3 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
4 * 2004 Wim Taymans <wim.taymans@gmail.com>
6 * gstbin.c: GstBin container object and support code
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
28 * @short_description: Base class and element that can contain other elements
30 * #GstBin is an element that can contain other #GstElement, allowing them to be
32 * Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
33 * This makes the bin look like any other elements and enables creation of
34 * higher-level abstraction elements.
36 * A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
37 * want to create a toplevel bin because a normal bin doesn't have a bus or
38 * handle clock distribution of its own.
40 * After the bin has been created you will typically add elements to it with
41 * gst_bin_add(). You can remove elements with gst_bin_remove().
43 * An element can be retrieved from a bin with gst_bin_get_by_name(), using the
44 * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
45 * purposes and will query the parent bins when the element is not found in the
48 * An iterator of elements in a bin can be retrieved with
49 * gst_bin_iterate_elements(). Various other iterators exist to retrieve the
52 * gst_object_unref() is used to drop your reference to the bin.
54 * The #GstBin::element-added signal is fired whenever a new element is added to
55 * the bin. Likewise the #GstBin::element-removed signal is fired whenever an
56 * element is removed from the bin.
58 * <refsect2><title>Notes</title>
60 * A #GstBin internally intercepts every #GstMessage posted by its children and
61 * implements the following default behaviour for each of them:
64 * <term>GST_MESSAGE_EOS</term>
65 * <listitem><para>This message is only posted by sinks in the PLAYING
66 * state. If all sinks posted the EOS message, this bin will post and EOS
67 * message upwards.</para></listitem>
70 * <term>GST_MESSAGE_SEGMENT_START</term>
71 * <listitem><para>just collected and never forwarded upwards.
72 * The messages are used to decide when all elements have completed playback
73 * of their segment.</para></listitem>
76 * <term>GST_MESSAGE_SEGMENT_DONE</term>
77 * <listitem><para> Is posted by #GstBin when all elements that posted
78 * a SEGMENT_START have posted a SEGMENT_DONE.</para></listitem>
81 * <term>GST_MESSAGE_DURATION</term>
82 * <listitem><para> Is posted by an element that detected a change
83 * in the stream duration. The default bin behaviour is to clear any
84 * cached duration values so that the next duration query will perform
85 * a full duration recalculation. The duration change is posted to the
86 * application so that it can refetch the new duration with a duration
87 * query. Note that these messages can be posted before the bin is
88 * prerolled, in which case the duration query might fail.
92 * <term>GST_MESSAGE_CLOCK_LOST</term>
93 * <listitem><para> This message is posted by an element when it
94 * can no longer provide a clock. The default bin behaviour is to
95 * check if the lost clock was the one provided by the bin. If so and
96 * the bin is currently in the PLAYING state, the message is forwarded to
98 * This message is also generated when a clock provider is removed from
99 * the bin. If this message is received by the application, it should
100 * PAUSE the pipeline and set it back to PLAYING to force a new clock
105 * <term>GST_MESSAGE_CLOCK_PROVIDE</term>
106 * <listitem><para> This message is generated when an element
107 * can provide a clock. This mostly happens when a new clock
108 * provider is added to the bin. The default behaviour of the bin is to
109 * mark the currently selected clock as dirty, which will perform a clock
110 * recalculation the next time the bin is asked to provide a clock.
111 * This message is never sent tot the application but is forwarded to
112 * the parent of the bin.
116 * <term>OTHERS</term>
117 * <listitem><para> posted upwards.</para></listitem>
122 * A #GstBin implements the following default behaviour for answering to a
126 * <term>GST_QUERY_DURATION</term>
127 * <listitem><para>If the query has been asked before with the same format
128 * and the bin is a toplevel bin (ie. has no parent),
129 * use the cached previous value. If no previous value was cached, the
130 * query is sent to all sink elements in the bin and the MAXIMUM of all
131 * values is returned. If the bin is a toplevel bin the value is cached.
132 * If no sinks are available in the bin, the query fails.
136 * <term>GST_QUERY_POSITION</term>
137 * <listitem><para>The query is sent to all sink elements in the bin and the
138 * MAXIMUM of all values is returned. If no sinks are available in the bin,
143 * <term>OTHERS</term>
144 * <listitem><para>the query is forwarded to all sink elements, the result
145 * of the first sink that answers the query successfully is returned. If no
146 * sink is in the bin, the query fails.</para></listitem>
150 * A #GstBin will by default forward any event sent to it to all sink elements.
151 * If all the sinks return TRUE, the bin will also return TRUE, else FALSE is
152 * returned. If no sinks are in the bin, the event handler will return TRUE.
157 * Last reviewed on 2006-04-28 (0.10.6)
160 #include "gst_private.h"
162 #include "gstevent.h"
164 #include "gstmarshal.h"
166 #include "gsterror.h"
168 #include "gstindex.h"
169 #include "gstindexfactory.h"
170 #include "gstutils.h"
171 #include "gstchildproxy.h"
173 /* latency is by default enabled now.
174 * live-preroll and no-live-preroll in the environment var GST_COMPAT
175 * to enables or disable it respectively.
177 static gboolean enable_latency = TRUE;
179 GST_DEBUG_CATEGORY_STATIC (bin_debug);
180 #define GST_CAT_DEFAULT bin_debug
182 /* a bin is toplevel if it has no parent or when it is configured to behave like
184 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
186 #define GST_BIN_GET_PRIVATE(obj) \
187 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
189 struct _GstBinPrivate
191 gboolean asynchandling;
192 /* if we get an ASYNC_DONE message from ourselves, this means that the
193 * subclass will simulate ASYNC behaviour without having ASYNC children. When
194 * such an ASYNC_DONE message is posted while we are doing a state change, we
195 * have to process the message after finishing the state change even when no
196 * child returned GST_STATE_CHANGE_ASYNC. */
197 gboolean pending_async_done;
199 guint32 structure_cookie;
203 /* forward messages from our children */
204 gboolean message_forward;
216 static void gst_bin_dispose (GObject * object);
218 static void gst_bin_set_property (GObject * object, guint prop_id,
219 const GValue * value, GParamSpec * pspec);
220 static void gst_bin_get_property (GObject * object, guint prop_id,
221 GValue * value, GParamSpec * pspec);
223 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
224 GstStateChange transition);
225 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
226 GstState newstate, GstState pending);
227 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
228 GstState * state, GstState * pending, GstClockTime timeout);
229 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
230 gboolean flag_pending, gboolean reset_time);
231 static void bin_handle_async_start (GstBin * bin);
232 static void bin_push_state_continue (BinContinueData * data);
233 static void bin_do_eos (GstBin * bin);
235 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
236 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
238 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
239 static GstIndex *gst_bin_get_index_func (GstElement * element);
241 static GstClock *gst_bin_provide_clock_func (GstElement * element);
242 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
244 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
245 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
246 static GstBusSyncReply bin_bus_handler (GstBus * bus,
247 GstMessage * message, GstBin * bin);
248 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
250 static gboolean gst_bin_do_latency_func (GstBin * bin);
252 static void bin_remove_messages (GstBin * bin, GstObject * src,
253 GstMessageType types);
254 static void gst_bin_continue_func (BinContinueData * data);
255 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
256 static gint bin_element_is_src (GstElement * child, GstBin * bin);
258 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
260 /* Bin signals and properties */
269 #define DEFAULT_ASYNC_HANDLING FALSE
270 #define DEFAULT_MESSAGE_FORWARD FALSE
276 PROP_MESSAGE_FORWARD,
280 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
282 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
286 const gchar *compat; \
287 static const GInterfaceInfo iface_info = { \
288 gst_bin_child_proxy_init, \
292 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
294 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
295 "debugging info for the 'bin' container element"); \
297 /* compatibility stuff */ \
298 compat = g_getenv ("GST_COMPAT"); \
299 if (compat != NULL) { \
300 if (strstr (compat, "no-live-preroll")) \
301 enable_latency = FALSE; \
302 else if (strstr (compat, "live-preroll")) \
303 enable_latency = TRUE; \
307 #define gst_bin_parent_class parent_class
308 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
311 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
317 bin = GST_BIN_CAST (child_proxy);
319 GST_OBJECT_LOCK (bin);
320 if ((res = g_list_nth_data (bin->children, index)))
321 gst_object_ref (res);
322 GST_OBJECT_UNLOCK (bin);
328 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
333 bin = GST_BIN_CAST (child_proxy);
335 GST_OBJECT_LOCK (bin);
336 num = bin->numchildren;
337 GST_OBJECT_UNLOCK (bin);
343 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
345 GstChildProxyInterface *iface = g_iface;
347 iface->get_children_count = gst_bin_child_proxy_get_children_count;
348 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
352 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
353 GValue * return_accu, const GValue * handler_return, gpointer dummy)
357 myboolean = g_value_get_boolean (handler_return);
358 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
359 g_value_set_boolean (return_accu, myboolean);
361 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
368 gst_bin_class_init (GstBinClass * klass)
370 GObjectClass *gobject_class;
371 GstElementClass *gstelement_class;
374 gobject_class = (GObjectClass *) klass;
375 gstelement_class = (GstElementClass *) klass;
377 g_type_class_add_private (klass, sizeof (GstBinPrivate));
379 gobject_class->set_property = gst_bin_set_property;
380 gobject_class->get_property = gst_bin_get_property;
383 * GstBin:async-handling
385 * If set to #TRUE, the bin will handle asynchronous state changes.
386 * This should be used only if the bin subclass is modifying the state
387 * of its children on its own.
391 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
392 g_param_spec_boolean ("async-handling", "Async Handling",
393 "The bin will handle Asynchronous state changes",
394 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
397 * GstBin::element-added:
399 * @element: the #GstElement that was added to the bin
401 * Will be emitted after the element was added to the bin.
403 gst_bin_signals[ELEMENT_ADDED] =
404 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
405 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
406 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
408 * GstBin::element-removed:
410 * @element: the #GstElement that was removed from the bin
412 * Will be emitted after the element was removed from the bin.
414 gst_bin_signals[ELEMENT_REMOVED] =
415 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
416 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
417 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
419 * GstBin::do-latency:
422 * Will be emitted when the bin needs to perform latency calculations. This
423 * signal is only emited for toplevel bins or when async-handling is
426 * Only one signal handler is invoked. If no signals are connected, the
427 * default handler is invoked, which will query and distribute the lowest
428 * possible latency to all sinks.
430 * Connect to this signal if the default latency calculations are not
431 * sufficient, like when you need different latencies for different sinks in
436 gst_bin_signals[DO_LATENCY] =
437 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
438 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
439 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
440 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
443 * GstBin:message-forward
445 * Forward all children messages, even those that would normally be filtered by
446 * the bin. This can be interesting when one wants to be notified of the EOS
447 * state of individual elements, for example.
