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"
167 #include "gsterror.h"
169 #include "gstindex.h"
170 #include "gstindexfactory.h"
171 #include "gstutils.h"
172 #include "gstchildproxy.h"
174 #ifdef GST_DISABLE_DEPRECATED
175 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
177 #define GstXmlNodePtr xmlNodePtr
178 #include <libxml/parser.h>
179 GstXmlNodePtr gst_object_save_thyself (GstObject * object,
180 GstXmlNodePtr parent);
181 void gst_object_restore_thyself (GstObject * object, GstXmlNodePtr parent);
182 GstElement *gst_xml_make_element (xmlNodePtr cur, GstObject * parent);
186 /* enable for DURATION caching.
187 * FIXME currently too many elements don't update
188 * their duration when it changes so we return inaccurate values. */
189 #undef DURATION_CACHING
191 /* latency is by default enabled now.
192 * live-preroll and no-live-preroll in the environment var GST_COMPAT
193 * to enables or disable it respectively.
195 static gboolean enable_latency = TRUE;
197 GST_DEBUG_CATEGORY_STATIC (bin_debug);
198 #define GST_CAT_DEFAULT bin_debug
200 /* a bin is toplevel if it has no parent or when it is configured to behave like
202 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
204 #define GST_BIN_GET_PRIVATE(obj) \
205 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
207 struct _GstBinPrivate
209 gboolean asynchandling;
210 /* if we get an ASYNC_DONE message from ourselves, this means that the
211 * subclass will simulate ASYNC behaviour without having ASYNC children. When
212 * such an ASYNC_DONE message is posted while we are doing a state change, we
213 * have to process the message after finishing the state change even when no
214 * child returned GST_STATE_CHANGE_ASYNC. */
215 gboolean pending_async_done;
217 guint32 structure_cookie;
221 /* forward messages from our children */
222 gboolean message_forward;
234 static void gst_bin_dispose (GObject * object);
236 static void gst_bin_set_property (GObject * object, guint prop_id,
237 const GValue * value, GParamSpec * pspec);
238 static void gst_bin_get_property (GObject * object, guint prop_id,
239 GValue * value, GParamSpec * pspec);
241 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
242 GstStateChange transition);
243 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
244 GstState newstate, GstState pending);
245 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
246 GstState * state, GstState * pending, GstClockTime timeout);
247 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
248 gboolean flag_pending);
249 static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
250 static void bin_push_state_continue (BinContinueData * data);
251 static void bin_do_eos (GstBin * bin);
253 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
254 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
256 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
257 static GstIndex *gst_bin_get_index_func (GstElement * element);
259 static GstClock *gst_bin_provide_clock_func (GstElement * element);
260 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
262 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
263 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
264 static GstBusSyncReply bin_bus_handler (GstBus * bus,
265 GstMessage * message, GstBin * bin);
266 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
268 static gboolean gst_bin_do_latency_func (GstBin * bin);
270 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
271 static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
272 static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
275 static void bin_remove_messages (GstBin * bin, GstObject * src,
276 GstMessageType types);
277 static void gst_bin_continue_func (BinContinueData * data);
278 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
279 static gint bin_element_is_src (GstElement * child, GstBin * bin);
281 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
283 /* Bin signals and properties */
292 #define DEFAULT_ASYNC_HANDLING FALSE
293 #define DEFAULT_MESSAGE_FORWARD FALSE
299 PROP_MESSAGE_FORWARD,
303 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
305 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
307 #define _do_init(type) \
309 const gchar *compat; \
310 static const GInterfaceInfo iface_info = { \
311 gst_bin_child_proxy_init, \
315 g_type_add_interface_static (type, GST_TYPE_CHILD_PROXY, &iface_info); \
317 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
318 "debugging info for the 'bin' container element"); \
320 /* compatibility stuff */ \
321 compat = g_getenv ("GST_COMPAT"); \
322 if (compat != NULL) { \
323 if (strstr (compat, "no-live-preroll")) \
324 enable_latency = FALSE; \
325 else if (strstr (compat, "live-preroll")) \
326 enable_latency = TRUE; \
330 GST_BOILERPLATE_FULL (GstBin, gst_bin, GstElement, GST_TYPE_ELEMENT, _do_init);
333 gst_bin_base_init (gpointer g_class)
335 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
337 gst_element_class_set_details_simple (gstelement_class, "Generic bin",
339 "Simple container object",
340 "Erik Walthinsen <omega@cse.ogi.edu>,"
341 "Wim Taymans <wim.taymans@gmail.com>");
345 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
351 bin = GST_BIN_CAST (child_proxy);
353 GST_OBJECT_LOCK (bin);
354 if ((res = g_list_nth_data (bin->children, index)))
355 gst_object_ref (res);
356 GST_OBJECT_UNLOCK (bin);
362 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
367 bin = GST_BIN_CAST (child_proxy);
369 GST_OBJECT_LOCK (bin);
370 num = bin->numchildren;
371 GST_OBJECT_UNLOCK (bin);
377 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
379 GstChildProxyInterface *iface = g_iface;
381 iface->get_children_count = gst_bin_child_proxy_get_children_count;
382 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
386 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
387 GValue * return_accu, const GValue * handler_return, gpointer dummy)
391 myboolean = g_value_get_boolean (handler_return);
392 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
393 g_value_set_boolean (return_accu, myboolean);
395 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
402 gst_bin_class_init (GstBinClass * klass)
404 GObjectClass *gobject_class = (GObjectClass *) klass;
405 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
406 GstObjectClass *gstobject_class = (GstObjectClass *) klass;
408 GstElementClass *gstelement_class = (GstElementClass *) klass;
411 g_type_class_add_private (klass, sizeof (GstBinPrivate));
413 gobject_class->set_property = gst_bin_set_property;
414 gobject_class->get_property = gst_bin_get_property;
417 * GstBin:async-handling
419 * If set to #TRUE, the bin will handle asynchronous state changes.
420 * This should be used only if the bin subclass is modifying the state
421 * of its children on its own.
425 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
426 g_param_spec_boolean ("async-handling", "Async Handling",
427 "The bin will handle Asynchronous state changes",
428 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
431 * GstBin::element-added:
433 * @element: the #GstElement that was added to the bin
435 * Will be emitted after the element was added to the bin.
437 gst_bin_signals[ELEMENT_ADDED] =
438 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
439 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
440 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
442 * GstBin::element-removed:
444 * @element: the #GstElement that was removed from the bin
446 * Will be emitted after the element was removed from the bin.
448 gst_bin_signals[ELEMENT_REMOVED] =
449 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
450 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
451 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
453 * GstBin::do-latency:
456 * Will be emitted when the bin needs to perform latency calculations. This
457 * signal is only emited for toplevel bins or when async-handling is
460 * Only one signal handler is invoked. If no signals are connected, the
461 * default handler is invoked, which will query and distribute the lowest
462 * possible latency to all sinks.
464 * Connect to this signal if the default latency calculations are not
465 * sufficient, like when you need different latencies for different sinks in
470 gst_bin_signals[DO_LATENCY] =
471 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
472 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
473 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
474 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
477 * GstBin:message-forward
479 * Forward all children messages, even those that would normally be filtered by
480 * the bin. This can be interesting when one wants to be notified of the EOS
481 * state of individual elements, for example.
483 * The messages are converted to an ELEMENT message with the bin as the
484 * source. The structure of the message is named 'GstBinForwarded' and contains
485 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
490 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
491 g_param_spec_boolean ("message-forward", "Message Forward",
492 "Forwards all children messages",
493 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
495 gobject_class->dispose = gst_bin_dispose;
497 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
498 gstobject_class->save_thyself =
499 ((gpointer (*)(GstObject * object,
500 gpointer self)) * GST_DEBUG_FUNCPTR (gst_bin_save_thyself));
501 gstobject_class->restore_thyself =
502 ((void (*)(GstObject * object,
503 gpointer self)) *GST_DEBUG_FUNCPTR (gst_bin_restore_thyself));
506 gstelement_class->change_state =
507 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
508 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
509 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
510 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
511 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
512 gstelement_class->provide_clock =
513 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
514 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
516 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
517 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
519 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
520 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
521 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
523 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
525 GST_DEBUG ("creating bin thread pool");
528 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
530 g_critical ("could alloc threadpool %s", err->message);
535 gst_bin_init (GstBin * bin, GstBinClass * klass)
539 bin->numchildren = 0;
540 bin->children = NULL;
541 bin->children_cookie = 0;
542 bin->messages = NULL;
543 bin->provided_clock = NULL;
544 bin->clock_dirty = FALSE;
546 /* Set up a bus for listening to child elements */
547 bus = gst_bus_new ();
548 bin->child_bus = bus;
549 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
551 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
553 bin->priv = GST_BIN_GET_PRIVATE (bin);
554 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
555 bin->priv->structure_cookie = 0;
556 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
560 gst_bin_dispose (GObject * object)
562 GstBin *bin = GST_BIN_CAST (object);
563 GstBus **child_bus_p = &bin->child_bus;
564 GstClock **provided_clock_p = &bin->provided_clock;
565 GstElement **clock_provider_p = &bin->clock_provider;
566 GstIndex **index_p = &bin->priv->index;
568 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
570 GST_OBJECT_LOCK (object);
571 gst_object_replace ((GstObject **) child_bus_p, NULL);
572 gst_object_replace ((GstObject **) provided_clock_p, NULL);
573 gst_object_replace ((GstObject **) clock_provider_p, NULL);
574 gst_object_replace ((GstObject **) index_p, NULL);
575 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
576 GST_OBJECT_UNLOCK (object);
578 while (bin->children) {
579 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
581 if (G_UNLIKELY (bin->children != NULL)) {
582 g_critical ("could not remove elements from bin '%s'",
583 GST_STR_NULL (GST_OBJECT_NAME (object)));
586 G_OBJECT_CLASS (parent_class)->dispose (object);
591 * @name: the name of the new bin
593 * Creates a new bin with the given name.
