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);
549 bin->priv = GST_BIN_GET_PRIVATE (bin);
550 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
551 bin->priv->structure_cookie = 0;
552 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
556 gst_bin_dispose (GObject * object)
558 GstBin *bin = GST_BIN_CAST (object);
559 GstBus **child_bus_p = &bin->child_bus;
560 GstClock **provided_clock_p = &bin->provided_clock;
561 GstElement **clock_provider_p = &bin->clock_provider;
562 GstIndex **index_p = &bin->priv->index;
564 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
566 GST_OBJECT_LOCK (object);
567 gst_object_replace ((GstObject **) child_bus_p, NULL);
568 gst_object_replace ((GstObject **) provided_clock_p, NULL);
569 gst_object_replace ((GstObject **) clock_provider_p, NULL);
570 gst_object_replace ((GstObject **) index_p, NULL);
571 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
572 GST_OBJECT_UNLOCK (object);
574 while (bin->children) {
575 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
577 if (G_UNLIKELY (bin->children != NULL)) {
578 g_critical ("could not remove elements from bin '%s'",
579 GST_STR_NULL (GST_OBJECT_NAME (object)));
582 G_OBJECT_CLASS (parent_class)->dispose (object);
587 * @name: the name of the new bin
589 * Creates a new bin with the given name.
591 * Returns: (transfer full): a new #GstBin
594 gst_bin_new (const gchar * name)
596 return gst_element_factory_make ("bin", name);
600 gst_bin_set_property (GObject * object, guint prop_id,
601 const GValue * value, GParamSpec * pspec)
605 gstbin = GST_BIN_CAST (object);
608 case PROP_ASYNC_HANDLING:
609 GST_OBJECT_LOCK (gstbin);
610 gstbin->priv->asynchandling = g_value_get_boolean (value);
611 GST_OBJECT_UNLOCK (gstbin);
613 case PROP_MESSAGE_FORWARD:
614 GST_OBJECT_LOCK (gstbin);
615 gstbin->priv->message_forward = g_value_get_boolean (value);
616 GST_OBJECT_UNLOCK (gstbin);
619 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
625 gst_bin_get_property (GObject * object, guint prop_id,
626 GValue * value, GParamSpec * pspec)
630 gstbin = GST_BIN_CAST (object);
633 case PROP_ASYNC_HANDLING:
634 GST_OBJECT_LOCK (gstbin);
635 g_value_set_boolean (value, gstbin->priv->asynchandling);
636 GST_OBJECT_UNLOCK (gstbin);
638 case PROP_MESSAGE_FORWARD:
639 GST_OBJECT_LOCK (gstbin);
640 g_value_set_boolean (value, gstbin->priv->message_forward);
641 GST_OBJECT_UNLOCK (gstbin);
644 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
649 /* return the cached index */
651 gst_bin_get_index_func (GstElement * element)
656 bin = GST_BIN_CAST (element);
658 GST_OBJECT_LOCK (bin);
659 if ((result = bin->priv->index))
660 gst_object_ref (result);
661 GST_OBJECT_UNLOCK (bin);
666 /* set the index on all elements in this bin
671 gst_bin_set_index_func (GstElement * element, GstIndex * index)
678 bin = GST_BIN_CAST (element);
680 GST_OBJECT_LOCK (bin);
681 old = bin->priv->index;
682 if (G_UNLIKELY (old == index))
685 gst_object_ref (index);
686 bin->priv->index = index;
687 GST_OBJECT_UNLOCK (bin);
690 gst_object_unref (old);
692 it = gst_bin_iterate_elements (bin);
694 /* set the index on all elements in the bin */
699 switch (gst_iterator_next (it, &data)) {
700 case GST_ITERATOR_OK:
702 GstElement *child = GST_ELEMENT_CAST (data);
704 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
705 GST_ELEMENT_NAME (child));
706 gst_element_set_index (child, index);
708 gst_object_unref (child);
711 case GST_ITERATOR_RESYNC:
712 GST_DEBUG_OBJECT (bin, "iterator doing resync");
713 gst_iterator_resync (it);
716 case GST_ITERATOR_DONE:
717 GST_DEBUG_OBJECT (bin, "iterator done");
722 gst_iterator_free (it);
727 GST_DEBUG_OBJECT (bin, "index was already set");
728 GST_OBJECT_UNLOCK (bin);
733 /* set the clock on all elements in this bin
738 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
745 bin = GST_BIN_CAST (element);
747 it = gst_bin_iterate_elements (bin);
753 switch (gst_iterator_next (it, &data)) {
754 case GST_ITERATOR_OK:
756 GstElement *child = GST_ELEMENT_CAST (data);
758 res &= gst_element_set_clock (child, clock);
760 gst_object_unref (child);
763 case GST_ITERATOR_RESYNC:
764 GST_DEBUG_OBJECT (bin, "iterator doing resync");
765 gst_iterator_resync (it);
769 case GST_ITERATOR_DONE:
770 GST_DEBUG_OBJECT (bin, "iterator done");
775 gst_iterator_free (it);
780 /* get the clock for this bin by asking all of the children in this bin
782 * The ref of the returned clock in increased so unref after usage.
784 * We loop the elements in state order and pick the last clock we can
785 * get. This makes sure we get a clock from the source.
790 gst_bin_provide_clock_func (GstElement * element)
792 GstClock *result = NULL;
793 GstElement *provider = NULL;
797 GstClock **provided_clock_p;
798 GstElement **clock_provider_p;
800 bin = GST_BIN_CAST (element);
802 GST_OBJECT_LOCK (bin);
803 if (!bin->clock_dirty)
806 GST_DEBUG_OBJECT (bin, "finding new clock");
808 it = gst_bin_sort_iterator_new (bin);
810 while (it->next (it, &val) == GST_ITERATOR_OK) {
811 GstElement *child = GST_ELEMENT_CAST (val);
814 clock = gst_element_provide_clock (child);
816 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
817 clock, GST_ELEMENT_NAME (child));
819 gst_object_unref (result);
820 gst_object_unref (provider);
825 gst_object_unref (child);
829 provided_clock_p = &bin->provided_clock;
830 clock_provider_p = &bin->clock_provider;
831 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
832 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
833 bin->clock_dirty = FALSE;
834 GST_DEBUG_OBJECT (bin,
835 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
837 /* Provider is not being returned to caller, just the result */
839 gst_object_unref (provider);
840 GST_OBJECT_UNLOCK (bin);
842 gst_iterator_free (it);
848 if ((result = bin->provided_clock))
849 gst_object_ref (result);
850 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
851 GST_OBJECT_UNLOCK (bin);
858 * functions for manipulating cached messages
863 GstMessageType types;
866 /* check if a message is of given src and type */
868 message_check (GstMessage * message, MessageFind * target)
873 eq &= GST_MESSAGE_SRC (message) == target->src;
875 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
876 GST_LOG ("looking at message %p: %d", message, eq);
882 find_message (GstBin * bin, GstObject * src, GstMessageType types)
890 result = g_list_find_custom (bin->messages, &find,
891 (GCompareFunc) message_check);
894 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
895 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
898 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
899 #ifndef GST_DISABLE_GST_DEBUG
903 for (i = 0; i < 32; i++)
904 if (types & (1 << i))
905 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
913 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
916 * A message that is cached and has the same SRC and type is replaced
917 * by the given message.
920 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
926 if ((src = GST_MESSAGE_SRC (message))) {
927 /* first find the previous message posted by this element */
928 if ((previous = find_message (bin, src, types))) {
929 GstMessage *previous_msg;
931 /* if we found a previous message, replace it */
932 previous_msg = previous->data;
933 previous->data = message;
935 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
936 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
937 GST_MESSAGE_TYPE_NAME (message));
939 gst_message_unref (previous_msg);
941 /* keep new message */
942 bin->messages = g_list_prepend (bin->messages, message);
944 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
945 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
948 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
949 GST_MESSAGE_TYPE_NAME (message));
951 gst_message_unref (message);
956 /* with LOCK. Remove all messages of given types */
958 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
966 for (walk = bin->messages; walk; walk = next) {
967 GstMessage *message = (GstMessage *) walk->data;
969 next = g_list_next (walk);
971 if (message_check (message, &find) == 0) {
972 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
973 "deleting message %p of types 0x%08x", message, types);
974 bin->messages = g_list_delete_link (bin->messages, walk);
975 gst_message_unref (message);
977 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
978 "not deleting message %p of type 0x%08x", message,
979 GST_MESSAGE_TYPE (message));
985 /* Check if the bin is EOS. We do this by scanning all sinks and
986 * checking if they posted an EOS message.