449 * The messages are converted to an ELEMENT message with the bin as the
450 * source. The structure of the message is named 'GstBinForwarded' and contains
451 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
456 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
457 g_param_spec_boolean ("message-forward", "Message Forward",
458 "Forwards all children messages",
459 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
461 gobject_class->dispose = gst_bin_dispose;
463 gst_element_class_set_metadata (gstelement_class, "Generic bin",
465 "Simple container object",
466 "Erik Walthinsen <omega@cse.ogi.edu>,"
467 "Wim Taymans <wim.taymans@gmail.com>");
469 gstelement_class->change_state =
470 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
471 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
472 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
473 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
474 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
475 gstelement_class->provide_clock =
476 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
477 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
479 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
480 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
482 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
483 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
484 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
486 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
488 GST_DEBUG ("creating bin thread pool");
491 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
493 g_critical ("could alloc threadpool %s", err->message);
498 gst_bin_init (GstBin * bin)
502 bin->numchildren = 0;
503 bin->children = NULL;
504 bin->children_cookie = 0;
505 bin->messages = NULL;
506 bin->provided_clock = NULL;
507 bin->clock_dirty = FALSE;
509 /* Set up a bus for listening to child elements */
510 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
511 bin->child_bus = bus;
512 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
514 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
516 bin->priv = GST_BIN_GET_PRIVATE (bin);
517 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
518 bin->priv->structure_cookie = 0;
519 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
523 gst_bin_dispose (GObject * object)
525 GstBin *bin = GST_BIN_CAST (object);
526 GstBus **child_bus_p = &bin->child_bus;
527 GstClock **provided_clock_p = &bin->provided_clock;
528 GstElement **clock_provider_p = &bin->clock_provider;
529 GstIndex **index_p = &bin->priv->index;
531 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
533 GST_OBJECT_LOCK (object);
534 gst_object_replace ((GstObject **) child_bus_p, NULL);
535 gst_object_replace ((GstObject **) provided_clock_p, NULL);
536 gst_object_replace ((GstObject **) clock_provider_p, NULL);
537 gst_object_replace ((GstObject **) index_p, NULL);
538 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
539 GST_OBJECT_UNLOCK (object);
541 while (bin->children) {
542 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
544 if (G_UNLIKELY (bin->children != NULL)) {
545 g_critical ("could not remove elements from bin '%s'",
546 GST_STR_NULL (GST_OBJECT_NAME (object)));
549 G_OBJECT_CLASS (parent_class)->dispose (object);
554 * @name: the name of the new bin
556 * Creates a new bin with the given name.
558 * Returns: (transfer full): a new #GstBin
561 gst_bin_new (const gchar * name)
563 return gst_element_factory_make ("bin", name);
567 gst_bin_set_property (GObject * object, guint prop_id,
568 const GValue * value, GParamSpec * pspec)
572 gstbin = GST_BIN_CAST (object);
575 case PROP_ASYNC_HANDLING:
576 GST_OBJECT_LOCK (gstbin);
577 gstbin->priv->asynchandling = g_value_get_boolean (value);
578 GST_OBJECT_UNLOCK (gstbin);
580 case PROP_MESSAGE_FORWARD:
581 GST_OBJECT_LOCK (gstbin);
582 gstbin->priv->message_forward = g_value_get_boolean (value);
583 GST_OBJECT_UNLOCK (gstbin);
586 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
592 gst_bin_get_property (GObject * object, guint prop_id,
593 GValue * value, GParamSpec * pspec)
597 gstbin = GST_BIN_CAST (object);
600 case PROP_ASYNC_HANDLING:
601 GST_OBJECT_LOCK (gstbin);
602 g_value_set_boolean (value, gstbin->priv->asynchandling);
603 GST_OBJECT_UNLOCK (gstbin);
605 case PROP_MESSAGE_FORWARD:
606 GST_OBJECT_LOCK (gstbin);
607 g_value_set_boolean (value, gstbin->priv->message_forward);
608 GST_OBJECT_UNLOCK (gstbin);
611 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
616 /* return the cached index */
618 gst_bin_get_index_func (GstElement * element)
623 bin = GST_BIN_CAST (element);
625 GST_OBJECT_LOCK (bin);
626 if ((result = bin->priv->index))
627 gst_object_ref (result);
628 GST_OBJECT_UNLOCK (bin);
633 /* set the index on all elements in this bin
638 gst_bin_set_index_func (GstElement * element, GstIndex * index)
644 GValue data = { 0, };
646 bin = GST_BIN_CAST (element);
648 GST_OBJECT_LOCK (bin);
649 old = bin->priv->index;
650 if (G_UNLIKELY (old == index))
653 gst_object_ref (index);
654 bin->priv->index = index;
655 GST_OBJECT_UNLOCK (bin);
658 gst_object_unref (old);
660 it = gst_bin_iterate_elements (bin);
662 /* set the index on all elements in the bin */
665 switch (gst_iterator_next (it, &data)) {
666 case GST_ITERATOR_OK:
668 GstElement *child = g_value_get_object (&data);
670 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
671 GST_ELEMENT_NAME (child));
672 gst_element_set_index (child, index);
674 g_value_reset (&data);
677 case GST_ITERATOR_RESYNC:
678 GST_DEBUG_OBJECT (bin, "iterator doing resync");
679 gst_iterator_resync (it);
682 case GST_ITERATOR_DONE:
683 GST_DEBUG_OBJECT (bin, "iterator done");
688 g_value_unset (&data);
689 gst_iterator_free (it);
694 GST_DEBUG_OBJECT (bin, "index was already set");
695 GST_OBJECT_UNLOCK (bin);
700 /* set the clock on all elements in this bin
705 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
711 GValue data = { 0, };
713 bin = GST_BIN_CAST (element);
715 it = gst_bin_iterate_elements (bin);
719 switch (gst_iterator_next (it, &data)) {
720 case GST_ITERATOR_OK:
722 GstElement *child = g_value_get_object (&data);
724 res &= gst_element_set_clock (child, clock);
726 g_value_reset (&data);
729 case GST_ITERATOR_RESYNC:
730 GST_DEBUG_OBJECT (bin, "iterator doing resync");
731 gst_iterator_resync (it);
735 case GST_ITERATOR_DONE:
736 GST_DEBUG_OBJECT (bin, "iterator done");
741 g_value_unset (&data);
742 gst_iterator_free (it);
745 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
750 /* get the clock for this bin by asking all of the children in this bin
752 * The ref of the returned clock in increased so unref after usage.
754 * We loop the elements in state order and pick the last clock we can
755 * get. This makes sure we get a clock from the source.
760 gst_bin_provide_clock_func (GstElement * element)
762 GstClock *result = NULL;
763 GstElement *provider = NULL;
768 GstClock **provided_clock_p;
769 GstElement **clock_provider_p;
771 bin = GST_BIN_CAST (element);
773 GST_OBJECT_LOCK (bin);
774 if (!bin->clock_dirty)
777 GST_DEBUG_OBJECT (bin, "finding new clock");
779 it = gst_bin_sort_iterator_new (bin);
780 GST_OBJECT_UNLOCK (bin);
784 switch (gst_iterator_next (it, &val)) {
785 case GST_ITERATOR_OK:
787 GstElement *child = g_value_get_object (&val);
790 clock = gst_element_provide_clock (child);
792 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
793 clock, GST_ELEMENT_NAME (child));
795 gst_object_unref (result);
796 gst_object_unref (provider);
799 provider = gst_object_ref (child);
802 g_value_reset (&val);
805 case GST_ITERATOR_RESYNC:
806 gst_iterator_resync (it);
809 case GST_ITERATOR_DONE:
814 g_value_unset (&val);
815 gst_iterator_free (it);
817 GST_OBJECT_LOCK (bin);
818 if (!bin->clock_dirty) {
820 gst_object_unref (provider);
822 gst_object_unref (result);
828 provided_clock_p = &bin->provided_clock;
829 clock_provider_p = &bin->clock_provider;
830 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
831 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
832 bin->clock_dirty = FALSE;
833 GST_DEBUG_OBJECT (bin,
834 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
836 /* Provider is not being returned to caller, just the result */
838 gst_object_unref (provider);
839 GST_OBJECT_UNLOCK (bin);
845 if ((result = bin->provided_clock))
846 gst_object_ref (result);
847 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
848 GST_OBJECT_UNLOCK (bin);
855 * functions for manipulating cached messages
860 GstMessageType types;
863 /* check if a message is of given src and type */
865 message_check (GstMessage * message, MessageFind * target)
870 eq &= GST_MESSAGE_SRC (message) == target->src;
872 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
873 GST_LOG ("looking at message %p: %d", message, eq);
879 find_message (GstBin * bin, GstObject * src, GstMessageType types)
887 result = g_list_find_custom (bin->messages, &find,
888 (GCompareFunc) message_check);
891 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
892 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
895 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
896 #ifndef GST_DISABLE_GST_DEBUG
900 for (i = 0; i < 32; i++)
901 if (types & (1 << i))
902 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
910 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
913 * A message that is cached and has the same SRC and type is replaced
914 * by the given message.
917 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
923 if ((src = GST_MESSAGE_SRC (message))) {
924 /* first find the previous message posted by this element */
925 if ((previous = find_message (bin, src, types))) {
926 GstMessage *previous_msg;
928 /* if we found a previous message, replace it */
929 previous_msg = previous->data;
930 previous->data = message;
932 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
933 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
934 GST_MESSAGE_TYPE_NAME (message));
936 gst_message_unref (previous_msg);
938 /* keep new message */
939 bin->messages = g_list_prepend (bin->messages, message);
941 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
942 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
945 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
946 GST_MESSAGE_TYPE_NAME (message));
948 gst_message_unref (message);
953 /* with LOCK. Remove all messages of given types */
955 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
963 for (walk = bin->messages; walk; walk = next) {
964 GstMessage *message = (GstMessage *) walk->data;
966 next = g_list_next (walk);
968 if (message_check (message, &find) == 0) {
969 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
970 "deleting message %p of types 0x%08x", message, types);
971 bin->messages = g_list_delete_link (bin->messages, walk);
972 gst_message_unref (message);
974 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
975 "not deleting message %p of type 0x%08x", message,
976 GST_MESSAGE_TYPE (message));
982 /* Check if the bin is EOS. We do this by scanning all sinks and
983 * checking if they posted an EOS message.
985 * call with bin LOCK */
987 is_eos (GstBin * bin, guint32 * seqnum)
994 for (walk = bin->children; walk; walk = g_list_next (walk)) {
997 element = GST_ELEMENT_CAST (walk->data);
998 if (bin_element_is_sink (element, bin) == 0) {
999 /* check if element posted EOS */
1001 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
1002 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1003 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1006 GST_DEBUG ("sink '%s' did not post EOS yet",
1007 GST_ELEMENT_NAME (element));
1013 /* FIXME: Some tests (e.g. elements/capsfilter) use
1014 * pipelines with a dangling sinkpad but no sink element.
