3 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
4 * 2004 Wim Taymans <wim.taymans@gmail.com>
6 * gstbin.c: GstBin container object and support code
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
28 * @short_description: Base class and element that can contain other elements
30 * #GstBin is an element that can contain other #GstElement, allowing them to be
32 * Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
33 * This makes the bin look like any other elements and enables creation of
34 * higher-level abstraction elements.
36 * A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
37 * want to create a toplevel bin because a normal bin doesn't have a bus or
38 * handle clock distribution of its own.
40 * After the bin has been created you will typically add elements to it with
41 * gst_bin_add(). You can remove elements with gst_bin_remove().
43 * An element can be retrieved from a bin with gst_bin_get_by_name(), using the
44 * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
45 * purposes and will query the parent bins when the element is not found in the
48 * An iterator of elements in a bin can be retrieved with
49 * gst_bin_iterate_elements(). Various other iterators exist to retrieve the
52 * gst_object_unref() is used to drop your reference to the bin.
54 * The #GstBin::element-added signal is fired whenever a new element is added to
55 * the bin. Likewise the #GstBin::element-removed signal is fired whenever an
56 * element is removed from the bin.
58 * <refsect2><title>Notes</title>
60 * A #GstBin internally intercepts every #GstMessage posted by its children and
61 * implements the following default behaviour for each of them:
64 * <term>GST_MESSAGE_EOS</term>
65 * <listitem><para>This message is only posted by sinks in the PLAYING
66 * state. If all sinks posted the EOS message, this bin will post and EOS
67 * message upwards.</para></listitem>
70 * <term>GST_MESSAGE_SEGMENT_START</term>
71 * <listitem><para>just collected and never forwarded upwards.
72 * The messages are used to decide when all elements have completed playback
73 * of their segment.</para></listitem>
76 * <term>GST_MESSAGE_SEGMENT_DONE</term>
77 * <listitem><para> Is posted by #GstBin when all elements that posted
78 * a SEGMENT_START have posted a SEGMENT_DONE.</para></listitem>
81 * <term>GST_MESSAGE_DURATION_CHANGED</term>
82 * <listitem><para> Is posted by an element that detected a change
83 * in the stream duration. The default bin behaviour is to clear any
84 * cached duration values so that the next duration query will perform
85 * a full duration recalculation. The duration change is posted to the
86 * application so that it can refetch the new duration with a duration
87 * query. Note that these messages can be posted before the bin is
88 * prerolled, in which case the duration query might fail.
92 * <term>GST_MESSAGE_CLOCK_LOST</term>
93 * <listitem><para> This message is posted by an element when it
94 * can no longer provide a clock. The default bin behaviour is to
95 * check if the lost clock was the one provided by the bin. If so and
96 * the bin is currently in the PLAYING state, the message is forwarded to
98 * This message is also generated when a clock provider is removed from
99 * the bin. If this message is received by the application, it should
100 * PAUSE the pipeline and set it back to PLAYING to force a new clock
105 * <term>GST_MESSAGE_CLOCK_PROVIDE</term>
106 * <listitem><para> This message is generated when an element
107 * can provide a clock. This mostly happens when a new clock
108 * provider is added to the bin. The default behaviour of the bin is to
109 * mark the currently selected clock as dirty, which will perform a clock
110 * recalculation the next time the bin is asked to provide a clock.
111 * This message is never sent tot the application but is forwarded to
112 * the parent of the bin.
116 * <term>OTHERS</term>
117 * <listitem><para> posted upwards.</para></listitem>
122 * A #GstBin implements the following default behaviour for answering to a
126 * <term>GST_QUERY_DURATION</term>
127 * <listitem><para>If the query has been asked before with the same format
128 * and the bin is a toplevel bin (ie. has no parent),
129 * use the cached previous value. If no previous value was cached, the
130 * query is sent to all sink elements in the bin and the MAXIMUM of all
131 * values is returned. If the bin is a toplevel bin the value is cached.
132 * If no sinks are available in the bin, the query fails.
136 * <term>GST_QUERY_POSITION</term>
137 * <listitem><para>The query is sent to all sink elements in the bin and the
138 * MAXIMUM of all values is returned. If no sinks are available in the bin,
143 * <term>OTHERS</term>
144 * <listitem><para>the query is forwarded to all sink elements, the result
145 * of the first sink that answers the query successfully is returned. If no
146 * sink is in the bin, the query fails.</para></listitem>
150 * A #GstBin will by default forward any event sent to it to all sink elements.
151 * If all the sinks return %TRUE, the bin will also return %TRUE, else %FALSE is
152 * returned. If no sinks are in the bin, the event handler will return %TRUE.
158 #include "gst_private.h"
160 #include "gstevent.h"
163 #include "gsterror.h"
165 #include "gstutils.h"
166 #include "gstchildproxy.h"
168 GST_DEBUG_CATEGORY_STATIC (bin_debug);
169 #define GST_CAT_DEFAULT bin_debug
171 /* a bin is toplevel if it has no parent or when it is configured to behave like
173 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
175 #define GST_BIN_GET_PRIVATE(obj) \
176 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
178 struct _GstBinPrivate
180 gboolean asynchandling;
181 /* if we get an ASYNC_DONE message from ourselves, this means that the
182 * subclass will simulate ASYNC behaviour without having ASYNC children. When
183 * such an ASYNC_DONE message is posted while we are doing a state change, we
184 * have to process the message after finishing the state change even when no
185 * child returned GST_STATE_CHANGE_ASYNC. */
186 gboolean pending_async_done;
188 guint32 structure_cookie;
195 /* forward messages from our children */
196 gboolean message_forward;
199 gboolean posted_playing;
209 static void gst_bin_dispose (GObject * object);
211 static void gst_bin_set_property (GObject * object, guint prop_id,
212 const GValue * value, GParamSpec * pspec);
213 static void gst_bin_get_property (GObject * object, guint prop_id,
214 GValue * value, GParamSpec * pspec);
216 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
217 GstStateChange transition);
218 static gboolean gst_bin_post_message (GstElement * element, GstMessage * msg);
219 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
220 GstState * state, GstState * pending, GstClockTime timeout);
221 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
222 gboolean flag_pending, GstClockTime running_time);
223 static void bin_handle_async_start (GstBin * bin);
224 static void bin_push_state_continue (BinContinueData * data);
225 static void bin_do_eos (GstBin * bin);
227 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
228 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
229 static void gst_bin_update_context (GstBin * bin, GstContext * context);
230 static void gst_bin_update_context_unlocked (GstBin * bin,
231 GstContext * context);
234 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
235 static GstIndex *gst_bin_get_index_func (GstElement * element);
238 static GstClock *gst_bin_provide_clock_func (GstElement * element);
239 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
241 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
242 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
243 static GstBusSyncReply bin_bus_handler (GstBus * bus,
244 GstMessage * message, GstBin * bin);
245 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
246 static void gst_bin_set_context (GstElement * element, GstContext * context);
248 static gboolean gst_bin_do_latency_func (GstBin * bin);
250 static void bin_remove_messages (GstBin * bin, GstObject * src,
251 GstMessageType types);
252 static void gst_bin_continue_func (BinContinueData * data);
253 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
254 static gint bin_element_is_src (GstElement * child, GstBin * bin);
256 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
258 /* Bin signals and properties */
267 #define DEFAULT_ASYNC_HANDLING FALSE
268 #define DEFAULT_MESSAGE_FORWARD FALSE
274 PROP_MESSAGE_FORWARD,
278 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
280 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
284 static const GInterfaceInfo iface_info = { \
285 gst_bin_child_proxy_init, \
289 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
291 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
292 "debugging info for the 'bin' container element"); \
296 #define gst_bin_parent_class parent_class
297 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
300 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
306 bin = GST_BIN_CAST (child_proxy);
308 GST_OBJECT_LOCK (bin);
309 if ((res = g_list_nth_data (bin->children, index)))
310 gst_object_ref (res);
311 GST_OBJECT_UNLOCK (bin);
313 return (GObject *) res;
317 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
322 bin = GST_BIN_CAST (child_proxy);
324 GST_OBJECT_LOCK (bin);
325 num = bin->numchildren;
326 GST_OBJECT_UNLOCK (bin);
332 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
334 GstChildProxyInterface *iface = g_iface;
336 iface->get_children_count = gst_bin_child_proxy_get_children_count;
337 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
341 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
342 GValue * return_accu, const GValue * handler_return, gpointer dummy)
346 myboolean = g_value_get_boolean (handler_return);
347 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
348 g_value_set_boolean (return_accu, myboolean);
350 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
357 gst_bin_class_init (GstBinClass * klass)
359 GObjectClass *gobject_class;
360 GstElementClass *gstelement_class;
363 gobject_class = (GObjectClass *) klass;
364 gstelement_class = (GstElementClass *) klass;
366 g_type_class_add_private (klass, sizeof (GstBinPrivate));
368 gobject_class->set_property = gst_bin_set_property;
369 gobject_class->get_property = gst_bin_get_property;
372 * GstBin:async-handling:
374 * If set to %TRUE, the bin will handle asynchronous state changes.
375 * This should be used only if the bin subclass is modifying the state
376 * 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 emitted 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
421 gst_bin_signals[DO_LATENCY] =
422 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
423 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
424 _gst_boolean_accumulator, NULL, g_cclosure_marshal_generic,
425 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
428 * GstBin:message-forward:
430 * Forward all children messages, even those that would normally be filtered by
431 * the bin. This can be interesting when one wants to be notified of the EOS
432 * state of individual elements, for example.
434 * The messages are converted to an ELEMENT message with the bin as the
435 * source. The structure of the message is named 'GstBinForwarded' and contains
436 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
439 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
440 g_param_spec_boolean ("message-forward", "Message Forward",
441 "Forwards all children messages",
442 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
444 gobject_class->dispose = gst_bin_dispose;
446 gst_element_class_set_static_metadata (gstelement_class, "Generic bin",
448 "Simple container object",
449 "Erik Walthinsen <omega@cse.ogi.edu>,"
450 "Wim Taymans <wim.taymans@gmail.com>");
452 gstelement_class->change_state =
453 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
454 gstelement_class->post_message = GST_DEBUG_FUNCPTR (gst_bin_post_message);
455 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
457 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
458 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
460 gstelement_class->provide_clock =
461 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
462 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
464 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
465 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
466 gstelement_class->set_context = GST_DEBUG_FUNCPTR (gst_bin_set_context);
468 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
469 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
470 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
472 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
474 GST_DEBUG ("creating bin thread pool");
477 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
479 g_critical ("could not alloc threadpool %s", err->message);
484 gst_bin_init (GstBin * bin)
488 bin->numchildren = 0;
489 bin->children = NULL;
490 bin->children_cookie = 0;
491 bin->messages = NULL;
492 bin->provided_clock = NULL;
493 bin->clock_dirty = FALSE;
495 /* Set up a bus for listening to child elements */
496 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
497 bin->child_bus = bus;
498 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
500 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin,
503 bin->priv = GST_BIN_GET_PRIVATE (bin);
504 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
505 bin->priv->structure_cookie = 0;
506 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
510 gst_bin_dispose (GObject * object)
512 GstBin *bin = GST_BIN_CAST (object);
513 GstBus **child_bus_p = &bin->child_bus;
514 GstClock **provided_clock_p = &bin->provided_clock;
515 GstElement **clock_provider_p = &bin->clock_provider;
517 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
519 GST_OBJECT_LOCK (object);
520 gst_object_replace ((GstObject **) child_bus_p, NULL);
521 gst_object_replace ((GstObject **) provided_clock_p, NULL);
522 gst_object_replace ((GstObject **) clock_provider_p, NULL);
523 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
524 GST_OBJECT_UNLOCK (object);
526 while (bin->children) {
527 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
529 if (G_UNLIKELY (bin->children != NULL)) {
530 g_critical ("could not remove elements from bin '%s'",
531 GST_STR_NULL (GST_OBJECT_NAME (object)));
534 G_OBJECT_CLASS (parent_class)->dispose (object);
539 * @name: (allow-none): the name of the new bin
541 * Creates a new bin with the given name.
