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., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, 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</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.
157 * Last reviewed on 2012-03-28 (0.11.3)
160 #include "gst_private.h"
162 #include "gstevent.h"
165 #include "gsterror.h"
167 #include "gstutils.h"
168 #include "gstchildproxy.h"
170 GST_DEBUG_CATEGORY_STATIC (bin_debug);
171 #define GST_CAT_DEFAULT bin_debug
173 /* a bin is toplevel if it has no parent or when it is configured to behave like
175 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
177 #define GST_BIN_GET_PRIVATE(obj) \
178 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
180 struct _GstBinPrivate
182 gboolean asynchandling;
183 /* if we get an ASYNC_DONE message from ourselves, this means that the
184 * subclass will simulate ASYNC behaviour without having ASYNC children. When
185 * such an ASYNC_DONE message is posted while we are doing a state change, we
186 * have to process the message after finishing the state change even when no
187 * child returned GST_STATE_CHANGE_ASYNC. */
188 gboolean pending_async_done;
190 guint32 structure_cookie;
197 /* forward messages from our children */
198 gboolean message_forward;
210 static void gst_bin_dispose (GObject * object);
212 static void gst_bin_set_property (GObject * object, guint prop_id,
213 const GValue * value, GParamSpec * pspec);
214 static void gst_bin_get_property (GObject * object, guint prop_id,
215 GValue * value, GParamSpec * pspec);
217 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
218 GstStateChange transition);
219 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
220 GstState newstate, GstState pending);
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);
246 static gboolean gst_bin_do_latency_func (GstBin * bin);
248 static void bin_remove_messages (GstBin * bin, GstObject * src,
249 GstMessageType types);
250 static void gst_bin_continue_func (BinContinueData * data);
251 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
252 static gint bin_element_is_src (GstElement * child, GstBin * bin);
254 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
256 /* Bin signals and properties */
265 #define DEFAULT_ASYNC_HANDLING FALSE
266 #define DEFAULT_MESSAGE_FORWARD FALSE
272 PROP_MESSAGE_FORWARD,
276 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
278 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
282 static const GInterfaceInfo iface_info = { \
283 gst_bin_child_proxy_init, \
287 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
289 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
290 "debugging info for the 'bin' container element"); \
294 #define gst_bin_parent_class parent_class
295 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
298 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
304 bin = GST_BIN_CAST (child_proxy);
306 GST_OBJECT_LOCK (bin);
307 if ((res = g_list_nth_data (bin->children, index)))
308 gst_object_ref (res);
309 GST_OBJECT_UNLOCK (bin);
311 return (GObject *) res;
315 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
320 bin = GST_BIN_CAST (child_proxy);
322 GST_OBJECT_LOCK (bin);
323 num = bin->numchildren;
324 GST_OBJECT_UNLOCK (bin);
330 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
332 GstChildProxyInterface *iface = g_iface;
334 iface->get_children_count = gst_bin_child_proxy_get_children_count;
335 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
339 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
340 GValue * return_accu, const GValue * handler_return, gpointer dummy)
344 myboolean = g_value_get_boolean (handler_return);
345 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
346 g_value_set_boolean (return_accu, myboolean);
348 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
355 gst_bin_class_init (GstBinClass * klass)
357 GObjectClass *gobject_class;
358 GstElementClass *gstelement_class;
361 gobject_class = (GObjectClass *) klass;
362 gstelement_class = (GstElementClass *) klass;
364 g_type_class_add_private (klass, sizeof (GstBinPrivate));
366 gobject_class->set_property = gst_bin_set_property;
367 gobject_class->get_property = gst_bin_get_property;
370 * GstBin:async-handling:
372 * If set to #TRUE, the bin will handle asynchronous state changes.
373 * This should be used only if the bin subclass is modifying the state
374 * of its children on its own.
378 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
379 g_param_spec_boolean ("async-handling", "Async Handling",
380 "The bin will handle Asynchronous state changes",
381 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
384 * GstBin::element-added:
386 * @element: the #GstElement that was added to the bin
388 * Will be emitted after the element was added to the bin.
390 gst_bin_signals[ELEMENT_ADDED] =
391 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
392 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
393 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
395 * GstBin::element-removed:
397 * @element: the #GstElement that was removed from the bin
399 * Will be emitted after the element was removed from the bin.
401 gst_bin_signals[ELEMENT_REMOVED] =
402 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
403 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
404 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
406 * GstBin::do-latency:
409 * Will be emitted when the bin needs to perform latency calculations. This
410 * signal is only emited for toplevel bins or when async-handling is
413 * Only one signal handler is invoked. If no signals are connected, the
414 * default handler is invoked, which will query and distribute the lowest
415 * possible latency to all sinks.
417 * Connect to this signal if the default latency calculations are not
418 * sufficient, like when you need different latencies for different sinks in
423 gst_bin_signals[DO_LATENCY] =
424 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
425 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
426 _gst_boolean_accumulator, NULL, g_cclosure_marshal_generic,
427 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
430 * GstBin:message-forward:
432 * Forward all children messages, even those that would normally be filtered by
433 * the bin. This can be interesting when one wants to be notified of the EOS
434 * state of individual elements, for example.
436 * The messages are converted to an ELEMENT message with the bin as the
437 * source. The structure of the message is named 'GstBinForwarded' and contains
438 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
443 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
444 g_param_spec_boolean ("message-forward", "Message Forward",
445 "Forwards all children messages",
446 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
448 gobject_class->dispose = gst_bin_dispose;
450 gst_element_class_set_metadata (gstelement_class, "Generic bin",
452 "Simple container object",
453 "Erik Walthinsen <omega@cse.ogi.edu>,"
454 "Wim Taymans <wim.taymans@gmail.com>");
456 gstelement_class->change_state =
457 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
458 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
459 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
461 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
462 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
464 gstelement_class->provide_clock =
465 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
466 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
468 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
469 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
471 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
472 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
473 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
475 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
477 GST_DEBUG ("creating bin thread pool");
480 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
482 g_critical ("could alloc threadpool %s", err->message);
487 gst_bin_init (GstBin * bin)
491 bin->numchildren = 0;
492 bin->children = NULL;
493 bin->children_cookie = 0;
494 bin->messages = NULL;
495 bin->provided_clock = NULL;
496 bin->clock_dirty = FALSE;
498 /* Set up a bus for listening to child elements */
499 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
500 bin->child_bus = bus;
501 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
503 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin,
506 bin->priv = GST_BIN_GET_PRIVATE (bin);
507 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
508 bin->priv->structure_cookie = 0;
509 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
513 gst_bin_dispose (GObject * object)
515 GstBin *bin = GST_BIN_CAST (object);
516 GstBus **child_bus_p = &bin->child_bus;
517 GstClock **provided_clock_p = &bin->provided_clock;
518 GstElement **clock_provider_p = &bin->clock_provider;
520 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
522 GST_OBJECT_LOCK (object);
523 gst_object_replace ((GstObject **) child_bus_p, NULL);
524 gst_object_replace ((GstObject **) provided_clock_p, NULL);
525 gst_object_replace ((GstObject **) clock_provider_p, NULL);
526 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
527 GST_OBJECT_UNLOCK (object);
529 while (bin->children) {
530 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
532 if (G_UNLIKELY (bin->children != NULL)) {
533 g_critical ("could not remove elements from bin '%s'",
534 GST_STR_NULL (GST_OBJECT_NAME (object)));
537 G_OBJECT_CLASS (parent_class)->dispose (object);
542 * @name: the name of the new bin
544 * Creates a new bin with the given name.
546 * Returns: (transfer floating): a new #GstBin
549 gst_bin_new (const gchar * name)
551 return gst_element_factory_make ("bin", name);
555 gst_bin_set_property (GObject * object, guint prop_id,
556 const GValue * value, GParamSpec * pspec)
560 gstbin = GST_BIN_CAST (object);
563 case PROP_ASYNC_HANDLING:
564 GST_OBJECT_LOCK (gstbin);
565 gstbin->priv->asynchandling = g_value_get_boolean (value);
566 GST_OBJECT_UNLOCK (gstbin);
568 case PROP_MESSAGE_FORWARD:
569 GST_OBJECT_LOCK (gstbin);
570 gstbin->priv->message_forward = g_value_get_boolean (value);
571 GST_OBJECT_UNLOCK (gstbin);
574 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
580 gst_bin_get_property (GObject * object, guint prop_id,
581 GValue * value, GParamSpec * pspec)
585 gstbin = GST_BIN_CAST (object);
588 case PROP_ASYNC_HANDLING:
589 GST_OBJECT_LOCK (gstbin);
590 g_value_set_boolean (value, gstbin->priv->asynchandling);
591 GST_OBJECT_UNLOCK (gstbin);
593 case PROP_MESSAGE_FORWARD:
594 GST_OBJECT_LOCK (gstbin);
595 g_value_set_boolean (value, gstbin->priv->message_forward);
596 GST_OBJECT_UNLOCK (gstbin);
599 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
605 /* return the cached index */
607 gst_bin_get_index_func (GstElement * element)
612 bin = GST_BIN_CAST (element);
614 GST_OBJECT_LOCK (bin);
615 if ((result = bin->priv->index))
616 gst_object_ref (result);
617 GST_OBJECT_UNLOCK (bin);
622 /* set the index on all elements in this bin
627 gst_bin_set_index_func (GstElement * element, GstIndex * index)
633 GValue data = { 0, };
635 bin = GST_BIN_CAST (element);
637 GST_OBJECT_LOCK (bin);
638 old = bin->priv->index;
639 if (G_UNLIKELY (old == index))
642 gst_object_ref (index);
643 bin->priv->index = index;
644 GST_OBJECT_UNLOCK (bin);
647 gst_object_unref (old);
649 it = gst_bin_iterate_elements (bin);
651 /* set the index on all elements in the bin */
654 switch (gst_iterator_next (it, &data)) {
655 case GST_ITERATOR_OK:
657 GstElement *child = g_value_get_object (&data);
659 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
660 GST_ELEMENT_NAME (child));
661 gst_element_set_index (child, index);
663 g_value_reset (&data);
666 case GST_ITERATOR_RESYNC:
667 GST_DEBUG_OBJECT (bin, "iterator doing resync");
668 gst_iterator_resync (it);
671 case GST_ITERATOR_DONE:
672 GST_DEBUG_OBJECT (bin, "iterator done");
677 g_value_unset (&data);
678 gst_iterator_free (it);
683 GST_DEBUG_OBJECT (bin, "index was already set");
684 GST_OBJECT_UNLOCK (bin);
690 /* set the clock on all elements in this bin
695 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
701 GValue data = { 0, };
703 bin = GST_BIN_CAST (element);
705 it = gst_bin_iterate_elements (bin);
709 switch (gst_iterator_next (it, &data)) {
710 case GST_ITERATOR_OK:
712 GstElement *child = g_value_get_object (&data);
714 res &= gst_element_set_clock (child, clock);
716 g_value_reset (&data);
719 case GST_ITERATOR_RESYNC:
720 GST_DEBUG_OBJECT (bin, "iterator doing resync");
721 gst_iterator_resync (it);
725 case GST_ITERATOR_DONE:
726 GST_DEBUG_OBJECT (bin, "iterator done");
731 g_value_unset (&data);
732 gst_iterator_free (it);
735 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
740 /* get the clock for this bin by asking all of the children in this bin
742 * The ref of the returned clock in increased so unref after usage.