1015 * These tests assume that no EOS message is ever
1016 * posted on the bus so let's keep that behaviour.
1017 * In valid pipelines this doesn't make a difference.
1019 return result && n_eos > 0;
1023 unlink_pads (const GValue * item, gpointer user_data)
1028 pad = g_value_get_object (item);
1030 if ((peer = gst_pad_get_peer (pad))) {
1031 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1032 gst_pad_unlink (pad, peer);
1034 gst_pad_unlink (peer, pad);
1035 gst_object_unref (peer);
1039 /* vmethod that adds an element to a bin
1044 gst_bin_add_func (GstBin * bin, GstElement * element)
1048 gboolean is_sink, is_source;
1049 GstMessage *clock_message = NULL, *async_message = NULL;
1050 GstStateChangeReturn ret;
1052 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1054 /* we obviously can't add ourself to ourself */
1055 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1058 /* get the element name to make sure it is unique in this bin. */
1059 GST_OBJECT_LOCK (element);
1060 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1061 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1062 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1063 GST_OBJECT_UNLOCK (element);
1065 GST_OBJECT_LOCK (bin);
1067 /* then check to see if the element's name is already taken in the bin,
1068 * we can safely take the lock here. This check is probably bogus because
1069 * you can safely change the element name after this check and before setting
1070 * the object parent. The window is very small though... */
1071 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1072 goto duplicate_name;
1074 /* set the element's parent and add the element to the bin's list of children */
1075 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1076 GST_OBJECT_CAST (bin))))
1079 /* if we add a sink we become a sink */
1081 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1083 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1086 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1088 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1090 if (gst_element_provides_clock (element)) {
1091 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1093 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1096 bin->children = g_list_prepend (bin->children, element);
1098 bin->children_cookie++;
1099 bin->priv->structure_cookie++;
1101 /* distribute the bus */
1102 gst_element_set_bus (element, bin->child_bus);
1104 /* propagate the current base_time, start_time and clock */
1105 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1106 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1107 /* it's possible that the element did not accept the clock but
1108 * that is not important right now. When the pipeline goes to PLAYING,
1109 * a new clock will be selected */
1110 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1111 /* set the cached index on the children */
1112 if (bin->priv->index)
1113 gst_element_set_index (element, bin->priv->index);
1115 ret = GST_STATE_RETURN (bin);
1116 /* no need to update the state if we are in error */
1117 if (ret == GST_STATE_CHANGE_FAILURE)
1118 goto no_state_recalc;
1120 /* update the bin state, the new element could have been an ASYNC or
1121 * NO_PREROLL element */
1122 ret = GST_STATE_RETURN (element);
1123 GST_DEBUG_OBJECT (bin, "added %s element",
1124 gst_element_state_change_return_get_name (ret));
1127 case GST_STATE_CHANGE_ASYNC:
1129 /* create message to track this aync element when it posts an async-done
1131 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1134 case GST_STATE_CHANGE_NO_PREROLL:
1135 /* ignore all async elements we might have and commit our state */
1136 bin_handle_async_done (bin, ret, FALSE, FALSE);
1138 case GST_STATE_CHANGE_FAILURE:
1145 GST_OBJECT_UNLOCK (bin);
1147 /* post the messages on the bus of the element so that the bin can handle
1150 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1153 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1155 /* unlink all linked pads */
1156 it = gst_element_iterate_pads (element);
1157 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1158 gst_iterator_free (it);
1160 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1164 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1165 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1169 /* ERROR handling here */
1172 GST_OBJECT_LOCK (bin);
1173 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1174 GST_OBJECT_UNLOCK (bin);
1179 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1180 elem_name, GST_ELEMENT_NAME (bin));
1181 GST_OBJECT_UNLOCK (bin);
1187 g_warning ("Element '%s' already has parent", elem_name);
1188 GST_OBJECT_UNLOCK (bin);
1197 * @element: (transfer full): the #GstElement to add
1199 * Adds the given element to the bin. Sets the element's parent, and thus
1200 * takes ownership of the element. An element can only be added to one bin.
1202 * If the element's pads are linked to other pads, the pads will be unlinked
1203 * before the element is added to the bin.
1206 * When you add an element to an already-running pipeline, you will have to
1207 * take care to set the state of the newly-added element to the desired
1208 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1209 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1210 * The bin or pipeline will not take care of this for you.
1215 * Returns: TRUE if the element could be added, FALSE if
1216 * the bin does not want to accept the element.
1219 gst_bin_add (GstBin * bin, GstElement * element)
1221 GstBinClass *bclass;
1224 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1225 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1227 bclass = GST_BIN_GET_CLASS (bin);
1229 if (G_UNLIKELY (bclass->add_element == NULL))
1232 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1233 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1234 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1236 result = bclass->add_element (bin, element);
1240 /* ERROR handling */
1243 g_warning ("adding elements to bin '%s' is not supported",
1244 GST_ELEMENT_NAME (bin));
1249 /* remove an element from the bin
1254 gst_bin_remove_func (GstBin * bin, GstElement * element)
1258 gboolean is_sink, is_source, othersink, othersource, found;
1259 GstMessage *clock_message = NULL;
1260 GstClock **provided_clock_p;
1261 GstElement **clock_provider_p;
1263 gboolean other_async, this_async, have_no_preroll;
1264 GstStateChangeReturn ret;
1266 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1268 GST_OBJECT_LOCK (element);
1269 /* Check if the element is already being removed and immediately
1271 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element,
1272 GST_ELEMENT_FLAG_UNPARENTING)))
1273 goto already_removing;
1275 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_FLAG_UNPARENTING);
1276 /* grab element name so we can print it */
1277 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1278 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1279 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1280 GST_OBJECT_UNLOCK (element);
1282 /* unlink all linked pads */
1283 it = gst_element_iterate_pads (element);
1284 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1285 gst_iterator_free (it);
1287 GST_OBJECT_LOCK (bin);
1290 othersource = FALSE;
1291 have_no_preroll = FALSE;
1292 /* iterate the elements, we collect which ones are async and no_preroll. We
1293 * also remove the element when we find it. */
1294 for (walk = bin->children; walk; walk = next) {
1295 GstElement *child = GST_ELEMENT_CAST (walk->data);
1297 next = g_list_next (walk);
1299 if (child == element) {
1301 /* remove the element */
1302 bin->children = g_list_delete_link (bin->children, walk);
1304 gboolean child_sink, child_source;
1306 GST_OBJECT_LOCK (child);
1307 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1308 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1309 /* when we remove a sink, check if there are other sinks. */
1310 if (is_sink && !othersink && child_sink)
1312 if (is_source && !othersource && child_source)
1314 /* check if we have NO_PREROLL children */
1315 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1316 have_no_preroll = TRUE;
1317 GST_OBJECT_UNLOCK (child);
1321 /* the element must have been in the bin's list of children */
1322 if (G_UNLIKELY (!found))
1325 /* we now removed the element from the list of elements, increment the cookie
1326 * so that others can detect a change in the children list. */
1328 bin->children_cookie++;
1329 bin->priv->structure_cookie++;
1331 if (is_sink && !othersink) {
1332 /* we're not a sink anymore */
1333 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1334 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1336 if (is_source && !othersource) {
1337 /* we're not a source anymore */
1338 GST_DEBUG_OBJECT (bin, "we removed the last source");
1339 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1343 /* if the clock provider for this element is removed, we lost
1344 * the clock as well, we need to inform the parent of this
1345 * so that it can select a new clock */
1346 if (bin->clock_provider == element) {
1347 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1348 bin->clock_dirty = TRUE;
1350 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1351 provided_clock_p = &bin->provided_clock;
1352 clock_provider_p = &bin->clock_provider;
1353 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1354 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1357 /* remove messages for the element, if there was a pending ASYNC_START
1358 * message we must see if removing the element caused the bin to lose its
1361 other_async = FALSE;
1362 for (walk = bin->messages; walk; walk = next) {
1363 GstMessage *message = (GstMessage *) walk->data;
1364 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1367 next = g_list_next (walk);
1370 switch (GST_MESSAGE_TYPE (message)) {
1371 case GST_MESSAGE_ASYNC_START:
1377 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1379 case GST_MESSAGE_STRUCTURE_CHANGE:
1383 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1385 /* it's unlikely that this message is still in the list of messages
1386 * because this would mean that a link/unlink is busy in another thread
1387 * while we remove the element. We still have to remove the message
1388 * because we might not receive the done message anymore when the element
1389 * is removed from the bin. */
1390 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1391 if (owner == element)
1402 /* delete all message types */
1403 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1404 message, elem_name);
1405 bin->messages = g_list_delete_link (bin->messages, walk);
1406 gst_message_unref (message);
1410 /* get last return */
1411 ret = GST_STATE_RETURN (bin);
1413 /* no need to update the state if we are in error */
1414 if (ret == GST_STATE_CHANGE_FAILURE)
1415 goto no_state_recalc;
1417 if (!other_async && this_async) {
1418 /* all other elements were not async and we removed the async one,
1419 * handle the async-done case because we are not async anymore now. */
1420 GST_DEBUG_OBJECT (bin,
1421 "we removed the last async element, have no_preroll %d",
1424 /* the current state return of the bin depends on if there are no_preroll
1425 * elements in the pipeline or not */
1426 if (have_no_preroll)
1427 ret = GST_STATE_CHANGE_NO_PREROLL;
1429 ret = GST_STATE_CHANGE_SUCCESS;
1431 bin_handle_async_done (bin, ret, FALSE, FALSE);
1433 GST_DEBUG_OBJECT (bin,
1434 "recalc state preroll: %d, other async: %d, this async %d",
1435 have_no_preroll, other_async, this_async);
1437 if (have_no_preroll) {
1438 ret = GST_STATE_CHANGE_NO_PREROLL;
1439 } else if (other_async) {
1440 /* there are other async elements and we were not doing an async state
1441 * change, change our pending state and go async */
1442 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1443 GST_STATE_NEXT (bin) = GST_STATE (bin);
1444 GST_STATE_PENDING (bin) = GST_STATE (bin);
1446 ret = GST_STATE_CHANGE_ASYNC;
1448 GST_STATE_RETURN (bin) = ret;
1451 GST_OBJECT_UNLOCK (bin);
1454 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1456 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1460 gst_element_set_bus (element, NULL);
1462 /* Clear the clock we provided to the element */
1463 gst_element_set_clock (element, NULL);
1465 /* we ref here because after the _unparent() the element can be disposed
1466 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1467 gst_object_ref (element);
1468 gst_object_unparent (GST_OBJECT_CAST (element));
1470 GST_OBJECT_LOCK (element);
1471 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_FLAG_UNPARENTING);
1472 GST_OBJECT_UNLOCK (element);
1474 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1475 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1477 /* element is really out of our control now */
1478 gst_object_unref (element);
1482 /* ERROR handling */
1485 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1486 GST_ELEMENT_NAME (bin));
1487 GST_OBJECT_UNLOCK (bin);
1493 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1494 GST_OBJECT_UNLOCK (element);
1502 * @element: (transfer none): the #GstElement to remove
1504 * Removes the element from the bin, unparenting it as well.