988 * call with bin LOCK */
990 is_eos (GstBin * bin)
996 for (walk = bin->children; walk; walk = g_list_next (walk)) {
999 element = GST_ELEMENT_CAST (walk->data);
1000 if (bin_element_is_sink (element, bin) == 0) {
1001 /* check if element posted EOS */
1002 if (find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS)) {
1003 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1005 GST_DEBUG ("sink '%s' did not post EOS yet",
1006 GST_ELEMENT_NAME (element));
1016 unlink_pads (GstPad * pad)
1020 if ((peer = gst_pad_get_peer (pad))) {
1021 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1022 gst_pad_unlink (pad, peer);
1024 gst_pad_unlink (peer, pad);
1025 gst_object_unref (peer);
1027 gst_object_unref (pad);
1030 /* vmethod that adds an element to a bin
1035 gst_bin_add_func (GstBin * bin, GstElement * element)
1039 gboolean is_sink, is_source;
1040 GstMessage *clock_message = NULL, *async_message = NULL;
1041 GstStateChangeReturn ret;
1043 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1045 /* we obviously can't add ourself to ourself */
1046 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1049 /* get the element name to make sure it is unique in this bin. */
1050 GST_OBJECT_LOCK (element);
1051 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1052 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1053 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1054 GST_OBJECT_UNLOCK (element);
1056 GST_OBJECT_LOCK (bin);
1058 /* then check to see if the element's name is already taken in the bin,
1059 * we can safely take the lock here. This check is probably bogus because
1060 * you can safely change the element name after this check and before setting
1061 * the object parent. The window is very small though... */
1062 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1063 goto duplicate_name;
1065 /* set the element's parent and add the element to the bin's list of children */
1066 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1067 GST_OBJECT_CAST (bin))))
1070 /* if we add a sink we become a sink */
1072 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1074 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1077 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1079 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1081 if (gst_element_provides_clock (element)) {
1082 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1084 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1087 bin->children = g_list_prepend (bin->children, element);
1089 bin->children_cookie++;
1090 bin->priv->structure_cookie++;
1092 /* distribute the bus */
1093 gst_element_set_bus (element, bin->child_bus);
1095 /* propagate the current base_time, start_time and clock */
1096 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1097 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1098 /* it's possible that the element did not accept the clock but
1099 * that is not important right now. When the pipeline goes to PLAYING,
1100 * a new clock will be selected */
1101 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1102 /* set the cached index on the children */
1103 if (bin->priv->index)
1104 gst_element_set_index (element, bin->priv->index);
1106 ret = GST_STATE_RETURN (bin);
1107 /* no need to update the state if we are in error */
1108 if (ret == GST_STATE_CHANGE_FAILURE)
1109 goto no_state_recalc;
1111 /* update the bin state, the new element could have been an ASYNC or
1112 * NO_PREROLL element */
1113 ret = GST_STATE_RETURN (element);
1114 GST_DEBUG_OBJECT (bin, "added %s element",
1115 gst_element_state_change_return_get_name (ret));
1118 case GST_STATE_CHANGE_ASYNC:
1120 /* create message to track this aync element when it posts an async-done
1123 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1126 case GST_STATE_CHANGE_NO_PREROLL:
1127 /* ignore all async elements we might have and commit our state */
1128 bin_handle_async_done (bin, ret, FALSE);
1130 case GST_STATE_CHANGE_FAILURE:
1137 GST_OBJECT_UNLOCK (bin);
1139 /* post the messages on the bus of the element so that the bin can handle
1142 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1145 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1147 /* unlink all linked pads */
1148 it = gst_element_iterate_pads (element);
1149 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1150 gst_iterator_free (it);
1152 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1156 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1157 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1161 /* ERROR handling here */
1164 GST_OBJECT_LOCK (bin);
1165 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1166 GST_OBJECT_UNLOCK (bin);
1171 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1172 elem_name, GST_ELEMENT_NAME (bin));
1173 GST_OBJECT_UNLOCK (bin);
1179 g_warning ("Element '%s' already has parent", elem_name);
1180 GST_OBJECT_UNLOCK (bin);
1189 * @element: (transfer full): the #GstElement to add
1191 * Adds the given element to the bin. Sets the element's parent, and thus
1192 * takes ownership of the element. An element can only be added to one bin.
1194 * If the element's pads are linked to other pads, the pads will be unlinked
1195 * before the element is added to the bin.
1198 * When you add an element to an already-running pipeline, you will have to
1199 * take care to set the state of the newly-added element to the desired
1200 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1201 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1202 * The bin or pipeline will not take care of this for you.
1207 * Returns: TRUE if the element could be added, FALSE if
1208 * the bin does not want to accept the element.
1211 gst_bin_add (GstBin * bin, GstElement * element)
1213 GstBinClass *bclass;
1216 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1217 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1219 bclass = GST_BIN_GET_CLASS (bin);
1221 if (G_UNLIKELY (bclass->add_element == NULL))
1224 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1225 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1226 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1228 result = bclass->add_element (bin, element);
1232 /* ERROR handling */
1235 g_warning ("adding elements to bin '%s' is not supported",
1236 GST_ELEMENT_NAME (bin));
1241 /* remove an element from the bin
1246 gst_bin_remove_func (GstBin * bin, GstElement * element)
1250 gboolean is_sink, is_source, othersink, othersource, found;
1251 GstMessage *clock_message = NULL;
1252 GstClock **provided_clock_p;
1253 GstElement **clock_provider_p;
1255 gboolean other_async, this_async, have_no_preroll;
1256 GstStateChangeReturn ret;
1258 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1260 GST_OBJECT_LOCK (element);
1261 /* Check if the element is already being removed and immediately
1263 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1264 goto already_removing;
1266 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1267 /* grab element name so we can print it */
1268 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1269 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1270 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1271 GST_OBJECT_UNLOCK (element);
1273 /* unlink all linked pads */
1274 it = gst_element_iterate_pads (element);
1275 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1276 gst_iterator_free (it);
1278 GST_OBJECT_LOCK (bin);
1281 othersource = FALSE;
1282 have_no_preroll = FALSE;
1283 /* iterate the elements, we collect which ones are async and no_preroll. We
1284 * also remove the element when we find it. */
1285 for (walk = bin->children; walk; walk = next) {
1286 GstElement *child = GST_ELEMENT_CAST (walk->data);
1288 next = g_list_next (walk);
1290 if (child == element) {
1292 /* remove the element */
1293 bin->children = g_list_delete_link (bin->children, walk);
1295 gboolean child_sink, child_source;
1297 GST_OBJECT_LOCK (child);
1298 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1299 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1300 /* when we remove a sink, check if there are other sinks. */
1301 if (is_sink && !othersink && child_sink)
1303 if (is_source && !othersource && child_source)
1305 /* check if we have NO_PREROLL children */
1306 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1307 have_no_preroll = TRUE;
1308 GST_OBJECT_UNLOCK (child);
1312 /* the element must have been in the bin's list of children */
1313 if (G_UNLIKELY (!found))
1316 /* we now removed the element from the list of elements, increment the cookie
1317 * so that others can detect a change in the children list. */
1319 bin->children_cookie++;
1320 bin->priv->structure_cookie++;
1322 if (is_sink && !othersink) {
1323 /* we're not a sink anymore */
1324 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1325 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1327 if (is_source && !othersource) {
1328 /* we're not a source anymore */
1329 GST_DEBUG_OBJECT (bin, "we removed the last source");
1330 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1334 /* if the clock provider for this element is removed, we lost
1335 * the clock as well, we need to inform the parent of this
1336 * so that it can select a new clock */
1337 if (bin->clock_provider == element) {
1338 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1339 bin->clock_dirty = TRUE;
1341 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1342 provided_clock_p = &bin->provided_clock;
1343 clock_provider_p = &bin->clock_provider;
1344 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1345 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1348 /* remove messages for the element, if there was a pending ASYNC_START
1349 * message we must see if removing the element caused the bin to lose its
1352 other_async = FALSE;
1353 for (walk = bin->messages; walk; walk = next) {
1354 GstMessage *message = (GstMessage *) walk->data;
1355 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1358 next = g_list_next (walk);
1361 switch (GST_MESSAGE_TYPE (message)) {
1362 case GST_MESSAGE_ASYNC_START:
1368 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1370 case GST_MESSAGE_STRUCTURE_CHANGE:
1374 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1376 /* it's unlikely that this message is still in the list of messages
1377 * because this would mean that a link/unlink is busy in another thread
1378 * while we remove the element. We still have to remove the message
1379 * because we might not receive the done message anymore when the element
1380 * is removed from the bin. */
1381 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1382 if (owner == element)
1393 /* delete all message types */
1394 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1395 message, elem_name);
1396 bin->messages = g_list_delete_link (bin->messages, walk);
1397 gst_message_unref (message);
1401 /* get last return */
1402 ret = GST_STATE_RETURN (bin);
1404 /* no need to update the state if we are in error */
1405 if (ret == GST_STATE_CHANGE_FAILURE)
1406 goto no_state_recalc;
1408 if (!other_async && this_async) {
1409 /* all other elements were not async and we removed the async one,
1410 * handle the async-done case because we are not async anymore now. */
1411 GST_DEBUG_OBJECT (bin,
1412 "we removed the last async element, have no_preroll %d",
1415 /* the current state return of the bin depends on if there are no_preroll
1416 * elements in the pipeline or not */
1417 if (have_no_preroll)
1418 ret = GST_STATE_CHANGE_NO_PREROLL;
1420 ret = GST_STATE_CHANGE_SUCCESS;
1422 bin_handle_async_done (bin, ret, FALSE);
1424 GST_DEBUG_OBJECT (bin,
1425 "recalc state preroll: %d, other async: %d, this async %d",
1426 have_no_preroll, other_async, this_async);
1428 if (have_no_preroll) {
1429 ret = GST_STATE_CHANGE_NO_PREROLL;
1430 } else if (other_async) {
1431 /* there are other async elements and we were not doing an async state
1432 * change, change our pending state and go async */
1433 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1434 GST_STATE_NEXT (bin) = GST_STATE (bin);
1435 GST_STATE_PENDING (bin) = GST_STATE (bin);
1437 ret = GST_STATE_CHANGE_ASYNC;
1439 GST_STATE_RETURN (bin) = ret;
1442 GST_OBJECT_UNLOCK (bin);
1445 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1447 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1451 gst_element_set_bus (element, NULL);
1453 /* Clear the clock we provided to the element */
1454 gst_element_set_clock (element, NULL);
1456 /* we ref here because after the _unparent() the element can be disposed
1457 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1458 gst_object_ref (element);
1459 gst_object_unparent (GST_OBJECT_CAST (element));
1461 GST_OBJECT_LOCK (element);
1462 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1463 GST_OBJECT_UNLOCK (element);
1465 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1466 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1468 /* element is really out of our control now */
1469 gst_object_unref (element);
1473 /* ERROR handling */
1476 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1477 GST_ELEMENT_NAME (bin));
1478 GST_OBJECT_UNLOCK (bin);
1484 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1485 GST_OBJECT_UNLOCK (element);
1493 * @element: (transfer none): the #GstElement to remove
1495 * Removes the element from the bin, unparenting it as well.
