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);
505 bin->priv = GST_BIN_GET_PRIVATE (bin);
506 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
507 bin->priv->structure_cookie = 0;
508 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
512 gst_bin_dispose (GObject * object)
514 GstBin *bin = GST_BIN_CAST (object);
515 GstBus **child_bus_p = &bin->child_bus;
516 GstClock **provided_clock_p = &bin->provided_clock;
517 GstElement **clock_provider_p = &bin->clock_provider;
519 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
521 GST_OBJECT_LOCK (object);
522 gst_object_replace ((GstObject **) child_bus_p, NULL);
523 gst_object_replace ((GstObject **) provided_clock_p, NULL);
524 gst_object_replace ((GstObject **) clock_provider_p, NULL);
525 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
526 GST_OBJECT_UNLOCK (object);
528 while (bin->children) {
529 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
531 if (G_UNLIKELY (bin->children != NULL)) {
532 g_critical ("could not remove elements from bin '%s'",
533 GST_STR_NULL (GST_OBJECT_NAME (object)));
536 G_OBJECT_CLASS (parent_class)->dispose (object);
541 * @name: the name of the new bin
543 * Creates a new bin with the given name.
545 * Returns: (transfer floating): a new #GstBin
548 gst_bin_new (const gchar * name)
550 return gst_element_factory_make ("bin", name);
554 gst_bin_set_property (GObject * object, guint prop_id,
555 const GValue * value, GParamSpec * pspec)
559 gstbin = GST_BIN_CAST (object);
562 case PROP_ASYNC_HANDLING:
563 GST_OBJECT_LOCK (gstbin);
564 gstbin->priv->asynchandling = g_value_get_boolean (value);
565 GST_OBJECT_UNLOCK (gstbin);
567 case PROP_MESSAGE_FORWARD:
568 GST_OBJECT_LOCK (gstbin);
569 gstbin->priv->message_forward = g_value_get_boolean (value);
570 GST_OBJECT_UNLOCK (gstbin);
573 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
579 gst_bin_get_property (GObject * object, guint prop_id,
580 GValue * value, GParamSpec * pspec)
584 gstbin = GST_BIN_CAST (object);
587 case PROP_ASYNC_HANDLING:
588 GST_OBJECT_LOCK (gstbin);
589 g_value_set_boolean (value, gstbin->priv->asynchandling);
590 GST_OBJECT_UNLOCK (gstbin);
592 case PROP_MESSAGE_FORWARD:
593 GST_OBJECT_LOCK (gstbin);
594 g_value_set_boolean (value, gstbin->priv->message_forward);
595 GST_OBJECT_UNLOCK (gstbin);
598 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
604 /* return the cached index */
606 gst_bin_get_index_func (GstElement * element)
611 bin = GST_BIN_CAST (element);
613 GST_OBJECT_LOCK (bin);
614 if ((result = bin->priv->index))
615 gst_object_ref (result);
616 GST_OBJECT_UNLOCK (bin);
621 /* set the index on all elements in this bin
626 gst_bin_set_index_func (GstElement * element, GstIndex * index)
632 GValue data = { 0, };
634 bin = GST_BIN_CAST (element);
636 GST_OBJECT_LOCK (bin);
637 old = bin->priv->index;
638 if (G_UNLIKELY (old == index))
641 gst_object_ref (index);
642 bin->priv->index = index;
643 GST_OBJECT_UNLOCK (bin);
646 gst_object_unref (old);
648 it = gst_bin_iterate_elements (bin);
650 /* set the index on all elements in the bin */
653 switch (gst_iterator_next (it, &data)) {
654 case GST_ITERATOR_OK:
656 GstElement *child = g_value_get_object (&data);
658 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
659 GST_ELEMENT_NAME (child));
660 gst_element_set_index (child, index);
662 g_value_reset (&data);
665 case GST_ITERATOR_RESYNC:
666 GST_DEBUG_OBJECT (bin, "iterator doing resync");
667 gst_iterator_resync (it);
670 case GST_ITERATOR_DONE:
671 GST_DEBUG_OBJECT (bin, "iterator done");
676 g_value_unset (&data);
677 gst_iterator_free (it);
682 GST_DEBUG_OBJECT (bin, "index was already set");
683 GST_OBJECT_UNLOCK (bin);
689 /* set the clock on all elements in this bin
694 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
700 GValue data = { 0, };
702 bin = GST_BIN_CAST (element);
704 it = gst_bin_iterate_elements (bin);
708 switch (gst_iterator_next (it, &data)) {
709 case GST_ITERATOR_OK:
711 GstElement *child = g_value_get_object (&data);
713 res &= gst_element_set_clock (child, clock);
715 g_value_reset (&data);
718 case GST_ITERATOR_RESYNC:
719 GST_DEBUG_OBJECT (bin, "iterator doing resync");
720 gst_iterator_resync (it);
724 case GST_ITERATOR_DONE:
725 GST_DEBUG_OBJECT (bin, "iterator done");
730 g_value_unset (&data);
731 gst_iterator_free (it);
734 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
739 /* get the clock for this bin by asking all of the children in this bin
741 * The ref of the returned clock in increased so unref after usage.
743 * We loop the elements in state order and pick the last clock we can
744 * get. This makes sure we get a clock from the source.
749 gst_bin_provide_clock_func (GstElement * element)
751 GstClock *result = NULL;
752 GstElement *provider = NULL;
757 GstClock **provided_clock_p;
758 GstElement **clock_provider_p;
760 bin = GST_BIN_CAST (element);
762 GST_OBJECT_LOCK (bin);
763 if (!bin->clock_dirty)
766 GST_DEBUG_OBJECT (bin, "finding new clock");
768 it = gst_bin_sort_iterator_new (bin);
769 GST_OBJECT_UNLOCK (bin);
773 switch (gst_iterator_next (it, &val)) {
774 case GST_ITERATOR_OK:
776 GstElement *child = g_value_get_object (&val);
779 clock = gst_element_provide_clock (child);
781 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
782 clock, GST_ELEMENT_NAME (child));
784 gst_object_unref (result);
785 gst_object_unref (provider);
788 provider = gst_object_ref (child);
791 g_value_reset (&val);
794 case GST_ITERATOR_RESYNC:
795 gst_iterator_resync (it);
798 case GST_ITERATOR_DONE:
803 g_value_unset (&val);
804 gst_iterator_free (it);
806 GST_OBJECT_LOCK (bin);
807 if (!bin->clock_dirty) {
809 gst_object_unref (provider);
811 gst_object_unref (result);
817 provided_clock_p = &bin->provided_clock;
818 clock_provider_p = &bin->clock_provider;
819 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
820 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
821 bin->clock_dirty = FALSE;
822 GST_DEBUG_OBJECT (bin,
823 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
825 /* Provider is not being returned to caller, just the result */
827 gst_object_unref (provider);
828 GST_OBJECT_UNLOCK (bin);
834 if ((result = bin->provided_clock))
835 gst_object_ref (result);
836 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
837 GST_OBJECT_UNLOCK (bin);
844 * functions for manipulating cached messages
849 GstMessageType types;
852 /* check if a message is of given src and type */
854 message_check (GstMessage * message, MessageFind * target)
859 eq &= GST_MESSAGE_SRC (message) == target->src;
861 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
862 GST_LOG ("looking at message %p: %d", message, eq);
868 find_message (GstBin * bin, GstObject * src, GstMessageType types)
876 result = g_list_find_custom (bin->messages, &find,
877 (GCompareFunc) message_check);
880 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
881 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
884 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
885 #ifndef GST_DISABLE_GST_DEBUG
889 for (i = 0; i < 32; i++)
890 if (types & (1 << i))
891 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
899 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
902 * A message that is cached and has the same SRC and type is replaced
903 * by the given message.
906 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
912 if ((src = GST_MESSAGE_SRC (message))) {
913 /* first find the previous message posted by this element */
914 if ((previous = find_message (bin, src, types))) {
915 GstMessage *previous_msg;
917 /* if we found a previous message, replace it */
918 previous_msg = previous->data;
919 previous->data = message;
921 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
922 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
923 GST_MESSAGE_TYPE_NAME (message));
925 gst_message_unref (previous_msg);
927 /* keep new message */
928 bin->messages = g_list_prepend (bin->messages, message);
930 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
931 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
934 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
935 GST_MESSAGE_TYPE_NAME (message));
937 gst_message_unref (message);
942 /* with LOCK. Remove all messages of given types */
944 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
952 for (walk = bin->messages; walk; walk = next) {
953 GstMessage *message = (GstMessage *) walk->data;
955 next = g_list_next (walk);
957 if (message_check (message, &find) == 0) {
958 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
959 "deleting message %p of types 0x%08x", message, types);
960 bin->messages = g_list_delete_link (bin->messages, walk);
961 gst_message_unref (message);
963 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
964 "not deleting message %p of type 0x%08x", message,
965 GST_MESSAGE_TYPE (message));
971 /* Check if the bin is EOS. We do this by scanning all sinks and
972 * checking if they posted an EOS message.
974 * call with bin LOCK */
976 is_eos (GstBin * bin, guint32 * seqnum)
983 for (walk = bin->children; walk; walk = g_list_next (walk)) {
986 element = GST_ELEMENT_CAST (walk->data);
987 if (bin_element_is_sink (element, bin) == 0) {
988 /* check if element posted EOS */
990 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
991 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
992 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
995 GST_DEBUG ("sink '%s' did not post EOS yet",
996 GST_ELEMENT_NAME (element));
1002 /* FIXME: Some tests (e.g. elements/capsfilter) use
1003 * pipelines with a dangling sinkpad but no sink element.