1505 * Unparenting the element means that the element will be dereferenced,
1506 * so if the bin holds the only reference to the element, the element
1507 * will be freed in the process of removing it from the bin. If you
1508 * want the element to still exist after removing, you need to call
1509 * gst_object_ref() before removing it from the bin.
1511 * If the element's pads are linked to other pads, the pads will be unlinked
1512 * before the element is removed from the bin.
1516 * Returns: TRUE if the element could be removed, FALSE if
1517 * the bin does not want to remove the element.
1520 gst_bin_remove (GstBin * bin, GstElement * element)
1522 GstBinClass *bclass;
1525 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1526 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1528 bclass = GST_BIN_GET_CLASS (bin);
1530 if (G_UNLIKELY (bclass->remove_element == NULL))
1533 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1534 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1536 result = bclass->remove_element (bin, element);
1540 /* ERROR handling */
1543 g_warning ("removing elements from bin '%s' is not supported",
1544 GST_ELEMENT_NAME (bin));
1550 * gst_bin_iterate_elements:
1553 * Gets an iterator for the elements in this bin.
1555 * Each element yielded by the iterator will have its refcount increased, so
1558 * MT safe. Caller owns returned value.
1560 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1563 gst_bin_iterate_elements (GstBin * bin)
1565 GstIterator *result;
1567 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1569 GST_OBJECT_LOCK (bin);
1570 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1571 GST_OBJECT_GET_LOCK (bin),
1572 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1573 GST_OBJECT_UNLOCK (bin);
1578 static GstIteratorItem
1579 iterate_child_recurse (GstIterator * it, const GValue * item)
1581 GstElement *child = g_value_get_object (item);
1583 if (GST_IS_BIN (child)) {
1584 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1586 gst_iterator_push (it, other);
1588 return GST_ITERATOR_ITEM_PASS;
1592 * gst_bin_iterate_recurse:
1595 * Gets an iterator for the elements in this bin.
1596 * This iterator recurses into GstBin children.
1598 * Each element yielded by the iterator will have its refcount increased, so
1601 * MT safe. Caller owns returned value.
1603 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1606 gst_bin_iterate_recurse (GstBin * bin)
1608 GstIterator *result;
1610 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1612 GST_OBJECT_LOCK (bin);
1613 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1614 GST_OBJECT_GET_LOCK (bin),
1615 &bin->children_cookie,
1617 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1618 GST_OBJECT_UNLOCK (bin);
1623 /* returns 0 when TRUE because this is a GCompareFunc */
1626 bin_element_is_sink (GstElement * child, GstBin * bin)
1630 /* we lock the child here for the remainder of the function to
1631 * get its name and flag safely. */
1632 GST_OBJECT_LOCK (child);
1633 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1635 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1636 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1638 GST_OBJECT_UNLOCK (child);
1639 return is_sink ? 0 : 1;
1643 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1645 GstBin *bin = g_value_get_object (vbin);
1646 GstElement *child = g_value_get_object (vchild);
1648 return (bin_element_is_sink (child, bin));
1652 * gst_bin_iterate_sinks:
1655 * Gets an iterator for all elements in the bin that have the
1656 * #GST_ELEMENT_FLAG_SINK flag set.
1658 * Each element yielded by the iterator will have its refcount increased, so
1661 * MT safe. Caller owns returned value.
1663 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1666 gst_bin_iterate_sinks (GstBin * bin)
1668 GstIterator *children;
1669 GstIterator *result;
1670 GValue vbin = { 0, };
1672 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1674 g_value_init (&vbin, GST_TYPE_BIN);
1675 g_value_set_object (&vbin, bin);
1677 children = gst_bin_iterate_elements (bin);
1678 result = gst_iterator_filter (children,
1679 (GCompareFunc) sink_iterator_filter, &vbin);
1681 g_value_unset (&vbin);
1686 /* returns 0 when TRUE because this is a GCompareFunc */
1689 bin_element_is_src (GstElement * child, GstBin * bin)
1693 /* we lock the child here for the remainder of the function to
1694 * get its name and other info safely. */
1695 GST_OBJECT_LOCK (child);
1696 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1698 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1699 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1701 GST_OBJECT_UNLOCK (child);
1702 return is_src ? 0 : 1;
1706 src_iterator_filter (const GValue * vchild, GValue * vbin)
1708 GstBin *bin = g_value_get_object (vbin);
1709 GstElement *child = g_value_get_object (vchild);
1711 return (bin_element_is_src (child, bin));
1715 * gst_bin_iterate_sources:
1718 * Gets an iterator for all elements in the bin that have the
1719 * #GST_ELEMENT_FLAG_SOURCE flag set.
1721 * Each element yielded by the iterator will have its refcount increased, so
1724 * MT safe. Caller owns returned value.
1726 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1729 gst_bin_iterate_sources (GstBin * bin)
1731 GstIterator *children;
1732 GstIterator *result;
1733 GValue vbin = { 0, };
1735 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1737 g_value_init (&vbin, GST_TYPE_BIN);
1738 g_value_set_object (&vbin, bin);
1740 children = gst_bin_iterate_elements (bin);
1741 result = gst_iterator_filter (children,
1742 (GCompareFunc) src_iterator_filter, &vbin);
1744 g_value_unset (&vbin);
1752 static GstStateChangeReturn
1753 gst_bin_get_state_func (GstElement * element, GstState * state,
1754 GstState * pending, GstClockTime timeout)
1756 GstStateChangeReturn ret;
1758 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1761 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1767 /***********************************************
1768 * Topologically sorted iterator
1769 * see http://en.wikipedia.org/wiki/Topological_sorting
1771 * For each element in the graph, an entry is kept in a HashTable
1772 * with its number of srcpad connections (degree).
1773 * We then change state of all elements without dependencies
1774 * (degree 0) and decrement the degree of all elements connected
1775 * on the sinkpads. When an element reaches degree 0, its state is
1777 * When all elements are handled the algorithm stops.
1779 typedef struct _GstBinSortIterator
1782 GQueue queue; /* elements queued for state change */
1783 GstBin *bin; /* bin we iterate */
1784 gint mode; /* adding or removing dependency */
1785 GstElement *best; /* next element with least dependencies */
1786 gint best_deg; /* best degree */
1787 GHashTable *hash; /* hashtable with element dependencies */
1788 gboolean dirty; /* we detected structure change */
1789 } GstBinSortIterator;
1792 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1793 GstBinSortIterator * copy)
1795 GHashTableIter iter;
1796 gpointer key, value;
1798 copy->queue = it->queue;
1799 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1801 copy->bin = gst_object_ref (it->bin);
1803 copy->best = gst_object_ref (it->best);
1805 copy->hash = g_hash_table_new (NULL, NULL);
1806 g_hash_table_iter_init (&iter, it->hash);
1807 while (g_hash_table_iter_next (&iter, &key, &value))
1808 g_hash_table_insert (copy->hash, key, value);
1811 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1812 #define HASH_SET_DEGREE(bit, elem, deg) \
1813 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1814 #define HASH_GET_DEGREE(bit, elem) \
1815 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1817 /* add element to queue of next elements in the iterator.
1818 * We push at the tail to give higher priority elements a
1821 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1823 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1824 GST_ELEMENT_NAME (element));
1825 gst_object_ref (element);
1826 g_queue_push_tail (&bit->queue, element);
1827 HASH_SET_DEGREE (bit, element, -1);
1831 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1835 if ((find = g_queue_find (&bit->queue, element))) {
1836 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1837 GST_ELEMENT_NAME (element));
1839 g_queue_delete_link (&bit->queue, find);
1840 gst_object_unref (element);
1842 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1843 GST_ELEMENT_NAME (element));
1847 /* clear the queue, unref all objects as we took a ref when
1848 * we added them to the queue */
1850 clear_queue (GQueue * queue)
1854 while ((p = g_queue_pop_head (queue)))
1855 gst_object_unref (p);
1858 /* set all degrees to 0. Elements marked as a sink are
1859 * added to the queue immediately. Since we only look at the SINK flag of the
1860 * element, it is possible that we add non-sinks to the queue. These will be
1861 * removed from the queue again when we can prove that it provides data for some
1864 reset_degree (GstElement * element, GstBinSortIterator * bit)
1868 /* sinks are added right away */
1869 GST_OBJECT_LOCK (element);
1870 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1871 GST_OBJECT_UNLOCK (element);
1874 add_to_queue (bit, element);
1876 /* others are marked with 0 and handled when sinks are done */
1877 HASH_SET_DEGREE (bit, element, 0);
1881 /* adjust the degree of all elements connected to the given
1882 * element. If a degree of an element drops to 0, it is
1883 * added to the queue of elements to schedule next.
