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 GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
226 GstState * state, GstState * pending, GstClockTime timeout);
227 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
228 gboolean flag_pending);
229 static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
230 static void bin_push_state_continue (BinContinueData * data);
231 static void bin_do_eos (GstBin * bin);
233 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
234 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
236 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
237 static GstIndex *gst_bin_get_index_func (GstElement * element);
239 static GstClock *gst_bin_provide_clock_func (GstElement * element);
240 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
242 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
243 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
244 static GstBusSyncReply bin_bus_handler (GstBus * bus,
245 GstMessage * message, GstBin * bin);
246 static gboolean gst_bin_query (GstElement * element, GstQuery ** query);
248 static gboolean gst_bin_do_latency_func (GstBin * bin);
250 static void bin_remove_messages (GstBin * bin, GstObject * src,
251 GstMessageType types);
252 static void gst_bin_continue_func (BinContinueData * data);
253 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
254 static gint bin_element_is_src (GstElement * child, GstBin * bin);
256 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
258 /* Bin signals and properties */
267 #define DEFAULT_ASYNC_HANDLING FALSE
268 #define DEFAULT_MESSAGE_FORWARD FALSE
274 PROP_MESSAGE_FORWARD,
278 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
280 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
284 const gchar *compat; \
285 static const GInterfaceInfo iface_info = { \
286 gst_bin_child_proxy_init, \
290 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
292 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
293 "debugging info for the 'bin' container element"); \
295 /* compatibility stuff */ \
296 compat = g_getenv ("GST_COMPAT"); \
297 if (compat != NULL) { \
298 if (strstr (compat, "no-live-preroll")) \
299 enable_latency = FALSE; \
300 else if (strstr (compat, "live-preroll")) \
301 enable_latency = TRUE; \
305 #define gst_bin_parent_class parent_class
306 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
309 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
315 bin = GST_BIN_CAST (child_proxy);
317 GST_OBJECT_LOCK (bin);
318 if ((res = g_list_nth_data (bin->children, index)))
319 gst_object_ref (res);
320 GST_OBJECT_UNLOCK (bin);
326 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
331 bin = GST_BIN_CAST (child_proxy);
333 GST_OBJECT_LOCK (bin);
334 num = bin->numchildren;
335 GST_OBJECT_UNLOCK (bin);
341 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
343 GstChildProxyInterface *iface = g_iface;
345 iface->get_children_count = gst_bin_child_proxy_get_children_count;
346 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
350 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
351 GValue * return_accu, const GValue * handler_return, gpointer dummy)
355 myboolean = g_value_get_boolean (handler_return);
356 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
357 g_value_set_boolean (return_accu, myboolean);
359 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
366 gst_bin_class_init (GstBinClass * klass)
368 GObjectClass *gobject_class;
369 GstObjectClass *gstobject_class;
370 GstElementClass *gstelement_class;
373 gobject_class = (GObjectClass *) klass;
374 gstobject_class = (GstObjectClass *) 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->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
472 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
473 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
474 gstelement_class->provide_clock =
475 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
476 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
478 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
479 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
481 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
482 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
483 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
485 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
487 GST_DEBUG ("creating bin thread pool");
490 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
492 g_critical ("could alloc threadpool %s", err->message);
497 gst_bin_init (GstBin * bin)
501 bin->numchildren = 0;
502 bin->children = NULL;
503 bin->children_cookie = 0;
504 bin->messages = NULL;
505 bin->provided_clock = NULL;
506 bin->clock_dirty = FALSE;
508 /* Set up a bus for listening to child elements */
509 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
510 bin->child_bus = bus;
511 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
513 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
515 bin->priv = GST_BIN_GET_PRIVATE (bin);
516 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
517 bin->priv->structure_cookie = 0;
518 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
522 gst_bin_dispose (GObject * object)
524 GstBin *bin = GST_BIN_CAST (object);
525 GstBus **child_bus_p = &bin->child_bus;
526 GstClock **provided_clock_p = &bin->provided_clock;
527 GstElement **clock_provider_p = &bin->clock_provider;
528 GstIndex **index_p = &bin->priv->index;
530 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
532 GST_OBJECT_LOCK (object);
533 gst_object_replace ((GstObject **) child_bus_p, NULL);
534 gst_object_replace ((GstObject **) provided_clock_p, NULL);
535 gst_object_replace ((GstObject **) clock_provider_p, NULL);
536 gst_object_replace ((GstObject **) index_p, NULL);
537 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
538 GST_OBJECT_UNLOCK (object);
540 while (bin->children) {
541 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
543 if (G_UNLIKELY (bin->children != NULL)) {
544 g_critical ("could not remove elements from bin '%s'",
545 GST_STR_NULL (GST_OBJECT_NAME (object)));
548 G_OBJECT_CLASS (parent_class)->dispose (object);
553 * @name: the name of the new bin
555 * Creates a new bin with the given name.
557 * Returns: (transfer full): a new #GstBin
560 gst_bin_new (const gchar * name)
562 return gst_element_factory_make ("bin", name);
566 gst_bin_set_property (GObject * object, guint prop_id,
567 const GValue * value, GParamSpec * pspec)
571 gstbin = GST_BIN_CAST (object);
574 case PROP_ASYNC_HANDLING:
575 GST_OBJECT_LOCK (gstbin);
576 gstbin->priv->asynchandling = g_value_get_boolean (value);
577 GST_OBJECT_UNLOCK (gstbin);
579 case PROP_MESSAGE_FORWARD:
580 GST_OBJECT_LOCK (gstbin);
581 gstbin->priv->message_forward = g_value_get_boolean (value);
582 GST_OBJECT_UNLOCK (gstbin);
585 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
591 gst_bin_get_property (GObject * object, guint prop_id,
592 GValue * value, GParamSpec * pspec)
596 gstbin = GST_BIN_CAST (object);
599 case PROP_ASYNC_HANDLING:
600 GST_OBJECT_LOCK (gstbin);
601 g_value_set_boolean (value, gstbin->priv->asynchandling);
602 GST_OBJECT_UNLOCK (gstbin);
604 case PROP_MESSAGE_FORWARD:
605 GST_OBJECT_LOCK (gstbin);
606 g_value_set_boolean (value, gstbin->priv->message_forward);
607 GST_OBJECT_UNLOCK (gstbin);
610 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
615 /* return the cached index */
617 gst_bin_get_index_func (GstElement * element)
622 bin = GST_BIN_CAST (element);
624 GST_OBJECT_LOCK (bin);
625 if ((result = bin->priv->index))
626 gst_object_ref (result);
627 GST_OBJECT_UNLOCK (bin);
632 /* set the index on all elements in this bin
637 gst_bin_set_index_func (GstElement * element, GstIndex * index)
643 GValue data = { 0, };
645 bin = GST_BIN_CAST (element);
647 GST_OBJECT_LOCK (bin);
648 old = bin->priv->index;
649 if (G_UNLIKELY (old == index))
652 gst_object_ref (index);
653 bin->priv->index = index;
654 GST_OBJECT_UNLOCK (bin);
657 gst_object_unref (old);
659 it = gst_bin_iterate_elements (bin);
661 /* set the index on all elements in the bin */
664 switch (gst_iterator_next (it, &data)) {
665 case GST_ITERATOR_OK:
667 GstElement *child = g_value_get_object (&data);
669 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
670 GST_ELEMENT_NAME (child));
671 gst_element_set_index (child, index);
673 g_value_reset (&data);
676 case GST_ITERATOR_RESYNC:
677 GST_DEBUG_OBJECT (bin, "iterator doing resync");
678 gst_iterator_resync (it);
681 case GST_ITERATOR_DONE:
682 GST_DEBUG_OBJECT (bin, "iterator done");
687 g_value_unset (&data);
688 gst_iterator_free (it);
693 GST_DEBUG_OBJECT (bin, "index was already set");
694 GST_OBJECT_UNLOCK (bin);
699 /* set the clock on all elements in this bin
704 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
710 GValue data = { 0, };
712 bin = GST_BIN_CAST (element);
714 it = gst_bin_iterate_elements (bin);
718 switch (gst_iterator_next (it, &data)) {
719 case GST_ITERATOR_OK:
721 GstElement *child = g_value_get_object (&data);
723 res &= gst_element_set_clock (child, clock);
725 g_value_reset (&data);
728 case GST_ITERATOR_RESYNC:
729 GST_DEBUG_OBJECT (bin, "iterator doing resync");
730 gst_iterator_resync (it);
734 case GST_ITERATOR_DONE:
735 GST_DEBUG_OBJECT (bin, "iterator done");
740 g_value_unset (&data);
741 gst_iterator_free (it);
746 /* get the clock for this bin by asking all of the children in this bin
748 * The ref of the returned clock in increased so unref after usage.
750 * We loop the elements in state order and pick the last clock we can
751 * get. This makes sure we get a clock from the source.