1004 * These tests assume that no EOS message is ever
1005 * posted on the bus so let's keep that behaviour.
1006 * In valid pipelines this doesn't make a difference.
1008 return result && n_eos > 0;
1012 unlink_pads (const GValue * item, gpointer user_data)
1017 pad = g_value_get_object (item);
1019 if ((peer = gst_pad_get_peer (pad))) {
1020 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1021 gst_pad_unlink (pad, peer);
1023 gst_pad_unlink (peer, pad);
1024 gst_object_unref (peer);
1028 /* vmethod that adds an element to a bin
1033 gst_bin_add_func (GstBin * bin, GstElement * element)
1037 gboolean is_sink, is_source, provides_clock, requires_clock;
1038 GstMessage *clock_message = NULL, *async_message = NULL;
1039 GstStateChangeReturn ret;
1041 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1043 /* we obviously can't add ourself to ourself */
1044 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1047 /* get the element name to make sure it is unique in this bin. */
1048 GST_OBJECT_LOCK (element);
1049 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1050 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1051 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1053 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1055 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1056 GST_OBJECT_UNLOCK (element);
1058 GST_OBJECT_LOCK (bin);
1060 /* then check to see if the element's name is already taken in the bin,
1061 * we can safely take the lock here. This check is probably bogus because
1062 * you can safely change the element name after this check and before setting
1063 * the object parent. The window is very small though... */
1064 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1065 goto duplicate_name;
1067 /* set the element's parent and add the element to the bin's list of children */
1068 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1069 GST_OBJECT_CAST (bin))))
1072 /* if we add a sink we become a sink */
1074 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1076 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1079 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1081 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1083 if (provides_clock) {
1084 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1086 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1087 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1089 if (requires_clock) {
1090 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1091 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1094 bin->children = g_list_prepend (bin->children, element);
1096 bin->children_cookie++;
1097 bin->priv->structure_cookie++;
1099 /* distribute the bus */
1100 gst_element_set_bus (element, bin->child_bus);
1102 /* propagate the current base_time, start_time and clock */
1103 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1104 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1105 /* it's possible that the element did not accept the clock but
1106 * that is not important right now. When the pipeline goes to PLAYING,
1107 * a new clock will be selected */
1108 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1111 /* set the cached index on the children */
1112 if (bin->priv->index)
1113 gst_element_set_index (element, bin->priv->index);
1116 ret = GST_STATE_RETURN (bin);
1117 /* no need to update the state if we are in error */
1118 if (ret == GST_STATE_CHANGE_FAILURE)
1119 goto no_state_recalc;
1121 /* update the bin state, the new element could have been an ASYNC or
1122 * NO_PREROLL element */
1123 ret = GST_STATE_RETURN (element);
1124 GST_DEBUG_OBJECT (bin, "added %s element",
1125 gst_element_state_change_return_get_name (ret));
1128 case GST_STATE_CHANGE_ASYNC:
1130 /* create message to track this aync element when it posts an async-done
1132 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1135 case GST_STATE_CHANGE_NO_PREROLL:
1136 /* ignore all async elements we might have and commit our state */
1137 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1139 case GST_STATE_CHANGE_FAILURE:
1146 GST_OBJECT_UNLOCK (bin);
1148 /* post the messages on the bus of the element so that the bin can handle
1151 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1154 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1156 /* unlink all linked pads */
1157 it = gst_element_iterate_pads (element);
1158 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1159 gst_iterator_free (it);
1161 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1164 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1165 gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
1172 /* ERROR handling here */
1175 GST_OBJECT_LOCK (bin);
1176 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1177 GST_OBJECT_UNLOCK (bin);
1182 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1183 elem_name, GST_ELEMENT_NAME (bin));
1184 GST_OBJECT_UNLOCK (bin);
1190 g_warning ("Element '%s' already has parent", elem_name);
1191 GST_OBJECT_UNLOCK (bin);
1200 * @element: (transfer full): the #GstElement to add
1202 * Adds the given element to the bin. Sets the element's parent, and thus
1203 * takes ownership of the element. An element can only be added to one bin.
1205 * If the element's pads are linked to other pads, the pads will be unlinked
1206 * before the element is added to the bin.
1209 * When you add an element to an already-running pipeline, you will have to
1210 * take care to set the state of the newly-added element to the desired
1211 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1212 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1213 * The bin or pipeline will not take care of this for you.
1218 * Returns: TRUE if the element could be added, FALSE if
1219 * the bin does not want to accept the element.
1222 gst_bin_add (GstBin * bin, GstElement * element)
1224 GstBinClass *bclass;
1227 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1228 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1230 bclass = GST_BIN_GET_CLASS (bin);
1232 if (G_UNLIKELY (bclass->add_element == NULL))
1235 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1236 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1237 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1239 result = bclass->add_element (bin, element);
1243 /* ERROR handling */
1246 g_warning ("adding elements to bin '%s' is not supported",
1247 GST_ELEMENT_NAME (bin));
1252 /* remove an element from the bin
1257 gst_bin_remove_func (GstBin * bin, GstElement * element)
1261 gboolean is_sink, is_source, provides_clock, requires_clock;
1262 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1263 GstMessage *clock_message = NULL;
1264 GstClock **provided_clock_p;
1265 GstElement **clock_provider_p;
1267 gboolean other_async, this_async, have_no_preroll;
1268 GstStateChangeReturn ret;
1270 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1272 GST_OBJECT_LOCK (bin);
1274 GST_OBJECT_LOCK (element);
1275 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1277 if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
1280 /* remove the parent ref */
1281 GST_OBJECT_PARENT (element) = NULL;
1283 /* grab element name so we can print it */
1284 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1285 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1287 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1289 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1290 GST_OBJECT_UNLOCK (element);
1294 othersource = FALSE;
1295 otherprovider = FALSE;
1296 otherrequirer = FALSE;
1297 have_no_preroll = FALSE;
1298 /* iterate the elements, we collect which ones are async and no_preroll. We
1299 * also remove the element when we find it. */
1300 for (walk = bin->children; walk; walk = next) {
1301 GstElement *child = GST_ELEMENT_CAST (walk->data);
1303 next = g_list_next (walk);
1305 if (child == element) {
1307 /* remove the element */
1308 bin->children = g_list_delete_link (bin->children, walk);
1310 gboolean child_sink, child_source, child_provider, child_requirer;
1312 GST_OBJECT_LOCK (child);
1313 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1314 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1316 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1318 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1319 /* when we remove a sink, check if there are other sinks. */
1320 if (is_sink && !othersink && child_sink)
1322 if (is_source && !othersource && child_source)
1324 if (provides_clock && !otherprovider && child_provider)
1325 otherprovider = TRUE;
1326 if (requires_clock && !otherrequirer && child_requirer)
1327 otherrequirer = TRUE;
1328 /* check if we have NO_PREROLL children */
1329 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1330 have_no_preroll = TRUE;
1331 GST_OBJECT_UNLOCK (child);
1335 /* the element must have been in the bin's list of children */
1336 if (G_UNLIKELY (!found))
1339 /* we now removed the element from the list of elements, increment the cookie
1340 * so that others can detect a change in the children list. */
1342 bin->children_cookie++;
1343 bin->priv->structure_cookie++;
1345 if (is_sink && !othersink) {
1346 /* we're not a sink anymore */
1347 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1348 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1350 if (is_source && !othersource) {
1351 /* we're not a source anymore */
1352 GST_DEBUG_OBJECT (bin, "we removed the last source");
1353 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1355 if (provides_clock && !otherprovider) {
1356 /* we're not a clock provider anymore */
1357 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1358 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1360 if (requires_clock && !otherrequirer) {
1361 /* we're not a clock requirer anymore */
1362 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1363 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1366 /* if the clock provider for this element is removed, we lost
1367 * the clock as well, we need to inform the parent of this
1368 * so that it can select a new clock */
1369 if (bin->clock_provider == element) {
1370 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1371 bin->clock_dirty = TRUE;
1373 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1374 provided_clock_p = &bin->provided_clock;
1375 clock_provider_p = &bin->clock_provider;
1376 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1377 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1380 /* remove messages for the element, if there was a pending ASYNC_START
1381 * message we must see if removing the element caused the bin to lose its
1384 other_async = FALSE;
1385 for (walk = bin->messages; walk; walk = next) {
1386 GstMessage *message = (GstMessage *) walk->data;
1387 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1390 next = g_list_next (walk);
1393 switch (GST_MESSAGE_TYPE (message)) {
1394 case GST_MESSAGE_ASYNC_START:
1400 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1402 case GST_MESSAGE_STRUCTURE_CHANGE:
1406 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1408 /* it's unlikely that this message is still in the list of messages
1409 * because this would mean that a link/unlink is busy in another thread
1410 * while we remove the element. We still have to remove the message
1411 * because we might not receive the done message anymore when the element
1412 * is removed from the bin. */
1413 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1414 if (owner == element)
1425 /* delete all message types */
1426 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1427 message, elem_name);
1428 bin->messages = g_list_delete_link (bin->messages, walk);
1429 gst_message_unref (message);
1433 /* get last return */
1434 ret = GST_STATE_RETURN (bin);
1436 /* no need to update the state if we are in error */
1437 if (ret == GST_STATE_CHANGE_FAILURE)
1438 goto no_state_recalc;
1440 if (!other_async && this_async) {
1441 /* all other elements were not async and we removed the async one,
1442 * handle the async-done case because we are not async anymore now. */
1443 GST_DEBUG_OBJECT (bin,
1444 "we removed the last async element, have no_preroll %d",
1447 /* the current state return of the bin depends on if there are no_preroll
1448 * elements in the pipeline or not */
1449 if (have_no_preroll)
1450 ret = GST_STATE_CHANGE_NO_PREROLL;
1452 ret = GST_STATE_CHANGE_SUCCESS;
1454 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1456 GST_DEBUG_OBJECT (bin,
1457 "recalc state preroll: %d, other async: %d, this async %d",
1458 have_no_preroll, other_async, this_async);
1460 if (have_no_preroll) {
1461 ret = GST_STATE_CHANGE_NO_PREROLL;
1462 } else if (other_async) {
1463 /* there are other async elements and we were not doing an async state
1464 * change, change our pending state and go async */
1465 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1466 GST_STATE_NEXT (bin) = GST_STATE (bin);
1467 GST_STATE_PENDING (bin) = GST_STATE (bin);
1469 ret = GST_STATE_CHANGE_ASYNC;
1471 GST_STATE_RETURN (bin) = ret;
1475 gst_element_set_bus (element, NULL);
1476 /* Clear the clock we provided to the element */
1477 gst_element_set_clock (element, NULL);
1478 GST_OBJECT_UNLOCK (bin);
1481 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1483 /* unlink all linked pads */
1484 it = gst_element_iterate_pads (element);
1485 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1486 gst_iterator_free (it);
1488 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1491 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1492 gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
1496 /* element is really out of our control now */
1497 gst_object_unref (element);
1501 /* ERROR handling */
1504 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1505 GST_ELEMENT_NAME (bin));
1506 GST_OBJECT_UNLOCK (element);
1507 GST_OBJECT_UNLOCK (bin);
1516 * @element: (transfer none): the #GstElement to remove
1518 * Removes the element from the bin, unparenting it as well.