595 * Returns: (transfer full): a new #GstBin
598 gst_bin_new (const gchar * name)
600 return gst_element_factory_make ("bin", name);
604 gst_bin_set_property (GObject * object, guint prop_id,
605 const GValue * value, GParamSpec * pspec)
609 gstbin = GST_BIN_CAST (object);
612 case PROP_ASYNC_HANDLING:
613 GST_OBJECT_LOCK (gstbin);
614 gstbin->priv->asynchandling = g_value_get_boolean (value);
615 GST_OBJECT_UNLOCK (gstbin);
617 case PROP_MESSAGE_FORWARD:
618 GST_OBJECT_LOCK (gstbin);
619 gstbin->priv->message_forward = g_value_get_boolean (value);
620 GST_OBJECT_UNLOCK (gstbin);
623 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
629 gst_bin_get_property (GObject * object, guint prop_id,
630 GValue * value, GParamSpec * pspec)
634 gstbin = GST_BIN_CAST (object);
637 case PROP_ASYNC_HANDLING:
638 GST_OBJECT_LOCK (gstbin);
639 g_value_set_boolean (value, gstbin->priv->asynchandling);
640 GST_OBJECT_UNLOCK (gstbin);
642 case PROP_MESSAGE_FORWARD:
643 GST_OBJECT_LOCK (gstbin);
644 g_value_set_boolean (value, gstbin->priv->message_forward);
645 GST_OBJECT_UNLOCK (gstbin);
648 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
653 /* return the cached index */
655 gst_bin_get_index_func (GstElement * element)
660 bin = GST_BIN_CAST (element);
662 GST_OBJECT_LOCK (bin);
663 if ((result = bin->priv->index))
664 gst_object_ref (result);
665 GST_OBJECT_UNLOCK (bin);
670 /* set the index on all elements in this bin
675 gst_bin_set_index_func (GstElement * element, GstIndex * index)
682 bin = GST_BIN_CAST (element);
684 GST_OBJECT_LOCK (bin);
685 old = bin->priv->index;
686 if (G_UNLIKELY (old == index))
689 gst_object_ref (index);
690 bin->priv->index = index;
691 GST_OBJECT_UNLOCK (bin);
694 gst_object_unref (old);
696 it = gst_bin_iterate_elements (bin);
698 /* set the index on all elements in the bin */
703 switch (gst_iterator_next (it, &data)) {
704 case GST_ITERATOR_OK:
706 GstElement *child = GST_ELEMENT_CAST (data);
708 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
709 GST_ELEMENT_NAME (child));
710 gst_element_set_index (child, index);
712 gst_object_unref (child);
715 case GST_ITERATOR_RESYNC:
716 GST_DEBUG_OBJECT (bin, "iterator doing resync");
717 gst_iterator_resync (it);
720 case GST_ITERATOR_DONE:
721 GST_DEBUG_OBJECT (bin, "iterator done");
726 gst_iterator_free (it);
731 GST_DEBUG_OBJECT (bin, "index was already set");
732 GST_OBJECT_UNLOCK (bin);
737 /* set the clock on all elements in this bin
742 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
749 bin = GST_BIN_CAST (element);
751 it = gst_bin_iterate_elements (bin);
757 switch (gst_iterator_next (it, &data)) {
758 case GST_ITERATOR_OK:
760 GstElement *child = GST_ELEMENT_CAST (data);
762 res &= gst_element_set_clock (child, clock);
764 gst_object_unref (child);
767 case GST_ITERATOR_RESYNC:
768 GST_DEBUG_OBJECT (bin, "iterator doing resync");
769 gst_iterator_resync (it);
773 case GST_ITERATOR_DONE:
774 GST_DEBUG_OBJECT (bin, "iterator done");
779 gst_iterator_free (it);
784 /* get the clock for this bin by asking all of the children in this bin
786 * The ref of the returned clock in increased so unref after usage.
788 * We loop the elements in state order and pick the last clock we can
789 * get. This makes sure we get a clock from the source.
794 gst_bin_provide_clock_func (GstElement * element)
796 GstClock *result = NULL;
797 GstElement *provider = NULL;
801 GstClock **provided_clock_p;
802 GstElement **clock_provider_p;
804 bin = GST_BIN_CAST (element);
806 GST_OBJECT_LOCK (bin);
807 if (!bin->clock_dirty)
810 GST_DEBUG_OBJECT (bin, "finding new clock");
812 it = gst_bin_sort_iterator_new (bin);
814 while (it->next (it, &val) == GST_ITERATOR_OK) {
815 GstElement *child = GST_ELEMENT_CAST (val);
818 clock = gst_element_provide_clock (child);
820 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
821 clock, GST_ELEMENT_NAME (child));
823 gst_object_unref (result);
824 gst_object_unref (provider);
829 gst_object_unref (child);
833 provided_clock_p = &bin->provided_clock;
834 clock_provider_p = &bin->clock_provider;
835 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
836 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
837 bin->clock_dirty = FALSE;
838 GST_DEBUG_OBJECT (bin,
839 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
841 /* Provider is not being returned to caller, just the result */
843 gst_object_unref (provider);
844 GST_OBJECT_UNLOCK (bin);
846 gst_iterator_free (it);
852 if ((result = bin->provided_clock))
853 gst_object_ref (result);
854 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
855 GST_OBJECT_UNLOCK (bin);
862 * functions for manipulating cached messages
867 GstMessageType types;
870 /* check if a message is of given src and type */
872 message_check (GstMessage * message, MessageFind * target)
877 eq &= GST_MESSAGE_SRC (message) == target->src;
879 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
880 GST_LOG ("looking at message %p: %d", message, eq);
886 find_message (GstBin * bin, GstObject * src, GstMessageType types)
894 result = g_list_find_custom (bin->messages, &find,
895 (GCompareFunc) message_check);
898 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
899 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
902 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
903 #ifndef GST_DISABLE_GST_DEBUG
907 for (i = 0; i < 32; i++)
908 if (types & (1 << i))
909 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
917 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
920 * A message that is cached and has the same SRC and type is replaced
921 * by the given message.
924 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
930 if ((src = GST_MESSAGE_SRC (message))) {
931 /* first find the previous message posted by this element */
932 if ((previous = find_message (bin, src, types))) {
933 GstMessage *previous_msg;
935 /* if we found a previous message, replace it */
936 previous_msg = previous->data;
937 previous->data = message;
939 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
940 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
941 GST_MESSAGE_TYPE_NAME (message));
943 gst_message_unref (previous_msg);
945 /* keep new message */
946 bin->messages = g_list_prepend (bin->messages, message);
948 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
949 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
952 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
953 GST_MESSAGE_TYPE_NAME (message));
955 gst_message_unref (message);
960 /* with LOCK. Remove all messages of given types */
962 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
970 for (walk = bin->messages; walk; walk = next) {
971 GstMessage *message = (GstMessage *) walk->data;
973 next = g_list_next (walk);
975 if (message_check (message, &find) == 0) {
976 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
977 "deleting message %p of types 0x%08x", message, types);
978 bin->messages = g_list_delete_link (bin->messages, walk);
979 gst_message_unref (message);
981 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
982 "not deleting message %p of type 0x%08x", message,
983 GST_MESSAGE_TYPE (message));
989 /* Check if the bin is EOS. We do this by scanning all sinks and
990 * checking if they posted an EOS message.
992 * call with bin LOCK */
994 is_eos (GstBin * bin, guint32 * seqnum)
1001 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1002 GstElement *element;
1004 element = GST_ELEMENT_CAST (walk->data);
1005 if (bin_element_is_sink (element, bin) == 0) {
1006 /* check if element posted EOS */
1008 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
1009 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1010 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1013 GST_DEBUG ("sink '%s' did not post EOS yet",
1014 GST_ELEMENT_NAME (element));
1020 /* FIXME: Some tests (e.g. elements/capsfilter) use
1021 * pipelines with a dangling sinkpad but no sink element.
1022 * These tests assume that no EOS message is ever
1023 * posted on the bus so let's keep that behaviour.
1024 * In valid pipelines this doesn't make a difference.
1026 return result && n_eos > 0;
1030 unlink_pads (GstPad * pad)
1034 if ((peer = gst_pad_get_peer (pad))) {
1035 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1036 gst_pad_unlink (pad, peer);
1038 gst_pad_unlink (peer, pad);
1039 gst_object_unref (peer);
1041 gst_object_unref (pad);
1044 /* vmethod that adds an element to a bin
1049 gst_bin_add_func (GstBin * bin, GstElement * element)
1053 gboolean is_sink, is_source;
1054 GstMessage *clock_message = NULL, *async_message = NULL;
1055 GstStateChangeReturn ret;
1057 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1059 /* we obviously can't add ourself to ourself */
1060 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1063 /* get the element name to make sure it is unique in this bin. */
1064 GST_OBJECT_LOCK (element);
1065 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1066 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1067 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1068 GST_OBJECT_UNLOCK (element);
1070 GST_OBJECT_LOCK (bin);
1072 /* then check to see if the element's name is already taken in the bin,
1073 * we can safely take the lock here. This check is probably bogus because
1074 * you can safely change the element name after this check and before setting
1075 * the object parent. The window is very small though... */
1076 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1077 goto duplicate_name;
1079 /* set the element's parent and add the element to the bin's list of children */
1080 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1081 GST_OBJECT_CAST (bin))))
1084 /* if we add a sink we become a sink */
1086 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1088 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1091 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1093 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1095 if (gst_element_provides_clock (element)) {
1096 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1098 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1101 bin->children = g_list_prepend (bin->children, element);
1103 bin->children_cookie++;
1104 bin->priv->structure_cookie++;
1106 /* distribute the bus */
1107 gst_element_set_bus (element, bin->child_bus);
1109 /* propagate the current base_time, start_time and clock */
1110 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1111 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1112 /* it's possible that the element did not accept the clock but
1113 * that is not important right now. When the pipeline goes to PLAYING,
1114 * a new clock will be selected */
1115 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1116 /* set the cached index on the children */
1117 if (bin->priv->index)
1118 gst_element_set_index (element, bin->priv->index);
1120 ret = GST_STATE_RETURN (bin);
1121 /* no need to update the state if we are in error */
1122 if (ret == GST_STATE_CHANGE_FAILURE)
1123 goto no_state_recalc;
1125 /* update the bin state, the new element could have been an ASYNC or
1126 * NO_PREROLL element */
1127 ret = GST_STATE_RETURN (element);
1128 GST_DEBUG_OBJECT (bin, "added %s element",
1129 gst_element_state_change_return_get_name (ret));
1132 case GST_STATE_CHANGE_ASYNC:
1134 /* create message to track this aync element when it posts an async-done
1137 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1140 case GST_STATE_CHANGE_NO_PREROLL:
1141 /* ignore all async elements we might have and commit our state */
1142 bin_handle_async_done (bin, ret, FALSE);
1144 case GST_STATE_CHANGE_FAILURE:
1151 GST_OBJECT_UNLOCK (bin);
1153 /* post the messages on the bus of the element so that the bin can handle
1156 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1159 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1161 /* unlink all linked pads */
1162 it = gst_element_iterate_pads (element);
1163 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1164 gst_iterator_free (it);
1166 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1170 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1171 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1175 /* ERROR handling here */
1178 GST_OBJECT_LOCK (bin);
1179 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1180 GST_OBJECT_UNLOCK (bin);
1185 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1186 elem_name, GST_ELEMENT_NAME (bin));
1187 GST_OBJECT_UNLOCK (bin);
1193 g_warning ("Element '%s' already has parent", elem_name);
1194 GST_OBJECT_UNLOCK (bin);
1203 * @element: (transfer full): the #GstElement to add
1205 * Adds the given element to the bin. Sets the element's parent, and thus
1206 * takes ownership of the element. An element can only be added to one bin.