756 gst_bin_provide_clock_func (GstElement * element)
758 GstClock *result = NULL;
759 GstElement *provider = NULL;
764 GstClock **provided_clock_p;
765 GstElement **clock_provider_p;
767 bin = GST_BIN_CAST (element);
769 GST_OBJECT_LOCK (bin);
770 if (!bin->clock_dirty)
773 GST_DEBUG_OBJECT (bin, "finding new clock");
775 it = gst_bin_sort_iterator_new (bin);
776 GST_OBJECT_UNLOCK (bin);
780 switch (gst_iterator_next (it, &val)) {
781 case GST_ITERATOR_OK:
783 GstElement *child = g_value_get_object (&val);
786 clock = gst_element_provide_clock (child);
788 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
789 clock, GST_ELEMENT_NAME (child));
791 gst_object_unref (result);
792 gst_object_unref (provider);
795 provider = gst_object_ref (child);
798 g_value_reset (&val);
801 case GST_ITERATOR_RESYNC:
802 gst_iterator_resync (it);
805 case GST_ITERATOR_DONE:
810 g_value_unset (&val);
811 gst_iterator_free (it);
813 GST_OBJECT_LOCK (bin);
814 if (!bin->clock_dirty) {
816 gst_object_unref (provider);
818 gst_object_unref (result);
824 provided_clock_p = &bin->provided_clock;
825 clock_provider_p = &bin->clock_provider;
826 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
827 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
828 bin->clock_dirty = FALSE;
829 GST_DEBUG_OBJECT (bin,
830 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
832 /* Provider is not being returned to caller, just the result */
834 gst_object_unref (provider);
835 GST_OBJECT_UNLOCK (bin);
841 if ((result = bin->provided_clock))
842 gst_object_ref (result);
843 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
844 GST_OBJECT_UNLOCK (bin);
851 * functions for manipulating cached messages
856 GstMessageType types;
859 /* check if a message is of given src and type */
861 message_check (GstMessage * message, MessageFind * target)
866 eq &= GST_MESSAGE_SRC (message) == target->src;
868 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
869 GST_LOG ("looking at message %p: %d", message, eq);
875 find_message (GstBin * bin, GstObject * src, GstMessageType types)
883 result = g_list_find_custom (bin->messages, &find,
884 (GCompareFunc) message_check);
887 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
888 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
891 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
892 #ifndef GST_DISABLE_GST_DEBUG
896 for (i = 0; i < 32; i++)
897 if (types & (1 << i))
898 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
906 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
909 * A message that is cached and has the same SRC and type is replaced
910 * by the given message.
913 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
919 if ((src = GST_MESSAGE_SRC (message))) {
920 /* first find the previous message posted by this element */
921 if ((previous = find_message (bin, src, types))) {
922 GstMessage *previous_msg;
924 /* if we found a previous message, replace it */
925 previous_msg = previous->data;
926 previous->data = message;
928 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
929 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
930 GST_MESSAGE_TYPE_NAME (message));
932 gst_message_unref (previous_msg);
934 /* keep new message */
935 bin->messages = g_list_prepend (bin->messages, message);
937 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
938 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
941 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
942 GST_MESSAGE_TYPE_NAME (message));
944 gst_message_unref (message);
949 /* with LOCK. Remove all messages of given types */
951 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
959 for (walk = bin->messages; walk; walk = next) {
960 GstMessage *message = (GstMessage *) walk->data;
962 next = g_list_next (walk);
964 if (message_check (message, &find) == 0) {
965 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
966 "deleting message %p of types 0x%08x", message, types);
967 bin->messages = g_list_delete_link (bin->messages, walk);
968 gst_message_unref (message);
970 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
971 "not deleting message %p of type 0x%08x", message,
972 GST_MESSAGE_TYPE (message));
978 /* Check if the bin is EOS. We do this by scanning all sinks and
979 * checking if they posted an EOS message.
981 * call with bin LOCK */
983 is_eos (GstBin * bin, guint32 * seqnum)
989 for (walk = bin->children; walk; walk = g_list_next (walk)) {
992 element = GST_ELEMENT_CAST (walk->data);
993 if (bin_element_is_sink (element, bin) == 0) {
994 /* check if element posted EOS */
996 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
997 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
998 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1000 GST_DEBUG ("sink '%s' did not post EOS yet",
1001 GST_ELEMENT_NAME (element));
1011 unlink_pads (const GValue * item, gpointer user_data)
1016 pad = g_value_get_object (item);
1018 if ((peer = gst_pad_get_peer (pad))) {
1019 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1020 gst_pad_unlink (pad, peer);
1022 gst_pad_unlink (peer, pad);
1023 gst_object_unref (peer);
1027 /* vmethod that adds an element to a bin
1032 gst_bin_add_func (GstBin * bin, GstElement * element)
1036 gboolean is_sink, is_source;
1037 GstMessage *clock_message = NULL, *async_message = NULL;
1038 GstStateChangeReturn ret;
1040 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1042 /* we obviously can't add ourself to ourself */
1043 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1046 /* get the element name to make sure it is unique in this bin. */
1047 GST_OBJECT_LOCK (element);
1048 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1049 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1050 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1051 GST_OBJECT_UNLOCK (element);
1053 GST_OBJECT_LOCK (bin);
1055 /* then check to see if the element's name is already taken in the bin,
1056 * we can safely take the lock here. This check is probably bogus because
1057 * you can safely change the element name after this check and before setting
1058 * the object parent. The window is very small though... */
1059 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1060 goto duplicate_name;
1062 /* set the element's parent and add the element to the bin's list of children */
1063 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1064 GST_OBJECT_CAST (bin))))
1067 /* if we add a sink we become a sink */
1069 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1071 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1074 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1076 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1078 if (gst_element_provides_clock (element)) {
1079 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1081 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1084 bin->children = g_list_prepend (bin->children, element);
1086 bin->children_cookie++;
1087 bin->priv->structure_cookie++;
1089 /* distribute the bus */
1090 gst_element_set_bus (element, bin->child_bus);
1092 /* propagate the current base_time, start_time and clock */
1093 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1094 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1095 /* it's possible that the element did not accept the clock but
1096 * that is not important right now. When the pipeline goes to PLAYING,
1097 * a new clock will be selected */
1098 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1099 /* set the cached index on the children */
1100 if (bin->priv->index)
1101 gst_element_set_index (element, bin->priv->index);
1103 ret = GST_STATE_RETURN (bin);
1104 /* no need to update the state if we are in error */
1105 if (ret == GST_STATE_CHANGE_FAILURE)
1106 goto no_state_recalc;
1108 /* update the bin state, the new element could have been an ASYNC or
1109 * NO_PREROLL element */
1110 ret = GST_STATE_RETURN (element);
1111 GST_DEBUG_OBJECT (bin, "added %s element",
1112 gst_element_state_change_return_get_name (ret));
1115 case GST_STATE_CHANGE_ASYNC:
1117 /* create message to track this aync element when it posts an async-done
1120 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1123 case GST_STATE_CHANGE_NO_PREROLL:
1124 /* ignore all async elements we might have and commit our state */
1125 bin_handle_async_done (bin, ret, FALSE);
1127 case GST_STATE_CHANGE_FAILURE:
1134 GST_OBJECT_UNLOCK (bin);
1136 /* post the messages on the bus of the element so that the bin can handle
1139 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1142 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1144 /* unlink all linked pads */
1145 it = gst_element_iterate_pads (element);
1146 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1147 gst_iterator_free (it);
1149 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1153 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1154 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1158 /* ERROR handling here */
1161 GST_OBJECT_LOCK (bin);
1162 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1163 GST_OBJECT_UNLOCK (bin);
1168 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1169 elem_name, GST_ELEMENT_NAME (bin));
1170 GST_OBJECT_UNLOCK (bin);
1176 g_warning ("Element '%s' already has parent", elem_name);
1177 GST_OBJECT_UNLOCK (bin);
1186 * @element: (transfer full): the #GstElement to add
1188 * Adds the given element to the bin. Sets the element's parent, and thus
1189 * takes ownership of the element. An element can only be added to one bin.
1191 * If the element's pads are linked to other pads, the pads will be unlinked
1192 * before the element is added to the bin.
1195 * When you add an element to an already-running pipeline, you will have to
1196 * take care to set the state of the newly-added element to the desired
1197 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1198 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1199 * The bin or pipeline will not take care of this for you.
1204 * Returns: TRUE if the element could be added, FALSE if
1205 * the bin does not want to accept the element.