1496 * Unparenting the element means that the element will be dereferenced,
1497 * so if the bin holds the only reference to the element, the element
1498 * will be freed in the process of removing it from the bin. If you
1499 * want the element to still exist after removing, you need to call
1500 * gst_object_ref() before removing it from the bin.
1502 * If the element's pads are linked to other pads, the pads will be unlinked
1503 * before the element is removed from the bin.
1507 * Returns: TRUE if the element could be removed, FALSE if
1508 * the bin does not want to remove the element.
1511 gst_bin_remove (GstBin * bin, GstElement * element)
1513 GstBinClass *bclass;
1516 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1517 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1519 bclass = GST_BIN_GET_CLASS (bin);
1521 if (G_UNLIKELY (bclass->remove_element == NULL))
1524 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1525 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1527 result = bclass->remove_element (bin, element);
1531 /* ERROR handling */
1534 g_warning ("removing elements from bin '%s' is not supported",
1535 GST_ELEMENT_NAME (bin));
1540 static GstIteratorItem
1541 iterate_child (GstIterator * it, GstElement * child)
1543 gst_object_ref (child);
1544 return GST_ITERATOR_ITEM_PASS;
1548 * gst_bin_iterate_elements:
1551 * Gets an iterator for the elements in this bin.
1553 * Each element yielded by the iterator will have its refcount increased, so
1556 * MT safe. Caller owns returned value.
1558 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1561 gst_bin_iterate_elements (GstBin * bin)
1563 GstIterator *result;
1565 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1567 GST_OBJECT_LOCK (bin);
1568 /* add ref because the iterator refs the bin. When the iterator
1569 * is freed it will unref the bin again using the provided dispose
1571 gst_object_ref (bin);
1572 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1573 GST_OBJECT_GET_LOCK (bin),
1574 &bin->children_cookie,
1577 (GstIteratorItemFunction) iterate_child,
1578 (GstIteratorDisposeFunction) gst_object_unref);
1579 GST_OBJECT_UNLOCK (bin);
1584 static GstIteratorItem
1585 iterate_child_recurse (GstIterator * it, GstElement * child)
1587 gst_object_ref (child);
1588 if (GST_IS_BIN (child)) {
1589 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1591 gst_iterator_push (it, other);
1593 return GST_ITERATOR_ITEM_PASS;
1597 * gst_bin_iterate_recurse:
1600 * Gets an iterator for the elements in this bin.
1601 * This iterator recurses into GstBin children.
1603 * Each element yielded by the iterator will have its refcount increased, so
1606 * MT safe. Caller owns returned value.
1608 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1611 gst_bin_iterate_recurse (GstBin * bin)
1613 GstIterator *result;
1615 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1617 GST_OBJECT_LOCK (bin);
1618 /* add ref because the iterator refs the bin. When the iterator
1619 * is freed it will unref the bin again using the provided dispose
1621 gst_object_ref (bin);
1622 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1623 GST_OBJECT_GET_LOCK (bin),
1624 &bin->children_cookie,
1627 (GstIteratorItemFunction) iterate_child_recurse,
1628 (GstIteratorDisposeFunction) gst_object_unref);
1629 GST_OBJECT_UNLOCK (bin);
1634 /* returns 0 when TRUE because this is a GCompareFunc */
1637 bin_element_is_sink (GstElement * child, GstBin * bin)
1641 /* we lock the child here for the remainder of the function to
1642 * get its name and flag safely. */
1643 GST_OBJECT_LOCK (child);
1644 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1646 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1647 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1649 GST_OBJECT_UNLOCK (child);
1650 return is_sink ? 0 : 1;
1654 sink_iterator_filter (GstElement * child, GstBin * bin)
1656 if (bin_element_is_sink (child, bin) == 0) {
1657 /* returns 0 because this is a GCompareFunc */
1660 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1662 gst_object_unref (child);
1668 * gst_bin_iterate_sinks:
1671 * Gets an iterator for all elements in the bin that have the
1672 * #GST_ELEMENT_IS_SINK flag set.
1674 * Each element yielded by the iterator will have its refcount increased, so
1677 * MT safe. Caller owns returned value.
1679 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1682 gst_bin_iterate_sinks (GstBin * bin)
1684 GstIterator *children;
1685 GstIterator *result;
1687 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1689 children = gst_bin_iterate_elements (bin);
1690 result = gst_iterator_filter (children,
1691 (GCompareFunc) sink_iterator_filter, bin);
1696 /* returns 0 when TRUE because this is a GCompareFunc */
1699 bin_element_is_src (GstElement * child, GstBin * bin)
1703 /* we lock the child here for the remainder of the function to
1704 * get its name and other info safely. */
1705 GST_OBJECT_LOCK (child);
1706 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1708 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1709 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1711 GST_OBJECT_UNLOCK (child);
1712 return is_src ? 0 : 1;
1716 src_iterator_filter (GstElement * child, GstBin * bin)
1718 if (bin_element_is_src (child, bin) == 0) {
1719 /* returns 0 because this is a GCompareFunc */
1722 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1724 gst_object_unref (child);
1730 * gst_bin_iterate_sources:
1733 * Gets an iterator for all elements in the bin that have the
1734 * #GST_ELEMENT_IS_SOURCE flag set.
1736 * Each element yielded by the iterator will have its refcount increased, so
1739 * MT safe. Caller owns returned value.
1741 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1744 gst_bin_iterate_sources (GstBin * bin)
1746 GstIterator *children;
1747 GstIterator *result;
1749 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1751 children = gst_bin_iterate_elements (bin);
1752 result = gst_iterator_filter (children,
1753 (GCompareFunc) src_iterator_filter, bin);
1761 static GstStateChangeReturn
1762 gst_bin_get_state_func (GstElement * element, GstState * state,
1763 GstState * pending, GstClockTime timeout)
1765 GstStateChangeReturn ret;
1767 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1769 ret = parent_class->get_state (element, state, pending, timeout);
1774 /***********************************************
1775 * Topologically sorted iterator
1776 * see http://en.wikipedia.org/wiki/Topological_sorting
1778 * For each element in the graph, an entry is kept in a HashTable
1779 * with its number of srcpad connections (degree).
1780 * We then change state of all elements without dependencies
1781 * (degree 0) and decrement the degree of all elements connected
1782 * on the sinkpads. When an element reaches degree 0, its state is
1784 * When all elements are handled the algorithm stops.
1786 typedef struct _GstBinSortIterator
1789 GQueue *queue; /* elements queued for state change */
1790 GstBin *bin; /* bin we iterate */
1791 gint mode; /* adding or removing dependency */
1792 GstElement *best; /* next element with least dependencies */
1793 gint best_deg; /* best degree */
1794 GHashTable *hash; /* hashtable with element dependencies */
1795 gboolean dirty; /* we detected structure change */
1796 } GstBinSortIterator;
1798 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1799 #define HASH_SET_DEGREE(bit, elem, deg) \
1800 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1801 #define HASH_GET_DEGREE(bit, elem) \
1802 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1804 /* add element to queue of next elements in the iterator.
1805 * We push at the tail to give higher priority elements a
1808 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1810 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1811 GST_ELEMENT_NAME (element));
1812 gst_object_ref (element);
1813 g_queue_push_tail (bit->queue, element);
1814 HASH_SET_DEGREE (bit, element, -1);
1818 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1822 if ((find = g_queue_find (bit->queue, element))) {
1823 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1824 GST_ELEMENT_NAME (element));
1826 g_queue_delete_link (bit->queue, find);
1827 gst_object_unref (element);
1829 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1830 GST_ELEMENT_NAME (element));
1834 /* clear the queue, unref all objects as we took a ref when
1835 * we added them to the queue */
1837 clear_queue (GQueue * queue)
1841 while ((p = g_queue_pop_head (queue)))
1842 gst_object_unref (p);
1845 /* set all degrees to 0. Elements marked as a sink are
1846 * added to the queue immediatly. Since we only look at the SINK flag of the
1847 * element, it is possible that we add non-sinks to the queue. These will be
1848 * removed from the queue again when we can prove that it provides data for some
1851 reset_degree (GstElement * element, GstBinSortIterator * bit)
1855 /* sinks are added right away */
1856 GST_OBJECT_LOCK (element);
1857 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1858 GST_OBJECT_UNLOCK (element);
1861 add_to_queue (bit, element);
1863 /* others are marked with 0 and handled when sinks are done */
1864 HASH_SET_DEGREE (bit, element, 0);
1868 /* adjust the degree of all elements connected to the given
1869 * element. If a degree of an element drops to 0, it is
1870 * added to the queue of elements to schedule next.