1885 * We have to make sure not to cross the bin boundary this element
1889 update_degree (GstElement * element, GstBinSortIterator * bit)
1891 gboolean linked = FALSE;
1893 GST_OBJECT_LOCK (element);
1894 /* don't touch degree if element has no sinkpads */
1895 if (element->numsinkpads != 0) {
1896 /* loop over all sinkpads, decrement degree for all connected
1897 * elements in this bin */
1900 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1903 pad = GST_PAD_CAST (pads->data);
1905 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1906 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1907 GST_MESSAGE_STRUCTURE_CHANGE))) {
1908 /* mark the iterator as dirty because we won't be updating the degree
1909 * of the peer parent now. This would result in the 'loop detected'
1910 * later on because the peer parent element could become the best next
1911 * element with a degree > 0. We will simply continue our state
1912 * changes and we'll eventually resync when the unlink completed and
1913 * the iterator cookie is updated. */
1918 if ((peer = gst_pad_get_peer (pad))) {
1919 GstElement *peer_element;
1921 if ((peer_element = gst_pad_get_parent_element (peer))) {
1922 GST_OBJECT_LOCK (peer_element);
1923 /* check that we don't go outside of this bin */
1924 if (GST_OBJECT_CAST (peer_element)->parent ==
1925 GST_OBJECT_CAST (bit->bin)) {
1926 gint old_deg, new_deg;
1928 old_deg = HASH_GET_DEGREE (bit, peer_element);
1930 /* check to see if we added an element as sink that was not really a
1931 * sink because it was connected to some other element. */
1932 if (old_deg == -1) {
1933 remove_from_queue (bit, peer_element);
1936 new_deg = old_deg + bit->mode;
1938 GST_DEBUG_OBJECT (bit->bin,
1939 "change element %s, degree %d->%d, linked to %s",
1940 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1941 GST_ELEMENT_NAME (element));
1943 /* update degree, it is possible that an element was in 0 and
1944 * reaches -1 here. This would mean that the element had no sinkpads
1945 * but became linked while the state change was happening. We will
1946 * resync on this with the structure change message. */
1948 /* degree hit 0, add to queue */
1949 add_to_queue (bit, peer_element);
1951 HASH_SET_DEGREE (bit, peer_element, new_deg);
1955 GST_OBJECT_UNLOCK (peer_element);
1956 gst_object_unref (peer_element);
1958 gst_object_unref (peer);
1963 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1964 GST_ELEMENT_NAME (element));
1966 GST_OBJECT_UNLOCK (element);
1969 /* find the next best element not handled yet. This is the one
1970 * with the lowest non-negative degree */
1972 find_element (GstElement * element, GstBinSortIterator * bit)
1976 /* element is already handled */
1977 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1980 /* first element or element with smaller degree */
1981 if (bit->best == NULL || bit->best_deg > degree) {
1982 bit->best = element;
1983 bit->best_deg = degree;
1987 /* get next element in iterator. the returned element has the
1988 * refcount increased */
1989 static GstIteratorResult
1990 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
1993 GstBin *bin = bit->bin;
1995 /* empty queue, we have to find a next best element */
1996 if (g_queue_is_empty (&bit->queue)) {
1998 bit->best_deg = G_MAXINT;
1999 g_list_foreach (bin->children, (GFunc) find_element, bit);
2000 if ((best = bit->best)) {
2001 /* when we detected an unlink, don't warn because our degrees might be
2002 * screwed up. We will resync later */
2003 if (bit->best_deg != 0 && !bit->dirty) {
2004 /* we don't fail on this one yet */
2005 GST_WARNING_OBJECT (bin, "loop dected in graph");
2006 g_warning ("loop detected in the graph of bin '%s'!!",
2007 GST_ELEMENT_NAME (bin));
2009 /* best unhandled element, schedule as next element */
2010 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2011 GST_ELEMENT_NAME (best));
2012 HASH_SET_DEGREE (bit, best, -1);
2013 g_value_set_object (result, best);
2015 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2016 /* no more unhandled elements, we are done */
2017 return GST_ITERATOR_DONE;
2020 /* everything added to the queue got reffed */
2021 best = g_queue_pop_head (&bit->queue);
2022 g_value_set_object (result, best);
2023 gst_object_unref (best);
2026 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2027 /* update degrees of linked elements */
2028 update_degree (best, bit);
2030 return GST_ITERATOR_OK;
2033 /* clear queues, recalculate the degrees and restart. */
2035 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2037 GstBin *bin = bit->bin;
2039 GST_DEBUG_OBJECT (bin, "resync");
2041 clear_queue (&bit->queue);
2043 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2044 /* calc degrees, incrementing */
2046 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2047 /* for the rest of the function we decrement the degrees */
2051 /* clear queues, unref bin and free iterator. */
2053 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2055 GstBin *bin = bit->bin;
2057 GST_DEBUG_OBJECT (bin, "free");
2058 clear_queue (&bit->queue);
2059 g_hash_table_destroy (bit->hash);
2060 gst_object_unref (bin);
2063 /* should be called with the bin LOCK held */
2064 static GstIterator *
2065 gst_bin_sort_iterator_new (GstBin * bin)
2067 GstBinSortIterator *result;
2069 /* we don't need an ItemFunction because we ref the items in the _next
2071 result = (GstBinSortIterator *)
2072 gst_iterator_new (sizeof (GstBinSortIterator),
2074 GST_OBJECT_GET_LOCK (bin),
2075 &bin->priv->structure_cookie,
2076 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2077 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2078 (GstIteratorItemFunction) NULL,
2079 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2080 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2081 g_queue_init (&result->queue);
2082 result->hash = g_hash_table_new (NULL, NULL);
2083 gst_object_ref (bin);
2085 gst_bin_sort_iterator_resync (result);
2087 return (GstIterator *) result;
2091 * gst_bin_iterate_sorted:
2094 * Gets an iterator for the elements in this bin in topologically
2095 * sorted order. This means that the elements are returned from
2096 * the most downstream elements (sinks) to the sources.
2098 * This function is used internally to perform the state changes
2099 * of the bin elements and for clock selection.
2101 * Each element yielded by the iterator will have its refcount increased, so
2104 * MT safe. Caller owns returned value.
2106 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2109 gst_bin_iterate_sorted (GstBin * bin)
2111 GstIterator *result;
2113 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2115 GST_OBJECT_LOCK (bin);
2116 result = gst_bin_sort_iterator_new (bin);
2117 GST_OBJECT_UNLOCK (bin);
2122 static GstStateChangeReturn
2123 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2124 GstClockTime base_time, GstClockTime start_time, GstState current,
2127 GstStateChangeReturn ret;
2128 GstState pending, child_current, child_pending;
2132 GST_STATE_LOCK (element);
2134 GST_OBJECT_LOCK (element);
2135 /* set base_time and start time on child */
2136 GST_ELEMENT_START_TIME (element) = start_time;
2137 element->base_time = base_time;
2138 /* peel off the locked flag */
2139 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2140 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2141 ret = GST_STATE_RETURN (element);
2142 child_current = GST_STATE (element);
2143 child_pending = GST_STATE_PENDING (element);
2144 GST_OBJECT_UNLOCK (element);
2146 /* skip locked elements */
2147 if (G_UNLIKELY (locked))
2150 /* if the element was no preroll, just start changing the state regardless
2151 * if it had async elements (in the case of a bin) because they won't preroll
2153 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2154 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2158 GST_OBJECT_LOCK (bin);
2159 pending = GST_STATE_PENDING (bin);
2161 /* Try not to change the state of elements that are already in the state we're
2163 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2164 (child_pending == GST_STATE_VOID_PENDING &&
2165 ((pending > child_current && next > child_current) ||
2166 (pending < child_current && next < child_current)))))
2169 /* the element was busy with an upwards async state change, we must wait for
2170 * an ASYNC_DONE message before we attemp to change the state. */
2172 find_message (bin, GST_OBJECT_CAST (element),
2173 GST_MESSAGE_ASYNC_START))) {
2174 #ifndef GST_DISABLE_GST_DEBUG
2175 GstMessage *message = GST_MESSAGE_CAST (found->data);
2177 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2178 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2180 /* only wait for upward state changes */
2181 if (next > current) {
2182 /* We found an async element check if we can force its state to change or
2183 * if we have to wait for it to preroll. */
2184 if (G_UNLIKELY (!enable_latency)) {
2185 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2186 "\tto preroll in order to perform correct latency calculations.\n"
2187 "\tPlease verify that the application continues to work correctly by\n"
2188 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2189 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2196 GST_OBJECT_UNLOCK (bin);
2199 GST_DEBUG_OBJECT (bin,
2200 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2201 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2202 GST_TIME_ARGS (base_time));
2205 ret = gst_element_set_state (element, next);
2207 GST_STATE_UNLOCK (element);
2213 GST_DEBUG_OBJECT (element,
2214 "element is locked, return previous return %s",
2215 gst_element_state_change_return_get_name (ret));
2216 GST_STATE_UNLOCK (element);
2221 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2222 GST_OBJECT_UNLOCK (bin);
2223 GST_STATE_UNLOCK (element);
2224 return GST_STATE_CHANGE_ASYNC;
2228 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2229 "skipping transition from %s to %s, since bin pending"
2230 " is %s : last change state return follows",
2231 gst_element_state_get_name (child_current),
2232 gst_element_state_get_name (next),
2233 gst_element_state_get_name (pending));
2234 GST_OBJECT_UNLOCK (bin);
2235 GST_STATE_UNLOCK (element);
2240 /* gst_iterator_fold functions for pads_activate
2241 * Stop the iterator if activating one pad failed. */
2243 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2245 GstPad *pad = g_value_get_object (vpad);
2246 gboolean cont = TRUE;
2248 if (!(cont = gst_pad_set_active (pad, *active)))
2249 g_value_set_boolean (ret, FALSE);
2254 /* returns false on error or early cutout of the fold, true if all
2255 * pads in @iter were (de)activated successfully. */
2257 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2259 GstIteratorResult ires;
2262 /* no need to unset this later, it's just a boolean */
2263 g_value_init (&ret, G_TYPE_BOOLEAN);
2264 g_value_set_boolean (&ret, TRUE);
2267 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2270 case GST_ITERATOR_RESYNC:
2271 /* need to reset the result again */
2272 g_value_set_boolean (&ret, TRUE);
2273 gst_iterator_resync (iter);
2275 case GST_ITERATOR_DONE:
2276 /* all pads iterated, return collected value */
2279 /* iterator returned _ERROR or premature end with _OK,
2280 * mark an error and exit */
2281 g_value_set_boolean (&ret, FALSE);
2286 /* return collected value */
2287 return g_value_get_boolean (&ret);
2290 /* is called with STATE_LOCK
2293 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2298 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2300 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2301 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2302 gst_iterator_free (iter);
2303 if (G_UNLIKELY (!fold_ok))
2306 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2313 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2319 * gst_bin_recalculate_latency:
2322 * Query @bin for the current latency using and reconfigures this latency to all the
2323 * elements with a LATENCY event.
2325 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2326 * is posted on the bus.
2328 * This function simply emits the 'do-latency' signal so any custom latency
2329 * calculations will be performed.
2331 * Returns: %TRUE if the latency could be queried and reconfigured.
