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;
232 static void gst_bin_dispose (GObject * object);
234 static void gst_bin_set_property (GObject * object, guint prop_id,
235 const GValue * value, GParamSpec * pspec);
236 static void gst_bin_get_property (GObject * object, guint prop_id,
237 GValue * value, GParamSpec * pspec);
239 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
240 GstStateChange transition);
241 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
242 GstState * state, GstState * pending, GstClockTime timeout);
243 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
244 gboolean flag_pending);
245 static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
246 static void bin_push_state_continue (BinContinueData * data);
248 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
249 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
251 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
252 static GstIndex *gst_bin_get_index_func (GstElement * element);
254 static GstClock *gst_bin_provide_clock_func (GstElement * element);
255 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
257 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
258 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
259 static GstBusSyncReply bin_bus_handler (GstBus * bus,
260 GstMessage * message, GstBin * bin);
261 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
263 static gboolean gst_bin_do_latency_func (GstBin * bin);
265 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
266 static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
267 static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
270 static void bin_remove_messages (GstBin * bin, GstObject * src,
271 GstMessageType types);
272 static void gst_bin_continue_func (BinContinueData * data);
273 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
274 static gint bin_element_is_src (GstElement * child, GstBin * bin);
276 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
278 /* Bin signals and properties */
287 #define DEFAULT_ASYNC_HANDLING FALSE
288 #define DEFAULT_MESSAGE_FORWARD FALSE
294 PROP_MESSAGE_FORWARD,
298 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
300 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
302 #define _do_init(type) \
304 const gchar *compat; \
305 static const GInterfaceInfo iface_info = { \
306 gst_bin_child_proxy_init, \
310 g_type_add_interface_static (type, GST_TYPE_CHILD_PROXY, &iface_info); \
312 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
313 "debugging info for the 'bin' container element"); \
315 /* compatibility stuff */ \
316 compat = g_getenv ("GST_COMPAT"); \
317 if (compat != NULL) { \
318 if (strstr (compat, "no-live-preroll")) \
319 enable_latency = FALSE; \
320 else if (strstr (compat, "live-preroll")) \
321 enable_latency = TRUE; \
325 GST_BOILERPLATE_FULL (GstBin, gst_bin, GstElement, GST_TYPE_ELEMENT, _do_init);
328 gst_bin_base_init (gpointer g_class)
330 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
332 gst_element_class_set_details_simple (gstelement_class, "Generic bin",
334 "Simple container object",
335 "Erik Walthinsen <omega@cse.ogi.edu>,"
336 "Wim Taymans <wim.taymans@gmail.com>");
340 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
346 bin = GST_BIN_CAST (child_proxy);
348 GST_OBJECT_LOCK (bin);
349 if ((res = g_list_nth_data (bin->children, index)))
350 gst_object_ref (res);
351 GST_OBJECT_UNLOCK (bin);
357 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
362 bin = GST_BIN_CAST (child_proxy);
364 GST_OBJECT_LOCK (bin);
365 num = bin->numchildren;
366 GST_OBJECT_UNLOCK (bin);
372 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
374 GstChildProxyInterface *iface = g_iface;
376 iface->get_children_count = gst_bin_child_proxy_get_children_count;
377 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
381 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
382 GValue * return_accu, const GValue * handler_return, gpointer dummy)
386 myboolean = g_value_get_boolean (handler_return);
387 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
388 g_value_set_boolean (return_accu, myboolean);
390 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
397 gst_bin_class_init (GstBinClass * klass)
399 GObjectClass *gobject_class;
400 GstObjectClass *gstobject_class;
401 GstElementClass *gstelement_class;
404 gobject_class = (GObjectClass *) klass;
405 gstobject_class = (GstObjectClass *) klass;
406 gstelement_class = (GstElementClass *) klass;
408 g_type_class_add_private (klass, sizeof (GstBinPrivate));
410 gobject_class->set_property = gst_bin_set_property;
411 gobject_class->get_property = gst_bin_get_property;
414 * GstBin:async-handling
416 * If set to #TRUE, the bin will handle asynchronous state changes.
417 * This should be used only if the bin subclass is modifying the state
418 * of its children on its own.
422 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
423 g_param_spec_boolean ("async-handling", "Async Handling",
424 "The bin will handle Asynchronous state changes",
425 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
428 * GstBin::element-added:
430 * @element: the #GstElement that was added to the bin
432 * Will be emitted after the element was added to the bin.
434 gst_bin_signals[ELEMENT_ADDED] =
435 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
436 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
437 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
439 * GstBin::element-removed:
441 * @element: the #GstElement that was removed from the bin
443 * Will be emitted after the element was removed from the bin.
445 gst_bin_signals[ELEMENT_REMOVED] =
446 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
447 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
448 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
450 * GstBin::do-latency:
453 * Will be emitted when the bin needs to perform latency calculations. This
454 * signal is only emited for toplevel bins or when async-handling is
457 * Only one signal handler is invoked. If no signals are connected, the
458 * default handler is invoked, which will query and distribute the lowest
459 * possible latency to all sinks.
461 * Connect to this signal if the default latency calculations are not
462 * sufficient, like when you need different latencies for different sinks in
467 gst_bin_signals[DO_LATENCY] =
468 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
469 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
470 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
471 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
474 * GstBin:message-forward
476 * Forward all children messages, even those that would normally be filtered by
477 * the bin. This can be interesting when one wants to be notified of the EOS
478 * state of individual elements, for example.
480 * The messages are converted to an ELEMENT message with the bin as the
481 * source. The structure of the message is named 'GstBinForwarded' and contains
482 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
487 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
488 g_param_spec_boolean ("message-forward", "Message Forward",
489 "Forwards all children messages",
490 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
492 gobject_class->dispose = gst_bin_dispose;
494 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
495 gstobject_class->save_thyself =
496 ((gpointer (*)(GstObject * object,
497 gpointer self)) * GST_DEBUG_FUNCPTR (gst_bin_save_thyself));
498 gstobject_class->restore_thyself =
499 ((void (*)(GstObject * object,
500 gpointer self)) *GST_DEBUG_FUNCPTR (gst_bin_restore_thyself));
503 gstelement_class->change_state =
504 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
505 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
506 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
507 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
508 gstelement_class->provide_clock =
509 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
510 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
512 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
513 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
515 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
516 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
517 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
519 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
521 GST_DEBUG ("creating bin thread pool");
524 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
526 g_critical ("could alloc threadpool %s", err->message);
531 gst_bin_init (GstBin * bin, GstBinClass * klass)
535 bin->numchildren = 0;
536 bin->children = NULL;
537 bin->children_cookie = 0;
538 bin->messages = NULL;
539 bin->provided_clock = NULL;
540 bin->clock_dirty = FALSE;
542 /* Set up a bus for listening to child elements */
543 bus = gst_bus_new ();
544 bin->child_bus = bus;
545 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
547 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
548 _priv_gst_bus_set_child_mode (bus);
550 bin->priv = GST_BIN_GET_PRIVATE (bin);
551 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
552 bin->priv->structure_cookie = 0;
553 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
557 gst_bin_dispose (GObject * object)
559 GstBin *bin = GST_BIN_CAST (object);
560 GstBus **child_bus_p = &bin->child_bus;
561 GstClock **provided_clock_p = &bin->provided_clock;
562 GstElement **clock_provider_p = &bin->clock_provider;
563 GstIndex **index_p = &bin->priv->index;
565 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
567 GST_OBJECT_LOCK (object);
568 gst_object_replace ((GstObject **) child_bus_p, NULL);
569 gst_object_replace ((GstObject **) provided_clock_p, NULL);
570 gst_object_replace ((GstObject **) clock_provider_p, NULL);
571 gst_object_replace ((GstObject **) index_p, NULL);
572 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
573 GST_OBJECT_UNLOCK (object);
575 while (bin->children) {
576 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
578 if (G_UNLIKELY (bin->children != NULL)) {
579 g_critical ("could not remove elements from bin '%s'",
580 GST_STR_NULL (GST_OBJECT_NAME (object)));
583 G_OBJECT_CLASS (parent_class)->dispose (object);
588 * @name: the name of the new bin
590 * Creates a new bin with the given name.
592 * Returns: (transfer full): a new #GstBin
595 gst_bin_new (const gchar * name)
597 return gst_element_factory_make ("bin", name);
601 gst_bin_set_property (GObject * object, guint prop_id,
602 const GValue * value, GParamSpec * pspec)
606 gstbin = GST_BIN_CAST (object);
609 case PROP_ASYNC_HANDLING:
610 GST_OBJECT_LOCK (gstbin);
611 gstbin->priv->asynchandling = g_value_get_boolean (value);
612 GST_OBJECT_UNLOCK (gstbin);
614 case PROP_MESSAGE_FORWARD:
615 GST_OBJECT_LOCK (gstbin);
616 gstbin->priv->message_forward = g_value_get_boolean (value);
617 GST_OBJECT_UNLOCK (gstbin);
620 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
626 gst_bin_get_property (GObject * object, guint prop_id,
627 GValue * value, GParamSpec * pspec)
631 gstbin = GST_BIN_CAST (object);
634 case PROP_ASYNC_HANDLING:
635 GST_OBJECT_LOCK (gstbin);
636 g_value_set_boolean (value, gstbin->priv->asynchandling);
637 GST_OBJECT_UNLOCK (gstbin);
639 case PROP_MESSAGE_FORWARD:
640 GST_OBJECT_LOCK (gstbin);
641 g_value_set_boolean (value, gstbin->priv->message_forward);
642 GST_OBJECT_UNLOCK (gstbin);
645 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
650 /* return the cached index */
652 gst_bin_get_index_func (GstElement * element)
657 bin = GST_BIN_CAST (element);
659 GST_OBJECT_LOCK (bin);
660 if ((result = bin->priv->index))
661 gst_object_ref (result);
662 GST_OBJECT_UNLOCK (bin);
667 /* set the index on all elements in this bin
672 gst_bin_set_index_func (GstElement * element, GstIndex * index)
679 bin = GST_BIN_CAST (element);
681 GST_OBJECT_LOCK (bin);
682 old = bin->priv->index;
683 if (G_UNLIKELY (old == index))
686 gst_object_ref (index);
687 bin->priv->index = index;
688 GST_OBJECT_UNLOCK (bin);
691 gst_object_unref (old);
693 it = gst_bin_iterate_elements (bin);
695 /* set the index on all elements in the bin */
700 switch (gst_iterator_next (it, &data)) {
701 case GST_ITERATOR_OK:
703 GstElement *child = GST_ELEMENT_CAST (data);
705 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
706 GST_ELEMENT_NAME (child));
707 gst_element_set_index (child, index);
709 gst_object_unref (child);
712 case GST_ITERATOR_RESYNC:
713 GST_DEBUG_OBJECT (bin, "iterator doing resync");
714 gst_iterator_resync (it);
717 case GST_ITERATOR_DONE:
718 GST_DEBUG_OBJECT (bin, "iterator done");
723 gst_iterator_free (it);
728 GST_DEBUG_OBJECT (bin, "index was already set");
729 GST_OBJECT_UNLOCK (bin);
734 /* set the clock on all elements in this bin
739 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
746 bin = GST_BIN_CAST (element);
748 it = gst_bin_iterate_elements (bin);
754 switch (gst_iterator_next (it, &data)) {
755 case GST_ITERATOR_OK:
757 GstElement *child = GST_ELEMENT_CAST (data);
759 res &= gst_element_set_clock (child, clock);
761 gst_object_unref (child);
764 case GST_ITERATOR_RESYNC:
765 GST_DEBUG_OBJECT (bin, "iterator doing resync");
766 gst_iterator_resync (it);
770 case GST_ITERATOR_DONE:
771 GST_DEBUG_OBJECT (bin, "iterator done");
776 gst_iterator_free (it);
781 /* get the clock for this bin by asking all of the children in this bin
783 * The ref of the returned clock in increased so unref after usage.