744 * We loop the elements in state order and pick the last clock we can
745 * get. This makes sure we get a clock from the source.
750 gst_bin_provide_clock_func (GstElement * element)
752 GstClock *result = NULL;
753 GstElement *provider = NULL;
758 GstClock **provided_clock_p;
759 GstElement **clock_provider_p;
761 bin = GST_BIN_CAST (element);
763 GST_OBJECT_LOCK (bin);
764 if (!bin->clock_dirty)
767 GST_DEBUG_OBJECT (bin, "finding new clock");
769 it = gst_bin_sort_iterator_new (bin);
770 GST_OBJECT_UNLOCK (bin);
774 switch (gst_iterator_next (it, &val)) {
775 case GST_ITERATOR_OK:
777 GstElement *child = g_value_get_object (&val);
780 clock = gst_element_provide_clock (child);
782 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
783 clock, GST_ELEMENT_NAME (child));
785 gst_object_unref (result);
786 gst_object_unref (provider);
789 provider = gst_object_ref (child);
792 g_value_reset (&val);
795 case GST_ITERATOR_RESYNC:
796 gst_iterator_resync (it);
799 case GST_ITERATOR_DONE:
804 g_value_unset (&val);
805 gst_iterator_free (it);
807 GST_OBJECT_LOCK (bin);
808 if (!bin->clock_dirty) {
810 gst_object_unref (provider);
812 gst_object_unref (result);
818 provided_clock_p = &bin->provided_clock;
819 clock_provider_p = &bin->clock_provider;
820 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
821 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
822 bin->clock_dirty = FALSE;
823 GST_DEBUG_OBJECT (bin,
824 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
826 /* Provider is not being returned to caller, just the result */
828 gst_object_unref (provider);
829 GST_OBJECT_UNLOCK (bin);
835 if ((result = bin->provided_clock))
836 gst_object_ref (result);
837 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
838 GST_OBJECT_UNLOCK (bin);
845 * functions for manipulating cached messages
850 GstMessageType types;
853 /* check if a message is of given src and type */
855 message_check (GstMessage * message, MessageFind * target)
860 eq &= GST_MESSAGE_SRC (message) == target->src;
862 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
863 GST_LOG ("looking at message %p: %d", message, eq);
869 find_message (GstBin * bin, GstObject * src, GstMessageType types)
877 result = g_list_find_custom (bin->messages, &find,
878 (GCompareFunc) message_check);
881 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
882 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
885 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
886 #ifndef GST_DISABLE_GST_DEBUG
890 for (i = 0; i < 32; i++)
891 if (types & (1 << i))
892 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
900 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
903 * A message that is cached and has the same SRC and type is replaced
904 * by the given message.
907 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
913 if ((src = GST_MESSAGE_SRC (message))) {
914 /* first find the previous message posted by this element */
915 if ((previous = find_message (bin, src, types))) {
916 GstMessage *previous_msg;
918 /* if we found a previous message, replace it */
919 previous_msg = previous->data;
920 previous->data = message;
922 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
923 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
924 GST_MESSAGE_TYPE_NAME (message));
926 gst_message_unref (previous_msg);
928 /* keep new message */
929 bin->messages = g_list_prepend (bin->messages, message);
931 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
932 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
935 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
936 GST_MESSAGE_TYPE_NAME (message));
938 gst_message_unref (message);
943 /* with LOCK. Remove all messages of given types */
945 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
953 for (walk = bin->messages; walk; walk = next) {
954 GstMessage *message = (GstMessage *) walk->data;
956 next = g_list_next (walk);
958 if (message_check (message, &find) == 0) {
959 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
960 "deleting message %p of types 0x%08x", message, types);
961 bin->messages = g_list_delete_link (bin->messages, walk);
962 gst_message_unref (message);
964 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
965 "not deleting message %p of type 0x%08x", message,
966 GST_MESSAGE_TYPE (message));
972 /* Check if the bin is EOS. We do this by scanning all sinks and
973 * checking if they posted an EOS message.
975 * call with bin LOCK */
977 is_eos (GstBin * bin, guint32 * seqnum)
984 for (walk = bin->children; walk; walk = g_list_next (walk)) {
987 element = GST_ELEMENT_CAST (walk->data);
988 if (bin_element_is_sink (element, bin) == 0) {
989 /* check if element posted EOS */
991 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
992 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
993 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
996 GST_DEBUG ("sink '%s' did not post EOS yet",
997 GST_ELEMENT_NAME (element));
1003 /* FIXME: Some tests (e.g. elements/capsfilter) use
1004 * pipelines with a dangling sinkpad but no sink element.
1005 * These tests assume that no EOS message is ever
1006 * posted on the bus so let's keep that behaviour.
1007 * In valid pipelines this doesn't make a difference.
1009 return result && n_eos > 0;
1013 unlink_pads (const GValue * item, gpointer user_data)
1018 pad = g_value_get_object (item);
1020 if ((peer = gst_pad_get_peer (pad))) {
1021 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1022 gst_pad_unlink (pad, peer);
1024 gst_pad_unlink (peer, pad);
1025 gst_object_unref (peer);
1029 /* vmethod that adds an element to a bin
1034 gst_bin_add_func (GstBin * bin, GstElement * element)
1038 gboolean is_sink, is_source, provides_clock, requires_clock;
1039 GstMessage *clock_message = NULL, *async_message = NULL;
1040 GstStateChangeReturn ret;
1042 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1044 /* we obviously can't add ourself to ourself */
1045 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1048 /* get the element name to make sure it is unique in this bin. */
1049 GST_OBJECT_LOCK (element);
1050 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1051 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1052 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1054 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1056 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1057 GST_OBJECT_UNLOCK (element);
1059 GST_OBJECT_LOCK (bin);
1061 /* then check to see if the element's name is already taken in the bin,
1062 * we can safely take the lock here. This check is probably bogus because
1063 * you can safely change the element name after this check and before setting
1064 * the object parent. The window is very small though... */
1065 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1066 goto duplicate_name;
1068 /* set the element's parent and add the element to the bin's list of children */
1069 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1070 GST_OBJECT_CAST (bin))))
1073 /* if we add a sink we become a sink */
1075 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1077 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1080 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1082 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1084 if (provides_clock) {
1085 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1087 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1088 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1090 if (requires_clock) {
1091 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1092 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1095 bin->children = g_list_prepend (bin->children, element);
1097 bin->children_cookie++;
1098 bin->priv->structure_cookie++;
1100 /* distribute the bus */
1101 gst_element_set_bus (element, bin->child_bus);
1103 /* propagate the current base_time, start_time and clock */
1104 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1105 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1106 /* it's possible that the element did not accept the clock but
1107 * that is not important right now. When the pipeline goes to PLAYING,
1108 * a new clock will be selected */
1109 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1112 /* set the cached index on the children */
1113 if (bin->priv->index)
1114 gst_element_set_index (element, bin->priv->index);
1117 ret = GST_STATE_RETURN (bin);
1118 /* no need to update the state if we are in error */
1119 if (ret == GST_STATE_CHANGE_FAILURE)
1120 goto no_state_recalc;
1122 /* update the bin state, the new element could have been an ASYNC or
1123 * NO_PREROLL element */
1124 ret = GST_STATE_RETURN (element);
1125 GST_DEBUG_OBJECT (bin, "added %s element",
1126 gst_element_state_change_return_get_name (ret));
1129 case GST_STATE_CHANGE_ASYNC:
1131 /* create message to track this aync element when it posts an async-done
1133 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1136 case GST_STATE_CHANGE_NO_PREROLL:
1137 /* ignore all async elements we might have and commit our state */
1138 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1140 case GST_STATE_CHANGE_FAILURE:
1147 GST_OBJECT_UNLOCK (bin);
1149 /* post the messages on the bus of the element so that the bin can handle
1152 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1155 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1157 /* unlink all linked pads */
1158 it = gst_element_iterate_pads (element);
1159 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1160 gst_iterator_free (it);
1162 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1165 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1166 gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
1173 /* ERROR handling here */
1176 GST_OBJECT_LOCK (bin);
1177 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1178 GST_OBJECT_UNLOCK (bin);
1183 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1184 elem_name, GST_ELEMENT_NAME (bin));
1185 GST_OBJECT_UNLOCK (bin);
1191 g_warning ("Element '%s' already has parent", elem_name);
1192 GST_OBJECT_UNLOCK (bin);
1201 * @element: (transfer full): the #GstElement to add
1203 * Adds the given element to the bin. Sets the element's parent, and thus
1204 * takes ownership of the element. An element can only be added to one bin.
1206 * If the element's pads are linked to other pads, the pads will be unlinked
1207 * before the element is added to the bin.
1210 * When you add an element to an already-running pipeline, you will have to
1211 * take care to set the state of the newly-added element to the desired
1212 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1213 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1214 * The bin or pipeline will not take care of this for you.
1219 * Returns: TRUE if the element could be added, FALSE if
1220 * the bin does not want to accept the element.