1519 * Unparenting the element means that the element will be dereferenced,
1520 * so if the bin holds the only reference to the element, the element
1521 * will be freed in the process of removing it from the bin. If you
1522 * want the element to still exist after removing, you need to call
1523 * gst_object_ref() before removing it from the bin.
1525 * If the element's pads are linked to other pads, the pads will be unlinked
1526 * before the element is removed from the bin.
1530 * Returns: TRUE if the element could be removed, FALSE if
1531 * the bin does not want to remove the element.
1534 gst_bin_remove (GstBin * bin, GstElement * element)
1536 GstBinClass *bclass;
1539 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1540 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1542 bclass = GST_BIN_GET_CLASS (bin);
1544 if (G_UNLIKELY (bclass->remove_element == NULL))
1547 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1548 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1550 result = bclass->remove_element (bin, element);
1554 /* ERROR handling */
1557 g_warning ("removing elements from bin '%s' is not supported",
1558 GST_ELEMENT_NAME (bin));
1564 * gst_bin_iterate_elements:
1567 * Gets an iterator for the elements in this bin.
1569 * Each element yielded by the iterator will have its refcount increased, so
1572 * MT safe. Caller owns returned value.
1574 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1577 gst_bin_iterate_elements (GstBin * bin)
1579 GstIterator *result;
1581 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1583 GST_OBJECT_LOCK (bin);
1584 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1585 GST_OBJECT_GET_LOCK (bin),
1586 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1587 GST_OBJECT_UNLOCK (bin);
1592 static GstIteratorItem
1593 iterate_child_recurse (GstIterator * it, const GValue * item)
1595 GstElement *child = g_value_get_object (item);
1597 if (GST_IS_BIN (child)) {
1598 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1600 gst_iterator_push (it, other);
1602 return GST_ITERATOR_ITEM_PASS;
1606 * gst_bin_iterate_recurse:
1609 * Gets an iterator for the elements in this bin.
1610 * This iterator recurses into GstBin children.
1612 * Each element yielded by the iterator will have its refcount increased, so
1615 * MT safe. Caller owns returned value.
1617 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1620 gst_bin_iterate_recurse (GstBin * bin)
1622 GstIterator *result;
1624 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1626 GST_OBJECT_LOCK (bin);
1627 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1628 GST_OBJECT_GET_LOCK (bin),
1629 &bin->children_cookie,
1631 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1632 GST_OBJECT_UNLOCK (bin);
1637 /* returns 0 when TRUE because this is a GCompareFunc */
1640 bin_element_is_sink (GstElement * child, GstBin * bin)
1644 /* we lock the child here for the remainder of the function to
1645 * get its name and flag safely. */
1646 GST_OBJECT_LOCK (child);
1647 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1649 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1650 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1652 GST_OBJECT_UNLOCK (child);
1653 return is_sink ? 0 : 1;
1657 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1659 GstBin *bin = g_value_get_object (vbin);
1660 GstElement *child = g_value_get_object (vchild);
1662 return (bin_element_is_sink (child, bin));
1666 * gst_bin_iterate_sinks:
1669 * Gets an iterator for all elements in the bin that have the
1670 * #GST_ELEMENT_FLAG_SINK flag set.
1672 * Each element yielded by the iterator will have its refcount increased, so
1675 * MT safe. Caller owns returned value.
1677 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1680 gst_bin_iterate_sinks (GstBin * bin)
1682 GstIterator *children;
1683 GstIterator *result;
1684 GValue vbin = { 0, };
1686 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1688 g_value_init (&vbin, GST_TYPE_BIN);
1689 g_value_set_object (&vbin, bin);
1691 children = gst_bin_iterate_elements (bin);
1692 result = gst_iterator_filter (children,
1693 (GCompareFunc) sink_iterator_filter, &vbin);
1695 g_value_unset (&vbin);
1700 /* returns 0 when TRUE because this is a GCompareFunc */
1703 bin_element_is_src (GstElement * child, GstBin * bin)
1707 /* we lock the child here for the remainder of the function to
1708 * get its name and other info safely. */
1709 GST_OBJECT_LOCK (child);
1710 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1712 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1713 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1715 GST_OBJECT_UNLOCK (child);
1716 return is_src ? 0 : 1;
1720 src_iterator_filter (const GValue * vchild, GValue * vbin)
1722 GstBin *bin = g_value_get_object (vbin);
1723 GstElement *child = g_value_get_object (vchild);
1725 return (bin_element_is_src (child, bin));
1729 * gst_bin_iterate_sources:
1732 * Gets an iterator for all elements in the bin that have the
1733 * #GST_ELEMENT_FLAG_SOURCE flag set.
1735 * Each element yielded by the iterator will have its refcount increased, so
1738 * MT safe. Caller owns returned value.
1740 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1743 gst_bin_iterate_sources (GstBin * bin)
1745 GstIterator *children;
1746 GstIterator *result;
1747 GValue vbin = { 0, };
1749 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1751 g_value_init (&vbin, GST_TYPE_BIN);
1752 g_value_set_object (&vbin, bin);
1754 children = gst_bin_iterate_elements (bin);
1755 result = gst_iterator_filter (children,
1756 (GCompareFunc) src_iterator_filter, &vbin);
1758 g_value_unset (&vbin);
1766 static GstStateChangeReturn
1767 gst_bin_get_state_func (GstElement * element, GstState * state,
1768 GstState * pending, GstClockTime timeout)
1770 GstStateChangeReturn ret;
1772 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1775 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1781 /***********************************************
1782 * Topologically sorted iterator
1783 * see http://en.wikipedia.org/wiki/Topological_sorting
1785 * For each element in the graph, an entry is kept in a HashTable
1786 * with its number of srcpad connections (degree).
1787 * We then change state of all elements without dependencies
1788 * (degree 0) and decrement the degree of all elements connected
1789 * on the sinkpads. When an element reaches degree 0, its state is
1791 * When all elements are handled the algorithm stops.
1793 typedef struct _GstBinSortIterator
1796 GQueue queue; /* elements queued for state change */
1797 GstBin *bin; /* bin we iterate */
1798 gint mode; /* adding or removing dependency */
1799 GstElement *best; /* next element with least dependencies */
1800 gint best_deg; /* best degree */
1801 GHashTable *hash; /* hashtable with element dependencies */
1802 gboolean dirty; /* we detected structure change */
1803 } GstBinSortIterator;
1806 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1807 GstBinSortIterator * copy)
1809 GHashTableIter iter;
1810 gpointer key, value;
1812 copy->queue = it->queue;
1813 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1815 copy->bin = gst_object_ref (it->bin);
1817 copy->best = gst_object_ref (it->best);
1819 copy->hash = g_hash_table_new (NULL, NULL);
1820 g_hash_table_iter_init (&iter, it->hash);
1821 while (g_hash_table_iter_next (&iter, &key, &value))
1822 g_hash_table_insert (copy->hash, key, value);
1825 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1826 #define HASH_SET_DEGREE(bit, elem, deg) \
1827 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1828 #define HASH_GET_DEGREE(bit, elem) \
1829 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1831 /* add element to queue of next elements in the iterator.