2336 gst_bin_recalculate_latency (GstBin * bin)
2340 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2341 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2347 gst_bin_do_latency_func (GstBin * bin)
2350 GstElement *element;
2351 GstClockTime min_latency, max_latency;
2354 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2356 element = GST_ELEMENT_CAST (bin);
2358 GST_DEBUG_OBJECT (element, "querying latency");
2360 query = gst_query_new_latency ();
2361 if ((res = gst_element_query (element, query))) {
2364 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2366 GST_DEBUG_OBJECT (element,
2367 "got min latency %" GST_TIME_FORMAT ", max latency %"
2368 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2369 GST_TIME_ARGS (max_latency), live);
2371 if (max_latency < min_latency) {
2372 /* this is an impossible situation, some parts of the pipeline might not
2373 * work correctly. We post a warning for now. */
2374 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2375 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2376 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2377 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2380 /* configure latency on elements */
2381 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2383 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2384 GST_TIME_ARGS (min_latency));
2386 GST_WARNING_OBJECT (element,
2387 "did not really configure latency of %" GST_TIME_FORMAT,
2388 GST_TIME_ARGS (min_latency));
2391 /* this is not a real problem, we just don't configure any latency. */
2392 GST_WARNING_OBJECT (element, "failed to query latency");
2394 gst_query_unref (query);
2400 gst_bin_state_changed (GstElement * element, GstState oldstate,
2401 GstState newstate, GstState pending)
2403 GstElementClass *pklass = (GstElementClass *) parent_class;
2405 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2406 bin_do_eos (GST_BIN_CAST (element));
2408 if (pklass->state_changed)
2409 pklass->state_changed (element, oldstate, newstate, pending);
2412 static GstStateChangeReturn
2413 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2416 GstStateChangeReturn ret;
2417 GstState current, next;
2418 gboolean have_async;
2419 gboolean have_no_preroll;
2420 GstClockTime base_time, start_time;
2423 GValue data = { 0, };
2425 /* we don't need to take the STATE_LOCK, it is already taken */
2426 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2427 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2429 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2430 "changing state of children from %s to %s",
2431 gst_element_state_get_name (current), gst_element_state_get_name (next));
2433 bin = GST_BIN_CAST (element);
2436 case GST_STATE_PLAYING:
2440 GST_OBJECT_LOCK (bin);
2441 toplevel = BIN_IS_TOPLEVEL (bin);
2442 GST_OBJECT_UNLOCK (bin);
2445 gst_bin_recalculate_latency (bin);
2448 case GST_STATE_PAUSED:
2449 /* Clear EOS list on next PAUSED */
2450 GST_OBJECT_LOCK (bin);
2451 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2452 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2453 bin->priv->posted_eos = FALSE;
2454 GST_OBJECT_UNLOCK (bin);
2455 if (current == GST_STATE_READY)
2456 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2457 goto activate_failure;
2459 case GST_STATE_READY:
2460 /* Clear message list on next READY */
2461 GST_OBJECT_LOCK (bin);
2462 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2463 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2464 GST_OBJECT_UNLOCK (bin);
2465 if (current == GST_STATE_PAUSED)
2466 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2467 goto activate_failure;
2469 case GST_STATE_NULL:
2470 if (current == GST_STATE_READY)
2471 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2472 goto activate_failure;
2478 /* this flag is used to make the async state changes return immediately. We
2479 * don't want them to interfere with this state change */
2480 GST_OBJECT_LOCK (bin);
2481 bin->polling = TRUE;
2482 GST_OBJECT_UNLOCK (bin);
2484 /* iterate in state change order */
2485 it = gst_bin_iterate_sorted (bin);
2487 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2488 * Note how we don't reset this value when a resync happens, the reason being
2489 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2490 * even after a resync when the async element is gone */
2494 /* take base_time */
2495 base_time = gst_element_get_base_time (element);
2496 start_time = gst_element_get_start_time (element);
2498 have_no_preroll = FALSE;
2502 switch (gst_iterator_next (it, &data)) {
2503 case GST_ITERATOR_OK:
2507 child = g_value_get_object (&data);
2509 /* set state and base_time now */
2510 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2514 case GST_STATE_CHANGE_SUCCESS:
2515 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2516 "child '%s' changed state to %d(%s) successfully",
2517 GST_ELEMENT_NAME (child), next,
2518 gst_element_state_get_name (next));
2520 case GST_STATE_CHANGE_ASYNC:
2522 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2523 "child '%s' is changing state asynchronously to %s",
2524 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2528 case GST_STATE_CHANGE_FAILURE:{
2531 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2532 "child '%s' failed to go to state %d(%s)",
2533 GST_ELEMENT_NAME (child),
2534 next, gst_element_state_get_name (next));
2536 /* Only fail if the child is still inside
2537 * this bin. It might've been removed already
2538 * because of the error by the bin subclass
2539 * to ignore the error. */
2540 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2541 if (parent == GST_OBJECT_CAST (element)) {
2542 /* element is still in bin, really error now */
2543 gst_object_unref (parent);
2546 /* child removed from bin, let the resync code redo the state
2548 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2549 "child '%s' was removed from the bin",
2550 GST_ELEMENT_NAME (child));
2553 gst_object_unref (parent);
2557 case GST_STATE_CHANGE_NO_PREROLL:
2558 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2559 "child '%s' changed state to %d(%s) successfully without preroll",
2560 GST_ELEMENT_NAME (child), next,
2561 gst_element_state_get_name (next));
2562 have_no_preroll = TRUE;
2565 g_assert_not_reached ();
2568 g_value_reset (&data);
2571 case GST_ITERATOR_RESYNC:
2572 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2573 gst_iterator_resync (it);
2576 case GST_ITERATOR_DONE:
2577 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2583 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2584 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2587 if (have_no_preroll) {
2588 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2589 "we have NO_PREROLL elements %s -> NO_PREROLL",
2590 gst_element_state_change_return_get_name (ret));
2591 ret = GST_STATE_CHANGE_NO_PREROLL;
2592 } else if (have_async) {
2593 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2594 "we have ASYNC elements %s -> ASYNC",
2595 gst_element_state_change_return_get_name (ret));
2596 ret = GST_STATE_CHANGE_ASYNC;
2600 g_value_unset (&data);
2601 gst_iterator_free (it);
2603 GST_OBJECT_LOCK (bin);
2604 bin->polling = FALSE;
2605 /* it's possible that we did not get ASYNC from the children while the bin is
2606 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2607 * itself as the source. In that case we still want to check if the state
2608 * change completed. */
2609 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2610 /* no element returned ASYNC and there are no pending async_done messages,
2611 * we can just complete. */
2612 GST_DEBUG_OBJECT (bin, "no async elements");
2615 /* when we get here an ASYNC element was found */
2616 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2617 /* we ignore ASYNC state changes when we go to READY or NULL */
2618 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2619 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2623 GST_DEBUG_OBJECT (bin, "check async elements");
2624 /* check if all elements managed to commit their state already */
2625 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2626 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2627 * all the elements commited their state while we were doing the state
2628 * change. We will still return ASYNC for consistency but we commit the
2629 * state already so that a _get_state() will return immediately. */
2630 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2632 GST_DEBUG_OBJECT (bin, "async elements commited");
2633 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE, FALSE);
2637 bin->priv->pending_async_done = FALSE;
2638 GST_OBJECT_UNLOCK (bin);
2640 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2641 "done changing bin's state from %s to %s, now in %s, ret %s",
2642 gst_element_state_get_name (current),
2643 gst_element_state_get_name (next),
2644 gst_element_state_get_name (GST_STATE (element)),
2645 gst_element_state_change_return_get_name (ret));
2652 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2653 "failure (de)activating src pads");
2654 return GST_STATE_CHANGE_FAILURE;
2659 * This function is a utility event handler for seek events.
2660 * It will send the event to all sinks or sources depending on the
2663 * Applications are free to override this behaviour and
2664 * implement their own seek handler, but this will work for
2665 * pretty much all cases in practice.
2668 gst_bin_send_event (GstElement * element, GstEvent * event)
2670 GstBin *bin = GST_BIN_CAST (element);
2672 gboolean res = TRUE;
2673 gboolean done = FALSE;
2674 GValue data = { 0, };
2676 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2677 iter = gst_bin_iterate_sources (bin);
2678 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2679 GST_EVENT_TYPE_NAME (event));
2681 iter = gst_bin_iterate_sinks (bin);
2682 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2683 GST_EVENT_TYPE_NAME (event));
2687 switch (gst_iterator_next (iter, &data)) {
2688 case GST_ITERATOR_OK:
2690 GstElement *child = g_value_get_object (&data);;
2692 gst_event_ref (event);
2693 res &= gst_element_send_event (child, event);
2694 GST_LOG_OBJECT (child, "After handling %s event: %d",
2695 GST_EVENT_TYPE_NAME (event), res);
2698 case GST_ITERATOR_RESYNC:
2699 gst_iterator_resync (iter);
2702 case GST_ITERATOR_DONE:
2705 case GST_ITERATOR_ERROR:
2706 g_assert_not_reached ();
2710 g_value_unset (&data);
2711 gst_iterator_free (iter);
2712 gst_event_unref (event);
2717 /* this is the function called by the threadpool. When async elements commit
2718 * their state, this function will attempt to bring the bin to the next state.
2721 gst_bin_continue_func (BinContinueData * data)
2724 GstState current, next, pending;
2725 GstStateChange transition;
2728 pending = data->pending;
2730 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2731 GST_STATE_LOCK (bin);
2733 GST_DEBUG_OBJECT (bin, "doing state continue");
2734 GST_OBJECT_LOCK (bin);
2736 /* if a new state change happened after this thread was scheduled, we return
2738 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2741 current = GST_STATE (bin);
2742 next = GST_STATE_GET_NEXT (current, pending);
2743 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2745 GST_STATE_NEXT (bin) = next;
2746 GST_STATE_PENDING (bin) = pending;
2748 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2749 GST_OBJECT_UNLOCK (bin);
2751 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2752 "continue state change %s to %s, final %s",
2753 gst_element_state_get_name (current),
2754 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2756 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2758 GST_STATE_UNLOCK (bin);
2759 GST_DEBUG_OBJECT (bin, "state continue done");
2761 gst_object_unref (bin);
2762 g_slice_free (BinContinueData, data);
2767 GST_OBJECT_UNLOCK (bin);
2768 GST_STATE_UNLOCK (bin);
2769 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2770 gst_object_unref (bin);
2771 g_slice_free (BinContinueData, data);
2776 static GstBusSyncReply
2777 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2779 GstBinClass *bclass;
2781 bclass = GST_BIN_GET_CLASS (bin);
2782 if (bclass->handle_message)
2783 bclass->handle_message (bin, message);
2785 gst_message_unref (message);
2787 return GST_BUS_DROP;
2791 bin_push_state_continue (BinContinueData * data)
2798 klass = GST_BIN_GET_CLASS (bin);
2800 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2801 g_thread_pool_push (klass->pool, data, NULL);
2804 /* an element started an async state change, if we were not busy with a state
2805 * change, we perform a lost state.
2806 * This function is called with the OBJECT lock.
2809 bin_handle_async_start (GstBin * bin)
2811 GstState old_state, new_state;
2813 GstMessage *amessage = NULL;
2815 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2818 /* get our toplevel state */
2819 toplevel = BIN_IS_TOPLEVEL (bin);
2821 /* prepare an ASYNC_START message, we always post the start message even if we
2822 * are busy with a state change or when we are NO_PREROLL. */
2824 /* non toplevel bin, prepare async-start for the parent */
2825 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
2827 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2830 /* async starts are ignored when we are NO_PREROLL */
2831 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2832 goto was_no_preroll;
2834 old_state = GST_STATE (bin);
2836 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2837 * PLAYING after optionally redistributing the base_time. */
2838 if (old_state > GST_STATE_PAUSED)
2839 new_state = GST_STATE_PAUSED;
2841 new_state = old_state;
2843 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2844 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2845 gst_element_state_get_name (new_state));
2847 GST_STATE (bin) = new_state;
2848 GST_STATE_NEXT (bin) = new_state;
2849 GST_STATE_PENDING (bin) = new_state;
2850 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2851 GST_OBJECT_UNLOCK (bin);
2854 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2859 /* post our ASYNC_START. */
2860 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2861 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2863 GST_OBJECT_LOCK (bin);
2869 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2874 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2875 GST_OBJECT_UNLOCK (bin);
2880 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2881 GST_OBJECT_UNLOCK (bin);
2886 /* this function is called when there are no more async elements in the bin. We
2887 * post a state changed message and an ASYNC_DONE message.