1223 gst_bin_add (GstBin * bin, GstElement * element)
1225 GstBinClass *bclass;
1228 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1229 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1231 bclass = GST_BIN_GET_CLASS (bin);
1233 if (G_UNLIKELY (bclass->add_element == NULL))
1236 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1237 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1238 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1240 result = bclass->add_element (bin, element);
1244 /* ERROR handling */
1247 g_warning ("adding elements to bin '%s' is not supported",
1248 GST_ELEMENT_NAME (bin));
1253 /* remove an element from the bin
1258 gst_bin_remove_func (GstBin * bin, GstElement * element)
1262 gboolean is_sink, is_source, provides_clock, requires_clock;
1263 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1264 GstMessage *clock_message = NULL;
1265 GstClock **provided_clock_p;
1266 GstElement **clock_provider_p;
1268 gboolean other_async, this_async, have_no_preroll;
1269 GstStateChangeReturn ret;
1271 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1273 GST_OBJECT_LOCK (bin);
1275 GST_OBJECT_LOCK (element);
1276 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1278 if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
1281 /* remove the parent ref */
1282 GST_OBJECT_PARENT (element) = NULL;
1284 /* grab element name so we can print it */
1285 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1286 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1288 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1290 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1291 GST_OBJECT_UNLOCK (element);
1295 othersource = FALSE;
1296 otherprovider = FALSE;
1297 otherrequirer = FALSE;
1298 have_no_preroll = FALSE;
1299 /* iterate the elements, we collect which ones are async and no_preroll. We
1300 * also remove the element when we find it. */
1301 for (walk = bin->children; walk; walk = next) {
1302 GstElement *child = GST_ELEMENT_CAST (walk->data);
1304 next = g_list_next (walk);
1306 if (child == element) {
1308 /* remove the element */
1309 bin->children = g_list_delete_link (bin->children, walk);
1311 gboolean child_sink, child_source, child_provider, child_requirer;
1313 GST_OBJECT_LOCK (child);
1314 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1315 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1317 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1319 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1320 /* when we remove a sink, check if there are other sinks. */
1321 if (is_sink && !othersink && child_sink)
1323 if (is_source && !othersource && child_source)
1325 if (provides_clock && !otherprovider && child_provider)
1326 otherprovider = TRUE;
1327 if (requires_clock && !otherrequirer && child_requirer)
1328 otherrequirer = TRUE;
1329 /* check if we have NO_PREROLL children */
1330 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1331 have_no_preroll = TRUE;
1332 GST_OBJECT_UNLOCK (child);
1336 /* the element must have been in the bin's list of children */
1337 if (G_UNLIKELY (!found))
1340 /* we now removed the element from the list of elements, increment the cookie
1341 * so that others can detect a change in the children list. */
1343 bin->children_cookie++;
1344 bin->priv->structure_cookie++;
1346 if (is_sink && !othersink) {
1347 /* we're not a sink anymore */
1348 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1349 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1351 if (is_source && !othersource) {
1352 /* we're not a source anymore */
1353 GST_DEBUG_OBJECT (bin, "we removed the last source");
1354 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1356 if (provides_clock && !otherprovider) {
1357 /* we're not a clock provider anymore */
1358 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1359 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1361 if (requires_clock && !otherrequirer) {
1362 /* we're not a clock requirer anymore */
1363 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1364 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1367 /* if the clock provider for this element is removed, we lost
1368 * the clock as well, we need to inform the parent of this
1369 * so that it can select a new clock */
1370 if (bin->clock_provider == element) {
1371 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1372 bin->clock_dirty = TRUE;
1374 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1375 provided_clock_p = &bin->provided_clock;
1376 clock_provider_p = &bin->clock_provider;
1377 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1378 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1381 /* remove messages for the element, if there was a pending ASYNC_START
1382 * message we must see if removing the element caused the bin to lose its
1385 other_async = FALSE;
1386 for (walk = bin->messages; walk; walk = next) {
1387 GstMessage *message = (GstMessage *) walk->data;
1388 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1391 next = g_list_next (walk);
1394 switch (GST_MESSAGE_TYPE (message)) {
1395 case GST_MESSAGE_ASYNC_START:
1401 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1403 case GST_MESSAGE_STRUCTURE_CHANGE:
1407 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1409 /* it's unlikely that this message is still in the list of messages
1410 * because this would mean that a link/unlink is busy in another thread
1411 * while we remove the element. We still have to remove the message
1412 * because we might not receive the done message anymore when the element
1413 * is removed from the bin. */
1414 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1415 if (owner == element)
1426 /* delete all message types */
1427 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1428 message, elem_name);
1429 bin->messages = g_list_delete_link (bin->messages, walk);
1430 gst_message_unref (message);
1434 /* get last return */
1435 ret = GST_STATE_RETURN (bin);
1437 /* no need to update the state if we are in error */
1438 if (ret == GST_STATE_CHANGE_FAILURE)
1439 goto no_state_recalc;
1441 if (!other_async && this_async) {
1442 /* all other elements were not async and we removed the async one,
1443 * handle the async-done case because we are not async anymore now. */
1444 GST_DEBUG_OBJECT (bin,
1445 "we removed the last async element, have no_preroll %d",
1448 /* the current state return of the bin depends on if there are no_preroll
1449 * elements in the pipeline or not */
1450 if (have_no_preroll)
1451 ret = GST_STATE_CHANGE_NO_PREROLL;
1453 ret = GST_STATE_CHANGE_SUCCESS;
1455 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1457 GST_DEBUG_OBJECT (bin,
1458 "recalc state preroll: %d, other async: %d, this async %d",
1459 have_no_preroll, other_async, this_async);
1461 if (have_no_preroll) {
1462 ret = GST_STATE_CHANGE_NO_PREROLL;
1463 } else if (other_async) {
1464 /* there are other async elements and we were not doing an async state
1465 * change, change our pending state and go async */
1466 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1467 GST_STATE_NEXT (bin) = GST_STATE (bin);
1468 GST_STATE_PENDING (bin) = GST_STATE (bin);
1470 ret = GST_STATE_CHANGE_ASYNC;
1472 GST_STATE_RETURN (bin) = ret;
1476 gst_element_set_bus (element, NULL);
1477 /* Clear the clock we provided to the element */
1478 gst_element_set_clock (element, NULL);
1479 GST_OBJECT_UNLOCK (bin);
1482 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1484 /* unlink all linked pads */
1485 it = gst_element_iterate_pads (element);
1486 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1487 gst_iterator_free (it);
1489 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1492 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1493 gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
1497 /* element is really out of our control now */
1498 gst_object_unref (element);
1502 /* ERROR handling */
1505 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1506 GST_ELEMENT_NAME (bin));
1507 GST_OBJECT_UNLOCK (element);
1508 GST_OBJECT_UNLOCK (bin);
1517 * @element: (transfer none): the #GstElement to remove
1519 * Removes the element from the bin, unparenting it as well.
1520 * Unparenting the element means that the element will be dereferenced,
1521 * so if the bin holds the only reference to the element, the element
1522 * will be freed in the process of removing it from the bin. If you
1523 * want the element to still exist after removing, you need to call
1524 * gst_object_ref() before removing it from the bin.
1526 * If the element's pads are linked to other pads, the pads will be unlinked
1527 * before the element is removed from the bin.
1531 * Returns: TRUE if the element could be removed, FALSE if
1532 * the bin does not want to remove the element.
1535 gst_bin_remove (GstBin * bin, GstElement * element)
1537 GstBinClass *bclass;
1540 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1541 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1543 bclass = GST_BIN_GET_CLASS (bin);
1545 if (G_UNLIKELY (bclass->remove_element == NULL))
1548 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1549 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1551 result = bclass->remove_element (bin, element);
1555 /* ERROR handling */
1558 g_warning ("removing elements from bin '%s' is not supported",
1559 GST_ELEMENT_NAME (bin));
1565 * gst_bin_iterate_elements:
1568 * Gets an iterator for the elements in this bin.
1570 * Each element yielded by the iterator will have its refcount increased, so
1573 * MT safe. Caller owns returned value.
1575 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1578 gst_bin_iterate_elements (GstBin * bin)
1580 GstIterator *result;
1582 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1584 GST_OBJECT_LOCK (bin);
1585 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1586 GST_OBJECT_GET_LOCK (bin),
1587 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1588 GST_OBJECT_UNLOCK (bin);
1593 static GstIteratorItem
1594 iterate_child_recurse (GstIterator * it, const GValue * item)
1596 GstElement *child = g_value_get_object (item);
1598 if (GST_IS_BIN (child)) {
1599 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1601 gst_iterator_push (it, other);
1603 return GST_ITERATOR_ITEM_PASS;
1607 * gst_bin_iterate_recurse:
1610 * Gets an iterator for the elements in this bin.
1611 * This iterator recurses into GstBin children.
1613 * Each element yielded by the iterator will have its refcount increased, so
1616 * MT safe. Caller owns returned value.
1618 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1621 gst_bin_iterate_recurse (GstBin * bin)
1623 GstIterator *result;
1625 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1627 GST_OBJECT_LOCK (bin);
1628 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1629 GST_OBJECT_GET_LOCK (bin),
1630 &bin->children_cookie,
1632 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1633 GST_OBJECT_UNLOCK (bin);
1638 /* returns 0 when TRUE because this is a GCompareFunc */
1641 bin_element_is_sink (GstElement * child, GstBin * bin)
1645 /* we lock the child here for the remainder of the function to
1646 * get its name and flag safely. */
1647 GST_OBJECT_LOCK (child);
1648 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1650 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1651 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1653 GST_OBJECT_UNLOCK (child);
1654 return is_sink ? 0 : 1;
1658 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1660 GstBin *bin = g_value_get_object (vbin);
1661 GstElement *child = g_value_get_object (vchild);
1663 return (bin_element_is_sink (child, bin));
1667 * gst_bin_iterate_sinks:
1670 * Gets an iterator for all elements in the bin that have the
1671 * #GST_ELEMENT_FLAG_SINK flag set.
1673 * Each element yielded by the iterator will have its refcount increased, so
1676 * MT safe. Caller owns returned value.
