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.
157 * Last reviewed on 2012-03-28 (0.11.3)
160 #include "gst_private.h"
162 #include "gstevent.h"
165 #include "gsterror.h"
167 #include "gstutils.h"
168 #include "gstchildproxy.h"
170 GST_DEBUG_CATEGORY_STATIC (bin_debug);
171 #define GST_CAT_DEFAULT bin_debug
173 /* a bin is toplevel if it has no parent or when it is configured to behave like
175 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
177 #define GST_BIN_GET_PRIVATE(obj) \
178 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
180 struct _GstBinPrivate
182 gboolean asynchandling;
183 /* if we get an ASYNC_DONE message from ourselves, this means that the
184 * subclass will simulate ASYNC behaviour without having ASYNC children. When
185 * such an ASYNC_DONE message is posted while we are doing a state change, we
186 * have to process the message after finishing the state change even when no
187 * child returned GST_STATE_CHANGE_ASYNC. */
188 gboolean pending_async_done;
190 guint32 structure_cookie;
197 /* forward messages from our children */
198 gboolean message_forward;
210 static void gst_bin_dispose (GObject * object);
212 static void gst_bin_set_property (GObject * object, guint prop_id,
213 const GValue * value, GParamSpec * pspec);
214 static void gst_bin_get_property (GObject * object, guint prop_id,
215 GValue * value, GParamSpec * pspec);
217 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
218 GstStateChange transition);
219 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
220 GstState newstate, GstState pending);
221 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
222 GstState * state, GstState * pending, GstClockTime timeout);
223 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
224 gboolean flag_pending, GstClockTime running_time);
225 static void bin_handle_async_start (GstBin * bin);
226 static void bin_push_state_continue (BinContinueData * data);
227 static void bin_do_eos (GstBin * bin);
229 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
230 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
233 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
234 static GstIndex *gst_bin_get_index_func (GstElement * element);
237 static GstClock *gst_bin_provide_clock_func (GstElement * element);
238 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
240 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
241 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
242 static GstBusSyncReply bin_bus_handler (GstBus * bus,
243 GstMessage * message, GstBin * bin);
244 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
246 static gboolean gst_bin_do_latency_func (GstBin * bin);
248 static void bin_remove_messages (GstBin * bin, GstObject * src,
249 GstMessageType types);
250 static void gst_bin_continue_func (BinContinueData * data);
251 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
252 static gint bin_element_is_src (GstElement * child, GstBin * bin);
254 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
256 /* Bin signals and properties */
265 #define DEFAULT_ASYNC_HANDLING FALSE
266 #define DEFAULT_MESSAGE_FORWARD FALSE
272 PROP_MESSAGE_FORWARD,
276 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
278 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
282 static const GInterfaceInfo iface_info = { \
283 gst_bin_child_proxy_init, \
287 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
289 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
290 "debugging info for the 'bin' container element"); \
294 #define gst_bin_parent_class parent_class
295 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
298 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
304 bin = GST_BIN_CAST (child_proxy);
306 GST_OBJECT_LOCK (bin);
307 if ((res = g_list_nth_data (bin->children, index)))
308 gst_object_ref (res);
309 GST_OBJECT_UNLOCK (bin);
311 return (GObject *) res;
315 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
320 bin = GST_BIN_CAST (child_proxy);
322 GST_OBJECT_LOCK (bin);
323 num = bin->numchildren;
324 GST_OBJECT_UNLOCK (bin);
330 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
332 GstChildProxyInterface *iface = g_iface;
334 iface->get_children_count = gst_bin_child_proxy_get_children_count;
335 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
339 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
340 GValue * return_accu, const GValue * handler_return, gpointer dummy)
344 myboolean = g_value_get_boolean (handler_return);
345 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
346 g_value_set_boolean (return_accu, myboolean);
348 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
355 gst_bin_class_init (GstBinClass * klass)
357 GObjectClass *gobject_class;
358 GstElementClass *gstelement_class;
361 gobject_class = (GObjectClass *) klass;
362 gstelement_class = (GstElementClass *) klass;
364 g_type_class_add_private (klass, sizeof (GstBinPrivate));
366 gobject_class->set_property = gst_bin_set_property;
367 gobject_class->get_property = gst_bin_get_property;
370 * GstBin:async-handling:
372 * If set to #TRUE, the bin will handle asynchronous state changes.
373 * This should be used only if the bin subclass is modifying the state
374 * of its children on its own.
376 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
377 g_param_spec_boolean ("async-handling", "Async Handling",
378 "The bin will handle Asynchronous state changes",
379 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
382 * GstBin::element-added:
384 * @element: the #GstElement that was added to the bin
386 * Will be emitted after the element was added to the bin.
388 gst_bin_signals[ELEMENT_ADDED] =
389 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
390 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
391 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
393 * GstBin::element-removed:
395 * @element: the #GstElement that was removed from the bin
397 * Will be emitted after the element was removed from the bin.
399 gst_bin_signals[ELEMENT_REMOVED] =
400 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
401 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
402 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
404 * GstBin::do-latency:
407 * Will be emitted when the bin needs to perform latency calculations. This
408 * signal is only emited for toplevel bins or when async-handling is
411 * Only one signal handler is invoked. If no signals are connected, the
412 * default handler is invoked, which will query and distribute the lowest
413 * possible latency to all sinks.
415 * Connect to this signal if the default latency calculations are not
416 * sufficient, like when you need different latencies for different sinks in
419 gst_bin_signals[DO_LATENCY] =
420 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
421 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
422 _gst_boolean_accumulator, NULL, g_cclosure_marshal_generic,
423 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
426 * GstBin:message-forward:
428 * Forward all children messages, even those that would normally be filtered by
429 * the bin. This can be interesting when one wants to be notified of the EOS
430 * state of individual elements, for example.
432 * The messages are converted to an ELEMENT message with the bin as the
433 * source. The structure of the message is named 'GstBinForwarded' and contains
434 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
437 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
438 g_param_spec_boolean ("message-forward", "Message Forward",
439 "Forwards all children messages",
440 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
442 gobject_class->dispose = gst_bin_dispose;
444 gst_element_class_set_static_metadata (gstelement_class, "Generic bin",
446 "Simple container object",
447 "Erik Walthinsen <omega@cse.ogi.edu>,"
448 "Wim Taymans <wim.taymans@gmail.com>");
450 gstelement_class->change_state =
451 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
452 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
453 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
455 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
456 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
458 gstelement_class->provide_clock =
459 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
460 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
462 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
463 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
465 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
466 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
467 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
469 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
471 GST_DEBUG ("creating bin thread pool");
474 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
476 g_critical ("could alloc threadpool %s", err->message);
481 gst_bin_init (GstBin * bin)
485 bin->numchildren = 0;
486 bin->children = NULL;
487 bin->children_cookie = 0;
488 bin->messages = NULL;
489 bin->provided_clock = NULL;
490 bin->clock_dirty = FALSE;
492 /* Set up a bus for listening to child elements */
493 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
494 bin->child_bus = bus;
495 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
497 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin,
500 bin->priv = GST_BIN_GET_PRIVATE (bin);
501 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
502 bin->priv->structure_cookie = 0;
503 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
507 gst_bin_dispose (GObject * object)
509 GstBin *bin = GST_BIN_CAST (object);
510 GstBus **child_bus_p = &bin->child_bus;
511 GstClock **provided_clock_p = &bin->provided_clock;
512 GstElement **clock_provider_p = &bin->clock_provider;
514 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
516 GST_OBJECT_LOCK (object);
517 gst_object_replace ((GstObject **) child_bus_p, NULL);
518 gst_object_replace ((GstObject **) provided_clock_p, NULL);
519 gst_object_replace ((GstObject **) clock_provider_p, NULL);
520 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
521 GST_OBJECT_UNLOCK (object);
523 while (bin->children) {
524 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
526 if (G_UNLIKELY (bin->children != NULL)) {
527 g_critical ("could not remove elements from bin '%s'",
528 GST_STR_NULL (GST_OBJECT_NAME (object)));
531 G_OBJECT_CLASS (parent_class)->dispose (object);
536 * @name: the name of the new bin
538 * Creates a new bin with the given name.
540 * Returns: (transfer floating): a new #GstBin
543 gst_bin_new (const gchar * name)
545 return gst_element_factory_make ("bin", name);
549 gst_bin_set_property (GObject * object, guint prop_id,
550 const GValue * value, GParamSpec * pspec)
554 gstbin = GST_BIN_CAST (object);
557 case PROP_ASYNC_HANDLING:
558 GST_OBJECT_LOCK (gstbin);
559 gstbin->priv->asynchandling = g_value_get_boolean (value);
560 GST_OBJECT_UNLOCK (gstbin);
562 case PROP_MESSAGE_FORWARD:
563 GST_OBJECT_LOCK (gstbin);
564 gstbin->priv->message_forward = g_value_get_boolean (value);
565 GST_OBJECT_UNLOCK (gstbin);
568 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
574 gst_bin_get_property (GObject * object, guint prop_id,
575 GValue * value, GParamSpec * pspec)
579 gstbin = GST_BIN_CAST (object);
582 case PROP_ASYNC_HANDLING:
583 GST_OBJECT_LOCK (gstbin);
584 g_value_set_boolean (value, gstbin->priv->asynchandling);
585 GST_OBJECT_UNLOCK (gstbin);
587 case PROP_MESSAGE_FORWARD:
588 GST_OBJECT_LOCK (gstbin);
589 g_value_set_boolean (value, gstbin->priv->message_forward);
590 GST_OBJECT_UNLOCK (gstbin);
593 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
599 /* return the cached index */
601 gst_bin_get_index_func (GstElement * element)
606 bin = GST_BIN_CAST (element);
608 GST_OBJECT_LOCK (bin);
609 if ((result = bin->priv->index))
610 gst_object_ref (result);
611 GST_OBJECT_UNLOCK (bin);
616 /* set the index on all elements in this bin
621 gst_bin_set_index_func (GstElement * element, GstIndex * index)
627 GValue data = { 0, };
629 bin = GST_BIN_CAST (element);
631 GST_OBJECT_LOCK (bin);
632 old = bin->priv->index;
633 if (G_UNLIKELY (old == index))
636 gst_object_ref (index);
637 bin->priv->index = index;
638 GST_OBJECT_UNLOCK (bin);
641 gst_object_unref (old);
643 it = gst_bin_iterate_elements (bin);
645 /* set the index on all elements in the bin */
648 switch (gst_iterator_next (it, &data)) {
649 case GST_ITERATOR_OK:
651 GstElement *child = g_value_get_object (&data);
653 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
654 GST_ELEMENT_NAME (child));
655 gst_element_set_index (child, index);
657 g_value_reset (&data);
660 case GST_ITERATOR_RESYNC:
661 GST_DEBUG_OBJECT (bin, "iterator doing resync");
662 gst_iterator_resync (it);
665 case GST_ITERATOR_DONE:
666 GST_DEBUG_OBJECT (bin, "iterator done");
671 g_value_unset (&data);
672 gst_iterator_free (it);
677 GST_DEBUG_OBJECT (bin, "index was already set");
678 GST_OBJECT_UNLOCK (bin);
684 /* set the clock on all elements in this bin
689 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
695 GValue data = { 0, };
697 bin = GST_BIN_CAST (element);
699 it = gst_bin_iterate_elements (bin);
703 switch (gst_iterator_next (it, &data)) {
704 case GST_ITERATOR_OK:
706 GstElement *child = g_value_get_object (&data);
708 res &= gst_element_set_clock (child, clock);
710 g_value_reset (&data);
713 case GST_ITERATOR_RESYNC:
714 GST_DEBUG_OBJECT (bin, "iterator doing resync");
715 gst_iterator_resync (it);
719 case GST_ITERATOR_DONE:
720 GST_DEBUG_OBJECT (bin, "iterator done");
725 g_value_unset (&data);
726 gst_iterator_free (it);
729 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
734 /* get the clock for this bin by asking all of the children in this bin
736 * The ref of the returned clock in increased so unref after usage.