785 * We loop the elements in state order and pick the last clock we can
786 * get. This makes sure we get a clock from the source.
791 gst_bin_provide_clock_func (GstElement * element)
793 GstClock *result = NULL;
794 GstElement *provider = NULL;
798 GstClock **provided_clock_p;
799 GstElement **clock_provider_p;
801 bin = GST_BIN_CAST (element);
803 GST_OBJECT_LOCK (bin);
804 if (!bin->clock_dirty)
807 GST_DEBUG_OBJECT (bin, "finding new clock");
809 it = gst_bin_sort_iterator_new (bin);
811 while (it->next (it, &val) == GST_ITERATOR_OK) {
812 GstElement *child = GST_ELEMENT_CAST (val);
815 clock = gst_element_provide_clock (child);
817 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
818 clock, GST_ELEMENT_NAME (child));
820 gst_object_unref (result);
821 gst_object_unref (provider);
826 gst_object_unref (child);
830 provided_clock_p = &bin->provided_clock;
831 clock_provider_p = &bin->clock_provider;
832 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
833 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
834 bin->clock_dirty = FALSE;
835 GST_DEBUG_OBJECT (bin,
836 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
838 /* Provider is not being returned to caller, just the result */
840 gst_object_unref (provider);
841 GST_OBJECT_UNLOCK (bin);
843 gst_iterator_free (it);
849 if ((result = bin->provided_clock))
850 gst_object_ref (result);
851 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
852 GST_OBJECT_UNLOCK (bin);
859 * functions for manipulating cached messages
864 GstMessageType types;
867 /* check if a message is of given src and type */
869 message_check (GstMessage * message, MessageFind * target)
874 eq &= GST_MESSAGE_SRC (message) == target->src;
876 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
877 GST_LOG ("looking at message %p: %d", message, eq);
883 find_message (GstBin * bin, GstObject * src, GstMessageType types)
891 result = g_list_find_custom (bin->messages, &find,
892 (GCompareFunc) message_check);
895 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
896 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
899 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
900 #ifndef GST_DISABLE_GST_DEBUG
904 for (i = 0; i < 32; i++)
905 if (types & (1 << i))
906 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
914 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
917 * A message that is cached and has the same SRC and type is replaced
918 * by the given message.
921 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
927 if ((src = GST_MESSAGE_SRC (message))) {
928 /* first find the previous message posted by this element */
929 if ((previous = find_message (bin, src, types))) {
930 GstMessage *previous_msg;
932 /* if we found a previous message, replace it */
933 previous_msg = previous->data;
934 previous->data = message;
936 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
937 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
938 GST_MESSAGE_TYPE_NAME (message));
940 gst_message_unref (previous_msg);
942 /* keep new message */
943 bin->messages = g_list_prepend (bin->messages, message);
945 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
946 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
949 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
950 GST_MESSAGE_TYPE_NAME (message));
952 gst_message_unref (message);
957 /* with LOCK. Remove all messages of given types */
959 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
967 for (walk = bin->messages; walk; walk = next) {
968 GstMessage *message = (GstMessage *) walk->data;
970 next = g_list_next (walk);
972 if (message_check (message, &find) == 0) {
973 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
974 "deleting message %p of types 0x%08x", message, types);
975 bin->messages = g_list_delete_link (bin->messages, walk);
976 gst_message_unref (message);
978 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
979 "not deleting message %p of type 0x%08x", message,
980 GST_MESSAGE_TYPE (message));
986 /* Check if the bin is EOS. We do this by scanning all sinks and
987 * checking if they posted an EOS message.
989 * call with bin LOCK */
991 is_eos (GstBin * bin)
997 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1000 element = GST_ELEMENT_CAST (walk->data);
1001 if (bin_element_is_sink (element, bin) == 0) {
1002 /* check if element posted EOS */
1003 if (find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS)) {
1004 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1006 GST_DEBUG ("sink '%s' did not post EOS yet",
1007 GST_ELEMENT_NAME (element));
1017 unlink_pads (GstPad * pad)
1021 if ((peer = gst_pad_get_peer (pad))) {
1022 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1023 gst_pad_unlink (pad, peer);
1025 gst_pad_unlink (peer, pad);
1026 gst_object_unref (peer);
1028 gst_object_unref (pad);
1031 /* vmethod that adds an element to a bin
1036 gst_bin_add_func (GstBin * bin, GstElement * element)
1040 gboolean is_sink, is_source;
1041 GstMessage *clock_message = NULL, *async_message = NULL;
1042 GstStateChangeReturn ret;
1044 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1046 /* we obviously can't add ourself to ourself */
1047 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1050 /* get the element name to make sure it is unique in this bin. */
1051 GST_OBJECT_LOCK (element);
1052 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1053 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1054 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1055 GST_OBJECT_UNLOCK (element);
1057 GST_OBJECT_LOCK (bin);
1059 /* then check to see if the element's name is already taken in the bin,
1060 * we can safely take the lock here. This check is probably bogus because
1061 * you can safely change the element name after this check and before setting
1062 * the object parent. The window is very small though... */
1063 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1064 goto duplicate_name;
1066 /* set the element's parent and add the element to the bin's list of children */
1067 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1068 GST_OBJECT_CAST (bin))))
1071 /* if we add a sink we become a sink */
1073 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1075 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1078 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1080 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1082 if (gst_element_provides_clock (element)) {
1083 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1085 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1088 bin->children = g_list_prepend (bin->children, element);
1090 bin->children_cookie++;
1091 bin->priv->structure_cookie++;
1093 /* distribute the bus */
1094 gst_element_set_bus (element, bin->child_bus);
1096 /* propagate the current base_time, start_time and clock */
1097 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1098 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1099 /* it's possible that the element did not accept the clock but
1100 * that is not important right now. When the pipeline goes to PLAYING,
1101 * a new clock will be selected */
1102 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1103 /* set the cached index on the children */
1104 if (bin->priv->index)
1105 gst_element_set_index (element, bin->priv->index);
1107 ret = GST_STATE_RETURN (bin);
1108 /* no need to update the state if we are in error */
1109 if (ret == GST_STATE_CHANGE_FAILURE)
1110 goto no_state_recalc;
1112 /* update the bin state, the new element could have been an ASYNC or
1113 * NO_PREROLL element */
1114 ret = GST_STATE_RETURN (element);
1115 GST_DEBUG_OBJECT (bin, "added %s element",
1116 gst_element_state_change_return_get_name (ret));
1119 case GST_STATE_CHANGE_ASYNC:
1121 /* create message to track this aync element when it posts an async-done
1124 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1127 case GST_STATE_CHANGE_NO_PREROLL:
1128 /* ignore all async elements we might have and commit our state */
1129 bin_handle_async_done (bin, ret, FALSE);
1131 case GST_STATE_CHANGE_FAILURE:
1138 GST_OBJECT_UNLOCK (bin);
1140 /* post the messages on the bus of the element so that the bin can handle
1143 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1146 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1148 /* unlink all linked pads */
1149 it = gst_element_iterate_pads (element);
1150 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1151 gst_iterator_free (it);
1153 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1157 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1158 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1162 /* ERROR handling here */
1165 GST_OBJECT_LOCK (bin);
1166 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1167 GST_OBJECT_UNLOCK (bin);
1172 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1173 elem_name, GST_ELEMENT_NAME (bin));
1174 GST_OBJECT_UNLOCK (bin);
1180 g_warning ("Element '%s' already has parent", elem_name);
1181 GST_OBJECT_UNLOCK (bin);
1190 * @element: (transfer full): the #GstElement to add
1192 * Adds the given element to the bin. Sets the element's parent, and thus
1193 * takes ownership of the element. An element can only be added to one bin.
1195 * If the element's pads are linked to other pads, the pads will be unlinked
1196 * before the element is added to the bin.
1199 * When you add an element to an already-running pipeline, you will have to
1200 * take care to set the state of the newly-added element to the desired
1201 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1202 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1203 * The bin or pipeline will not take care of this for you.
1208 * Returns: TRUE if the element could be added, FALSE if
1209 * the bin does not want to accept the element.