1678 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1681 gst_bin_iterate_sinks (GstBin * bin)
1683 GstIterator *children;
1684 GstIterator *result;
1685 GValue vbin = { 0, };
1687 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1689 g_value_init (&vbin, GST_TYPE_BIN);
1690 g_value_set_object (&vbin, bin);
1692 children = gst_bin_iterate_elements (bin);
1693 result = gst_iterator_filter (children,
1694 (GCompareFunc) sink_iterator_filter, &vbin);
1696 g_value_unset (&vbin);
1701 /* returns 0 when TRUE because this is a GCompareFunc */
1704 bin_element_is_src (GstElement * child, GstBin * bin)
1708 /* we lock the child here for the remainder of the function to
1709 * get its name and other info safely. */
1710 GST_OBJECT_LOCK (child);
1711 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1713 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1714 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1716 GST_OBJECT_UNLOCK (child);
1717 return is_src ? 0 : 1;
1721 src_iterator_filter (const GValue * vchild, GValue * vbin)
1723 GstBin *bin = g_value_get_object (vbin);
1724 GstElement *child = g_value_get_object (vchild);
1726 return (bin_element_is_src (child, bin));
1730 * gst_bin_iterate_sources:
1733 * Gets an iterator for all elements in the bin that have the
1734 * #GST_ELEMENT_FLAG_SOURCE flag set.
1736 * Each element yielded by the iterator will have its refcount increased, so
1739 * MT safe. Caller owns returned value.
1741 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1744 gst_bin_iterate_sources (GstBin * bin)
1746 GstIterator *children;
1747 GstIterator *result;
1748 GValue vbin = { 0, };
1750 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1752 g_value_init (&vbin, GST_TYPE_BIN);
1753 g_value_set_object (&vbin, bin);
1755 children = gst_bin_iterate_elements (bin);
1756 result = gst_iterator_filter (children,
1757 (GCompareFunc) src_iterator_filter, &vbin);
1759 g_value_unset (&vbin);
1767 static GstStateChangeReturn
1768 gst_bin_get_state_func (GstElement * element, GstState * state,
1769 GstState * pending, GstClockTime timeout)
1771 GstStateChangeReturn ret;
1773 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1776 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1782 /***********************************************
1783 * Topologically sorted iterator
1784 * see http://en.wikipedia.org/wiki/Topological_sorting
1786 * For each element in the graph, an entry is kept in a HashTable
1787 * with its number of srcpad connections (degree).
1788 * We then change state of all elements without dependencies
1789 * (degree 0) and decrement the degree of all elements connected
1790 * on the sinkpads. When an element reaches degree 0, its state is
1792 * When all elements are handled the algorithm stops.
1794 typedef struct _GstBinSortIterator
1797 GQueue queue; /* elements queued for state change */
1798 GstBin *bin; /* bin we iterate */
1799 gint mode; /* adding or removing dependency */
1800 GstElement *best; /* next element with least dependencies */
1801 gint best_deg; /* best degree */
1802 GHashTable *hash; /* hashtable with element dependencies */
1803 gboolean dirty; /* we detected structure change */
1804 } GstBinSortIterator;
1807 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1808 GstBinSortIterator * copy)
1810 GHashTableIter iter;
1811 gpointer key, value;
1813 copy->queue = it->queue;
1814 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1816 copy->bin = gst_object_ref (it->bin);
1818 copy->best = gst_object_ref (it->best);
1820 copy->hash = g_hash_table_new (NULL, NULL);
1821 g_hash_table_iter_init (&iter, it->hash);
1822 while (g_hash_table_iter_next (&iter, &key, &value))
1823 g_hash_table_insert (copy->hash, key, value);
1826 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1827 #define HASH_SET_DEGREE(bit, elem, deg) \
1828 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1829 #define HASH_GET_DEGREE(bit, elem) \
1830 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1832 /* add element to queue of next elements in the iterator.
1833 * We push at the tail to give higher priority elements a
1836 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1838 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1839 GST_ELEMENT_NAME (element));
1840 gst_object_ref (element);
1841 g_queue_push_tail (&bit->queue, element);
1842 HASH_SET_DEGREE (bit, element, -1);
1846 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1850 if ((find = g_queue_find (&bit->queue, element))) {
1851 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1852 GST_ELEMENT_NAME (element));
1854 g_queue_delete_link (&bit->queue, find);
1855 gst_object_unref (element);
1857 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1858 GST_ELEMENT_NAME (element));
1862 /* clear the queue, unref all objects as we took a ref when
1863 * we added them to the queue */
1865 clear_queue (GQueue * queue)
1869 while ((p = g_queue_pop_head (queue)))
1870 gst_object_unref (p);
1873 /* set all degrees to 0. Elements marked as a sink are
1874 * added to the queue immediately. Since we only look at the SINK flag of the
1875 * element, it is possible that we add non-sinks to the queue. These will be
1876 * removed from the queue again when we can prove that it provides data for some
1879 reset_degree (GstElement * element, GstBinSortIterator * bit)
1883 /* sinks are added right away */
1884 GST_OBJECT_LOCK (element);
1885 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1886 GST_OBJECT_UNLOCK (element);
1889 add_to_queue (bit, element);
1891 /* others are marked with 0 and handled when sinks are done */
1892 HASH_SET_DEGREE (bit, element, 0);
1896 /* adjust the degree of all elements connected to the given
1897 * element. If a degree of an element drops to 0, it is
1898 * added to the queue of elements to schedule next.
1900 * We have to make sure not to cross the bin boundary this element
1904 update_degree (GstElement * element, GstBinSortIterator * bit)
1906 gboolean linked = FALSE;
1908 GST_OBJECT_LOCK (element);
1909 /* don't touch degree if element has no sinkpads */
1910 if (element->numsinkpads != 0) {
1911 /* loop over all sinkpads, decrement degree for all connected
1912 * elements in this bin */
1915 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1918 pad = GST_PAD_CAST (pads->data);
1920 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1921 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1922 GST_MESSAGE_STRUCTURE_CHANGE))) {
1923 /* mark the iterator as dirty because we won't be updating the degree
1924 * of the peer parent now. This would result in the 'loop detected'
1925 * later on because the peer parent element could become the best next
1926 * element with a degree > 0. We will simply continue our state
1927 * changes and we'll eventually resync when the unlink completed and
1928 * the iterator cookie is updated. */
1933 if ((peer = gst_pad_get_peer (pad))) {
1934 GstElement *peer_element;
1936 if ((peer_element = gst_pad_get_parent_element (peer))) {
1937 GST_OBJECT_LOCK (peer_element);
1938 /* check that we don't go outside of this bin */
1939 if (GST_OBJECT_CAST (peer_element)->parent ==
1940 GST_OBJECT_CAST (bit->bin)) {
1941 gint old_deg, new_deg;
1943 old_deg = HASH_GET_DEGREE (bit, peer_element);
1945 /* check to see if we added an element as sink that was not really a
1946 * sink because it was connected to some other element. */
1947 if (old_deg == -1) {
1948 remove_from_queue (bit, peer_element);
1951 new_deg = old_deg + bit->mode;
1953 GST_DEBUG_OBJECT (bit->bin,
1954 "change element %s, degree %d->%d, linked to %s",
1955 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1956 GST_ELEMENT_NAME (element));
1958 /* update degree, it is possible that an element was in 0 and
1959 * reaches -1 here. This would mean that the element had no sinkpads
1960 * but became linked while the state change was happening. We will
1961 * resync on this with the structure change message. */
1963 /* degree hit 0, add to queue */
1964 add_to_queue (bit, peer_element);
1966 HASH_SET_DEGREE (bit, peer_element, new_deg);
1970 GST_OBJECT_UNLOCK (peer_element);
1971 gst_object_unref (peer_element);
1973 gst_object_unref (peer);
1978 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1979 GST_ELEMENT_NAME (element));
1981 GST_OBJECT_UNLOCK (element);
1984 /* find the next best element not handled yet. This is the one
1985 * with the lowest non-negative degree */
1987 find_element (GstElement * element, GstBinSortIterator * bit)
1991 /* element is already handled */
1992 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1995 /* first element or element with smaller degree */
1996 if (bit->best == NULL || bit->best_deg > degree) {
1997 bit->best = element;
1998 bit->best_deg = degree;
2002 /* get next element in iterator. the returned element has the
2003 * refcount increased */
2004 static GstIteratorResult
2005 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2008 GstBin *bin = bit->bin;
2010 /* empty queue, we have to find a next best element */
2011 if (g_queue_is_empty (&bit->queue)) {
2013 bit->best_deg = G_MAXINT;
2014 g_list_foreach (bin->children, (GFunc) find_element, bit);
2015 if ((best = bit->best)) {
2016 /* when we detected an unlink, don't warn because our degrees might be
2017 * screwed up. We will resync later */
2018 if (bit->best_deg != 0 && !bit->dirty) {
2019 /* we don't fail on this one yet */
2020 GST_WARNING_OBJECT (bin, "loop dected in graph");
2021 g_warning ("loop detected in the graph of bin '%s'!!",
2022 GST_ELEMENT_NAME (bin));
2024 /* best unhandled element, schedule as next element */
2025 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2026 GST_ELEMENT_NAME (best));
2027 HASH_SET_DEGREE (bit, best, -1);
2028 g_value_set_object (result, best);
2030 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2031 /* no more unhandled elements, we are done */
2032 return GST_ITERATOR_DONE;
2035 /* everything added to the queue got reffed */
2036 best = g_queue_pop_head (&bit->queue);
2037 g_value_set_object (result, best);
2038 gst_object_unref (best);
2041 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2042 /* update degrees of linked elements */
2043 update_degree (best, bit);
2045 return GST_ITERATOR_OK;
2048 /* clear queues, recalculate the degrees and restart. */
2050 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2052 GstBin *bin = bit->bin;
2054 GST_DEBUG_OBJECT (bin, "resync");
2056 clear_queue (&bit->queue);
2058 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2059 /* calc degrees, incrementing */
2061 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2062 /* for the rest of the function we decrement the degrees */
2066 /* clear queues, unref bin and free iterator. */
2068 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2070 GstBin *bin = bit->bin;
2072 GST_DEBUG_OBJECT (bin, "free");
2073 clear_queue (&bit->queue);
2074 g_hash_table_destroy (bit->hash);
2075 gst_object_unref (bin);
2078 /* should be called with the bin LOCK held */
2079 static GstIterator *
2080 gst_bin_sort_iterator_new (GstBin * bin)
2082 GstBinSortIterator *result;
2084 /* we don't need an ItemFunction because we ref the items in the _next
2086 result = (GstBinSortIterator *)
2087 gst_iterator_new (sizeof (GstBinSortIterator),
2089 GST_OBJECT_GET_LOCK (bin),
2090 &bin->priv->structure_cookie,
2091 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2092 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2093 (GstIteratorItemFunction) NULL,
2094 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2095 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2096 g_queue_init (&result->queue);
2097 result->hash = g_hash_table_new (NULL, NULL);
2098 gst_object_ref (bin);
2100 gst_bin_sort_iterator_resync (result);
2102 return (GstIterator *) result;
2106 * gst_bin_iterate_sorted:
2109 * Gets an iterator for the elements in this bin in topologically
2110 * sorted order. This means that the elements are returned from
2111 * the most downstream elements (sinks) to the sources.