1832 * We push at the tail to give higher priority elements a
1835 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1837 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1838 GST_ELEMENT_NAME (element));
1839 gst_object_ref (element);
1840 g_queue_push_tail (&bit->queue, element);
1841 HASH_SET_DEGREE (bit, element, -1);
1845 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1849 if ((find = g_queue_find (&bit->queue, element))) {
1850 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1851 GST_ELEMENT_NAME (element));
1853 g_queue_delete_link (&bit->queue, find);
1854 gst_object_unref (element);
1856 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1857 GST_ELEMENT_NAME (element));
1861 /* clear the queue, unref all objects as we took a ref when
1862 * we added them to the queue */
1864 clear_queue (GQueue * queue)
1868 while ((p = g_queue_pop_head (queue)))
1869 gst_object_unref (p);
1872 /* set all degrees to 0. Elements marked as a sink are
1873 * added to the queue immediately. Since we only look at the SINK flag of the
1874 * element, it is possible that we add non-sinks to the queue. These will be
1875 * removed from the queue again when we can prove that it provides data for some
1878 reset_degree (GstElement * element, GstBinSortIterator * bit)
1882 /* sinks are added right away */
1883 GST_OBJECT_LOCK (element);
1884 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1885 GST_OBJECT_UNLOCK (element);
1888 add_to_queue (bit, element);
1890 /* others are marked with 0 and handled when sinks are done */
1891 HASH_SET_DEGREE (bit, element, 0);
1895 /* adjust the degree of all elements connected to the given
1896 * element. If a degree of an element drops to 0, it is
1897 * added to the queue of elements to schedule next.
1899 * We have to make sure not to cross the bin boundary this element
1903 update_degree (GstElement * element, GstBinSortIterator * bit)
1905 gboolean linked = FALSE;
1907 GST_OBJECT_LOCK (element);
1908 /* don't touch degree if element has no sinkpads */
1909 if (element->numsinkpads != 0) {
1910 /* loop over all sinkpads, decrement degree for all connected
1911 * elements in this bin */
1914 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1917 pad = GST_PAD_CAST (pads->data);
1919 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1920 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1921 GST_MESSAGE_STRUCTURE_CHANGE))) {
1922 /* mark the iterator as dirty because we won't be updating the degree
1923 * of the peer parent now. This would result in the 'loop detected'
1924 * later on because the peer parent element could become the best next
1925 * element with a degree > 0. We will simply continue our state
1926 * changes and we'll eventually resync when the unlink completed and
1927 * the iterator cookie is updated. */
1932 if ((peer = gst_pad_get_peer (pad))) {
1933 GstElement *peer_element;
1935 if ((peer_element = gst_pad_get_parent_element (peer))) {
1936 GST_OBJECT_LOCK (peer_element);
1937 /* check that we don't go outside of this bin */
1938 if (GST_OBJECT_CAST (peer_element)->parent ==
1939 GST_OBJECT_CAST (bit->bin)) {
1940 gint old_deg, new_deg;
1942 old_deg = HASH_GET_DEGREE (bit, peer_element);
1944 /* check to see if we added an element as sink that was not really a
1945 * sink because it was connected to some other element. */
1946 if (old_deg == -1) {
1947 remove_from_queue (bit, peer_element);
1950 new_deg = old_deg + bit->mode;
1952 GST_DEBUG_OBJECT (bit->bin,
1953 "change element %s, degree %d->%d, linked to %s",
1954 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1955 GST_ELEMENT_NAME (element));
1957 /* update degree, it is possible that an element was in 0 and
1958 * reaches -1 here. This would mean that the element had no sinkpads
1959 * but became linked while the state change was happening. We will
1960 * resync on this with the structure change message. */
1962 /* degree hit 0, add to queue */
1963 add_to_queue (bit, peer_element);
1965 HASH_SET_DEGREE (bit, peer_element, new_deg);
1969 GST_OBJECT_UNLOCK (peer_element);
1970 gst_object_unref (peer_element);
1972 gst_object_unref (peer);
1977 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1978 GST_ELEMENT_NAME (element));
1980 GST_OBJECT_UNLOCK (element);
1983 /* find the next best element not handled yet. This is the one
1984 * with the lowest non-negative degree */
1986 find_element (GstElement * element, GstBinSortIterator * bit)
1990 /* element is already handled */
1991 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1994 /* first element or element with smaller degree */
1995 if (bit->best == NULL || bit->best_deg > degree) {
1996 bit->best = element;
1997 bit->best_deg = degree;
2001 /* get next element in iterator. the returned element has the
2002 * refcount increased */
2003 static GstIteratorResult
2004 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2007 GstBin *bin = bit->bin;
2009 /* empty queue, we have to find a next best element */
2010 if (g_queue_is_empty (&bit->queue)) {
2012 bit->best_deg = G_MAXINT;
2013 g_list_foreach (bin->children, (GFunc) find_element, bit);
2014 if ((best = bit->best)) {
2015 /* when we detected an unlink, don't warn because our degrees might be
2016 * screwed up. We will resync later */
2017 if (bit->best_deg != 0 && !bit->dirty) {
2018 /* we don't fail on this one yet */
2019 GST_WARNING_OBJECT (bin, "loop dected in graph");
2020 g_warning ("loop detected in the graph of bin '%s'!!",
2021 GST_ELEMENT_NAME (bin));
2023 /* best unhandled element, schedule as next element */
2024 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2025 GST_ELEMENT_NAME (best));
2026 HASH_SET_DEGREE (bit, best, -1);
2027 g_value_set_object (result, best);
2029 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2030 /* no more unhandled elements, we are done */
2031 return GST_ITERATOR_DONE;
2034 /* everything added to the queue got reffed */
2035 best = g_queue_pop_head (&bit->queue);
2036 g_value_set_object (result, best);
2037 gst_object_unref (best);
2040 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2041 /* update degrees of linked elements */
2042 update_degree (best, bit);
2044 return GST_ITERATOR_OK;
2047 /* clear queues, recalculate the degrees and restart. */
2049 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2051 GstBin *bin = bit->bin;
2053 GST_DEBUG_OBJECT (bin, "resync");
2055 clear_queue (&bit->queue);
2057 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2058 /* calc degrees, incrementing */
2060 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2061 /* for the rest of the function we decrement the degrees */
2065 /* clear queues, unref bin and free iterator. */
2067 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2069 GstBin *bin = bit->bin;
2071 GST_DEBUG_OBJECT (bin, "free");
2072 clear_queue (&bit->queue);
2073 g_hash_table_destroy (bit->hash);
2074 gst_object_unref (bin);
2077 /* should be called with the bin LOCK held */
2078 static GstIterator *
2079 gst_bin_sort_iterator_new (GstBin * bin)
2081 GstBinSortIterator *result;
2083 /* we don't need an ItemFunction because we ref the items in the _next
2085 result = (GstBinSortIterator *)
2086 gst_iterator_new (sizeof (GstBinSortIterator),
2088 GST_OBJECT_GET_LOCK (bin),
2089 &bin->priv->structure_cookie,
2090 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2091 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2092 (GstIteratorItemFunction) NULL,
2093 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2094 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2095 g_queue_init (&result->queue);
2096 result->hash = g_hash_table_new (NULL, NULL);
2097 gst_object_ref (bin);
2099 gst_bin_sort_iterator_resync (result);
2101 return (GstIterator *) result;
2105 * gst_bin_iterate_sorted:
2108 * Gets an iterator for the elements in this bin in topologically
2109 * sorted order. This means that the elements are returned from
2110 * the most downstream elements (sinks) to the sources.
2112 * This function is used internally to perform the state changes
2113 * of the bin elements and for clock selection.
2115 * Each element yielded by the iterator will have its refcount increased, so
2118 * MT safe. Caller owns returned value.
