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 /* FIXME 0.11: suppress warnings for deprecated API such as GStaticRecMutex
161 * with newer GLib versions (>= 2.31.0) */
162 #define GLIB_DISABLE_DEPRECATION_WARNINGS
163 #include "gst_private.h"
165 #include "gstevent.h"
167 #include "gstmarshal.h"
170 #include "gsterror.h"
172 #include "gstindex.h"
173 #include "gstindexfactory.h"
174 #include "gstutils.h"
175 #include "gstchildproxy.h"
177 #ifdef GST_DISABLE_DEPRECATED
178 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
180 #define GstXmlNodePtr xmlNodePtr
181 #include <libxml/parser.h>
182 GstXmlNodePtr gst_object_save_thyself (GstObject * object,
183 GstXmlNodePtr parent);
184 void gst_object_restore_thyself (GstObject * object, GstXmlNodePtr parent);
185 GstElement *gst_xml_make_element (xmlNodePtr cur, GstObject * parent);
189 /* enable for DURATION caching.
190 * FIXME currently too many elements don't update
191 * their duration when it changes so we return inaccurate values. */
192 #undef DURATION_CACHING
194 /* latency is by default enabled now.
195 * live-preroll and no-live-preroll in the environment var GST_COMPAT
196 * to enables or disable it respectively.
198 static gboolean enable_latency = TRUE;
200 GST_DEBUG_CATEGORY_STATIC (bin_debug);
201 #define GST_CAT_DEFAULT bin_debug
203 /* a bin is toplevel if it has no parent or when it is configured to behave like
205 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
207 #define GST_BIN_GET_PRIVATE(obj) \
208 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
210 struct _GstBinPrivate
212 gboolean asynchandling;
213 /* if we get an ASYNC_DONE message from ourselves, this means that the
214 * subclass will simulate ASYNC behaviour without having ASYNC children. When
215 * such an ASYNC_DONE message is posted while we are doing a state change, we
216 * have to process the message after finishing the state change even when no
217 * child returned GST_STATE_CHANGE_ASYNC. */
218 gboolean pending_async_done;
220 guint32 structure_cookie;
224 /* forward messages from our children */
225 gboolean message_forward;
237 static void gst_bin_dispose (GObject * object);
239 static void gst_bin_set_property (GObject * object, guint prop_id,
240 const GValue * value, GParamSpec * pspec);
241 static void gst_bin_get_property (GObject * object, guint prop_id,
242 GValue * value, GParamSpec * pspec);
244 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
245 GstStateChange transition);
246 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
247 GstState newstate, GstState pending);
248 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
249 GstState * state, GstState * pending, GstClockTime timeout);
250 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
251 gboolean flag_pending);
252 static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
253 static void bin_push_state_continue (BinContinueData * data);
254 static void bin_do_eos (GstBin * bin);
256 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
257 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
259 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
260 static GstIndex *gst_bin_get_index_func (GstElement * element);
262 static GstClock *gst_bin_provide_clock_func (GstElement * element);
263 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
265 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
266 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
267 static GstBusSyncReply bin_bus_handler (GstBus * bus,
268 GstMessage * message, GstBin * bin);
269 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
271 static gboolean gst_bin_do_latency_func (GstBin * bin);
273 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
274 static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
275 static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
278 static void bin_remove_messages (GstBin * bin, GstObject * src,
279 GstMessageType types);
280 static void gst_bin_continue_func (BinContinueData * data);
281 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
282 static gint bin_element_is_src (GstElement * child, GstBin * bin);
284 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
286 /* Bin signals and properties */
295 #define DEFAULT_ASYNC_HANDLING FALSE
296 #define DEFAULT_MESSAGE_FORWARD FALSE
302 PROP_MESSAGE_FORWARD,
306 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
308 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
310 #define _do_init(type) \
312 const gchar *compat; \
313 static const GInterfaceInfo iface_info = { \
314 gst_bin_child_proxy_init, \
318 g_type_add_interface_static (type, GST_TYPE_CHILD_PROXY, &iface_info); \
320 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
321 "debugging info for the 'bin' container element"); \
323 /* compatibility stuff */ \
324 compat = g_getenv ("GST_COMPAT"); \
325 if (compat != NULL) { \
326 if (strstr (compat, "no-live-preroll")) \
327 enable_latency = FALSE; \
328 else if (strstr (compat, "live-preroll")) \
329 enable_latency = TRUE; \