738 * We loop the elements in state order and pick the last clock we can
739 * get. This makes sure we get a clock from the source.
744 gst_bin_provide_clock_func (GstElement * element)
746 GstClock *result = NULL;
747 GstElement *provider = NULL;
752 GstClock **provided_clock_p;
753 GstElement **clock_provider_p;
755 bin = GST_BIN_CAST (element);
757 GST_OBJECT_LOCK (bin);
758 if (!bin->clock_dirty)
761 GST_DEBUG_OBJECT (bin, "finding new clock");
763 it = gst_bin_sort_iterator_new (bin);
764 GST_OBJECT_UNLOCK (bin);
768 switch (gst_iterator_next (it, &val)) {
769 case GST_ITERATOR_OK:
771 GstElement *child = g_value_get_object (&val);
774 clock = gst_element_provide_clock (child);
776 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
777 clock, GST_ELEMENT_NAME (child));
779 gst_object_unref (result);
780 gst_object_unref (provider);
783 provider = gst_object_ref (child);
786 g_value_reset (&val);
789 case GST_ITERATOR_RESYNC:
790 gst_iterator_resync (it);
793 case GST_ITERATOR_DONE:
798 g_value_unset (&val);
799 gst_iterator_free (it);
801 GST_OBJECT_LOCK (bin);
802 if (!bin->clock_dirty) {
804 gst_object_unref (provider);
806 gst_object_unref (result);
812 provided_clock_p = &bin->provided_clock;
813 clock_provider_p = &bin->clock_provider;
814 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
815 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
816 bin->clock_dirty = FALSE;
817 GST_DEBUG_OBJECT (bin,
818 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
820 /* Provider is not being returned to caller, just the result */
822 gst_object_unref (provider);
823 GST_OBJECT_UNLOCK (bin);
829 if ((result = bin->provided_clock))
830 gst_object_ref (result);
831 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
832 GST_OBJECT_UNLOCK (bin);
839 * functions for manipulating cached messages
844 GstMessageType types;
847 /* check if a message is of given src and type */
849 message_check (GstMessage * message, MessageFind * target)
854 eq &= GST_MESSAGE_SRC (message) == target->src;
856 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
857 GST_LOG ("looking at message %p: %d", message, eq);
863 find_message (GstBin * bin, GstObject * src, GstMessageType types)
871 result = g_list_find_custom (bin->messages, &find,
872 (GCompareFunc) message_check);
875 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
876 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
879 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
880 #ifndef GST_DISABLE_GST_DEBUG
884 for (i = 0; i < 32; i++)
885 if (types & (1 << i))
886 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
894 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
897 * A message that is cached and has the same SRC and type is replaced
898 * by the given message.
901 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
907 if ((src = GST_MESSAGE_SRC (message))) {
908 /* first find the previous message posted by this element */
909 if ((previous = find_message (bin, src, types))) {
910 GstMessage *previous_msg;
912 /* if we found a previous message, replace it */
913 previous_msg = previous->data;
914 previous->data = message;
916 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
917 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
918 GST_MESSAGE_TYPE_NAME (message));
920 gst_message_unref (previous_msg);
922 /* keep new message */
923 bin->messages = g_list_prepend (bin->messages, message);
925 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
926 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
929 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
930 GST_MESSAGE_TYPE_NAME (message));
932 gst_message_unref (message);
937 /* with LOCK. Remove all messages of given types */
939 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
947 for (walk = bin->messages; walk; walk = next) {
948 GstMessage *message = (GstMessage *) walk->data;
950 next = g_list_next (walk);
952 if (message_check (message, &find) == 0) {
953 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
954 "deleting message %p of types 0x%08x", message, types);
955 bin->messages = g_list_delete_link (bin->messages, walk);
956 gst_message_unref (message);
958 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
959 "not deleting message %p of type 0x%08x", message,
960 GST_MESSAGE_TYPE (message));
966 /* Check if the bin is EOS. We do this by scanning all sinks and
967 * checking if they posted an EOS message.
969 * call with bin LOCK */
971 is_eos (GstBin * bin, guint32 * seqnum)
978 for (walk = bin->children; walk; walk = g_list_next (walk)) {
981 element = GST_ELEMENT_CAST (walk->data);
982 if (bin_element_is_sink (element, bin) == 0) {
983 /* check if element posted EOS */
985 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
986 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
987 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
990 GST_DEBUG ("sink '%s' did not post EOS yet",
991 GST_ELEMENT_NAME (element));
997 /* FIXME: Some tests (e.g. elements/capsfilter) use
998 * pipelines with a dangling sinkpad but no sink element.
999 * These tests assume that no EOS message is ever
1000 * posted on the bus so let's keep that behaviour.
1001 * In valid pipelines this doesn't make a difference.
1003 return result && n_eos > 0;
1007 /* Check if the bin is STREAM_START. We do this by scanning all sinks and
1008 * checking if they posted an STREAM_START message.
1010 * call with bin LOCK */
1012 is_stream_start (GstBin * bin, guint32 * seqnum)
1015 gint n_stream_start = 0;
1019 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1020 GstElement *element;
1022 element = GST_ELEMENT_CAST (walk->data);
1023 if (bin_element_is_sink (element, bin) == 0) {
1024 /* check if element posted STREAM_START */
1026 find_message (bin, GST_OBJECT_CAST (element),
1027 GST_MESSAGE_STREAM_START))) {
1028 GST_DEBUG ("sink '%s' posted STREAM_START", GST_ELEMENT_NAME (element));
1029 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1032 GST_DEBUG ("sink '%s' did not post STREAM_START yet",
1033 GST_ELEMENT_NAME (element));
1044 unlink_pads (const GValue * item, gpointer user_data)
1049 pad = g_value_get_object (item);
1051 if ((peer = gst_pad_get_peer (pad))) {
1052 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1053 gst_pad_unlink (pad, peer);
1055 gst_pad_unlink (peer, pad);
1056 gst_object_unref (peer);
1060 /* vmethod that adds an element to a bin
1065 gst_bin_add_func (GstBin * bin, GstElement * element)
1069 gboolean is_sink, is_source, provides_clock, requires_clock;
1070 GstMessage *clock_message = NULL, *async_message = NULL;
1071 GstStateChangeReturn ret;
1073 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1075 /* we obviously can't add ourself to ourself */
1076 if (G_UNLIKELY (element == GST_ELEMENT_CAST (bin)))
1079 /* get the element name to make sure it is unique in this bin. */
1080 GST_OBJECT_LOCK (element);
1081 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1082 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1083 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1085 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1087 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1088 GST_OBJECT_UNLOCK (element);
1090 GST_OBJECT_LOCK (bin);
1092 /* then check to see if the element's name is already taken in the bin,
1093 * we can safely take the lock here. This check is probably bogus because
1094 * you can safely change the element name after this check and before setting
1095 * the object parent. The window is very small though... */
1096 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1097 goto duplicate_name;
1099 /* set the element's parent and add the element to the bin's list of children */
1100 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1101 GST_OBJECT_CAST (bin))))
1104 /* if we add a sink we become a sink */
1106 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1108 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1111 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1113 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1115 if (provides_clock) {
1116 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1118 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1119 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1121 if (requires_clock) {
1122 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1123 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1126 bin->children = g_list_prepend (bin->children, element);
1128 bin->children_cookie++;
1129 if (!GST_BIN_IS_NO_RESYNC (bin))
1130 bin->priv->structure_cookie++;
1132 /* distribute the bus */
1133 gst_element_set_bus (element, bin->child_bus);
1135 /* propagate the current base_time, start_time and clock */
1136 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1137 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1138 /* it's possible that the element did not accept the clock but
1139 * that is not important right now. When the pipeline goes to PLAYING,
1140 * a new clock will be selected */
1141 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1144 /* set the cached index on the children */
1145 if (bin->priv->index)
1146 gst_element_set_index (element, bin->priv->index);
1149 ret = GST_STATE_RETURN (bin);
1150 /* no need to update the state if we are in error */
1151 if (ret == GST_STATE_CHANGE_FAILURE)
1152 goto no_state_recalc;
1154 /* update the bin state, the new element could have been an ASYNC or
1155 * NO_PREROLL element */
1156 ret = GST_STATE_RETURN (element);
1157 GST_DEBUG_OBJECT (bin, "added %s element",
1158 gst_element_state_change_return_get_name (ret));
1161 case GST_STATE_CHANGE_ASYNC:
1163 /* create message to track this aync element when it posts an async-done
1165 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1168 case GST_STATE_CHANGE_NO_PREROLL:
1169 /* ignore all async elements we might have and commit our state */
1170 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1172 case GST_STATE_CHANGE_FAILURE:
1179 GST_OBJECT_UNLOCK (bin);
1181 /* post the messages on the bus of the element so that the bin can handle
1184 gst_element_post_message (element, clock_message);
1187 gst_element_post_message (element, async_message);
1189 /* unlink all linked pads */
1190 it = gst_element_iterate_pads (element);
1191 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1192 gst_iterator_free (it);
1194 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1197 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1198 gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
1205 /* ERROR handling here */
1208 GST_OBJECT_LOCK (bin);
1209 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1210 GST_OBJECT_UNLOCK (bin);
1215 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1216 elem_name, GST_ELEMENT_NAME (bin));
1217 GST_OBJECT_UNLOCK (bin);
1223 g_warning ("Element '%s' already has parent", elem_name);
1224 GST_OBJECT_UNLOCK (bin);
1233 * @element: (transfer full): the #GstElement to add
1235 * Adds the given element to the bin. Sets the element's parent, and thus
1236 * takes ownership of the element. An element can only be added to one bin.