1212 gst_bin_add (GstBin * bin, GstElement * element)
1214 GstBinClass *bclass;
1217 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1218 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1220 bclass = GST_BIN_GET_CLASS (bin);
1222 if (G_UNLIKELY (bclass->add_element == NULL))
1225 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1226 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1227 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1229 result = bclass->add_element (bin, element);
1233 /* ERROR handling */
1236 g_warning ("adding elements to bin '%s' is not supported",
1237 GST_ELEMENT_NAME (bin));
1242 /* remove an element from the bin
1247 gst_bin_remove_func (GstBin * bin, GstElement * element)
1251 gboolean is_sink, is_source, othersink, othersource, found;
1252 GstMessage *clock_message = NULL;
1253 GstClock **provided_clock_p;
1254 GstElement **clock_provider_p;
1256 gboolean other_async, this_async, have_no_preroll;
1257 GstStateChangeReturn ret;
1259 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1261 GST_OBJECT_LOCK (element);
1262 /* Check if the element is already being removed and immediately
1264 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1265 goto already_removing;
1267 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1268 /* grab element name so we can print it */
1269 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1270 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1271 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1272 GST_OBJECT_UNLOCK (element);
1274 /* unlink all linked pads */
1275 it = gst_element_iterate_pads (element);
1276 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1277 gst_iterator_free (it);
1279 GST_OBJECT_LOCK (bin);
1282 othersource = FALSE;
1283 have_no_preroll = FALSE;
1284 /* iterate the elements, we collect which ones are async and no_preroll. We
1285 * also remove the element when we find it. */
1286 for (walk = bin->children; walk; walk = next) {
1287 GstElement *child = GST_ELEMENT_CAST (walk->data);
1289 next = g_list_next (walk);
1291 if (child == element) {
1293 /* remove the element */
1294 bin->children = g_list_delete_link (bin->children, walk);
1296 gboolean child_sink, child_source;
1298 GST_OBJECT_LOCK (child);
1299 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1300 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1301 /* when we remove a sink, check if there are other sinks. */
1302 if (is_sink && !othersink && child_sink)
1304 if (is_source && !othersource && child_source)
1306 /* check if we have NO_PREROLL children */
1307 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1308 have_no_preroll = TRUE;
1309 GST_OBJECT_UNLOCK (child);
1313 /* the element must have been in the bin's list of children */
1314 if (G_UNLIKELY (!found))
1317 /* we now removed the element from the list of elements, increment the cookie
1318 * so that others can detect a change in the children list. */
1320 bin->children_cookie++;
1321 bin->priv->structure_cookie++;
1323 if (is_sink && !othersink) {
1324 /* we're not a sink anymore */
1325 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1326 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1328 if (is_source && !othersource) {
1329 /* we're not a source anymore */
1330 GST_DEBUG_OBJECT (bin, "we removed the last source");
1331 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1335 /* if the clock provider for this element is removed, we lost
1336 * the clock as well, we need to inform the parent of this
1337 * so that it can select a new clock */
1338 if (bin->clock_provider == element) {
1339 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1340 bin->clock_dirty = TRUE;
1342 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1343 provided_clock_p = &bin->provided_clock;
1344 clock_provider_p = &bin->clock_provider;
1345 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1346 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1349 /* remove messages for the element, if there was a pending ASYNC_START
1350 * message we must see if removing the element caused the bin to lose its
1353 other_async = FALSE;
1354 for (walk = bin->messages; walk; walk = next) {
1355 GstMessage *message = (GstMessage *) walk->data;
1356 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1359 next = g_list_next (walk);
1362 switch (GST_MESSAGE_TYPE (message)) {
1363 case GST_MESSAGE_ASYNC_START:
1369 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1371 case GST_MESSAGE_STRUCTURE_CHANGE:
1375 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1377 /* it's unlikely that this message is still in the list of messages
1378 * because this would mean that a link/unlink is busy in another thread
1379 * while we remove the element. We still have to remove the message
1380 * because we might not receive the done message anymore when the element
1381 * is removed from the bin. */
1382 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1383 if (owner == element)
1394 /* delete all message types */
1395 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1396 message, elem_name);
1397 bin->messages = g_list_delete_link (bin->messages, walk);
1398 gst_message_unref (message);
1402 /* get last return */
1403 ret = GST_STATE_RETURN (bin);
1405 /* no need to update the state if we are in error */
1406 if (ret == GST_STATE_CHANGE_FAILURE)
1407 goto no_state_recalc;
1409 if (!other_async && this_async) {
1410 /* all other elements were not async and we removed the async one,
1411 * handle the async-done case because we are not async anymore now. */
1412 GST_DEBUG_OBJECT (bin,
1413 "we removed the last async element, have no_preroll %d",
1416 /* the current state return of the bin depends on if there are no_preroll
1417 * elements in the pipeline or not */
1418 if (have_no_preroll)
1419 ret = GST_STATE_CHANGE_NO_PREROLL;
1421 ret = GST_STATE_CHANGE_SUCCESS;
1423 bin_handle_async_done (bin, ret, FALSE);
1425 GST_DEBUG_OBJECT (bin,
1426 "recalc state preroll: %d, other async: %d, this async %d",
1427 have_no_preroll, other_async, this_async);
1429 if (have_no_preroll) {
1430 ret = GST_STATE_CHANGE_NO_PREROLL;
1431 } else if (other_async) {
1432 /* there are other async elements and we were not doing an async state
1433 * change, change our pending state and go async */
1434 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1435 GST_STATE_NEXT (bin) = GST_STATE (bin);
1436 GST_STATE_PENDING (bin) = GST_STATE (bin);
1438 ret = GST_STATE_CHANGE_ASYNC;
1440 GST_STATE_RETURN (bin) = ret;
1443 GST_OBJECT_UNLOCK (bin);
1446 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1448 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1452 gst_element_set_bus (element, NULL);
1454 /* Clear the clock we provided to the element */
1455 gst_element_set_clock (element, NULL);
1457 /* we ref here because after the _unparent() the element can be disposed
1458 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1459 gst_object_ref (element);
1460 gst_object_unparent (GST_OBJECT_CAST (element));
1462 GST_OBJECT_LOCK (element);
1463 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1464 GST_OBJECT_UNLOCK (element);
1466 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1467 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1469 /* element is really out of our control now */
1470 gst_object_unref (element);
1474 /* ERROR handling */
1477 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1478 GST_ELEMENT_NAME (bin));
1479 GST_OBJECT_UNLOCK (bin);
1485 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1486 GST_OBJECT_UNLOCK (element);
1494 * @element: (transfer none): the #GstElement to remove
1496 * Removes the element from the bin, unparenting it as well.
1497 * Unparenting the element means that the element will be dereferenced,
1498 * so if the bin holds the only reference to the element, the element
1499 * will be freed in the process of removing it from the bin. If you
1500 * want the element to still exist after removing, you need to call
1501 * gst_object_ref() before removing it from the bin.
1503 * If the element's pads are linked to other pads, the pads will be unlinked
1504 * before the element is removed from the bin.
1508 * Returns: TRUE if the element could be removed, FALSE if
1509 * the bin does not want to remove the element.
1512 gst_bin_remove (GstBin * bin, GstElement * element)
1514 GstBinClass *bclass;
1517 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1518 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1520 bclass = GST_BIN_GET_CLASS (bin);
1522 if (G_UNLIKELY (bclass->remove_element == NULL))
1525 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1526 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1528 result = bclass->remove_element (bin, element);
1532 /* ERROR handling */
1535 g_warning ("removing elements from bin '%s' is not supported",
1536 GST_ELEMENT_NAME (bin));
1541 static GstIteratorItem
1542 iterate_child (GstIterator * it, GstElement * child)
1544 gst_object_ref (child);
1545 return GST_ITERATOR_ITEM_PASS;
1549 * gst_bin_iterate_elements:
1552 * Gets an iterator for the elements in this bin.
1554 * Each element yielded by the iterator will have its refcount increased, so
1557 * MT safe. Caller owns returned value.
1559 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1562 gst_bin_iterate_elements (GstBin * bin)
1564 GstIterator *result;
1566 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1568 GST_OBJECT_LOCK (bin);
1569 /* add ref because the iterator refs the bin. When the iterator
1570 * is freed it will unref the bin again using the provided dispose
1572 gst_object_ref (bin);
1573 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1574 GST_OBJECT_GET_LOCK (bin),
1575 &bin->children_cookie,
1578 (GstIteratorItemFunction) iterate_child,
1579 (GstIteratorDisposeFunction) gst_object_unref);
1580 GST_OBJECT_UNLOCK (bin);
1585 static GstIteratorItem
1586 iterate_child_recurse (GstIterator * it, GstElement * child)
1588 gst_object_ref (child);
1589 if (GST_IS_BIN (child)) {
1590 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1592 gst_iterator_push (it, other);
1594 return GST_ITERATOR_ITEM_PASS;
1598 * gst_bin_iterate_recurse:
1601 * Gets an iterator for the elements in this bin.
1602 * This iterator recurses into GstBin children.
1604 * Each element yielded by the iterator will have its refcount increased, so
1607 * MT safe. Caller owns returned value.
1609 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1612 gst_bin_iterate_recurse (GstBin * bin)
1614 GstIterator *result;
1616 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1618 GST_OBJECT_LOCK (bin);
1619 /* add ref because the iterator refs the bin. When the iterator
1620 * is freed it will unref the bin again using the provided dispose
1622 gst_object_ref (bin);
1623 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1624 GST_OBJECT_GET_LOCK (bin),
1625 &bin->children_cookie,
1628 (GstIteratorItemFunction) iterate_child_recurse,
1629 (GstIteratorDisposeFunction) gst_object_unref);
1630 GST_OBJECT_UNLOCK (bin);
1635 /* returns 0 when TRUE because this is a GCompareFunc */
1638 bin_element_is_sink (GstElement * child, GstBin * bin)
1642 /* we lock the child here for the remainder of the function to
1643 * get its name and flag safely. */
1644 GST_OBJECT_LOCK (child);
1645 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1647 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1648 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1650 GST_OBJECT_UNLOCK (child);
1651 return is_sink ? 0 : 1;
1655 sink_iterator_filter (GstElement * child, GstBin * bin)
1657 if (bin_element_is_sink (child, bin) == 0) {
1658 /* returns 0 because this is a GCompareFunc */
1661 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1663 gst_object_unref (child);
1669 * gst_bin_iterate_sinks:
1672 * Gets an iterator for all elements in the bin that have the
1673 * #GST_ELEMENT_IS_SINK flag set.