2113 * This function is used internally to perform the state changes
2114 * of the bin elements and for clock selection.
2116 * Each element yielded by the iterator will have its refcount increased, so
2119 * MT safe. Caller owns returned value.
2121 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2124 gst_bin_iterate_sorted (GstBin * bin)
2126 GstIterator *result;
2128 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2130 GST_OBJECT_LOCK (bin);
2131 result = gst_bin_sort_iterator_new (bin);
2132 GST_OBJECT_UNLOCK (bin);
2137 static GstStateChangeReturn
2138 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2139 GstClockTime base_time, GstClockTime start_time, GstState current,
2142 GstStateChangeReturn ret;
2143 GstState child_current, child_pending;
2147 GST_STATE_LOCK (element);
2149 GST_OBJECT_LOCK (element);
2150 /* set base_time and start time on child */
2151 GST_ELEMENT_START_TIME (element) = start_time;
2152 element->base_time = base_time;
2153 /* peel off the locked flag */
2154 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2155 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2156 ret = GST_STATE_RETURN (element);
2157 child_current = GST_STATE (element);
2158 child_pending = GST_STATE_PENDING (element);
2159 GST_OBJECT_UNLOCK (element);
2161 /* skip locked elements */
2162 if (G_UNLIKELY (locked))
2165 /* if the element was no preroll, just start changing the state regardless
2166 * if it had async elements (in the case of a bin) because they won't preroll
2168 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2169 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2173 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2174 "current %s pending %s, desired next %s",
2175 gst_element_state_get_name (child_current),
2176 gst_element_state_get_name (child_pending),
2177 gst_element_state_get_name (next));
2179 /* always recurse into bins so that we can set the base time */
2180 if (GST_IS_BIN (element))
2183 /* Try not to change the state of elements that are already in the state we're
2185 if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
2186 /* child is already at the requested state, return previous return. Note that
2187 * if the child has a pending state to next, we will still call the
2188 * set_state function */
2190 } else if (next > current) {
2191 /* upward state change */
2192 if (child_pending == GST_STATE_VOID_PENDING) {
2193 /* .. and the child is not busy doing anything */
2194 if (child_current > next) {
2195 /* .. and is already past the requested state, assume it got there
2197 ret = GST_STATE_CHANGE_SUCCESS;
2200 } else if (child_pending > child_current) {
2201 /* .. and the child is busy going upwards */
2202 if (child_current >= next) {
2203 /* .. and is already past the requested state, assume it got there
2205 ret = GST_STATE_CHANGE_SUCCESS;
2209 /* .. and the child is busy going downwards */
2210 if (child_current > next) {
2211 /* .. and is already past the requested state, assume it got there
2213 ret = GST_STATE_CHANGE_SUCCESS;
2217 } else if (next < current) {
2218 /* downward state change */
2219 if (child_pending == GST_STATE_VOID_PENDING) {
2220 /* .. and the child is not busy doing anything */
2221 if (child_current < next) {
2222 /* .. and is already past the requested state, assume it got there
2224 ret = GST_STATE_CHANGE_SUCCESS;
2227 } else if (child_pending < child_current) {
2228 /* .. and the child is busy going downwards */
2229 if (child_current <= next) {
2230 /* .. and is already past the requested state, assume it got there
2232 ret = GST_STATE_CHANGE_SUCCESS;
2236 /* .. and the child is busy going upwards */
2237 if (child_current < next) {
2238 /* .. and is already past the requested state, assume it got there
2240 ret = GST_STATE_CHANGE_SUCCESS;
2247 GST_OBJECT_LOCK (bin);
2248 /* the element was busy with an upwards async state change, we must wait for
2249 * an ASYNC_DONE message before we attemp to change the state. */
2251 find_message (bin, GST_OBJECT_CAST (element),
2252 GST_MESSAGE_ASYNC_START))) {
2253 #ifndef GST_DISABLE_GST_DEBUG
2254 GstMessage *message = GST_MESSAGE_CAST (found->data);
2256 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2257 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2259 /* only wait for upward state changes */
2260 if (next > current) {
2261 /* We found an async element check if we can force its state to change or
2262 * if we have to wait for it to preroll. */
2266 GST_OBJECT_UNLOCK (bin);
2269 GST_DEBUG_OBJECT (bin,
2270 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2271 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2272 GST_TIME_ARGS (base_time));
2275 ret = gst_element_set_state (element, next);
2277 GST_STATE_UNLOCK (element);
2283 GST_DEBUG_OBJECT (element,
2284 "element is locked, return previous return %s",
2285 gst_element_state_change_return_get_name (ret));
2286 GST_STATE_UNLOCK (element);
2291 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2292 "skipping transition from %s to %s",
2293 gst_element_state_get_name (child_current),
2294 gst_element_state_get_name (next));
2295 GST_STATE_UNLOCK (element);
2300 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2301 GST_OBJECT_UNLOCK (bin);
2302 GST_STATE_UNLOCK (element);
2303 return GST_STATE_CHANGE_ASYNC;
2307 /* gst_iterator_fold functions for pads_activate
2308 * Stop the iterator if activating one pad failed. */
2310 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2312 GstPad *pad = g_value_get_object (vpad);
2313 gboolean cont = TRUE;
2315 if (!(cont = gst_pad_set_active (pad, *active)))
2316 g_value_set_boolean (ret, FALSE);
2321 /* returns false on error or early cutout of the fold, true if all
2322 * pads in @iter were (de)activated successfully. */
2324 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2326 GstIteratorResult ires;
2329 /* no need to unset this later, it's just a boolean */
2330 g_value_init (&ret, G_TYPE_BOOLEAN);
2331 g_value_set_boolean (&ret, TRUE);
2334 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2337 case GST_ITERATOR_RESYNC:
2338 /* need to reset the result again */
2339 g_value_set_boolean (&ret, TRUE);
2340 gst_iterator_resync (iter);
2342 case GST_ITERATOR_DONE:
2343 /* all pads iterated, return collected value */
2346 /* iterator returned _ERROR or premature end with _OK,
2347 * mark an error and exit */
2348 g_value_set_boolean (&ret, FALSE);
2353 /* return collected value */
2354 return g_value_get_boolean (&ret);
2357 /* is called with STATE_LOCK
2360 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2365 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2367 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2368 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2369 gst_iterator_free (iter);
2370 if (G_UNLIKELY (!fold_ok))
2373 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2380 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2386 * gst_bin_recalculate_latency:
2389 * Query @bin for the current latency using and reconfigures this latency to all the
2390 * elements with a LATENCY event.
2392 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2393 * is posted on the bus.
2395 * This function simply emits the 'do-latency' signal so any custom latency
2396 * calculations will be performed.
2398 * Returns: %TRUE if the latency could be queried and reconfigured.
2403 gst_bin_recalculate_latency (GstBin * bin)
2407 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2408 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2414 gst_bin_do_latency_func (GstBin * bin)
2417 GstElement *element;
2418 GstClockTime min_latency, max_latency;
2421 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2423 element = GST_ELEMENT_CAST (bin);
2425 GST_DEBUG_OBJECT (element, "querying latency");
2427 query = gst_query_new_latency ();
2428 if ((res = gst_element_query (element, query))) {
2431 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2433 GST_DEBUG_OBJECT (element,
2434 "got min latency %" GST_TIME_FORMAT ", max latency %"
2435 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2436 GST_TIME_ARGS (max_latency), live);
2438 if (max_latency < min_latency) {
2439 /* this is an impossible situation, some parts of the pipeline might not
2440 * work correctly. We post a warning for now. */
2441 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2442 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2443 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2444 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2447 /* configure latency on elements */
2448 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2450 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2451 GST_TIME_ARGS (min_latency));
2453 GST_WARNING_OBJECT (element,
2454 "did not really configure latency of %" GST_TIME_FORMAT,
2455 GST_TIME_ARGS (min_latency));
2458 /* this is not a real problem, we just don't configure any latency. */
2459 GST_WARNING_OBJECT (element, "failed to query latency");
2461 gst_query_unref (query);
2467 gst_bin_state_changed (GstElement * element, GstState oldstate,
2468 GstState newstate, GstState pending)
2470 GstElementClass *pklass = (GstElementClass *) parent_class;
2472 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2473 bin_do_eos (GST_BIN_CAST (element));
2475 if (pklass->state_changed)
2476 pklass->state_changed (element, oldstate, newstate, pending);
2479 static GstStateChangeReturn
2480 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2483 GstStateChangeReturn ret;
2484 GstState current, next;
2485 gboolean have_async;
2486 gboolean have_no_preroll;
2487 GstClockTime base_time, start_time;
2490 GValue data = { 0, };
2492 /* we don't need to take the STATE_LOCK, it is already taken */
2493 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2494 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2496 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2497 "changing state of children from %s to %s",
2498 gst_element_state_get_name (current), gst_element_state_get_name (next));
2500 bin = GST_BIN_CAST (element);
2503 case GST_STATE_PLAYING:
2507 GST_OBJECT_LOCK (bin);
2508 toplevel = BIN_IS_TOPLEVEL (bin);
2509 GST_OBJECT_UNLOCK (bin);
2512 gst_bin_recalculate_latency (bin);
2515 case GST_STATE_PAUSED:
2516 /* Clear EOS list on next PAUSED */
2517 GST_OBJECT_LOCK (bin);
2518 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2519 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2520 bin->priv->posted_eos = FALSE;
2521 GST_OBJECT_UNLOCK (bin);
2522 if (current == GST_STATE_READY)
2523 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2524 goto activate_failure;
2526 case GST_STATE_READY:
2527 /* Clear message list on next READY */
2528 GST_OBJECT_LOCK (bin);
2529 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2530 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2531 GST_OBJECT_UNLOCK (bin);
2532 if (current == GST_STATE_PAUSED)
2533 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2534 goto activate_failure;
2536 case GST_STATE_NULL:
2537 if (current == GST_STATE_READY)
2538 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2539 goto activate_failure;
2545 /* this flag is used to make the async state changes return immediately. We
2546 * don't want them to interfere with this state change */
2547 GST_OBJECT_LOCK (bin);
2548 bin->polling = TRUE;
2549 GST_OBJECT_UNLOCK (bin);
2551 /* iterate in state change order */
2552 it = gst_bin_iterate_sorted (bin);
2554 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2555 * Note how we don't reset this value when a resync happens, the reason being
2556 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2557 * even after a resync when the async element is gone */
2561 /* take base_time */
2562 base_time = gst_element_get_base_time (element);
2563 start_time = gst_element_get_start_time (element);
2565 have_no_preroll = FALSE;
2569 switch (gst_iterator_next (it, &data)) {
2570 case GST_ITERATOR_OK:
2574 child = g_value_get_object (&data);
2576 /* set state and base_time now */
2577 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2581 case GST_STATE_CHANGE_SUCCESS:
2582 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2583 "child '%s' changed state to %d(%s) successfully",
2584 GST_ELEMENT_NAME (child), next,
2585 gst_element_state_get_name (next));
2587 case GST_STATE_CHANGE_ASYNC:
2589 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2590 "child '%s' is changing state asynchronously to %s",
2591 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2595 case GST_STATE_CHANGE_FAILURE:{
2598 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2599 "child '%s' failed to go to state %d(%s)",
2600 GST_ELEMENT_NAME (child),
2601 next, gst_element_state_get_name (next));
2603 /* Only fail if the child is still inside
2604 * this bin. It might've been removed already
2605 * because of the error by the bin subclass
2606 * to ignore the error. */
2607 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2608 if (parent == GST_OBJECT_CAST (element)) {
2609 /* element is still in bin, really error now */
2610 gst_object_unref (parent);
2613 /* child removed from bin, let the resync code redo the state
2615 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2616 "child '%s' was removed from the bin",
2617 GST_ELEMENT_NAME (child));
2620 gst_object_unref (parent);
2624 case GST_STATE_CHANGE_NO_PREROLL:
2625 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2626 "child '%s' changed state to %d(%s) successfully without preroll",
2627 GST_ELEMENT_NAME (child), next,
2628 gst_element_state_get_name (next));
2629 have_no_preroll = TRUE;
2632 g_assert_not_reached ();
2635 g_value_reset (&data);
2638 case GST_ITERATOR_RESYNC:
2639 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2640 gst_iterator_resync (it);
2643 case GST_ITERATOR_DONE:
2644 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2650 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2651 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2654 if (have_no_preroll) {
2655 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2656 "we have NO_PREROLL elements %s -> NO_PREROLL",
2657 gst_element_state_change_return_get_name (ret));
2658 ret = GST_STATE_CHANGE_NO_PREROLL;
2659 } else if (have_async) {
2660 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2661 "we have ASYNC elements %s -> ASYNC",
2662 gst_element_state_change_return_get_name (ret));
2663 ret = GST_STATE_CHANGE_ASYNC;
2667 g_value_unset (&data);
2668 gst_iterator_free (it);
2670 GST_OBJECT_LOCK (bin);
2671 bin->polling = FALSE;
2672 /* it's possible that we did not get ASYNC from the children while the bin is
2673 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2674 * itself as the source. In that case we still want to check if the state
2675 * change completed. */
2676 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2677 /* no element returned ASYNC and there are no pending async_done messages,
2678 * we can just complete. */
2679 GST_DEBUG_OBJECT (bin, "no async elements");
2682 /* when we get here an ASYNC element was found */
2683 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2684 /* we ignore ASYNC state changes when we go to READY or NULL */
2685 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2686 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2690 GST_DEBUG_OBJECT (bin, "check async elements");
2691 /* check if all elements managed to commit their state already */
2692 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2693 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2694 * all the elements commited their state while we were doing the state
2695 * change. We will still return ASYNC for consistency but we commit the
2696 * state already so that a _get_state() will return immediately. */
2697 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2699 GST_DEBUG_OBJECT (bin, "async elements commited");
2700 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
2701 GST_CLOCK_TIME_NONE);
2705 bin->priv->pending_async_done = FALSE;
2706 GST_OBJECT_UNLOCK (bin);
2708 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2709 "done changing bin's state from %s to %s, now in %s, ret %s",
2710 gst_element_state_get_name (current),
2711 gst_element_state_get_name (next),
2712 gst_element_state_get_name (GST_STATE (element)),
2713 gst_element_state_change_return_get_name (ret));
2720 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2721 "failure (de)activating src pads");
2722 return GST_STATE_CHANGE_FAILURE;
2727 * This function is a utility event handler for seek events.
2728 * It will send the event to all sinks or sources depending on the
2731 * Applications are free to override this behaviour and
2732 * implement their own seek handler, but this will work for
2733 * pretty much all cases in practice.
2736 gst_bin_send_event (GstElement * element, GstEvent * event)
2738 GstBin *bin = GST_BIN_CAST (element);
2740 gboolean res = TRUE;
2741 gboolean done = FALSE;
2742 GValue data = { 0, };
2744 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2745 iter = gst_bin_iterate_sources (bin);
2746 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2747 GST_EVENT_TYPE_NAME (event));
2749 iter = gst_bin_iterate_sinks (bin);
2750 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2751 GST_EVENT_TYPE_NAME (event));
2755 switch (gst_iterator_next (iter, &data)) {
2756 case GST_ITERATOR_OK:
2758 GstElement *child = g_value_get_object (&data);;
2760 gst_event_ref (event);
2761 res &= gst_element_send_event (child, event);
2762 GST_LOG_OBJECT (child, "After handling %s event: %d",
2763 GST_EVENT_TYPE_NAME (event), res);
2766 case GST_ITERATOR_RESYNC:
2767 gst_iterator_resync (iter);
2770 case GST_ITERATOR_DONE:
2773 case GST_ITERATOR_ERROR:
2774 g_assert_not_reached ();
2778 g_value_unset (&data);
2779 gst_iterator_free (iter);
2780 gst_event_unref (event);
2785 /* this is the function called by the threadpool. When async elements commit
2786 * their state, this function will attempt to bring the bin to the next state.
2789 gst_bin_continue_func (BinContinueData * data)
2792 GstState current, next, pending;
2793 GstStateChange transition;
2796 pending = data->pending;
2798 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2799 GST_STATE_LOCK (bin);
2801 GST_DEBUG_OBJECT (bin, "doing state continue");
2802 GST_OBJECT_LOCK (bin);
2804 /* if a new state change happened after this thread was scheduled, we return
2806 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2809 current = GST_STATE (bin);
2810 next = GST_STATE_GET_NEXT (current, pending);
2811 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2813 GST_STATE_NEXT (bin) = next;
2814 GST_STATE_PENDING (bin) = pending;
2816 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2817 GST_OBJECT_UNLOCK (bin);
2819 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2820 "continue state change %s to %s, final %s",
2821 gst_element_state_get_name (current),
2822 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2824 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2826 GST_STATE_UNLOCK (bin);
2827 GST_DEBUG_OBJECT (bin, "state continue done");
2829 gst_object_unref (bin);
2830 g_slice_free (BinContinueData, data);
2835 GST_OBJECT_UNLOCK (bin);
2836 GST_STATE_UNLOCK (bin);
2837 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2838 gst_object_unref (bin);
2839 g_slice_free (BinContinueData, data);
2844 static GstBusSyncReply
2845 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2847 GstBinClass *bclass;
2849 bclass = GST_BIN_GET_CLASS (bin);
2850 if (bclass->handle_message)
2851 bclass->handle_message (bin, message);
2853 gst_message_unref (message);
2855 return GST_BUS_DROP;
2859 bin_push_state_continue (BinContinueData * data)
2866 klass = GST_BIN_GET_CLASS (bin);
2868 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2869 g_thread_pool_push (klass->pool, data, NULL);
2872 /* an element started an async state change, if we were not busy with a state
2873 * change, we perform a lost state.
2874 * This function is called with the OBJECT lock.
2877 bin_handle_async_start (GstBin * bin)
2879 GstState old_state, new_state;
2881 GstMessage *amessage = NULL;
2883 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2886 /* get our toplevel state */
2887 toplevel = BIN_IS_TOPLEVEL (bin);
2889 /* prepare an ASYNC_START message, we always post the start message even if we
2890 * are busy with a state change or when we are NO_PREROLL. */
2892 /* non toplevel bin, prepare async-start for the parent */
2893 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
2895 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2898 /* async starts are ignored when we are NO_PREROLL */
2899 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2900 goto was_no_preroll;
2902 old_state = GST_STATE (bin);
2904 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2905 * PLAYING after optionally redistributing the base_time. */
2906 if (old_state > GST_STATE_PAUSED)
2907 new_state = GST_STATE_PAUSED;
2909 new_state = old_state;
2911 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2912 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2913 gst_element_state_get_name (new_state));
2915 GST_STATE (bin) = new_state;
2916 GST_STATE_NEXT (bin) = new_state;
2917 GST_STATE_PENDING (bin) = new_state;
2918 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2919 GST_OBJECT_UNLOCK (bin);
2922 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2927 /* post our ASYNC_START. */
2928 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2929 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2931 GST_OBJECT_LOCK (bin);
2937 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2942 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2943 GST_OBJECT_UNLOCK (bin);
2948 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2949 GST_OBJECT_UNLOCK (bin);
2954 /* this function is called when there are no more async elements in the bin. We
2955 * post a state changed message and an ASYNC_DONE message.
2956 * This function is called with the OBJECT lock.