1238 * If the element's pads are linked to other pads, the pads will be unlinked
1239 * before the element is added to the bin.
1242 * When you add an element to an already-running pipeline, you will have to
1243 * take care to set the state of the newly-added element to the desired
1244 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1245 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1246 * The bin or pipeline will not take care of this for you.
1251 * Returns: TRUE if the element could be added, FALSE if
1252 * the bin does not want to accept the element.
1255 gst_bin_add (GstBin * bin, GstElement * element)
1257 GstBinClass *bclass;
1260 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1261 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1263 bclass = GST_BIN_GET_CLASS (bin);
1265 if (G_UNLIKELY (bclass->add_element == NULL))
1268 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1269 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1270 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1272 result = bclass->add_element (bin, element);
1276 /* ERROR handling */
1279 g_warning ("adding elements to bin '%s' is not supported",
1280 GST_ELEMENT_NAME (bin));
1285 /* remove an element from the bin
1290 gst_bin_remove_func (GstBin * bin, GstElement * element)
1294 gboolean is_sink, is_source, provides_clock, requires_clock;
1295 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1296 GstMessage *clock_message = NULL;
1297 GstClock **provided_clock_p;
1298 GstElement **clock_provider_p;
1300 gboolean other_async, this_async, have_no_preroll;
1301 GstStateChangeReturn ret;
1303 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1305 GST_OBJECT_LOCK (bin);
1307 GST_OBJECT_LOCK (element);
1308 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1310 if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
1313 /* remove the parent ref */
1314 GST_OBJECT_PARENT (element) = NULL;
1316 /* grab element name so we can print it */
1317 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1318 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1320 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1322 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1323 GST_OBJECT_UNLOCK (element);
1327 othersource = FALSE;
1328 otherprovider = FALSE;
1329 otherrequirer = FALSE;
1330 have_no_preroll = FALSE;
1331 /* iterate the elements, we collect which ones are async and no_preroll. We
1332 * also remove the element when we find it. */
1333 for (walk = bin->children; walk; walk = next) {
1334 GstElement *child = GST_ELEMENT_CAST (walk->data);
1336 next = g_list_next (walk);
1338 if (child == element) {
1340 /* remove the element */
1341 bin->children = g_list_delete_link (bin->children, walk);
1343 gboolean child_sink, child_source, child_provider, child_requirer;
1345 GST_OBJECT_LOCK (child);
1346 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1347 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1349 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1351 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1352 /* when we remove a sink, check if there are other sinks. */
1353 if (is_sink && !othersink && child_sink)
1355 if (is_source && !othersource && child_source)
1357 if (provides_clock && !otherprovider && child_provider)
1358 otherprovider = TRUE;
1359 if (requires_clock && !otherrequirer && child_requirer)
1360 otherrequirer = TRUE;
1361 /* check if we have NO_PREROLL children */
1362 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1363 have_no_preroll = TRUE;
1364 GST_OBJECT_UNLOCK (child);
1368 /* the element must have been in the bin's list of children */
1369 if (G_UNLIKELY (!found))
1372 /* we now removed the element from the list of elements, increment the cookie
1373 * so that others can detect a change in the children list. */
1375 bin->children_cookie++;
1376 if (!GST_BIN_IS_NO_RESYNC (bin))
1377 bin->priv->structure_cookie++;
1379 if (is_sink && !othersink) {
1380 /* we're not a sink anymore */
1381 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1382 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1384 if (is_source && !othersource) {
1385 /* we're not a source anymore */
1386 GST_DEBUG_OBJECT (bin, "we removed the last source");
1387 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1389 if (provides_clock && !otherprovider) {
1390 /* we're not a clock provider anymore */
1391 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1392 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1394 if (requires_clock && !otherrequirer) {
1395 /* we're not a clock requirer anymore */
1396 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1397 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1400 /* if the clock provider for this element is removed, we lost
1401 * the clock as well, we need to inform the parent of this
1402 * so that it can select a new clock */
1403 if (bin->clock_provider == element) {
1404 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1405 bin->clock_dirty = TRUE;
1407 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1408 provided_clock_p = &bin->provided_clock;
1409 clock_provider_p = &bin->clock_provider;
1410 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1411 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1414 /* remove messages for the element, if there was a pending ASYNC_START
1415 * message we must see if removing the element caused the bin to lose its
1418 other_async = FALSE;
1419 for (walk = bin->messages; walk; walk = next) {
1420 GstMessage *message = (GstMessage *) walk->data;
1421 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1424 next = g_list_next (walk);
1427 switch (GST_MESSAGE_TYPE (message)) {
1428 case GST_MESSAGE_ASYNC_START:
1434 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1436 case GST_MESSAGE_STRUCTURE_CHANGE:
1440 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1442 /* it's unlikely that this message is still in the list of messages
1443 * because this would mean that a link/unlink is busy in another thread
1444 * while we remove the element. We still have to remove the message
1445 * because we might not receive the done message anymore when the element
1446 * is removed from the bin. */
1447 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1448 if (owner == element)
1459 /* delete all message types */
1460 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1461 message, elem_name);
1462 bin->messages = g_list_delete_link (bin->messages, walk);
1463 gst_message_unref (message);
1467 /* get last return */
1468 ret = GST_STATE_RETURN (bin);
1470 /* no need to update the state if we are in error */
1471 if (ret == GST_STATE_CHANGE_FAILURE)
1472 goto no_state_recalc;
1474 if (!other_async && this_async) {
1475 /* all other elements were not async and we removed the async one,
1476 * handle the async-done case because we are not async anymore now. */
1477 GST_DEBUG_OBJECT (bin,
1478 "we removed the last async element, have no_preroll %d",
1481 /* the current state return of the bin depends on if there are no_preroll
1482 * elements in the pipeline or not */
1483 if (have_no_preroll)
1484 ret = GST_STATE_CHANGE_NO_PREROLL;
1486 ret = GST_STATE_CHANGE_SUCCESS;
1488 bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
1490 GST_DEBUG_OBJECT (bin,
1491 "recalc state preroll: %d, other async: %d, this async %d",
1492 have_no_preroll, other_async, this_async);
1494 if (have_no_preroll) {
1495 ret = GST_STATE_CHANGE_NO_PREROLL;
1496 } else if (other_async) {
1497 /* there are other async elements and we were not doing an async state
1498 * change, change our pending state and go async */
1499 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1500 GST_STATE_NEXT (bin) = GST_STATE (bin);
1501 GST_STATE_PENDING (bin) = GST_STATE (bin);
1503 ret = GST_STATE_CHANGE_ASYNC;
1505 GST_STATE_RETURN (bin) = ret;
1509 gst_element_set_bus (element, NULL);
1510 /* Clear the clock we provided to the element */
1511 gst_element_set_clock (element, NULL);
1512 GST_OBJECT_UNLOCK (bin);
1515 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1517 /* unlink all linked pads */
1518 it = gst_element_iterate_pads (element);
1519 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1520 gst_iterator_free (it);
1522 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1525 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1526 gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
1530 /* element is really out of our control now */
1531 gst_object_unref (element);
1535 /* ERROR handling */
1538 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1539 GST_ELEMENT_NAME (bin));
1540 GST_OBJECT_UNLOCK (element);
1541 GST_OBJECT_UNLOCK (bin);
1550 * @element: (transfer none): the #GstElement to remove
1552 * Removes the element from the bin, unparenting it as well.
1553 * Unparenting the element means that the element will be dereferenced,
1554 * so if the bin holds the only reference to the element, the element
1555 * will be freed in the process of removing it from the bin. If you
1556 * want the element to still exist after removing, you need to call
1557 * gst_object_ref() before removing it from the bin.
1559 * If the element's pads are linked to other pads, the pads will be unlinked
1560 * before the element is removed from the bin.
1564 * Returns: TRUE if the element could be removed, FALSE if
1565 * the bin does not want to remove the element.
1568 gst_bin_remove (GstBin * bin, GstElement * element)
1570 GstBinClass *bclass;
1573 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1574 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1576 bclass = GST_BIN_GET_CLASS (bin);
1578 if (G_UNLIKELY (bclass->remove_element == NULL))
1581 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1582 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1584 result = bclass->remove_element (bin, element);
1588 /* ERROR handling */
1591 g_warning ("removing elements from bin '%s' is not supported",
1592 GST_ELEMENT_NAME (bin));
1598 * gst_bin_iterate_elements:
1601 * Gets an iterator for the elements in this bin.
1603 * Each element yielded by the iterator will have its refcount increased, so
1606 * MT safe. Caller owns returned value.
1608 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1611 gst_bin_iterate_elements (GstBin * bin)
1613 GstIterator *result;
1615 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1617 GST_OBJECT_LOCK (bin);
1618 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1619 GST_OBJECT_GET_LOCK (bin),
1620 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1621 GST_OBJECT_UNLOCK (bin);
1626 static GstIteratorItem
1627 iterate_child_recurse (GstIterator * it, const GValue * item)
1629 GstElement *child = g_value_get_object (item);
1631 if (GST_IS_BIN (child)) {
1632 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1634 gst_iterator_push (it, other);
1636 return GST_ITERATOR_ITEM_PASS;
1640 * gst_bin_iterate_recurse:
1643 * Gets an iterator for the elements in this bin.
1644 * This iterator recurses into GstBin children.
1646 * Each element yielded by the iterator will have its refcount increased, so
1649 * MT safe. Caller owns returned value.
1651 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1654 gst_bin_iterate_recurse (GstBin * bin)
1656 GstIterator *result;
1658 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1660 GST_OBJECT_LOCK (bin);
1661 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1662 GST_OBJECT_GET_LOCK (bin),
1663 &bin->children_cookie,
1665 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1666 GST_OBJECT_UNLOCK (bin);
1671 /* returns 0 when TRUE because this is a GCompareFunc */
1674 bin_element_is_sink (GstElement * child, GstBin * bin)
1678 /* we lock the child here for the remainder of the function to
1679 * get its name and flag safely. */
1680 GST_OBJECT_LOCK (child);
1681 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1683 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1684 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1686 GST_OBJECT_UNLOCK (child);
1687 return is_sink ? 0 : 1;
1691 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1693 GstBin *bin = g_value_get_object (vbin);
1694 GstElement *child = g_value_get_object (vchild);
1696 return (bin_element_is_sink (child, bin));
1700 * gst_bin_iterate_sinks:
1703 * Gets an iterator for all elements in the bin that have the
1704 * #GST_ELEMENT_FLAG_SINK flag set.
1706 * Each element yielded by the iterator will have its refcount increased, so
1709 * MT safe. Caller owns returned value.