543 * Returns: (transfer floating): a new #GstBin
546 gst_bin_new (const gchar * name)
548 return gst_element_factory_make ("bin", name);
552 gst_bin_set_property (GObject * object, guint prop_id,
553 const GValue * value, GParamSpec * pspec)
557 gstbin = GST_BIN_CAST (object);
560 case PROP_ASYNC_HANDLING:
561 GST_OBJECT_LOCK (gstbin);
562 gstbin->priv->asynchandling = g_value_get_boolean (value);
563 GST_OBJECT_UNLOCK (gstbin);
565 case PROP_MESSAGE_FORWARD:
566 GST_OBJECT_LOCK (gstbin);
567 gstbin->priv->message_forward = g_value_get_boolean (value);
568 GST_OBJECT_UNLOCK (gstbin);
571 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
577 gst_bin_get_property (GObject * object, guint prop_id,
578 GValue * value, GParamSpec * pspec)
582 gstbin = GST_BIN_CAST (object);
585 case PROP_ASYNC_HANDLING:
586 GST_OBJECT_LOCK (gstbin);
587 g_value_set_boolean (value, gstbin->priv->asynchandling);
588 GST_OBJECT_UNLOCK (gstbin);
590 case PROP_MESSAGE_FORWARD:
591 GST_OBJECT_LOCK (gstbin);
592 g_value_set_boolean (value, gstbin->priv->message_forward);
593 GST_OBJECT_UNLOCK (gstbin);
596 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
602 /* return the cached index */
604 gst_bin_get_index_func (GstElement * element)
609 bin = GST_BIN_CAST (element);
611 GST_OBJECT_LOCK (bin);
612 if ((result = bin->priv->index))
613 gst_object_ref (result);
614 GST_OBJECT_UNLOCK (bin);
619 /* set the index on all elements in this bin
624 gst_bin_set_index_func (GstElement * element, GstIndex * index)
630 GValue data = { 0, };
632 bin = GST_BIN_CAST (element);
634 GST_OBJECT_LOCK (bin);
635 old = bin->priv->index;
636 if (G_UNLIKELY (old == index))
639 gst_object_ref (index);
640 bin->priv->index = index;
641 GST_OBJECT_UNLOCK (bin);
644 gst_object_unref (old);
646 it = gst_bin_iterate_elements (bin);
648 /* set the index on all elements in the bin */
651 switch (gst_iterator_next (it, &data)) {
652 case GST_ITERATOR_OK:
654 GstElement *child = g_value_get_object (&data);
656 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
657 GST_ELEMENT_NAME (child));
658 gst_element_set_index (child, index);
660 g_value_reset (&data);
663 case GST_ITERATOR_RESYNC:
664 GST_DEBUG_OBJECT (bin, "iterator doing resync");
665 gst_iterator_resync (it);
668 case GST_ITERATOR_DONE:
669 GST_DEBUG_OBJECT (bin, "iterator done");
674 g_value_unset (&data);
675 gst_iterator_free (it);
680 GST_DEBUG_OBJECT (bin, "index was already set");
681 GST_OBJECT_UNLOCK (bin);
687 /* set the clock on all elements in this bin
692 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
698 GValue data = { 0, };
700 bin = GST_BIN_CAST (element);
702 it = gst_bin_iterate_elements (bin);
706 switch (gst_iterator_next (it, &data)) {
707 case GST_ITERATOR_OK:
709 GstElement *child = g_value_get_object (&data);
711 res &= gst_element_set_clock (child, clock);
713 g_value_reset (&data);
716 case GST_ITERATOR_RESYNC:
717 GST_DEBUG_OBJECT (bin, "iterator doing resync");
718 gst_iterator_resync (it);
722 case GST_ITERATOR_DONE:
723 GST_DEBUG_OBJECT (bin, "iterator done");
728 g_value_unset (&data);
729 gst_iterator_free (it);
732 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
737 /* get the clock for this bin by asking all of the children in this bin
739 * The ref of the returned clock in increased so unref after usage.
741 * We loop the elements in state order and pick the last clock we can
742 * get. This makes sure we get a clock from the source.
747 gst_bin_provide_clock_func (GstElement * element)
749 GstClock *result = NULL;
750 GstElement *provider = NULL;
755 GstClock **provided_clock_p;
756 GstElement **clock_provider_p;
758 bin = GST_BIN_CAST (element);
760 GST_OBJECT_LOCK (bin);
761 if (!bin->clock_dirty)
764 GST_DEBUG_OBJECT (bin, "finding new clock");
766 it = gst_bin_sort_iterator_new (bin);
767 GST_OBJECT_UNLOCK (bin);
771 switch (gst_iterator_next (it, &val)) {
772 case GST_ITERATOR_OK:
774 GstElement *child = g_value_get_object (&val);
777 clock = gst_element_provide_clock (child);
779 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
780 clock, GST_ELEMENT_NAME (child));
782 gst_object_unref (result);
783 gst_object_unref (provider);
786 provider = gst_object_ref (child);
789 g_value_reset (&val);
792 case GST_ITERATOR_RESYNC:
793 gst_iterator_resync (it);
796 case GST_ITERATOR_DONE:
801 g_value_unset (&val);
802 gst_iterator_free (it);
804 GST_OBJECT_LOCK (bin);
805 if (!bin->clock_dirty) {
807 gst_object_unref (provider);
809 gst_object_unref (result);
815 provided_clock_p = &bin->provided_clock;
816 clock_provider_p = &bin->clock_provider;
817 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
818 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
819 bin->clock_dirty = FALSE;
820 GST_DEBUG_OBJECT (bin,
821 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
823 /* Provider is not being returned to caller, just the result */
825 gst_object_unref (provider);
826 GST_OBJECT_UNLOCK (bin);
832 if ((result = bin->provided_clock))
833 gst_object_ref (result);
834 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
835 GST_OBJECT_UNLOCK (bin);
842 * functions for manipulating cached messages
847 GstMessageType types;
850 /* check if a message is of given src and type */
852 message_check (GstMessage * message, MessageFind * target)
857 eq &= GST_MESSAGE_SRC (message) == target->src;
859 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
860 GST_LOG ("looking at message %p: %d", message, eq);
866 find_message (GstBin * bin, GstObject * src, GstMessageType types)
874 result = g_list_find_custom (bin->messages, &find,
875 (GCompareFunc) message_check);
878 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
879 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
882 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
883 #ifndef GST_DISABLE_GST_DEBUG
887 for (i = 0; i < 32; i++)
888 if (types & (1U << i))
889 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1U << i));
897 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
900 * A message that is cached and has the same SRC and type is replaced
901 * by the given message.
904 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
910 if ((src = GST_MESSAGE_SRC (message))) {
911 /* first find the previous message posted by this element */
912 if ((previous = find_message (bin, src, types))) {
913 GstMessage *previous_msg;
915 /* if we found a previous message, replace it */
916 previous_msg = previous->data;
917 previous->data = message;
919 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
920 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
921 GST_MESSAGE_TYPE_NAME (message));
923 gst_message_unref (previous_msg);
925 /* keep new message */
926 bin->messages = g_list_prepend (bin->messages, message);
928 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
929 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
932 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
933 GST_MESSAGE_TYPE_NAME (message));
935 gst_message_unref (message);
940 /* with LOCK. Remove all messages of given types */
942 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
950 for (walk = bin->messages; walk; walk = next) {
951 GstMessage *message = (GstMessage *) walk->data;
953 next = g_list_next (walk);
955 if (message_check (message, &find) == 0) {
956 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
957 "deleting message %p of types 0x%08x", message, types);
958 bin->messages = g_list_delete_link (bin->messages, walk);
959 gst_message_unref (message);
961 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
962 "not deleting message %p of type 0x%08x", message,
963 GST_MESSAGE_TYPE (message));
969 /* Check if the bin is EOS. We do this by scanning all sinks and
970 * checking if they posted an EOS message.
972 * call with bin LOCK */
974 is_eos (GstBin * bin, guint32 * seqnum)
981 for (walk = bin->children; walk; walk = g_list_next (walk)) {
984 element = GST_ELEMENT_CAST (walk->data);
985 if (bin_element_is_sink (element, bin) == 0) {
986 /* check if element posted EOS */
988 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
989 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
990 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
993 GST_DEBUG ("sink '%s' did not post EOS yet",
994 GST_ELEMENT_NAME (element));
1000 /* FIXME: Some tests (e.g. elements/capsfilter) use
1001 * pipelines with a dangling sinkpad but no sink element.
1002 * These tests assume that no EOS message is ever
1003 * posted on the bus so let's keep that behaviour.
1004 * In valid pipelines this doesn't make a difference.
1006 return result && n_eos > 0;
1010 /* Check if the bin is STREAM_START. We do this by scanning all sinks and
1011 * checking if they posted an STREAM_START message.
1013 * call with bin LOCK */
1015 is_stream_start (GstBin * bin, guint32 * seqnum, gboolean * have_group_id,
1021 gboolean first = TRUE, same_group_id = TRUE;
1023 *have_group_id = TRUE;
1026 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1027 GstElement *element;
1029 element = GST_ELEMENT_CAST (walk->data);
1030 if (bin_element_is_sink (element, bin) == 0) {
1031 /* check if element posted STREAM_START */
1033 find_message (bin, GST_OBJECT_CAST (element),
1034 GST_MESSAGE_STREAM_START))) {
1035 GST_DEBUG ("sink '%s' posted STREAM_START", GST_ELEMENT_NAME (element));
1036 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1037 if (gst_message_parse_group_id (GST_MESSAGE_CAST (msgs->data),
1041 *group_id = tmp_group_id;
1043 if (tmp_group_id != *group_id)
1044 same_group_id = FALSE;
1047 *have_group_id = FALSE;
1050 GST_DEBUG ("sink '%s' did not post STREAM_START yet",
1051 GST_ELEMENT_NAME (element));
1058 /* If all have a group_id we only consider this stream started
1059 * if all group ids were the same and all sinks posted a stream-start
1062 return same_group_id && result;
1063 /* otherwise consider this stream started after all sinks
1064 * have reported stream-start for backward compatibility.