2888 * This function is called with the OBJECT lock.
2891 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2892 gboolean flag_pending, gboolean reset_time)
2894 GstState current, pending, target;
2895 GstStateChangeReturn old_ret;
2896 GstState old_state, old_next;
2897 gboolean toplevel, state_changed = FALSE;
2898 GstMessage *amessage = NULL;
2899 BinContinueData *cont = NULL;
2901 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2904 pending = GST_STATE_PENDING (bin);
2909 /* check if there is something to commit */
2910 if (pending == GST_STATE_VOID_PENDING)
2911 goto nothing_pending;
2913 old_ret = GST_STATE_RETURN (bin);
2914 GST_STATE_RETURN (bin) = ret;
2916 /* move to the next target state */
2917 target = GST_STATE_TARGET (bin);
2918 pending = GST_STATE_PENDING (bin) = target;
2920 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), reset_time);
2922 old_state = GST_STATE (bin);
2923 /* this is the state we should go to next */
2924 old_next = GST_STATE_NEXT (bin);
2926 if (old_next != GST_STATE_PLAYING) {
2927 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2928 "committing state from %s to %s, old pending %s",
2929 gst_element_state_get_name (old_state),
2930 gst_element_state_get_name (old_next),
2931 gst_element_state_get_name (pending));
2933 /* update current state */
2934 current = GST_STATE (bin) = old_next;
2936 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2937 "setting state from %s to %s, pending %s",
2938 gst_element_state_get_name (old_state),
2939 gst_element_state_get_name (old_state),
2940 gst_element_state_get_name (pending));
2941 current = old_state;
2944 /* get our toplevel state */
2945 toplevel = BIN_IS_TOPLEVEL (bin);
2947 /* see if we reached the final state. If we are not toplevel, we also have to
2948 * stop here, the parent will continue our state. */
2949 if ((pending == current) || !toplevel) {
2950 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2951 "completed state change, pending VOID");
2953 /* mark VOID pending */
2954 pending = GST_STATE_VOID_PENDING;
2955 GST_STATE_PENDING (bin) = pending;
2956 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2958 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2959 "continue state change, pending %s",
2960 gst_element_state_get_name (pending));
2962 cont = g_slice_new (BinContinueData);
2964 /* ref to the bin */
2965 cont->bin = gst_object_ref (bin);
2966 /* cookie to detect concurrent state change */
2967 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2968 /* pending target state */
2969 cont->pending = pending;
2971 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2972 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2975 if (old_next != GST_STATE_PLAYING) {
2976 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2977 state_changed = TRUE;
2980 GST_OBJECT_UNLOCK (bin);
2982 if (state_changed) {
2983 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
2987 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2988 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
2989 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2992 GST_OBJECT_LOCK (bin);
2994 /* toplevel, start continue state */
2995 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
2996 bin_push_state_continue (cont);
2998 GST_DEBUG_OBJECT (bin, "state change complete");
2999 GST_STATE_BROADCAST (bin);
3005 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3010 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3011 /* if we were busy with a state change and we are requested to flag a
3012 * pending async done, we do so here */
3014 bin->priv->pending_async_done = TRUE;
3019 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3025 bin_do_eos (GstBin * bin)
3030 GST_OBJECT_LOCK (bin);
3031 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3032 * we forward the EOS message to the parent bin or application
3034 eos = GST_STATE (bin) == GST_STATE_PLAYING
3035 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3036 && is_eos (bin, &seqnum);
3037 GST_OBJECT_UNLOCK (bin);
3040 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3042 GstMessage *tmessage;
3043 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3044 gst_message_set_seqnum (tmessage, seqnum);
3045 GST_DEBUG_OBJECT (bin,
3046 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3047 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3051 /* must be called with the object lock. This function releases the lock to post
3054 bin_do_message_forward (GstBin * bin, GstMessage * message)
3056 if (bin->priv->message_forward) {
3057 GstMessage *forwarded;
3059 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3060 GST_MESSAGE_TYPE_NAME (message));
3061 GST_OBJECT_UNLOCK (bin);
3063 /* we need to convert these messages to element messages so that our parent
3064 * bin can easily ignore them and so that the application can easily
3065 * distinguish between the internally forwarded and the real messages. */
3066 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3067 gst_structure_new ("GstBinForwarded",
3068 "message", GST_TYPE_MESSAGE, message, NULL));
3070 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3072 GST_OBJECT_LOCK (bin);
3076 /* handle child messages:
3078 * This method is called synchronously when a child posts a message on
3081 * GST_MESSAGE_EOS: This message is only posted by sinks
3082 * in the PLAYING state. If all sinks posted the EOS message, post
3085 * GST_MESSAGE_STATE_DIRTY: Deprecated
3087 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3088 * element posts segment_start twice, only the last message is kept.
3090 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3091 * with the segment_done message. If there are no more segment_start
3092 * messages, post segment_done message upwards.
3094 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3095 * Whenever someone performs a duration query on the bin, we store the
3096 * result so we can answer it quicker the next time. Any element that
3097 * changes its duration marks our cached values invalid.
3098 * This message is also posted upwards. This is currently disabled
3099 * because too many elements don't post DURATION messages when the
3102 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3103 * can no longer provide a clock. The default bin behaviour is to
3104 * check if the lost clock was the one provided by the bin. If so and
3105 * we are currently in the PLAYING state, we forward the message to
3107 * This message is also generated when we remove a clock provider from
3108 * a bin. If this message is received by the application, it should
3109 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3110 * and a new base_time distribution.
3112 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3113 * can provide a clock. This mostly happens when we add a new clock
3114 * provider to the bin. The default behaviour of the bin is to mark the
3115 * currently selected clock as dirty, which will perform a clock
3116 * recalculation the next time we are asked to provide a clock.
3117 * This message is never sent to the application but is forwarded to
3120 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3121 * the state of the element and the fact that the element will need a
3122 * new base_time. This message is not forwarded to the application.
3124 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3125 * element when it posted ASYNC_START. If all elements are done, post a
3126 * ASYNC_DONE message to the parent.
3128 * OTHER: post upwards.
3131 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3134 GstMessageType type;
3135 GstMessage *tmessage;
3138 src = GST_MESSAGE_SRC (message);
3139 type = GST_MESSAGE_TYPE (message);
3141 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3142 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3143 GST_MESSAGE_TYPE_NAME (message));
3146 case GST_MESSAGE_ERROR:
3148 GST_OBJECT_LOCK (bin);
3150 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3151 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3152 GST_STATE_BROADCAST (bin);
3153 GST_OBJECT_UNLOCK (bin);
3157 case GST_MESSAGE_EOS:
3160 /* collect all eos messages from the children */
3161 GST_OBJECT_LOCK (bin);
3162 bin_do_message_forward (bin, message);
3163 /* ref message for future use */
3164 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3165 GST_OBJECT_UNLOCK (bin);
3170 case GST_MESSAGE_STATE_DIRTY:
3172 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3175 gst_message_unref (message);
3178 case GST_MESSAGE_SEGMENT_START:{
3179 gboolean post = FALSE;
3183 gst_message_parse_segment_start (message, &format, &position);
3184 seqnum = gst_message_get_seqnum (message);
3186 GST_OBJECT_LOCK (bin);
3187 bin_do_message_forward (bin, message);
3188 /* if this is the first segment-start, post to parent but not to the
3190 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3191 (GST_OBJECT_PARENT (bin) != NULL)) {
3194 /* replace any previous segment_start message from this source
3195 * with the new segment start message */
3196 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3197 GST_OBJECT_UNLOCK (bin);
3199 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3201 gst_message_set_seqnum (tmessage, seqnum);
3203 /* post segment start with initial format and position. */
3204 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3206 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3210 case GST_MESSAGE_SEGMENT_DONE:
3212 gboolean post = FALSE;
3216 gst_message_parse_segment_done (message, &format, &position);
3217 seqnum = gst_message_get_seqnum (message);
3219 GST_OBJECT_LOCK (bin);
3220 bin_do_message_forward (bin, message);
3221 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3222 /* if there are no more segment_start messages, everybody posted
3223 * a segment_done and we can post one on the bus. */
3225 /* we don't care who still has a pending segment start */
3226 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3229 /* remove all old segment_done messages */
3230 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3232 GST_OBJECT_UNLOCK (bin);
3234 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3236 gst_message_set_seqnum (tmessage, seqnum);
3238 /* post segment done with latest format and position. */
3239 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3241 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3245 case GST_MESSAGE_DURATION:
3247 /* remove all cached duration messages, next time somebody asks
3248 * for duration, we will recalculate. */
3249 GST_OBJECT_LOCK (bin);
3250 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3251 GST_OBJECT_UNLOCK (bin);
3254 case GST_MESSAGE_CLOCK_LOST:
3256 GstClock **provided_clock_p;
3257 GstElement **clock_provider_p;
3258 gboolean playing, provided, forward;
3261 gst_message_parse_clock_lost (message, &clock);
3263 GST_OBJECT_LOCK (bin);
3264 bin->clock_dirty = TRUE;
3265 /* if we lost the clock that we provided, post to parent but
3266 * only if we are PLAYING. */
3267 provided = (clock == bin->provided_clock);
3268 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3269 forward = playing & provided;
3271 GST_DEBUG_OBJECT (bin,
3272 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3273 bin->provided_clock, bin->clock_provider);
3274 provided_clock_p = &bin->provided_clock;
3275 clock_provider_p = &bin->clock_provider;
3276 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3277 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3279 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3280 provided, playing, forward);
3281 GST_OBJECT_UNLOCK (bin);
3287 gst_message_unref (message);
3290 case GST_MESSAGE_CLOCK_PROVIDE:
3294 GST_OBJECT_LOCK (bin);
3295 bin->clock_dirty = TRUE;
3296 /* a new clock is available, post to parent but not
3297 * to the application */
3298 forward = GST_OBJECT_PARENT (bin) != NULL;
3299 GST_OBJECT_UNLOCK (bin);
3305 gst_message_unref (message);
3308 case GST_MESSAGE_ASYNC_START:
3312 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3313 src ? GST_OBJECT_NAME (src) : "(NULL)");
3315 GST_OBJECT_LOCK (bin);
3316 bin_do_message_forward (bin, message);
3318 /* we ignore the message if we are going to <= READY */
3319 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3320 goto ignore_start_message;
3322 /* takes ownership of the message */
3323 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3325 bin_handle_async_start (bin);
3326 GST_OBJECT_UNLOCK (bin);
3329 ignore_start_message:
3331 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3332 gst_element_state_get_name (target));
3333 GST_OBJECT_UNLOCK (bin);
3334 gst_message_unref (message);
3338 case GST_MESSAGE_ASYNC_DONE:
3340 gboolean reset_time;
3343 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3344 src ? GST_OBJECT_NAME (src) : "(NULL)");
3346 gst_message_parse_async_done (message, &reset_time);
3348 GST_OBJECT_LOCK (bin);
3349 bin_do_message_forward (bin, message);
3351 /* ignore messages if we are shutting down */
3352 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3353 goto ignore_done_message;
3355 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3356 /* if there are no more ASYNC_START messages, everybody posted
3357 * a ASYNC_DONE and we can post one on the bus. When checking, we
3358 * don't care who still has a pending ASYNC_START */
3359 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3360 /* nothing found, remove all old ASYNC_DONE messages */
3361 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3363 GST_DEBUG_OBJECT (bin, "async elements commited");
3364 /* when we get an async done message when a state change was busy, we
3365 * need to set the pending_done flag so that at the end of the state
3366 * change we can see if we need to verify pending async elements, hence
3367 * the TRUE argument here. */
3368 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE, reset_time);
3370 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3372 GST_OBJECT_UNLOCK (bin);
3375 ignore_done_message:
3377 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3378 gst_element_state_get_name (target));
3379 GST_OBJECT_UNLOCK (bin);
3380 gst_message_unref (message);
3384 case GST_MESSAGE_STRUCTURE_CHANGE:
3388 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3390 GST_OBJECT_LOCK (bin);
3392 /* while the pad is busy, avoid following it when doing state changes.