1711 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1714 gst_bin_iterate_sinks (GstBin * bin)
1716 GstIterator *children;
1717 GstIterator *result;
1718 GValue vbin = { 0, };
1720 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1722 g_value_init (&vbin, GST_TYPE_BIN);
1723 g_value_set_object (&vbin, bin);
1725 children = gst_bin_iterate_elements (bin);
1726 result = gst_iterator_filter (children,
1727 (GCompareFunc) sink_iterator_filter, &vbin);
1729 g_value_unset (&vbin);
1734 /* returns 0 when TRUE because this is a GCompareFunc */
1737 bin_element_is_src (GstElement * child, GstBin * bin)
1741 /* we lock the child here for the remainder of the function to
1742 * get its name and other info safely. */
1743 GST_OBJECT_LOCK (child);
1744 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1746 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1747 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1749 GST_OBJECT_UNLOCK (child);
1750 return is_src ? 0 : 1;
1754 src_iterator_filter (const GValue * vchild, GValue * vbin)
1756 GstBin *bin = g_value_get_object (vbin);
1757 GstElement *child = g_value_get_object (vchild);
1759 return (bin_element_is_src (child, bin));
1763 * gst_bin_iterate_sources:
1766 * Gets an iterator for all elements in the bin that have the
1767 * #GST_ELEMENT_FLAG_SOURCE flag set.
1769 * Each element yielded by the iterator will have its refcount increased, so
1772 * MT safe. Caller owns returned value.
1774 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1777 gst_bin_iterate_sources (GstBin * bin)
1779 GstIterator *children;
1780 GstIterator *result;
1781 GValue vbin = { 0, };
1783 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1785 g_value_init (&vbin, GST_TYPE_BIN);
1786 g_value_set_object (&vbin, bin);
1788 children = gst_bin_iterate_elements (bin);
1789 result = gst_iterator_filter (children,
1790 (GCompareFunc) src_iterator_filter, &vbin);
1792 g_value_unset (&vbin);
1800 static GstStateChangeReturn
1801 gst_bin_get_state_func (GstElement * element, GstState * state,
1802 GstState * pending, GstClockTime timeout)
1804 GstStateChangeReturn ret;
1806 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1809 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1815 /***********************************************
1816 * Topologically sorted iterator
1817 * see http://en.wikipedia.org/wiki/Topological_sorting
1819 * For each element in the graph, an entry is kept in a HashTable
1820 * with its number of srcpad connections (degree).
1821 * We then change state of all elements without dependencies
1822 * (degree 0) and decrement the degree of all elements connected
1823 * on the sinkpads. When an element reaches degree 0, its state is
1825 * When all elements are handled the algorithm stops.
1827 typedef struct _GstBinSortIterator
1830 GQueue queue; /* elements queued for state change */
1831 GstBin *bin; /* bin we iterate */
1832 gint mode; /* adding or removing dependency */
1833 GstElement *best; /* next element with least dependencies */
1834 gint best_deg; /* best degree */
1835 GHashTable *hash; /* hashtable with element dependencies */
1836 gboolean dirty; /* we detected structure change */
1837 } GstBinSortIterator;
1840 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1841 GstBinSortIterator * copy)
1843 GHashTableIter iter;
1844 gpointer key, value;
1846 copy->queue = it->queue;
1847 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1849 copy->bin = gst_object_ref (it->bin);
1851 copy->best = gst_object_ref (it->best);
1853 copy->hash = g_hash_table_new (NULL, NULL);
1854 g_hash_table_iter_init (&iter, it->hash);
1855 while (g_hash_table_iter_next (&iter, &key, &value))
1856 g_hash_table_insert (copy->hash, key, value);
1859 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1860 #define HASH_SET_DEGREE(bit, elem, deg) \
1861 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1862 #define HASH_GET_DEGREE(bit, elem) \
1863 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1865 /* add element to queue of next elements in the iterator.
1866 * We push at the tail to give higher priority elements a
1869 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1871 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1872 GST_ELEMENT_NAME (element));
1873 gst_object_ref (element);
1874 g_queue_push_tail (&bit->queue, element);
1875 HASH_SET_DEGREE (bit, element, -1);
1879 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1883 if ((find = g_queue_find (&bit->queue, element))) {
1884 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1885 GST_ELEMENT_NAME (element));
1887 g_queue_delete_link (&bit->queue, find);
1888 gst_object_unref (element);
1890 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1891 GST_ELEMENT_NAME (element));
1895 /* clear the queue, unref all objects as we took a ref when
1896 * we added them to the queue */
1898 clear_queue (GQueue * queue)
1902 while ((p = g_queue_pop_head (queue)))
1903 gst_object_unref (p);
1906 /* set all degrees to 0. Elements marked as a sink are
1907 * added to the queue immediately. Since we only look at the SINK flag of the
1908 * element, it is possible that we add non-sinks to the queue. These will be
1909 * removed from the queue again when we can prove that it provides data for some
1912 reset_degree (GstElement * element, GstBinSortIterator * bit)
1916 /* sinks are added right away */
1917 GST_OBJECT_LOCK (element);
1918 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1919 GST_OBJECT_UNLOCK (element);
1922 add_to_queue (bit, element);
1924 /* others are marked with 0 and handled when sinks are done */
1925 HASH_SET_DEGREE (bit, element, 0);
1929 /* adjust the degree of all elements connected to the given
1930 * element. If a degree of an element drops to 0, it is
1931 * added to the queue of elements to schedule next.
1933 * We have to make sure not to cross the bin boundary this element
1937 update_degree (GstElement * element, GstBinSortIterator * bit)
1939 gboolean linked = FALSE;
1941 GST_OBJECT_LOCK (element);
1942 /* don't touch degree if element has no sinkpads */
1943 if (element->numsinkpads != 0) {
1944 /* loop over all sinkpads, decrement degree for all connected
1945 * elements in this bin */
1948 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1951 pad = GST_PAD_CAST (pads->data);
1953 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1954 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1955 GST_MESSAGE_STRUCTURE_CHANGE))) {
1956 /* mark the iterator as dirty because we won't be updating the degree
1957 * of the peer parent now. This would result in the 'loop detected'
1958 * later on because the peer parent element could become the best next
1959 * element with a degree > 0. We will simply continue our state
1960 * changes and we'll eventually resync when the unlink completed and
1961 * the iterator cookie is updated. */
1966 if ((peer = gst_pad_get_peer (pad))) {
1967 GstElement *peer_element;
1969 if ((peer_element = gst_pad_get_parent_element (peer))) {
1970 GST_OBJECT_LOCK (peer_element);
1971 /* check that we don't go outside of this bin */
1972 if (GST_OBJECT_CAST (peer_element)->parent ==
1973 GST_OBJECT_CAST (bit->bin)) {
1974 gint old_deg, new_deg;
1976 old_deg = HASH_GET_DEGREE (bit, peer_element);
1978 /* check to see if we added an element as sink that was not really a
1979 * sink because it was connected to some other element. */
1980 if (old_deg == -1) {
1981 remove_from_queue (bit, peer_element);
1984 new_deg = old_deg + bit->mode;
1986 GST_DEBUG_OBJECT (bit->bin,
1987 "change element %s, degree %d->%d, linked to %s",
1988 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1989 GST_ELEMENT_NAME (element));
1991 /* update degree, it is possible that an element was in 0 and
1992 * reaches -1 here. This would mean that the element had no sinkpads
1993 * but became linked while the state change was happening. We will
1994 * resync on this with the structure change message. */
1996 /* degree hit 0, add to queue */
1997 add_to_queue (bit, peer_element);
1999 HASH_SET_DEGREE (bit, peer_element, new_deg);
2003 GST_OBJECT_UNLOCK (peer_element);
2004 gst_object_unref (peer_element);
2006 gst_object_unref (peer);
2011 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
2012 GST_ELEMENT_NAME (element));
2014 GST_OBJECT_UNLOCK (element);
2017 /* find the next best element not handled yet. This is the one
2018 * with the lowest non-negative degree */
2020 find_element (GstElement * element, GstBinSortIterator * bit)
2024 /* element is already handled */
2025 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
2028 /* first element or element with smaller degree */
2029 if (bit->best == NULL || bit->best_deg > degree) {
2030 bit->best = element;
2031 bit->best_deg = degree;
2035 /* get next element in iterator. the returned element has the
2036 * refcount increased */
2037 static GstIteratorResult
2038 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2041 GstBin *bin = bit->bin;
2043 /* empty queue, we have to find a next best element */
2044 if (g_queue_is_empty (&bit->queue)) {
2046 bit->best_deg = G_MAXINT;
2047 g_list_foreach (bin->children, (GFunc) find_element, bit);
2048 if ((best = bit->best)) {
2049 /* when we detected an unlink, don't warn because our degrees might be
2050 * screwed up. We will resync later */
2051 if (bit->best_deg != 0 && !bit->dirty) {
2052 /* we don't fail on this one yet */
2053 GST_WARNING_OBJECT (bin, "loop dected in graph");
2054 g_warning ("loop detected in the graph of bin '%s'!!",
2055 GST_ELEMENT_NAME (bin));
2057 /* best unhandled element, schedule as next element */
2058 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2059 GST_ELEMENT_NAME (best));
2060 HASH_SET_DEGREE (bit, best, -1);
2061 g_value_set_object (result, best);
2063 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2064 /* no more unhandled elements, we are done */
2065 return GST_ITERATOR_DONE;
2068 /* everything added to the queue got reffed */
2069 best = g_queue_pop_head (&bit->queue);
2070 g_value_set_object (result, best);
2071 gst_object_unref (best);
2074 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2075 /* update degrees of linked elements */
2076 update_degree (best, bit);
2078 return GST_ITERATOR_OK;
2081 /* clear queues, recalculate the degrees and restart. */
2083 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2085 GstBin *bin = bit->bin;
2087 GST_DEBUG_OBJECT (bin, "resync");
2089 clear_queue (&bit->queue);
2091 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2092 /* calc degrees, incrementing */
2094 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2095 /* for the rest of the function we decrement the degrees */
2099 /* clear queues, unref bin and free iterator. */
2101 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2103 GstBin *bin = bit->bin;
2105 GST_DEBUG_OBJECT (bin, "free");
2106 clear_queue (&bit->queue);
2107 g_hash_table_destroy (bit->hash);
2108 gst_object_unref (bin);
2111 /* should be called with the bin LOCK held */
2112 static GstIterator *
2113 gst_bin_sort_iterator_new (GstBin * bin)
2115 GstBinSortIterator *result;
2117 /* we don't need an ItemFunction because we ref the items in the _next
2119 result = (GstBinSortIterator *)
2120 gst_iterator_new (sizeof (GstBinSortIterator),
2122 GST_OBJECT_GET_LOCK (bin),
2123 &bin->priv->structure_cookie,
2124 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2125 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2126 (GstIteratorItemFunction) NULL,
2127 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2128 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2129 g_queue_init (&result->queue);
2130 result->hash = g_hash_table_new (NULL, NULL);
2131 gst_object_ref (bin);
2133 gst_bin_sort_iterator_resync (result);
2135 return (GstIterator *) result;
2139 * gst_bin_iterate_sorted:
2142 * Gets an iterator for the elements in this bin in topologically
2143 * sorted order. This means that the elements are returned from
2144 * the most downstream elements (sinks) to the sources.