1065 * FIXME 2.0: This should go away! */
1070 unlink_pads (const GValue * item, gpointer user_data)
1075 pad = g_value_get_object (item);
1077 if ((peer = gst_pad_get_peer (pad))) {
1078 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1079 gst_pad_unlink (pad, peer);
1081 gst_pad_unlink (peer, pad);
1082 gst_object_unref (peer);
1086 /* vmethod that adds an element to a bin
1091 gst_bin_add_func (GstBin * bin, GstElement * element)
1095 gboolean is_sink, is_source, provides_clock, requires_clock;
1096 GstMessage *clock_message = NULL, *async_message = NULL;
1097 GstStateChangeReturn ret;
1098 GList *l, *elem_contexts, *need_context_messages;
1100 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1102 /* we obviously can't add ourself to ourself */
1103 if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
1106 /* get the element name to make sure it is unique in this bin. */
1107 GST_OBJECT_LOCK (element);
1108 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1109 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1110 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1112 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1114 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1115 GST_OBJECT_UNLOCK (element);
1117 GST_OBJECT_LOCK (bin);
1119 /* then check to see if the element's name is already taken in the bin,
1120 * we can safely take the lock here. This check is probably bogus because
1121 * you can safely change the element name after this check and before setting
1122 * the object parent. The window is very small though... */
1123 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1124 goto duplicate_name;
1126 /* set the element's parent and add the element to the bin's list of children */
1127 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1128 GST_OBJECT_CAST (bin))))
1131 /* if we add a sink we become a sink */
1133 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1135 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1138 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1140 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1142 if (provides_clock) {
1143 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1145 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1146 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1148 if (requires_clock) {
1149 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1150 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1153 bin->children = g_list_prepend (bin->children, element);
1155 bin->children_cookie++;
1156 if (!GST_BIN_IS_NO_RESYNC (bin))
1157 bin->priv->structure_cookie++;
1159 /* distribute the bus */
1160 gst_element_set_bus (element, bin->child_bus);
1162 /* propagate the current base_time, start_time and clock */
1163 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1164 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1165 /* it's possible that the element did not accept the clock but
1166 * that is not important right now. When the pipeline goes to PLAYING,
1167 * a new clock will be selected */
1168 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1170 /* get the element's list of contexts before propagating our own */
1171 elem_contexts = gst_element_get_contexts (element);
1172 for (l = GST_ELEMENT_CAST (bin)->contexts; l; l = l->next)
1173 gst_element_set_context (element, l->data);
1175 need_context_messages = NULL;
1176 for (l = elem_contexts; l; l = l->next) {
1177 GstContext *replacement, *context = l->data;
1178 const gchar *context_type;
1180 context_type = gst_context_get_context_type (context);
1182 /* we already set this context above? */
1184 gst_element_get_context_unlocked (GST_ELEMENT (bin), context_type);
1186 gst_context_unref (replacement);
1191 /* ask our parent for the context */
1192 msg = gst_message_new_need_context (GST_OBJECT_CAST (bin), context_type);
1193 s = (GstStructure *) gst_message_get_structure (msg);
1194 gst_structure_set (s, "bin.old.context", GST_TYPE_CONTEXT, context, NULL);
1196 need_context_messages = g_list_prepend (need_context_messages, msg);
1201 /* set the cached index on the children */
1202 if (bin->priv->index)
1203 gst_element_set_index (element, bin->priv->index);
1206 ret = GST_STATE_RETURN (bin);
1207 /* no need to update the state if we are in error */
1208 if (ret == GST_STATE_CHANGE_FAILURE)
1209 goto no_state_recalc;
1211 /* update the bin state, the new element could have been an ASYNC or
1212 * NO_PREROLL element */
1213 ret = GST_STATE_RETURN (element);
1214 GST_DEBUG_OBJECT (bin, "added %s element",
1215 gst_element_state_change_return_get_name (ret));
1218 case GST_STATE_CHANGE_ASYNC:
1220 /* create message to track this aync element when it posts an async-done
1222 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1225 case GST_STATE_CHANGE_NO_PREROLL:
1226 /* ignore all async elements we might have and commit our state */
1227 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1229 case GST_STATE_CHANGE_FAILURE:
1236 GST_OBJECT_UNLOCK (bin);
1238 for (l = need_context_messages; l; l = l->next) {
1239 GstMessage *msg = l->data;
1241 const gchar *context_type;
1242 GstContext *replacement, *context;
1244 gst_message_parse_context_type (msg, &context_type);
1246 GST_LOG_OBJECT (bin, "asking parent for context type: %s "
1247 "from %" GST_PTR_FORMAT, context_type, element);
1249 s = (GstStructure *) gst_message_get_structure (msg);
1250 gst_structure_get (s, "bin.old.context", GST_TYPE_CONTEXT, &context, NULL);
1251 gst_structure_remove_field (s, "bin.old.context");
1252 gst_element_post_message (GST_ELEMENT_CAST (bin), msg);
1254 /* lock to avoid losing a potential write */
1255 GST_OBJECT_LOCK (bin);
1257 gst_element_get_context_unlocked (GST_ELEMENT_CAST (bin), context_type);
1260 /* we got the context set from GstElement::set_context */
1261 gst_context_unref (replacement);
1262 GST_OBJECT_UNLOCK (bin);
1264 /* Propagate the element's context upwards */
1265 GST_LOG_OBJECT (bin, "propagating existing context type: %s %p "
1266 "from %" GST_PTR_FORMAT, context_type, context, element);
1268 gst_bin_update_context_unlocked (bin, context);
1271 gst_message_new_have_context (GST_OBJECT_CAST (bin),
1272 gst_context_ref (context));
1273 GST_OBJECT_UNLOCK (bin);
1274 gst_element_post_message (GST_ELEMENT_CAST (bin), msg);
1276 gst_context_unref (context);
1278 g_list_free_full (elem_contexts, (GDestroyNotify) gst_context_unref);
1279 g_list_free (need_context_messages);
1281 /* post the messages on the bus of the element so that the bin can handle
1284 gst_element_post_message (element, clock_message);
1287 gst_element_post_message (element, async_message);
1289 /* unlink all linked pads */
1290 it = gst_element_iterate_pads (element);
1291 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1292 gst_iterator_free (it);
1294 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1297 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1298 gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
1305 /* ERROR handling here */
1308 GST_OBJECT_LOCK (bin);
1309 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1310 GST_OBJECT_UNLOCK (bin);
1315 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1316 elem_name, GST_ELEMENT_NAME (bin));
1317 GST_OBJECT_UNLOCK (bin);
1323 g_warning ("Element '%s' already has parent", elem_name);
1324 GST_OBJECT_UNLOCK (bin);
1333 * @element: (transfer full): the #GstElement to add
1335 * Adds the given element to the bin. Sets the element's parent, and thus
1336 * takes ownership of the element. An element can only be added to one bin.
1338 * If the element's pads are linked to other pads, the pads will be unlinked
1339 * before the element is added to the bin.
1342 * When you add an element to an already-running pipeline, you will have to
1343 * take care to set the state of the newly-added element to the desired
1344 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1345 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1346 * The bin or pipeline will not take care of this for you.
1351 * Returns: %TRUE if the element could be added, %FALSE if
1352 * the bin does not want to accept the element.
1355 gst_bin_add (GstBin * bin, GstElement * element)
1357 GstBinClass *bclass;
1360 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1361 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1362 g_return_val_if_fail (GST_ELEMENT_CAST (bin) != element, FALSE);
1364 bclass = GST_BIN_GET_CLASS (bin);
1366 if (G_UNLIKELY (bclass->add_element == NULL))
1369 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1370 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1371 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1373 GST_TRACER_BIN_ADD_PRE (bin, element);
1374 result = bclass->add_element (bin, element);
1375 GST_TRACER_BIN_ADD_POST (bin, element, result);
1379 /* ERROR handling */
1382 g_warning ("adding elements to bin '%s' is not supported",
1383 GST_ELEMENT_NAME (bin));
1388 /* remove an element from the bin
1393 gst_bin_remove_func (GstBin * bin, GstElement * element)
1397 gboolean is_sink, is_source, provides_clock, requires_clock;
1398 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1399 GstMessage *clock_message = NULL;
1400 GstClock **provided_clock_p;
1401 GstElement **clock_provider_p;
1403 gboolean other_async, this_async, have_no_preroll;
1404 GstStateChangeReturn ret;
1406 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1408 /* we obviously can't remove ourself from ourself */
1409 if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
1410 goto removing_itself;
1412 GST_OBJECT_LOCK (bin);
1414 GST_OBJECT_LOCK (element);
1415 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1417 if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
1420 /* remove the parent ref */
1421 GST_OBJECT_PARENT (element) = NULL;
1423 /* grab element name so we can print it */
1424 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1425 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1427 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1429 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1430 GST_OBJECT_UNLOCK (element);
1434 othersource = FALSE;
1435 otherprovider = FALSE;
1436 otherrequirer = FALSE;
1437 have_no_preroll = FALSE;
1438 /* iterate the elements, we collect which ones are async and no_preroll. We
1439 * also remove the element when we find it. */
1440 for (walk = bin->children; walk; walk = next) {
1441 GstElement *child = GST_ELEMENT_CAST (walk->data);
1443 next = g_list_next (walk);
1445 if (child == element) {
1447 /* remove the element */
1448 bin->children = g_list_delete_link (bin->children, walk);
1450 gboolean child_sink, child_source, child_provider, child_requirer;
1452 GST_OBJECT_LOCK (child);
1453 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1454 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1456 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1458 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1459 /* when we remove a sink, check if there are other sinks. */
1460 if (is_sink && !othersink && child_sink)
1462 if (is_source && !othersource && child_source)
1464 if (provides_clock && !otherprovider && child_provider)
1465 otherprovider = TRUE;
1466 if (requires_clock && !otherrequirer && child_requirer)
1467 otherrequirer = TRUE;
1468 /* check if we have NO_PREROLL children */
1469 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1470 have_no_preroll = TRUE;
1471 GST_OBJECT_UNLOCK (child);
1475 /* the element must have been in the bin's list of children */
1476 if (G_UNLIKELY (!found))
1479 /* we now removed the element from the list of elements, increment the cookie
1480 * so that others can detect a change in the children list. */
1482 bin->children_cookie++;
1483 if (!GST_BIN_IS_NO_RESYNC (bin))
1484 bin->priv->structure_cookie++;
1486 if (is_sink && !othersink) {
1487 /* we're not a sink anymore */
1488 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1489 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1491 if (is_source && !othersource) {
1492 /* we're not a source anymore */
1493 GST_DEBUG_OBJECT (bin, "we removed the last source");
1494 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1496 if (provides_clock && !otherprovider) {
1497 /* we're not a clock provider anymore */
1498 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1499 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1501 if (requires_clock && !otherrequirer) {
1502 /* we're not a clock requirer anymore */
1503 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1504 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1507 /* if the clock provider for this element is removed, we lost
1508 * the clock as well, we need to inform the parent of this
1509 * so that it can select a new clock */
1510 if (bin->clock_provider == element) {
1511 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1512 bin->clock_dirty = TRUE;
1514 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1515 provided_clock_p = &bin->provided_clock;
1516 clock_provider_p = &bin->clock_provider;
1517 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1518 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1521 /* remove messages for the element, if there was a pending ASYNC_START
1522 * message we must see if removing the element caused the bin to lose its
1525 other_async = FALSE;
1526 for (walk = bin->messages; walk; walk = next) {
1527 GstMessage *message = (GstMessage *) walk->data;
1528 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1531 next = g_list_next (walk);
1534 switch (GST_MESSAGE_TYPE (message)) {
1535 case GST_MESSAGE_ASYNC_START:
1541 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1543 case GST_MESSAGE_STRUCTURE_CHANGE:
1547 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1549 /* it's unlikely that this message is still in the list of messages
1550 * because this would mean that a link/unlink is busy in another thread
1551 * while we remove the element. We still have to remove the message
1552 * because we might not receive the done message anymore when the element
1553 * is removed from the bin. */
1554 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1555 if (owner == element)
1566 /* delete all message types */
1567 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1568 message, elem_name);
1569 bin->messages = g_list_delete_link (bin->messages, walk);
1570 gst_message_unref (message);
1574 /* get last return */
1575 ret = GST_STATE_RETURN (bin);
1577 /* no need to update the state if we are in error */
1578 if (ret == GST_STATE_CHANGE_FAILURE)
1579 goto no_state_recalc;
1581 if (!other_async && this_async) {
1582 /* all other elements were not async and we removed the async one,
1583 * handle the async-done case because we are not async anymore now. */
1584 GST_DEBUG_OBJECT (bin,
1585 "we removed the last async element, have no_preroll %d",
1588 /* the current state return of the bin depends on if there are no_preroll
1589 * elements in the pipeline or not */
1590 if (have_no_preroll)
1591 ret = GST_STATE_CHANGE_NO_PREROLL;
1593 ret = GST_STATE_CHANGE_SUCCESS;
1595 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1597 GST_DEBUG_OBJECT (bin,
1598 "recalc state preroll: %d, other async: %d, this async %d",
1599 have_no_preroll, other_async, this_async);
1601 if (have_no_preroll) {
1602 ret = GST_STATE_CHANGE_NO_PREROLL;
1603 } else if (other_async) {
1604 /* there are other async elements and we were not doing an async state
1605 * change, change our pending state and go async */
1606 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1607 GST_STATE_NEXT (bin) = GST_STATE (bin);
1608 GST_STATE_PENDING (bin) = GST_STATE (bin);
1610 ret = GST_STATE_CHANGE_ASYNC;
1612 GST_STATE_RETURN (bin) = ret;
1616 gst_element_set_bus (element, NULL);
1617 /* Clear the clock we provided to the element */
1618 gst_element_set_clock (element, NULL);
1619 GST_OBJECT_UNLOCK (bin);
1622 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1624 /* unlink all linked pads */
1625 it = gst_element_iterate_pads (element);
1626 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1627 gst_iterator_free (it);
1629 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1632 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1633 gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
1637 /* element is really out of our control now */
1638 gst_object_unref (element);
1642 /* ERROR handling */
1645 GST_OBJECT_LOCK (bin);
1646 g_warning ("Cannot remove bin '%s' from itself", GST_ELEMENT_NAME (bin));
1647 GST_OBJECT_UNLOCK (bin);
1652 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1653 GST_ELEMENT_NAME (bin));
1654 GST_OBJECT_UNLOCK (element);
1655 GST_OBJECT_UNLOCK (bin);
1664 * @element: (transfer none): the #GstElement to remove
1666 * Removes the element from the bin, unparenting it as well.
1667 * Unparenting the element means that the element will be dereferenced,
1668 * so if the bin holds the only reference to the element, the element
1669 * will be freed in the process of removing it from the bin. If you
1670 * want the element to still exist after removing, you need to call
1671 * gst_object_ref() before removing it from the bin.
1673 * If the element's pads are linked to other pads, the pads will be unlinked
1674 * before the element is removed from the bin.
1678 * Returns: %TRUE if the element could be removed, %FALSE if
1679 * the bin does not want to remove the element.
1682 gst_bin_remove (GstBin * bin, GstElement * element)
1684 GstBinClass *bclass;
1687 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1688 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1689 g_return_val_if_fail (GST_ELEMENT_CAST (bin) != element, FALSE);
1691 bclass = GST_BIN_GET_CLASS (bin);
1693 if (G_UNLIKELY (bclass->remove_element == NULL))
1696 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1697 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1699 GST_TRACER_BIN_REMOVE_PRE (bin, element);
1700 result = bclass->remove_element (bin, element);
1701 GST_TRACER_BIN_REMOVE_POST (bin, result);
1705 /* ERROR handling */
1708 g_warning ("removing elements from bin '%s' is not supported",
1709 GST_ELEMENT_NAME (bin));
1715 * gst_bin_iterate_elements:
1718 * Gets an iterator for the elements in this bin.
1720 * MT safe. Caller owns returned value.