1208 * If the element's pads are linked to other pads, the pads will be unlinked
1209 * before the element is added to the bin.
1212 * When you add an element to an already-running pipeline, you will have to
1213 * take care to set the state of the newly-added element to the desired
1214 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1215 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1216 * The bin or pipeline will not take care of this for you.
1221 * Returns: TRUE if the element could be added, FALSE if
1222 * the bin does not want to accept the element.
1225 gst_bin_add (GstBin * bin, GstElement * element)
1227 GstBinClass *bclass;
1230 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1231 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1233 bclass = GST_BIN_GET_CLASS (bin);
1235 if (G_UNLIKELY (bclass->add_element == NULL))
1238 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1239 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1240 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1242 result = bclass->add_element (bin, element);
1246 /* ERROR handling */
1249 g_warning ("adding elements to bin '%s' is not supported",
1250 GST_ELEMENT_NAME (bin));
1255 /* remove an element from the bin
1260 gst_bin_remove_func (GstBin * bin, GstElement * element)
1264 gboolean is_sink, is_source, othersink, othersource, found;
1265 GstMessage *clock_message = NULL;
1266 GstClock **provided_clock_p;
1267 GstElement **clock_provider_p;
1269 gboolean other_async, this_async, have_no_preroll;
1270 GstStateChangeReturn ret;
1272 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1274 GST_OBJECT_LOCK (element);
1275 /* Check if the element is already being removed and immediately
1277 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1278 goto already_removing;
1280 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1281 /* grab element name so we can print it */
1282 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1283 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1284 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1285 GST_OBJECT_UNLOCK (element);
1287 /* unlink all linked pads */
1288 it = gst_element_iterate_pads (element);
1289 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1290 gst_iterator_free (it);
1292 GST_OBJECT_LOCK (bin);
1295 othersource = FALSE;
1296 have_no_preroll = FALSE;
1297 /* iterate the elements, we collect which ones are async and no_preroll. We
1298 * also remove the element when we find it. */
1299 for (walk = bin->children; walk; walk = next) {
1300 GstElement *child = GST_ELEMENT_CAST (walk->data);
1302 next = g_list_next (walk);
1304 if (child == element) {
1306 /* remove the element */
1307 bin->children = g_list_delete_link (bin->children, walk);
1309 gboolean child_sink, child_source;
1311 GST_OBJECT_LOCK (child);
1312 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1313 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1314 /* when we remove a sink, check if there are other sinks. */
1315 if (is_sink && !othersink && child_sink)
1317 if (is_source && !othersource && child_source)
1319 /* check if we have NO_PREROLL children */
1320 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1321 have_no_preroll = TRUE;
1322 GST_OBJECT_UNLOCK (child);
1326 /* the element must have been in the bin's list of children */
1327 if (G_UNLIKELY (!found))
1330 /* we now removed the element from the list of elements, increment the cookie
1331 * so that others can detect a change in the children list. */
1333 bin->children_cookie++;
1334 bin->priv->structure_cookie++;
1336 if (is_sink && !othersink) {
1337 /* we're not a sink anymore */
1338 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1339 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1341 if (is_source && !othersource) {
1342 /* we're not a source anymore */
1343 GST_DEBUG_OBJECT (bin, "we removed the last source");
1344 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1348 /* if the clock provider for this element is removed, we lost
1349 * the clock as well, we need to inform the parent of this
1350 * so that it can select a new clock */
1351 if (bin->clock_provider == element) {
1352 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1353 bin->clock_dirty = TRUE;
1355 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1356 provided_clock_p = &bin->provided_clock;
1357 clock_provider_p = &bin->clock_provider;
1358 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1359 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1362 /* remove messages for the element, if there was a pending ASYNC_START
1363 * message we must see if removing the element caused the bin to lose its
1366 other_async = FALSE;
1367 for (walk = bin->messages; walk; walk = next) {
1368 GstMessage *message = (GstMessage *) walk->data;
1369 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1372 next = g_list_next (walk);
1375 switch (GST_MESSAGE_TYPE (message)) {
1376 case GST_MESSAGE_ASYNC_START:
1382 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1384 case GST_MESSAGE_STRUCTURE_CHANGE:
1388 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1390 /* it's unlikely that this message is still in the list of messages
1391 * because this would mean that a link/unlink is busy in another thread
1392 * while we remove the element. We still have to remove the message
1393 * because we might not receive the done message anymore when the element
1394 * is removed from the bin. */
1395 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1396 if (owner == element)
1407 /* delete all message types */
1408 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1409 message, elem_name);
1410 bin->messages = g_list_delete_link (bin->messages, walk);
1411 gst_message_unref (message);
1415 /* get last return */
1416 ret = GST_STATE_RETURN (bin);
1418 /* no need to update the state if we are in error */
1419 if (ret == GST_STATE_CHANGE_FAILURE)
1420 goto no_state_recalc;
1422 if (!other_async && this_async) {
1423 /* all other elements were not async and we removed the async one,
1424 * handle the async-done case because we are not async anymore now. */
1425 GST_DEBUG_OBJECT (bin,
1426 "we removed the last async element, have no_preroll %d",
1429 /* the current state return of the bin depends on if there are no_preroll
1430 * elements in the pipeline or not */
1431 if (have_no_preroll)
1432 ret = GST_STATE_CHANGE_NO_PREROLL;
1434 ret = GST_STATE_CHANGE_SUCCESS;
1436 bin_handle_async_done (bin, ret, FALSE);
1438 GST_DEBUG_OBJECT (bin,
1439 "recalc state preroll: %d, other async: %d, this async %d",
1440 have_no_preroll, other_async, this_async);
1442 if (have_no_preroll) {
1443 ret = GST_STATE_CHANGE_NO_PREROLL;
1444 } else if (other_async) {
1445 /* there are other async elements and we were not doing an async state
1446 * change, change our pending state and go async */
1447 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1448 GST_STATE_NEXT (bin) = GST_STATE (bin);
1449 GST_STATE_PENDING (bin) = GST_STATE (bin);
1451 ret = GST_STATE_CHANGE_ASYNC;
1453 GST_STATE_RETURN (bin) = ret;
1456 GST_OBJECT_UNLOCK (bin);
1459 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1461 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1465 gst_element_set_bus (element, NULL);
1467 /* Clear the clock we provided to the element */
1468 gst_element_set_clock (element, NULL);
1470 /* we ref here because after the _unparent() the element can be disposed
1471 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1472 gst_object_ref (element);
1473 gst_object_unparent (GST_OBJECT_CAST (element));
1475 GST_OBJECT_LOCK (element);
1476 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1477 GST_OBJECT_UNLOCK (element);
1479 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1480 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1482 /* element is really out of our control now */
1483 gst_object_unref (element);
1487 /* ERROR handling */
1490 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1491 GST_ELEMENT_NAME (bin));
1492 GST_OBJECT_UNLOCK (bin);
1498 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1499 GST_OBJECT_UNLOCK (element);
1507 * @element: (transfer none): the #GstElement to remove
1509 * Removes the element from the bin, unparenting it as well.
1510 * Unparenting the element means that the element will be dereferenced,
1511 * so if the bin holds the only reference to the element, the element
1512 * will be freed in the process of removing it from the bin. If you
1513 * want the element to still exist after removing, you need to call
1514 * gst_object_ref() before removing it from the bin.
1516 * If the element's pads are linked to other pads, the pads will be unlinked
1517 * before the element is removed from the bin.
1521 * Returns: TRUE if the element could be removed, FALSE if
1522 * the bin does not want to remove the element.
1525 gst_bin_remove (GstBin * bin, GstElement * element)
1527 GstBinClass *bclass;
1530 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1531 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1533 bclass = GST_BIN_GET_CLASS (bin);
1535 if (G_UNLIKELY (bclass->remove_element == NULL))
1538 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1539 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1541 result = bclass->remove_element (bin, element);
1545 /* ERROR handling */
1548 g_warning ("removing elements from bin '%s' is not supported",
1549 GST_ELEMENT_NAME (bin));
1554 static GstIteratorItem
1555 iterate_child (GstIterator * it, GstElement * child)
1557 gst_object_ref (child);
1558 return GST_ITERATOR_ITEM_PASS;
1562 * gst_bin_iterate_elements:
1565 * Gets an iterator for the elements in this bin.
1567 * Each element yielded by the iterator will have its refcount increased, so
1570 * MT safe. Caller owns returned value.
1572 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1575 gst_bin_iterate_elements (GstBin * bin)
1577 GstIterator *result;
1579 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1581 GST_OBJECT_LOCK (bin);
1582 /* add ref because the iterator refs the bin. When the iterator
1583 * is freed it will unref the bin again using the provided dispose
1585 gst_object_ref (bin);
1586 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1587 GST_OBJECT_GET_LOCK (bin),
1588 &bin->children_cookie,
1591 (GstIteratorItemFunction) iterate_child,
1592 (GstIteratorDisposeFunction) gst_object_unref);
1593 GST_OBJECT_UNLOCK (bin);
1598 static GstIteratorItem
1599 iterate_child_recurse (GstIterator * it, GstElement * child)
1601 gst_object_ref (child);
1602 if (GST_IS_BIN (child)) {
1603 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1605 gst_iterator_push (it, other);
1607 return GST_ITERATOR_ITEM_PASS;
1611 * gst_bin_iterate_recurse:
1614 * Gets an iterator for the elements in this bin.
1615 * This iterator recurses into GstBin children.