2120 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2123 gst_bin_iterate_sorted (GstBin * bin)
2125 GstIterator *result;
2127 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2129 GST_OBJECT_LOCK (bin);
2130 result = gst_bin_sort_iterator_new (bin);
2131 GST_OBJECT_UNLOCK (bin);
2136 static GstStateChangeReturn
2137 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2138 GstClockTime base_time, GstClockTime start_time, GstState current,
2141 GstStateChangeReturn ret;
2142 GstState child_current, child_pending;
2146 GST_STATE_LOCK (element);
2148 GST_OBJECT_LOCK (element);
2149 /* set base_time and start time on child */
2150 GST_ELEMENT_START_TIME (element) = start_time;
2151 element->base_time = base_time;
2152 /* peel off the locked flag */
2153 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2154 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2155 ret = GST_STATE_RETURN (element);
2156 child_current = GST_STATE (element);
2157 child_pending = GST_STATE_PENDING (element);
2158 GST_OBJECT_UNLOCK (element);
2160 /* skip locked elements */
2161 if (G_UNLIKELY (locked))
2164 /* if the element was no preroll, just start changing the state regardless
2165 * if it had async elements (in the case of a bin) because they won't preroll
2167 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2168 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2172 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2173 "current %s pending %s, desired next %s",
2174 gst_element_state_get_name (child_current),
2175 gst_element_state_get_name (child_pending),
2176 gst_element_state_get_name (next));
2178 /* always recurse into bins so that we can set the base time */
2179 if (GST_IS_BIN (element))
2182 /* Try not to change the state of elements that are already in the state we're
2184 if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
2185 /* child is already at the requested state, return previous return. Note that
2186 * if the child has a pending state to next, we will still call the
2187 * set_state function */
2189 } else if (next > current) {
2190 /* upward state change */
2191 if (child_pending == GST_STATE_VOID_PENDING) {
2192 /* .. and the child is not busy doing anything */
2193 if (child_current > next) {
2194 /* .. and is already past the requested state, assume it got there
2196 ret = GST_STATE_CHANGE_SUCCESS;
2199 } else if (child_pending > child_current) {
2200 /* .. and the child is busy going upwards */
2201 if (child_current >= next) {
2202 /* .. and is already past the requested state, assume it got there
2204 ret = GST_STATE_CHANGE_SUCCESS;
2208 /* .. and the child is busy going downwards */
2209 if (child_current > next) {
2210 /* .. and is already past the requested state, assume it got there
2212 ret = GST_STATE_CHANGE_SUCCESS;
2216 } else if (next < current) {
2217 /* downward state change */
2218 if (child_pending == GST_STATE_VOID_PENDING) {
2219 /* .. and the child is not busy doing anything */
2220 if (child_current < next) {
2221 /* .. and is already past the requested state, assume it got there
2223 ret = GST_STATE_CHANGE_SUCCESS;
2226 } else if (child_pending < child_current) {
2227 /* .. and the child is busy going downwards */
2228 if (child_current <= next) {
2229 /* .. and is already past the requested state, assume it got there
2231 ret = GST_STATE_CHANGE_SUCCESS;
2235 /* .. and the child is busy going upwards */
2236 if (child_current < next) {
2237 /* .. and is already past the requested state, assume it got there
2239 ret = GST_STATE_CHANGE_SUCCESS;
2246 GST_OBJECT_LOCK (bin);
2247 /* the element was busy with an upwards async state change, we must wait for
2248 * an ASYNC_DONE message before we attemp to change the state. */
2250 find_message (bin, GST_OBJECT_CAST (element),
2251 GST_MESSAGE_ASYNC_START))) {
2252 #ifndef GST_DISABLE_GST_DEBUG
2253 GstMessage *message = GST_MESSAGE_CAST (found->data);
2255 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2256 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2258 /* only wait for upward state changes */
2259 if (next > current) {
2260 /* We found an async element check if we can force its state to change or
2261 * if we have to wait for it to preroll. */
2265 GST_OBJECT_UNLOCK (bin);
2268 GST_DEBUG_OBJECT (bin,
2269 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2270 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2271 GST_TIME_ARGS (base_time));
2274 ret = gst_element_set_state (element, next);
2276 GST_STATE_UNLOCK (element);
2282 GST_DEBUG_OBJECT (element,
2283 "element is locked, return previous return %s",
2284 gst_element_state_change_return_get_name (ret));
2285 GST_STATE_UNLOCK (element);
2290 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2291 "skipping transition from %s to %s",
2292 gst_element_state_get_name (child_current),
2293 gst_element_state_get_name (next));
2294 GST_STATE_UNLOCK (element);
2299 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2300 GST_OBJECT_UNLOCK (bin);
2301 GST_STATE_UNLOCK (element);
2302 return GST_STATE_CHANGE_ASYNC;
2306 /* gst_iterator_fold functions for pads_activate
2307 * Stop the iterator if activating one pad failed. */
2309 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2311 GstPad *pad = g_value_get_object (vpad);
2312 gboolean cont = TRUE;
2314 if (!(cont = gst_pad_set_active (pad, *active)))
2315 g_value_set_boolean (ret, FALSE);
2320 /* returns false on error or early cutout of the fold, true if all
2321 * pads in @iter were (de)activated successfully. */
2323 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2325 GstIteratorResult ires;
2328 /* no need to unset this later, it's just a boolean */
2329 g_value_init (&ret, G_TYPE_BOOLEAN);
2330 g_value_set_boolean (&ret, TRUE);
2333 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2336 case GST_ITERATOR_RESYNC:
2337 /* need to reset the result again */
2338 g_value_set_boolean (&ret, TRUE);
2339 gst_iterator_resync (iter);
2341 case GST_ITERATOR_DONE:
2342 /* all pads iterated, return collected value */
2345 /* iterator returned _ERROR or premature end with _OK,
2346 * mark an error and exit */
2347 g_value_set_boolean (&ret, FALSE);
2352 /* return collected value */
2353 return g_value_get_boolean (&ret);
2356 /* is called with STATE_LOCK
2359 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2364 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2366 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2367 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2368 gst_iterator_free (iter);
2369 if (G_UNLIKELY (!fold_ok))
2372 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2379 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2385 * gst_bin_recalculate_latency:
2388 * Query @bin for the current latency using and reconfigures this latency to all the
2389 * elements with a LATENCY event.
2391 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2392 * is posted on the bus.
2394 * This function simply emits the 'do-latency' signal so any custom latency
2395 * calculations will be performed.
2397 * Returns: %TRUE if the latency could be queried and reconfigured.
2402 gst_bin_recalculate_latency (GstBin * bin)
2406 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2407 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2413 gst_bin_do_latency_func (GstBin * bin)
2416 GstElement *element;
2417 GstClockTime min_latency, max_latency;
2420 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2422 element = GST_ELEMENT_CAST (bin);
2424 GST_DEBUG_OBJECT (element, "querying latency");
2426 query = gst_query_new_latency ();
2427 if ((res = gst_element_query (element, query))) {
2430 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2432 GST_DEBUG_OBJECT (element,
2433 "got min latency %" GST_TIME_FORMAT ", max latency %"
2434 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2435 GST_TIME_ARGS (max_latency), live);
2437 if (max_latency < min_latency) {
2438 /* this is an impossible situation, some parts of the pipeline might not
2439 * work correctly. We post a warning for now. */
2440 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2441 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2442 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2443 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2446 /* configure latency on elements */
2447 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2449 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2450 GST_TIME_ARGS (min_latency));
2452 GST_WARNING_OBJECT (element,
2453 "did not really configure latency of %" GST_TIME_FORMAT,
2454 GST_TIME_ARGS (min_latency));
2457 /* this is not a real problem, we just don't configure any latency. */
2458 GST_WARNING_OBJECT (element, "failed to query latency");
2460 gst_query_unref (query);
2466 gst_bin_state_changed (GstElement * element, GstState oldstate,
2467 GstState newstate, GstState pending)
2469 GstElementClass *pklass = (GstElementClass *) parent_class;
2471 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2472 bin_do_eos (GST_BIN_CAST (element));
2474 if (pklass->state_changed)
2475 pklass->state_changed (element, oldstate, newstate, pending);
2478 static GstStateChangeReturn
2479 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2482 GstStateChangeReturn ret;
2483 GstState current, next;
2484 gboolean have_async;
2485 gboolean have_no_preroll;
2486 GstClockTime base_time, start_time;
2489 GValue data = { 0, };
2491 /* we don't need to take the STATE_LOCK, it is already taken */
2492 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2493 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2495 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2496 "changing state of children from %s to %s",
2497 gst_element_state_get_name (current), gst_element_state_get_name (next));
2499 bin = GST_BIN_CAST (element);
2502 case GST_STATE_PLAYING:
2506 GST_OBJECT_LOCK (bin);
2507 toplevel = BIN_IS_TOPLEVEL (bin);
2508 GST_OBJECT_UNLOCK (bin);
2511 gst_bin_recalculate_latency (bin);
2514 case GST_STATE_PAUSED:
2515 /* Clear EOS list on next PAUSED */
2516 GST_OBJECT_LOCK (bin);
2517 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2518 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2519 bin->priv->posted_eos = FALSE;
2520 GST_OBJECT_UNLOCK (bin);
2521 if (current == GST_STATE_READY)
2522 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2523 goto activate_failure;
2525 case GST_STATE_READY:
2526 /* Clear message list on next READY */
2527 GST_OBJECT_LOCK (bin);
2528 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2529 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2530 GST_OBJECT_UNLOCK (bin);
2531 if (current == GST_STATE_PAUSED)
2532 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2533 goto activate_failure;
2535 case GST_STATE_NULL:
2536 if (current == GST_STATE_READY)
2537 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2538 goto activate_failure;
2544 /* this flag is used to make the async state changes return immediately. We
2545 * don't want them to interfere with this state change */
2546 GST_OBJECT_LOCK (bin);
2547 bin->polling = TRUE;
2548 GST_OBJECT_UNLOCK (bin);
2550 /* iterate in state change order */
2551 it = gst_bin_iterate_sorted (bin);
2553 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2554 * Note how we don't reset this value when a resync happens, the reason being
2555 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2556 * even after a resync when the async element is gone */
2560 /* take base_time */
2561 base_time = gst_element_get_base_time (element);
2562 start_time = gst_element_get_start_time (element);
2564 have_no_preroll = FALSE;
2568 switch (gst_iterator_next (it, &data)) {
2569 case GST_ITERATOR_OK:
2573 child = g_value_get_object (&data);
2575 /* set state and base_time now */
2576 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2580 case GST_STATE_CHANGE_SUCCESS:
2581 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2582 "child '%s' changed state to %d(%s) successfully",
2583 GST_ELEMENT_NAME (child), next,
2584 gst_element_state_get_name (next));
2586 case GST_STATE_CHANGE_ASYNC:
2588 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2589 "child '%s' is changing state asynchronously to %s",
2590 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2594 case GST_STATE_CHANGE_FAILURE:{
2597 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2598 "child '%s' failed to go to state %d(%s)",
2599 GST_ELEMENT_NAME (child),
2600 next, gst_element_state_get_name (next));
2602 /* Only fail if the child is still inside
2603 * this bin. It might've been removed already
2604 * because of the error by the bin subclass
2605 * to ignore the error. */
2606 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2607 if (parent == GST_OBJECT_CAST (element)) {
2608 /* element is still in bin, really error now */
2609 gst_object_unref (parent);
2612 /* child removed from bin, let the resync code redo the state
2614 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2615 "child '%s' was removed from the bin",
2616 GST_ELEMENT_NAME (child));
2619 gst_object_unref (parent);
2623 case GST_STATE_CHANGE_NO_PREROLL:
2624 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2625 "child '%s' changed state to %d(%s) successfully without preroll",
2626 GST_ELEMENT_NAME (child), next,
2627 gst_element_state_get_name (next));
2628 have_no_preroll = TRUE;
2631 g_assert_not_reached ();
2634 g_value_reset (&data);
2637 case GST_ITERATOR_RESYNC:
2638 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2639 gst_iterator_resync (it);
2642 case GST_ITERATOR_DONE:
2643 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2649 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2650 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2653 if (have_no_preroll) {
2654 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2655 "we have NO_PREROLL elements %s -> NO_PREROLL",
2656 gst_element_state_change_return_get_name (ret));
2657 ret = GST_STATE_CHANGE_NO_PREROLL;
2658 } else if (have_async) {
2659 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2660 "we have ASYNC elements %s -> ASYNC",
2661 gst_element_state_change_return_get_name (ret));
2662 ret = GST_STATE_CHANGE_ASYNC;
2666 g_value_unset (&data);
2667 gst_iterator_free (it);
2669 GST_OBJECT_LOCK (bin);
2670 bin->polling = FALSE;
2671 /* it's possible that we did not get ASYNC from the children while the bin is
2672 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2673 * itself as the source. In that case we still want to check if the state
2674 * change completed. */
2675 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2676 /* no element returned ASYNC and there are no pending async_done messages,
2677 * we can just complete. */
2678 GST_DEBUG_OBJECT (bin, "no async elements");
2681 /* when we get here an ASYNC element was found */
2682 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2683 /* we ignore ASYNC state changes when we go to READY or NULL */
2684 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2685 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2689 GST_DEBUG_OBJECT (bin, "check async elements");
2690 /* check if all elements managed to commit their state already */
2691 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2692 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2693 * all the elements commited their state while we were doing the state
2694 * change. We will still return ASYNC for consistency but we commit the
2695 * state already so that a _get_state() will return immediately. */
2696 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2698 GST_DEBUG_OBJECT (bin, "async elements commited");
2699 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
2700 GST_CLOCK_TIME_NONE);
2704 bin->priv->pending_async_done = FALSE;
2705 GST_OBJECT_UNLOCK (bin);
2707 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2708 "done changing bin's state from %s to %s, now in %s, ret %s",
2709 gst_element_state_get_name (current),
2710 gst_element_state_get_name (next),
2711 gst_element_state_get_name (GST_STATE (element)),
2712 gst_element_state_change_return_get_name (ret));
2719 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2720 "failure (de)activating src pads");
2721 return GST_STATE_CHANGE_FAILURE;
2726 * This function is a utility event handler for seek events.