1722 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1726 gst_bin_iterate_elements (GstBin * bin)
1728 GstIterator *result;
1730 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1732 GST_OBJECT_LOCK (bin);
1733 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1734 GST_OBJECT_GET_LOCK (bin),
1735 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1736 GST_OBJECT_UNLOCK (bin);
1741 static GstIteratorItem
1742 iterate_child_recurse (GstIterator * it, const GValue * item)
1744 GstElement *child = g_value_get_object (item);
1746 if (GST_IS_BIN (child)) {
1747 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1749 gst_iterator_push (it, other);
1751 return GST_ITERATOR_ITEM_PASS;
1755 * gst_bin_iterate_recurse:
1758 * Gets an iterator for the elements in this bin.
1759 * This iterator recurses into GstBin children.
1761 * MT safe. Caller owns returned value.
1763 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1767 gst_bin_iterate_recurse (GstBin * bin)
1769 GstIterator *result;
1771 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1773 GST_OBJECT_LOCK (bin);
1774 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1775 GST_OBJECT_GET_LOCK (bin),
1776 &bin->children_cookie,
1778 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1779 GST_OBJECT_UNLOCK (bin);
1784 /* returns 0 when TRUE because this is a GCompareFunc */
1787 bin_element_is_sink (GstElement * child, GstBin * bin)
1791 /* we lock the child here for the remainder of the function to
1792 * get its name and flag safely. */
1793 GST_OBJECT_LOCK (child);
1794 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1796 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1797 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1799 GST_OBJECT_UNLOCK (child);
1800 return is_sink ? 0 : 1;
1804 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1806 GstBin *bin = g_value_get_object (vbin);
1807 GstElement *child = g_value_get_object (vchild);
1809 return (bin_element_is_sink (child, bin));
1813 * gst_bin_iterate_sinks:
1816 * Gets an iterator for all elements in the bin that have the
1817 * #GST_ELEMENT_FLAG_SINK flag set.
1819 * MT safe. Caller owns returned value.
1821 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1825 gst_bin_iterate_sinks (GstBin * bin)
1827 GstIterator *children;
1828 GstIterator *result;
1829 GValue vbin = { 0, };
1831 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1833 g_value_init (&vbin, GST_TYPE_BIN);
1834 g_value_set_object (&vbin, bin);
1836 children = gst_bin_iterate_elements (bin);
1837 result = gst_iterator_filter (children,
1838 (GCompareFunc) sink_iterator_filter, &vbin);
1840 g_value_unset (&vbin);
1845 /* returns 0 when TRUE because this is a GCompareFunc */
1848 bin_element_is_src (GstElement * child, GstBin * bin)
1852 /* we lock the child here for the remainder of the function to
1853 * get its name and other info safely. */
1854 GST_OBJECT_LOCK (child);
1855 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1857 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1858 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1860 GST_OBJECT_UNLOCK (child);
1861 return is_src ? 0 : 1;
1865 src_iterator_filter (const GValue * vchild, GValue * vbin)
1867 GstBin *bin = g_value_get_object (vbin);
1868 GstElement *child = g_value_get_object (vchild);
1870 return (bin_element_is_src (child, bin));
1874 * gst_bin_iterate_sources:
1877 * Gets an iterator for all elements in the bin that have the
1878 * #GST_ELEMENT_FLAG_SOURCE flag set.
1880 * MT safe. Caller owns returned value.
1882 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
1886 gst_bin_iterate_sources (GstBin * bin)
1888 GstIterator *children;
1889 GstIterator *result;
1890 GValue vbin = { 0, };
1892 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1894 g_value_init (&vbin, GST_TYPE_BIN);
1895 g_value_set_object (&vbin, bin);
1897 children = gst_bin_iterate_elements (bin);
1898 result = gst_iterator_filter (children,
1899 (GCompareFunc) src_iterator_filter, &vbin);
1901 g_value_unset (&vbin);
1909 static GstStateChangeReturn
1910 gst_bin_get_state_func (GstElement * element, GstState * state,
1911 GstState * pending, GstClockTime timeout)
1913 GstStateChangeReturn ret;
1915 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1918 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1924 /***********************************************
1925 * Topologically sorted iterator
1926 * see http://en.wikipedia.org/wiki/Topological_sorting
1928 * For each element in the graph, an entry is kept in a HashTable
1929 * with its number of srcpad connections (degree).
1930 * We then change state of all elements without dependencies
1931 * (degree 0) and decrement the degree of all elements connected
1932 * on the sinkpads. When an element reaches degree 0, its state is
1934 * When all elements are handled the algorithm stops.
1936 typedef struct _GstBinSortIterator
1939 GQueue queue; /* elements queued for state change */
1940 GstBin *bin; /* bin we iterate */
1941 gint mode; /* adding or removing dependency */
1942 GstElement *best; /* next element with least dependencies */
1943 gint best_deg; /* best degree */
1944 GHashTable *hash; /* hashtable with element dependencies */
1945 gboolean dirty; /* we detected structure change */
1946 } GstBinSortIterator;
1949 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1950 GstBinSortIterator * copy)
1952 GHashTableIter iter;
1953 gpointer key, value;
1955 copy->queue = it->queue;
1956 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1958 copy->bin = gst_object_ref (it->bin);
1960 copy->best = gst_object_ref (it->best);
1962 copy->hash = g_hash_table_new (NULL, NULL);
1963 g_hash_table_iter_init (&iter, it->hash);
1964 while (g_hash_table_iter_next (&iter, &key, &value))
1965 g_hash_table_insert (copy->hash, key, value);
1968 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1969 #define HASH_SET_DEGREE(bit, elem, deg) \
1970 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1971 #define HASH_GET_DEGREE(bit, elem) \
1972 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1974 /* add element to queue of next elements in the iterator.
1975 * We push at the tail to give higher priority elements a
1978 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1980 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1981 GST_ELEMENT_NAME (element));
1982 gst_object_ref (element);
1983 g_queue_push_tail (&bit->queue, element);
1984 HASH_SET_DEGREE (bit, element, -1);
1988 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1992 if ((find = g_queue_find (&bit->queue, element))) {
1993 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1994 GST_ELEMENT_NAME (element));
1996 g_queue_delete_link (&bit->queue, find);
1997 gst_object_unref (element);
1999 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
2000 GST_ELEMENT_NAME (element));
2004 /* clear the queue, unref all objects as we took a ref when
2005 * we added them to the queue */
2007 clear_queue (GQueue * queue)
2011 while ((p = g_queue_pop_head (queue)))
2012 gst_object_unref (p);
2015 /* set all degrees to 0. Elements marked as a sink are
2016 * added to the queue immediately. Since we only look at the SINK flag of the
2017 * element, it is possible that we add non-sinks to the queue. These will be
2018 * removed from the queue again when we can prove that it provides data for some
2021 reset_degree (GstElement * element, GstBinSortIterator * bit)
2025 /* sinks are added right away */
2026 GST_OBJECT_LOCK (element);
2027 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
2028 GST_OBJECT_UNLOCK (element);
2031 add_to_queue (bit, element);
2033 /* others are marked with 0 and handled when sinks are done */
2034 HASH_SET_DEGREE (bit, element, 0);
2038 /* adjust the degree of all elements connected to the given
2039 * element. If a degree of an element drops to 0, it is
2040 * added to the queue of elements to schedule next.
2042 * We have to make sure not to cross the bin boundary this element
2046 update_degree (GstElement * element, GstBinSortIterator * bit)
2048 gboolean linked = FALSE;
2050 GST_OBJECT_LOCK (element);
2051 /* don't touch degree if element has no sinkpads */
2052 if (element->numsinkpads != 0) {
2053 /* loop over all sinkpads, decrement degree for all connected
2054 * elements in this bin */
2057 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
2060 pad = GST_PAD_CAST (pads->data);
2062 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
2063 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
2064 GST_MESSAGE_STRUCTURE_CHANGE))) {
2065 /* mark the iterator as dirty because we won't be updating the degree
2066 * of the peer parent now. This would result in the 'loop detected'
2067 * later on because the peer parent element could become the best next
2068 * element with a degree > 0. We will simply continue our state
2069 * changes and we'll eventually resync when the unlink completed and
2070 * the iterator cookie is updated. */
2075 if ((peer = gst_pad_get_peer (pad))) {
2076 GstElement *peer_element;
2078 if ((peer_element = gst_pad_get_parent_element (peer))) {
2079 GST_OBJECT_LOCK (peer_element);
2080 /* check that we don't go outside of this bin */
2081 if (GST_OBJECT_CAST (peer_element)->parent ==
2082 GST_OBJECT_CAST (bit->bin)) {
2083 gint old_deg, new_deg;
2085 old_deg = HASH_GET_DEGREE (bit, peer_element);
2087 /* check to see if we added an element as sink that was not really a
2088 * sink because it was connected to some other element. */
2089 if (old_deg == -1) {
2090 remove_from_queue (bit, peer_element);
2093 new_deg = old_deg + bit->mode;
2095 GST_DEBUG_OBJECT (bit->bin,
2096 "change element %s, degree %d->%d, linked to %s",
2097 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
2098 GST_ELEMENT_NAME (element));
2100 /* update degree, it is possible that an element was in 0 and
2101 * reaches -1 here. This would mean that the element had no sinkpads
2102 * but became linked while the state change was happening. We will
2103 * resync on this with the structure change message. */
2105 /* degree hit 0, add to queue */
2106 add_to_queue (bit, peer_element);
2108 HASH_SET_DEGREE (bit, peer_element, new_deg);
2112 GST_OBJECT_UNLOCK (peer_element);
2113 gst_object_unref (peer_element);
2115 gst_object_unref (peer);
2120 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
2121 GST_ELEMENT_NAME (element));
2123 GST_OBJECT_UNLOCK (element);
2126 /* find the next best element not handled yet. This is the one
2127 * with the lowest non-negative degree */
2129 find_element (GstElement * element, GstBinSortIterator * bit)
2133 /* element is already handled */
2134 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
2137 /* first element or element with smaller degree */
2138 if (bit->best == NULL || bit->best_deg > degree) {
2139 bit->best = element;
2140 bit->best_deg = degree;
2144 /* get next element in iterator. */
2145 static GstIteratorResult
2146 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2149 GstBin *bin = bit->bin;
2151 /* empty queue, we have to find a next best element */
2152 if (g_queue_is_empty (&bit->queue)) {
2154 bit->best_deg = G_MAXINT;
2155 g_list_foreach (bin->children, (GFunc) find_element, bit);
2156 if ((best = bit->best)) {
2157 /* when we detected an unlink, don't warn because our degrees might be
2158 * screwed up. We will resync later */
2159 if (bit->best_deg != 0 && !bit->dirty) {
2160 /* we don't fail on this one yet */
2161 GST_WARNING_OBJECT (bin, "loop dected in graph");
2162 g_warning ("loop detected in the graph of bin '%s'!!",
2163 GST_ELEMENT_NAME (bin));
2165 /* best unhandled element, schedule as next element */
2166 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2167 GST_ELEMENT_NAME (best));
2168 HASH_SET_DEGREE (bit, best, -1);
2169 g_value_set_object (result, best);
2171 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2172 /* no more unhandled elements, we are done */
2173 return GST_ITERATOR_DONE;
2176 /* everything added to the queue got reffed */
2177 best = g_queue_pop_head (&bit->queue);
2178 g_value_set_object (result, best);
2179 gst_object_unref (best);
2182 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2183 /* update degrees of linked elements */
2184 update_degree (best, bit);
2186 return GST_ITERATOR_OK;
2189 /* clear queues, recalculate the degrees and restart. */
2191 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2193 GstBin *bin = bit->bin;
2195 GST_DEBUG_OBJECT (bin, "resync");
2197 clear_queue (&bit->queue);
2199 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2200 /* calc degrees, incrementing */
2202 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2203 /* for the rest of the function we decrement the degrees */
2207 /* clear queues, unref bin and free iterator. */
2209 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2211 GstBin *bin = bit->bin;
2213 GST_DEBUG_OBJECT (bin, "free");
2214 clear_queue (&bit->queue);
2215 g_hash_table_destroy (bit->hash);
2216 gst_object_unref (bin);
2219 /* should be called with the bin LOCK held */
2220 static GstIterator *
2221 gst_bin_sort_iterator_new (GstBin * bin)
2223 GstBinSortIterator *result;
2225 /* we don't need an ItemFunction because we ref the items in the _next
2227 result = (GstBinSortIterator *)
2228 gst_iterator_new (sizeof (GstBinSortIterator),
2230 GST_OBJECT_GET_LOCK (bin),
2231 &bin->priv->structure_cookie,
2232 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2233 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2234 (GstIteratorItemFunction) NULL,
2235 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2236 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2237 g_queue_init (&result->queue);
2238 result->hash = g_hash_table_new (NULL, NULL);
2239 gst_object_ref (bin);
2241 gst_bin_sort_iterator_resync (result);
2243 return (GstIterator *) result;
2247 * gst_bin_iterate_sorted:
2250 * Gets an iterator for the elements in this bin in topologically
2251 * sorted order. This means that the elements are returned from
2252 * the most downstream elements (sinks) to the sources.