1675 * Each element yielded by the iterator will have its refcount increased, so
1678 * MT safe. Caller owns returned value.
1680 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1683 gst_bin_iterate_sinks (GstBin * bin)
1685 GstIterator *children;
1686 GstIterator *result;
1688 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1690 children = gst_bin_iterate_elements (bin);
1691 result = gst_iterator_filter (children,
1692 (GCompareFunc) sink_iterator_filter, bin);
1697 /* returns 0 when TRUE because this is a GCompareFunc */
1700 bin_element_is_src (GstElement * child, GstBin * bin)
1704 /* we lock the child here for the remainder of the function to
1705 * get its name and other info safely. */
1706 GST_OBJECT_LOCK (child);
1707 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1709 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1710 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1712 GST_OBJECT_UNLOCK (child);
1713 return is_src ? 0 : 1;
1717 src_iterator_filter (GstElement * child, GstBin * bin)
1719 if (bin_element_is_src (child, bin) == 0) {
1720 /* returns 0 because this is a GCompareFunc */
1723 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1725 gst_object_unref (child);
1731 * gst_bin_iterate_sources:
1734 * Gets an iterator for all elements in the bin that have the
1735 * #GST_ELEMENT_IS_SOURCE flag set.
1737 * Each element yielded by the iterator will have its refcount increased, so
1740 * MT safe. Caller owns returned value.
1742 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1745 gst_bin_iterate_sources (GstBin * bin)
1747 GstIterator *children;
1748 GstIterator *result;
1750 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1752 children = gst_bin_iterate_elements (bin);
1753 result = gst_iterator_filter (children,
1754 (GCompareFunc) src_iterator_filter, bin);
1762 static GstStateChangeReturn
1763 gst_bin_get_state_func (GstElement * element, GstState * state,
1764 GstState * pending, GstClockTime timeout)
1766 GstStateChangeReturn ret;
1768 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1770 ret = parent_class->get_state (element, state, pending, timeout);
1775 /***********************************************
1776 * Topologically sorted iterator
1777 * see http://en.wikipedia.org/wiki/Topological_sorting
1779 * For each element in the graph, an entry is kept in a HashTable
1780 * with its number of srcpad connections (degree).
1781 * We then change state of all elements without dependencies
1782 * (degree 0) and decrement the degree of all elements connected
1783 * on the sinkpads. When an element reaches degree 0, its state is
1785 * When all elements are handled the algorithm stops.
1787 typedef struct _GstBinSortIterator
1790 GQueue *queue; /* elements queued for state change */
1791 GstBin *bin; /* bin we iterate */
1792 gint mode; /* adding or removing dependency */
1793 GstElement *best; /* next element with least dependencies */
1794 gint best_deg; /* best degree */
1795 GHashTable *hash; /* hashtable with element dependencies */
1796 gboolean dirty; /* we detected structure change */
1797 } GstBinSortIterator;
1799 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1800 #define HASH_SET_DEGREE(bit, elem, deg) \
1801 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1802 #define HASH_GET_DEGREE(bit, elem) \
1803 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1805 /* add element to queue of next elements in the iterator.
1806 * We push at the tail to give higher priority elements a
1809 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1811 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1812 GST_ELEMENT_NAME (element));
1813 gst_object_ref (element);
1814 g_queue_push_tail (bit->queue, element);
1815 HASH_SET_DEGREE (bit, element, -1);
1819 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1823 if ((find = g_queue_find (bit->queue, element))) {
1824 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1825 GST_ELEMENT_NAME (element));
1827 g_queue_delete_link (bit->queue, find);
1828 gst_object_unref (element);
1830 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1831 GST_ELEMENT_NAME (element));
1835 /* clear the queue, unref all objects as we took a ref when
1836 * we added them to the queue */
1838 clear_queue (GQueue * queue)
1842 while ((p = g_queue_pop_head (queue)))
1843 gst_object_unref (p);
1846 /* set all degrees to 0. Elements marked as a sink are
1847 * added to the queue immediatly. Since we only look at the SINK flag of the
1848 * element, it is possible that we add non-sinks to the queue. These will be
1849 * removed from the queue again when we can prove that it provides data for some
1852 reset_degree (GstElement * element, GstBinSortIterator * bit)
1856 /* sinks are added right away */
1857 GST_OBJECT_LOCK (element);
1858 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1859 GST_OBJECT_UNLOCK (element);
1862 add_to_queue (bit, element);
1864 /* others are marked with 0 and handled when sinks are done */
1865 HASH_SET_DEGREE (bit, element, 0);
1869 /* adjust the degree of all elements connected to the given
1870 * element. If a degree of an element drops to 0, it is
1871 * added to the queue of elements to schedule next.
1873 * We have to make sure not to cross the bin boundary this element
1877 update_degree (GstElement * element, GstBinSortIterator * bit)
1879 gboolean linked = FALSE;
1881 GST_OBJECT_LOCK (element);
1882 /* don't touch degree if element has no sinkpads */
1883 if (element->numsinkpads != 0) {
1884 /* loop over all sinkpads, decrement degree for all connected
1885 * elements in this bin */
1888 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1891 pad = GST_PAD_CAST (pads->data);
1893 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1894 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1895 GST_MESSAGE_STRUCTURE_CHANGE))) {
1896 /* mark the iterator as dirty because we won't be updating the degree
1897 * of the peer parent now. This would result in the 'loop detected'
1898 * later on because the peer parent element could become the best next
1899 * element with a degree > 0. We will simply continue our state
1900 * changes and we'll eventually resync when the unlink completed and
1901 * the iterator cookie is updated. */
1906 if ((peer = gst_pad_get_peer (pad))) {
1907 GstElement *peer_element;
1909 if ((peer_element = gst_pad_get_parent_element (peer))) {
1910 GST_OBJECT_LOCK (peer_element);
1911 /* check that we don't go outside of this bin */
1912 if (GST_OBJECT_CAST (peer_element)->parent ==
1913 GST_OBJECT_CAST (bit->bin)) {
1914 gint old_deg, new_deg;
1916 old_deg = HASH_GET_DEGREE (bit, peer_element);
1918 /* check to see if we added an element as sink that was not really a
1919 * sink because it was connected to some other element. */
1920 if (old_deg == -1) {
1921 remove_from_queue (bit, peer_element);
1924 new_deg = old_deg + bit->mode;
1926 GST_DEBUG_OBJECT (bit->bin,
1927 "change element %s, degree %d->%d, linked to %s",
1928 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1929 GST_ELEMENT_NAME (element));
1931 /* update degree, it is possible that an element was in 0 and
1932 * reaches -1 here. This would mean that the element had no sinkpads
1933 * but became linked while the state change was happening. We will
1934 * resync on this with the structure change message. */
1936 /* degree hit 0, add to queue */
1937 add_to_queue (bit, peer_element);
1939 HASH_SET_DEGREE (bit, peer_element, new_deg);
1943 GST_OBJECT_UNLOCK (peer_element);
1944 gst_object_unref (peer_element);
1946 gst_object_unref (peer);
1951 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1952 GST_ELEMENT_NAME (element));
1954 GST_OBJECT_UNLOCK (element);
1957 /* find the next best element not handled yet. This is the one
1958 * with the lowest non-negative degree */
1960 find_element (GstElement * element, GstBinSortIterator * bit)
1964 /* element is already handled */
1965 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1968 /* first element or element with smaller degree */
1969 if (bit->best == NULL || bit->best_deg > degree) {
1970 bit->best = element;
1971 bit->best_deg = degree;
1975 /* get next element in iterator. the returned element has the
1976 * refcount increased */
1977 static GstIteratorResult
1978 gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
1980 GstBin *bin = bit->bin;
1982 /* empty queue, we have to find a next best element */
1983 if (g_queue_is_empty (bit->queue)) {
1987 bit->best_deg = G_MAXINT;
1988 g_list_foreach (bin->children, (GFunc) find_element, bit);
1989 if ((best = bit->best)) {
1990 /* when we detected an unlink, don't warn because our degrees might be
1991 * screwed up. We will resync later */
1992 if (bit->best_deg != 0 && !bit->dirty) {
1993 /* we don't fail on this one yet */
1994 GST_WARNING_OBJECT (bin, "loop dected in graph");
1995 g_warning ("loop detected in the graph of bin '%s'!!",
1996 GST_ELEMENT_NAME (bin));
1998 /* best unhandled element, schedule as next element */
1999 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2000 GST_ELEMENT_NAME (best));
2001 gst_object_ref (best);
2002 HASH_SET_DEGREE (bit, best, -1);
2005 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2006 /* no more unhandled elements, we are done */
2007 return GST_ITERATOR_DONE;
2010 /* everything added to the queue got reffed */
2011 *result = g_queue_pop_head (bit->queue);
2014 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
2015 /* update degrees of linked elements */
2016 update_degree (GST_ELEMENT_CAST (*result), bit);
2018 return GST_ITERATOR_OK;
2021 /* clear queues, recalculate the degrees and restart. */
2023 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2025 GstBin *bin = bit->bin;
2027 GST_DEBUG_OBJECT (bin, "resync");
2029 clear_queue (bit->queue);
2031 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2032 /* calc degrees, incrementing */
2034 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2035 /* for the rest of the function we decrement the degrees */
2039 /* clear queues, unref bin and free iterator. */
2041 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2043 GstBin *bin = bit->bin;
2045 GST_DEBUG_OBJECT (bin, "free");
2046 clear_queue (bit->queue);
2047 g_queue_free (bit->queue);
2048 g_hash_table_destroy (bit->hash);
2049 gst_object_unref (bin);
2053 /* should be called with the bin LOCK held */
2054 static GstIterator *
2055 gst_bin_sort_iterator_new (GstBin * bin)
2057 GstBinSortIterator *result;
2059 /* we don't need an ItemFunction because we ref the items in the _next
2061 result = (GstBinSortIterator *)
2062 gst_iterator_new (sizeof (GstBinSortIterator),
2064 GST_OBJECT_GET_LOCK (bin),
2065 &bin->priv->structure_cookie,
2066 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2067 (GstIteratorItemFunction) NULL,
2068 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2069 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2070 result->queue = g_queue_new ();
2071 result->hash = g_hash_table_new (NULL, NULL);
2072 gst_object_ref (bin);
2074 gst_bin_sort_iterator_resync (result);
2076 return (GstIterator *) result;
2080 * gst_bin_iterate_sorted:
2083 * Gets an iterator for the elements in this bin in topologically
2084 * sorted order. This means that the elements are returned from
2085 * the most downstream elements (sinks) to the sources.