2146 * This function is used internally to perform the state changes
2147 * of the bin elements and for clock selection.
2149 * Each element yielded by the iterator will have its refcount increased, so
2152 * MT safe. Caller owns returned value.
2154 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2157 gst_bin_iterate_sorted (GstBin * bin)
2159 GstIterator *result;
2161 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2163 GST_OBJECT_LOCK (bin);
2164 result = gst_bin_sort_iterator_new (bin);
2165 GST_OBJECT_UNLOCK (bin);
2170 static GstStateChangeReturn
2171 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2172 GstClockTime base_time, GstClockTime start_time, GstState current,
2175 GstStateChangeReturn ret;
2176 GstState child_current, child_pending;
2180 GST_STATE_LOCK (element);
2182 GST_OBJECT_LOCK (element);
2183 /* set base_time and start time on child */
2184 GST_ELEMENT_START_TIME (element) = start_time;
2185 element->base_time = base_time;
2186 /* peel off the locked flag */
2187 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2188 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2189 ret = GST_STATE_RETURN (element);
2190 child_current = GST_STATE (element);
2191 child_pending = GST_STATE_PENDING (element);
2192 GST_OBJECT_UNLOCK (element);
2194 /* skip locked elements */
2195 if (G_UNLIKELY (locked))
2198 /* if the element was no preroll, just start changing the state regardless
2199 * if it had async elements (in the case of a bin) because they won't preroll
2201 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2202 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2206 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2207 "current %s pending %s, desired next %s",
2208 gst_element_state_get_name (child_current),
2209 gst_element_state_get_name (child_pending),
2210 gst_element_state_get_name (next));
2212 /* always recurse into bins so that we can set the base time */
2213 if (GST_IS_BIN (element))
2216 /* Try not to change the state of elements that are already in the state we're
2218 if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
2219 /* child is already at the requested state, return previous return. Note that
2220 * if the child has a pending state to next, we will still call the
2221 * set_state function */
2223 } else if (next > current) {
2224 /* upward state change */
2225 if (child_pending == GST_STATE_VOID_PENDING) {
2226 /* .. and the child is not busy doing anything */
2227 if (child_current > next) {
2228 /* .. and is already past the requested state, assume it got there
2230 ret = GST_STATE_CHANGE_SUCCESS;
2233 } else if (child_pending > child_current) {
2234 /* .. and the child is busy going upwards */
2235 if (child_current >= next) {
2236 /* .. and is already past the requested state, assume it got there
2238 ret = GST_STATE_CHANGE_SUCCESS;
2242 /* .. and the child is busy going downwards */
2243 if (child_current > next) {
2244 /* .. and is already past the requested state, assume it got there
2246 ret = GST_STATE_CHANGE_SUCCESS;
2250 } else if (next < current) {
2251 /* downward state change */
2252 if (child_pending == GST_STATE_VOID_PENDING) {
2253 /* .. and the child is not busy doing anything */
2254 if (child_current < next) {
2255 /* .. and is already past the requested state, assume it got there
2257 ret = GST_STATE_CHANGE_SUCCESS;
2260 } else if (child_pending < child_current) {
2261 /* .. and the child is busy going downwards */
2262 if (child_current <= next) {
2263 /* .. and is already past the requested state, assume it got there
2265 ret = GST_STATE_CHANGE_SUCCESS;
2269 /* .. and the child is busy going upwards */
2270 if (child_current < next) {
2271 /* .. and is already past the requested state, assume it got there
2273 ret = GST_STATE_CHANGE_SUCCESS;
2280 GST_OBJECT_LOCK (bin);
2281 /* the element was busy with an upwards async state change, we must wait for
2282 * an ASYNC_DONE message before we attemp to change the state. */
2284 find_message (bin, GST_OBJECT_CAST (element),
2285 GST_MESSAGE_ASYNC_START))) {
2286 #ifndef GST_DISABLE_GST_DEBUG
2287 GstMessage *message = GST_MESSAGE_CAST (found->data);
2289 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2290 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2292 /* only wait for upward state changes */
2293 if (next > current) {
2294 /* We found an async element check if we can force its state to change or
2295 * if we have to wait for it to preroll. */
2299 GST_OBJECT_UNLOCK (bin);
2302 GST_DEBUG_OBJECT (bin,
2303 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2304 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2305 GST_TIME_ARGS (base_time));
2308 ret = gst_element_set_state (element, next);
2310 GST_STATE_UNLOCK (element);
2316 GST_DEBUG_OBJECT (element,
2317 "element is locked, return previous return %s",
2318 gst_element_state_change_return_get_name (ret));
2319 GST_STATE_UNLOCK (element);
2324 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2325 "skipping transition from %s to %s",
2326 gst_element_state_get_name (child_current),
2327 gst_element_state_get_name (next));
2328 GST_STATE_UNLOCK (element);
2333 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2334 GST_OBJECT_UNLOCK (bin);
2335 GST_STATE_UNLOCK (element);
2336 return GST_STATE_CHANGE_ASYNC;
2340 /* gst_iterator_fold functions for pads_activate
2341 * Stop the iterator if activating one pad failed. */
2343 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2345 GstPad *pad = g_value_get_object (vpad);
2346 gboolean cont = TRUE;
2348 if (!(cont = gst_pad_set_active (pad, *active)))
2349 g_value_set_boolean (ret, FALSE);
2354 /* returns false on error or early cutout of the fold, true if all
2355 * pads in @iter were (de)activated successfully. */
2357 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2359 GstIteratorResult ires;
2362 /* no need to unset this later, it's just a boolean */
2363 g_value_init (&ret, G_TYPE_BOOLEAN);
2364 g_value_set_boolean (&ret, TRUE);
2367 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2370 case GST_ITERATOR_RESYNC:
2371 /* need to reset the result again */
2372 g_value_set_boolean (&ret, TRUE);
2373 gst_iterator_resync (iter);
2375 case GST_ITERATOR_DONE:
2376 /* all pads iterated, return collected value */
2379 /* iterator returned _ERROR or premature end with _OK,
2380 * mark an error and exit */
2381 g_value_set_boolean (&ret, FALSE);
2386 /* return collected value */
2387 return g_value_get_boolean (&ret);
2390 /* is called with STATE_LOCK
2393 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2398 GST_DEBUG_OBJECT (bin, "%s pads", active ? "activate" : "deactivate");
2400 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2401 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2402 gst_iterator_free (iter);
2403 if (G_UNLIKELY (!fold_ok))
2406 GST_DEBUG_OBJECT (bin, "pad %sactivation successful", active ? "" : "de");
2413 GST_DEBUG_OBJECT (bin, "pad %sactivation failed", active ? "" : "de");
2419 * gst_bin_recalculate_latency:
2422 * Query @bin for the current latency using and reconfigures this latency to all the
2423 * elements with a LATENCY event.
2425 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2426 * is posted on the bus.
2428 * This function simply emits the 'do-latency' signal so any custom latency
2429 * calculations will be performed.
2431 * Returns: %TRUE if the latency could be queried and reconfigured.
2434 gst_bin_recalculate_latency (GstBin * bin)
2438 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2439 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2445 gst_bin_do_latency_func (GstBin * bin)
2448 GstElement *element;
2449 GstClockTime min_latency, max_latency;
2452 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2454 element = GST_ELEMENT_CAST (bin);
2456 GST_DEBUG_OBJECT (element, "querying latency");
2458 query = gst_query_new_latency ();
2459 if ((res = gst_element_query (element, query))) {
2462 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2464 GST_DEBUG_OBJECT (element,
2465 "got min latency %" GST_TIME_FORMAT ", max latency %"
2466 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2467 GST_TIME_ARGS (max_latency), live);
2469 if (max_latency < min_latency) {
2470 /* this is an impossible situation, some parts of the pipeline might not
2471 * work correctly. We post a warning for now. */
2472 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2473 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2474 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2475 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2478 /* configure latency on elements */
2479 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2481 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2482 GST_TIME_ARGS (min_latency));
2484 GST_WARNING_OBJECT (element,
2485 "did not really configure latency of %" GST_TIME_FORMAT,
2486 GST_TIME_ARGS (min_latency));
2489 /* this is not a real problem, we just don't configure any latency. */
2490 GST_WARNING_OBJECT (element, "failed to query latency");
2492 gst_query_unref (query);
2498 gst_bin_state_changed (GstElement * element, GstState oldstate,
2499 GstState newstate, GstState pending)
2501 GstElementClass *pklass = (GstElementClass *) parent_class;
2503 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2504 bin_do_eos (GST_BIN_CAST (element));
2506 if (pklass->state_changed)
2507 pklass->state_changed (element, oldstate, newstate, pending);
2510 static GstStateChangeReturn
2511 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2514 GstStateChangeReturn ret;
2515 GstState current, next;
2516 gboolean have_async;
2517 gboolean have_no_preroll;
2518 GstClockTime base_time, start_time;
2521 GValue data = { 0, };
2523 /* we don't need to take the STATE_LOCK, it is already taken */
2524 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2525 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2527 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2528 "changing state of children from %s to %s",
2529 gst_element_state_get_name (current), gst_element_state_get_name (next));
2531 bin = GST_BIN_CAST (element);
2534 case GST_STATE_PLAYING:
2538 GST_OBJECT_LOCK (bin);
2539 toplevel = BIN_IS_TOPLEVEL (bin);
2540 GST_OBJECT_UNLOCK (bin);
2543 gst_bin_recalculate_latency (bin);
2546 case GST_STATE_PAUSED:
2547 /* Clear EOS list on next PAUSED */
2548 GST_OBJECT_LOCK (bin);
2549 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2550 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2551 bin->priv->posted_eos = FALSE;
2552 if (current == GST_STATE_READY)
2553 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
2554 GST_OBJECT_UNLOCK (bin);
2555 if (current == GST_STATE_READY)
2556 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2557 goto activate_failure;
2559 case GST_STATE_READY:
2560 /* Clear message list on next READY */
2561 GST_OBJECT_LOCK (bin);
2562 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2563 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2564 GST_OBJECT_UNLOCK (bin);
2565 if (current == GST_STATE_PAUSED)
2566 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2567 goto activate_failure;