1872 * We have to make sure not to cross the bin boundary this element
1876 update_degree (GstElement * element, GstBinSortIterator * bit)
1878 gboolean linked = FALSE;
1880 GST_OBJECT_LOCK (element);
1881 /* don't touch degree if element has no sinkpads */
1882 if (element->numsinkpads != 0) {
1883 /* loop over all sinkpads, decrement degree for all connected
1884 * elements in this bin */
1887 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1890 pad = GST_PAD_CAST (pads->data);
1892 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1893 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1894 GST_MESSAGE_STRUCTURE_CHANGE))) {
1895 /* mark the iterator as dirty because we won't be updating the degree
1896 * of the peer parent now. This would result in the 'loop detected'
1897 * later on because the peer parent element could become the best next
1898 * element with a degree > 0. We will simply continue our state
1899 * changes and we'll eventually resync when the unlink completed and
1900 * the iterator cookie is updated. */
1905 if ((peer = gst_pad_get_peer (pad))) {
1906 GstElement *peer_element;
1908 if ((peer_element = gst_pad_get_parent_element (peer))) {
1909 GST_OBJECT_LOCK (peer_element);
1910 /* check that we don't go outside of this bin */
1911 if (GST_OBJECT_CAST (peer_element)->parent ==
1912 GST_OBJECT_CAST (bit->bin)) {
1913 gint old_deg, new_deg;
1915 old_deg = HASH_GET_DEGREE (bit, peer_element);
1917 /* check to see if we added an element as sink that was not really a
1918 * sink because it was connected to some other element. */
1919 if (old_deg == -1) {
1920 remove_from_queue (bit, peer_element);
1923 new_deg = old_deg + bit->mode;
1925 GST_DEBUG_OBJECT (bit->bin,
1926 "change element %s, degree %d->%d, linked to %s",
1927 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1928 GST_ELEMENT_NAME (element));
1930 /* update degree, it is possible that an element was in 0 and
1931 * reaches -1 here. This would mean that the element had no sinkpads
1932 * but became linked while the state change was happening. We will
1933 * resync on this with the structure change message. */
1935 /* degree hit 0, add to queue */
1936 add_to_queue (bit, peer_element);
1938 HASH_SET_DEGREE (bit, peer_element, new_deg);
1942 GST_OBJECT_UNLOCK (peer_element);
1943 gst_object_unref (peer_element);
1945 gst_object_unref (peer);
1950 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1951 GST_ELEMENT_NAME (element));
1953 GST_OBJECT_UNLOCK (element);
1956 /* find the next best element not handled yet. This is the one
1957 * with the lowest non-negative degree */
1959 find_element (GstElement * element, GstBinSortIterator * bit)
1963 /* element is already handled */
1964 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1967 /* first element or element with smaller degree */
1968 if (bit->best == NULL || bit->best_deg > degree) {
1969 bit->best = element;
1970 bit->best_deg = degree;
1974 /* get next element in iterator. the returned element has the
1975 * refcount increased */
1976 static GstIteratorResult
1977 gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
1979 GstBin *bin = bit->bin;
1981 /* empty queue, we have to find a next best element */
1982 if (g_queue_is_empty (bit->queue)) {
1986 bit->best_deg = G_MAXINT;
1987 g_list_foreach (bin->children, (GFunc) find_element, bit);
1988 if ((best = bit->best)) {
1989 /* when we detected an unlink, don't warn because our degrees might be
1990 * screwed up. We will resync later */
1991 if (bit->best_deg != 0 && !bit->dirty) {
1992 /* we don't fail on this one yet */
1993 GST_WARNING_OBJECT (bin, "loop dected in graph");
1994 g_warning ("loop detected in the graph of bin '%s'!!",
1995 GST_ELEMENT_NAME (bin));
1997 /* best unhandled element, schedule as next element */
1998 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
1999 GST_ELEMENT_NAME (best));
2000 gst_object_ref (best);
2001 HASH_SET_DEGREE (bit, best, -1);
2004 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2005 /* no more unhandled elements, we are done */
2006 return GST_ITERATOR_DONE;
2009 /* everything added to the queue got reffed */
2010 *result = g_queue_pop_head (bit->queue);
2013 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
2014 /* update degrees of linked elements */
2015 update_degree (GST_ELEMENT_CAST (*result), bit);
2017 return GST_ITERATOR_OK;
2020 /* clear queues, recalculate the degrees and restart. */
2022 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2024 GstBin *bin = bit->bin;
2026 GST_DEBUG_OBJECT (bin, "resync");
2028 clear_queue (bit->queue);
2030 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2031 /* calc degrees, incrementing */
2033 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2034 /* for the rest of the function we decrement the degrees */
2038 /* clear queues, unref bin and free iterator. */
2040 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2042 GstBin *bin = bit->bin;
2044 GST_DEBUG_OBJECT (bin, "free");
2045 clear_queue (bit->queue);
2046 g_queue_free (bit->queue);
2047 g_hash_table_destroy (bit->hash);
2048 gst_object_unref (bin);
2052 /* should be called with the bin LOCK held */
2053 static GstIterator *
2054 gst_bin_sort_iterator_new (GstBin * bin)
2056 GstBinSortIterator *result;
2058 /* we don't need an ItemFunction because we ref the items in the _next
2060 result = (GstBinSortIterator *)
2061 gst_iterator_new (sizeof (GstBinSortIterator),
2063 GST_OBJECT_GET_LOCK (bin),
2064 &bin->priv->structure_cookie,
2065 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2066 (GstIteratorItemFunction) NULL,
2067 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2068 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2069 result->queue = g_queue_new ();
2070 result->hash = g_hash_table_new (NULL, NULL);
2071 gst_object_ref (bin);
2073 gst_bin_sort_iterator_resync (result);
2075 return (GstIterator *) result;
2079 * gst_bin_iterate_sorted:
2082 * Gets an iterator for the elements in this bin in topologically
2083 * sorted order. This means that the elements are returned from
2084 * the most downstream elements (sinks) to the sources.
2086 * This function is used internally to perform the state changes
2087 * of the bin elements and for clock selection.
2089 * Each element yielded by the iterator will have its refcount increased, so
2092 * MT safe. Caller owns returned value.
2094 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2097 gst_bin_iterate_sorted (GstBin * bin)
2099 GstIterator *result;
2101 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2103 GST_OBJECT_LOCK (bin);
2104 result = gst_bin_sort_iterator_new (bin);
2105 GST_OBJECT_UNLOCK (bin);
2110 static GstStateChangeReturn
2111 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2112 GstClockTime base_time, GstClockTime start_time, GstState current,
2115 GstStateChangeReturn ret;
2116 GstState pending, child_current, child_pending;
2120 GST_STATE_LOCK (element);
2122 GST_OBJECT_LOCK (element);
2123 /* set base_time and start time on child */
2124 GST_ELEMENT_START_TIME (element) = start_time;
2125 element->base_time = base_time;
2126 /* peel off the locked flag */
2127 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2128 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2129 ret = GST_STATE_RETURN (element);
2130 child_current = GST_STATE (element);
2131 child_pending = GST_STATE_PENDING (element);
2132 GST_OBJECT_UNLOCK (element);
2134 /* skip locked elements */
2135 if (G_UNLIKELY (locked))
2138 /* if the element was no preroll, just start changing the state regardless
2139 * if it had async elements (in the case of a bin) because they won't preroll
2141 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2142 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2146 GST_OBJECT_LOCK (bin);
2147 pending = GST_STATE_PENDING (bin);
2149 /* Try not to change the state of elements that are already in the state we're
2151 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2152 (child_pending == GST_STATE_VOID_PENDING &&
2153 ((pending > child_current && next > child_current) ||
2154 (pending < child_current && next < child_current)))))
2157 /* the element was busy with an upwards async state change, we must wait for
2158 * an ASYNC_DONE message before we attemp to change the state. */
2160 find_message (bin, GST_OBJECT_CAST (element),
2161 GST_MESSAGE_ASYNC_START))) {
2162 #ifndef GST_DISABLE_GST_DEBUG
2163 GstMessage *message = GST_MESSAGE_CAST (found->data);
2165 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2166 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2168 /* only wait for upward state changes */
2169 if (next > current) {
2170 /* We found an async element check if we can force its state to change or
2171 * if we have to wait for it to preroll. */
2172 if (G_UNLIKELY (!enable_latency)) {
2173 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2174 "\tto preroll in order to perform correct latency calculations.\n"
2175 "\tPlease verify that the application continues to work correctly by\n"
2176 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2177 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2184 GST_OBJECT_UNLOCK (bin);
2187 GST_DEBUG_OBJECT (bin,
2188 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2189 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2190 GST_TIME_ARGS (base_time));
2193 ret = gst_element_set_state (element, next);
2195 GST_STATE_UNLOCK (element);
2201 GST_DEBUG_OBJECT (element,
2202 "element is locked, return previous return %s",
2203 gst_element_state_change_return_get_name (ret));
2204 GST_STATE_UNLOCK (element);
2209 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2210 GST_OBJECT_UNLOCK (bin);
2211 GST_STATE_UNLOCK (element);
2212 return GST_STATE_CHANGE_ASYNC;
2216 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2217 "skipping transition from %s to %s, since bin pending"
2218 " is %s : last change state return follows",
2219 gst_element_state_get_name (child_current),
2220 gst_element_state_get_name (next),
2221 gst_element_state_get_name (pending));
2222 GST_OBJECT_UNLOCK (bin);
2223 GST_STATE_UNLOCK (element);
2228 /* gst_iterator_fold functions for pads_activate
2229 * Note how we don't stop the iterator when we fail an activation. This is
2230 * probably a FIXME since when one pad activation fails, we don't want to
2231 * continue our state change. */
2233 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2235 if (!gst_pad_set_active (pad, *active))
2236 g_value_set_boolean (ret, FALSE);
2238 gst_pad_set_caps (pad, NULL);
2240 /* unref the object that was reffed for us by _fold */
2241 gst_object_unref (pad);
2245 /* returns false on error or early cutout (will never happen because the fold
2246 * function always returns TRUE, see FIXME above) of the fold, true if all
2247 * pads in @iter were (de)activated successfully. */
2249 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2251 GstIteratorResult ires;
2254 /* no need to unset this later, it's just a boolean */
2255 g_value_init (&ret, G_TYPE_BOOLEAN);
2256 g_value_set_boolean (&ret, TRUE);
2259 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2262 case GST_ITERATOR_RESYNC:
2263 /* need to reset the result again */
2264 g_value_set_boolean (&ret, TRUE);
2265 gst_iterator_resync (iter);
2267 case GST_ITERATOR_DONE:
2268 /* all pads iterated, return collected value */
2271 /* iterator returned _ERROR or premature end with _OK,
2272 * mark an error and exit */
2273 g_value_set_boolean (&ret, FALSE);
2278 /* return collected value */
2279 return g_value_get_boolean (&ret);
2282 /* is called with STATE_LOCK
2285 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2290 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2292 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2293 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2294 gst_iterator_free (iter);
2295 if (G_UNLIKELY (!fold_ok))
2298 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2305 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2311 * gst_bin_recalculate_latency:
2314 * Query @bin for the current latency using and reconfigures this latency to all the
2315 * elements with a LATENCY event.