2087 * This function is used internally to perform the state changes
2088 * of the bin elements and for clock selection.
2090 * Each element yielded by the iterator will have its refcount increased, so
2093 * MT safe. Caller owns returned value.
2095 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2098 gst_bin_iterate_sorted (GstBin * bin)
2100 GstIterator *result;
2102 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2104 GST_OBJECT_LOCK (bin);
2105 result = gst_bin_sort_iterator_new (bin);
2106 GST_OBJECT_UNLOCK (bin);
2111 static GstStateChangeReturn
2112 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2113 GstClockTime base_time, GstClockTime start_time, GstState current,
2116 GstStateChangeReturn ret;
2117 GstState pending, child_current, child_pending;
2121 GST_STATE_LOCK (element);
2123 GST_OBJECT_LOCK (element);
2124 /* set base_time and start time on child */
2125 GST_ELEMENT_START_TIME (element) = start_time;
2126 element->base_time = base_time;
2127 /* peel off the locked flag */
2128 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2129 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2130 ret = GST_STATE_RETURN (element);
2131 child_current = GST_STATE (element);
2132 child_pending = GST_STATE_PENDING (element);
2133 GST_OBJECT_UNLOCK (element);
2135 /* skip locked elements */
2136 if (G_UNLIKELY (locked))
2139 /* if the element was no preroll, just start changing the state regardless
2140 * if it had async elements (in the case of a bin) because they won't preroll
2142 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2143 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2147 GST_OBJECT_LOCK (bin);
2148 pending = GST_STATE_PENDING (bin);
2150 /* Try not to change the state of elements that are already in the state we're
2152 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2153 (child_pending == GST_STATE_VOID_PENDING &&
2154 ((pending > child_current && next > child_current) ||
2155 (pending < child_current && next < child_current)))))
2158 /* the element was busy with an upwards async state change, we must wait for
2159 * an ASYNC_DONE message before we attemp to change the state. */
2161 find_message (bin, GST_OBJECT_CAST (element),
2162 GST_MESSAGE_ASYNC_START))) {
2163 #ifndef GST_DISABLE_GST_DEBUG
2164 GstMessage *message = GST_MESSAGE_CAST (found->data);
2166 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2167 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2169 /* only wait for upward state changes */
2170 if (next > current) {
2171 /* We found an async element check if we can force its state to change or
2172 * if we have to wait for it to preroll. */
2173 if (G_UNLIKELY (!enable_latency)) {
2174 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2175 "\tto preroll in order to perform correct latency calculations.\n"
2176 "\tPlease verify that the application continues to work correctly by\n"
2177 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2178 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2185 GST_OBJECT_UNLOCK (bin);
2188 GST_DEBUG_OBJECT (bin,
2189 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2190 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2191 GST_TIME_ARGS (base_time));
2194 ret = gst_element_set_state (element, next);
2196 GST_STATE_UNLOCK (element);
2202 GST_DEBUG_OBJECT (element,
2203 "element is locked, return previous return %s",
2204 gst_element_state_change_return_get_name (ret));
2205 GST_STATE_UNLOCK (element);
2210 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2211 GST_OBJECT_UNLOCK (bin);
2212 GST_STATE_UNLOCK (element);
2213 return GST_STATE_CHANGE_ASYNC;
2217 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2218 "skipping transition from %s to %s, since bin pending"
2219 " is %s : last change state return follows",
2220 gst_element_state_get_name (child_current),
2221 gst_element_state_get_name (next),
2222 gst_element_state_get_name (pending));
2223 GST_OBJECT_UNLOCK (bin);
2224 GST_STATE_UNLOCK (element);
2229 /* gst_iterator_fold functions for pads_activate
2230 * Note how we don't stop the iterator when we fail an activation. This is
2231 * probably a FIXME since when one pad activation fails, we don't want to
2232 * continue our state change. */
2234 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2236 if (!gst_pad_set_active (pad, *active))
2237 g_value_set_boolean (ret, FALSE);
2239 gst_pad_set_caps (pad, NULL);
2241 /* unref the object that was reffed for us by _fold */
2242 gst_object_unref (pad);
2246 /* returns false on error or early cutout (will never happen because the fold
2247 * function always returns TRUE, see FIXME above) of the fold, true if all
2248 * pads in @iter were (de)activated successfully. */
2250 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2252 GstIteratorResult ires;
2255 /* no need to unset this later, it's just a boolean */
2256 g_value_init (&ret, G_TYPE_BOOLEAN);
2257 g_value_set_boolean (&ret, TRUE);
2260 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2263 case GST_ITERATOR_RESYNC:
2264 /* need to reset the result again */
2265 g_value_set_boolean (&ret, TRUE);
2266 gst_iterator_resync (iter);
2268 case GST_ITERATOR_DONE:
2269 /* all pads iterated, return collected value */
2272 /* iterator returned _ERROR or premature end with _OK,
2273 * mark an error and exit */
2274 g_value_set_boolean (&ret, FALSE);
2279 /* return collected value */
2280 return g_value_get_boolean (&ret);
2283 /* is called with STATE_LOCK
2286 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2291 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2293 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2294 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2295 gst_iterator_free (iter);
2296 if (G_UNLIKELY (!fold_ok))
2299 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2306 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2312 * gst_bin_recalculate_latency:
2315 * Query @bin for the current latency using and reconfigures this latency to all the
2316 * elements with a LATENCY event.
2318 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2319 * is posted on the bus.
2321 * This function simply emits the 'do-latency' signal so any custom latency
2322 * calculations will be performed.
2324 * Returns: %TRUE if the latency could be queried and reconfigured.
2329 gst_bin_recalculate_latency (GstBin * bin)
2333 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2334 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2340 gst_bin_do_latency_func (GstBin * bin)
2343 GstElement *element;
2344 GstClockTime min_latency, max_latency;
2347 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2349 element = GST_ELEMENT_CAST (bin);
2351 GST_DEBUG_OBJECT (element, "querying latency");
2353 query = gst_query_new_latency ();
2354 if ((res = gst_element_query (element, query))) {
2357 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2359 GST_DEBUG_OBJECT (element,
2360 "got min latency %" GST_TIME_FORMAT ", max latency %"
2361 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2362 GST_TIME_ARGS (max_latency), live);
2364 if (max_latency < min_latency) {
2365 /* this is an impossible situation, some parts of the pipeline might not
2366 * work correctly. We post a warning for now. */
2367 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2368 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2369 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2370 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2373 /* configure latency on elements */
2374 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2376 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2377 GST_TIME_ARGS (min_latency));
2379 GST_WARNING_OBJECT (element,
2380 "did not really configure latency of %" GST_TIME_FORMAT,
2381 GST_TIME_ARGS (min_latency));
2384 /* this is not a real problem, we just don't configure any latency. */
2385 GST_WARNING_OBJECT (element, "failed to query latency");
2387 gst_query_unref (query);
2392 static GstStateChangeReturn
2393 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2396 GstStateChangeReturn ret;
2397 GstState current, next;
2398 gboolean have_async;
2399 gboolean have_no_preroll;
2400 GstClockTime base_time, start_time;
2404 /* we don't need to take the STATE_LOCK, it is already taken */
2405 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2406 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2408 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2409 "changing state of children from %s to %s",
2410 gst_element_state_get_name (current), gst_element_state_get_name (next));
2412 bin = GST_BIN_CAST (element);
2415 case GST_STATE_PLAYING:
2419 GST_OBJECT_LOCK (bin);
2420 toplevel = BIN_IS_TOPLEVEL (bin);
2421 GST_OBJECT_UNLOCK (bin);
2424 gst_bin_recalculate_latency (bin);
2427 case GST_STATE_PAUSED:
2428 /* Clear EOS list on next PAUSED */
2429 GST_OBJECT_LOCK (bin);
2430 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2431 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2432 GST_OBJECT_UNLOCK (bin);
2433 if (current == GST_STATE_READY)
2434 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2435 goto activate_failure;
2437 case GST_STATE_READY:
2438 /* Clear message list on next READY */
2439 GST_OBJECT_LOCK (bin);
2440 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2441 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2442 GST_OBJECT_UNLOCK (bin);
2443 if (current == GST_STATE_PAUSED)
2444 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2445 goto activate_failure;
2447 case GST_STATE_NULL:
2448 if (current == GST_STATE_READY)
2449 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2450 goto activate_failure;
2456 /* this flag is used to make the async state changes return immediatly. We
2457 * don't want them to interfere with this state change */
2458 GST_OBJECT_LOCK (bin);
2459 bin->polling = TRUE;
2460 GST_OBJECT_UNLOCK (bin);
2462 /* iterate in state change order */
2463 it = gst_bin_iterate_sorted (bin);
2465 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2466 * Note how we don't reset this value when a resync happens, the reason being
2467 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2468 * even after a resync when the async element is gone */