1208 gst_bin_add (GstBin * bin, GstElement * element)
1210 GstBinClass *bclass;
1213 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1214 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1216 bclass = GST_BIN_GET_CLASS (bin);
1218 if (G_UNLIKELY (bclass->add_element == NULL))
1221 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1222 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1223 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1225 result = bclass->add_element (bin, element);
1229 /* ERROR handling */
1232 g_warning ("adding elements to bin '%s' is not supported",
1233 GST_ELEMENT_NAME (bin));
1238 /* remove an element from the bin
1243 gst_bin_remove_func (GstBin * bin, GstElement * element)
1247 gboolean is_sink, is_source, othersink, othersource, found;
1248 GstMessage *clock_message = NULL;
1249 GstClock **provided_clock_p;
1250 GstElement **clock_provider_p;
1252 gboolean other_async, this_async, have_no_preroll;
1253 GstStateChangeReturn ret;
1255 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1257 GST_OBJECT_LOCK (element);
1258 /* Check if the element is already being removed and immediately
1260 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1261 goto already_removing;
1263 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1264 /* grab element name so we can print it */
1265 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1266 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1267 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1268 GST_OBJECT_UNLOCK (element);
1270 /* unlink all linked pads */
1271 it = gst_element_iterate_pads (element);
1272 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1273 gst_iterator_free (it);
1275 GST_OBJECT_LOCK (bin);
1278 othersource = FALSE;
1279 have_no_preroll = FALSE;
1280 /* iterate the elements, we collect which ones are async and no_preroll. We
1281 * also remove the element when we find it. */
1282 for (walk = bin->children; walk; walk = next) {
1283 GstElement *child = GST_ELEMENT_CAST (walk->data);
1285 next = g_list_next (walk);
1287 if (child == element) {
1289 /* remove the element */
1290 bin->children = g_list_delete_link (bin->children, walk);
1292 gboolean child_sink, child_source;
1294 GST_OBJECT_LOCK (child);
1295 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1296 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1297 /* when we remove a sink, check if there are other sinks. */
1298 if (is_sink && !othersink && child_sink)
1300 if (is_source && !othersource && child_source)
1302 /* check if we have NO_PREROLL children */
1303 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1304 have_no_preroll = TRUE;
1305 GST_OBJECT_UNLOCK (child);
1309 /* the element must have been in the bin's list of children */
1310 if (G_UNLIKELY (!found))
1313 /* we now removed the element from the list of elements, increment the cookie
1314 * so that others can detect a change in the children list. */
1316 bin->children_cookie++;
1317 bin->priv->structure_cookie++;
1319 if (is_sink && !othersink) {
1320 /* we're not a sink anymore */
1321 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1322 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1324 if (is_source && !othersource) {
1325 /* we're not a source anymore */
1326 GST_DEBUG_OBJECT (bin, "we removed the last source");
1327 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1331 /* if the clock provider for this element is removed, we lost
1332 * the clock as well, we need to inform the parent of this
1333 * so that it can select a new clock */
1334 if (bin->clock_provider == element) {
1335 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1336 bin->clock_dirty = TRUE;
1338 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1339 provided_clock_p = &bin->provided_clock;
1340 clock_provider_p = &bin->clock_provider;
1341 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1342 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1345 /* remove messages for the element, if there was a pending ASYNC_START
1346 * message we must see if removing the element caused the bin to lose its
1349 other_async = FALSE;
1350 for (walk = bin->messages; walk; walk = next) {
1351 GstMessage *message = (GstMessage *) walk->data;
1352 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1355 next = g_list_next (walk);
1358 switch (GST_MESSAGE_TYPE (message)) {
1359 case GST_MESSAGE_ASYNC_START:
1365 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1367 case GST_MESSAGE_STRUCTURE_CHANGE:
1371 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1373 /* it's unlikely that this message is still in the list of messages
1374 * because this would mean that a link/unlink is busy in another thread
1375 * while we remove the element. We still have to remove the message
1376 * because we might not receive the done message anymore when the element
1377 * is removed from the bin. */
1378 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1379 if (owner == element)
1390 /* delete all message types */
1391 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1392 message, elem_name);
1393 bin->messages = g_list_delete_link (bin->messages, walk);
1394 gst_message_unref (message);
1398 /* get last return */
1399 ret = GST_STATE_RETURN (bin);
1401 /* no need to update the state if we are in error */
1402 if (ret == GST_STATE_CHANGE_FAILURE)
1403 goto no_state_recalc;
1405 if (!other_async && this_async) {
1406 /* all other elements were not async and we removed the async one,
1407 * handle the async-done case because we are not async anymore now. */
1408 GST_DEBUG_OBJECT (bin,
1409 "we removed the last async element, have no_preroll %d",
1412 /* the current state return of the bin depends on if there are no_preroll
1413 * elements in the pipeline or not */
1414 if (have_no_preroll)
1415 ret = GST_STATE_CHANGE_NO_PREROLL;
1417 ret = GST_STATE_CHANGE_SUCCESS;
1419 bin_handle_async_done (bin, ret, FALSE);
1421 GST_DEBUG_OBJECT (bin,
1422 "recalc state preroll: %d, other async: %d, this async %d",
1423 have_no_preroll, other_async, this_async);
1425 if (have_no_preroll) {
1426 ret = GST_STATE_CHANGE_NO_PREROLL;
1427 } else if (other_async) {
1428 /* there are other async elements and we were not doing an async state
1429 * change, change our pending state and go async */
1430 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1431 GST_STATE_NEXT (bin) = GST_STATE (bin);
1432 GST_STATE_PENDING (bin) = GST_STATE (bin);
1434 ret = GST_STATE_CHANGE_ASYNC;
1436 GST_STATE_RETURN (bin) = ret;
1439 GST_OBJECT_UNLOCK (bin);
1442 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1444 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1448 gst_element_set_bus (element, NULL);
1450 /* Clear the clock we provided to the element */
1451 gst_element_set_clock (element, NULL);
1453 /* we ref here because after the _unparent() the element can be disposed
1454 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1455 gst_object_ref (element);
1456 gst_object_unparent (GST_OBJECT_CAST (element));
1458 GST_OBJECT_LOCK (element);
1459 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1460 GST_OBJECT_UNLOCK (element);
1462 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1463 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1465 /* element is really out of our control now */
1466 gst_object_unref (element);
1470 /* ERROR handling */
1473 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1474 GST_ELEMENT_NAME (bin));
1475 GST_OBJECT_UNLOCK (bin);
1481 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1482 GST_OBJECT_UNLOCK (element);
1490 * @element: (transfer none): the #GstElement to remove
1492 * Removes the element from the bin, unparenting it as well.
1493 * Unparenting the element means that the element will be dereferenced,
1494 * so if the bin holds the only reference to the element, the element
1495 * will be freed in the process of removing it from the bin. If you
1496 * want the element to still exist after removing, you need to call
1497 * gst_object_ref() before removing it from the bin.
1499 * If the element's pads are linked to other pads, the pads will be unlinked
1500 * before the element is removed from the bin.
1504 * Returns: TRUE if the element could be removed, FALSE if
1505 * the bin does not want to remove the element.
1508 gst_bin_remove (GstBin * bin, GstElement * element)
1510 GstBinClass *bclass;
1513 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1514 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1516 bclass = GST_BIN_GET_CLASS (bin);
1518 if (G_UNLIKELY (bclass->remove_element == NULL))
1521 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1522 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1524 result = bclass->remove_element (bin, element);
1528 /* ERROR handling */
1531 g_warning ("removing elements from bin '%s' is not supported",
1532 GST_ELEMENT_NAME (bin));
1538 * gst_bin_iterate_elements:
1541 * Gets an iterator for the elements in this bin.
1543 * Each element yielded by the iterator will have its refcount increased, so
1546 * MT safe. Caller owns returned value.
1548 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1551 gst_bin_iterate_elements (GstBin * bin)
1553 GstIterator *result;
1555 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1557 GST_OBJECT_LOCK (bin);
1558 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1559 GST_OBJECT_GET_LOCK (bin),
1560 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1561 GST_OBJECT_UNLOCK (bin);
1566 static GstIteratorItem
1567 iterate_child_recurse (GstIterator * it, const GValue * item)
1569 GstElement *child = g_value_get_object (item);
1571 if (GST_IS_BIN (child)) {
1572 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1574 gst_iterator_push (it, other);
1576 return GST_ITERATOR_ITEM_PASS;
1580 * gst_bin_iterate_recurse:
1583 * Gets an iterator for the elements in this bin.
1584 * This iterator recurses into GstBin children.
1586 * Each element yielded by the iterator will have its refcount increased, so
1589 * MT safe. Caller owns returned value.
1591 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1594 gst_bin_iterate_recurse (GstBin * bin)
1596 GstIterator *result;
1598 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1600 GST_OBJECT_LOCK (bin);
1601 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1602 GST_OBJECT_GET_LOCK (bin),
1603 &bin->children_cookie,
1605 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1606 GST_OBJECT_UNLOCK (bin);
1611 /* returns 0 when TRUE because this is a GCompareFunc */
1614 bin_element_is_sink (GstElement * child, GstBin * bin)
1618 /* we lock the child here for the remainder of the function to
1619 * get its name and flag safely. */
1620 GST_OBJECT_LOCK (child);
1621 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1623 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1624 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1626 GST_OBJECT_UNLOCK (child);
1627 return is_sink ? 0 : 1;
1631 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1633 GstBin *bin = g_value_get_object (vbin);
1634 GstElement *child = g_value_get_object (vchild);
1636 return (bin_element_is_sink (child, bin));
1640 * gst_bin_iterate_sinks:
1643 * Gets an iterator for all elements in the bin that have the
1644 * #GST_ELEMENT_IS_SINK flag set.
1646 * Each element yielded by the iterator will have its refcount increased, so
1649 * MT safe. Caller owns returned value.
1651 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1654 gst_bin_iterate_sinks (GstBin * bin)
1656 GstIterator *children;
1657 GstIterator *result;
1658 GValue vbin = { 0, };
1660 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1662 g_value_init (&vbin, GST_TYPE_BIN);
1663 g_value_set_object (&vbin, bin);
1665 children = gst_bin_iterate_elements (bin);
1666 result = gst_iterator_filter (children,
1667 (GCompareFunc) sink_iterator_filter, &vbin);
1669 g_value_unset (&vbin);
1674 /* returns 0 when TRUE because this is a GCompareFunc */
1677 bin_element_is_src (GstElement * child, GstBin * bin)
1681 /* we lock the child here for the remainder of the function to
1682 * get its name and other info safely. */
1683 GST_OBJECT_LOCK (child);
1684 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1686 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1687 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1689 GST_OBJECT_UNLOCK (child);
1690 return is_src ? 0 : 1;
1694 src_iterator_filter (const GValue * vchild, GValue * vbin)
1696 GstBin *bin = g_value_get_object (vbin);
1697 GstElement *child = g_value_get_object (vchild);
1699 return (bin_element_is_src (child, bin));
1703 * gst_bin_iterate_sources:
1706 * Gets an iterator for all elements in the bin that have the
1707 * #GST_ELEMENT_IS_SOURCE flag set.
1709 * Each element yielded by the iterator will have its refcount increased, so
1712 * MT safe. Caller owns returned value.
1714 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1717 gst_bin_iterate_sources (GstBin * bin)
1719 GstIterator *children;
1720 GstIterator *result;
1721 GValue vbin = { 0, };
1723 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1725 g_value_init (&vbin, GST_TYPE_BIN);
1726 g_value_set_object (&vbin, bin);
1728 children = gst_bin_iterate_elements (bin);
1729 result = gst_iterator_filter (children,
1730 (GCompareFunc) src_iterator_filter, &vbin);
1732 g_value_unset (&vbin);
1740 static GstStateChangeReturn
1741 gst_bin_get_state_func (GstElement * element, GstState * state,
1742 GstState * pending, GstClockTime timeout)
1744 GstStateChangeReturn ret;
1746 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1749 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1755 /***********************************************
1756 * Topologically sorted iterator
1757 * see http://en.wikipedia.org/wiki/Topological_sorting
1759 * For each element in the graph, an entry is kept in a HashTable
1760 * with its number of srcpad connections (degree).