2569 case GST_STATE_NULL:
2570 if (current == GST_STATE_READY)
2571 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2572 goto activate_failure;
2578 /* this flag is used to make the async state changes return immediately. We
2579 * don't want them to interfere with this state change */
2580 GST_OBJECT_LOCK (bin);
2581 bin->polling = TRUE;
2582 GST_OBJECT_UNLOCK (bin);
2584 /* iterate in state change order */
2585 it = gst_bin_iterate_sorted (bin);
2587 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2588 * Note how we don't reset this value when a resync happens, the reason being
2589 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2590 * even after a resync when the async element is gone */
2594 /* take base_time */
2595 base_time = gst_element_get_base_time (element);
2596 start_time = gst_element_get_start_time (element);
2598 have_no_preroll = FALSE;
2602 switch (gst_iterator_next (it, &data)) {
2603 case GST_ITERATOR_OK:
2607 child = g_value_get_object (&data);
2609 /* set state and base_time now */
2610 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2614 case GST_STATE_CHANGE_SUCCESS:
2615 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2616 "child '%s' changed state to %d(%s) successfully",
2617 GST_ELEMENT_NAME (child), next,
2618 gst_element_state_get_name (next));
2620 case GST_STATE_CHANGE_ASYNC:
2622 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2623 "child '%s' is changing state asynchronously to %s",
2624 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2628 case GST_STATE_CHANGE_FAILURE:{
2631 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2632 "child '%s' failed to go to state %d(%s)",
2633 GST_ELEMENT_NAME (child),
2634 next, gst_element_state_get_name (next));
2636 /* Only fail if the child is still inside
2637 * this bin. It might've been removed already
2638 * because of the error by the bin subclass
2639 * to ignore the error. */
2640 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2641 if (parent == GST_OBJECT_CAST (element)) {
2642 /* element is still in bin, really error now */
2643 gst_object_unref (parent);
2646 /* child removed from bin, let the resync code redo the state
2648 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2649 "child '%s' was removed from the bin",
2650 GST_ELEMENT_NAME (child));
2653 gst_object_unref (parent);
2657 case GST_STATE_CHANGE_NO_PREROLL:
2658 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2659 "child '%s' changed state to %d(%s) successfully without preroll",
2660 GST_ELEMENT_NAME (child), next,
2661 gst_element_state_get_name (next));
2662 have_no_preroll = TRUE;
2665 g_assert_not_reached ();
2668 g_value_reset (&data);
2671 case GST_ITERATOR_RESYNC:
2672 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2673 gst_iterator_resync (it);
2676 case GST_ITERATOR_DONE:
2677 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2683 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2684 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2687 if (have_no_preroll) {
2688 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2689 "we have NO_PREROLL elements %s -> NO_PREROLL",
2690 gst_element_state_change_return_get_name (ret));
2691 ret = GST_STATE_CHANGE_NO_PREROLL;
2692 } else if (have_async) {
2693 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2694 "we have ASYNC elements %s -> ASYNC",
2695 gst_element_state_change_return_get_name (ret));
2696 ret = GST_STATE_CHANGE_ASYNC;
2700 g_value_unset (&data);
2701 gst_iterator_free (it);
2703 GST_OBJECT_LOCK (bin);
2704 bin->polling = FALSE;
2705 /* it's possible that we did not get ASYNC from the children while the bin is
2706 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2707 * itself as the source. In that case we still want to check if the state
2708 * change completed. */
2709 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2710 /* no element returned ASYNC and there are no pending async_done messages,
2711 * we can just complete. */
2712 GST_DEBUG_OBJECT (bin, "no async elements");
2715 /* when we get here an ASYNC element was found */
2716 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2717 /* we ignore ASYNC state changes when we go to READY or NULL */
2718 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2719 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2723 GST_DEBUG_OBJECT (bin, "check async elements");
2724 /* check if all elements managed to commit their state already */
2725 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2726 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2727 * all the elements commited their state while we were doing the state
2728 * change. We will still return ASYNC for consistency but we commit the
2729 * state already so that a _get_state() will return immediately. */
2730 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2732 GST_DEBUG_OBJECT (bin, "async elements commited");
2733 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
2734 GST_CLOCK_TIME_NONE);
2738 bin->priv->pending_async_done = FALSE;
2739 GST_OBJECT_UNLOCK (bin);
2741 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2742 "done changing bin's state from %s to %s, now in %s, ret %s",
2743 gst_element_state_get_name (current),
2744 gst_element_state_get_name (next),
2745 gst_element_state_get_name (GST_STATE (element)),
2746 gst_element_state_change_return_get_name (ret));
2753 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2754 "failure (de)activating src pads");
2755 return GST_STATE_CHANGE_FAILURE;
2760 * This function is a utility event handler for seek events.
2761 * It will send the event to all sinks or sources depending on the
2764 * Applications are free to override this behaviour and
2765 * implement their own seek handler, but this will work for
2766 * pretty much all cases in practice.
2769 gst_bin_send_event (GstElement * element, GstEvent * event)
2771 GstBin *bin = GST_BIN_CAST (element);
2773 gboolean res = TRUE;
2774 gboolean done = FALSE;
2775 GValue data = { 0, };
2777 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2778 iter = gst_bin_iterate_sources (bin);
2779 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2780 GST_EVENT_TYPE_NAME (event));
2782 iter = gst_bin_iterate_sinks (bin);
2783 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2784 GST_EVENT_TYPE_NAME (event));
2788 switch (gst_iterator_next (iter, &data)) {
2789 case GST_ITERATOR_OK:
2791 GstElement *child = g_value_get_object (&data);;
2793 gst_event_ref (event);
2794 res &= gst_element_send_event (child, event);
2796 GST_LOG_OBJECT (child, "After handling %s event: %d",
2797 GST_EVENT_TYPE_NAME (event), res);
2799 g_value_reset (&data);
2802 case GST_ITERATOR_RESYNC:
2803 gst_iterator_resync (iter);
2806 case GST_ITERATOR_DONE:
2809 case GST_ITERATOR_ERROR:
2810 g_assert_not_reached ();
2814 g_value_unset (&data);
2815 gst_iterator_free (iter);
2816 gst_event_unref (event);
2821 /* this is the function called by the threadpool. When async elements commit
2822 * their state, this function will attempt to bring the bin to the next state.
2825 gst_bin_continue_func (BinContinueData * data)
2828 GstState current, next, pending;
2829 GstStateChange transition;
2832 pending = data->pending;
2834 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2835 GST_STATE_LOCK (bin);
2837 GST_DEBUG_OBJECT (bin, "doing state continue");
2838 GST_OBJECT_LOCK (bin);
2840 /* if a new state change happened after this thread was scheduled, we return
2842 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2845 current = GST_STATE (bin);
2846 next = GST_STATE_GET_NEXT (current, pending);
2847 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2849 GST_STATE_NEXT (bin) = next;
2850 GST_STATE_PENDING (bin) = pending;
2852 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2853 GST_OBJECT_UNLOCK (bin);
2855 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2856 "continue state change %s to %s, final %s",
2857 gst_element_state_get_name (current),
2858 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2860 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2862 GST_STATE_UNLOCK (bin);
2863 GST_DEBUG_OBJECT (bin, "state continue done");
2865 gst_object_unref (bin);
2866 g_slice_free (BinContinueData, data);
2871 GST_OBJECT_UNLOCK (bin);
2872 GST_STATE_UNLOCK (bin);
2873 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2874 gst_object_unref (bin);
2875 g_slice_free (BinContinueData, data);
2880 static GstBusSyncReply
2881 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2883 GstBinClass *bclass;
2885 bclass = GST_BIN_GET_CLASS (bin);
2886 if (bclass->handle_message)
2887 bclass->handle_message (bin, message);
2889 gst_message_unref (message);
2891 return GST_BUS_DROP;
2895 bin_push_state_continue (BinContinueData * data)
2902 klass = GST_BIN_GET_CLASS (bin);
2904 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2905 g_thread_pool_push (klass->pool, data, NULL);
2908 /* an element started an async state change, if we were not busy with a state
2909 * change, we perform a lost state.
2910 * This function is called with the OBJECT lock.
2913 bin_handle_async_start (GstBin * bin)
2915 GstState old_state, new_state;
2917 GstMessage *amessage = NULL;
2919 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2922 /* get our toplevel state */
2923 toplevel = BIN_IS_TOPLEVEL (bin);
2925 /* prepare an ASYNC_START message, we always post the start message even if we
2926 * are busy with a state change or when we are NO_PREROLL. */
2928 /* non toplevel bin, prepare async-start for the parent */
2929 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
2931 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2934 /* async starts are ignored when we are NO_PREROLL */
2935 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2936 goto was_no_preroll;
2938 old_state = GST_STATE (bin);
2940 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2941 * PLAYING after optionally redistributing the base_time. */
2942 if (old_state > GST_STATE_PAUSED)
2943 new_state = GST_STATE_PAUSED;
2945 new_state = old_state;
2947 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2948 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2949 gst_element_state_get_name (new_state));
2951 GST_STATE (bin) = new_state;
2952 GST_STATE_NEXT (bin) = new_state;
2953 GST_STATE_PENDING (bin) = new_state;
2954 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2955 GST_OBJECT_UNLOCK (bin);
2958 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2963 /* post our ASYNC_START. */
2964 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2965 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2967 GST_OBJECT_LOCK (bin);
2973 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2978 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2979 GST_OBJECT_UNLOCK (bin);
2984 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2985 GST_OBJECT_UNLOCK (bin);
2990 /* this function is called when there are no more async elements in the bin. We
2991 * post a state changed message and an ASYNC_DONE message.
2992 * This function is called with the OBJECT lock.