2317 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2318 * is posted on the bus.
2320 * This function simply emits the 'do-latency' signal so any custom latency
2321 * calculations will be performed.
2323 * Returns: %TRUE if the latency could be queried and reconfigured.
2328 gst_bin_recalculate_latency (GstBin * bin)
2332 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2333 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2339 gst_bin_do_latency_func (GstBin * bin)
2342 GstElement *element;
2343 GstClockTime min_latency, max_latency;
2346 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2348 element = GST_ELEMENT_CAST (bin);
2350 GST_DEBUG_OBJECT (element, "querying latency");
2352 query = gst_query_new_latency ();
2353 if ((res = gst_element_query (element, query))) {
2356 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2358 GST_DEBUG_OBJECT (element,
2359 "got min latency %" GST_TIME_FORMAT ", max latency %"
2360 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2361 GST_TIME_ARGS (max_latency), live);
2363 if (max_latency < min_latency) {
2364 /* this is an impossible situation, some parts of the pipeline might not
2365 * work correctly. We post a warning for now. */
2366 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2367 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2368 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2369 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2372 /* configure latency on elements */
2373 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2375 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2376 GST_TIME_ARGS (min_latency));
2378 GST_WARNING_OBJECT (element,
2379 "did not really configure latency of %" GST_TIME_FORMAT,
2380 GST_TIME_ARGS (min_latency));
2383 /* this is not a real problem, we just don't configure any latency. */
2384 GST_WARNING_OBJECT (element, "failed to query latency");
2386 gst_query_unref (query);
2391 static GstStateChangeReturn
2392 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2395 GstStateChangeReturn ret;
2396 GstState current, next;
2397 gboolean have_async;
2398 gboolean have_no_preroll;
2399 GstClockTime base_time, start_time;
2403 /* we don't need to take the STATE_LOCK, it is already taken */
2404 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2405 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2407 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2408 "changing state of children from %s to %s",
2409 gst_element_state_get_name (current), gst_element_state_get_name (next));
2411 bin = GST_BIN_CAST (element);
2414 case GST_STATE_PLAYING:
2418 GST_OBJECT_LOCK (bin);
2419 toplevel = BIN_IS_TOPLEVEL (bin);
2420 GST_OBJECT_UNLOCK (bin);
2423 gst_bin_recalculate_latency (bin);
2426 case GST_STATE_PAUSED:
2427 /* Clear EOS list on next PAUSED */
2428 GST_OBJECT_LOCK (bin);
2429 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2430 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2431 GST_OBJECT_UNLOCK (bin);
2432 if (current == GST_STATE_READY)
2433 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2434 goto activate_failure;
2436 case GST_STATE_READY:
2437 /* Clear message list on next READY */
2438 GST_OBJECT_LOCK (bin);
2439 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2440 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2441 GST_OBJECT_UNLOCK (bin);
2442 if (current == GST_STATE_PAUSED)
2443 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2444 goto activate_failure;
2446 case GST_STATE_NULL:
2447 if (current == GST_STATE_READY)
2448 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2449 goto activate_failure;
2455 /* this flag is used to make the async state changes return immediatly. We
2456 * don't want them to interfere with this state change */
2457 GST_OBJECT_LOCK (bin);
2458 bin->polling = TRUE;
2459 GST_OBJECT_UNLOCK (bin);
2461 /* iterate in state change order */
2462 it = gst_bin_iterate_sorted (bin);
2464 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2465 * Note how we don't reset this value when a resync happens, the reason being
2466 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2467 * even after a resync when the async element is gone */
2471 /* take base_time */
2472 base_time = gst_element_get_base_time (element);
2473 start_time = gst_element_get_start_time (element);
2475 have_no_preroll = FALSE;
2481 switch (gst_iterator_next (it, &data)) {
2482 case GST_ITERATOR_OK:
2486 child = GST_ELEMENT_CAST (data);
2488 /* set state and base_time now */
2489 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2493 case GST_STATE_CHANGE_SUCCESS:
2494 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2495 "child '%s' changed state to %d(%s) successfully",
2496 GST_ELEMENT_NAME (child), next,
2497 gst_element_state_get_name (next));
2499 case GST_STATE_CHANGE_ASYNC:
2501 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2502 "child '%s' is changing state asynchronously to %s",
2503 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2507 case GST_STATE_CHANGE_FAILURE:{
2510 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2511 "child '%s' failed to go to state %d(%s)",
2512 GST_ELEMENT_NAME (child),
2513 next, gst_element_state_get_name (next));
2515 /* Only fail if the child is still inside
2516 * this bin. It might've been removed already
2517 * because of the error by the bin subclass
2518 * to ignore the error. */
2519 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2520 if (parent == GST_OBJECT_CAST (element)) {
2521 /* element is still in bin, really error now */
2522 gst_object_unref (child);
2523 gst_object_unref (parent);
2526 /* child removed from bin, let the resync code redo the state
2528 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2529 "child '%s' was removed from the bin",
2530 GST_ELEMENT_NAME (child));
2533 gst_object_unref (parent);
2537 case GST_STATE_CHANGE_NO_PREROLL:
2538 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2539 "child '%s' changed state to %d(%s) successfully without preroll",
2540 GST_ELEMENT_NAME (child), next,
2541 gst_element_state_get_name (next));
2542 have_no_preroll = TRUE;
2545 g_assert_not_reached ();
2548 gst_object_unref (child);
2551 case GST_ITERATOR_RESYNC:
2552 GST_CAT_DEBUG (GST_CAT_STATES, "iterator doing resync");
2553 gst_iterator_resync (it);
2556 case GST_ITERATOR_DONE:
2557 GST_CAT_DEBUG (GST_CAT_STATES, "iterator done");
2563 ret = parent_class->change_state (element, transition);
2564 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2567 if (have_no_preroll) {
2568 GST_CAT_DEBUG (GST_CAT_STATES,
2569 "we have NO_PREROLL elements %s -> NO_PREROLL",
2570 gst_element_state_change_return_get_name (ret));
2571 ret = GST_STATE_CHANGE_NO_PREROLL;
2572 } else if (have_async) {
2573 GST_CAT_DEBUG (GST_CAT_STATES, "we have ASYNC elements %s -> ASYNC",
2574 gst_element_state_change_return_get_name (ret));
2575 ret = GST_STATE_CHANGE_ASYNC;
2579 gst_iterator_free (it);
2581 GST_OBJECT_LOCK (bin);
2582 bin->polling = FALSE;
2583 /* it's possible that we did not get ASYNC from the children while the bin is
2584 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2585 * itself as the source. In that case we still want to check if the state
2586 * change completed. */
2587 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2588 /* no element returned ASYNC and there are no pending async_done messages,
2589 * we can just complete. */
2590 GST_DEBUG_OBJECT (bin, "no async elements");
2593 /* when we get here an ASYNC element was found */
2594 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2595 /* we ignore ASYNC state changes when we go to READY or NULL */
2596 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2597 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2601 GST_DEBUG_OBJECT (bin, "check async elements");
2602 /* check if all elements managed to commit their state already */
2603 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2604 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2605 * all the elements commited their state while we were doing the state
2606 * change. We will still return ASYNC for consistency but we commit the
2607 * state already so that a _get_state() will return immediatly. */
2608 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2610 GST_DEBUG_OBJECT (bin, "async elements commited");
2611 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2615 bin->priv->pending_async_done = FALSE;
2616 GST_OBJECT_UNLOCK (bin);
2618 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2619 "done changing bin's state from %s to %s, now in %s, ret %s",
2620 gst_element_state_get_name (current),
2621 gst_element_state_get_name (next),
2622 gst_element_state_get_name (GST_STATE (element)),
2623 gst_element_state_change_return_get_name (ret));
2630 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2631 "failure (de)activating src pads");
2632 return GST_STATE_CHANGE_FAILURE;
2637 * This function is a utility event handler for seek events.