1761 * We then change state of all elements without dependencies
1762 * (degree 0) and decrement the degree of all elements connected
1763 * on the sinkpads. When an element reaches degree 0, its state is
1765 * When all elements are handled the algorithm stops.
1767 typedef struct _GstBinSortIterator
1770 GQueue *queue; /* elements queued for state change */
1771 GstBin *bin; /* bin we iterate */
1772 gint mode; /* adding or removing dependency */
1773 GstElement *best; /* next element with least dependencies */
1774 gint best_deg; /* best degree */
1775 GHashTable *hash; /* hashtable with element dependencies */
1776 gboolean dirty; /* we detected structure change */
1777 } GstBinSortIterator;
1780 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1781 GstBinSortIterator * copy)
1783 GHashTableIter iter;
1784 gpointer key, value;
1786 copy->queue = g_queue_copy (it->queue);
1787 g_queue_foreach (copy->queue, (GFunc) gst_object_ref, NULL);
1789 copy->bin = gst_object_ref (it->bin);
1791 copy->best = gst_object_ref (it->best);
1793 copy->hash = g_hash_table_new (NULL, NULL);
1794 g_hash_table_iter_init (&iter, it->hash);
1795 while (g_hash_table_iter_next (&iter, &key, &value))
1796 g_hash_table_insert (copy->hash, key, value);
1799 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1800 #define HASH_SET_DEGREE(bit, elem, deg) \
1801 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1802 #define HASH_GET_DEGREE(bit, elem) \
1803 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1805 /* add element to queue of next elements in the iterator.
1806 * We push at the tail to give higher priority elements a
1809 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1811 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1812 GST_ELEMENT_NAME (element));
1813 gst_object_ref (element);
1814 g_queue_push_tail (bit->queue, element);
1815 HASH_SET_DEGREE (bit, element, -1);
1819 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1823 if ((find = g_queue_find (bit->queue, element))) {
1824 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1825 GST_ELEMENT_NAME (element));
1827 g_queue_delete_link (bit->queue, find);
1828 gst_object_unref (element);
1830 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1831 GST_ELEMENT_NAME (element));
1835 /* clear the queue, unref all objects as we took a ref when
1836 * we added them to the queue */
1838 clear_queue (GQueue * queue)
1842 while ((p = g_queue_pop_head (queue)))
1843 gst_object_unref (p);
1846 /* set all degrees to 0. Elements marked as a sink are
1847 * added to the queue immediatly. Since we only look at the SINK flag of the
1848 * element, it is possible that we add non-sinks to the queue. These will be
1849 * removed from the queue again when we can prove that it provides data for some
1852 reset_degree (GstElement * element, GstBinSortIterator * bit)
1856 /* sinks are added right away */
1857 GST_OBJECT_LOCK (element);
1858 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1859 GST_OBJECT_UNLOCK (element);
1862 add_to_queue (bit, element);
1864 /* others are marked with 0 and handled when sinks are done */
1865 HASH_SET_DEGREE (bit, element, 0);
1869 /* adjust the degree of all elements connected to the given
1870 * element. If a degree of an element drops to 0, it is
1871 * added to the queue of elements to schedule next.
1873 * We have to make sure not to cross the bin boundary this element
1877 update_degree (GstElement * element, GstBinSortIterator * bit)
1879 gboolean linked = FALSE;
1881 GST_OBJECT_LOCK (element);
1882 /* don't touch degree if element has no sinkpads */
1883 if (element->numsinkpads != 0) {
1884 /* loop over all sinkpads, decrement degree for all connected
1885 * elements in this bin */
1888 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1891 pad = GST_PAD_CAST (pads->data);
1893 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1894 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1895 GST_MESSAGE_STRUCTURE_CHANGE))) {
1896 /* mark the iterator as dirty because we won't be updating the degree
1897 * of the peer parent now. This would result in the 'loop detected'
1898 * later on because the peer parent element could become the best next
1899 * element with a degree > 0. We will simply continue our state
1900 * changes and we'll eventually resync when the unlink completed and
1901 * the iterator cookie is updated. */
1906 if ((peer = gst_pad_get_peer (pad))) {
1907 GstElement *peer_element;
1909 if ((peer_element = gst_pad_get_parent_element (peer))) {
1910 GST_OBJECT_LOCK (peer_element);
1911 /* check that we don't go outside of this bin */
1912 if (GST_OBJECT_CAST (peer_element)->parent ==
1913 GST_OBJECT_CAST (bit->bin)) {
1914 gint old_deg, new_deg;
1916 old_deg = HASH_GET_DEGREE (bit, peer_element);
1918 /* check to see if we added an element as sink that was not really a
1919 * sink because it was connected to some other element. */
1920 if (old_deg == -1) {
1921 remove_from_queue (bit, peer_element);
1924 new_deg = old_deg + bit->mode;
1926 GST_DEBUG_OBJECT (bit->bin,
1927 "change element %s, degree %d->%d, linked to %s",
1928 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1929 GST_ELEMENT_NAME (element));
1931 /* update degree, it is possible that an element was in 0 and
1932 * reaches -1 here. This would mean that the element had no sinkpads
1933 * but became linked while the state change was happening. We will
1934 * resync on this with the structure change message. */
1936 /* degree hit 0, add to queue */
1937 add_to_queue (bit, peer_element);
1939 HASH_SET_DEGREE (bit, peer_element, new_deg);
1943 GST_OBJECT_UNLOCK (peer_element);
1944 gst_object_unref (peer_element);
1946 gst_object_unref (peer);
1951 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1952 GST_ELEMENT_NAME (element));
1954 GST_OBJECT_UNLOCK (element);
1957 /* find the next best element not handled yet. This is the one
1958 * with the lowest non-negative degree */
1960 find_element (GstElement * element, GstBinSortIterator * bit)
1964 /* element is already handled */
1965 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1968 /* first element or element with smaller degree */
1969 if (bit->best == NULL || bit->best_deg > degree) {
1970 bit->best = element;
1971 bit->best_deg = degree;
1975 /* get next element in iterator. the returned element has the
1976 * refcount increased */
1977 static GstIteratorResult
1978 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
1981 GstBin *bin = bit->bin;
1983 /* empty queue, we have to find a next best element */
1984 if (g_queue_is_empty (bit->queue)) {
1987 bit->best_deg = G_MAXINT;
1988 g_list_foreach (bin->children, (GFunc) find_element, bit);
1989 if ((best = bit->best)) {
1990 /* when we detected an unlink, don't warn because our degrees might be
1991 * screwed up. We will resync later */
1992 if (bit->best_deg != 0 && !bit->dirty) {
1993 /* we don't fail on this one yet */
1994 GST_WARNING_OBJECT (bin, "loop dected in graph");
1995 g_warning ("loop detected in the graph of bin '%s'!!",
1996 GST_ELEMENT_NAME (bin));
1998 /* best unhandled element, schedule as next element */
1999 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2000 GST_ELEMENT_NAME (best));
2001 HASH_SET_DEGREE (bit, best, -1);
2002 g_value_set_object (result, best);
2004 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2005 /* no more unhandled elements, we are done */
2006 return GST_ITERATOR_DONE;
2009 /* everything added to the queue got reffed */
2010 best = g_queue_pop_head (bit->queue);
2011 g_value_set_object (result, best);
2012 gst_object_unref (best);
2015 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2016 /* update degrees of linked elements */
2017 update_degree (best, bit);
2019 return GST_ITERATOR_OK;
2022 /* clear queues, recalculate the degrees and restart. */
2024 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2026 GstBin *bin = bit->bin;
2028 GST_DEBUG_OBJECT (bin, "resync");
2030 clear_queue (bit->queue);
2032 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2033 /* calc degrees, incrementing */
2035 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2036 /* for the rest of the function we decrement the degrees */
2040 /* clear queues, unref bin and free iterator. */
2042 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2044 GstBin *bin = bit->bin;
2046 GST_DEBUG_OBJECT (bin, "free");
2047 clear_queue (bit->queue);
2048 g_queue_free (bit->queue);
2049 g_hash_table_destroy (bit->hash);
2050 gst_object_unref (bin);
2053 /* should be called with the bin LOCK held */
2054 static GstIterator *
2055 gst_bin_sort_iterator_new (GstBin * bin)
2057 GstBinSortIterator *result;
2059 /* we don't need an ItemFunction because we ref the items in the _next
2061 result = (GstBinSortIterator *)
2062 gst_iterator_new (sizeof (GstBinSortIterator),
2064 GST_OBJECT_GET_LOCK (bin),
2065 &bin->priv->structure_cookie,
2066 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2067 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2068 (GstIteratorItemFunction) NULL,
2069 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2070 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2071 result->queue = g_queue_new ();
2072 result->hash = g_hash_table_new (NULL, NULL);
2073 gst_object_ref (bin);
2075 gst_bin_sort_iterator_resync (result);
2077 return (GstIterator *) result;
2081 * gst_bin_iterate_sorted:
2084 * Gets an iterator for the elements in this bin in topologically
2085 * sorted order. This means that the elements are returned from
2086 * the most downstream elements (sinks) to the sources.
2088 * This function is used internally to perform the state changes
2089 * of the bin elements and for clock selection.
2091 * Each element yielded by the iterator will have its refcount increased, so
2094 * MT safe. Caller owns returned value.