2254 * This function is used internally to perform the state changes
2255 * of the bin elements and for clock selection.
2257 * MT safe. Caller owns returned value.
2259 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement,
2263 gst_bin_iterate_sorted (GstBin * bin)
2265 GstIterator *result;
2267 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2269 GST_OBJECT_LOCK (bin);
2270 result = gst_bin_sort_iterator_new (bin);
2271 GST_OBJECT_UNLOCK (bin);
2276 static GstStateChangeReturn
2277 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2278 GstClockTime base_time, GstClockTime start_time, GstState current,
2281 GstStateChangeReturn ret;
2282 GstState child_current, child_pending;
2286 GST_STATE_LOCK (element);
2288 GST_OBJECT_LOCK (element);
2289 /* set base_time and start time on child */
2290 GST_ELEMENT_START_TIME (element) = start_time;
2291 element->base_time = base_time;
2292 /* peel off the locked flag */
2293 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2294 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2295 ret = GST_STATE_RETURN (element);
2296 child_current = GST_STATE (element);
2297 child_pending = GST_STATE_PENDING (element);
2298 GST_OBJECT_UNLOCK (element);
2300 /* skip locked elements */
2301 if (G_UNLIKELY (locked))
2304 /* if the element was no preroll, just start changing the state regardless
2305 * if it had async elements (in the case of a bin) because they won't preroll
2307 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2308 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2312 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2313 "current %s pending %s, desired next %s",
2314 gst_element_state_get_name (child_current),
2315 gst_element_state_get_name (child_pending),
2316 gst_element_state_get_name (next));
2318 /* always recurse into bins so that we can set the base time */
2319 if (GST_IS_BIN (element))
2322 /* Try not to change the state of elements that are already in the state we're
2324 if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
2325 /* child is already at the requested state, return previous return. Note that
2326 * if the child has a pending state to next, we will still call the
2327 * set_state function */
2329 } else if (next > current) {
2330 /* upward state change */
2331 if (child_pending == GST_STATE_VOID_PENDING) {
2332 /* .. and the child is not busy doing anything */
2333 if (child_current > next) {
2334 /* .. and is already past the requested state, assume it got there
2336 ret = GST_STATE_CHANGE_SUCCESS;
2339 } else if (child_pending > child_current) {
2340 /* .. and the child is busy going upwards */
2341 if (child_current >= next) {
2342 /* .. and is already past the requested state, assume it got there
2344 ret = GST_STATE_CHANGE_SUCCESS;
2348 /* .. and the child is busy going downwards */
2349 if (child_current > next) {
2350 /* .. and is already past the requested state, assume it got there
2352 ret = GST_STATE_CHANGE_SUCCESS;
2356 } else if (next < current) {
2357 /* downward state change */
2358 if (child_pending == GST_STATE_VOID_PENDING) {
2359 /* .. and the child is not busy doing anything */
2360 if (child_current < next) {
2361 /* .. and is already past the requested state, assume it got there
2363 ret = GST_STATE_CHANGE_SUCCESS;
2366 } else if (child_pending < child_current) {
2367 /* .. and the child is busy going downwards */
2368 if (child_current <= next) {
2369 /* .. and is already past the requested state, assume it got there
2371 ret = GST_STATE_CHANGE_SUCCESS;
2375 /* .. and the child is busy going upwards */
2376 if (child_current < next) {
2377 /* .. and is already past the requested state, assume it got there
2379 ret = GST_STATE_CHANGE_SUCCESS;
2386 GST_OBJECT_LOCK (bin);
2387 /* the element was busy with an upwards async state change, we must wait for
2388 * an ASYNC_DONE message before we attemp to change the state. */
2390 find_message (bin, GST_OBJECT_CAST (element),
2391 GST_MESSAGE_ASYNC_START))) {
2392 #ifndef GST_DISABLE_GST_DEBUG
2393 GstMessage *message = GST_MESSAGE_CAST (found->data);
2395 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2396 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2398 /* only wait for upward state changes */
2399 if (next > current) {
2400 /* We found an async element check if we can force its state to change or
2401 * if we have to wait for it to preroll. */
2405 GST_OBJECT_UNLOCK (bin);
2408 GST_DEBUG_OBJECT (bin,
2409 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2410 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2411 GST_TIME_ARGS (base_time));
2414 ret = gst_element_set_state (element, next);
2416 GST_STATE_UNLOCK (element);
2422 GST_DEBUG_OBJECT (element,
2423 "element is locked, return previous return %s",
2424 gst_element_state_change_return_get_name (ret));
2425 GST_STATE_UNLOCK (element);
2430 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2431 "skipping transition from %s to %s",
2432 gst_element_state_get_name (child_current),
2433 gst_element_state_get_name (next));
2434 GST_STATE_UNLOCK (element);
2439 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2440 GST_OBJECT_UNLOCK (bin);
2441 GST_STATE_UNLOCK (element);
2442 return GST_STATE_CHANGE_ASYNC;
2446 /* gst_iterator_fold functions for pads_activate
2447 * Stop the iterator if activating one pad failed, but only if that pad
2448 * has not been removed from the element. */
2450 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2452 GstPad *pad = g_value_get_object (vpad);
2453 gboolean cont = TRUE;
2455 if (!gst_pad_set_active (pad, *active)) {
2456 if (GST_PAD_PARENT (pad) != NULL) {
2458 g_value_set_boolean (ret, FALSE);
2465 /* returns false on error or early cutout of the fold, true if all
2466 * pads in @iter were (de)activated successfully. */
2468 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2470 GstIteratorResult ires;
2473 /* no need to unset this later, it's just a boolean */
2474 g_value_init (&ret, G_TYPE_BOOLEAN);
2475 g_value_set_boolean (&ret, TRUE);
2478 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2481 case GST_ITERATOR_RESYNC:
2482 /* need to reset the result again */
2483 g_value_set_boolean (&ret, TRUE);
2484 gst_iterator_resync (iter);
2486 case GST_ITERATOR_DONE:
2487 /* all pads iterated, return collected value */
2490 /* iterator returned _ERROR or premature end with _OK,
2491 * mark an error and exit */
2492 g_value_set_boolean (&ret, FALSE);
2497 /* return collected value */
2498 return g_value_get_boolean (&ret);
2501 /* is called with STATE_LOCK
2504 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2509 GST_DEBUG_OBJECT (bin, "%s pads", active ? "activate" : "deactivate");
2511 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2512 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2513 gst_iterator_free (iter);
2514 if (G_UNLIKELY (!fold_ok))
2517 GST_DEBUG_OBJECT (bin, "pad %sactivation successful", active ? "" : "de");
2524 GST_DEBUG_OBJECT (bin, "pad %sactivation failed", active ? "" : "de");
2530 * gst_bin_recalculate_latency:
2533 * Query @bin for the current latency using and reconfigures this latency to all the
2534 * elements with a LATENCY event.
2536 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2537 * is posted on the bus.
2539 * This function simply emits the 'do-latency' signal so any custom latency
2540 * calculations will be performed.
2542 * Returns: %TRUE if the latency could be queried and reconfigured.
2545 gst_bin_recalculate_latency (GstBin * bin)
2549 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2550 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2556 gst_bin_do_latency_func (GstBin * bin)
2559 GstElement *element;
2560 GstClockTime min_latency, max_latency;
2563 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2565 element = GST_ELEMENT_CAST (bin);
2567 GST_DEBUG_OBJECT (element, "querying latency");
2569 query = gst_query_new_latency ();
2570 if ((res = gst_element_query (element, query))) {
2573 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2575 GST_DEBUG_OBJECT (element,
2576 "got min latency %" GST_TIME_FORMAT ", max latency %"
2577 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2578 GST_TIME_ARGS (max_latency), live);
2580 if (max_latency < min_latency) {
2581 /* this is an impossible situation, some parts of the pipeline might not
2582 * work correctly. We post a warning for now. */
2583 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2584 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2585 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2586 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2589 /* configure latency on elements */
2590 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2592 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2593 GST_TIME_ARGS (min_latency));
2595 GST_WARNING_OBJECT (element,
2596 "did not really configure latency of %" GST_TIME_FORMAT,
2597 GST_TIME_ARGS (min_latency));
2600 /* this is not a real problem, we just don't configure any latency. */
2601 GST_WARNING_OBJECT (element, "failed to query latency");
2603 gst_query_unref (query);
2609 gst_bin_post_message (GstElement * element, GstMessage * msg)
2611 GstElementClass *pklass = (GstElementClass *) parent_class;
2614 ret = pklass->post_message (element, gst_message_ref (msg));
2616 if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_STATE_CHANGED &&
2617 GST_MESSAGE_SRC (msg) == GST_OBJECT_CAST (element)) {
2618 GstState newstate, pending;
2620 gst_message_parse_state_changed (msg, NULL, &newstate, &pending);
2621 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING) {
2622 GST_BIN_CAST (element)->priv->posted_playing = TRUE;
2623 bin_do_eos (GST_BIN_CAST (element));
2625 GST_BIN_CAST (element)->priv->posted_playing = FALSE;
2629 gst_message_unref (msg);
2635 reset_state (const GValue * data, gpointer user_data)
2637 GstElement *e = g_value_get_object (data);
2638 GstState state = GPOINTER_TO_INT (user_data);
2640 if (gst_element_set_state (e, state) == GST_STATE_CHANGE_FAILURE)
2641 GST_WARNING_OBJECT (e, "Failed to switch back down to %s",
2642 gst_element_state_get_name (state));
2645 static GstStateChangeReturn
2646 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2649 GstStateChangeReturn ret;
2650 GstState current, next;
2651 gboolean have_async;
2652 gboolean have_no_preroll;
2653 GstClockTime base_time, start_time;
2656 GValue data = { 0, };
2658 /* we don't need to take the STATE_LOCK, it is already taken */
2659 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2660 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2662 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2663 "changing state of children from %s to %s",
2664 gst_element_state_get_name (current), gst_element_state_get_name (next));
2666 bin = GST_BIN_CAST (element);
2669 case GST_STATE_PLAYING:
2673 GST_OBJECT_LOCK (bin);
2674 toplevel = BIN_IS_TOPLEVEL (bin);
2675 GST_OBJECT_UNLOCK (bin);
2678 gst_bin_recalculate_latency (bin);
2681 case GST_STATE_PAUSED:
2682 /* Clear EOS list on next PAUSED */
2683 GST_OBJECT_LOCK (bin);
2684 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2685 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2686 bin->priv->posted_eos = FALSE;
2687 if (current == GST_STATE_READY)
2688 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
2689 GST_OBJECT_UNLOCK (bin);
2690 if (current == GST_STATE_READY)
2691 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2692 goto activate_failure;
2694 case GST_STATE_READY:
2695 /* Clear message list on next READY */
2696 GST_OBJECT_LOCK (bin);
2697 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2698 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2699 GST_OBJECT_UNLOCK (bin);
2700 /* We might not have reached PAUSED yet due to async errors,
2701 * make sure to always deactivate the pads nonetheless */
2702 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2703 goto activate_failure;
2705 case GST_STATE_NULL:
2706 if (current == GST_STATE_READY) {
2707 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2708 goto activate_failure;
2715 /* this flag is used to make the async state changes return immediately. We
2716 * don't want them to interfere with this state change */
2717 GST_OBJECT_LOCK (bin);
2718 bin->polling = TRUE;
2719 GST_OBJECT_UNLOCK (bin);
2721 /* iterate in state change order */
2722 it = gst_bin_iterate_sorted (bin);
2724 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2725 * Note how we don't reset this value when a resync happens, the reason being
2726 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2727 * even after a resync when the async element is gone */
2731 /* take base_time */
2732 base_time = gst_element_get_base_time (element);
2733 start_time = gst_element_get_start_time (element);
2735 have_no_preroll = FALSE;
2739 switch (gst_iterator_next (it, &data)) {
2740 case GST_ITERATOR_OK:
2744 child = g_value_get_object (&data);
2746 /* set state and base_time now */
2747 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2751 case GST_STATE_CHANGE_SUCCESS:
2752 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2753 "child '%s' changed state to %d(%s) successfully",
2754 GST_ELEMENT_NAME (child), next,
2755 gst_element_state_get_name (next));
2757 case GST_STATE_CHANGE_ASYNC:
2759 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2760 "child '%s' is changing state asynchronously to %s",
2761 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2765 case GST_STATE_CHANGE_FAILURE:{
2768 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2769 "child '%s' failed to go to state %d(%s)",
2770 GST_ELEMENT_NAME (child),
2771 next, gst_element_state_get_name (next));
2773 /* Only fail if the child is still inside
2774 * this bin. It might've been removed already
2775 * because of the error by the bin subclass
2776 * to ignore the error. */
2777 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2778 if (parent == GST_OBJECT_CAST (element)) {
2779 /* element is still in bin, really error now */
2780 gst_object_unref (parent);
2783 /* child removed from bin, let the resync code redo the state
2785 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2786 "child '%s' was removed from the bin",
2787 GST_ELEMENT_NAME (child));
2790 gst_object_unref (parent);
2794 case GST_STATE_CHANGE_NO_PREROLL:
2795 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2796 "child '%s' changed state to %d(%s) successfully without preroll",
2797 GST_ELEMENT_NAME (child), next,
2798 gst_element_state_get_name (next));
2799 have_no_preroll = TRUE;
2802 g_assert_not_reached ();
2805 g_value_reset (&data);
2808 case GST_ITERATOR_RESYNC:
2809 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2810 gst_iterator_resync (it);
2813 case GST_ITERATOR_DONE:
2814 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2820 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2821 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2824 if (have_no_preroll) {
2825 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2826 "we have NO_PREROLL elements %s -> NO_PREROLL",
2827 gst_element_state_change_return_get_name (ret));
2828 ret = GST_STATE_CHANGE_NO_PREROLL;
2829 } else if (have_async) {
2830 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2831 "we have ASYNC elements %s -> ASYNC",
2832 gst_element_state_change_return_get_name (ret));
2833 ret = GST_STATE_CHANGE_ASYNC;
2837 g_value_unset (&data);
2838 gst_iterator_free (it);
2840 GST_OBJECT_LOCK (bin);
2841 bin->polling = FALSE;
2842 /* it's possible that we did not get ASYNC from the children while the bin is
2843 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2844 * itself as the source. In that case we still want to check if the state
2845 * change completed. */
2846 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2847 /* no element returned ASYNC and there are no pending async_done messages,
2848 * we can just complete. */
2849 GST_DEBUG_OBJECT (bin, "no async elements");
2852 /* when we get here an ASYNC element was found */
2853 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2854 /* we ignore ASYNC state changes when we go to READY or NULL */
2855 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2856 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2860 GST_DEBUG_OBJECT (bin, "check async elements");
2861 /* check if all elements managed to commit their state already */
2862 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2863 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2864 * all the elements commited their state while we were doing the state
2865 * change. We will still return ASYNC for consistency but we commit the
2866 * state already so that a _get_state() will return immediately. */
2867 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2869 GST_DEBUG_OBJECT (bin, "async elements commited");
2870 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
2871 GST_CLOCK_TIME_NONE);
2875 bin->priv->pending_async_done = FALSE;
2876 GST_OBJECT_UNLOCK (bin);
2878 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2879 "done changing bin's state from %s to %s, now in %s, ret %s",
2880 gst_element_state_get_name (current),
2881 gst_element_state_get_name (next),
2882 gst_element_state_get_name (GST_STATE (element)),
2883 gst_element_state_change_return_get_name (ret));
2890 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2891 "failure (de)activating src pads");
2892 return GST_STATE_CHANGE_FAILURE;
2897 if (current < next) {
2898 GstIterator *it = gst_bin_iterate_sorted (GST_BIN (element));
2899 GstIteratorResult ret;
2901 GST_DEBUG_OBJECT (element,
2902 "Bin failed to change state, switching children back to %s",
2903 gst_element_state_get_name (current));
2906 gst_iterator_foreach (it, &reset_state, GINT_TO_POINTER (current));
2907 } while (ret == GST_ITERATOR_RESYNC);
2908 gst_iterator_free (it);
2915 * This function is a utility event handler for seek events.