3393 * Don't update the cookie yet, we will do that after the structure
3394 * change finished and we are ready to inspect the new updated
3396 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3399 /* a pad link/unlink ended, signal the state change iterator that we
3400 * need to resync by updating the structure_cookie. */
3401 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3402 GST_MESSAGE_STRUCTURE_CHANGE);
3403 bin->priv->structure_cookie++;
3405 GST_OBJECT_UNLOCK (bin);
3408 gst_message_unref (message);
3419 /* Send all other messages upward */
3420 GST_DEBUG_OBJECT (bin, "posting message upward");
3421 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3426 /* generic struct passed to all query fold methods */
3435 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3436 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3438 /* for duration/position we collect all durations/positions and take
3439 * the MAX of all valid results */
3441 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3449 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3451 GstElement *item = g_value_get_object (vitem);
3453 if (gst_element_query (item, fold->query)) {
3456 g_value_set_boolean (ret, TRUE);
3458 gst_query_parse_duration (fold->query, NULL, &duration);
3460 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3462 if (duration > fold->max)
3463 fold->max = duration;
3470 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3474 gst_query_parse_duration (fold->query, &format, NULL);
3475 /* store max in query result */
3476 gst_query_set_duration (fold->query, format, fold->max);
3478 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3481 GST_OBJECT_LOCK (bin);
3482 bin->messages = g_list_prepend (bin->messages,
3483 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3484 GST_OBJECT_UNLOCK (bin);
3488 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3490 GstElement *item = g_value_get_object (vitem);
3492 if (gst_element_query (item, fold->query)) {
3495 g_value_set_boolean (ret, TRUE);
3497 gst_query_parse_position (fold->query, NULL, &position);
3499 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3501 if (position > fold->max)
3502 fold->max = position;
3509 bin_query_position_done (GstBin * bin, QueryFold * fold)
3513 gst_query_parse_position (fold->query, &format, NULL);
3514 /* store max in query result */
3515 gst_query_set_position (fold->query, format, fold->max);
3517 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3521 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3523 GstElement *item = g_value_get_object (vitem);
3525 if (gst_element_query (item, fold->query)) {
3526 GstClockTime min, max;
3529 gst_query_parse_latency (fold->query, &live, &min, &max);
3531 GST_DEBUG_OBJECT (item,
3532 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3533 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3535 /* for the combined latency we collect the MAX of all min latencies and
3536 * the MIN of all max latencies */
3538 if (min > fold->min)
3540 if (fold->max == -1)
3542 else if (max < fold->max)
3544 if (fold->live == FALSE)
3548 g_value_set_boolean (ret, FALSE);
3549 GST_DEBUG_OBJECT (item, "failed query");
3556 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3558 /* store max in query result */
3559 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3561 GST_DEBUG_OBJECT (bin,
3562 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3563 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3567 /* generic fold, return first valid result */
3569 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3571 GstElement *item = g_value_get_object (vitem);
3574 if ((res = gst_element_query (item, fold->query))) {
3575 g_value_set_boolean (ret, TRUE);
3576 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3579 /* and stop as soon as we have a valid result */
3584 gst_bin_query (GstElement * element, GstQuery * query)
3586 GstBin *bin = GST_BIN_CAST (element);
3588 gboolean res = FALSE;
3589 GstIteratorFoldFunction fold_func;
3590 QueryInitFunction fold_init = NULL;
3591 QueryDoneFunction fold_done = NULL;
3592 QueryFold fold_data;
3595 switch (GST_QUERY_TYPE (query)) {
3596 case GST_QUERY_DURATION:
3601 gst_query_parse_duration (query, &qformat, NULL);
3603 /* find cached duration query */
3604 GST_OBJECT_LOCK (bin);
3605 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3606 GstMessage *message = (GstMessage *) cached->data;
3608 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3609 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3613 gst_message_parse_duration (message, &format, &duration);
3615 /* if cached same format, copy duration in query result */
3616 if (format == qformat) {
3617 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3619 GST_OBJECT_UNLOCK (bin);
3621 gst_query_set_duration (query, qformat, duration);
3627 GST_OBJECT_UNLOCK (bin);
3628 /* no cached value found, iterate and collect durations */
3629 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3630 fold_init = bin_query_min_max_init;
3631 fold_done = bin_query_duration_done;
3634 case GST_QUERY_POSITION:
3636 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3637 fold_init = bin_query_min_max_init;
3638 fold_done = bin_query_position_done;
3641 case GST_QUERY_LATENCY:
3643 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3644 fold_init = bin_query_min_max_init;
3645 fold_done = bin_query_latency_done;
3650 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3654 fold_data.query = query;
3656 /* set the result of the query to FALSE initially */
3657 g_value_init (&ret, G_TYPE_BOOLEAN);
3658 g_value_set_boolean (&ret, res);
3660 iter = gst_bin_iterate_sinks (bin);
3661 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3662 query, GST_QUERY_TYPE_NAME (query));
3665 fold_init (bin, &fold_data);
3668 GstIteratorResult ires;
3670 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3673 case GST_ITERATOR_RESYNC:
3674 gst_iterator_resync (iter);
3676 fold_init (bin, &fold_data);
3677 g_value_set_boolean (&ret, res);
3679 case GST_ITERATOR_OK:
3680 case GST_ITERATOR_DONE:
3681 res = g_value_get_boolean (&ret);
3682 if (fold_done != NULL && res)
3683 fold_done (bin, &fold_data);
3691 gst_iterator_free (iter);
3694 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3700 compare_name (const GValue * velement, const gchar * name)
3703 GstElement *element = g_value_get_object (velement);
3705 GST_OBJECT_LOCK (element);
3706 eq = strcmp (GST_ELEMENT_NAME (element), name);
3707 GST_OBJECT_UNLOCK (element);
3713 * gst_bin_get_by_name:
3715 * @name: the element name to search for
3717 * Gets the element with the given name from a bin. This
3718 * function recurses into child bins.
3720 * Returns NULL if no element with the given name is found in the bin.
3722 * MT safe. Caller owns returned reference.
3724 * Returns: (transfer full): the #GstElement with the given name, or NULL
3727 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3729 GstIterator *children;
3730 GValue result = { 0, };
3731 GstElement *element;
3734 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3736 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3737 GST_ELEMENT_NAME (bin), name);
3739 children = gst_bin_iterate_recurse (bin);
3740 found = gst_iterator_find_custom (children,
3741 (GCompareFunc) compare_name, &result, (gpointer) name);
3742 gst_iterator_free (children);
3745 element = g_value_dup_object (&result);
3746 g_value_unset (&result);
3755 * gst_bin_get_by_name_recurse_up:
3757 * @name: the element name to search for
3759 * Gets the element with the given name from this bin. If the
3760 * element is not found, a recursion is performed on the parent bin.
3763 * - no element with the given name is found in the bin
3765 * MT safe. Caller owns returned reference.
3767 * Returns: (transfer full): the #GstElement with the given name, or NULL
3770 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3774 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3775 g_return_val_if_fail (name != NULL, NULL);
3777 result = gst_bin_get_by_name (bin, name);
3782 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3784 if (GST_IS_BIN (parent)) {
3785 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3787 gst_object_unref (parent);
3795 compare_interface (const GValue * velement, GValue * interface)
3797 GstElement *element = g_value_get_object (velement);
3798 GType interface_type = (GType) g_value_get_pointer (interface);
3801 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3810 * gst_bin_get_by_interface:
3812 * @iface: the #GType of an interface
3814 * Looks for an element inside the bin that implements the given
3815 * interface. If such an element is found, it returns the element.
3816 * You can cast this element to the given interface afterwards. If you want
3817 * all elements that implement the interface, use
3818 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3820 * MT safe. Caller owns returned reference.
3822 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3825 gst_bin_get_by_interface (GstBin * bin, GType iface)
3827 GstIterator *children;
3828 GValue result = { 0, };
3829 GstElement *element;
3831 GValue viface = { 0, };
3833 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3834 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3836 g_value_init (&viface, G_TYPE_POINTER);
3837 g_value_set_pointer (&viface, (gpointer) iface);
3839 children = gst_bin_iterate_recurse (bin);
3840 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3842 gst_iterator_free (children);
3845 element = g_value_dup_object (&result);
3846 g_value_unset (&result);
3850 g_value_unset (&viface);
3856 * gst_bin_iterate_all_by_interface:
3858 * @iface: the #GType of an interface
3860 * Looks for all elements inside the bin that implements the given
3861 * interface. You can safely cast all returned elements to the given interface.
3862 * The function recurses inside child bins. The iterator will yield a series
3863 * of #GstElement that should be unreffed after use.
3865 * Each element yielded by the iterator will have its refcount increased, so
3868 * MT safe. Caller owns returned value.
3870 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3871 * in the bin implementing the given interface, or NULL
3874 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3876 GstIterator *children;
3877 GstIterator *result;
3878 GValue viface = { 0, };
3880 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3881 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3883 g_value_init (&viface, G_TYPE_POINTER);
3884 g_value_set_pointer (&viface, (gpointer) iface);
3886 children = gst_bin_iterate_recurse (bin);
3887 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3890 g_value_unset (&viface);