1617 * Each element yielded by the iterator will have its refcount increased, so
1620 * MT safe. Caller owns returned value.
1622 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1625 gst_bin_iterate_recurse (GstBin * bin)
1627 GstIterator *result;
1629 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1631 GST_OBJECT_LOCK (bin);
1632 /* add ref because the iterator refs the bin. When the iterator
1633 * is freed it will unref the bin again using the provided dispose
1635 gst_object_ref (bin);
1636 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1637 GST_OBJECT_GET_LOCK (bin),
1638 &bin->children_cookie,
1641 (GstIteratorItemFunction) iterate_child_recurse,
1642 (GstIteratorDisposeFunction) gst_object_unref);
1643 GST_OBJECT_UNLOCK (bin);
1648 /* returns 0 when TRUE because this is a GCompareFunc */
1651 bin_element_is_sink (GstElement * child, GstBin * bin)
1655 /* we lock the child here for the remainder of the function to
1656 * get its name and flag safely. */
1657 GST_OBJECT_LOCK (child);
1658 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1660 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1661 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1663 GST_OBJECT_UNLOCK (child);
1664 return is_sink ? 0 : 1;
1668 sink_iterator_filter (GstElement * child, GstBin * bin)
1670 if (bin_element_is_sink (child, bin) == 0) {
1671 /* returns 0 because this is a GCompareFunc */
1674 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1676 gst_object_unref (child);
1682 * gst_bin_iterate_sinks:
1685 * Gets an iterator for all elements in the bin that have the
1686 * #GST_ELEMENT_IS_SINK flag set.
1688 * Each element yielded by the iterator will have its refcount increased, so
1691 * MT safe. Caller owns returned value.
1693 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1696 gst_bin_iterate_sinks (GstBin * bin)
1698 GstIterator *children;
1699 GstIterator *result;
1701 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1703 children = gst_bin_iterate_elements (bin);
1704 result = gst_iterator_filter (children,
1705 (GCompareFunc) sink_iterator_filter, bin);
1710 /* returns 0 when TRUE because this is a GCompareFunc */
1713 bin_element_is_src (GstElement * child, GstBin * bin)
1717 /* we lock the child here for the remainder of the function to
1718 * get its name and other info safely. */
1719 GST_OBJECT_LOCK (child);
1720 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1722 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1723 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1725 GST_OBJECT_UNLOCK (child);
1726 return is_src ? 0 : 1;
1730 src_iterator_filter (GstElement * child, GstBin * bin)
1732 if (bin_element_is_src (child, bin) == 0) {
1733 /* returns 0 because this is a GCompareFunc */
1736 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1738 gst_object_unref (child);
1744 * gst_bin_iterate_sources:
1747 * Gets an iterator for all elements in the bin that have the
1748 * #GST_ELEMENT_IS_SOURCE flag set.
1750 * Each element yielded by the iterator will have its refcount increased, so
1753 * MT safe. Caller owns returned value.
1755 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1758 gst_bin_iterate_sources (GstBin * bin)
1760 GstIterator *children;
1761 GstIterator *result;
1763 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1765 children = gst_bin_iterate_elements (bin);
1766 result = gst_iterator_filter (children,
1767 (GCompareFunc) src_iterator_filter, bin);
1775 static GstStateChangeReturn
1776 gst_bin_get_state_func (GstElement * element, GstState * state,
1777 GstState * pending, GstClockTime timeout)
1779 GstStateChangeReturn ret;
1781 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1783 ret = parent_class->get_state (element, state, pending, timeout);
1788 /***********************************************
1789 * Topologically sorted iterator
1790 * see http://en.wikipedia.org/wiki/Topological_sorting
1792 * For each element in the graph, an entry is kept in a HashTable
1793 * with its number of srcpad connections (degree).
1794 * We then change state of all elements without dependencies
1795 * (degree 0) and decrement the degree of all elements connected
1796 * on the sinkpads. When an element reaches degree 0, its state is
1798 * When all elements are handled the algorithm stops.
1800 typedef struct _GstBinSortIterator
1803 GQueue queue; /* elements queued for state change */
1804 GstBin *bin; /* bin we iterate */
1805 gint mode; /* adding or removing dependency */
1806 GstElement *best; /* next element with least dependencies */
1807 gint best_deg; /* best degree */
1808 GHashTable *hash; /* hashtable with element dependencies */
1809 gboolean dirty; /* we detected structure change */
1810 } GstBinSortIterator;
1812 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1813 #define HASH_SET_DEGREE(bit, elem, deg) \
1814 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1815 #define HASH_GET_DEGREE(bit, elem) \
1816 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1818 /* add element to queue of next elements in the iterator.
1819 * We push at the tail to give higher priority elements a
1822 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1824 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1825 GST_ELEMENT_NAME (element));
1826 gst_object_ref (element);
1827 g_queue_push_tail (&bit->queue, element);
1828 HASH_SET_DEGREE (bit, element, -1);
1832 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1836 if ((find = g_queue_find (&bit->queue, element))) {
1837 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1838 GST_ELEMENT_NAME (element));
1840 g_queue_delete_link (&bit->queue, find);
1841 gst_object_unref (element);
1843 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1844 GST_ELEMENT_NAME (element));
1848 /* clear the queue, unref all objects as we took a ref when
1849 * we added them to the queue */
1851 clear_queue (GQueue * queue)
1855 while ((p = g_queue_pop_head (queue)))
1856 gst_object_unref (p);
1859 /* set all degrees to 0. Elements marked as a sink are
1860 * added to the queue immediately. Since we only look at the SINK flag of the
1861 * element, it is possible that we add non-sinks to the queue. These will be
1862 * removed from the queue again when we can prove that it provides data for some
1865 reset_degree (GstElement * element, GstBinSortIterator * bit)
1869 /* sinks are added right away */
1870 GST_OBJECT_LOCK (element);
1871 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1872 GST_OBJECT_UNLOCK (element);
1875 add_to_queue (bit, element);
1877 /* others are marked with 0 and handled when sinks are done */
1878 HASH_SET_DEGREE (bit, element, 0);
1882 /* adjust the degree of all elements connected to the given
1883 * element. If a degree of an element drops to 0, it is
1884 * added to the queue of elements to schedule next.
1886 * We have to make sure not to cross the bin boundary this element
1890 update_degree (GstElement * element, GstBinSortIterator * bit)
1892 gboolean linked = FALSE;
1894 GST_OBJECT_LOCK (element);
1895 /* don't touch degree if element has no sinkpads */
1896 if (element->numsinkpads != 0) {
1897 /* loop over all sinkpads, decrement degree for all connected
1898 * elements in this bin */
1901 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1904 pad = GST_PAD_CAST (pads->data);
1906 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1907 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1908 GST_MESSAGE_STRUCTURE_CHANGE))) {
1909 /* mark the iterator as dirty because we won't be updating the degree
1910 * of the peer parent now. This would result in the 'loop detected'
1911 * later on because the peer parent element could become the best next
1912 * element with a degree > 0. We will simply continue our state
1913 * changes and we'll eventually resync when the unlink completed and
1914 * the iterator cookie is updated. */
1919 if ((peer = gst_pad_get_peer (pad))) {
1920 GstElement *peer_element;
1922 if ((peer_element = gst_pad_get_parent_element (peer))) {
1923 GST_OBJECT_LOCK (peer_element);
1924 /* check that we don't go outside of this bin */
1925 if (GST_OBJECT_CAST (peer_element)->parent ==
1926 GST_OBJECT_CAST (bit->bin)) {
1927 gint old_deg, new_deg;
1929 old_deg = HASH_GET_DEGREE (bit, peer_element);
1931 /* check to see if we added an element as sink that was not really a
1932 * sink because it was connected to some other element. */
1933 if (old_deg == -1) {
1934 remove_from_queue (bit, peer_element);
1937 new_deg = old_deg + bit->mode;
1939 GST_DEBUG_OBJECT (bit->bin,
1940 "change element %s, degree %d->%d, linked to %s",
1941 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1942 GST_ELEMENT_NAME (element));
1944 /* update degree, it is possible that an element was in 0 and
1945 * reaches -1 here. This would mean that the element had no sinkpads
1946 * but became linked while the state change was happening. We will
1947 * resync on this with the structure change message. */
1949 /* degree hit 0, add to queue */
1950 add_to_queue (bit, peer_element);
1952 HASH_SET_DEGREE (bit, peer_element, new_deg);
1956 GST_OBJECT_UNLOCK (peer_element);
1957 gst_object_unref (peer_element);
1959 gst_object_unref (peer);
1964 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1965 GST_ELEMENT_NAME (element));
1967 GST_OBJECT_UNLOCK (element);
1970 /* find the next best element not handled yet. This is the one
1971 * with the lowest non-negative degree */
1973 find_element (GstElement * element, GstBinSortIterator * bit)
1977 /* element is already handled */
1978 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1981 /* first element or element with smaller degree */
1982 if (bit->best == NULL || bit->best_deg > degree) {
1983 bit->best = element;
1984 bit->best_deg = degree;
1988 /* get next element in iterator. the returned element has the
1989 * refcount increased */
1990 static GstIteratorResult
1991 gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
1993 GstBin *bin = bit->bin;
1995 /* empty queue, we have to find a next best element */
1996 if (g_queue_is_empty (&bit->queue)) {
2000 bit->best_deg = G_MAXINT;
2001 g_list_foreach (bin->children, (GFunc) find_element, bit);
2002 if ((best = bit->best)) {
2003 /* when we detected an unlink, don't warn because our degrees might be
2004 * screwed up. We will resync later */
2005 if (bit->best_deg != 0 && !bit->dirty) {
2006 /* we don't fail on this one yet */
2007 GST_WARNING_OBJECT (bin, "loop dected in graph");
2008 g_warning ("loop detected in the graph of bin '%s'!!",
2009 GST_ELEMENT_NAME (bin));
2011 /* best unhandled element, schedule as next element */
2012 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2013 GST_ELEMENT_NAME (best));
2014 gst_object_ref (best);
2015 HASH_SET_DEGREE (bit, best, -1);
2018 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2019 /* no more unhandled elements, we are done */
2020 return GST_ITERATOR_DONE;
2023 /* everything added to the queue got reffed */
2024 *result = g_queue_pop_head (&bit->queue);
2027 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
2028 /* update degrees of linked elements */
2029 update_degree (GST_ELEMENT_CAST (*result), bit);
2031 return GST_ITERATOR_OK;
2034 /* clear queues, recalculate the degrees and restart. */
2036 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2038 GstBin *bin = bit->bin;
2040 GST_DEBUG_OBJECT (bin, "resync");
2042 clear_queue (&bit->queue);
2044 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2045 /* calc degrees, incrementing */
2047 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2048 /* for the rest of the function we decrement the degrees */
2052 /* clear queues, unref bin and free iterator. */
2054 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2056 GstBin *bin = bit->bin;
2058 GST_DEBUG_OBJECT (bin, "free");
2059 clear_queue (&bit->queue);
2060 g_hash_table_destroy (bit->hash);
2061 gst_object_unref (bin);
2065 /* should be called with the bin LOCK held */
2066 static GstIterator *
2067 gst_bin_sort_iterator_new (GstBin * bin)
2069 GstBinSortIterator *result;
2071 /* we don't need an ItemFunction because we ref the items in the _next
2073 result = (GstBinSortIterator *)
2074 gst_iterator_new (sizeof (GstBinSortIterator),
2076 GST_OBJECT_GET_LOCK (bin),
2077 &bin->priv->structure_cookie,
2078 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2079 (GstIteratorItemFunction) NULL,
2080 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2081 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2082 g_queue_init (&result->queue);
2083 result->hash = g_hash_table_new (NULL, NULL);
2084 gst_object_ref (bin);
2086 gst_bin_sort_iterator_resync (result);
2088 return (GstIterator *) result;
2092 * gst_bin_iterate_sorted:
2095 * Gets an iterator for the elements in this bin in topologically
2096 * sorted order. This means that the elements are returned from
2097 * the most downstream elements (sinks) to the sources.