2916 * It will send the event to all sinks or sources and appropriate
2917 * ghost pads depending on the event-direction.
2919 * Applications are free to override this behaviour and
2920 * implement their own seek handler, but this will work for
2921 * pretty much all cases in practice.
2924 gst_bin_send_event (GstElement * element, GstEvent * event)
2926 GstBin *bin = GST_BIN_CAST (element);
2928 gboolean res = TRUE;
2929 gboolean done = FALSE;
2930 GValue data = { 0, };
2932 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2933 iter = gst_bin_iterate_sources (bin);
2934 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2935 GST_EVENT_TYPE_NAME (event));
2937 iter = gst_bin_iterate_sinks (bin);
2938 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2939 GST_EVENT_TYPE_NAME (event));
2943 switch (gst_iterator_next (iter, &data)) {
2944 case GST_ITERATOR_OK:
2946 GstElement *child = g_value_get_object (&data);
2948 gst_event_ref (event);
2949 res &= gst_element_send_event (child, event);
2951 GST_LOG_OBJECT (child, "After handling %s event: %d",
2952 GST_EVENT_TYPE_NAME (event), res);
2954 g_value_reset (&data);
2957 case GST_ITERATOR_RESYNC:
2958 gst_iterator_resync (iter);
2961 case GST_ITERATOR_DONE:
2964 case GST_ITERATOR_ERROR:
2965 g_assert_not_reached ();
2969 g_value_unset (&data);
2970 gst_iterator_free (iter);
2972 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2973 iter = gst_element_iterate_sink_pads (GST_ELEMENT (bin));
2974 GST_DEBUG_OBJECT (bin, "Sending %s event to sink pads",
2975 GST_EVENT_TYPE_NAME (event));
2977 iter = gst_element_iterate_src_pads (GST_ELEMENT (bin));
2978 GST_DEBUG_OBJECT (bin, "Sending %s event to src pads",
2979 GST_EVENT_TYPE_NAME (event));
2984 switch (gst_iterator_next (iter, &data)) {
2985 case GST_ITERATOR_OK:
2987 GstPad *pad = g_value_get_object (&data);
2989 gst_event_ref (event);
2990 res &= gst_pad_send_event (pad, event);
2991 GST_LOG_OBJECT (pad, "After handling %s event: %d",
2992 GST_EVENT_TYPE_NAME (event), res);
2995 case GST_ITERATOR_RESYNC:
2996 gst_iterator_resync (iter);
2999 case GST_ITERATOR_DONE:
3002 case GST_ITERATOR_ERROR:
3003 g_assert_not_reached ();
3008 g_value_unset (&data);
3009 gst_iterator_free (iter);
3010 gst_event_unref (event);
3015 /* this is the function called by the threadpool. When async elements commit
3016 * their state, this function will attempt to bring the bin to the next state.
3019 gst_bin_continue_func (BinContinueData * data)
3022 GstState current, next, pending;
3023 GstStateChange transition;
3026 pending = data->pending;
3028 GST_DEBUG_OBJECT (bin, "waiting for state lock");
3029 GST_STATE_LOCK (bin);
3031 GST_DEBUG_OBJECT (bin, "doing state continue");
3032 GST_OBJECT_LOCK (bin);
3034 /* if a new state change happened after this thread was scheduled, we return
3036 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
3039 current = GST_STATE (bin);
3040 next = GST_STATE_GET_NEXT (current, pending);
3041 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
3043 GST_STATE_NEXT (bin) = next;
3044 GST_STATE_PENDING (bin) = pending;
3046 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3047 GST_OBJECT_UNLOCK (bin);
3049 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3050 "continue state change %s to %s, final %s",
3051 gst_element_state_get_name (current),
3052 gst_element_state_get_name (next), gst_element_state_get_name (pending));
3054 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
3056 GST_STATE_UNLOCK (bin);
3057 GST_DEBUG_OBJECT (bin, "state continue done");
3059 gst_object_unref (bin);
3060 g_slice_free (BinContinueData, data);
3065 GST_OBJECT_UNLOCK (bin);
3066 GST_STATE_UNLOCK (bin);
3067 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
3068 gst_object_unref (bin);
3069 g_slice_free (BinContinueData, data);
3074 static GstBusSyncReply
3075 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
3077 GstBinClass *bclass;
3079 bclass = GST_BIN_GET_CLASS (bin);
3080 if (bclass->handle_message)
3081 bclass->handle_message (bin, message);
3083 gst_message_unref (message);
3085 return GST_BUS_DROP;
3089 bin_push_state_continue (BinContinueData * data)
3096 klass = GST_BIN_GET_CLASS (bin);
3098 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
3099 g_thread_pool_push (klass->pool, data, NULL);
3102 /* an element started an async state change, if we were not busy with a state
3103 * change, we perform a lost state.
3104 * This function is called with the OBJECT lock.
3107 bin_handle_async_start (GstBin * bin)
3109 GstState old_state, new_state;
3111 GstMessage *amessage = NULL;
3113 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3116 /* get our toplevel state */
3117 toplevel = BIN_IS_TOPLEVEL (bin);
3119 /* prepare an ASYNC_START message, we always post the start message even if we
3120 * are busy with a state change or when we are NO_PREROLL. */
3122 /* non toplevel bin, prepare async-start for the parent */
3123 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
3125 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
3128 /* async starts are ignored when we are NO_PREROLL */
3129 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
3130 goto was_no_preroll;
3132 old_state = GST_STATE (bin);
3134 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
3135 * PLAYING after optionally redistributing the base_time. */
3136 if (old_state > GST_STATE_PAUSED)
3137 new_state = GST_STATE_PAUSED;
3139 new_state = old_state;
3141 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
3142 "lost state of %s, new %s", gst_element_state_get_name (old_state),
3143 gst_element_state_get_name (new_state));
3145 GST_STATE (bin) = new_state;
3146 GST_STATE_NEXT (bin) = new_state;
3147 GST_STATE_PENDING (bin) = new_state;
3148 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3149 GST_OBJECT_UNLOCK (bin);
3152 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
3157 /* post our ASYNC_START. */
3158 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
3159 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3161 GST_OBJECT_LOCK (bin);
3167 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3172 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3173 GST_OBJECT_UNLOCK (bin);
3178 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
3179 GST_OBJECT_UNLOCK (bin);
3184 /* this function is called when there are no more async elements in the bin. We
3185 * post a state changed message and an ASYNC_DONE message.
3186 * This function is called with the OBJECT lock.