2959 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2960 gboolean flag_pending, GstClockTime running_time)
2962 GstState current, pending, target;
2963 GstStateChangeReturn old_ret;
2964 GstState old_state, old_next;
2965 gboolean toplevel, state_changed = FALSE;
2966 GstMessage *amessage = NULL;
2967 BinContinueData *cont = NULL;
2969 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2972 pending = GST_STATE_PENDING (bin);
2977 /* check if there is something to commit */
2978 if (pending == GST_STATE_VOID_PENDING)
2979 goto nothing_pending;
2981 old_ret = GST_STATE_RETURN (bin);
2982 GST_STATE_RETURN (bin) = ret;
2984 /* move to the next target state */
2985 target = GST_STATE_TARGET (bin);
2986 pending = GST_STATE_PENDING (bin) = target;
2988 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
2990 old_state = GST_STATE (bin);
2991 /* this is the state we should go to next */
2992 old_next = GST_STATE_NEXT (bin);
2994 if (old_next != GST_STATE_PLAYING) {
2995 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2996 "committing state from %s to %s, old pending %s",
2997 gst_element_state_get_name (old_state),
2998 gst_element_state_get_name (old_next),
2999 gst_element_state_get_name (pending));
3001 /* update current state */
3002 current = GST_STATE (bin) = old_next;
3004 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3005 "setting state from %s to %s, pending %s",
3006 gst_element_state_get_name (old_state),
3007 gst_element_state_get_name (old_state),
3008 gst_element_state_get_name (pending));
3009 current = old_state;
3012 /* get our toplevel state */
3013 toplevel = BIN_IS_TOPLEVEL (bin);
3015 /* see if we reached the final state. If we are not toplevel, we also have to
3016 * stop here, the parent will continue our state. */
3017 if ((pending == current) || !toplevel) {
3018 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3019 "completed state change, pending VOID");
3021 /* mark VOID pending */
3022 pending = GST_STATE_VOID_PENDING;
3023 GST_STATE_PENDING (bin) = pending;
3024 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
3026 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3027 "continue state change, pending %s",
3028 gst_element_state_get_name (pending));
3030 cont = g_slice_new (BinContinueData);
3032 /* ref to the bin */
3033 cont->bin = gst_object_ref (bin);
3034 /* cookie to detect concurrent state change */
3035 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3036 /* pending target state */
3037 cont->pending = pending;
3039 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3040 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3043 if (old_next != GST_STATE_PLAYING) {
3044 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3045 state_changed = TRUE;
3048 GST_OBJECT_UNLOCK (bin);
3050 if (state_changed) {
3051 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3055 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3056 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3057 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3060 GST_OBJECT_LOCK (bin);
3062 /* toplevel, start continue state */
3063 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3064 bin_push_state_continue (cont);
3066 GST_DEBUG_OBJECT (bin, "state change complete");
3067 GST_STATE_BROADCAST (bin);
3073 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3078 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3079 /* if we were busy with a state change and we are requested to flag a
3080 * pending async done, we do so here */
3082 bin->priv->pending_async_done = TRUE;
3087 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3093 bin_do_eos (GstBin * bin)
3098 GST_OBJECT_LOCK (bin);
3099 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3100 * we forward the EOS message to the parent bin or application
3102 eos = GST_STATE (bin) == GST_STATE_PLAYING
3103 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3104 && is_eos (bin, &seqnum);
3105 GST_OBJECT_UNLOCK (bin);
3108 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3110 GstMessage *tmessage;
3112 /* Clear out any further messages, and reset posted_eos so we can
3113 detect any new EOS that happens (eg, after a seek). Since all
3114 sinks have now posted an EOS, there will be no further EOS events
3115 seen unless there is a new logical EOS */
3116 GST_OBJECT_LOCK (bin);
3117 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3118 bin->priv->posted_eos = FALSE;
3119 GST_OBJECT_UNLOCK (bin);
3121 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3122 gst_message_set_seqnum (tmessage, seqnum);
3123 GST_DEBUG_OBJECT (bin,
3124 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3125 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3129 /* must be called with the object lock. This function releases the lock to post
3132 bin_do_message_forward (GstBin * bin, GstMessage * message)
3134 if (bin->priv->message_forward) {
3135 GstMessage *forwarded;
3137 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3138 GST_MESSAGE_TYPE_NAME (message));
3139 GST_OBJECT_UNLOCK (bin);
3141 /* we need to convert these messages to element messages so that our parent
3142 * bin can easily ignore them and so that the application can easily
3143 * distinguish between the internally forwarded and the real messages. */
3144 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3145 gst_structure_new ("GstBinForwarded",
3146 "message", GST_TYPE_MESSAGE, message, NULL));
3148 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3150 GST_OBJECT_LOCK (bin);
3154 /* handle child messages:
3156 * This method is called synchronously when a child posts a message on
3159 * GST_MESSAGE_EOS: This message is only posted by sinks
3160 * in the PLAYING state. If all sinks posted the EOS message, post
3163 * GST_MESSAGE_STATE_DIRTY: Deprecated
3165 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3166 * element posts segment_start twice, only the last message is kept.
3168 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3169 * with the segment_done message. If there are no more segment_start
3170 * messages, post segment_done message upwards.
3172 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3173 * Whenever someone performs a duration query on the bin, we store the
3174 * result so we can answer it quicker the next time. Any element that
3175 * changes its duration marks our cached values invalid.
3176 * This message is also posted upwards. This is currently disabled
3177 * because too many elements don't post DURATION messages when the
3180 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3181 * can no longer provide a clock. The default bin behaviour is to
3182 * check if the lost clock was the one provided by the bin. If so and
3183 * we are currently in the PLAYING state, we forward the message to
3185 * This message is also generated when we remove a clock provider from
3186 * a bin. If this message is received by the application, it should
3187 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3188 * and a new base_time distribution.
3190 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3191 * can provide a clock. This mostly happens when we add a new clock
3192 * provider to the bin. The default behaviour of the bin is to mark the
3193 * currently selected clock as dirty, which will perform a clock
3194 * recalculation the next time we are asked to provide a clock.
3195 * This message is never sent to the application but is forwarded to
3198 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3199 * the state of the element and the fact that the element will need a
3200 * new base_time. This message is not forwarded to the application.
3202 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3203 * element when it posted ASYNC_START. If all elements are done, post a
3204 * ASYNC_DONE message to the parent.
3206 * OTHER: post upwards.
3209 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3212 GstMessageType type;
3213 GstMessage *tmessage;
3216 src = GST_MESSAGE_SRC (message);
3217 type = GST_MESSAGE_TYPE (message);
3219 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3220 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3221 GST_MESSAGE_TYPE_NAME (message));
3224 case GST_MESSAGE_ERROR:
3226 GST_OBJECT_LOCK (bin);
3228 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3229 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3230 GST_STATE_BROADCAST (bin);
3231 GST_OBJECT_UNLOCK (bin);
3235 case GST_MESSAGE_EOS:
3238 /* collect all eos messages from the children */
3239 GST_OBJECT_LOCK (bin);
3240 bin_do_message_forward (bin, message);
3241 /* ref message for future use */
3242 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3243 GST_OBJECT_UNLOCK (bin);
3248 case GST_MESSAGE_STATE_DIRTY:
3250 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3253 gst_message_unref (message);
3256 case GST_MESSAGE_SEGMENT_START:{
3257 gboolean post = FALSE;
3261 gst_message_parse_segment_start (message, &format, &position);
3262 seqnum = gst_message_get_seqnum (message);
3264 GST_OBJECT_LOCK (bin);
3265 bin_do_message_forward (bin, message);
3266 /* if this is the first segment-start, post to parent but not to the
3268 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3269 (GST_OBJECT_PARENT (bin) != NULL)) {
3272 /* replace any previous segment_start message from this source
3273 * with the new segment start message */
3274 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3275 GST_OBJECT_UNLOCK (bin);
3277 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3279 gst_message_set_seqnum (tmessage, seqnum);
3281 /* post segment start with initial format and position. */
3282 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3284 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3288 case GST_MESSAGE_SEGMENT_DONE:
3290 gboolean post = FALSE;
3294 gst_message_parse_segment_done (message, &format, &position);
3295 seqnum = gst_message_get_seqnum (message);
3297 GST_OBJECT_LOCK (bin);
3298 bin_do_message_forward (bin, message);
3299 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3300 /* if there are no more segment_start messages, everybody posted
3301 * a segment_done and we can post one on the bus. */
3303 /* we don't care who still has a pending segment start */
3304 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3307 /* remove all old segment_done messages */
3308 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3310 GST_OBJECT_UNLOCK (bin);
3312 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3314 gst_message_set_seqnum (tmessage, seqnum);
3316 /* post segment done with latest format and position. */
3317 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3319 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3323 case GST_MESSAGE_DURATION:
3325 /* remove all cached duration messages, next time somebody asks
3326 * for duration, we will recalculate. */
3327 GST_OBJECT_LOCK (bin);
3328 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3329 GST_OBJECT_UNLOCK (bin);
3332 case GST_MESSAGE_CLOCK_LOST:
3334 GstClock **provided_clock_p;
3335 GstElement **clock_provider_p;
3336 gboolean playing, provided, forward;
3339 gst_message_parse_clock_lost (message, &clock);
3341 GST_OBJECT_LOCK (bin);
3342 bin->clock_dirty = TRUE;
3343 /* if we lost the clock that we provided, post to parent but
3344 * only if we are PLAYING. */
3345 provided = (clock == bin->provided_clock);
3346 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3347 forward = playing & provided;
3349 GST_DEBUG_OBJECT (bin,
3350 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3351 bin->provided_clock, bin->clock_provider);
3352 provided_clock_p = &bin->provided_clock;
3353 clock_provider_p = &bin->clock_provider;
3354 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3355 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3357 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3358 provided, playing, forward);
3359 GST_OBJECT_UNLOCK (bin);
3365 gst_message_unref (message);
3368 case GST_MESSAGE_CLOCK_PROVIDE:
3372 GST_OBJECT_LOCK (bin);
3373 bin->clock_dirty = TRUE;
3374 /* a new clock is available, post to parent but not
3375 * to the application */
3376 forward = GST_OBJECT_PARENT (bin) != NULL;
3377 GST_OBJECT_UNLOCK (bin);
3383 gst_message_unref (message);
3386 case GST_MESSAGE_ASYNC_START:
3390 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3391 src ? GST_OBJECT_NAME (src) : "(NULL)");
3393 GST_OBJECT_LOCK (bin);
3394 bin_do_message_forward (bin, message);
3396 /* we ignore the message if we are going to <= READY */
3397 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3398 goto ignore_start_message;
3400 /* takes ownership of the message */
3401 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3403 bin_handle_async_start (bin);
3404 GST_OBJECT_UNLOCK (bin);
3407 ignore_start_message:
3409 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3410 gst_element_state_get_name (target));
3411 GST_OBJECT_UNLOCK (bin);
3412 gst_message_unref (message);
3416 case GST_MESSAGE_ASYNC_DONE:
3418 GstClockTime running_time;
3421 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3422 src ? GST_OBJECT_NAME (src) : "(NULL)");
3424 gst_message_parse_async_done (message, &running_time);
3426 GST_OBJECT_LOCK (bin);
3427 bin_do_message_forward (bin, message);
3429 /* ignore messages if we are shutting down */
3430 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3431 goto ignore_done_message;
3433 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3434 /* if there are no more ASYNC_START messages, everybody posted
3435 * a ASYNC_DONE and we can post one on the bus. When checking, we
3436 * don't care who still has a pending ASYNC_START */
3437 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3438 /* nothing found, remove all old ASYNC_DONE messages */
3439 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3441 GST_DEBUG_OBJECT (bin, "async elements commited");
3442 /* when we get an async done message when a state change was busy, we
3443 * need to set the pending_done flag so that at the end of the state
3444 * change we can see if we need to verify pending async elements, hence
3445 * the TRUE argument here. */
3446 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
3449 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3451 GST_OBJECT_UNLOCK (bin);
3454 ignore_done_message:
3456 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3457 gst_element_state_get_name (target));
3458 GST_OBJECT_UNLOCK (bin);
3459 gst_message_unref (message);
3463 case GST_MESSAGE_STRUCTURE_CHANGE:
3467 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3469 GST_OBJECT_LOCK (bin);
3471 /* while the pad is busy, avoid following it when doing state changes.