2099 * This function is used internally to perform the state changes
2100 * of the bin elements and for clock selection.
2102 * Each element yielded by the iterator will have its refcount increased, so
2105 * MT safe. Caller owns returned value.
2107 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2110 gst_bin_iterate_sorted (GstBin * bin)
2112 GstIterator *result;
2114 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2116 GST_OBJECT_LOCK (bin);
2117 result = gst_bin_sort_iterator_new (bin);
2118 GST_OBJECT_UNLOCK (bin);
2123 static GstStateChangeReturn
2124 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2125 GstClockTime base_time, GstClockTime start_time, GstState current,
2128 GstStateChangeReturn ret;
2129 GstState pending, child_current, child_pending;
2133 GST_STATE_LOCK (element);
2135 GST_OBJECT_LOCK (element);
2136 /* set base_time and start time on child */
2137 GST_ELEMENT_START_TIME (element) = start_time;
2138 element->base_time = base_time;
2139 /* peel off the locked flag */
2140 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2141 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2142 ret = GST_STATE_RETURN (element);
2143 child_current = GST_STATE (element);
2144 child_pending = GST_STATE_PENDING (element);
2145 GST_OBJECT_UNLOCK (element);
2147 /* skip locked elements */
2148 if (G_UNLIKELY (locked))
2151 /* if the element was no preroll, just start changing the state regardless
2152 * if it had async elements (in the case of a bin) because they won't preroll
2154 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2155 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2159 GST_OBJECT_LOCK (bin);
2160 pending = GST_STATE_PENDING (bin);
2162 /* Try not to change the state of elements that are already in the state we're
2164 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2165 (child_pending == GST_STATE_VOID_PENDING &&
2166 ((pending > child_current && next > child_current) ||
2167 (pending < child_current && next < child_current)))))
2170 /* the element was busy with an upwards async state change, we must wait for
2171 * an ASYNC_DONE message before we attemp to change the state. */
2173 find_message (bin, GST_OBJECT_CAST (element),
2174 GST_MESSAGE_ASYNC_START))) {
2175 #ifndef GST_DISABLE_GST_DEBUG
2176 GstMessage *message = GST_MESSAGE_CAST (found->data);
2178 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2179 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2181 /* only wait for upward state changes */
2182 if (next > current) {
2183 /* We found an async element check if we can force its state to change or
2184 * if we have to wait for it to preroll. */
2185 if (G_UNLIKELY (!enable_latency)) {
2186 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2187 "\tto preroll in order to perform correct latency calculations.\n"
2188 "\tPlease verify that the application continues to work correctly by\n"
2189 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2190 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2197 GST_OBJECT_UNLOCK (bin);
2200 GST_DEBUG_OBJECT (bin,
2201 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2202 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2203 GST_TIME_ARGS (base_time));
2206 ret = gst_element_set_state (element, next);
2208 GST_STATE_UNLOCK (element);
2214 GST_DEBUG_OBJECT (element,
2215 "element is locked, return previous return %s",
2216 gst_element_state_change_return_get_name (ret));
2217 GST_STATE_UNLOCK (element);
2222 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2223 GST_OBJECT_UNLOCK (bin);
2224 GST_STATE_UNLOCK (element);
2225 return GST_STATE_CHANGE_ASYNC;
2229 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2230 "skipping transition from %s to %s, since bin pending"
2231 " is %s : last change state return follows",
2232 gst_element_state_get_name (child_current),
2233 gst_element_state_get_name (next),
2234 gst_element_state_get_name (pending));
2235 GST_OBJECT_UNLOCK (bin);
2236 GST_STATE_UNLOCK (element);
2241 /* gst_iterator_fold functions for pads_activate
2242 * Stop the iterator if activating one pad failed. */
2244 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2246 gboolean cont = TRUE;
2248 if (!(cont = gst_pad_set_active (pad, *active)))
2249 g_value_set_boolean (ret, FALSE);
2251 gst_pad_set_caps (pad, NULL);
2253 /* unref the object that was reffed for us by _fold */
2254 gst_object_unref (pad);
2258 /* returns false on error or early cutout of the fold, true if all
2259 * pads in @iter were (de)activated successfully. */
2261 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2263 GstIteratorResult ires;
2266 /* no need to unset this later, it's just a boolean */
2267 g_value_init (&ret, G_TYPE_BOOLEAN);
2268 g_value_set_boolean (&ret, TRUE);
2271 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2274 case GST_ITERATOR_RESYNC:
2275 /* need to reset the result again */
2276 g_value_set_boolean (&ret, TRUE);
2277 gst_iterator_resync (iter);
2279 case GST_ITERATOR_DONE:
2280 /* all pads iterated, return collected value */
2283 /* iterator returned _ERROR or premature end with _OK,
2284 * mark an error and exit */
2285 g_value_set_boolean (&ret, FALSE);
2290 /* return collected value */
2291 return g_value_get_boolean (&ret);
2294 /* is called with STATE_LOCK
2297 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2302 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2304 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2305 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2306 gst_iterator_free (iter);
2307 if (G_UNLIKELY (!fold_ok))
2310 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2317 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2323 * gst_bin_recalculate_latency:
2326 * Query @bin for the current latency using and reconfigures this latency to all the
2327 * elements with a LATENCY event.
2329 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2330 * is posted on the bus.
2332 * This function simply emits the 'do-latency' signal so any custom latency
2333 * calculations will be performed.
2335 * Returns: %TRUE if the latency could be queried and reconfigured.
2340 gst_bin_recalculate_latency (GstBin * bin)
2344 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2345 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2351 gst_bin_do_latency_func (GstBin * bin)
2354 GstElement *element;
2355 GstClockTime min_latency, max_latency;
2358 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2360 element = GST_ELEMENT_CAST (bin);
2362 GST_DEBUG_OBJECT (element, "querying latency");
2364 query = gst_query_new_latency ();
2365 if ((res = gst_element_query (element, query))) {
2368 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2370 GST_DEBUG_OBJECT (element,
2371 "got min latency %" GST_TIME_FORMAT ", max latency %"
2372 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2373 GST_TIME_ARGS (max_latency), live);
2375 if (max_latency < min_latency) {
2376 /* this is an impossible situation, some parts of the pipeline might not
2377 * work correctly. We post a warning for now. */
2378 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2379 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2380 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2381 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2384 /* configure latency on elements */
2385 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2387 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2388 GST_TIME_ARGS (min_latency));
2390 GST_WARNING_OBJECT (element,
2391 "did not really configure latency of %" GST_TIME_FORMAT,
2392 GST_TIME_ARGS (min_latency));
2395 /* this is not a real problem, we just don't configure any latency. */
2396 GST_WARNING_OBJECT (element, "failed to query latency");
2398 gst_query_unref (query);
2404 gst_bin_state_changed (GstElement * element, GstState oldstate,
2405 GstState newstate, GstState pending)
2407 GstElementClass *pklass = (GstElementClass *) parent_class;
2409 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2410 bin_do_eos (GST_BIN_CAST (element));
2412 if (pklass->state_changed)
2413 pklass->state_changed (element, oldstate, newstate, pending);
2416 static GstStateChangeReturn
2417 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2420 GstStateChangeReturn ret;
2421 GstState current, next;
2422 gboolean have_async;
2423 gboolean have_no_preroll;
2424 GstClockTime base_time, start_time;
2428 /* we don't need to take the STATE_LOCK, it is already taken */
2429 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2430 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2432 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2433 "changing state of children from %s to %s",
2434 gst_element_state_get_name (current), gst_element_state_get_name (next));
2436 bin = GST_BIN_CAST (element);
2439 case GST_STATE_PLAYING:
2443 GST_OBJECT_LOCK (bin);
2444 toplevel = BIN_IS_TOPLEVEL (bin);
2445 GST_OBJECT_UNLOCK (bin);
2448 gst_bin_recalculate_latency (bin);
2451 case GST_STATE_PAUSED:
2452 /* Clear EOS list on next PAUSED */
2453 GST_OBJECT_LOCK (bin);
2454 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2455 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2456 bin->priv->posted_eos = FALSE;
2457 GST_OBJECT_UNLOCK (bin);
2458 if (current == GST_STATE_READY)
2459 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2460 goto activate_failure;
2462 case GST_STATE_READY:
2463 /* Clear message list on next READY */
2464 GST_OBJECT_LOCK (bin);
2465 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2466 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2467 GST_OBJECT_UNLOCK (bin);
2468 if (current == GST_STATE_PAUSED)
2469 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2470 goto activate_failure;
2472 case GST_STATE_NULL:
2473 if (current == GST_STATE_READY)
2474 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2475 goto activate_failure;
2481 /* this flag is used to make the async state changes return immediately. We
2482 * don't want them to interfere with this state change */
2483 GST_OBJECT_LOCK (bin);
2484 bin->polling = TRUE;
2485 GST_OBJECT_UNLOCK (bin);
2487 /* iterate in state change order */
2488 it = gst_bin_iterate_sorted (bin);
2490 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2491 * Note how we don't reset this value when a resync happens, the reason being