2472 /* take base_time */
2473 base_time = gst_element_get_base_time (element);
2474 start_time = gst_element_get_start_time (element);
2476 have_no_preroll = FALSE;
2482 switch (gst_iterator_next (it, &data)) {
2483 case GST_ITERATOR_OK:
2487 child = GST_ELEMENT_CAST (data);
2489 /* set state and base_time now */
2490 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2494 case GST_STATE_CHANGE_SUCCESS:
2495 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2496 "child '%s' changed state to %d(%s) successfully",
2497 GST_ELEMENT_NAME (child), next,
2498 gst_element_state_get_name (next));
2500 case GST_STATE_CHANGE_ASYNC:
2502 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2503 "child '%s' is changing state asynchronously to %s",
2504 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2508 case GST_STATE_CHANGE_FAILURE:{
2511 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2512 "child '%s' failed to go to state %d(%s)",
2513 GST_ELEMENT_NAME (child),
2514 next, gst_element_state_get_name (next));
2516 /* Only fail if the child is still inside
2517 * this bin. It might've been removed already
2518 * because of the error by the bin subclass
2519 * to ignore the error. */
2520 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2521 if (parent == GST_OBJECT_CAST (element)) {
2522 /* element is still in bin, really error now */
2523 gst_object_unref (child);
2524 gst_object_unref (parent);
2527 /* child removed from bin, let the resync code redo the state
2529 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2530 "child '%s' was removed from the bin",
2531 GST_ELEMENT_NAME (child));
2534 gst_object_unref (parent);
2538 case GST_STATE_CHANGE_NO_PREROLL:
2539 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2540 "child '%s' changed state to %d(%s) successfully without preroll",
2541 GST_ELEMENT_NAME (child), next,
2542 gst_element_state_get_name (next));
2543 have_no_preroll = TRUE;
2546 g_assert_not_reached ();
2549 gst_object_unref (child);
2552 case GST_ITERATOR_RESYNC:
2553 GST_CAT_DEBUG (GST_CAT_STATES, "iterator doing resync");
2554 gst_iterator_resync (it);
2557 case GST_ITERATOR_DONE:
2558 GST_CAT_DEBUG (GST_CAT_STATES, "iterator done");
2564 ret = parent_class->change_state (element, transition);
2565 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2568 if (have_no_preroll) {
2569 GST_CAT_DEBUG (GST_CAT_STATES,
2570 "we have NO_PREROLL elements %s -> NO_PREROLL",
2571 gst_element_state_change_return_get_name (ret));
2572 ret = GST_STATE_CHANGE_NO_PREROLL;
2573 } else if (have_async) {
2574 GST_CAT_DEBUG (GST_CAT_STATES, "we have ASYNC elements %s -> ASYNC",
2575 gst_element_state_change_return_get_name (ret));
2576 ret = GST_STATE_CHANGE_ASYNC;
2580 gst_iterator_free (it);
2582 GST_OBJECT_LOCK (bin);
2583 bin->polling = FALSE;
2584 /* it's possible that we did not get ASYNC from the children while the bin is
2585 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2586 * itself as the source. In that case we still want to check if the state
2587 * change completed. */
2588 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2589 /* no element returned ASYNC and there are no pending async_done messages,
2590 * we can just complete. */
2591 GST_DEBUG_OBJECT (bin, "no async elements");
2594 /* when we get here an ASYNC element was found */
2595 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2596 /* we ignore ASYNC state changes when we go to READY or NULL */
2597 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2598 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2602 GST_DEBUG_OBJECT (bin, "check async elements");
2603 /* check if all elements managed to commit their state already */
2604 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2605 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2606 * all the elements commited their state while we were doing the state
2607 * change. We will still return ASYNC for consistency but we commit the
2608 * state already so that a _get_state() will return immediatly. */
2609 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2611 GST_DEBUG_OBJECT (bin, "async elements commited");
2612 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2616 bin->priv->pending_async_done = FALSE;
2617 GST_OBJECT_UNLOCK (bin);
2619 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2620 "done changing bin's state from %s to %s, now in %s, ret %s",
2621 gst_element_state_get_name (current),
2622 gst_element_state_get_name (next),
2623 gst_element_state_get_name (GST_STATE (element)),
2624 gst_element_state_change_return_get_name (ret));
2631 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2632 "failure (de)activating src pads");
2633 return GST_STATE_CHANGE_FAILURE;
2638 * This function is a utility event handler for seek events.
2639 * It will send the event to all sinks or sources depending on the
2642 * Applications are free to override this behaviour and
2643 * implement their own seek handler, but this will work for
2644 * pretty much all cases in practice.
2647 gst_bin_send_event (GstElement * element, GstEvent * event)
2649 GstBin *bin = GST_BIN_CAST (element);
2651 gboolean res = TRUE;
2652 gboolean done = FALSE;
2654 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2655 iter = gst_bin_iterate_sources (bin);
2656 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2657 GST_EVENT_TYPE_NAME (event));
2659 iter = gst_bin_iterate_sinks (bin);
2660 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2661 GST_EVENT_TYPE_NAME (event));
2667 switch (gst_iterator_next (iter, &data)) {
2668 case GST_ITERATOR_OK:
2672 gst_event_ref (event);
2673 child = GST_ELEMENT_CAST (data);
2674 res &= gst_element_send_event (child, event);
2675 gst_object_unref (child);
2678 case GST_ITERATOR_RESYNC:
2679 gst_iterator_resync (iter);
2682 case GST_ITERATOR_DONE:
2685 case GST_ITERATOR_ERROR:
2686 g_assert_not_reached ();
2690 gst_iterator_free (iter);
2691 gst_event_unref (event);
2696 /* this is the function called by the threadpool. When async elements commit
2697 * their state, this function will attempt to bring the bin to the next state.
2700 gst_bin_continue_func (BinContinueData * data)
2703 GstState current, next, pending;
2704 GstStateChange transition;
2707 pending = data->pending;
2709 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2710 GST_STATE_LOCK (bin);
2712 GST_DEBUG_OBJECT (bin, "doing state continue");
2713 GST_OBJECT_LOCK (bin);
2715 /* if a new state change happened after this thread was scheduled, we return
2717 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2720 current = GST_STATE (bin);
2721 next = GST_STATE_GET_NEXT (current, pending);
2722 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2724 GST_STATE_NEXT (bin) = next;
2725 GST_STATE_PENDING (bin) = pending;
2727 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2728 GST_OBJECT_UNLOCK (bin);
2730 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2731 "continue state change %s to %s, final %s",
2732 gst_element_state_get_name (current),
2733 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2735 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2737 GST_STATE_UNLOCK (bin);
2738 GST_DEBUG_OBJECT (bin, "state continue done");
2739 gst_object_unref (bin);
2740 g_slice_free (BinContinueData, data);
2745 GST_OBJECT_UNLOCK (bin);
2746 GST_STATE_UNLOCK (bin);
2747 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2748 gst_object_unref (bin);
2749 g_slice_free (BinContinueData, data);
2754 static GstBusSyncReply
2755 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2757 GstBinClass *bclass;
2759 bclass = GST_BIN_GET_CLASS (bin);
2760 if (bclass->handle_message)
2761 bclass->handle_message (bin, message);
2763 gst_message_unref (message);
2765 return GST_BUS_DROP;
2769 bin_push_state_continue (BinContinueData * data)
2776 klass = GST_BIN_GET_CLASS (bin);
2778 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2779 g_thread_pool_push (klass->pool, data, NULL);
2782 /* an element started an async state change, if we were not busy with a state
2783 * change, we perform a lost state.
2784 * This function is called with the OBJECT lock.
2787 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2789 GstState old_state, new_state;
2791 GstMessage *amessage = NULL;
2793 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2796 /* get our toplevel state */
2797 toplevel = BIN_IS_TOPLEVEL (bin);
2799 /* prepare an ASYNC_START message, we always post the start message even if we
2800 * are busy with a state change or when we are NO_PREROLL. */
2802 /* non toplevel bin, prepare async-start for the parent */
2804 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2806 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2809 /* async starts are ignored when we are NO_PREROLL */
2810 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2811 goto was_no_preroll;
2813 old_state = GST_STATE (bin);
2815 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2816 * PLAYING after optionally redistributing the base_time. */
2817 if (old_state > GST_STATE_PAUSED)
2818 new_state = GST_STATE_PAUSED;
2820 new_state = old_state;
2822 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2823 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2824 gst_element_state_get_name (new_state));
2826 GST_STATE (bin) = new_state;
2827 GST_STATE_NEXT (bin) = new_state;
2828 GST_STATE_PENDING (bin) = new_state;
2829 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2830 GST_OBJECT_UNLOCK (bin);
2833 gst_element_post_message (GST_ELEMENT_CAST (bin),
2834 gst_message_new_state_changed (GST_OBJECT_CAST (bin),
2835 new_state, new_state, new_state));
2839 /* post our ASYNC_START. */
2840 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2841 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2843 GST_OBJECT_LOCK (bin);
2849 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2854 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2855 GST_OBJECT_UNLOCK (bin);
2860 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2861 GST_OBJECT_UNLOCK (bin);
2866 /* this function is called when there are no more async elements in the bin. We
2867 * post a state changed message and an ASYNC_DONE message.
2868 * This function is called with the OBJECT lock.