2096 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2099 gst_bin_iterate_sorted (GstBin * bin)
2101 GstIterator *result;
2103 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2105 GST_OBJECT_LOCK (bin);
2106 result = gst_bin_sort_iterator_new (bin);
2107 GST_OBJECT_UNLOCK (bin);
2112 static GstStateChangeReturn
2113 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2114 GstClockTime base_time, GstClockTime start_time, GstState current,
2117 GstStateChangeReturn ret;
2118 GstState pending, child_current, child_pending;
2122 GST_STATE_LOCK (element);
2124 GST_OBJECT_LOCK (element);
2125 /* set base_time and start time on child */
2126 GST_ELEMENT_START_TIME (element) = start_time;
2127 element->base_time = base_time;
2128 /* peel off the locked flag */
2129 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2130 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2131 ret = GST_STATE_RETURN (element);
2132 child_current = GST_STATE (element);
2133 child_pending = GST_STATE_PENDING (element);
2134 GST_OBJECT_UNLOCK (element);
2136 /* skip locked elements */
2137 if (G_UNLIKELY (locked))
2140 /* if the element was no preroll, just start changing the state regardless
2141 * if it had async elements (in the case of a bin) because they won't preroll
2143 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2144 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2148 GST_OBJECT_LOCK (bin);
2149 pending = GST_STATE_PENDING (bin);
2151 /* Try not to change the state of elements that are already in the state we're
2153 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2154 (child_pending == GST_STATE_VOID_PENDING &&
2155 ((pending > child_current && next > child_current) ||
2156 (pending < child_current && next < child_current)))))
2159 /* the element was busy with an upwards async state change, we must wait for
2160 * an ASYNC_DONE message before we attemp to change the state. */
2162 find_message (bin, GST_OBJECT_CAST (element),
2163 GST_MESSAGE_ASYNC_START))) {
2164 #ifndef GST_DISABLE_GST_DEBUG
2165 GstMessage *message = GST_MESSAGE_CAST (found->data);
2167 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2168 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2170 /* only wait for upward state changes */
2171 if (next > current) {
2172 /* We found an async element check if we can force its state to change or
2173 * if we have to wait for it to preroll. */
2174 if (G_UNLIKELY (!enable_latency)) {
2175 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2176 "\tto preroll in order to perform correct latency calculations.\n"
2177 "\tPlease verify that the application continues to work correctly by\n"
2178 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2179 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2186 GST_OBJECT_UNLOCK (bin);
2189 GST_DEBUG_OBJECT (bin,
2190 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2191 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2192 GST_TIME_ARGS (base_time));
2195 ret = gst_element_set_state (element, next);
2197 GST_STATE_UNLOCK (element);
2203 GST_DEBUG_OBJECT (element,
2204 "element is locked, return previous return %s",
2205 gst_element_state_change_return_get_name (ret));
2206 GST_STATE_UNLOCK (element);
2211 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2212 GST_OBJECT_UNLOCK (bin);
2213 GST_STATE_UNLOCK (element);
2214 return GST_STATE_CHANGE_ASYNC;
2218 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2219 "skipping transition from %s to %s, since bin pending"
2220 " is %s : last change state return follows",
2221 gst_element_state_get_name (child_current),
2222 gst_element_state_get_name (next),
2223 gst_element_state_get_name (pending));
2224 GST_OBJECT_UNLOCK (bin);
2225 GST_STATE_UNLOCK (element);
2230 /* gst_iterator_fold functions for pads_activate
2231 * Stop the iterator if activating one pad failed. */
2233 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2235 GstPad *pad = g_value_get_object (vpad);
2236 gboolean cont = TRUE;
2238 if (!(cont = gst_pad_set_active (pad, *active)))
2239 g_value_set_boolean (ret, FALSE);
2241 /* unref the object that was reffed for us by _fold */
2245 /* returns false on error or early cutout of the fold, true if all
2246 * pads in @iter were (de)activated successfully. */
2248 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2250 GstIteratorResult ires;
2253 /* no need to unset this later, it's just a boolean */
2254 g_value_init (&ret, G_TYPE_BOOLEAN);
2255 g_value_set_boolean (&ret, TRUE);
2258 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2261 case GST_ITERATOR_RESYNC:
2262 /* need to reset the result again */
2263 g_value_set_boolean (&ret, TRUE);
2264 gst_iterator_resync (iter);
2266 case GST_ITERATOR_DONE:
2267 /* all pads iterated, return collected value */
2270 /* iterator returned _ERROR or premature end with _OK,
2271 * mark an error and exit */
2272 g_value_set_boolean (&ret, FALSE);
2277 /* return collected value */
2278 return g_value_get_boolean (&ret);
2281 /* is called with STATE_LOCK
2284 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2289 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2291 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2292 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2293 gst_iterator_free (iter);
2294 if (G_UNLIKELY (!fold_ok))
2297 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2304 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2310 * gst_bin_recalculate_latency:
2313 * Query @bin for the current latency using and reconfigures this latency to all the
2314 * elements with a LATENCY event.
2316 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2317 * is posted on the bus.
2319 * This function simply emits the 'do-latency' signal so any custom latency
2320 * calculations will be performed.
2322 * Returns: %TRUE if the latency could be queried and reconfigured.
2327 gst_bin_recalculate_latency (GstBin * bin)
2331 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2332 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2338 gst_bin_do_latency_func (GstBin * bin)
2341 GstElement *element;
2342 GstClockTime min_latency, max_latency;
2345 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2347 element = GST_ELEMENT_CAST (bin);
2349 GST_DEBUG_OBJECT (element, "querying latency");
2351 query = gst_query_new_latency ();
2352 if ((res = gst_element_query (element, &query))) {
2355 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2357 GST_DEBUG_OBJECT (element,
2358 "got min latency %" GST_TIME_FORMAT ", max latency %"
2359 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2360 GST_TIME_ARGS (max_latency), live);
2362 if (max_latency < min_latency) {
2363 /* this is an impossible situation, some parts of the pipeline might not
2364 * work correctly. We post a warning for now. */
2365 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2366 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2367 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2368 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2371 /* configure latency on elements */
2372 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2374 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2375 GST_TIME_ARGS (min_latency));
2377 GST_WARNING_OBJECT (element,
2378 "did not really configure latency of %" GST_TIME_FORMAT,
2379 GST_TIME_ARGS (min_latency));
2382 /* this is not a real problem, we just don't configure any latency. */
2383 GST_WARNING_OBJECT (element, "failed to query latency");
2385 gst_query_unref (query);
2390 static GstStateChangeReturn
2391 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2394 GstStateChangeReturn ret;
2395 GstState current, next;
2396 gboolean have_async;
2397 gboolean have_no_preroll;
2398 GstClockTime base_time, start_time;
2401 GValue data = { 0, };
2403 /* we don't need to take the STATE_LOCK, it is already taken */
2404 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2405 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2407 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2408 "changing state of children from %s to %s",
2409 gst_element_state_get_name (current), gst_element_state_get_name (next));
2411 bin = GST_BIN_CAST (element);
2414 case GST_STATE_PLAYING:
2418 GST_OBJECT_LOCK (bin);
2419 toplevel = BIN_IS_TOPLEVEL (bin);
2420 GST_OBJECT_UNLOCK (bin);
2423 gst_bin_recalculate_latency (bin);
2426 case GST_STATE_PAUSED:
2427 /* Clear EOS list on next PAUSED */
2428 GST_OBJECT_LOCK (bin);
2429 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2430 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2431 bin->priv->posted_eos = FALSE;
2432 GST_OBJECT_UNLOCK (bin);
2433 if (current == GST_STATE_READY)
2434 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2435 goto activate_failure;
2437 case GST_STATE_READY:
2438 /* Clear message list on next READY */
2439 GST_OBJECT_LOCK (bin);
2440 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2441 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2442 GST_OBJECT_UNLOCK (bin);
2443 if (current == GST_STATE_PAUSED)
2444 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2445 goto activate_failure;
2447 case GST_STATE_NULL:
2448 if (current == GST_STATE_READY)
2449 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2450 goto activate_failure;
2456 /* this flag is used to make the async state changes return immediatly. We
2457 * don't want them to interfere with this state change */
2458 GST_OBJECT_LOCK (bin);
2459 bin->polling = TRUE;
2460 GST_OBJECT_UNLOCK (bin);
2462 /* iterate in state change order */
2463 it = gst_bin_iterate_sorted (bin);
2465 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2466 * Note how we don't reset this value when a resync happens, the reason being
2467 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2468 * even after a resync when the async element is gone */
2472 /* take base_time */
2473 base_time = gst_element_get_base_time (element);
2474 start_time = gst_element_get_start_time (element);
2476 have_no_preroll = FALSE;
2480 switch (gst_iterator_next (it, &data)) {
2481 case GST_ITERATOR_OK:
2485 child = g_value_get_object (&data);
2487 /* set state and base_time now */
2488 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2492 case GST_STATE_CHANGE_SUCCESS:
2493 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2494 "child '%s' changed state to %d(%s) successfully",
2495 GST_ELEMENT_NAME (child), next,
2496 gst_element_state_get_name (next));
2498 case GST_STATE_CHANGE_ASYNC:
2500 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2501 "child '%s' is changing state asynchronously to %s",
2502 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2506 case GST_STATE_CHANGE_FAILURE:{
2509 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2510 "child '%s' failed to go to state %d(%s)",
2511 GST_ELEMENT_NAME (child),
2512 next, gst_element_state_get_name (next));
2514 /* Only fail if the child is still inside
2515 * this bin. It might've been removed already
2516 * because of the error by the bin subclass
2517 * to ignore the error. */
2518 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2519 if (parent == GST_OBJECT_CAST (element)) {
2520 /* element is still in bin, really error now */
2521 gst_object_unref (parent);
2524 /* child removed from bin, let the resync code redo the state
2526 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2527 "child '%s' was removed from the bin",
2528 GST_ELEMENT_NAME (child));
2531 gst_object_unref (parent);
2535 case GST_STATE_CHANGE_NO_PREROLL:
2536 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2537 "child '%s' changed state to %d(%s) successfully without preroll",
2538 GST_ELEMENT_NAME (child), next,
2539 gst_element_state_get_name (next));
2540 have_no_preroll = TRUE;
2543 g_assert_not_reached ();
2546 g_value_reset (&data);
2549 case GST_ITERATOR_RESYNC:
2550 GST_CAT_DEBUG (GST_CAT_STATES, "iterator doing resync");
2551 gst_iterator_resync (it);
2554 case GST_ITERATOR_DONE:
2555 GST_CAT_DEBUG (GST_CAT_STATES, "iterator done");
2561 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2562 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2565 if (have_no_preroll) {
2566 GST_CAT_DEBUG (GST_CAT_STATES,
2567 "we have NO_PREROLL elements %s -> NO_PREROLL",
2568 gst_element_state_change_return_get_name (ret));
2569 ret = GST_STATE_CHANGE_NO_PREROLL;
2570 } else if (have_async) {
2571 GST_CAT_DEBUG (GST_CAT_STATES, "we have ASYNC elements %s -> ASYNC",
2572 gst_element_state_change_return_get_name (ret));
2573 ret = GST_STATE_CHANGE_ASYNC;
2577 g_value_unset (&data);
2578 gst_iterator_free (it);
2580 GST_OBJECT_LOCK (bin);
2581 bin->polling = FALSE;
2582 /* it's possible that we did not get ASYNC from the children while the bin is
2583 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2584 * itself as the source. In that case we still want to check if the state
2585 * change completed. */
2586 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2587 /* no element returned ASYNC and there are no pending async_done messages,
2588 * we can just complete. */
2589 GST_DEBUG_OBJECT (bin, "no async elements");
2592 /* when we get here an ASYNC element was found */
2593 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2594 /* we ignore ASYNC state changes when we go to READY or NULL */
2595 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2596 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2600 GST_DEBUG_OBJECT (bin, "check async elements");
2601 /* check if all elements managed to commit their state already */
2602 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2603 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2604 * all the elements commited their state while we were doing the state
2605 * change. We will still return ASYNC for consistency but we commit the
2606 * state already so that a _get_state() will return immediatly. */
2607 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2609 GST_DEBUG_OBJECT (bin, "async elements commited");
2610 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2614 bin->priv->pending_async_done = FALSE;
2615 GST_OBJECT_UNLOCK (bin);
2617 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2618 "done changing bin's state from %s to %s, now in %s, ret %s",
2619 gst_element_state_get_name (current),
2620 gst_element_state_get_name (next),
2621 gst_element_state_get_name (GST_STATE (element)),
2622 gst_element_state_change_return_get_name (ret));
2631 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2632 "failure (de)activating src pads");
2633 return GST_STATE_CHANGE_FAILURE;
2638 * This function is a utility event handler for seek events.