2492 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2493 * even after a resync when the async element is gone */
2497 /* take base_time */
2498 base_time = gst_element_get_base_time (element);
2499 start_time = gst_element_get_start_time (element);
2501 have_no_preroll = FALSE;
2507 switch (gst_iterator_next (it, &data)) {
2508 case GST_ITERATOR_OK:
2512 child = GST_ELEMENT_CAST (data);
2514 /* set state and base_time now */
2515 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2519 case GST_STATE_CHANGE_SUCCESS:
2520 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2521 "child '%s' changed state to %d(%s) successfully",
2522 GST_ELEMENT_NAME (child), next,
2523 gst_element_state_get_name (next));
2525 case GST_STATE_CHANGE_ASYNC:
2527 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2528 "child '%s' is changing state asynchronously to %s",
2529 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2533 case GST_STATE_CHANGE_FAILURE:{
2536 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2537 "child '%s' failed to go to state %d(%s)",
2538 GST_ELEMENT_NAME (child),
2539 next, gst_element_state_get_name (next));
2541 /* Only fail if the child is still inside
2542 * this bin. It might've been removed already
2543 * because of the error by the bin subclass
2544 * to ignore the error. */
2545 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2546 if (parent == GST_OBJECT_CAST (element)) {
2547 /* element is still in bin, really error now */
2548 gst_object_unref (child);
2549 gst_object_unref (parent);
2552 /* child removed from bin, let the resync code redo the state
2554 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2555 "child '%s' was removed from the bin",
2556 GST_ELEMENT_NAME (child));
2559 gst_object_unref (parent);
2563 case GST_STATE_CHANGE_NO_PREROLL:
2564 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2565 "child '%s' changed state to %d(%s) successfully without preroll",
2566 GST_ELEMENT_NAME (child), next,
2567 gst_element_state_get_name (next));
2568 have_no_preroll = TRUE;
2571 g_assert_not_reached ();
2574 gst_object_unref (child);
2577 case GST_ITERATOR_RESYNC:
2578 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2579 gst_iterator_resync (it);
2582 case GST_ITERATOR_DONE:
2583 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2589 ret = parent_class->change_state (element, transition);
2590 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2593 if (have_no_preroll) {
2594 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2595 "we have NO_PREROLL elements %s -> NO_PREROLL",
2596 gst_element_state_change_return_get_name (ret));
2597 ret = GST_STATE_CHANGE_NO_PREROLL;
2598 } else if (have_async) {
2599 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2600 "we have ASYNC elements %s -> ASYNC",
2601 gst_element_state_change_return_get_name (ret));
2602 ret = GST_STATE_CHANGE_ASYNC;
2606 gst_iterator_free (it);
2608 GST_OBJECT_LOCK (bin);
2609 bin->polling = FALSE;
2610 /* it's possible that we did not get ASYNC from the children while the bin is
2611 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2612 * itself as the source. In that case we still want to check if the state
2613 * change completed. */
2614 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2615 /* no element returned ASYNC and there are no pending async_done messages,
2616 * we can just complete. */
2617 GST_DEBUG_OBJECT (bin, "no async elements");
2620 /* when we get here an ASYNC element was found */
2621 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2622 /* we ignore ASYNC state changes when we go to READY or NULL */
2623 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2624 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2628 GST_DEBUG_OBJECT (bin, "check async elements");
2629 /* check if all elements managed to commit their state already */
2630 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2631 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2632 * all the elements commited their state while we were doing the state
2633 * change. We will still return ASYNC for consistency but we commit the
2634 * state already so that a _get_state() will return immediately. */
2635 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2637 GST_DEBUG_OBJECT (bin, "async elements commited");
2638 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2642 bin->priv->pending_async_done = FALSE;
2643 GST_OBJECT_UNLOCK (bin);
2645 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2646 "done changing bin's state from %s to %s, now in %s, ret %s",
2647 gst_element_state_get_name (current),
2648 gst_element_state_get_name (next),
2649 gst_element_state_get_name (GST_STATE (element)),
2650 gst_element_state_change_return_get_name (ret));
2657 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2658 "failure (de)activating src pads");
2659 return GST_STATE_CHANGE_FAILURE;
2664 * This function is a utility event handler for seek events.
2665 * It will send the event to all sinks or sources depending on the
2668 * Applications are free to override this behaviour and
2669 * implement their own seek handler, but this will work for
2670 * pretty much all cases in practice.
2673 gst_bin_send_event (GstElement * element, GstEvent * event)
2675 GstBin *bin = GST_BIN_CAST (element);
2677 gboolean res = TRUE;
2678 gboolean done = FALSE;
2680 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2681 iter = gst_bin_iterate_sources (bin);
2682 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2683 GST_EVENT_TYPE_NAME (event));
2685 iter = gst_bin_iterate_sinks (bin);
2686 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2687 GST_EVENT_TYPE_NAME (event));
2693 switch (gst_iterator_next (iter, &data)) {
2694 case GST_ITERATOR_OK:
2698 gst_event_ref (event);
2699 child = GST_ELEMENT_CAST (data);
2700 res &= gst_element_send_event (child, event);
2701 GST_LOG_OBJECT (child, "After handling %s event: %d",
2702 GST_EVENT_TYPE_NAME (event), res);
2703 gst_object_unref (child);
2706 case GST_ITERATOR_RESYNC:
2707 gst_iterator_resync (iter);
2710 case GST_ITERATOR_DONE:
2713 case GST_ITERATOR_ERROR:
2714 g_assert_not_reached ();
2718 gst_iterator_free (iter);
2719 gst_event_unref (event);
2724 /* this is the function called by the threadpool. When async elements commit
2725 * their state, this function will attempt to bring the bin to the next state.
2728 gst_bin_continue_func (BinContinueData * data)
2731 GstState current, next, pending;
2732 GstStateChange transition;
2735 pending = data->pending;
2737 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2738 GST_STATE_LOCK (bin);
2740 GST_DEBUG_OBJECT (bin, "doing state continue");
2741 GST_OBJECT_LOCK (bin);
2743 /* if a new state change happened after this thread was scheduled, we return
2745 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2748 current = GST_STATE (bin);
2749 next = GST_STATE_GET_NEXT (current, pending);
2750 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2752 GST_STATE_NEXT (bin) = next;
2753 GST_STATE_PENDING (bin) = pending;
2755 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2756 GST_OBJECT_UNLOCK (bin);
2758 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2759 "continue state change %s to %s, final %s",
2760 gst_element_state_get_name (current),
2761 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2763 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2765 GST_STATE_UNLOCK (bin);
2766 GST_DEBUG_OBJECT (bin, "state continue done");
2768 gst_object_unref (bin);
2769 g_slice_free (BinContinueData, data);
2774 GST_OBJECT_UNLOCK (bin);
2775 GST_STATE_UNLOCK (bin);
2776 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2777 gst_object_unref (bin);
2778 g_slice_free (BinContinueData, data);
2783 static GstBusSyncReply
2784 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2786 GstBinClass *bclass;
2788 bclass = GST_BIN_GET_CLASS (bin);
2789 if (bclass->handle_message)
2790 bclass->handle_message (bin, message);
2792 gst_message_unref (message);
2794 return GST_BUS_DROP;
2798 bin_push_state_continue (BinContinueData * data)
2805 klass = GST_BIN_GET_CLASS (bin);
2807 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2808 g_thread_pool_push (klass->pool, data, NULL);
2811 /* an element started an async state change, if we were not busy with a state
2812 * change, we perform a lost state.
2813 * This function is called with the OBJECT lock.
2816 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2818 GstState old_state, new_state;
2820 GstMessage *amessage = NULL;
2822 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2825 /* get our toplevel state */
2826 toplevel = BIN_IS_TOPLEVEL (bin);
2828 /* prepare an ASYNC_START message, we always post the start message even if we
2829 * are busy with a state change or when we are NO_PREROLL. */
2831 /* non toplevel bin, prepare async-start for the parent */
2833 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2835 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2838 /* async starts are ignored when we are NO_PREROLL */
2839 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2840 goto was_no_preroll;
2842 old_state = GST_STATE (bin);
2844 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2845 * PLAYING after optionally redistributing the base_time. */
2846 if (old_state > GST_STATE_PAUSED)
2847 new_state = GST_STATE_PAUSED;
2849 new_state = old_state;
2851 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2852 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2853 gst_element_state_get_name (new_state));
2855 GST_STATE (bin) = new_state;
2856 GST_STATE_NEXT (bin) = new_state;
2857 GST_STATE_PENDING (bin) = new_state;
2858 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2859 GST_OBJECT_UNLOCK (bin);
2862 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2867 /* post our ASYNC_START. */
2868 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2869 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2871 GST_OBJECT_LOCK (bin);
2877 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2882 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2883 GST_OBJECT_UNLOCK (bin);
2888 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2889 GST_OBJECT_UNLOCK (bin);
2894 /* this function is called when there are no more async elements in the bin. We
2895 * post a state changed message and an ASYNC_DONE message.
2896 * This function is called with the OBJECT lock.