3189 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
3190 gboolean flag_pending, GstClockTime running_time)
3192 GstState current, pending, target;
3193 GstStateChangeReturn old_ret;
3194 GstState old_state, old_next;
3195 gboolean toplevel, state_changed = FALSE;
3196 GstMessage *amessage = NULL;
3197 BinContinueData *cont = NULL;
3199 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3202 pending = GST_STATE_PENDING (bin);
3207 /* check if there is something to commit */
3208 if (pending == GST_STATE_VOID_PENDING)
3209 goto nothing_pending;
3211 old_ret = GST_STATE_RETURN (bin);
3212 GST_STATE_RETURN (bin) = ret;
3214 /* move to the next target state */
3215 target = GST_STATE_TARGET (bin);
3216 pending = GST_STATE_PENDING (bin) = target;
3218 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
3220 old_state = GST_STATE (bin);
3221 /* this is the state we should go to next */
3222 old_next = GST_STATE_NEXT (bin);
3224 if (old_next != GST_STATE_PLAYING) {
3225 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3226 "committing state from %s to %s, old pending %s",
3227 gst_element_state_get_name (old_state),
3228 gst_element_state_get_name (old_next),
3229 gst_element_state_get_name (pending));
3231 /* update current state */
3232 current = GST_STATE (bin) = old_next;
3234 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3235 "setting state from %s to %s, pending %s",
3236 gst_element_state_get_name (old_state),
3237 gst_element_state_get_name (old_state),
3238 gst_element_state_get_name (pending));
3239 current = old_state;
3242 /* get our toplevel state */
3243 toplevel = BIN_IS_TOPLEVEL (bin);
3245 /* see if we reached the final state. If we are not toplevel, we also have to
3246 * stop here, the parent will continue our state. */
3247 if ((pending == current) || !toplevel) {
3248 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3249 "completed state change, pending VOID");
3251 /* mark VOID pending */
3252 pending = GST_STATE_VOID_PENDING;
3253 GST_STATE_PENDING (bin) = pending;
3254 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
3256 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3257 "continue state change, pending %s",
3258 gst_element_state_get_name (pending));
3260 cont = g_slice_new (BinContinueData);
3262 /* ref to the bin */
3263 cont->bin = gst_object_ref (bin);
3264 /* cookie to detect concurrent state change */
3265 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3266 /* pending target state */
3267 cont->pending = pending;
3269 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3270 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3273 if (old_next != GST_STATE_PLAYING) {
3274 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3275 state_changed = TRUE;
3278 GST_OBJECT_UNLOCK (bin);
3280 if (state_changed) {
3281 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3285 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3286 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3287 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3290 GST_OBJECT_LOCK (bin);
3292 /* toplevel, start continue state */
3293 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3294 bin_push_state_continue (cont);
3296 GST_DEBUG_OBJECT (bin, "state change complete");
3297 GST_STATE_BROADCAST (bin);
3303 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3308 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3309 /* if we were busy with a state change and we are requested to flag a
3310 * pending async done, we do so here */
3312 bin->priv->pending_async_done = TRUE;
3317 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3323 bin_do_eos (GstBin * bin)
3328 GST_OBJECT_LOCK (bin);
3329 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3330 * we forward the EOS message to the parent bin or application
3332 eos = GST_STATE (bin) == GST_STATE_PLAYING
3333 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3334 && bin->priv->posted_playing && is_eos (bin, &seqnum);
3335 GST_OBJECT_UNLOCK (bin);
3338 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3340 GstMessage *tmessage;
3342 /* Clear out any further messages, and reset posted_eos so we can
3343 detect any new EOS that happens (eg, after a seek). Since all
3344 sinks have now posted an EOS, there will be no further EOS events
3345 seen unless there is a new logical EOS */
3346 GST_OBJECT_LOCK (bin);
3347 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3348 bin->priv->posted_eos = FALSE;
3349 GST_OBJECT_UNLOCK (bin);
3351 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3352 gst_message_set_seqnum (tmessage, seqnum);
3353 GST_DEBUG_OBJECT (bin,
3354 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3355 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3360 bin_do_stream_start (GstBin * bin)
3363 gboolean stream_start;
3364 gboolean have_group_id = FALSE;
3367 GST_OBJECT_LOCK (bin);
3368 /* If all sinks are STREAM_START we forward the STREAM_START message
3369 * to the parent bin or application
3371 stream_start = is_stream_start (bin, &seqnum, &have_group_id, &group_id);
3372 GST_OBJECT_UNLOCK (bin);
3375 GstMessage *tmessage;
3377 GST_OBJECT_LOCK (bin);
3378 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
3379 GST_OBJECT_UNLOCK (bin);
3381 tmessage = gst_message_new_stream_start (GST_OBJECT_CAST (bin));
3382 gst_message_set_seqnum (tmessage, seqnum);
3384 gst_message_set_group_id (tmessage, group_id);
3386 GST_DEBUG_OBJECT (bin,
3387 "all sinks posted STREAM_START, posting seqnum #%" G_GUINT32_FORMAT,
3389 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3393 /* must be called without the object lock as it posts messages */
3395 bin_do_message_forward (GstBin * bin, GstMessage * message)
3397 if (bin->priv->message_forward) {
3398 GstMessage *forwarded;
3400 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3401 GST_MESSAGE_TYPE_NAME (message));
3403 /* we need to convert these messages to element messages so that our parent
3404 * bin can easily ignore them and so that the application can easily
3405 * distinguish between the internally forwarded and the real messages. */
3406 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3407 gst_structure_new ("GstBinForwarded",
3408 "message", GST_TYPE_MESSAGE, message, NULL));
3410 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3415 gst_bin_update_context (GstBin * bin, GstContext * context)
3417 GST_OBJECT_LOCK (bin);
3418 gst_bin_update_context_unlocked (bin, context);
3419 GST_OBJECT_UNLOCK (bin);
3423 gst_bin_update_context_unlocked (GstBin * bin, GstContext * context)
3425 const gchar *context_type;
3426 GList *l, **contexts;
3428 contexts = &GST_ELEMENT_CAST (bin)->contexts;
3429 context_type = gst_context_get_context_type (context);
3431 GST_DEBUG_OBJECT (bin, "set context %p %" GST_PTR_FORMAT, context,
3432 gst_context_get_structure (context));
3433 for (l = *contexts; l; l = l->next) {
3434 GstContext *tmp = l->data;
3435 const gchar *tmp_type = gst_context_get_context_type (tmp);
3437 /* Always store newest context but never replace
3438 * a persistent one by a non-persistent one */
3439 if (strcmp (context_type, tmp_type) == 0 &&
3440 (gst_context_is_persistent (context) ||
3441 !gst_context_is_persistent (tmp))) {
3442 gst_context_replace ((GstContext **) & l->data, context);
3446 /* Not found? Add */
3448 *contexts = g_list_prepend (*contexts, gst_context_ref (context));
3452 /* handle child messages:
3454 * This method is called synchronously when a child posts a message on
3457 * GST_MESSAGE_EOS: This message is only posted by sinks
3458 * in the PLAYING state. If all sinks posted the EOS message, post
3461 * GST_MESSAGE_STATE_DIRTY: Deprecated
3463 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3464 * element posts segment_start twice, only the last message is kept.
3466 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3467 * with the segment_done message. If there are no more segment_start
3468 * messages, post segment_done message upwards.
3470 * GST_MESSAGE_DURATION_CHANGED: clear any cached durations.
3471 * Whenever someone performs a duration query on the bin, we store the
3472 * result so we can answer it quicker the next time. Any element that
3473 * changes its duration marks our cached values invalid.
3474 * This message is also posted upwards. This is currently disabled
3475 * because too many elements don't post DURATION_CHANGED messages when
3476 * the duration changes.
3478 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3479 * can no longer provide a clock. The default bin behaviour is to
3480 * check if the lost clock was the one provided by the bin. If so and
3481 * we are currently in the PLAYING state, we forward the message to
3483 * This message is also generated when we remove a clock provider from
3484 * a bin. If this message is received by the application, it should
3485 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3486 * and a new base_time distribution.
3488 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3489 * can provide a clock. This mostly happens when we add a new clock
3490 * provider to the bin. The default behaviour of the bin is to mark the
3491 * currently selected clock as dirty, which will perform a clock
3492 * recalculation the next time we are asked to provide a clock.
3493 * This message is never sent to the application but is forwarded to
3496 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3497 * the state of the element and the fact that the element will need a
3498 * new base_time. This message is not forwarded to the application.
3500 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3501 * element when it posted ASYNC_START. If all elements are done, post a
3502 * ASYNC_DONE message to the parent.
3504 * OTHER: post upwards.
3507 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3510 GstMessageType type;
3511 GstMessage *tmessage;
3514 src = GST_MESSAGE_SRC (message);
3515 type = GST_MESSAGE_TYPE (message);
3517 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3518 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3519 GST_MESSAGE_TYPE_NAME (message));
3522 case GST_MESSAGE_ERROR:
3524 GST_OBJECT_LOCK (bin);
3526 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3527 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3528 GST_STATE_BROADCAST (bin);
3529 GST_OBJECT_UNLOCK (bin);
3533 case GST_MESSAGE_EOS:
3536 /* collect all eos messages from the children */
3537 bin_do_message_forward (bin, message);
3538 GST_OBJECT_LOCK (bin);
3539 /* ref message for future use */
3540 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3541 GST_OBJECT_UNLOCK (bin);
3546 case GST_MESSAGE_STREAM_START:
3549 /* collect all stream_start messages from the children */
3550 GST_OBJECT_LOCK (bin);
3551 /* ref message for future use */
3552 bin_replace_message (bin, message, GST_MESSAGE_STREAM_START);
3553 GST_OBJECT_UNLOCK (bin);
3555 bin_do_stream_start (bin);
3558 case GST_MESSAGE_STATE_DIRTY:
3560 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3563 gst_message_unref (message);
3566 case GST_MESSAGE_SEGMENT_START:{
3567 gboolean post = FALSE;
3571 gst_message_parse_segment_start (message, &format, &position);
3572 seqnum = gst_message_get_seqnum (message);
3574 bin_do_message_forward (bin, message);
3576 GST_OBJECT_LOCK (bin);
3577 /* if this is the first segment-start, post to parent but not to the
3579 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3580 (GST_OBJECT_PARENT (bin) != NULL)) {
3583 /* replace any previous segment_start message from this source
3584 * with the new segment start message */
3585 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3586 GST_OBJECT_UNLOCK (bin);
3588 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3590 gst_message_set_seqnum (tmessage, seqnum);
3592 /* post segment start with initial format and position. */
3593 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3595 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3599 case GST_MESSAGE_SEGMENT_DONE:
3601 gboolean post = FALSE;
3605 gst_message_parse_segment_done (message, &format, &position);
3606 seqnum = gst_message_get_seqnum (message);
3608 bin_do_message_forward (bin, message);
3610 GST_OBJECT_LOCK (bin);
3611 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3612 /* if there are no more segment_start messages, everybody posted
3613 * a segment_done and we can post one on the bus. */
3615 /* we don't care who still has a pending segment start */
3616 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3619 /* remove all old segment_done messages */
3620 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3622 GST_OBJECT_UNLOCK (bin);
3624 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3626 gst_message_set_seqnum (tmessage, seqnum);
3628 /* post segment done with latest format and position. */
3629 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3631 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3635 case GST_MESSAGE_DURATION_CHANGED:
3637 /* FIXME: remove all cached durations, next time somebody asks
3638 * for duration, we will recalculate. */
3640 GST_OBJECT_LOCK (bin);
3641 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION_CHANGED);
3642 GST_OBJECT_UNLOCK (bin);
3646 case GST_MESSAGE_CLOCK_LOST:
3648 GstClock **provided_clock_p;
3649 GstElement **clock_provider_p;
3650 gboolean playing, toplevel, provided, forward;
3653 gst_message_parse_clock_lost (message, &clock);
3655 GST_OBJECT_LOCK (bin);
3656 bin->clock_dirty = TRUE;
3657 /* if we lost the clock that we provided, post to parent but
3658 * only if we are not a top-level bin or PLAYING.
3659 * The reason for this is that applications should be able
3660 * to PAUSE/PLAY if they receive this message without worrying
3661 * about the state of the pipeline. */
3662 provided = (clock == bin->provided_clock);
3663 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3664 toplevel = GST_OBJECT_PARENT (bin) == NULL;
3665 forward = provided && (playing || !toplevel);
3667 GST_DEBUG_OBJECT (bin,
3668 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3669 bin->provided_clock, bin->clock_provider);
3670 provided_clock_p = &bin->provided_clock;
3671 clock_provider_p = &bin->clock_provider;
3672 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3673 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3675 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3676 provided, playing, forward);
3677 GST_OBJECT_UNLOCK (bin);
3683 gst_message_unref (message);
3686 case GST_MESSAGE_CLOCK_PROVIDE:
3690 GST_OBJECT_LOCK (bin);
3691 bin->clock_dirty = TRUE;
3692 /* a new clock is available, post to parent but not
3693 * to the application */
3694 forward = GST_OBJECT_PARENT (bin) != NULL;
3695 GST_OBJECT_UNLOCK (bin);
3701 gst_message_unref (message);
3704 case GST_MESSAGE_ASYNC_START:
3708 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3709 src ? GST_OBJECT_NAME (src) : "(NULL)");
3711 bin_do_message_forward (bin, message);
3713 GST_OBJECT_LOCK (bin);
3714 /* we ignore the message if we are going to <= READY */
3715 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3716 goto ignore_start_message;
3718 /* takes ownership of the message */
3719 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3721 bin_handle_async_start (bin);
3722 GST_OBJECT_UNLOCK (bin);
3725 ignore_start_message:
3727 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3728 gst_element_state_get_name (target));
3729 GST_OBJECT_UNLOCK (bin);
3730 gst_message_unref (message);
3734 case GST_MESSAGE_ASYNC_DONE:
3736 GstClockTime running_time;
3739 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3740 src ? GST_OBJECT_NAME (src) : "(NULL)");
3742 gst_message_parse_async_done (message, &running_time);
3744 bin_do_message_forward (bin, message);
3746 GST_OBJECT_LOCK (bin);
3747 /* ignore messages if we are shutting down */
3748 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3749 goto ignore_done_message;
3751 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3752 /* if there are no more ASYNC_START messages, everybody posted
3753 * a ASYNC_DONE and we can post one on the bus. When checking, we
3754 * don't care who still has a pending ASYNC_START */
3755 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3756 /* nothing found, remove all old ASYNC_DONE messages */
3757 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3759 GST_DEBUG_OBJECT (bin, "async elements commited");
3760 /* when we get an async done message when a state change was busy, we
3761 * need to set the pending_done flag so that at the end of the state
3762 * change we can see if we need to verify pending async elements, hence
3763 * the TRUE argument here. */
3764 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
3767 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3769 GST_OBJECT_UNLOCK (bin);
3772 ignore_done_message:
3774 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3775 gst_element_state_get_name (target));
3776 GST_OBJECT_UNLOCK (bin);
3777 gst_message_unref (message);
3781 case GST_MESSAGE_STRUCTURE_CHANGE:
3785 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3787 GST_OBJECT_LOCK (bin);
3789 /* while the pad is busy, avoid following it when doing state changes.