333 GST_BOILERPLATE_FULL (GstBin, gst_bin, GstElement, GST_TYPE_ELEMENT, _do_init);
336 gst_bin_base_init (gpointer g_class)
338 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
340 gst_element_class_set_details_simple (gstelement_class, "Generic bin",
342 "Simple container object",
343 "Erik Walthinsen <omega@cse.ogi.edu>,"
344 "Wim Taymans <wim.taymans@gmail.com>");
348 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
354 bin = GST_BIN_CAST (child_proxy);
356 GST_OBJECT_LOCK (bin);
357 if ((res = g_list_nth_data (bin->children, index)))
358 gst_object_ref (res);
359 GST_OBJECT_UNLOCK (bin);
365 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
370 bin = GST_BIN_CAST (child_proxy);
372 GST_OBJECT_LOCK (bin);
373 num = bin->numchildren;
374 GST_OBJECT_UNLOCK (bin);
380 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
382 GstChildProxyInterface *iface = g_iface;
384 iface->get_children_count = gst_bin_child_proxy_get_children_count;
385 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
389 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
390 GValue * return_accu, const GValue * handler_return, gpointer dummy)
394 myboolean = g_value_get_boolean (handler_return);
395 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
396 g_value_set_boolean (return_accu, myboolean);
398 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
405 gst_bin_class_init (GstBinClass * klass)
407 GObjectClass *gobject_class = (GObjectClass *) klass;
408 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
409 GstObjectClass *gstobject_class = (GstObjectClass *) klass;
411 GstElementClass *gstelement_class = (GstElementClass *) klass;
414 g_type_class_add_private (klass, sizeof (GstBinPrivate));
416 gobject_class->set_property = gst_bin_set_property;
417 gobject_class->get_property = gst_bin_get_property;
420 * GstBin:async-handling
422 * If set to #TRUE, the bin will handle asynchronous state changes.
423 * This should be used only if the bin subclass is modifying the state
424 * of its children on its own.
428 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
429 g_param_spec_boolean ("async-handling", "Async Handling",
430 "The bin will handle Asynchronous state changes",
431 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
434 * GstBin::element-added:
436 * @element: the #GstElement that was added to the bin
438 * Will be emitted after the element was added to the bin.
440 gst_bin_signals[ELEMENT_ADDED] =
441 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
442 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
443 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
445 * GstBin::element-removed:
447 * @element: the #GstElement that was removed from the bin
449 * Will be emitted after the element was removed from the bin.
451 gst_bin_signals[ELEMENT_REMOVED] =
452 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
453 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
454 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
456 * GstBin::do-latency:
459 * Will be emitted when the bin needs to perform latency calculations. This
460 * signal is only emited for toplevel bins or when async-handling is
463 * Only one signal handler is invoked. If no signals are connected, the
464 * default handler is invoked, which will query and distribute the lowest
465 * possible latency to all sinks.
467 * Connect to this signal if the default latency calculations are not
468 * sufficient, like when you need different latencies for different sinks in
473 gst_bin_signals[DO_LATENCY] =
474 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
475 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
476 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
477 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
480 * GstBin:message-forward
482 * Forward all children messages, even those that would normally be filtered by
483 * the bin. This can be interesting when one wants to be notified of the EOS
484 * state of individual elements, for example.
486 * The messages are converted to an ELEMENT message with the bin as the
487 * source. The structure of the message is named 'GstBinForwarded' and contains
488 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
493 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
494 g_param_spec_boolean ("message-forward", "Message Forward",
495 "Forwards all children messages",
496 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
498 gobject_class->dispose = gst_bin_dispose;
500 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
501 gstobject_class->save_thyself =
502 ((gpointer (*)(GstObject * object,
503 gpointer self)) * GST_DEBUG_FUNCPTR (gst_bin_save_thyself));
504 gstobject_class->restore_thyself =
505 ((void (*)(GstObject * object,
506 gpointer self)) *GST_DEBUG_FUNCPTR (gst_bin_restore_thyself));
509 gstelement_class->change_state =
510 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
511 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
512 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