2899 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2900 gboolean flag_pending)
2902 GstState current, pending, target;
2903 GstStateChangeReturn old_ret;
2904 GstState old_state, old_next;
2905 gboolean toplevel, state_changed = FALSE;
2906 GstMessage *amessage = NULL;
2907 BinContinueData *cont = NULL;
2909 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2912 pending = GST_STATE_PENDING (bin);
2917 /* check if there is something to commit */
2918 if (pending == GST_STATE_VOID_PENDING)
2919 goto nothing_pending;
2921 old_ret = GST_STATE_RETURN (bin);
2922 GST_STATE_RETURN (bin) = ret;
2924 /* move to the next target state */
2925 target = GST_STATE_TARGET (bin);
2926 pending = GST_STATE_PENDING (bin) = target;
2928 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2930 old_state = GST_STATE (bin);
2931 /* this is the state we should go to next */
2932 old_next = GST_STATE_NEXT (bin);
2934 if (old_next != GST_STATE_PLAYING) {
2935 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2936 "committing state from %s to %s, old pending %s",
2937 gst_element_state_get_name (old_state),
2938 gst_element_state_get_name (old_next),
2939 gst_element_state_get_name (pending));
2941 /* update current state */
2942 current = GST_STATE (bin) = old_next;
2944 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2945 "setting state from %s to %s, pending %s",
2946 gst_element_state_get_name (old_state),
2947 gst_element_state_get_name (old_state),
2948 gst_element_state_get_name (pending));
2949 current = old_state;
2952 /* get our toplevel state */
2953 toplevel = BIN_IS_TOPLEVEL (bin);
2955 /* see if we reached the final state. If we are not toplevel, we also have to
2956 * stop here, the parent will continue our state. */
2957 if ((pending == current) || !toplevel) {
2958 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2959 "completed state change, pending VOID");
2961 /* mark VOID pending */
2962 pending = GST_STATE_VOID_PENDING;
2963 GST_STATE_PENDING (bin) = pending;
2964 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2966 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2967 "continue state change, pending %s",
2968 gst_element_state_get_name (pending));
2970 cont = g_slice_new (BinContinueData);
2972 /* ref to the bin */
2973 cont->bin = gst_object_ref (bin);
2974 /* cookie to detect concurrent state change */
2975 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2976 /* pending target state */
2977 cont->pending = pending;
2979 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2980 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2983 if (old_next != GST_STATE_PLAYING) {
2984 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2985 state_changed = TRUE;
2988 GST_OBJECT_UNLOCK (bin);
2990 if (state_changed) {
2991 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
2995 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2996 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
2997 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3000 GST_OBJECT_LOCK (bin);
3002 /* toplevel, start continue state */
3003 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3004 bin_push_state_continue (cont);
3006 GST_DEBUG_OBJECT (bin, "state change complete");
3007 GST_STATE_BROADCAST (bin);
3013 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3018 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3019 /* if we were busy with a state change and we are requested to flag a
3020 * pending async done, we do so here */
3022 bin->priv->pending_async_done = TRUE;
3027 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3033 bin_do_eos (GstBin * bin)
3038 GST_OBJECT_LOCK (bin);
3039 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3040 * we forward the EOS message to the parent bin or application
3042 eos = GST_STATE (bin) == GST_STATE_PLAYING
3043 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3044 && is_eos (bin, &seqnum);
3045 GST_OBJECT_UNLOCK (bin);
3048 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3050 GstMessage *tmessage;
3051 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3052 gst_message_set_seqnum (tmessage, seqnum);
3053 GST_DEBUG_OBJECT (bin,
3054 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3055 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3059 /* must be called with the object lock. This function releases the lock to post
3062 bin_do_message_forward (GstBin * bin, GstMessage * message)
3064 if (bin->priv->message_forward) {
3065 GstMessage *forwarded;
3067 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3068 GST_MESSAGE_TYPE_NAME (message));
3069 GST_OBJECT_UNLOCK (bin);
3071 /* we need to convert these messages to element messages so that our parent
3072 * bin can easily ignore them and so that the application can easily
3073 * distinguish between the internally forwarded and the real messages. */
3074 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3075 gst_structure_new ("GstBinForwarded",
3076 "message", GST_TYPE_MESSAGE, message, NULL));
3078 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3080 GST_OBJECT_LOCK (bin);
3084 /* handle child messages:
3086 * This method is called synchronously when a child posts a message on
3089 * GST_MESSAGE_EOS: This message is only posted by sinks
3090 * in the PLAYING state. If all sinks posted the EOS message, post
3093 * GST_MESSAGE_STATE_DIRTY: Deprecated
3095 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3096 * element posts segment_start twice, only the last message is kept.
3098 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3099 * with the segment_done message. If there are no more segment_start
3100 * messages, post segment_done message upwards.
3102 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3103 * Whenever someone performs a duration query on the bin, we store the
3104 * result so we can answer it quicker the next time. Any element that
3105 * changes its duration marks our cached values invalid.
3106 * This message is also posted upwards. This is currently disabled
3107 * because too many elements don't post DURATION messages when the
3110 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3111 * can no longer provide a clock. The default bin behaviour is to
3112 * check if the lost clock was the one provided by the bin. If so and
3113 * we are currently in the PLAYING state, we forward the message to
3115 * This message is also generated when we remove a clock provider from
3116 * a bin. If this message is received by the application, it should
3117 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3118 * and a new base_time distribution.
3120 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3121 * can provide a clock. This mostly happens when we add a new clock
3122 * provider to the bin. The default behaviour of the bin is to mark the
3123 * currently selected clock as dirty, which will perform a clock
3124 * recalculation the next time we are asked to provide a clock.
3125 * This message is never sent to the application but is forwarded to
3128 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3129 * the state of the element and the fact that the element will need a
3130 * new base_time. This message is not forwarded to the application.
3132 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3133 * element when it posted ASYNC_START. If all elements are done, post a
3134 * ASYNC_DONE message to the parent.
3136 * OTHER: post upwards.
3139 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3142 GstMessageType type;
3143 GstMessage *tmessage;
3146 src = GST_MESSAGE_SRC (message);
3147 type = GST_MESSAGE_TYPE (message);
3149 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3150 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3151 GST_MESSAGE_TYPE_NAME (message));
3154 case GST_MESSAGE_ERROR:
3156 GST_OBJECT_LOCK (bin);
3158 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3159 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3160 GST_STATE_BROADCAST (bin);
3161 GST_OBJECT_UNLOCK (bin);
3165 case GST_MESSAGE_EOS:
3168 /* collect all eos messages from the children */
3169 GST_OBJECT_LOCK (bin);
3170 bin_do_message_forward (bin, message);
3171 /* ref message for future use */
3172 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3173 GST_OBJECT_UNLOCK (bin);
3178 case GST_MESSAGE_STATE_DIRTY:
3180 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3183 gst_message_unref (message);
3186 case GST_MESSAGE_SEGMENT_START:{
3187 gboolean post = FALSE;
3191 gst_message_parse_segment_start (message, &format, &position);
3192 seqnum = gst_message_get_seqnum (message);
3194 GST_OBJECT_LOCK (bin);
3195 bin_do_message_forward (bin, message);
3196 /* if this is the first segment-start, post to parent but not to the
3198 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3199 (GST_OBJECT_PARENT (bin) != NULL)) {
3202 /* replace any previous segment_start message from this source
3203 * with the new segment start message */
3204 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3205 GST_OBJECT_UNLOCK (bin);
3207 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3209 gst_message_set_seqnum (tmessage, seqnum);
3211 /* post segment start with initial format and position. */
3212 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3214 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3218 case GST_MESSAGE_SEGMENT_DONE:
3220 gboolean post = FALSE;
3224 gst_message_parse_segment_done (message, &format, &position);
3225 seqnum = gst_message_get_seqnum (message);
3227 GST_OBJECT_LOCK (bin);
3228 bin_do_message_forward (bin, message);
3229 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3230 /* if there are no more segment_start messages, everybody posted
3231 * a segment_done and we can post one on the bus. */
3233 /* we don't care who still has a pending segment start */
3234 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3237 /* remove all old segment_done messages */
3238 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3240 GST_OBJECT_UNLOCK (bin);
3242 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3244 gst_message_set_seqnum (tmessage, seqnum);
3246 /* post segment done with latest format and position. */
3247 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3249 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3253 case GST_MESSAGE_DURATION:
3255 /* remove all cached duration messages, next time somebody asks
3256 * for duration, we will recalculate. */
3257 GST_OBJECT_LOCK (bin);
3258 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3259 GST_OBJECT_UNLOCK (bin);
3262 case GST_MESSAGE_CLOCK_LOST:
3264 GstClock **provided_clock_p;
3265 GstElement **clock_provider_p;
3266 gboolean playing, provided, forward;
3269 gst_message_parse_clock_lost (message, &clock);
3271 GST_OBJECT_LOCK (bin);
3272 bin->clock_dirty = TRUE;
3273 /* if we lost the clock that we provided, post to parent but
3274 * only if we are PLAYING. */
3275 provided = (clock == bin->provided_clock);
3276 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3277 forward = playing & provided;
3279 GST_DEBUG_OBJECT (bin,
3280 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3281 bin->provided_clock, bin->clock_provider);
3282 provided_clock_p = &bin->provided_clock;
3283 clock_provider_p = &bin->clock_provider;
3284 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3285 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3287 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3288 provided, playing, forward);
3289 GST_OBJECT_UNLOCK (bin);
3295 gst_message_unref (message);
3298 case GST_MESSAGE_CLOCK_PROVIDE:
3302 GST_OBJECT_LOCK (bin);
3303 bin->clock_dirty = TRUE;
3304 /* a new clock is available, post to parent but not
3305 * to the application */
3306 forward = GST_OBJECT_PARENT (bin) != NULL;
3307 GST_OBJECT_UNLOCK (bin);
3313 gst_message_unref (message);
3316 case GST_MESSAGE_ASYNC_START:
3318 gboolean new_base_time;
3321 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3322 src ? GST_OBJECT_NAME (src) : "(NULL)");
3324 gst_message_parse_async_start (message, &new_base_time);
3326 GST_OBJECT_LOCK (bin);
3327 bin_do_message_forward (bin, message);
3329 /* we ignore the message if we are going to <= READY */
3330 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3331 goto ignore_start_message;
3333 /* takes ownership of the message */
3334 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3336 bin_handle_async_start (bin, new_base_time);
3337 GST_OBJECT_UNLOCK (bin);
3340 ignore_start_message:
3342 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3343 gst_element_state_get_name (target));
3344 GST_OBJECT_UNLOCK (bin);
3345 gst_message_unref (message);
3349 case GST_MESSAGE_ASYNC_DONE:
3353 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3354 src ? GST_OBJECT_NAME (src) : "(NULL)");
3356 GST_OBJECT_LOCK (bin);
3357 bin_do_message_forward (bin, message);
3359 /* ignore messages if we are shutting down */
3360 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3361 goto ignore_done_message;
3363 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3364 /* if there are no more ASYNC_START messages, everybody posted
3365 * a ASYNC_DONE and we can post one on the bus. When checking, we
3366 * don't care who still has a pending ASYNC_START */
3367 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3368 /* nothing found, remove all old ASYNC_DONE messages */
3369 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3371 GST_DEBUG_OBJECT (bin, "async elements commited");
3372 /* when we get an async done message when a state change was busy, we
3373 * need to set the pending_done flag so that at the end of the state
3374 * change we can see if we need to verify pending async elements, hence
3375 * the TRUE argument here. */
3376 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3378 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3380 GST_OBJECT_UNLOCK (bin);
3383 ignore_done_message:
3385 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3386 gst_element_state_get_name (target));
3387 GST_OBJECT_UNLOCK (bin);
3388 gst_message_unref (message);
3392 case GST_MESSAGE_STRUCTURE_CHANGE:
3396 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3398 GST_OBJECT_LOCK (bin);
3400 /* while the pad is busy, avoid following it when doing state changes.