3790 * Don't update the cookie yet, we will do that after the structure
3791 * change finished and we are ready to inspect the new updated
3793 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3796 /* a pad link/unlink ended, signal the state change iterator that we
3797 * need to resync by updating the structure_cookie. */
3798 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3799 GST_MESSAGE_STRUCTURE_CHANGE);
3800 if (!GST_BIN_IS_NO_RESYNC (bin))
3801 bin->priv->structure_cookie++;
3803 GST_OBJECT_UNLOCK (bin);
3806 gst_message_unref (message);
3810 case GST_MESSAGE_NEED_CONTEXT:{
3811 const gchar *context_type;
3812 GList *l, *contexts;
3814 gst_message_parse_context_type (message, &context_type);
3815 GST_OBJECT_LOCK (bin);
3816 contexts = GST_ELEMENT_CAST (bin)->contexts;
3817 GST_LOG_OBJECT (bin, "got need-context message type: %s", context_type);
3818 for (l = contexts; l; l = l->next) {
3819 GstContext *tmp = l->data;
3820 const gchar *tmp_type = gst_context_get_context_type (tmp);
3822 if (strcmp (context_type, tmp_type) == 0) {
3823 gst_element_set_context (GST_ELEMENT (src), l->data);
3827 GST_OBJECT_UNLOCK (bin);
3829 /* Forward if we couldn't answer the message */
3833 gst_message_unref (message);
3838 case GST_MESSAGE_HAVE_CONTEXT:{
3839 GstContext *context;
3841 gst_message_parse_have_context (message, &context);
3842 gst_bin_update_context (bin, context);
3843 gst_context_unref (context);
3855 /* Send all other messages upward */
3856 GST_DEBUG_OBJECT (bin, "posting message upward");
3857 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3862 /* generic struct passed to all query fold methods */
3871 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3872 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3874 /* for duration/position we collect all durations/positions and take
3875 * the MAX of all valid results */
3877 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3885 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3887 gboolean res = FALSE;
3888 GstObject *item = g_value_get_object (vitem);
3889 if (GST_IS_PAD (item))
3890 res = gst_pad_query (GST_PAD (item), fold->query);
3892 res = gst_element_query (GST_ELEMENT (item), fold->query);
3897 g_value_set_boolean (ret, TRUE);
3899 gst_query_parse_duration (fold->query, NULL, &duration);
3901 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3903 if (duration == -1) {
3904 /* duration query succeeded, but duration is unknown */
3909 if (duration > fold->max)
3910 fold->max = duration;
3917 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3921 gst_query_parse_duration (fold->query, &format, NULL);
3922 /* store max in query result */
3923 gst_query_set_duration (fold->query, format, fold->max);
3925 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3927 /* FIXME: re-implement duration caching */
3930 GST_OBJECT_LOCK (bin);
3931 bin->messages = g_list_prepend (bin->messages,
3932 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3933 GST_OBJECT_UNLOCK (bin);
3938 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3940 gboolean res = FALSE;
3941 GstObject *item = g_value_get_object (vitem);
3942 if (GST_IS_PAD (item))
3943 res = gst_pad_query (GST_PAD (item), fold->query);
3945 res = gst_element_query (GST_ELEMENT (item), fold->query);
3950 g_value_set_boolean (ret, TRUE);
3952 gst_query_parse_position (fold->query, NULL, &position);
3954 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3956 if (position > fold->max)
3957 fold->max = position;
3964 bin_query_position_done (GstBin * bin, QueryFold * fold)
3968 gst_query_parse_position (fold->query, &format, NULL);
3969 /* store max in query result */
3970 gst_query_set_position (fold->query, format, fold->max);
3972 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3976 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3978 gboolean res = FALSE;
3979 GstObject *item = g_value_get_object (vitem);
3980 if (GST_IS_PAD (item))
3981 res = gst_pad_query (GST_PAD (item), fold->query);
3983 res = gst_element_query (GST_ELEMENT (item), fold->query);
3985 GstClockTime min, max;
3988 gst_query_parse_latency (fold->query, &live, &min, &max);
3990 GST_DEBUG_OBJECT (item,
3991 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3992 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3994 /* for the combined latency we collect the MAX of all min latencies and
3995 * the MIN of all max latencies */
3997 if (min > fold->min)
3999 if (fold->max == -1)
4001 else if (max < fold->max)
4007 g_value_set_boolean (ret, FALSE);
4008 GST_DEBUG_OBJECT (item, "failed query");
4015 bin_query_latency_done (GstBin * bin, QueryFold * fold)
4017 /* store max in query result */
4018 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
4020 GST_DEBUG_OBJECT (bin,
4021 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
4022 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
4026 /* generic fold, return first valid result */
4028 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
4030 gboolean res = FALSE;
4031 GstObject *item = g_value_get_object (vitem);
4032 if (GST_IS_PAD (item))
4033 res = gst_pad_query (GST_PAD (item), fold->query);
4035 res = gst_element_query (GST_ELEMENT (item), fold->query);
4037 g_value_set_boolean (ret, TRUE);
4038 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
4041 /* and stop as soon as we have a valid result */
4045 /* Perform a query iteration for the given bin. The query is stored in
4046 * QueryFold and iter should be either a GstPad iterator or a
4047 * GstElement iterator. */
4049 bin_iterate_fold (GstBin * bin, GstIterator * iter, QueryInitFunction fold_init,
4050 QueryDoneFunction fold_done, GstIteratorFoldFunction fold_func,
4051 QueryFold * fold_data, gboolean default_return)
4053 gboolean res = default_return;
4055 /* set the result of the query to FALSE initially */
4056 g_value_init (&ret, G_TYPE_BOOLEAN);
4057 g_value_set_boolean (&ret, res);
4060 GstIteratorResult ires;
4062 ires = gst_iterator_fold (iter, fold_func, &ret, fold_data);
4065 case GST_ITERATOR_RESYNC:
4066 gst_iterator_resync (iter);
4068 fold_init (bin, fold_data);
4069 g_value_set_boolean (&ret, res);
4071 case GST_ITERATOR_OK:
4072 case GST_ITERATOR_DONE:
4073 res = g_value_get_boolean (&ret);
4074 if (fold_done != NULL && res)
4075 fold_done (bin, fold_data);
4087 gst_bin_query (GstElement * element, GstQuery * query)
4089 GstBin *bin = GST_BIN_CAST (element);
4091 gboolean default_return = FALSE;
4092 gboolean res = FALSE;
4093 gboolean src_pads_query_result = FALSE;
4094 GstIteratorFoldFunction fold_func;
4095 QueryInitFunction fold_init = NULL;
4096 QueryDoneFunction fold_done = NULL;
4097 QueryFold fold_data;
4099 switch (GST_QUERY_TYPE (query)) {
4100 case GST_QUERY_DURATION:
4102 /* FIXME: implement duration caching in GstBin again */
4107 gst_query_parse_duration (query, &qformat, NULL);
4109 /* find cached duration query */
4110 GST_OBJECT_LOCK (bin);
4111 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
4112 GstMessage *message = (GstMessage *) cached->data;
4114 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION_CHANGED &&
4115 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
4119 gst_message_parse_duration (message, &format, &duration);
4121 /* if cached same format, copy duration in query result */
4122 if (format == qformat) {
4123 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
4125 GST_OBJECT_UNLOCK (bin);
4127 gst_query_set_duration (query, qformat, duration);
4133 GST_OBJECT_UNLOCK (bin);
4135 GST_FIXME ("implement duration caching in GstBin again");
4137 /* no cached value found, iterate and collect durations */
4138 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
4139 fold_init = bin_query_min_max_init;
4140 fold_done = bin_query_duration_done;
4143 case GST_QUERY_POSITION:
4145 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
4146 fold_init = bin_query_min_max_init;
4147 fold_done = bin_query_position_done;
4150 case GST_QUERY_LATENCY:
4152 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
4153 fold_init = bin_query_min_max_init;
4154 fold_done = bin_query_latency_done;
4155 default_return = TRUE;
4159 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
4163 fold_data.query = query;
4165 iter = gst_bin_iterate_sinks (bin);
4166 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
4167 query, GST_QUERY_TYPE_NAME (query));
4170 fold_init (bin, &fold_data);
4173 bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func, &fold_data,
4175 gst_iterator_free (iter);
4178 /* Query the source pads of the element */
4179 iter = gst_element_iterate_src_pads (element);
4180 src_pads_query_result =
4181 bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func,
4182 &fold_data, default_return);
4183 gst_iterator_free (iter);
4185 if (src_pads_query_result)
4189 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
4195 set_context (const GValue * item, gpointer user_data)
4197 GstElement *element = g_value_get_object (item);
4199 gst_element_set_context (element, user_data);
4203 gst_bin_set_context (GstElement * element, GstContext * context)
4206 GstIterator *children;
4208 g_return_if_fail (GST_IS_BIN (element));
4210 bin = GST_BIN (element);
4212 GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
4214 children = gst_bin_iterate_elements (bin);
4215 while (gst_iterator_foreach (children, set_context,
4216 context) == GST_ITERATOR_RESYNC)
4217 gst_iterator_resync (children);
4218 gst_iterator_free (children);
4222 compare_name (const GValue * velement, const gchar * name)
4225 GstElement *element = g_value_get_object (velement);
4227 GST_OBJECT_LOCK (element);
4228 eq = strcmp (GST_ELEMENT_NAME (element), name);
4229 GST_OBJECT_UNLOCK (element);
4235 * gst_bin_get_by_name:
4237 * @name: the element name to search for
4239 * Gets the element with the given name from a bin. This
4240 * function recurses into child bins.
4242 * Returns %NULL if no element with the given name is found in the bin.
4244 * MT safe. Caller owns returned reference.
4246 * Returns: (transfer full) (nullable): the #GstElement with the given
4250 gst_bin_get_by_name (GstBin * bin, const gchar * name)
4252 GstIterator *children;
4253 GValue result = { 0, };
4254 GstElement *element;
4257 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4259 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
4260 GST_ELEMENT_NAME (bin), name);
4262 children = gst_bin_iterate_recurse (bin);
4263 found = gst_iterator_find_custom (children,
4264 (GCompareFunc) compare_name, &result, (gpointer) name);
4265 gst_iterator_free (children);
4268 element = g_value_dup_object (&result);
4269 g_value_unset (&result);
4278 * gst_bin_get_by_name_recurse_up:
4280 * @name: the element name to search for
4282 * Gets the element with the given name from this bin. If the
4283 * element is not found, a recursion is performed on the parent bin.
4286 * - no element with the given name is found in the bin
4288 * MT safe. Caller owns returned reference.
4290 * Returns: (transfer full) (nullable): the #GstElement with the given
4294 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
4298 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4299 g_return_val_if_fail (name != NULL, NULL);
4301 result = gst_bin_get_by_name (bin, name);
4306 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
4308 if (GST_IS_BIN (parent)) {
4309 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
4311 gst_object_unref (parent);
4319 compare_interface (const GValue * velement, GValue * interface)
4321 GstElement *element = g_value_get_object (velement);
4322 GType interface_type = (GType) g_value_get_pointer (interface);
4325 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
4334 * gst_bin_get_by_interface:
4336 * @iface: the #GType of an interface
4338 * Looks for an element inside the bin that implements the given
4339 * interface. If such an element is found, it returns the element.
4340 * You can cast this element to the given interface afterwards. If you want
4341 * all elements that implement the interface, use
4342 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
4344 * MT safe. Caller owns returned reference.
4346 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
4349 gst_bin_get_by_interface (GstBin * bin, GType iface)
4351 GstIterator *children;
4352 GValue result = { 0, };
4353 GstElement *element;
4355 GValue viface = { 0, };
4357 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4358 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4360 g_value_init (&viface, G_TYPE_POINTER);
4361 g_value_set_pointer (&viface, (gpointer) iface);
4363 children = gst_bin_iterate_recurse (bin);
4364 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
4366 gst_iterator_free (children);
4369 element = g_value_dup_object (&result);
4370 g_value_unset (&result);
4374 g_value_unset (&viface);
4380 * gst_bin_iterate_all_by_interface:
4382 * @iface: the #GType of an interface
4384 * Looks for all elements inside the bin that implements the given
4385 * interface. You can safely cast all returned elements to the given interface.
4386 * The function recurses inside child bins. The iterator will yield a series
4387 * of #GstElement that should be unreffed after use.
4389 * MT safe. Caller owns returned value.
4391 * Returns: (transfer full) (nullable): a #GstIterator of #GstElement
4392 * for all elements in the bin implementing the given interface,
4396 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
4398 GstIterator *children;
4399 GstIterator *result;
4400 GValue viface = { 0, };
4402 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4403 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4405 g_value_init (&viface, G_TYPE_POINTER);
4406 g_value_set_pointer (&viface, (gpointer) iface);
4408 children = gst_bin_iterate_recurse (bin);
4409 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
4412 g_value_unset (&viface);