2871 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2872 gboolean flag_pending)
2874 GstState current, pending, target;
2875 GstStateChangeReturn old_ret;
2876 GstState old_state, old_next;
2878 GstMessage *smessage = NULL, *amessage = NULL;
2879 BinContinueData *cont = NULL;
2881 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2884 pending = GST_STATE_PENDING (bin);
2889 /* check if there is something to commit */
2890 if (pending == GST_STATE_VOID_PENDING)
2891 goto nothing_pending;
2893 old_ret = GST_STATE_RETURN (bin);
2894 GST_STATE_RETURN (bin) = ret;
2896 /* move to the next target state */
2897 target = GST_STATE_TARGET (bin);
2898 pending = GST_STATE_PENDING (bin) = target;
2900 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2902 old_state = GST_STATE (bin);
2903 /* this is the state we should go to next */
2904 old_next = GST_STATE_NEXT (bin);
2906 if (old_next != GST_STATE_PLAYING) {
2907 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2908 "committing state from %s to %s, old pending %s",
2909 gst_element_state_get_name (old_state),
2910 gst_element_state_get_name (old_next),
2911 gst_element_state_get_name (pending));
2913 /* update current state */
2914 current = GST_STATE (bin) = old_next;
2916 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2917 "setting state from %s to %s, pending %s",
2918 gst_element_state_get_name (old_state),
2919 gst_element_state_get_name (old_state),
2920 gst_element_state_get_name (pending));
2921 current = old_state;
2924 /* get our toplevel state */
2925 toplevel = BIN_IS_TOPLEVEL (bin);
2927 /* see if we reached the final state. If we are not toplevel, we also have to
2928 * stop here, the parent will continue our state. */
2929 if ((pending == current) || !toplevel) {
2930 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2931 "completed state change, pending VOID");
2933 /* mark VOID pending */
2934 pending = GST_STATE_VOID_PENDING;
2935 GST_STATE_PENDING (bin) = pending;
2936 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2938 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2939 "continue state change, pending %s",
2940 gst_element_state_get_name (pending));
2942 cont = g_slice_new (BinContinueData);
2944 /* ref to the bin */
2945 cont->bin = gst_object_ref (bin);
2946 /* cookie to detect concurrent state change */
2947 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2948 /* pending target state */
2949 cont->pending = pending;
2951 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2952 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2955 if (old_next != GST_STATE_PLAYING) {
2956 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2957 smessage = gst_message_new_state_changed (GST_OBJECT_CAST (bin),
2958 old_state, old_next, pending);
2961 GST_OBJECT_UNLOCK (bin);
2964 GST_DEBUG_OBJECT (bin, "posting state change message");
2965 gst_element_post_message (GST_ELEMENT_CAST (bin), smessage);
2968 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2969 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
2970 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2973 GST_OBJECT_LOCK (bin);
2975 /* toplevel, start continue state */
2976 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
2977 bin_push_state_continue (cont);
2979 GST_DEBUG_OBJECT (bin, "state change complete");
2980 GST_STATE_BROADCAST (bin);
2986 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2991 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2992 /* if we were busy with a state change and we are requested to flag a
2993 * pending async done, we do so here */
2995 bin->priv->pending_async_done = TRUE;
3000 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3005 /* must be called with the object lock. This function releases the lock to post
3008 bin_do_message_forward (GstBin * bin, GstMessage * message)
3010 if (bin->priv->message_forward) {
3011 GstMessage *forwarded;
3013 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3014 GST_MESSAGE_TYPE_NAME (message));
3015 GST_OBJECT_UNLOCK (bin);
3017 /* we need to convert these messages to element messages so that our parent
3018 * bin can easily ignore them and so that the application can easily
3019 * distinguish between the internally forwarded and the real messages. */
3020 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3021 gst_structure_new ("GstBinForwarded",
3022 "message", GST_TYPE_MESSAGE, message, NULL));
3024 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3026 GST_OBJECT_LOCK (bin);
3030 /* handle child messages:
3032 * This method is called synchronously when a child posts a message on
3035 * GST_MESSAGE_EOS: This message is only posted by sinks
3036 * in the PLAYING state. If all sinks posted the EOS message, post
3039 * GST_MESSAGE_STATE_DIRTY: Deprecated
3041 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3042 * element posts segment_start twice, only the last message is kept.
3044 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3045 * with the segment_done message. If there are no more segment_start
3046 * messages, post segment_done message upwards.
3048 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3049 * Whenever someone performs a duration query on the bin, we store the
3050 * result so we can answer it quicker the next time. Any element that
3051 * changes its duration marks our cached values invalid.
3052 * This message is also posted upwards. This is currently disabled
3053 * because too many elements don't post DURATION messages when the
3056 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3057 * can no longer provide a clock. The default bin behaviour is to
3058 * check if the lost clock was the one provided by the bin. If so and
3059 * we are currently in the PLAYING state, we forward the message to
3061 * This message is also generated when we remove a clock provider from
3062 * a bin. If this message is received by the application, it should
3063 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3064 * and a new base_time distribution.
3066 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3067 * can provide a clock. This mostly happens when we add a new clock
3068 * provider to the bin. The default behaviour of the bin is to mark the
3069 * currently selected clock as dirty, which will perform a clock
3070 * recalculation the next time we are asked to provide a clock.
3071 * This message is never sent to the application but is forwarded to
3074 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3075 * the state of the element and the fact that the element will need a
3076 * new base_time. This message is not forwarded to the application.
3078 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3079 * element when it posted ASYNC_START. If all elements are done, post a
3080 * ASYNC_DONE message to the parent.
3082 * OTHER: post upwards.
3085 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3088 GstMessageType type;
3089 GstMessage *tmessage;
3092 src = GST_MESSAGE_SRC (message);
3093 type = GST_MESSAGE_TYPE (message);
3095 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3096 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3097 GST_MESSAGE_TYPE_NAME (message));
3100 case GST_MESSAGE_ERROR:
3102 GST_OBJECT_LOCK (bin);
3104 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3105 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3106 GST_STATE_BROADCAST (bin);
3107 GST_OBJECT_UNLOCK (bin);
3111 case GST_MESSAGE_EOS:
3115 /* collect all eos messages from the children */
3116 GST_OBJECT_LOCK (bin);
3117 bin_do_message_forward (bin, message);
3118 /* ref message for future use */
3119 gst_message_ref (message);
3120 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3122 GST_OBJECT_UNLOCK (bin);
3124 /* if we are completely EOS, we forward an EOS message */
3126 seqnum = gst_message_get_seqnum (message);
3127 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3128 gst_message_set_seqnum (tmessage, seqnum);
3130 GST_DEBUG_OBJECT (bin,
3131 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3132 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3134 gst_message_unref (message);
3137 case GST_MESSAGE_STATE_DIRTY:
3139 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3142 gst_message_unref (message);
3145 case GST_MESSAGE_SEGMENT_START:{
3146 gboolean post = FALSE;
3150 gst_message_parse_segment_start (message, &format, &position);
3151 seqnum = gst_message_get_seqnum (message);
3153 GST_OBJECT_LOCK (bin);
3154 bin_do_message_forward (bin, message);
3155 /* if this is the first segment-start, post to parent but not to the
3157 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3158 (GST_OBJECT_PARENT (bin) != NULL)) {
3161 /* replace any previous segment_start message from this source
3162 * with the new segment start message */
3163 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3164 GST_OBJECT_UNLOCK (bin);
3166 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3168 gst_message_set_seqnum (tmessage, seqnum);
3170 /* post segment start with initial format and position. */
3171 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3173 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3177 case GST_MESSAGE_SEGMENT_DONE:
3179 gboolean post = FALSE;
3183 gst_message_parse_segment_done (message, &format, &position);
3184 seqnum = gst_message_get_seqnum (message);
3186 GST_OBJECT_LOCK (bin);
3187 bin_do_message_forward (bin, message);
3188 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3189 /* if there are no more segment_start messages, everybody posted
3190 * a segment_done and we can post one on the bus. */
3192 /* we don't care who still has a pending segment start */
3193 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3196 /* remove all old segment_done messages */
3197 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3199 GST_OBJECT_UNLOCK (bin);
3201 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3203 gst_message_set_seqnum (tmessage, seqnum);
3205 /* post segment done with latest format and position. */
3206 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3208 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3212 case GST_MESSAGE_DURATION:
3214 /* remove all cached duration messages, next time somebody asks
3215 * for duration, we will recalculate. */
3216 GST_OBJECT_LOCK (bin);
3217 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3218 GST_OBJECT_UNLOCK (bin);
3221 case GST_MESSAGE_CLOCK_LOST:
3223 GstClock **provided_clock_p;
3224 GstElement **clock_provider_p;
3225 gboolean playing, provided, forward;
3228 gst_message_parse_clock_lost (message, &clock);
3230 GST_OBJECT_LOCK (bin);
3231 bin->clock_dirty = TRUE;
3232 /* if we lost the clock that we provided, post to parent but
3233 * only if we are PLAYING. */
3234 provided = (clock == bin->provided_clock);
3235 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3236 forward = playing & provided;
3238 GST_DEBUG_OBJECT (bin,
3239 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3240 bin->provided_clock, bin->clock_provider);
3241 provided_clock_p = &bin->provided_clock;
3242 clock_provider_p = &bin->clock_provider;
3243 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3244 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3246 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3247 provided, playing, forward);
3248 GST_OBJECT_UNLOCK (bin);
3254 gst_message_unref (message);
3257 case GST_MESSAGE_CLOCK_PROVIDE:
3261 GST_OBJECT_LOCK (bin);
3262 bin->clock_dirty = TRUE;
3263 /* a new clock is available, post to parent but not
3264 * to the application */
3265 forward = GST_OBJECT_PARENT (bin) != NULL;
3266 GST_OBJECT_UNLOCK (bin);
3272 gst_message_unref (message);
3275 case GST_MESSAGE_ASYNC_START:
3277 gboolean new_base_time;
3280 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3281 src ? GST_OBJECT_NAME (src) : "(NULL)");
3283 gst_message_parse_async_start (message, &new_base_time);
3285 GST_OBJECT_LOCK (bin);
3286 bin_do_message_forward (bin, message);
3288 /* we ignore the message if we are going to <= READY */
3289 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3290 goto ignore_start_message;
3292 /* takes ownership of the message */
3293 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3295 bin_handle_async_start (bin, new_base_time);
3296 GST_OBJECT_UNLOCK (bin);
3299 ignore_start_message:
3301 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3302 gst_element_state_get_name (target));
3303 GST_OBJECT_UNLOCK (bin);
3304 gst_message_unref (message);
3308 case GST_MESSAGE_ASYNC_DONE:
3312 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3313 src ? GST_OBJECT_NAME (src) : "(NULL)");
3315 GST_OBJECT_LOCK (bin);
3316 bin_do_message_forward (bin, message);
3318 /* ignore messages if we are shutting down */
3319 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3320 goto ignore_done_message;
3322 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3323 /* if there are no more ASYNC_START messages, everybody posted
3324 * a ASYNC_DONE and we can post one on the bus. When checking, we
3325 * don't care who still has a pending ASYNC_START */
3326 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3327 /* nothing found, remove all old ASYNC_DONE messages */
3328 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3330 GST_DEBUG_OBJECT (bin, "async elements commited");
3331 /* when we get an async done message when a state change was busy, we
3332 * need to set the pending_done flag so that at the end of the state
3333 * change we can see if we need to verify pending async elements, hence
3334 * the TRUE argument here. */
3335 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3337 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3339 GST_OBJECT_UNLOCK (bin);
3342 ignore_done_message:
3344 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3345 gst_element_state_get_name (target));
3346 GST_OBJECT_UNLOCK (bin);
3347 gst_message_unref (message);
3351 case GST_MESSAGE_STRUCTURE_CHANGE:
3355 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3357 GST_OBJECT_LOCK (bin);
3359 /* while the pad is busy, avoid following it when doing state changes.