2638 * It will send the event to all sinks or sources depending on the
2641 * Applications are free to override this behaviour and
2642 * implement their own seek handler, but this will work for
2643 * pretty much all cases in practice.
2646 gst_bin_send_event (GstElement * element, GstEvent * event)
2648 GstBin *bin = GST_BIN_CAST (element);
2650 gboolean res = TRUE;
2651 gboolean done = FALSE;
2653 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2654 iter = gst_bin_iterate_sources (bin);
2655 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2656 GST_EVENT_TYPE_NAME (event));
2658 iter = gst_bin_iterate_sinks (bin);
2659 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2660 GST_EVENT_TYPE_NAME (event));
2666 switch (gst_iterator_next (iter, &data)) {
2667 case GST_ITERATOR_OK:
2671 gst_event_ref (event);
2672 child = GST_ELEMENT_CAST (data);
2673 res &= gst_element_send_event (child, event);
2674 gst_object_unref (child);
2677 case GST_ITERATOR_RESYNC:
2678 gst_iterator_resync (iter);
2681 case GST_ITERATOR_DONE:
2684 case GST_ITERATOR_ERROR:
2685 g_assert_not_reached ();
2689 gst_iterator_free (iter);
2690 gst_event_unref (event);
2695 /* this is the function called by the threadpool. When async elements commit
2696 * their state, this function will attempt to bring the bin to the next state.
2699 gst_bin_continue_func (BinContinueData * data)
2702 GstState current, next, pending;
2703 GstStateChange transition;
2706 pending = data->pending;
2708 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2709 GST_STATE_LOCK (bin);
2711 GST_DEBUG_OBJECT (bin, "doing state continue");
2712 GST_OBJECT_LOCK (bin);
2714 /* if a new state change happened after this thread was scheduled, we return
2716 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2719 current = GST_STATE (bin);
2720 next = GST_STATE_GET_NEXT (current, pending);
2721 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2723 GST_STATE_NEXT (bin) = next;
2724 GST_STATE_PENDING (bin) = pending;
2726 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2727 GST_OBJECT_UNLOCK (bin);
2729 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2730 "continue state change %s to %s, final %s",
2731 gst_element_state_get_name (current),
2732 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2734 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2736 GST_STATE_UNLOCK (bin);
2737 GST_DEBUG_OBJECT (bin, "state continue done");
2738 gst_object_unref (bin);
2739 g_slice_free (BinContinueData, data);
2744 GST_OBJECT_UNLOCK (bin);
2745 GST_STATE_UNLOCK (bin);
2746 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2747 gst_object_unref (bin);
2748 g_slice_free (BinContinueData, data);
2753 static GstBusSyncReply
2754 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2756 GstBinClass *bclass;
2758 bclass = GST_BIN_GET_CLASS (bin);
2759 if (bclass->handle_message)
2760 bclass->handle_message (bin, message);
2762 gst_message_unref (message);
2764 return GST_BUS_DROP;
2768 bin_push_state_continue (BinContinueData * data)
2775 klass = GST_BIN_GET_CLASS (bin);
2777 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2778 g_thread_pool_push (klass->pool, data, NULL);
2781 /* an element started an async state change, if we were not busy with a state
2782 * change, we perform a lost state.
2783 * This function is called with the OBJECT lock.
2786 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2788 GstState old_state, new_state;
2790 GstMessage *amessage = NULL;
2792 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2795 /* get our toplevel state */
2796 toplevel = BIN_IS_TOPLEVEL (bin);
2798 /* prepare an ASYNC_START message, we always post the start message even if we
2799 * are busy with a state change or when we are NO_PREROLL. */
2801 /* non toplevel bin, prepare async-start for the parent */
2803 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2805 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2808 /* async starts are ignored when we are NO_PREROLL */
2809 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2810 goto was_no_preroll;
2812 old_state = GST_STATE (bin);
2814 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2815 * PLAYING after optionally redistributing the base_time. */
2816 if (old_state > GST_STATE_PAUSED)
2817 new_state = GST_STATE_PAUSED;
2819 new_state = old_state;
2821 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2822 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2823 gst_element_state_get_name (new_state));
2825 GST_STATE (bin) = new_state;
2826 GST_STATE_NEXT (bin) = new_state;
2827 GST_STATE_PENDING (bin) = new_state;
2828 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2829 GST_OBJECT_UNLOCK (bin);
2832 gst_element_post_message (GST_ELEMENT_CAST (bin),
2833 gst_message_new_state_changed (GST_OBJECT_CAST (bin),
2834 new_state, new_state, new_state));
2838 /* post our ASYNC_START. */
2839 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2840 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2842 GST_OBJECT_LOCK (bin);
2848 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2853 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2854 GST_OBJECT_UNLOCK (bin);
2859 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2860 GST_OBJECT_UNLOCK (bin);
2865 /* this function is called when there are no more async elements in the bin. We
2866 * post a state changed message and an ASYNC_DONE message.
2867 * This function is called with the OBJECT lock.
2870 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2871 gboolean flag_pending)
2873 GstState current, pending, target;
2874 GstStateChangeReturn old_ret;
2875 GstState old_state, old_next;
2877 GstMessage *smessage = NULL, *amessage = NULL;
2878 BinContinueData *cont = NULL;
2880 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2883 pending = GST_STATE_PENDING (bin);
2888 /* check if there is something to commit */
2889 if (pending == GST_STATE_VOID_PENDING)
2890 goto nothing_pending;
2892 old_ret = GST_STATE_RETURN (bin);
2893 GST_STATE_RETURN (bin) = ret;
2895 /* move to the next target state */
2896 target = GST_STATE_TARGET (bin);
2897 pending = GST_STATE_PENDING (bin) = target;
2899 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2901 old_state = GST_STATE (bin);
2902 /* this is the state we should go to next */
2903 old_next = GST_STATE_NEXT (bin);
2905 if (old_next != GST_STATE_PLAYING) {
2906 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2907 "committing state from %s to %s, old pending %s",
2908 gst_element_state_get_name (old_state),
2909 gst_element_state_get_name (old_next),
2910 gst_element_state_get_name (pending));
2912 /* update current state */
2913 current = GST_STATE (bin) = old_next;
2915 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2916 "setting state from %s to %s, pending %s",
2917 gst_element_state_get_name (old_state),
2918 gst_element_state_get_name (old_state),
2919 gst_element_state_get_name (pending));
2920 current = old_state;
2923 /* get our toplevel state */
2924 toplevel = BIN_IS_TOPLEVEL (bin);
2926 /* see if we reached the final state. If we are not toplevel, we also have to
2927 * stop here, the parent will continue our state. */
2928 if ((pending == current) || !toplevel) {
2929 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2930 "completed state change, pending VOID");
2932 /* mark VOID pending */
2933 pending = GST_STATE_VOID_PENDING;
2934 GST_STATE_PENDING (bin) = pending;
2935 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2937 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2938 "continue state change, pending %s",
2939 gst_element_state_get_name (pending));
2941 cont = g_slice_new (BinContinueData);
2943 /* ref to the bin */
2944 cont->bin = gst_object_ref (bin);
2945 /* cookie to detect concurrent state change */
2946 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2947 /* pending target state */
2948 cont->pending = pending;
2950 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2951 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2954 if (old_next != GST_STATE_PLAYING) {
2955 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2956 smessage = gst_message_new_state_changed (GST_OBJECT_CAST (bin),
2957 old_state, old_next, pending);
2960 GST_OBJECT_UNLOCK (bin);
2963 GST_DEBUG_OBJECT (bin, "posting state change message");
2964 gst_element_post_message (GST_ELEMENT_CAST (bin), smessage);
2967 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2968 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
2969 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2972 GST_OBJECT_LOCK (bin);
2974 /* toplevel, start continue state */
2975 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
2976 bin_push_state_continue (cont);
2978 GST_DEBUG_OBJECT (bin, "state change complete");
2979 GST_STATE_BROADCAST (bin);
2985 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2990 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2991 /* if we were busy with a state change and we are requested to flag a
2992 * pending async done, we do so here */
2994 bin->priv->pending_async_done = TRUE;
2999 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3004 /* must be called with the object lock. This function releases the lock to post
3007 bin_do_message_forward (GstBin * bin, GstMessage * message)
3009 if (bin->priv->message_forward) {
3010 GstMessage *forwarded;
3012 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3013 GST_MESSAGE_TYPE_NAME (message));
3014 GST_OBJECT_UNLOCK (bin);
3016 /* we need to convert these messages to element messages so that our parent
3017 * bin can easily ignore them and so that the application can easily
3018 * distinguish between the internally forwarded and the real messages. */
3019 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3020 gst_structure_new ("GstBinForwarded",
3021 "message", GST_TYPE_MESSAGE, message, NULL));
3023 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3025 GST_OBJECT_LOCK (bin);
3029 /* handle child messages:
3031 * This method is called synchronously when a child posts a message on
3034 * GST_MESSAGE_EOS: This message is only posted by sinks
3035 * in the PLAYING state. If all sinks posted the EOS message, post
3038 * GST_MESSAGE_STATE_DIRTY: Deprecated
3040 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3041 * element posts segment_start twice, only the last message is kept.