2639 * It will send the event to all sinks or sources depending on the
2642 * Applications are free to override this behaviour and
2643 * implement their own seek handler, but this will work for
2644 * pretty much all cases in practice.
2647 gst_bin_send_event (GstElement * element, GstEvent * event)
2649 GstBin *bin = GST_BIN_CAST (element);
2651 gboolean res = TRUE;
2652 gboolean done = FALSE;
2653 GValue data = { 0, };
2655 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2656 iter = gst_bin_iterate_sources (bin);
2657 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2658 GST_EVENT_TYPE_NAME (event));
2660 iter = gst_bin_iterate_sinks (bin);
2661 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2662 GST_EVENT_TYPE_NAME (event));
2666 switch (gst_iterator_next (iter, &data)) {
2667 case GST_ITERATOR_OK:
2669 GstElement *child = g_value_get_object (&data);;
2671 gst_event_ref (event);
2672 res &= gst_element_send_event (child, event);
2673 g_value_reset (&data);
2676 case GST_ITERATOR_RESYNC:
2677 gst_iterator_resync (iter);
2680 case GST_ITERATOR_DONE:
2683 case GST_ITERATOR_ERROR:
2684 g_assert_not_reached ();
2688 g_value_unset (&data);
2689 gst_iterator_free (iter);
2690 gst_event_unref (event);
2695 /* this is the function called by the threadpool. When async elements commit
2696 * their state, this function will attempt to bring the bin to the next state.
2699 gst_bin_continue_func (BinContinueData * data)
2702 GstState current, next, pending;
2703 GstStateChange transition;
2706 pending = data->pending;
2708 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2709 GST_STATE_LOCK (bin);
2711 GST_DEBUG_OBJECT (bin, "doing state continue");
2712 GST_OBJECT_LOCK (bin);
2714 /* if a new state change happened after this thread was scheduled, we return
2716 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2719 current = GST_STATE (bin);
2720 next = GST_STATE_GET_NEXT (current, pending);
2721 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2723 GST_STATE_NEXT (bin) = next;
2724 GST_STATE_PENDING (bin) = pending;
2726 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2727 GST_OBJECT_UNLOCK (bin);
2729 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2730 "continue state change %s to %s, final %s",
2731 gst_element_state_get_name (current),
2732 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2734 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2736 GST_STATE_UNLOCK (bin);
2737 GST_DEBUG_OBJECT (bin, "state continue done");
2741 gst_object_unref (bin);
2742 g_slice_free (BinContinueData, data);
2747 GST_OBJECT_UNLOCK (bin);
2748 GST_STATE_UNLOCK (bin);
2749 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2750 gst_object_unref (bin);
2751 g_slice_free (BinContinueData, data);
2756 static GstBusSyncReply
2757 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2759 GstBinClass *bclass;
2761 bclass = GST_BIN_GET_CLASS (bin);
2762 if (bclass->handle_message)
2763 bclass->handle_message (bin, message);
2765 gst_message_unref (message);
2767 return GST_BUS_DROP;
2771 bin_push_state_continue (BinContinueData * data)
2778 klass = GST_BIN_GET_CLASS (bin);
2780 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2781 g_thread_pool_push (klass->pool, data, NULL);
2784 /* an element started an async state change, if we were not busy with a state
2785 * change, we perform a lost state.
2786 * This function is called with the OBJECT lock.
2789 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2791 GstState old_state, new_state;
2793 GstMessage *amessage = NULL;
2795 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2798 /* get our toplevel state */
2799 toplevel = BIN_IS_TOPLEVEL (bin);
2801 /* prepare an ASYNC_START message, we always post the start message even if we
2802 * are busy with a state change or when we are NO_PREROLL. */
2804 /* non toplevel bin, prepare async-start for the parent */
2806 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2808 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2811 /* async starts are ignored when we are NO_PREROLL */
2812 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2813 goto was_no_preroll;
2815 old_state = GST_STATE (bin);
2817 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2818 * PLAYING after optionally redistributing the base_time. */
2819 if (old_state > GST_STATE_PAUSED)
2820 new_state = GST_STATE_PAUSED;
2822 new_state = old_state;
2824 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2825 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2826 gst_element_state_get_name (new_state));
2828 GST_STATE (bin) = new_state;
2829 GST_STATE_NEXT (bin) = new_state;
2830 GST_STATE_PENDING (bin) = new_state;
2831 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2832 GST_OBJECT_UNLOCK (bin);
2835 gst_element_post_message (GST_ELEMENT_CAST (bin),
2836 gst_message_new_state_changed (GST_OBJECT_CAST (bin),
2837 new_state, new_state, new_state));
2841 /* post our ASYNC_START. */
2842 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2843 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2845 GST_OBJECT_LOCK (bin);
2851 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2856 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2857 GST_OBJECT_UNLOCK (bin);
2862 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2863 GST_OBJECT_UNLOCK (bin);
2868 /* this function is called when there are no more async elements in the bin. We
2869 * post a state changed message and an ASYNC_DONE message.
2870 * This function is called with the OBJECT lock.