2727 * It will send the event to all sinks or sources depending on the
2730 * Applications are free to override this behaviour and
2731 * implement their own seek handler, but this will work for
2732 * pretty much all cases in practice.
2735 gst_bin_send_event (GstElement * element, GstEvent * event)
2737 GstBin *bin = GST_BIN_CAST (element);
2739 gboolean res = TRUE;
2740 gboolean done = FALSE;
2741 GValue data = { 0, };
2743 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2744 iter = gst_bin_iterate_sources (bin);
2745 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2746 GST_EVENT_TYPE_NAME (event));
2748 iter = gst_bin_iterate_sinks (bin);
2749 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2750 GST_EVENT_TYPE_NAME (event));
2754 switch (gst_iterator_next (iter, &data)) {
2755 case GST_ITERATOR_OK:
2757 GstElement *child = g_value_get_object (&data);;
2759 gst_event_ref (event);
2760 res &= gst_element_send_event (child, event);
2761 GST_LOG_OBJECT (child, "After handling %s event: %d",
2762 GST_EVENT_TYPE_NAME (event), res);
2765 case GST_ITERATOR_RESYNC:
2766 gst_iterator_resync (iter);
2769 case GST_ITERATOR_DONE:
2772 case GST_ITERATOR_ERROR:
2773 g_assert_not_reached ();
2777 g_value_unset (&data);
2778 gst_iterator_free (iter);
2779 gst_event_unref (event);
2784 /* this is the function called by the threadpool. When async elements commit
2785 * their state, this function will attempt to bring the bin to the next state.
2788 gst_bin_continue_func (BinContinueData * data)
2791 GstState current, next, pending;
2792 GstStateChange transition;
2795 pending = data->pending;
2797 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2798 GST_STATE_LOCK (bin);
2800 GST_DEBUG_OBJECT (bin, "doing state continue");
2801 GST_OBJECT_LOCK (bin);
2803 /* if a new state change happened after this thread was scheduled, we return
2805 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2808 current = GST_STATE (bin);
2809 next = GST_STATE_GET_NEXT (current, pending);
2810 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2812 GST_STATE_NEXT (bin) = next;
2813 GST_STATE_PENDING (bin) = pending;
2815 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2816 GST_OBJECT_UNLOCK (bin);
2818 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2819 "continue state change %s to %s, final %s",
2820 gst_element_state_get_name (current),
2821 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2823 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2825 GST_STATE_UNLOCK (bin);
2826 GST_DEBUG_OBJECT (bin, "state continue done");
2828 gst_object_unref (bin);
2829 g_slice_free (BinContinueData, data);
2834 GST_OBJECT_UNLOCK (bin);
2835 GST_STATE_UNLOCK (bin);
2836 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2837 gst_object_unref (bin);
2838 g_slice_free (BinContinueData, data);
2843 static GstBusSyncReply
2844 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2846 GstBinClass *bclass;
2848 bclass = GST_BIN_GET_CLASS (bin);
2849 if (bclass->handle_message)
2850 bclass->handle_message (bin, message);
2852 gst_message_unref (message);
2854 return GST_BUS_DROP;
2858 bin_push_state_continue (BinContinueData * data)
2865 klass = GST_BIN_GET_CLASS (bin);
2867 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2868 g_thread_pool_push (klass->pool, data, NULL);
2871 /* an element started an async state change, if we were not busy with a state
2872 * change, we perform a lost state.
2873 * This function is called with the OBJECT lock.
2876 bin_handle_async_start (GstBin * bin)
2878 GstState old_state, new_state;
2880 GstMessage *amessage = NULL;
2882 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2885 /* get our toplevel state */
2886 toplevel = BIN_IS_TOPLEVEL (bin);
2888 /* prepare an ASYNC_START message, we always post the start message even if we
2889 * are busy with a state change or when we are NO_PREROLL. */
2891 /* non toplevel bin, prepare async-start for the parent */
2892 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
2894 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2897 /* async starts are ignored when we are NO_PREROLL */
2898 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2899 goto was_no_preroll;
2901 old_state = GST_STATE (bin);
2903 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2904 * PLAYING after optionally redistributing the base_time. */
2905 if (old_state > GST_STATE_PAUSED)
2906 new_state = GST_STATE_PAUSED;
2908 new_state = old_state;
2910 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2911 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2912 gst_element_state_get_name (new_state));
2914 GST_STATE (bin) = new_state;
2915 GST_STATE_NEXT (bin) = new_state;
2916 GST_STATE_PENDING (bin) = new_state;
2917 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2918 GST_OBJECT_UNLOCK (bin);
2921 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2926 /* post our ASYNC_START. */
2927 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2928 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2930 GST_OBJECT_LOCK (bin);
2936 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2941 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2942 GST_OBJECT_UNLOCK (bin);
2947 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2948 GST_OBJECT_UNLOCK (bin);
2953 /* this function is called when there are no more async elements in the bin. We
2954 * post a state changed message and an ASYNC_DONE message.
2955 * This function is called with the OBJECT lock.