3043 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3044 * with the segment_done message. If there are no more segment_start
3045 * messages, post segment_done message upwards.
3047 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3048 * Whenever someone performs a duration query on the bin, we store the
3049 * result so we can answer it quicker the next time. Any element that
3050 * changes its duration marks our cached values invalid.
3051 * This message is also posted upwards. This is currently disabled
3052 * because too many elements don't post DURATION messages when the
3055 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3056 * can no longer provide a clock. The default bin behaviour is to
3057 * check if the lost clock was the one provided by the bin. If so and
3058 * we are currently in the PLAYING state, we forward the message to
3060 * This message is also generated when we remove a clock provider from
3061 * a bin. If this message is received by the application, it should
3062 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3063 * and a new base_time distribution.
3065 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3066 * can provide a clock. This mostly happens when we add a new clock
3067 * provider to the bin. The default behaviour of the bin is to mark the
3068 * currently selected clock as dirty, which will perform a clock
3069 * recalculation the next time we are asked to provide a clock.
3070 * This message is never sent to the application but is forwarded to
3073 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3074 * the state of the element and the fact that the element will need a
3075 * new base_time. This message is not forwarded to the application.
3077 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3078 * element when it posted ASYNC_START. If all elements are done, post a
3079 * ASYNC_DONE message to the parent.
3081 * OTHER: post upwards.
3084 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3087 GstMessageType type;
3088 GstMessage *tmessage;
3091 src = GST_MESSAGE_SRC (message);
3092 type = GST_MESSAGE_TYPE (message);
3094 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3095 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3096 GST_MESSAGE_TYPE_NAME (message));
3099 case GST_MESSAGE_ERROR:
3101 GST_OBJECT_LOCK (bin);
3103 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3104 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3105 GST_STATE_BROADCAST (bin);
3106 GST_OBJECT_UNLOCK (bin);
3110 case GST_MESSAGE_EOS:
3114 /* collect all eos messages from the children */
3115 GST_OBJECT_LOCK (bin);
3116 bin_do_message_forward (bin, message);
3117 /* ref message for future use */
3118 gst_message_ref (message);
3119 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3121 GST_OBJECT_UNLOCK (bin);
3123 /* if we are completely EOS, we forward an EOS message */
3125 seqnum = gst_message_get_seqnum (message);
3126 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3127 gst_message_set_seqnum (tmessage, seqnum);
3129 GST_DEBUG_OBJECT (bin,
3130 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3131 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3133 gst_message_unref (message);
3136 case GST_MESSAGE_STATE_DIRTY:
3138 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3141 gst_message_unref (message);
3144 case GST_MESSAGE_SEGMENT_START:{
3145 gboolean post = FALSE;
3149 gst_message_parse_segment_start (message, &format, &position);
3150 seqnum = gst_message_get_seqnum (message);
3152 GST_OBJECT_LOCK (bin);
3153 bin_do_message_forward (bin, message);
3154 /* if this is the first segment-start, post to parent but not to the
3156 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3157 (GST_OBJECT_PARENT (bin) != NULL)) {
3160 /* replace any previous segment_start message from this source
3161 * with the new segment start message */
3162 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3163 GST_OBJECT_UNLOCK (bin);
3165 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3167 gst_message_set_seqnum (tmessage, seqnum);
3169 /* post segment start with initial format and position. */
3170 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3172 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3176 case GST_MESSAGE_SEGMENT_DONE:
3178 gboolean post = FALSE;
3182 gst_message_parse_segment_done (message, &format, &position);
3183 seqnum = gst_message_get_seqnum (message);
3185 GST_OBJECT_LOCK (bin);
3186 bin_do_message_forward (bin, message);
3187 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3188 /* if there are no more segment_start messages, everybody posted
3189 * a segment_done and we can post one on the bus. */
3191 /* we don't care who still has a pending segment start */
3192 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3195 /* remove all old segment_done messages */
3196 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3198 GST_OBJECT_UNLOCK (bin);
3200 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3202 gst_message_set_seqnum (tmessage, seqnum);
3204 /* post segment done with latest format and position. */
3205 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3207 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3211 case GST_MESSAGE_DURATION:
3213 /* remove all cached duration messages, next time somebody asks
3214 * for duration, we will recalculate. */
3215 GST_OBJECT_LOCK (bin);
3216 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3217 GST_OBJECT_UNLOCK (bin);
3220 case GST_MESSAGE_CLOCK_LOST:
3222 GstClock **provided_clock_p;
3223 GstElement **clock_provider_p;
3224 gboolean playing, provided, forward;
3227 gst_message_parse_clock_lost (message, &clock);
3229 GST_OBJECT_LOCK (bin);
3230 bin->clock_dirty = TRUE;
3231 /* if we lost the clock that we provided, post to parent but
3232 * only if we are PLAYING. */
3233 provided = (clock == bin->provided_clock);
3234 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3235 forward = playing & provided;
3237 GST_DEBUG_OBJECT (bin,
3238 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3239 bin->provided_clock, bin->clock_provider);
3240 provided_clock_p = &bin->provided_clock;
3241 clock_provider_p = &bin->clock_provider;
3242 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3243 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3245 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3246 provided, playing, forward);
3247 GST_OBJECT_UNLOCK (bin);
3253 gst_message_unref (message);
3256 case GST_MESSAGE_CLOCK_PROVIDE:
3260 GST_OBJECT_LOCK (bin);
3261 bin->clock_dirty = TRUE;
3262 /* a new clock is available, post to parent but not
3263 * to the application */
3264 forward = GST_OBJECT_PARENT (bin) != NULL;
3265 GST_OBJECT_UNLOCK (bin);
3271 gst_message_unref (message);
3274 case GST_MESSAGE_ASYNC_START:
3276 gboolean new_base_time;
3279 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3280 src ? GST_OBJECT_NAME (src) : "(NULL)");
3282 gst_message_parse_async_start (message, &new_base_time);
3284 GST_OBJECT_LOCK (bin);
3285 bin_do_message_forward (bin, message);
3287 /* we ignore the message if we are going to <= READY */
3288 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3289 goto ignore_start_message;
3291 /* takes ownership of the message */
3292 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3294 bin_handle_async_start (bin, new_base_time);
3295 GST_OBJECT_UNLOCK (bin);
3298 ignore_start_message:
3300 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3301 gst_element_state_get_name (target));
3302 GST_OBJECT_UNLOCK (bin);
3303 gst_message_unref (message);
3307 case GST_MESSAGE_ASYNC_DONE:
3311 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3312 src ? GST_OBJECT_NAME (src) : "(NULL)");
3314 GST_OBJECT_LOCK (bin);
3315 bin_do_message_forward (bin, message);
3317 /* ignore messages if we are shutting down */
3318 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3319 goto ignore_done_message;
3321 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3322 /* if there are no more ASYNC_START messages, everybody posted
3323 * a ASYNC_DONE and we can post one on the bus. When checking, we
3324 * don't care who still has a pending ASYNC_START */
3325 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3326 /* nothing found, remove all old ASYNC_DONE messages */
3327 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3329 GST_DEBUG_OBJECT (bin, "async elements commited");
3330 /* when we get an async done message when a state change was busy, we
3331 * need to set the pending_done flag so that at the end of the state
3332 * change we can see if we need to verify pending async elements, hence
3333 * the TRUE argument here. */
3334 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3336 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3338 GST_OBJECT_UNLOCK (bin);
3341 ignore_done_message:
3343 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3344 gst_element_state_get_name (target));
3345 GST_OBJECT_UNLOCK (bin);
3346 gst_message_unref (message);
3350 case GST_MESSAGE_STRUCTURE_CHANGE:
3354 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3356 GST_OBJECT_LOCK (bin);
3358 /* while the pad is busy, avoid following it when doing state changes.