2873 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2874 gboolean flag_pending)
2876 GstState current, pending, target;
2877 GstStateChangeReturn old_ret;
2878 GstState old_state, old_next;
2880 GstMessage *smessage = NULL, *amessage = NULL;
2881 BinContinueData *cont = NULL;
2883 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2886 pending = GST_STATE_PENDING (bin);
2891 /* check if there is something to commit */
2892 if (pending == GST_STATE_VOID_PENDING)
2893 goto nothing_pending;
2895 old_ret = GST_STATE_RETURN (bin);
2896 GST_STATE_RETURN (bin) = ret;
2898 /* move to the next target state */
2899 target = GST_STATE_TARGET (bin);
2900 pending = GST_STATE_PENDING (bin) = target;
2902 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2904 old_state = GST_STATE (bin);
2905 /* this is the state we should go to next */
2906 old_next = GST_STATE_NEXT (bin);
2908 if (old_next != GST_STATE_PLAYING) {
2909 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2910 "committing state from %s to %s, old pending %s",
2911 gst_element_state_get_name (old_state),
2912 gst_element_state_get_name (old_next),
2913 gst_element_state_get_name (pending));
2915 /* update current state */
2916 current = GST_STATE (bin) = old_next;
2918 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2919 "setting state from %s to %s, pending %s",
2920 gst_element_state_get_name (old_state),
2921 gst_element_state_get_name (old_state),
2922 gst_element_state_get_name (pending));
2923 current = old_state;
2926 /* get our toplevel state */
2927 toplevel = BIN_IS_TOPLEVEL (bin);
2929 /* see if we reached the final state. If we are not toplevel, we also have to
2930 * stop here, the parent will continue our state. */
2931 if ((pending == current) || !toplevel) {
2932 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2933 "completed state change, pending VOID");
2935 /* mark VOID pending */
2936 pending = GST_STATE_VOID_PENDING;
2937 GST_STATE_PENDING (bin) = pending;
2938 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2940 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2941 "continue state change, pending %s",
2942 gst_element_state_get_name (pending));
2944 cont = g_slice_new (BinContinueData);
2946 /* ref to the bin */
2947 cont->bin = gst_object_ref (bin);
2948 /* cookie to detect concurrent state change */
2949 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2950 /* pending target state */
2951 cont->pending = pending;
2953 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2954 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2957 if (old_next != GST_STATE_PLAYING) {
2958 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2959 smessage = gst_message_new_state_changed (GST_OBJECT_CAST (bin),
2960 old_state, old_next, pending);
2963 GST_OBJECT_UNLOCK (bin);
2966 GST_DEBUG_OBJECT (bin, "posting state change message");
2967 gst_element_post_message (GST_ELEMENT_CAST (bin), smessage);
2970 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2971 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
2972 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2978 GST_OBJECT_LOCK (bin);
2980 /* toplevel, start continue state */
2981 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
2982 bin_push_state_continue (cont);
2984 GST_DEBUG_OBJECT (bin, "state change complete");
2985 GST_STATE_BROADCAST (bin);
2991 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2996 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2997 /* if we were busy with a state change and we are requested to flag a
2998 * pending async done, we do so here */
3000 bin->priv->pending_async_done = TRUE;
3005 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3011 bin_do_eos (GstBin * bin)
3016 GST_OBJECT_LOCK (bin);
3017 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3018 * we forward the EOS message to the parent bin or application
3020 eos = GST_STATE (bin) == GST_STATE_PLAYING
3021 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3022 && is_eos (bin, &seqnum);
3023 GST_OBJECT_UNLOCK (bin);
3026 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3028 GstMessage *tmessage;
3029 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3030 gst_message_set_seqnum (tmessage, seqnum);
3031 GST_DEBUG_OBJECT (bin,
3032 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3033 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3037 /* must be called with the object lock. This function releases the lock to post
3040 bin_do_message_forward (GstBin * bin, GstMessage * message)
3042 if (bin->priv->message_forward) {
3043 GstMessage *forwarded;
3045 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3046 GST_MESSAGE_TYPE_NAME (message));
3047 GST_OBJECT_UNLOCK (bin);
3049 /* we need to convert these messages to element messages so that our parent
3050 * bin can easily ignore them and so that the application can easily
3051 * distinguish between the internally forwarded and the real messages. */
3052 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3053 gst_structure_new ("GstBinForwarded",
3054 "message", GST_TYPE_MESSAGE, message, NULL));
3056 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3058 GST_OBJECT_LOCK (bin);
3062 /* handle child messages:
3064 * This method is called synchronously when a child posts a message on
3067 * GST_MESSAGE_EOS: This message is only posted by sinks
3068 * in the PLAYING state. If all sinks posted the EOS message, post
3071 * GST_MESSAGE_STATE_DIRTY: Deprecated
3073 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3074 * element posts segment_start twice, only the last message is kept.
3076 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3077 * with the segment_done message. If there are no more segment_start
3078 * messages, post segment_done message upwards.
3080 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3081 * Whenever someone performs a duration query on the bin, we store the
3082 * result so we can answer it quicker the next time. Any element that
3083 * changes its duration marks our cached values invalid.
3084 * This message is also posted upwards. This is currently disabled
3085 * because too many elements don't post DURATION messages when the
3088 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3089 * can no longer provide a clock. The default bin behaviour is to
3090 * check if the lost clock was the one provided by the bin. If so and
3091 * we are currently in the PLAYING state, we forward the message to
3093 * This message is also generated when we remove a clock provider from
3094 * a bin. If this message is received by the application, it should
3095 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3096 * and a new base_time distribution.
3098 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3099 * can provide a clock. This mostly happens when we add a new clock
3100 * provider to the bin. The default behaviour of the bin is to mark the
3101 * currently selected clock as dirty, which will perform a clock
3102 * recalculation the next time we are asked to provide a clock.
3103 * This message is never sent to the application but is forwarded to
3106 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3107 * the state of the element and the fact that the element will need a
3108 * new base_time. This message is not forwarded to the application.
3110 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3111 * element when it posted ASYNC_START. If all elements are done, post a
3112 * ASYNC_DONE message to the parent.
3114 * OTHER: post upwards.
3117 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3120 GstMessageType type;
3121 GstMessage *tmessage;
3124 src = GST_MESSAGE_SRC (message);
3125 type = GST_MESSAGE_TYPE (message);
3127 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3128 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3129 GST_MESSAGE_TYPE_NAME (message));
3132 case GST_MESSAGE_ERROR:
3134 GST_OBJECT_LOCK (bin);
3136 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3137 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3138 GST_STATE_BROADCAST (bin);
3139 GST_OBJECT_UNLOCK (bin);
3143 case GST_MESSAGE_EOS:
3146 /* collect all eos messages from the children */
3147 GST_OBJECT_LOCK (bin);
3148 bin_do_message_forward (bin, message);
3149 /* ref message for future use */
3150 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3151 GST_OBJECT_UNLOCK (bin);
3156 case GST_MESSAGE_STATE_DIRTY:
3158 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3161 gst_message_unref (message);
3164 case GST_MESSAGE_SEGMENT_START:{
3165 gboolean post = FALSE;
3169 gst_message_parse_segment_start (message, &format, &position);
3170 seqnum = gst_message_get_seqnum (message);
3172 GST_OBJECT_LOCK (bin);
3173 bin_do_message_forward (bin, message);
3174 /* if this is the first segment-start, post to parent but not to the
3176 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3177 (GST_OBJECT_PARENT (bin) != NULL)) {
3180 /* replace any previous segment_start message from this source
3181 * with the new segment start message */
3182 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3183 GST_OBJECT_UNLOCK (bin);
3185 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3187 gst_message_set_seqnum (tmessage, seqnum);
3189 /* post segment start with initial format and position. */
3190 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3192 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3196 case GST_MESSAGE_SEGMENT_DONE:
3198 gboolean post = FALSE;
3202 gst_message_parse_segment_done (message, &format, &position);
3203 seqnum = gst_message_get_seqnum (message);
3205 GST_OBJECT_LOCK (bin);
3206 bin_do_message_forward (bin, message);
3207 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3208 /* if there are no more segment_start messages, everybody posted
3209 * a segment_done and we can post one on the bus. */
3211 /* we don't care who still has a pending segment start */
3212 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3215 /* remove all old segment_done messages */
3216 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3218 GST_OBJECT_UNLOCK (bin);
3220 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3222 gst_message_set_seqnum (tmessage, seqnum);
3224 /* post segment done with latest format and position. */
3225 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3227 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3231 case GST_MESSAGE_DURATION:
3233 /* remove all cached duration messages, next time somebody asks
3234 * for duration, we will recalculate. */
3235 GST_OBJECT_LOCK (bin);
3236 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3237 GST_OBJECT_UNLOCK (bin);
3240 case GST_MESSAGE_CLOCK_LOST:
3242 GstClock **provided_clock_p;
3243 GstElement **clock_provider_p;
3244 gboolean playing, provided, forward;
3247 gst_message_parse_clock_lost (message, &clock);
3249 GST_OBJECT_LOCK (bin);
3250 bin->clock_dirty = TRUE;
3251 /* if we lost the clock that we provided, post to parent but
3252 * only if we are PLAYING. */
3253 provided = (clock == bin->provided_clock);
3254 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3255 forward = playing & provided;
3257 GST_DEBUG_OBJECT (bin,
3258 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3259 bin->provided_clock, bin->clock_provider);
3260 provided_clock_p = &bin->provided_clock;
3261 clock_provider_p = &bin->clock_provider;
3262 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3263 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3265 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3266 provided, playing, forward);
3267 GST_OBJECT_UNLOCK (bin);
3273 gst_message_unref (message);
3276 case GST_MESSAGE_CLOCK_PROVIDE:
3280 GST_OBJECT_LOCK (bin);
3281 bin->clock_dirty = TRUE;
3282 /* a new clock is available, post to parent but not
3283 * to the application */
3284 forward = GST_OBJECT_PARENT (bin) != NULL;
3285 GST_OBJECT_UNLOCK (bin);
3291 gst_message_unref (message);
3294 case GST_MESSAGE_ASYNC_START:
3296 gboolean new_base_time;
3299 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3300 src ? GST_OBJECT_NAME (src) : "(NULL)");
3302 gst_message_parse_async_start (message, &new_base_time);
3304 GST_OBJECT_LOCK (bin);
3305 bin_do_message_forward (bin, message);
3307 /* we ignore the message if we are going to <= READY */
3308 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3309 goto ignore_start_message;
3311 /* takes ownership of the message */
3312 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3314 bin_handle_async_start (bin, new_base_time);
3315 GST_OBJECT_UNLOCK (bin);
3318 ignore_start_message:
3320 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3321 gst_element_state_get_name (target));
3322 GST_OBJECT_UNLOCK (bin);
3323 gst_message_unref (message);
3327 case GST_MESSAGE_ASYNC_DONE:
3331 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3332 src ? GST_OBJECT_NAME (src) : "(NULL)");
3334 GST_OBJECT_LOCK (bin);
3335 bin_do_message_forward (bin, message);
3337 /* ignore messages if we are shutting down */
3338 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3339 goto ignore_done_message;
3341 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3342 /* if there are no more ASYNC_START messages, everybody posted
3343 * a ASYNC_DONE and we can post one on the bus. When checking, we
3344 * don't care who still has a pending ASYNC_START */
3345 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3346 /* nothing found, remove all old ASYNC_DONE messages */
3347 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3349 GST_DEBUG_OBJECT (bin, "async elements commited");
3350 /* when we get an async done message when a state change was busy, we
3351 * need to set the pending_done flag so that at the end of the state
3352 * change we can see if we need to verify pending async elements, hence
3353 * the TRUE argument here. */
3354 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3356 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3358 GST_OBJECT_UNLOCK (bin);
3361 ignore_done_message:
3363 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3364 gst_element_state_get_name (target));
3365 GST_OBJECT_UNLOCK (bin);
3366 gst_message_unref (message);
3370 case GST_MESSAGE_STRUCTURE_CHANGE:
3374 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3376 GST_OBJECT_LOCK (bin);
3378 /* while the pad is busy, avoid following it when doing state changes.