2958 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2959 gboolean flag_pending, GstClockTime running_time)
2961 GstState current, pending, target;
2962 GstStateChangeReturn old_ret;
2963 GstState old_state, old_next;
2964 gboolean toplevel, state_changed = FALSE;
2965 GstMessage *amessage = NULL;
2966 BinContinueData *cont = NULL;
2968 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2971 pending = GST_STATE_PENDING (bin);
2976 /* check if there is something to commit */
2977 if (pending == GST_STATE_VOID_PENDING)
2978 goto nothing_pending;
2980 old_ret = GST_STATE_RETURN (bin);
2981 GST_STATE_RETURN (bin) = ret;
2983 /* move to the next target state */
2984 target = GST_STATE_TARGET (bin);
2985 pending = GST_STATE_PENDING (bin) = target;
2987 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
2989 old_state = GST_STATE (bin);
2990 /* this is the state we should go to next */
2991 old_next = GST_STATE_NEXT (bin);
2993 if (old_next != GST_STATE_PLAYING) {
2994 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2995 "committing state from %s to %s, old pending %s",
2996 gst_element_state_get_name (old_state),
2997 gst_element_state_get_name (old_next),
2998 gst_element_state_get_name (pending));
3000 /* update current state */
3001 current = GST_STATE (bin) = old_next;
3003 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3004 "setting state from %s to %s, pending %s",
3005 gst_element_state_get_name (old_state),
3006 gst_element_state_get_name (old_state),
3007 gst_element_state_get_name (pending));
3008 current = old_state;
3011 /* get our toplevel state */
3012 toplevel = BIN_IS_TOPLEVEL (bin);
3014 /* see if we reached the final state. If we are not toplevel, we also have to
3015 * stop here, the parent will continue our state. */
3016 if ((pending == current) || !toplevel) {
3017 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3018 "completed state change, pending VOID");
3020 /* mark VOID pending */
3021 pending = GST_STATE_VOID_PENDING;
3022 GST_STATE_PENDING (bin) = pending;
3023 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
3025 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3026 "continue state change, pending %s",
3027 gst_element_state_get_name (pending));
3029 cont = g_slice_new (BinContinueData);
3031 /* ref to the bin */
3032 cont->bin = gst_object_ref (bin);
3033 /* cookie to detect concurrent state change */
3034 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3035 /* pending target state */
3036 cont->pending = pending;
3038 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3039 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3042 if (old_next != GST_STATE_PLAYING) {
3043 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3044 state_changed = TRUE;
3047 GST_OBJECT_UNLOCK (bin);
3049 if (state_changed) {
3050 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3054 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3055 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3056 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3059 GST_OBJECT_LOCK (bin);
3061 /* toplevel, start continue state */
3062 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3063 bin_push_state_continue (cont);
3065 GST_DEBUG_OBJECT (bin, "state change complete");
3066 GST_STATE_BROADCAST (bin);
3072 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3077 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3078 /* if we were busy with a state change and we are requested to flag a
3079 * pending async done, we do so here */
3081 bin->priv->pending_async_done = TRUE;
3086 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3092 bin_do_eos (GstBin * bin)
3097 GST_OBJECT_LOCK (bin);
3098 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3099 * we forward the EOS message to the parent bin or application
3101 eos = GST_STATE (bin) == GST_STATE_PLAYING
3102 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3103 && is_eos (bin, &seqnum);
3104 GST_OBJECT_UNLOCK (bin);
3107 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3109 GstMessage *tmessage;
3111 /* Clear out any further messages, and reset posted_eos so we can
3112 detect any new EOS that happens (eg, after a seek). Since all
3113 sinks have now posted an EOS, there will be no further EOS events
3114 seen unless there is a new logical EOS */
3115 GST_OBJECT_LOCK (bin);
3116 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3117 bin->priv->posted_eos = FALSE;
3118 GST_OBJECT_UNLOCK (bin);
3120 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3121 gst_message_set_seqnum (tmessage, seqnum);
3122 GST_DEBUG_OBJECT (bin,
3123 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3124 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3128 /* must be called with the object lock. This function releases the lock to post
3131 bin_do_message_forward (GstBin * bin, GstMessage * message)
3133 if (bin->priv->message_forward) {
3134 GstMessage *forwarded;
3136 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3137 GST_MESSAGE_TYPE_NAME (message));
3138 GST_OBJECT_UNLOCK (bin);
3140 /* we need to convert these messages to element messages so that our parent
3141 * bin can easily ignore them and so that the application can easily
3142 * distinguish between the internally forwarded and the real messages. */
3143 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3144 gst_structure_new ("GstBinForwarded",
3145 "message", GST_TYPE_MESSAGE, message, NULL));
3147 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3149 GST_OBJECT_LOCK (bin);
3153 /* handle child messages:
3155 * This method is called synchronously when a child posts a message on
3158 * GST_MESSAGE_EOS: This message is only posted by sinks
3159 * in the PLAYING state. If all sinks posted the EOS message, post
3162 * GST_MESSAGE_STATE_DIRTY: Deprecated
3164 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3165 * element posts segment_start twice, only the last message is kept.
3167 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3168 * with the segment_done message. If there are no more segment_start
3169 * messages, post segment_done message upwards.
3171 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3172 * Whenever someone performs a duration query on the bin, we store the
3173 * result so we can answer it quicker the next time. Any element that
3174 * changes its duration marks our cached values invalid.
3175 * This message is also posted upwards. This is currently disabled
3176 * because too many elements don't post DURATION messages when the
3179 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3180 * can no longer provide a clock. The default bin behaviour is to
3181 * check if the lost clock was the one provided by the bin. If so and
3182 * we are currently in the PLAYING state, we forward the message to
3184 * This message is also generated when we remove a clock provider from
3185 * a bin. If this message is received by the application, it should
3186 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3187 * and a new base_time distribution.
3189 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3190 * can provide a clock. This mostly happens when we add a new clock
3191 * provider to the bin. The default behaviour of the bin is to mark the
3192 * currently selected clock as dirty, which will perform a clock
3193 * recalculation the next time we are asked to provide a clock.
3194 * This message is never sent to the application but is forwarded to
3197 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3198 * the state of the element and the fact that the element will need a
3199 * new base_time. This message is not forwarded to the application.
3201 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3202 * element when it posted ASYNC_START. If all elements are done, post a
3203 * ASYNC_DONE message to the parent.
3205 * OTHER: post upwards.
3208 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3211 GstMessageType type;
3212 GstMessage *tmessage;
3215 src = GST_MESSAGE_SRC (message);
3216 type = GST_MESSAGE_TYPE (message);
3218 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3219 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3220 GST_MESSAGE_TYPE_NAME (message));
3223 case GST_MESSAGE_ERROR:
3225 GST_OBJECT_LOCK (bin);
3227 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3228 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3229 GST_STATE_BROADCAST (bin);
3230 GST_OBJECT_UNLOCK (bin);
3234 case GST_MESSAGE_EOS:
3237 /* collect all eos messages from the children */
3238 GST_OBJECT_LOCK (bin);
3239 bin_do_message_forward (bin, message);
3240 /* ref message for future use */
3241 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3242 GST_OBJECT_UNLOCK (bin);
3247 case GST_MESSAGE_STATE_DIRTY:
3249 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3252 gst_message_unref (message);
3255 case GST_MESSAGE_SEGMENT_START:{
3256 gboolean post = FALSE;
3260 gst_message_parse_segment_start (message, &format, &position);
3261 seqnum = gst_message_get_seqnum (message);
3263 GST_OBJECT_LOCK (bin);
3264 bin_do_message_forward (bin, message);
3265 /* if this is the first segment-start, post to parent but not to the
3267 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3268 (GST_OBJECT_PARENT (bin) != NULL)) {
3271 /* replace any previous segment_start message from this source
3272 * with the new segment start message */
3273 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3274 GST_OBJECT_UNLOCK (bin);
3276 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3278 gst_message_set_seqnum (tmessage, seqnum);
3280 /* post segment start with initial format and position. */
3281 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3283 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3287 case GST_MESSAGE_SEGMENT_DONE:
3289 gboolean post = FALSE;
3293 gst_message_parse_segment_done (message, &format, &position);
3294 seqnum = gst_message_get_seqnum (message);
3296 GST_OBJECT_LOCK (bin);
3297 bin_do_message_forward (bin, message);
3298 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3299 /* if there are no more segment_start messages, everybody posted
3300 * a segment_done and we can post one on the bus. */
3302 /* we don't care who still has a pending segment start */
3303 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3306 /* remove all old segment_done messages */
3307 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3309 GST_OBJECT_UNLOCK (bin);
3311 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3313 gst_message_set_seqnum (tmessage, seqnum);
3315 /* post segment done with latest format and position. */
3316 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3318 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3322 case GST_MESSAGE_DURATION:
3324 /* remove all cached duration messages, next time somebody asks
3325 * for duration, we will recalculate. */
3326 GST_OBJECT_LOCK (bin);
3327 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3328 GST_OBJECT_UNLOCK (bin);
3331 case GST_MESSAGE_CLOCK_LOST:
3333 GstClock **provided_clock_p;
3334 GstElement **clock_provider_p;
3335 gboolean playing, provided, forward;
3338 gst_message_parse_clock_lost (message, &clock);
3340 GST_OBJECT_LOCK (bin);
3341 bin->clock_dirty = TRUE;
3342 /* if we lost the clock that we provided, post to parent but
3343 * only if we are PLAYING. */
3344 provided = (clock == bin->provided_clock);
3345 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3346 forward = playing & provided;
3348 GST_DEBUG_OBJECT (bin,
3349 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3350 bin->provided_clock, bin->clock_provider);
3351 provided_clock_p = &bin->provided_clock;
3352 clock_provider_p = &bin->clock_provider;
3353 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3354 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3356 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3357 provided, playing, forward);
3358 GST_OBJECT_UNLOCK (bin);
3364 gst_message_unref (message);
3367 case GST_MESSAGE_CLOCK_PROVIDE:
3371 GST_OBJECT_LOCK (bin);
3372 bin->clock_dirty = TRUE;
3373 /* a new clock is available, post to parent but not
3374 * to the application */
3375 forward = GST_OBJECT_PARENT (bin) != NULL;
3376 GST_OBJECT_UNLOCK (bin);
3382 gst_message_unref (message);
3385 case GST_MESSAGE_ASYNC_START:
3389 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3390 src ? GST_OBJECT_NAME (src) : "(NULL)");
3392 GST_OBJECT_LOCK (bin);
3393 bin_do_message_forward (bin, message);
3395 /* we ignore the message if we are going to <= READY */
3396 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3397 goto ignore_start_message;
3399 /* takes ownership of the message */
3400 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3402 bin_handle_async_start (bin);
3403 GST_OBJECT_UNLOCK (bin);
3406 ignore_start_message:
3408 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3409 gst_element_state_get_name (target));
3410 GST_OBJECT_UNLOCK (bin);
3411 gst_message_unref (message);
3415 case GST_MESSAGE_ASYNC_DONE:
3417 GstClockTime running_time;
3420 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3421 src ? GST_OBJECT_NAME (src) : "(NULL)");
3423 gst_message_parse_async_done (message, &running_time);
3425 GST_OBJECT_LOCK (bin);
3426 bin_do_message_forward (bin, message);
3428 /* ignore messages if we are shutting down */
3429 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3430 goto ignore_done_message;
3432 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3433 /* if there are no more ASYNC_START messages, everybody posted
3434 * a ASYNC_DONE and we can post one on the bus. When checking, we
3435 * don't care who still has a pending ASYNC_START */
3436 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3437 /* nothing found, remove all old ASYNC_DONE messages */
3438 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3440 GST_DEBUG_OBJECT (bin, "async elements commited");
3441 /* when we get an async done message when a state change was busy, we
3442 * need to set the pending_done flag so that at the end of the state
3443 * change we can see if we need to verify pending async elements, hence
3444 * the TRUE argument here. */
3445 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
3448 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3450 GST_OBJECT_UNLOCK (bin);
3453 ignore_done_message:
3455 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3456 gst_element_state_get_name (target));
3457 GST_OBJECT_UNLOCK (bin);
3458 gst_message_unref (message);
3462 case GST_MESSAGE_STRUCTURE_CHANGE:
3466 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3468 GST_OBJECT_LOCK (bin);
3470 /* while the pad is busy, avoid following it when doing state changes.