3360 * Don't update the cookie yet, we will do that after the structure
3361 * change finished and we are ready to inspect the new updated
3363 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3366 /* a pad link/unlink ended, signal the state change iterator that we
3367 * need to resync by updating the structure_cookie. */
3368 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3369 GST_MESSAGE_STRUCTURE_CHANGE);
3370 bin->priv->structure_cookie++;
3372 GST_OBJECT_UNLOCK (bin);
3375 gst_message_unref (message);
3386 /* Send all other messages upward */
3387 GST_DEBUG_OBJECT (bin, "posting message upward");
3388 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3393 /* generic struct passed to all query fold methods */
3402 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3403 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3405 /* for duration/position we collect all durations/positions and take
3406 * the MAX of all valid results */
3408 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3416 bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
3418 if (gst_element_query (item, fold->query)) {
3421 g_value_set_boolean (ret, TRUE);
3423 gst_query_parse_duration (fold->query, NULL, &duration);
3425 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3427 if (duration > fold->max)
3428 fold->max = duration;
3431 gst_object_unref (item);
3436 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3440 gst_query_parse_duration (fold->query, &format, NULL);
3441 /* store max in query result */
3442 gst_query_set_duration (fold->query, format, fold->max);
3444 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3446 #ifdef DURATION_CACHING
3448 GST_OBJECT_LOCK (bin);
3449 bin->messages = g_list_prepend (bin->messages,
3450 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3451 GST_OBJECT_UNLOCK (bin);
3456 bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
3458 if (gst_element_query (item, fold->query)) {
3461 g_value_set_boolean (ret, TRUE);
3463 gst_query_parse_position (fold->query, NULL, &position);
3465 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3467 if (position > fold->max)
3468 fold->max = position;
3471 gst_object_unref (item);
3476 bin_query_position_done (GstBin * bin, QueryFold * fold)
3480 gst_query_parse_position (fold->query, &format, NULL);
3481 /* store max in query result */
3482 gst_query_set_position (fold->query, format, fold->max);
3484 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3488 bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
3490 if (gst_element_query (item, fold->query)) {
3491 GstClockTime min, max;
3494 gst_query_parse_latency (fold->query, &live, &min, &max);
3496 GST_DEBUG_OBJECT (item,
3497 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3498 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3500 /* for the combined latency we collect the MAX of all min latencies and
3501 * the MIN of all max latencies */
3503 if (min > fold->min)
3505 if (fold->max == -1)
3507 else if (max < fold->max)
3509 if (fold->live == FALSE)
3513 g_value_set_boolean (ret, FALSE);
3514 GST_DEBUG_OBJECT (item, "failed query");
3517 gst_object_unref (item);
3522 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3524 /* store max in query result */
3525 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3527 GST_DEBUG_OBJECT (bin,
3528 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3529 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3533 /* generic fold, return first valid result */
3535 bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
3539 if ((res = gst_element_query (item, fold->query))) {
3540 g_value_set_boolean (ret, TRUE);
3541 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3544 gst_object_unref (item);
3546 /* and stop as soon as we have a valid result */
3551 gst_bin_query (GstElement * element, GstQuery * query)
3553 GstBin *bin = GST_BIN_CAST (element);
3555 gboolean res = FALSE;
3556 GstIteratorFoldFunction fold_func;
3557 QueryInitFunction fold_init = NULL;
3558 QueryDoneFunction fold_done = NULL;
3559 QueryFold fold_data;
3562 switch (GST_QUERY_TYPE (query)) {
3563 case GST_QUERY_DURATION:
3565 #ifdef DURATION_CACHING
3569 gst_query_parse_duration (query, &qformat, NULL);
3571 /* find cached duration query */
3572 GST_OBJECT_LOCK (bin);
3573 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3574 GstMessage *message = (GstMessage *) cached->data;
3576 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3577 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3581 gst_message_parse_duration (message, &format, &duration);
3583 /* if cached same format, copy duration in query result */
3584 if (format == qformat) {
3585 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3587 GST_OBJECT_UNLOCK (bin);
3589 gst_query_set_duration (query, qformat, duration);
3595 GST_OBJECT_UNLOCK (bin);
3597 /* no cached value found, iterate and collect durations */
3598 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3599 fold_init = bin_query_min_max_init;
3600 fold_done = bin_query_duration_done;
3603 case GST_QUERY_POSITION:
3605 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3606 fold_init = bin_query_min_max_init;
3607 fold_done = bin_query_position_done;
3610 case GST_QUERY_LATENCY:
3612 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3613 fold_init = bin_query_min_max_init;
3614 fold_done = bin_query_latency_done;
3619 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3623 fold_data.query = query;
3625 /* set the result of the query to FALSE initially */
3626 g_value_init (&ret, G_TYPE_BOOLEAN);
3627 g_value_set_boolean (&ret, res);
3629 iter = gst_bin_iterate_sinks (bin);
3630 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3631 query, GST_QUERY_TYPE_NAME (query));
3634 fold_init (bin, &fold_data);
3637 GstIteratorResult ires;
3639 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3642 case GST_ITERATOR_RESYNC:
3643 gst_iterator_resync (iter);
3645 fold_init (bin, &fold_data);
3646 g_value_set_boolean (&ret, res);
3648 case GST_ITERATOR_OK:
3649 case GST_ITERATOR_DONE:
3650 res = g_value_get_boolean (&ret);
3651 if (fold_done != NULL && res)
3652 fold_done (bin, &fold_data);
3660 gst_iterator_free (iter);
3662 #ifdef DURATION_CACHING
3665 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3671 compare_name (GstElement * element, const gchar * name)
3675 GST_OBJECT_LOCK (element);
3676 eq = strcmp (GST_ELEMENT_NAME (element), name);
3677 GST_OBJECT_UNLOCK (element);
3680 gst_object_unref (element);
3686 * gst_bin_get_by_name:
3688 * @name: the element name to search for
3690 * Gets the element with the given name from a bin. This
3691 * function recurses into child bins.
3693 * Returns NULL if no element with the given name is found in the bin.
3695 * MT safe. Caller owns returned reference.
3697 * Returns: (transfer full): the #GstElement with the given name, or NULL
3700 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3702 GstIterator *children;
3705 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3707 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3708 GST_ELEMENT_NAME (bin), name);
3710 children = gst_bin_iterate_recurse (bin);
3711 result = gst_iterator_find_custom (children,
3712 (GCompareFunc) compare_name, (gpointer) name);
3713 gst_iterator_free (children);
3715 return GST_ELEMENT_CAST (result);
3719 * gst_bin_get_by_name_recurse_up:
3721 * @name: the element name to search for
3723 * Gets the element with the given name from this bin. If the
3724 * element is not found, a recursion is performed on the parent bin.
3727 * - no element with the given name is found in the bin
3729 * MT safe. Caller owns returned reference.
3731 * Returns: (transfer full): the #GstElement with the given name, or NULL
3734 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3738 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3739 g_return_val_if_fail (name != NULL, NULL);
3741 result = gst_bin_get_by_name (bin, name);
3746 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3748 if (GST_IS_BIN (parent)) {
3749 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3751 gst_object_unref (parent);
3759 compare_interface (GstElement * element, gpointer interface)
3761 GType interface_type = (GType) interface;
3764 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3767 /* we did not find the element, need to release the ref
3768 * added by the iterator */
3769 gst_object_unref (element);
3776 * gst_bin_get_by_interface:
3778 * @iface: the #GType of an interface
3780 * Looks for an element inside the bin that implements the given
3781 * interface. If such an element is found, it returns the element.
3782 * You can cast this element to the given interface afterwards. If you want
3783 * all elements that implement the interface, use
3784 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3786 * MT safe. Caller owns returned reference.
3788 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3791 gst_bin_get_by_interface (GstBin * bin, GType iface)
3793 GstIterator *children;
3796 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3797 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3799 children = gst_bin_iterate_recurse (bin);
3800 result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3802 gst_iterator_free (children);
3804 return GST_ELEMENT_CAST (result);
3808 * gst_bin_iterate_all_by_interface:
3810 * @iface: the #GType of an interface
3812 * Looks for all elements inside the bin that implements the given
3813 * interface. You can safely cast all returned elements to the given interface.
3814 * The function recurses inside child bins. The iterator will yield a series
3815 * of #GstElement that should be unreffed after use.
3817 * Each element yielded by the iterator will have its refcount increased, so
3820 * MT safe. Caller owns returned value.
3822 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3823 * in the bin implementing the given interface, or NULL
3826 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3828 GstIterator *children;
3829 GstIterator *result;
3831 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3832 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3834 children = gst_bin_iterate_recurse (bin);
3835 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3841 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
3843 gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
3845 GstBin *bin = GST_BIN_CAST (object);
3846 xmlNodePtr childlist, elementnode;
3850 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
3851 GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
3853 childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
3855 GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
3856 GST_ELEMENT_NAME (bin), bin->numchildren);
3858 children = g_list_last (bin->children);
3860 child = GST_ELEMENT_CAST (children->data);
3861 elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
3862 gst_object_save_thyself (GST_OBJECT (child), elementnode);
3863 children = g_list_previous (children);
3869 gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
3871 GstBin *bin = GST_BIN_CAST (object);
3872 xmlNodePtr field = self->xmlChildrenNode;
3873 xmlNodePtr childlist;
3876 if (!strcmp ((char *) field->name, "children")) {
3877 GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
3878 GST_ELEMENT_NAME (object));
3879 childlist = field->xmlChildrenNode;
3881 if (!strcmp ((char *) childlist->name, "element")) {
3882 /* gst_xml_make_element will gst_bin_add() the element to ourself */
3883 gst_xml_make_element (childlist, GST_OBJECT (bin));
3885 childlist = childlist->next;
3889 field = field->next;
3891 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
3892 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
3894 #endif /* GST_DISABLE_LOADSAVE */