2995 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2996 gboolean flag_pending, GstClockTime running_time)
2998 GstState current, pending, target;
2999 GstStateChangeReturn old_ret;
3000 GstState old_state, old_next;
3001 gboolean toplevel, state_changed = FALSE;
3002 GstMessage *amessage = NULL;
3003 BinContinueData *cont = NULL;
3005 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
3008 pending = GST_STATE_PENDING (bin);
3013 /* check if there is something to commit */
3014 if (pending == GST_STATE_VOID_PENDING)
3015 goto nothing_pending;
3017 old_ret = GST_STATE_RETURN (bin);
3018 GST_STATE_RETURN (bin) = ret;
3020 /* move to the next target state */
3021 target = GST_STATE_TARGET (bin);
3022 pending = GST_STATE_PENDING (bin) = target;
3024 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
3026 old_state = GST_STATE (bin);
3027 /* this is the state we should go to next */
3028 old_next = GST_STATE_NEXT (bin);
3030 if (old_next != GST_STATE_PLAYING) {
3031 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3032 "committing state from %s to %s, old pending %s",
3033 gst_element_state_get_name (old_state),
3034 gst_element_state_get_name (old_next),
3035 gst_element_state_get_name (pending));
3037 /* update current state */
3038 current = GST_STATE (bin) = old_next;
3040 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3041 "setting state from %s to %s, pending %s",
3042 gst_element_state_get_name (old_state),
3043 gst_element_state_get_name (old_state),
3044 gst_element_state_get_name (pending));
3045 current = old_state;
3048 /* get our toplevel state */
3049 toplevel = BIN_IS_TOPLEVEL (bin);
3051 /* see if we reached the final state. If we are not toplevel, we also have to
3052 * stop here, the parent will continue our state. */
3053 if ((pending == current) || !toplevel) {
3054 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3055 "completed state change, pending VOID");
3057 /* mark VOID pending */
3058 pending = GST_STATE_VOID_PENDING;
3059 GST_STATE_PENDING (bin) = pending;
3060 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
3062 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
3063 "continue state change, pending %s",
3064 gst_element_state_get_name (pending));
3066 cont = g_slice_new (BinContinueData);
3068 /* ref to the bin */
3069 cont->bin = gst_object_ref (bin);
3070 /* cookie to detect concurrent state change */
3071 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3072 /* pending target state */
3073 cont->pending = pending;
3075 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3076 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3079 if (old_next != GST_STATE_PLAYING) {
3080 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3081 state_changed = TRUE;
3084 GST_OBJECT_UNLOCK (bin);
3086 if (state_changed) {
3087 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3091 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3092 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3093 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3096 GST_OBJECT_LOCK (bin);
3098 /* toplevel, start continue state */
3099 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3100 bin_push_state_continue (cont);
3102 GST_DEBUG_OBJECT (bin, "state change complete");
3103 GST_STATE_BROADCAST (bin);
3109 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3114 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3115 /* if we were busy with a state change and we are requested to flag a
3116 * pending async done, we do so here */
3118 bin->priv->pending_async_done = TRUE;
3123 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3129 bin_do_eos (GstBin * bin)
3134 GST_OBJECT_LOCK (bin);
3135 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3136 * we forward the EOS message to the parent bin or application
3138 eos = GST_STATE (bin) == GST_STATE_PLAYING
3139 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3140 && is_eos (bin, &seqnum);
3141 GST_OBJECT_UNLOCK (bin);
3144 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3146 GstMessage *tmessage;
3148 /* Clear out any further messages, and reset posted_eos so we can
3149 detect any new EOS that happens (eg, after a seek). Since all
3150 sinks have now posted an EOS, there will be no further EOS events
3151 seen unless there is a new logical EOS */
3152 GST_OBJECT_LOCK (bin);
3153 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3154 bin->priv->posted_eos = FALSE;
3155 GST_OBJECT_UNLOCK (bin);
3157 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3158 gst_message_set_seqnum (tmessage, seqnum);
3159 GST_DEBUG_OBJECT (bin,
3160 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3161 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3166 bin_do_stream_start (GstBin * bin)
3169 gboolean stream_start;
3171 GST_OBJECT_LOCK (bin);
3172 /* If all sinks are STREAM_START we forward the STREAM_START message
3173 * to the parent bin or application
3175 stream_start = is_stream_start (bin, &seqnum);
3176 GST_OBJECT_UNLOCK (bin);
3179 GstMessage *tmessage;
3181 GST_OBJECT_LOCK (bin);
3182 bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
3183 GST_OBJECT_UNLOCK (bin);
3185 tmessage = gst_message_new_stream_start (GST_OBJECT_CAST (bin));
3186 gst_message_set_seqnum (tmessage, seqnum);
3187 GST_DEBUG_OBJECT (bin,
3188 "all sinks posted STREAM_START, posting seqnum #%" G_GUINT32_FORMAT,
3190 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3194 /* must be called with the object lock. This function releases the lock to post
3197 bin_do_message_forward (GstBin * bin, GstMessage * message)
3199 if (bin->priv->message_forward) {
3200 GstMessage *forwarded;
3202 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3203 GST_MESSAGE_TYPE_NAME (message));
3204 GST_OBJECT_UNLOCK (bin);
3206 /* we need to convert these messages to element messages so that our parent
3207 * bin can easily ignore them and so that the application can easily
3208 * distinguish between the internally forwarded and the real messages. */
3209 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3210 gst_structure_new ("GstBinForwarded",
3211 "message", GST_TYPE_MESSAGE, message, NULL));
3213 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3215 GST_OBJECT_LOCK (bin);
3219 /* handle child messages:
3221 * This method is called synchronously when a child posts a message on
3224 * GST_MESSAGE_EOS: This message is only posted by sinks
3225 * in the PLAYING state. If all sinks posted the EOS message, post
3228 * GST_MESSAGE_STATE_DIRTY: Deprecated
3230 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3231 * element posts segment_start twice, only the last message is kept.
3233 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3234 * with the segment_done message. If there are no more segment_start
3235 * messages, post segment_done message upwards.
3237 * GST_MESSAGE_DURATION_CHANGED: clear any cached durations.
3238 * Whenever someone performs a duration query on the bin, we store the
3239 * result so we can answer it quicker the next time. Any element that
3240 * changes its duration marks our cached values invalid.
3241 * This message is also posted upwards. This is currently disabled
3242 * because too many elements don't post DURATION messages when the
3245 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3246 * can no longer provide a clock. The default bin behaviour is to
3247 * check if the lost clock was the one provided by the bin. If so and
3248 * we are currently in the PLAYING state, we forward the message to
3250 * This message is also generated when we remove a clock provider from
3251 * a bin. If this message is received by the application, it should
3252 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3253 * and a new base_time distribution.
3255 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3256 * can provide a clock. This mostly happens when we add a new clock
3257 * provider to the bin. The default behaviour of the bin is to mark the
3258 * currently selected clock as dirty, which will perform a clock
3259 * recalculation the next time we are asked to provide a clock.
3260 * This message is never sent to the application but is forwarded to
3263 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3264 * the state of the element and the fact that the element will need a
3265 * new base_time. This message is not forwarded to the application.
3267 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3268 * element when it posted ASYNC_START. If all elements are done, post a
3269 * ASYNC_DONE message to the parent.
3271 * OTHER: post upwards.
3274 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3277 GstMessageType type;
3278 GstMessage *tmessage;
3281 src = GST_MESSAGE_SRC (message);
3282 type = GST_MESSAGE_TYPE (message);
3284 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3285 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3286 GST_MESSAGE_TYPE_NAME (message));
3289 case GST_MESSAGE_ERROR:
3291 GST_OBJECT_LOCK (bin);
3293 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3294 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3295 GST_STATE_BROADCAST (bin);
3296 GST_OBJECT_UNLOCK (bin);
3300 case GST_MESSAGE_EOS:
3303 /* collect all eos messages from the children */
3304 GST_OBJECT_LOCK (bin);
3305 bin_do_message_forward (bin, message);
3306 /* ref message for future use */
3307 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3308 GST_OBJECT_UNLOCK (bin);
3313 case GST_MESSAGE_STREAM_START:
3316 /* collect all stream_start messages from the children */
3317 GST_OBJECT_LOCK (bin);
3318 /* ref message for future use */
3319 bin_replace_message (bin, message, GST_MESSAGE_STREAM_START);
3320 GST_OBJECT_UNLOCK (bin);
3322 bin_do_stream_start (bin);
3325 case GST_MESSAGE_STATE_DIRTY:
3327 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3330 gst_message_unref (message);
3333 case GST_MESSAGE_SEGMENT_START:{
3334 gboolean post = FALSE;
3338 gst_message_parse_segment_start (message, &format, &position);
3339 seqnum = gst_message_get_seqnum (message);
3341 GST_OBJECT_LOCK (bin);
3342 bin_do_message_forward (bin, message);
3343 /* if this is the first segment-start, post to parent but not to the
3345 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3346 (GST_OBJECT_PARENT (bin) != NULL)) {
3349 /* replace any previous segment_start message from this source
3350 * with the new segment start message */
3351 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3352 GST_OBJECT_UNLOCK (bin);
3354 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3356 gst_message_set_seqnum (tmessage, seqnum);
3358 /* post segment start with initial format and position. */
3359 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3361 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3365 case GST_MESSAGE_SEGMENT_DONE:
3367 gboolean post = FALSE;
3371 gst_message_parse_segment_done (message, &format, &position);
3372 seqnum = gst_message_get_seqnum (message);
3374 GST_OBJECT_LOCK (bin);
3375 bin_do_message_forward (bin, message);
3376 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3377 /* if there are no more segment_start messages, everybody posted
3378 * a segment_done and we can post one on the bus. */
3380 /* we don't care who still has a pending segment start */
3381 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3384 /* remove all old segment_done messages */
3385 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3387 GST_OBJECT_UNLOCK (bin);
3389 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3391 gst_message_set_seqnum (tmessage, seqnum);
3393 /* post segment done with latest format and position. */
3394 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3396 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3400 case GST_MESSAGE_DURATION_CHANGED:
3402 /* FIXME: remove all cached durations, next time somebody asks
3403 * for duration, we will recalculate. */
3405 GST_OBJECT_LOCK (bin);
3406 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3407 GST_OBJECT_UNLOCK (bin);
3411 case GST_MESSAGE_CLOCK_LOST:
3413 GstClock **provided_clock_p;
3414 GstElement **clock_provider_p;
3415 gboolean playing, provided, forward;
3418 gst_message_parse_clock_lost (message, &clock);
3420 GST_OBJECT_LOCK (bin);
3421 bin->clock_dirty = TRUE;
3422 /* if we lost the clock that we provided, post to parent but
3423 * only if we are PLAYING. */
3424 provided = (clock == bin->provided_clock);
3425 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3426 forward = playing & provided;
3428 GST_DEBUG_OBJECT (bin,
3429 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3430 bin->provided_clock, bin->clock_provider);
3431 provided_clock_p = &bin->provided_clock;
3432 clock_provider_p = &bin->clock_provider;
3433 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3434 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3436 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3437 provided, playing, forward);
3438 GST_OBJECT_UNLOCK (bin);
3444 gst_message_unref (message);
3447 case GST_MESSAGE_CLOCK_PROVIDE:
3451 GST_OBJECT_LOCK (bin);
3452 bin->clock_dirty = TRUE;
3453 /* a new clock is available, post to parent but not
3454 * to the application */
3455 forward = GST_OBJECT_PARENT (bin) != NULL;
3456 GST_OBJECT_UNLOCK (bin);
3462 gst_message_unref (message);
3465 case GST_MESSAGE_ASYNC_START:
3469 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3470 src ? GST_OBJECT_NAME (src) : "(NULL)");
3472 GST_OBJECT_LOCK (bin);
3473 bin_do_message_forward (bin, message);
3475 /* we ignore the message if we are going to <= READY */
3476 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3477 goto ignore_start_message;
3479 /* takes ownership of the message */
3480 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3482 bin_handle_async_start (bin);
3483 GST_OBJECT_UNLOCK (bin);
3486 ignore_start_message:
3488 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3489 gst_element_state_get_name (target));
3490 GST_OBJECT_UNLOCK (bin);
3491 gst_message_unref (message);
3495 case GST_MESSAGE_ASYNC_DONE:
3497 GstClockTime running_time;
3500 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3501 src ? GST_OBJECT_NAME (src) : "(NULL)");
3503 gst_message_parse_async_done (message, &running_time);
3505 GST_OBJECT_LOCK (bin);
3506 bin_do_message_forward (bin, message);
3508 /* ignore messages if we are shutting down */
3509 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3510 goto ignore_done_message;
3512 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3513 /* if there are no more ASYNC_START messages, everybody posted
3514 * a ASYNC_DONE and we can post one on the bus. When checking, we
3515 * don't care who still has a pending ASYNC_START */
3516 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3517 /* nothing found, remove all old ASYNC_DONE messages */
3518 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3520 GST_DEBUG_OBJECT (bin, "async elements commited");
3521 /* when we get an async done message when a state change was busy, we
3522 * need to set the pending_done flag so that at the end of the state
3523 * change we can see if we need to verify pending async elements, hence
3524 * the TRUE argument here. */
3525 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
3528 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3530 GST_OBJECT_UNLOCK (bin);
3533 ignore_done_message:
3535 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3536 gst_element_state_get_name (target));
3537 GST_OBJECT_UNLOCK (bin);
3538 gst_message_unref (message);
3542 case GST_MESSAGE_STRUCTURE_CHANGE:
3546 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3548 GST_OBJECT_LOCK (bin);
3550 /* while the pad is busy, avoid following it when doing state changes.
