4291 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4293 g_value_init (&viface, G_TYPE_POINTER);
4294 g_value_set_pointer (&viface, (gpointer) iface);
4296 children = gst_bin_iterate_recurse (bin);
4297 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
4300 g_value_unset (&viface);