3401 * Don't update the cookie yet, we will do that after the structure
3402 * change finished and we are ready to inspect the new updated
3404 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3407 /* a pad link/unlink ended, signal the state change iterator that we
3408 * need to resync by updating the structure_cookie. */
3409 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3410 GST_MESSAGE_STRUCTURE_CHANGE);
3411 bin->priv->structure_cookie++;
3413 GST_OBJECT_UNLOCK (bin);
3416 gst_message_unref (message);
3427 /* Send all other messages upward */
3428 GST_DEBUG_OBJECT (bin, "posting message upward");
3429 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3434 /* generic struct passed to all query fold methods */
3443 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3444 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3446 /* for duration/position we collect all durations/positions and take
3447 * the MAX of all valid results */
3449 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3457 bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
3459 if (gst_element_query (item, fold->query)) {
3462 g_value_set_boolean (ret, TRUE);
3464 gst_query_parse_duration (fold->query, NULL, &duration);
3466 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3468 if (duration > fold->max)
3469 fold->max = duration;
3472 gst_object_unref (item);
3477 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3481 gst_query_parse_duration (fold->query, &format, NULL);
3482 /* store max in query result */
3483 gst_query_set_duration (fold->query, format, fold->max);
3485 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3487 #ifdef DURATION_CACHING
3489 GST_OBJECT_LOCK (bin);
3490 bin->messages = g_list_prepend (bin->messages,
3491 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3492 GST_OBJECT_UNLOCK (bin);
3497 bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
3499 if (gst_element_query (item, fold->query)) {
3502 g_value_set_boolean (ret, TRUE);
3504 gst_query_parse_position (fold->query, NULL, &position);
3506 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3508 if (position > fold->max)
3509 fold->max = position;
3512 gst_object_unref (item);
3517 bin_query_position_done (GstBin * bin, QueryFold * fold)
3521 gst_query_parse_position (fold->query, &format, NULL);
3522 /* store max in query result */
3523 gst_query_set_position (fold->query, format, fold->max);
3525 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3529 bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
3531 if (gst_element_query (item, fold->query)) {
3532 GstClockTime min, max;
3535 gst_query_parse_latency (fold->query, &live, &min, &max);
3537 GST_DEBUG_OBJECT (item,
3538 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3539 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3541 /* for the combined latency we collect the MAX of all min latencies and
3542 * the MIN of all max latencies */
3544 if (min > fold->min)
3546 if (fold->max == -1)
3548 else if (max < fold->max)
3550 if (fold->live == FALSE)
3554 g_value_set_boolean (ret, FALSE);
3555 GST_DEBUG_OBJECT (item, "failed query");
3558 gst_object_unref (item);
3563 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3565 /* store max in query result */
3566 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3568 GST_DEBUG_OBJECT (bin,
3569 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3570 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3574 /* generic fold, return first valid result */
3576 bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
3580 if ((res = gst_element_query (item, fold->query))) {
3581 g_value_set_boolean (ret, TRUE);
3582 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3585 gst_object_unref (item);
3587 /* and stop as soon as we have a valid result */
3592 gst_bin_query (GstElement * element, GstQuery * query)
3594 GstBin *bin = GST_BIN_CAST (element);
3596 gboolean res = FALSE;
3597 GstIteratorFoldFunction fold_func;
3598 QueryInitFunction fold_init = NULL;
3599 QueryDoneFunction fold_done = NULL;
3600 QueryFold fold_data;
3603 switch (GST_QUERY_TYPE (query)) {
3604 case GST_QUERY_DURATION:
3606 #ifdef DURATION_CACHING
3610 gst_query_parse_duration (query, &qformat, NULL);
3612 /* find cached duration query */
3613 GST_OBJECT_LOCK (bin);
3614 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3615 GstMessage *message = (GstMessage *) cached->data;
3617 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3618 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3622 gst_message_parse_duration (message, &format, &duration);
3624 /* if cached same format, copy duration in query result */
3625 if (format == qformat) {
3626 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3628 GST_OBJECT_UNLOCK (bin);
3630 gst_query_set_duration (query, qformat, duration);
3636 GST_OBJECT_UNLOCK (bin);
3638 /* no cached value found, iterate and collect durations */
3639 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3640 fold_init = bin_query_min_max_init;
3641 fold_done = bin_query_duration_done;
3644 case GST_QUERY_POSITION:
3646 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3647 fold_init = bin_query_min_max_init;
3648 fold_done = bin_query_position_done;
3651 case GST_QUERY_LATENCY:
3653 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3654 fold_init = bin_query_min_max_init;
3655 fold_done = bin_query_latency_done;
3660 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3664 fold_data.query = query;
3666 /* set the result of the query to FALSE initially */
3667 g_value_init (&ret, G_TYPE_BOOLEAN);
3668 g_value_set_boolean (&ret, res);
3670 iter = gst_bin_iterate_sinks (bin);
3671 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3672 query, GST_QUERY_TYPE_NAME (query));
3675 fold_init (bin, &fold_data);
3678 GstIteratorResult ires;
3680 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3683 case GST_ITERATOR_RESYNC:
3684 gst_iterator_resync (iter);
3686 fold_init (bin, &fold_data);
3687 g_value_set_boolean (&ret, res);
3689 case GST_ITERATOR_OK:
3690 case GST_ITERATOR_DONE:
3691 res = g_value_get_boolean (&ret);
3692 if (fold_done != NULL && res)
3693 fold_done (bin, &fold_data);
3701 gst_iterator_free (iter);
3703 #ifdef DURATION_CACHING
3706 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3712 compare_name (GstElement * element, const gchar * name)
3716 GST_OBJECT_LOCK (element);
3717 eq = strcmp (GST_ELEMENT_NAME (element), name);
3718 GST_OBJECT_UNLOCK (element);
3721 gst_object_unref (element);
3727 * gst_bin_get_by_name:
3729 * @name: the element name to search for
3731 * Gets the element with the given name from a bin. This
3732 * function recurses into child bins.
3734 * Returns NULL if no element with the given name is found in the bin.
3736 * MT safe. Caller owns returned reference.
3738 * Returns: (transfer full): the #GstElement with the given name, or NULL
3741 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3743 GstIterator *children;
3746 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3748 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3749 GST_ELEMENT_NAME (bin), name);
3751 children = gst_bin_iterate_recurse (bin);
3752 result = gst_iterator_find_custom (children,
3753 (GCompareFunc) compare_name, (gpointer) name);
3754 gst_iterator_free (children);
3756 return GST_ELEMENT_CAST (result);
3760 * gst_bin_get_by_name_recurse_up:
3762 * @name: the element name to search for
3764 * Gets the element with the given name from this bin. If the
3765 * element is not found, a recursion is performed on the parent bin.
3768 * - no element with the given name is found in the bin
3770 * MT safe. Caller owns returned reference.
3772 * Returns: (transfer full): the #GstElement with the given name, or NULL
3775 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3779 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3780 g_return_val_if_fail (name != NULL, NULL);
3782 result = gst_bin_get_by_name (bin, name);
3787 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3789 if (GST_IS_BIN (parent)) {
3790 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3792 gst_object_unref (parent);
3800 compare_interface (GstElement * element, gpointer interface)
3802 GType interface_type = (GType) interface;
3805 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3808 /* we did not find the element, need to release the ref
3809 * added by the iterator */
3810 gst_object_unref (element);
3817 * gst_bin_get_by_interface:
3819 * @iface: the #GType of an interface
3821 * Looks for an element inside the bin that implements the given
3822 * interface. If such an element is found, it returns the element.
3823 * You can cast this element to the given interface afterwards. If you want
3824 * all elements that implement the interface, use
3825 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3827 * MT safe. Caller owns returned reference.
3829 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3832 gst_bin_get_by_interface (GstBin * bin, GType iface)
3834 GstIterator *children;
3837 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3838 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3840 children = gst_bin_iterate_recurse (bin);
3841 result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3843 gst_iterator_free (children);
3845 return GST_ELEMENT_CAST (result);
3849 * gst_bin_iterate_all_by_interface:
3851 * @iface: the #GType of an interface
3853 * Looks for all elements inside the bin that implements the given
3854 * interface. You can safely cast all returned elements to the given interface.
3855 * The function recurses inside child bins. The iterator will yield a series
3856 * of #GstElement that should be unreffed after use.
3858 * Each element yielded by the iterator will have its refcount increased, so
3861 * MT safe. Caller owns returned value.
3863 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3864 * in the bin implementing the given interface, or NULL
3867 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3869 GstIterator *children;
3870 GstIterator *result;
3872 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3873 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3875 children = gst_bin_iterate_recurse (bin);
3876 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3882 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
3884 gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
3886 GstBin *bin = GST_BIN_CAST (object);
3887 xmlNodePtr childlist, elementnode;
3891 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
3892 GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
3894 childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
3896 GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
3897 GST_ELEMENT_NAME (bin), bin->numchildren);
3899 children = g_list_last (bin->children);
3901 child = GST_ELEMENT_CAST (children->data);
3902 elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
3903 gst_object_save_thyself (GST_OBJECT (child), elementnode);
3904 children = g_list_previous (children);
3910 gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
3912 GstBin *bin = GST_BIN_CAST (object);
3913 xmlNodePtr field = self->xmlChildrenNode;
3914 xmlNodePtr childlist;
3917 if (!strcmp ((char *) field->name, "children")) {
3918 GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
3919 GST_ELEMENT_NAME (object));
3920 childlist = field->xmlChildrenNode;
3922 if (!strcmp ((char *) childlist->name, "element")) {
3923 /* gst_xml_make_element will gst_bin_add() the element to ourself */
3924 gst_xml_make_element (childlist, GST_OBJECT (bin));
3926 childlist = childlist->next;
3930 field = field->next;
3932 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
3933 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
3935 #endif /* GST_DISABLE_LOADSAVE */