3551 * Don't update the cookie yet, we will do that after the structure
3552 * change finished and we are ready to inspect the new updated
3554 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3557 /* a pad link/unlink ended, signal the state change iterator that we
3558 * need to resync by updating the structure_cookie. */
3559 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3560 GST_MESSAGE_STRUCTURE_CHANGE);
3561 if (!GST_BIN_IS_NO_RESYNC (bin))
3562 bin->priv->structure_cookie++;
3564 GST_OBJECT_UNLOCK (bin);
3567 gst_message_unref (message);
3578 /* Send all other messages upward */
3579 GST_DEBUG_OBJECT (bin, "posting message upward");
3580 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3585 /* generic struct passed to all query fold methods */
3594 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3595 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3597 /* for duration/position we collect all durations/positions and take
3598 * the MAX of all valid results */
3600 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3608 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3610 GstElement *item = g_value_get_object (vitem);
3612 if (gst_element_query (item, fold->query)) {
3615 g_value_set_boolean (ret, TRUE);
3617 gst_query_parse_duration (fold->query, NULL, &duration);
3619 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3621 if (duration == -1) {
3622 /* duration query succeeded, but duration is unknown */
3627 if (duration > fold->max)
3628 fold->max = duration;
3635 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3639 gst_query_parse_duration (fold->query, &format, NULL);
3640 /* store max in query result */
3641 gst_query_set_duration (fold->query, format, fold->max);
3643 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3645 /* FIXME: re-implement duration caching */
3648 GST_OBJECT_LOCK (bin);
3649 bin->messages = g_list_prepend (bin->messages,
3650 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3651 GST_OBJECT_UNLOCK (bin);
3656 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3658 GstElement *item = g_value_get_object (vitem);
3660 if (gst_element_query (item, fold->query)) {
3663 g_value_set_boolean (ret, TRUE);
3665 gst_query_parse_position (fold->query, NULL, &position);
3667 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3669 if (position > fold->max)
3670 fold->max = position;
3677 bin_query_position_done (GstBin * bin, QueryFold * fold)
3681 gst_query_parse_position (fold->query, &format, NULL);
3682 /* store max in query result */
3683 gst_query_set_position (fold->query, format, fold->max);
3685 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3689 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3691 GstElement *item = g_value_get_object (vitem);
3693 if (gst_element_query (item, fold->query)) {
3694 GstClockTime min, max;
3697 gst_query_parse_latency (fold->query, &live, &min, &max);
3699 GST_DEBUG_OBJECT (item,
3700 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3701 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3703 /* for the combined latency we collect the MAX of all min latencies and
3704 * the MIN of all max latencies */
3706 if (min > fold->min)
3708 if (fold->max == -1)
3710 else if (max < fold->max)
3712 if (fold->live == FALSE)
3716 g_value_set_boolean (ret, FALSE);
3717 GST_DEBUG_OBJECT (item, "failed query");
3724 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3726 /* store max in query result */
3727 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3729 GST_DEBUG_OBJECT (bin,
3730 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3731 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3735 /* generic fold, return first valid result */
3737 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3739 GstElement *item = g_value_get_object (vitem);
3742 if ((res = gst_element_query (item, fold->query))) {
3743 g_value_set_boolean (ret, TRUE);
3744 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3747 /* and stop as soon as we have a valid result */
3752 gst_bin_query (GstElement * element, GstQuery * query)
3754 GstBin *bin = GST_BIN_CAST (element);
3756 gboolean res = FALSE;
3757 GstIteratorFoldFunction fold_func;
3758 QueryInitFunction fold_init = NULL;
3759 QueryDoneFunction fold_done = NULL;
3760 QueryFold fold_data;
3763 switch (GST_QUERY_TYPE (query)) {
3764 case GST_QUERY_DURATION:
3766 /* FIXME: implement duration caching in GstBin again */
3771 gst_query_parse_duration (query, &qformat, NULL);
3773 /* find cached duration query */
3774 GST_OBJECT_LOCK (bin);
3775 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3776 GstMessage *message = (GstMessage *) cached->data;
3778 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3779 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3783 gst_message_parse_duration (message, &format, &duration);
3785 /* if cached same format, copy duration in query result */
3786 if (format == qformat) {
3787 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3789 GST_OBJECT_UNLOCK (bin);
3791 gst_query_set_duration (query, qformat, duration);
3797 GST_OBJECT_UNLOCK (bin);
3799 GST_FIXME ("implement duration caching in GstBin again");
3801 /* no cached value found, iterate and collect durations */
3802 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3803 fold_init = bin_query_min_max_init;
3804 fold_done = bin_query_duration_done;
3807 case GST_QUERY_POSITION:
3809 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3810 fold_init = bin_query_min_max_init;
3811 fold_done = bin_query_position_done;
3814 case GST_QUERY_LATENCY:
3816 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3817 fold_init = bin_query_min_max_init;
3818 fold_done = bin_query_latency_done;
3823 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3827 fold_data.query = query;
3829 /* set the result of the query to FALSE initially */
3830 g_value_init (&ret, G_TYPE_BOOLEAN);
3831 g_value_set_boolean (&ret, res);
3833 iter = gst_bin_iterate_sinks (bin);
3834 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3835 query, GST_QUERY_TYPE_NAME (query));
3838 fold_init (bin, &fold_data);
3841 GstIteratorResult ires;
3843 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3846 case GST_ITERATOR_RESYNC:
3847 gst_iterator_resync (iter);
3849 fold_init (bin, &fold_data);
3850 g_value_set_boolean (&ret, res);
3852 case GST_ITERATOR_OK:
3853 case GST_ITERATOR_DONE:
3854 res = g_value_get_boolean (&ret);
3855 if (fold_done != NULL && res)
3856 fold_done (bin, &fold_data);
3864 gst_iterator_free (iter);
3866 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3872 compare_name (const GValue * velement, const gchar * name)
3875 GstElement *element = g_value_get_object (velement);
3877 GST_OBJECT_LOCK (element);
3878 eq = strcmp (GST_ELEMENT_NAME (element), name);
3879 GST_OBJECT_UNLOCK (element);
3885 * gst_bin_get_by_name:
3887 * @name: the element name to search for
3889 * Gets the element with the given name from a bin. This
3890 * function recurses into child bins.
3892 * Returns NULL if no element with the given name is found in the bin.
3894 * MT safe. Caller owns returned reference.
3896 * Returns: (transfer full): the #GstElement with the given name, or NULL
3899 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3901 GstIterator *children;
3902 GValue result = { 0, };
3903 GstElement *element;
3906 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3908 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3909 GST_ELEMENT_NAME (bin), name);
3911 children = gst_bin_iterate_recurse (bin);
3912 found = gst_iterator_find_custom (children,
3913 (GCompareFunc) compare_name, &result, (gpointer) name);
3914 gst_iterator_free (children);
3917 element = g_value_dup_object (&result);
3918 g_value_unset (&result);
3927 * gst_bin_get_by_name_recurse_up:
3929 * @name: the element name to search for
3931 * Gets the element with the given name from this bin. If the
3932 * element is not found, a recursion is performed on the parent bin.
3935 * - no element with the given name is found in the bin
3937 * MT safe. Caller owns returned reference.
3939 * Returns: (transfer full): the #GstElement with the given name, or NULL
3942 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3946 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3947 g_return_val_if_fail (name != NULL, NULL);
3949 result = gst_bin_get_by_name (bin, name);
3954 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3956 if (GST_IS_BIN (parent)) {
3957 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3959 gst_object_unref (parent);
3967 compare_interface (const GValue * velement, GValue * interface)
3969 GstElement *element = g_value_get_object (velement);
3970 GType interface_type = (GType) g_value_get_pointer (interface);
3973 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3982 * gst_bin_get_by_interface:
3984 * @iface: the #GType of an interface
3986 * Looks for an element inside the bin that implements the given
3987 * interface. If such an element is found, it returns the element.
3988 * You can cast this element to the given interface afterwards. If you want
3989 * all elements that implement the interface, use
3990 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3992 * MT safe. Caller owns returned reference.
3994 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3997 gst_bin_get_by_interface (GstBin * bin, GType iface)
3999 GstIterator *children;
4000 GValue result = { 0, };
4001 GstElement *element;
4003 GValue viface = { 0, };
4005 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4006 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4008 g_value_init (&viface, G_TYPE_POINTER);
4009 g_value_set_pointer (&viface, (gpointer) iface);
4011 children = gst_bin_iterate_recurse (bin);
4012 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
4014 gst_iterator_free (children);
4017 element = g_value_dup_object (&result);
4018 g_value_unset (&result);
4022 g_value_unset (&viface);
4028 * gst_bin_iterate_all_by_interface:
4030 * @iface: the #GType of an interface
4032 * Looks for all elements inside the bin that implements the given
4033 * interface. You can safely cast all returned elements to the given interface.
4034 * The function recurses inside child bins. The iterator will yield a series
4035 * of #GstElement that should be unreffed after use.
4037 * Each element yielded by the iterator will have its refcount increased, so
4040 * MT safe. Caller owns returned value.
4042 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
4043 * in the bin implementing the given interface, or NULL
4046 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
4048 GstIterator *children;
4049 GstIterator *result;
4050 GValue viface = { 0, };
4052 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
4053 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
4055 g_value_init (&viface, G_TYPE_POINTER);
4056 g_value_set_pointer (&viface, (gpointer) iface);
4058 children = gst_bin_iterate_recurse (bin);
4059 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
4062 g_value_unset (&viface);