3359 * Don't update the cookie yet, we will do that after the structure
3360 * change finished and we are ready to inspect the new updated
3362 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3365 /* a pad link/unlink ended, signal the state change iterator that we
3366 * need to resync by updating the structure_cookie. */
3367 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3368 GST_MESSAGE_STRUCTURE_CHANGE);
3369 bin->priv->structure_cookie++;
3371 GST_OBJECT_UNLOCK (bin);
3374 gst_message_unref (message);
3385 /* Send all other messages upward */
3386 GST_DEBUG_OBJECT (bin, "posting message upward");
3387 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3392 /* generic struct passed to all query fold methods */
3401 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3402 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3404 /* for duration/position we collect all durations/positions and take
3405 * the MAX of all valid results */
3407 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3415 bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
3417 if (gst_element_query (item, fold->query)) {
3420 g_value_set_boolean (ret, TRUE);
3422 gst_query_parse_duration (fold->query, NULL, &duration);
3424 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3426 if (duration > fold->max)
3427 fold->max = duration;
3430 gst_object_unref (item);
3435 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3439 gst_query_parse_duration (fold->query, &format, NULL);
3440 /* store max in query result */
3441 gst_query_set_duration (fold->query, format, fold->max);
3443 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3445 #ifdef DURATION_CACHING
3447 GST_OBJECT_LOCK (bin);
3448 bin->messages = g_list_prepend (bin->messages,
3449 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3450 GST_OBJECT_UNLOCK (bin);
3455 bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
3457 if (gst_element_query (item, fold->query)) {
3460 g_value_set_boolean (ret, TRUE);
3462 gst_query_parse_position (fold->query, NULL, &position);
3464 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3466 if (position > fold->max)
3467 fold->max = position;
3470 gst_object_unref (item);
3475 bin_query_position_done (GstBin * bin, QueryFold * fold)
3479 gst_query_parse_position (fold->query, &format, NULL);
3480 /* store max in query result */
3481 gst_query_set_position (fold->query, format, fold->max);
3483 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3487 bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
3489 if (gst_element_query (item, fold->query)) {
3490 GstClockTime min, max;
3493 gst_query_parse_latency (fold->query, &live, &min, &max);
3495 GST_DEBUG_OBJECT (item,
3496 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3497 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3499 /* for the combined latency we collect the MAX of all min latencies and
3500 * the MIN of all max latencies */
3502 if (min > fold->min)
3504 if (fold->max == -1)
3506 else if (max < fold->max)
3508 if (fold->live == FALSE)
3512 g_value_set_boolean (ret, FALSE);
3513 GST_DEBUG_OBJECT (item, "failed query");
3516 gst_object_unref (item);
3521 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3523 /* store max in query result */
3524 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3526 GST_DEBUG_OBJECT (bin,
3527 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3528 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3532 /* generic fold, return first valid result */
3534 bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
3538 if ((res = gst_element_query (item, fold->query))) {
3539 g_value_set_boolean (ret, TRUE);
3540 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3543 gst_object_unref (item);
3545 /* and stop as soon as we have a valid result */
3550 gst_bin_query (GstElement * element, GstQuery * query)
3552 GstBin *bin = GST_BIN_CAST (element);
3554 gboolean res = FALSE;
3555 GstIteratorFoldFunction fold_func;
3556 QueryInitFunction fold_init = NULL;
3557 QueryDoneFunction fold_done = NULL;
3558 QueryFold fold_data;
3561 switch (GST_QUERY_TYPE (query)) {
3562 case GST_QUERY_DURATION:
3564 #ifdef DURATION_CACHING
3568 gst_query_parse_duration (query, &qformat, NULL);
3570 /* find cached duration query */
3571 GST_OBJECT_LOCK (bin);
3572 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3573 GstMessage *message = (GstMessage *) cached->data;
3575 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3576 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3580 gst_message_parse_duration (message, &format, &duration);
3582 /* if cached same format, copy duration in query result */
3583 if (format == qformat) {
3584 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3586 GST_OBJECT_UNLOCK (bin);
3588 gst_query_set_duration (query, qformat, duration);
3594 GST_OBJECT_UNLOCK (bin);
3596 /* no cached value found, iterate and collect durations */
3597 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3598 fold_init = bin_query_min_max_init;
3599 fold_done = bin_query_duration_done;
3602 case GST_QUERY_POSITION:
3604 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3605 fold_init = bin_query_min_max_init;
3606 fold_done = bin_query_position_done;
3609 case GST_QUERY_LATENCY:
3611 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3612 fold_init = bin_query_min_max_init;
3613 fold_done = bin_query_latency_done;
3618 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3622 fold_data.query = query;
3624 /* set the result of the query to FALSE initially */
3625 g_value_init (&ret, G_TYPE_BOOLEAN);
3626 g_value_set_boolean (&ret, res);
3628 iter = gst_bin_iterate_sinks (bin);
3629 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3630 query, GST_QUERY_TYPE_NAME (query));
3633 fold_init (bin, &fold_data);
3636 GstIteratorResult ires;
3638 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3641 case GST_ITERATOR_RESYNC:
3642 gst_iterator_resync (iter);
3644 fold_init (bin, &fold_data);
3645 g_value_set_boolean (&ret, res);
3647 case GST_ITERATOR_OK:
3648 case GST_ITERATOR_DONE:
3649 res = g_value_get_boolean (&ret);
3650 if (fold_done != NULL && res)
3651 fold_done (bin, &fold_data);
3659 gst_iterator_free (iter);
3661 #ifdef DURATION_CACHING
3664 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3670 compare_name (GstElement * element, const gchar * name)
3674 GST_OBJECT_LOCK (element);
3675 eq = strcmp (GST_ELEMENT_NAME (element), name);
3676 GST_OBJECT_UNLOCK (element);
3679 gst_object_unref (element);
3685 * gst_bin_get_by_name:
3687 * @name: the element name to search for
3689 * Gets the element with the given name from a bin. This
3690 * function recurses into child bins.
3692 * Returns NULL if no element with the given name is found in the bin.
3694 * MT safe. Caller owns returned reference.
3696 * Returns: (transfer full): the #GstElement with the given name, or NULL
3699 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3701 GstIterator *children;
3704 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3706 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3707 GST_ELEMENT_NAME (bin), name);
3709 children = gst_bin_iterate_recurse (bin);
3710 result = gst_iterator_find_custom (children,
3711 (GCompareFunc) compare_name, (gpointer) name);
3712 gst_iterator_free (children);
3714 return GST_ELEMENT_CAST (result);
3718 * gst_bin_get_by_name_recurse_up:
3720 * @name: the element name to search for
3722 * Gets the element with the given name from this bin. If the
3723 * element is not found, a recursion is performed on the parent bin.
3726 * - no element with the given name is found in the bin
3728 * MT safe. Caller owns returned reference.
3730 * Returns: (transfer full): the #GstElement with the given name, or NULL
3733 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3737 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3738 g_return_val_if_fail (name != NULL, NULL);
3740 result = gst_bin_get_by_name (bin, name);
3745 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3747 if (GST_IS_BIN (parent)) {
3748 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3750 gst_object_unref (parent);
3758 compare_interface (GstElement * element, gpointer interface)
3760 GType interface_type = (GType) interface;
3763 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3766 /* we did not find the element, need to release the ref
3767 * added by the iterator */
3768 gst_object_unref (element);
3775 * gst_bin_get_by_interface:
3777 * @iface: the #GType of an interface
3779 * Looks for an element inside the bin that implements the given
3780 * interface. If such an element is found, it returns the element.
3781 * You can cast this element to the given interface afterwards. If you want
3782 * all elements that implement the interface, use
3783 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3785 * MT safe. Caller owns returned reference.
3787 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3790 gst_bin_get_by_interface (GstBin * bin, GType iface)
3792 GstIterator *children;
3795 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3796 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3798 children = gst_bin_iterate_recurse (bin);
3799 result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3801 gst_iterator_free (children);
3803 return GST_ELEMENT_CAST (result);
3807 * gst_bin_iterate_all_by_interface:
3809 * @iface: the #GType of an interface
3811 * Looks for all elements inside the bin that implements the given
3812 * interface. You can safely cast all returned elements to the given interface.
3813 * The function recurses inside child bins. The iterator will yield a series
3814 * of #GstElement that should be unreffed after use.
3816 * Each element yielded by the iterator will have its refcount increased, so
3819 * MT safe. Caller owns returned value.
3821 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3822 * in the bin implementing the given interface, or NULL
3825 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3827 GstIterator *children;
3828 GstIterator *result;
3830 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3831 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3833 children = gst_bin_iterate_recurse (bin);
3834 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3840 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
3842 gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
3844 GstBin *bin = GST_BIN_CAST (object);
3845 xmlNodePtr childlist, elementnode;
3849 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
3850 GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
3852 childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
3854 GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
3855 GST_ELEMENT_NAME (bin), bin->numchildren);
3857 children = g_list_last (bin->children);
3859 child = GST_ELEMENT_CAST (children->data);
3860 elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
3861 gst_object_save_thyself (GST_OBJECT (child), elementnode);
3862 children = g_list_previous (children);
3868 gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
3870 GstBin *bin = GST_BIN_CAST (object);
3871 xmlNodePtr field = self->xmlChildrenNode;
3872 xmlNodePtr childlist;
3875 if (!strcmp ((char *) field->name, "children")) {
3876 GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
3877 GST_ELEMENT_NAME (object));
3878 childlist = field->xmlChildrenNode;
3880 if (!strcmp ((char *) childlist->name, "element")) {
3881 /* gst_xml_make_element will gst_bin_add() the element to ourself */
3882 gst_xml_make_element (childlist, GST_OBJECT (bin));
3884 childlist = childlist->next;
3888 field = field->next;
3890 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
3891 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
3893 #endif /* GST_DISABLE_LOADSAVE */