3471 * Don't update the cookie yet, we will do that after the structure
3472 * change finished and we are ready to inspect the new updated
3474 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3477 /* a pad link/unlink ended, signal the state change iterator that we
3478 * need to resync by updating the structure_cookie. */
3479 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3480 GST_MESSAGE_STRUCTURE_CHANGE);
3481 bin->priv->structure_cookie++;
3483 GST_OBJECT_UNLOCK (bin);
3486 gst_message_unref (message);
3497 /* Send all other messages upward */
3498 GST_DEBUG_OBJECT (bin, "posting message upward");
3499 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3504 /* generic struct passed to all query fold methods */
3513 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3514 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3516 /* for duration/position we collect all durations/positions and take
3517 * the MAX of all valid results */
3519 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3527 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3529 GstElement *item = g_value_get_object (vitem);
3531 if (gst_element_query (item, fold->query)) {
3534 g_value_set_boolean (ret, TRUE);
3536 gst_query_parse_duration (fold->query, NULL, &duration);
3538 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3540 if (duration > fold->max)
3541 fold->max = duration;
3548 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3552 gst_query_parse_duration (fold->query, &format, NULL);
3553 /* store max in query result */
3554 gst_query_set_duration (fold->query, format, fold->max);
3556 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3559 GST_OBJECT_LOCK (bin);
3560 bin->messages = g_list_prepend (bin->messages,
3561 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3562 GST_OBJECT_UNLOCK (bin);
3566 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3568 GstElement *item = g_value_get_object (vitem);
3570 if (gst_element_query (item, fold->query)) {
3573 g_value_set_boolean (ret, TRUE);
3575 gst_query_parse_position (fold->query, NULL, &position);
3577 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3579 if (position > fold->max)
3580 fold->max = position;
3587 bin_query_position_done (GstBin * bin, QueryFold * fold)
3591 gst_query_parse_position (fold->query, &format, NULL);
3592 /* store max in query result */
3593 gst_query_set_position (fold->query, format, fold->max);
3595 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3599 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3601 GstElement *item = g_value_get_object (vitem);
3603 if (gst_element_query (item, fold->query)) {
3604 GstClockTime min, max;
3607 gst_query_parse_latency (fold->query, &live, &min, &max);
3609 GST_DEBUG_OBJECT (item,
3610 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3611 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3613 /* for the combined latency we collect the MAX of all min latencies and
3614 * the MIN of all max latencies */
3616 if (min > fold->min)
3618 if (fold->max == -1)
3620 else if (max < fold->max)
3622 if (fold->live == FALSE)
3626 g_value_set_boolean (ret, FALSE);
3627 GST_DEBUG_OBJECT (item, "failed query");
3634 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3636 /* store max in query result */
3637 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3639 GST_DEBUG_OBJECT (bin,
3640 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3641 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3645 /* generic fold, return first valid result */
3647 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3649 GstElement *item = g_value_get_object (vitem);
3652 if ((res = gst_element_query (item, fold->query))) {
3653 g_value_set_boolean (ret, TRUE);
3654 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3657 /* and stop as soon as we have a valid result */
3662 gst_bin_query (GstElement * element, GstQuery * query)
3664 GstBin *bin = GST_BIN_CAST (element);
3666 gboolean res = FALSE;
3667 GstIteratorFoldFunction fold_func;
3668 QueryInitFunction fold_init = NULL;
3669 QueryDoneFunction fold_done = NULL;
3670 QueryFold fold_data;
3673 switch (GST_QUERY_TYPE (query)) {
3674 case GST_QUERY_DURATION:
3679 gst_query_parse_duration (query, &qformat, NULL);
3681 /* find cached duration query */
3682 GST_OBJECT_LOCK (bin);
3683 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3684 GstMessage *message = (GstMessage *) cached->data;
3686 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3687 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3691 gst_message_parse_duration (message, &format, &duration);
3693 /* if cached same format, copy duration in query result */
3694 if (format == qformat) {
3695 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3697 GST_OBJECT_UNLOCK (bin);
3699 gst_query_set_duration (query, qformat, duration);
3705 GST_OBJECT_UNLOCK (bin);
3706 /* no cached value found, iterate and collect durations */
3707 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3708 fold_init = bin_query_min_max_init;
3709 fold_done = bin_query_duration_done;
3712 case GST_QUERY_POSITION:
3714 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3715 fold_init = bin_query_min_max_init;
3716 fold_done = bin_query_position_done;
3719 case GST_QUERY_LATENCY:
3721 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3722 fold_init = bin_query_min_max_init;
3723 fold_done = bin_query_latency_done;
3728 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3732 fold_data.query = query;
3734 /* set the result of the query to FALSE initially */
3735 g_value_init (&ret, G_TYPE_BOOLEAN);
3736 g_value_set_boolean (&ret, res);
3738 iter = gst_bin_iterate_sinks (bin);
3739 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3740 query, GST_QUERY_TYPE_NAME (query));
3743 fold_init (bin, &fold_data);
3746 GstIteratorResult ires;
3748 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3751 case GST_ITERATOR_RESYNC:
3752 gst_iterator_resync (iter);
3754 fold_init (bin, &fold_data);
3755 g_value_set_boolean (&ret, res);
3757 case GST_ITERATOR_OK:
3758 case GST_ITERATOR_DONE:
3759 res = g_value_get_boolean (&ret);
3760 if (fold_done != NULL && res)
3761 fold_done (bin, &fold_data);
3769 gst_iterator_free (iter);
3772 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3778 compare_name (const GValue * velement, const gchar * name)
3781 GstElement *element = g_value_get_object (velement);
3783 GST_OBJECT_LOCK (element);
3784 eq = strcmp (GST_ELEMENT_NAME (element), name);
3785 GST_OBJECT_UNLOCK (element);
3791 * gst_bin_get_by_name:
3793 * @name: the element name to search for
3795 * Gets the element with the given name from a bin. This
3796 * function recurses into child bins.
3798 * Returns NULL if no element with the given name is found in the bin.
3800 * MT safe. Caller owns returned reference.
3802 * Returns: (transfer full): the #GstElement with the given name, or NULL
3805 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3807 GstIterator *children;
3808 GValue result = { 0, };
3809 GstElement *element;
3812 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3814 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3815 GST_ELEMENT_NAME (bin), name);
3817 children = gst_bin_iterate_recurse (bin);
3818 found = gst_iterator_find_custom (children,
3819 (GCompareFunc) compare_name, &result, (gpointer) name);
3820 gst_iterator_free (children);
3823 element = g_value_dup_object (&result);
3824 g_value_unset (&result);
3833 * gst_bin_get_by_name_recurse_up:
3835 * @name: the element name to search for
3837 * Gets the element with the given name from this bin. If the
3838 * element is not found, a recursion is performed on the parent bin.
3841 * - no element with the given name is found in the bin
3843 * MT safe. Caller owns returned reference.
3845 * Returns: (transfer full): the #GstElement with the given name, or NULL
3848 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3852 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3853 g_return_val_if_fail (name != NULL, NULL);
3855 result = gst_bin_get_by_name (bin, name);
3860 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3862 if (GST_IS_BIN (parent)) {
3863 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3865 gst_object_unref (parent);
3873 compare_interface (const GValue * velement, GValue * interface)
3875 GstElement *element = g_value_get_object (velement);
3876 GType interface_type = (GType) g_value_get_pointer (interface);
3879 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3888 * gst_bin_get_by_interface:
3890 * @iface: the #GType of an interface
3892 * Looks for an element inside the bin that implements the given
3893 * interface. If such an element is found, it returns the element.
3894 * You can cast this element to the given interface afterwards. If you want
3895 * all elements that implement the interface, use
3896 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3898 * MT safe. Caller owns returned reference.
3900 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3903 gst_bin_get_by_interface (GstBin * bin, GType iface)
3905 GstIterator *children;
3906 GValue result = { 0, };
3907 GstElement *element;
3909 GValue viface = { 0, };
3911 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3912 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3914 g_value_init (&viface, G_TYPE_POINTER);
3915 g_value_set_pointer (&viface, (gpointer) iface);
3917 children = gst_bin_iterate_recurse (bin);
3918 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3920 gst_iterator_free (children);
3923 element = g_value_dup_object (&result);
3924 g_value_unset (&result);
3928 g_value_unset (&viface);
3934 * gst_bin_iterate_all_by_interface:
3936 * @iface: the #GType of an interface
3938 * Looks for all elements inside the bin that implements the given
3939 * interface. You can safely cast all returned elements to the given interface.
3940 * The function recurses inside child bins. The iterator will yield a series
3941 * of #GstElement that should be unreffed after use.
3943 * Each element yielded by the iterator will have its refcount increased, so
3946 * MT safe. Caller owns returned value.
3948 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3949 * in the bin implementing the given interface, or NULL
3952 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3954 GstIterator *children;
3955 GstIterator *result;
3956 GValue viface = { 0, };
3958 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3959 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3961 g_value_init (&viface, G_TYPE_POINTER);
3962 g_value_set_pointer (&viface, (gpointer) iface);
3964 children = gst_bin_iterate_recurse (bin);
3965 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3968 g_value_unset (&viface);