3379 * Don't update the cookie yet, we will do that after the structure
3380 * change finished and we are ready to inspect the new updated
3382 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3385 /* a pad link/unlink ended, signal the state change iterator that we
3386 * need to resync by updating the structure_cookie. */
3387 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3388 GST_MESSAGE_STRUCTURE_CHANGE);
3389 bin->priv->structure_cookie++;
3391 GST_OBJECT_UNLOCK (bin);
3394 gst_message_unref (message);
3405 /* Send all other messages upward */
3406 GST_DEBUG_OBJECT (bin, "posting message upward");
3407 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3412 /* generic struct passed to all query fold methods */
3421 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3422 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3424 /* for duration/position we collect all durations/positions and take
3425 * the MAX of all valid results */
3427 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3435 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3437 GstElement *item = g_value_get_object (vitem);
3439 if (gst_element_query (item, fold->query)) {
3442 g_value_set_boolean (ret, TRUE);
3444 gst_query_parse_duration (*fold->query, NULL, &duration);
3446 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3448 if (duration > fold->max)
3449 fold->max = duration;
3456 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3460 gst_query_parse_duration (*fold->query, &format, NULL);
3461 *fold->query = gst_query_make_writable (*fold->query);
3462 /* store max in query result */
3463 gst_query_set_duration (*fold->query, format, fold->max);
3465 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3468 GST_OBJECT_LOCK (bin);
3469 bin->messages = g_list_prepend (bin->messages,
3470 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3471 GST_OBJECT_UNLOCK (bin);
3475 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3477 GstElement *item = g_value_get_object (vitem);
3479 if (gst_element_query (item, fold->query)) {
3482 g_value_set_boolean (ret, TRUE);
3484 gst_query_parse_position (*fold->query, NULL, &position);
3486 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3488 if (position > fold->max)
3489 fold->max = position;
3496 bin_query_position_done (GstBin * bin, QueryFold * fold)
3500 gst_query_parse_position (*fold->query, &format, NULL);
3501 *fold->query = gst_query_make_writable (*fold->query);
3502 /* store max in query result */
3503 gst_query_set_position (*fold->query, format, fold->max);
3505 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3509 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3511 GstElement *item = g_value_get_object (vitem);
3513 if (gst_element_query (item, fold->query)) {
3514 GstClockTime min, max;
3517 gst_query_parse_latency (*fold->query, &live, &min, &max);
3519 GST_DEBUG_OBJECT (item,
3520 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3521 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3523 /* for the combined latency we collect the MAX of all min latencies and
3524 * the MIN of all max latencies */
3526 if (min > fold->min)
3528 if (fold->max == -1)
3530 else if (max < fold->max)
3532 if (fold->live == FALSE)
3536 g_value_set_boolean (ret, FALSE);
3537 GST_DEBUG_OBJECT (item, "failed query");
3544 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3546 /* store max in query result */
3547 *fold->query = gst_query_make_writable (*fold->query);
3548 gst_query_set_latency (*fold->query, fold->live, fold->min, fold->max);
3550 GST_DEBUG_OBJECT (bin,
3551 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3552 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3556 /* generic fold, return first valid result */
3558 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3560 GstElement *item = g_value_get_object (vitem);
3563 if ((res = gst_element_query (item, fold->query))) {
3564 g_value_set_boolean (ret, TRUE);
3565 GST_DEBUG_OBJECT (item, "answered query %" GST_PTR_FORMAT, *fold->query);
3568 /* and stop as soon as we have a valid result */
3573 gst_bin_query (GstElement * element, GstQuery ** query)
3575 GstBin *bin = GST_BIN_CAST (element);
3577 gboolean res = FALSE;
3578 GstIteratorFoldFunction fold_func;
3579 QueryInitFunction fold_init = NULL;
3580 QueryDoneFunction fold_done = NULL;
3581 QueryFold fold_data;
3584 switch (GST_QUERY_TYPE (*query)) {
3585 case GST_QUERY_DURATION:
3590 gst_query_parse_duration (*query, &qformat, NULL);
3592 /* find cached duration query */
3593 GST_OBJECT_LOCK (bin);
3594 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3595 GstMessage *message = (GstMessage *) cached->data;
3597 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3598 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3602 gst_message_parse_duration (message, &format, &duration);
3604 /* if cached same format, copy duration in query result */
3605 if (format == qformat) {
3606 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3608 GST_OBJECT_UNLOCK (bin);
3610 *query = gst_query_make_writable (*query);
3611 gst_query_set_duration (*query, qformat, duration);
3617 GST_OBJECT_UNLOCK (bin);
3618 /* no cached value found, iterate and collect durations */
3619 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3620 fold_init = bin_query_min_max_init;
3621 fold_done = bin_query_duration_done;
3624 case GST_QUERY_POSITION:
3626 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3627 fold_init = bin_query_min_max_init;
3628 fold_done = bin_query_position_done;
3631 case GST_QUERY_LATENCY:
3633 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3634 fold_init = bin_query_min_max_init;
3635 fold_done = bin_query_latency_done;
3640 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3644 fold_data.query = query;
3646 /* set the result of the query to FALSE initially */
3647 g_value_init (&ret, G_TYPE_BOOLEAN);
3648 g_value_set_boolean (&ret, res);
3650 iter = gst_bin_iterate_sinks (bin);
3651 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3652 query, GST_QUERY_TYPE_NAME (*query));
3655 fold_init (bin, &fold_data);
3658 GstIteratorResult ires;
3660 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3663 case GST_ITERATOR_RESYNC:
3664 gst_iterator_resync (iter);
3666 fold_init (bin, &fold_data);
3667 g_value_set_boolean (&ret, res);
3669 case GST_ITERATOR_OK:
3670 case GST_ITERATOR_DONE:
3671 res = g_value_get_boolean (&ret);
3672 if (fold_done != NULL && res)
3673 fold_done (bin, &fold_data);
3681 gst_iterator_free (iter);
3684 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3690 compare_name (const GValue * velement, const gchar * name)
3693 GstElement *element = g_value_get_object (velement);
3695 GST_OBJECT_LOCK (element);
3696 eq = strcmp (GST_ELEMENT_NAME (element), name);
3697 GST_OBJECT_UNLOCK (element);
3703 * gst_bin_get_by_name:
3705 * @name: the element name to search for
3707 * Gets the element with the given name from a bin. This
3708 * function recurses into child bins.
3710 * Returns NULL if no element with the given name is found in the bin.
3712 * MT safe. Caller owns returned reference.
3714 * Returns: (transfer full): the #GstElement with the given name, or NULL
3717 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3719 GstIterator *children;
3720 GValue result = { 0, };
3721 GstElement *element;
3724 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3726 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3727 GST_ELEMENT_NAME (bin), name);
3729 children = gst_bin_iterate_recurse (bin);
3730 found = gst_iterator_find_custom (children,
3731 (GCompareFunc) compare_name, &result, (gpointer) name);
3732 gst_iterator_free (children);
3735 element = g_value_dup_object (&result);
3736 g_value_unset (&result);
3745 * gst_bin_get_by_name_recurse_up:
3747 * @name: the element name to search for
3749 * Gets the element with the given name from this bin. If the
3750 * element is not found, a recursion is performed on the parent bin.
3753 * - no element with the given name is found in the bin
3755 * MT safe. Caller owns returned reference.
3757 * Returns: (transfer full): the #GstElement with the given name, or NULL
3760 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3764 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3765 g_return_val_if_fail (name != NULL, NULL);
3767 result = gst_bin_get_by_name (bin, name);
3772 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3774 if (GST_IS_BIN (parent)) {
3775 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3777 gst_object_unref (parent);
3785 compare_interface (const GValue * velement, GValue * interface)
3787 GstElement *element = g_value_get_object (velement);
3788 GType interface_type = (GType) g_value_get_pointer (interface);
3791 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3800 * gst_bin_get_by_interface:
3802 * @iface: the #GType of an interface
3804 * Looks for an element inside the bin that implements the given
3805 * interface. If such an element is found, it returns the element.
3806 * You can cast this element to the given interface afterwards. If you want
3807 * all elements that implement the interface, use
3808 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3810 * MT safe. Caller owns returned reference.
3812 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3815 gst_bin_get_by_interface (GstBin * bin, GType iface)
3817 GstIterator *children;
3818 GValue result = { 0, };
3819 GstElement *element;
3821 GValue viface = { 0, };
3823 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3824 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3826 g_value_init (&viface, G_TYPE_POINTER);
3827 g_value_set_pointer (&viface, (gpointer) iface);
3829 children = gst_bin_iterate_recurse (bin);
3830 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3832 gst_iterator_free (children);
3835 element = g_value_dup_object (&result);
3836 g_value_unset (&result);
3840 g_value_unset (&viface);
3846 * gst_bin_iterate_all_by_interface:
3848 * @iface: the #GType of an interface
3850 * Looks for all elements inside the bin that implements the given
3851 * interface. You can safely cast all returned elements to the given interface.
3852 * The function recurses inside child bins. The iterator will yield a series
3853 * of #GstElement that should be unreffed after use.
3855 * Each element yielded by the iterator will have its refcount increased, so
3858 * MT safe. Caller owns returned value.
3860 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3861 * in the bin implementing the given interface, or NULL
3864 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3866 GstIterator *children;
3867 GstIterator *result;
3868 GValue viface = { 0, };
3870 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3871 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3873 g_value_init (&viface, G_TYPE_POINTER);
3874 g_value_set_pointer (&viface, (gpointer) iface);
3876 children = gst_bin_iterate_recurse (bin);
3877 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3880 g_value_unset (&viface);