3472 * Don't update the cookie yet, we will do that after the structure
3473 * change finished and we are ready to inspect the new updated
3475 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3478 /* a pad link/unlink ended, signal the state change iterator that we
3479 * need to resync by updating the structure_cookie. */
3480 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3481 GST_MESSAGE_STRUCTURE_CHANGE);
3482 bin->priv->structure_cookie++;
3484 GST_OBJECT_UNLOCK (bin);
3487 gst_message_unref (message);
3498 /* Send all other messages upward */
3499 GST_DEBUG_OBJECT (bin, "posting message upward");
3500 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3505 /* generic struct passed to all query fold methods */
3514 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3515 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3517 /* for duration/position we collect all durations/positions and take
3518 * the MAX of all valid results */
3520 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3528 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3530 GstElement *item = g_value_get_object (vitem);
3532 if (gst_element_query (item, fold->query)) {
3535 g_value_set_boolean (ret, TRUE);
3537 gst_query_parse_duration (fold->query, NULL, &duration);
3539 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3541 if (duration > fold->max)
3542 fold->max = duration;
3549 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3553 gst_query_parse_duration (fold->query, &format, NULL);
3554 /* store max in query result */
3555 gst_query_set_duration (fold->query, format, fold->max);
3557 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3560 GST_OBJECT_LOCK (bin);
3561 bin->messages = g_list_prepend (bin->messages,
3562 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3563 GST_OBJECT_UNLOCK (bin);
3567 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3569 GstElement *item = g_value_get_object (vitem);
3571 if (gst_element_query (item, fold->query)) {
3574 g_value_set_boolean (ret, TRUE);
3576 gst_query_parse_position (fold->query, NULL, &position);
3578 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3580 if (position > fold->max)
3581 fold->max = position;
3588 bin_query_position_done (GstBin * bin, QueryFold * fold)
3592 gst_query_parse_position (fold->query, &format, NULL);
3593 /* store max in query result */
3594 gst_query_set_position (fold->query, format, fold->max);
3596 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3600 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3602 GstElement *item = g_value_get_object (vitem);
3604 if (gst_element_query (item, fold->query)) {
3605 GstClockTime min, max;
3608 gst_query_parse_latency (fold->query, &live, &min, &max);
3610 GST_DEBUG_OBJECT (item,
3611 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3612 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3614 /* for the combined latency we collect the MAX of all min latencies and
3615 * the MIN of all max latencies */
3617 if (min > fold->min)
3619 if (fold->max == -1)
3621 else if (max < fold->max)
3623 if (fold->live == FALSE)
3627 g_value_set_boolean (ret, FALSE);
3628 GST_DEBUG_OBJECT (item, "failed query");
3635 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3637 /* store max in query result */
3638 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3640 GST_DEBUG_OBJECT (bin,
3641 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3642 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3646 /* generic fold, return first valid result */
3648 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3650 GstElement *item = g_value_get_object (vitem);
3653 if ((res = gst_element_query (item, fold->query))) {
3654 g_value_set_boolean (ret, TRUE);
3655 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3658 /* and stop as soon as we have a valid result */
3663 gst_bin_query (GstElement * element, GstQuery * query)
3665 GstBin *bin = GST_BIN_CAST (element);
3667 gboolean res = FALSE;
3668 GstIteratorFoldFunction fold_func;
3669 QueryInitFunction fold_init = NULL;
3670 QueryDoneFunction fold_done = NULL;
3671 QueryFold fold_data;
3674 switch (GST_QUERY_TYPE (query)) {
3675 case GST_QUERY_DURATION:
3680 gst_query_parse_duration (query, &qformat, NULL);
3682 /* find cached duration query */
3683 GST_OBJECT_LOCK (bin);
3684 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3685 GstMessage *message = (GstMessage *) cached->data;
3687 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3688 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3692 gst_message_parse_duration (message, &format, &duration);
3694 /* if cached same format, copy duration in query result */
3695 if (format == qformat) {
3696 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3698 GST_OBJECT_UNLOCK (bin);
3700 gst_query_set_duration (query, qformat, duration);
3706 GST_OBJECT_UNLOCK (bin);
3707 /* no cached value found, iterate and collect durations */
3708 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3709 fold_init = bin_query_min_max_init;
3710 fold_done = bin_query_duration_done;
3713 case GST_QUERY_POSITION:
3715 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3716 fold_init = bin_query_min_max_init;
3717 fold_done = bin_query_position_done;
3720 case GST_QUERY_LATENCY:
3722 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3723 fold_init = bin_query_min_max_init;
3724 fold_done = bin_query_latency_done;
3729 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3733 fold_data.query = query;
3735 /* set the result of the query to FALSE initially */
3736 g_value_init (&ret, G_TYPE_BOOLEAN);
3737 g_value_set_boolean (&ret, res);
3739 iter = gst_bin_iterate_sinks (bin);
3740 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3741 query, GST_QUERY_TYPE_NAME (query));
3744 fold_init (bin, &fold_data);
3747 GstIteratorResult ires;
3749 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3752 case GST_ITERATOR_RESYNC:
3753 gst_iterator_resync (iter);
3755 fold_init (bin, &fold_data);
3756 g_value_set_boolean (&ret, res);
3758 case GST_ITERATOR_OK:
3759 case GST_ITERATOR_DONE:
3760 res = g_value_get_boolean (&ret);
3761 if (fold_done != NULL && res)
3762 fold_done (bin, &fold_data);
3770 gst_iterator_free (iter);
3773 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3779 compare_name (const GValue * velement, const gchar * name)
3782 GstElement *element = g_value_get_object (velement);
3784 GST_OBJECT_LOCK (element);
3785 eq = strcmp (GST_ELEMENT_NAME (element), name);
3786 GST_OBJECT_UNLOCK (element);
3792 * gst_bin_get_by_name:
3794 * @name: the element name to search for
3796 * Gets the element with the given name from a bin. This
3797 * function recurses into child bins.
3799 * Returns NULL if no element with the given name is found in the bin.
3801 * MT safe. Caller owns returned reference.
3803 * Returns: (transfer full): the #GstElement with the given name, or NULL
3806 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3808 GstIterator *children;
3809 GValue result = { 0, };
3810 GstElement *element;
3813 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3815 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3816 GST_ELEMENT_NAME (bin), name);
3818 children = gst_bin_iterate_recurse (bin);
3819 found = gst_iterator_find_custom (children,
3820 (GCompareFunc) compare_name, &result, (gpointer) name);
3821 gst_iterator_free (children);
3824 element = g_value_dup_object (&result);
3825 g_value_unset (&result);
3834 * gst_bin_get_by_name_recurse_up:
3836 * @name: the element name to search for
3838 * Gets the element with the given name from this bin. If the
3839 * element is not found, a recursion is performed on the parent bin.
3842 * - no element with the given name is found in the bin
3844 * MT safe. Caller owns returned reference.
3846 * Returns: (transfer full): the #GstElement with the given name, or NULL
3849 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3853 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3854 g_return_val_if_fail (name != NULL, NULL);
3856 result = gst_bin_get_by_name (bin, name);
3861 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3863 if (GST_IS_BIN (parent)) {
3864 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3866 gst_object_unref (parent);
3874 compare_interface (const GValue * velement, GValue * interface)
3876 GstElement *element = g_value_get_object (velement);
3877 GType interface_type = (GType) g_value_get_pointer (interface);
3880 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3889 * gst_bin_get_by_interface:
3891 * @iface: the #GType of an interface
3893 * Looks for an element inside the bin that implements the given
3894 * interface. If such an element is found, it returns the element.
3895 * You can cast this element to the given interface afterwards. If you want
3896 * all elements that implement the interface, use
3897 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3899 * MT safe. Caller owns returned reference.
3901 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3904 gst_bin_get_by_interface (GstBin * bin, GType iface)
3906 GstIterator *children;
3907 GValue result = { 0, };
3908 GstElement *element;
3910 GValue viface = { 0, };
3912 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3913 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3915 g_value_init (&viface, G_TYPE_POINTER);
3916 g_value_set_pointer (&viface, (gpointer) iface);
3918 children = gst_bin_iterate_recurse (bin);
3919 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3921 gst_iterator_free (children);
3924 element = g_value_dup_object (&result);
3925 g_value_unset (&result);
3929 g_value_unset (&viface);
3935 * gst_bin_iterate_all_by_interface:
3937 * @iface: the #GType of an interface
3939 * Looks for all elements inside the bin that implements the given
3940 * interface. You can safely cast all returned elements to the given interface.
3941 * The function recurses inside child bins. The iterator will yield a series
3942 * of #GstElement that should be unreffed after use.
3944 * Each element yielded by the iterator will have its refcount increased, so
3947 * MT safe. Caller owns returned value.
3949 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3950 * in the bin implementing the given interface, or NULL
3953 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3955 GstIterator *children;
3956 GstIterator *result;
3957 GValue viface = { 0, };
3959 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3960 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3962 g_value_init (&viface, G_TYPE_POINTER);
3963 g_value_set_pointer (&viface, (gpointer) iface);
3965 children = gst_bin_iterate_recurse (bin);
3966 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3969 g_value_unset (&viface);