513 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
514 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
515 gstelement_class->provide_clock =
516 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
517 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
519 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
520 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
522 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
523 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
524 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
526 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
528 GST_DEBUG ("creating bin thread pool");
531 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
533 g_critical ("could alloc threadpool %s", err->message);
538 gst_bin_init (GstBin * bin, GstBinClass * klass)
542 bin->numchildren = 0;
543 bin->children = NULL;
544 bin->children_cookie = 0;
545 bin->messages = NULL;
546 bin->provided_clock = NULL;
547 bin->clock_dirty = FALSE;
549 /* Set up a bus for listening to child elements */
550 bus = gst_bus_new ();
551 bin->child_bus = bus;
552 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
554 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
556 bin->priv = GST_BIN_GET_PRIVATE (bin);
557 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
558 bin->priv->structure_cookie = 0;
559 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
563 gst_bin_dispose (GObject * object)
565 GstBin *bin = GST_BIN_CAST (object);
566 GstBus **child_bus_p = &bin->child_bus;
567 GstClock **provided_clock_p = &bin->provided_clock;
568 GstElement **clock_provider_p = &bin->clock_provider;
569 GstIndex **index_p = &bin->priv->index;
571 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
573 GST_OBJECT_LOCK (object);
574 gst_object_replace ((GstObject **) child_bus_p, NULL);
575 gst_object_replace ((GstObject **) provided_clock_p, NULL);
576 gst_object_replace ((GstObject **) clock_provider_p, NULL);
577 gst_object_replace ((GstObject **) index_p, NULL);
578 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
579 GST_OBJECT_UNLOCK (object);
581 while (bin->children) {
582 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
584 if (G_UNLIKELY (bin->children != NULL)) {
585 g_critical ("could not remove elements from bin '%s'",
586 GST_STR_NULL (GST_OBJECT_NAME (object)));
589 G_OBJECT_CLASS (parent_class)->dispose (object);
594 * @name: the name of the new bin
596 * Creates a new bin with the given name.
598 * Returns: (transfer full): a new #GstBin
601 gst_bin_new (const gchar * name)
603 return gst_element_factory_make ("bin", name);
607 gst_bin_set_property (GObject * object, guint prop_id,
608 const GValue * value, GParamSpec * pspec)
612 gstbin = GST_BIN_CAST (object);
615 case PROP_ASYNC_HANDLING:
616 GST_OBJECT_LOCK (gstbin);
617 gstbin->priv->asynchandling = g_value_get_boolean (value);
618 GST_OBJECT_UNLOCK (gstbin);
620 case PROP_MESSAGE_FORWARD:
621 GST_OBJECT_LOCK (gstbin);
622 gstbin->priv->message_forward = g_value_get_boolean (value);
623 GST_OBJECT_UNLOCK (gstbin);
626 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
632 gst_bin_get_property (GObject * object, guint prop_id,
633 GValue * value, GParamSpec * pspec)
637 gstbin = GST_BIN_CAST (object);
640 case PROP_ASYNC_HANDLING:
641 GST_OBJECT_LOCK (gstbin);
642 g_value_set_boolean (value, gstbin->priv->asynchandling);
643 GST_OBJECT_UNLOCK (gstbin);
645 case PROP_MESSAGE_FORWARD:
646 GST_OBJECT_LOCK (gstbin);
647 g_value_set_boolean (value, gstbin->priv->message_forward);
648 GST_OBJECT_UNLOCK (gstbin);
651 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
656 /* return the cached index */
658 gst_bin_get_index_func (GstElement * element)
663 bin = GST_BIN_CAST (element);
665 GST_OBJECT_LOCK (bin);
666 if ((result = bin->priv->index))
667 gst_object_ref (result);
668 GST_OBJECT_UNLOCK (bin);
673 /* set the index on all elements in this bin
678 gst_bin_set_index_func (GstElement * element, GstIndex * index)
685 bin = GST_BIN_CAST (element);
687 GST_OBJECT_LOCK (bin);
688 old = bin->priv->index;
689 if (G_UNLIKELY (old == index))
692 gst_object_ref (index);
693 bin->priv->index = index;
694 GST_OBJECT_UNLOCK (bin);
697 gst_object_unref (old);
699 it = gst_bin_iterate_elements (bin);
701 /* set the index on all elements in the bin */
706 switch (gst_iterator_next (it, &data)) {
707 case GST_ITERATOR_OK:
709 GstElement *child = GST_ELEMENT_CAST (data);
711 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
712 GST_ELEMENT_NAME (child));
713 gst_element_set_index (child, index);
715 gst_object_unref (child);
718 case GST_ITERATOR_RESYNC:
719 GST_DEBUG_OBJECT (bin, "iterator doing resync");
720 gst_iterator_resync (it);
723 case GST_ITERATOR_DONE:
724 GST_DEBUG_OBJECT (bin, "iterator done");
729 gst_iterator_free (it);
734 GST_DEBUG_OBJECT (bin, "index was already set");
735 GST_OBJECT_UNLOCK (bin);
740 /* set the clock on all elements in this bin
745 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
752 bin = GST_BIN_CAST (element);
754 it = gst_bin_iterate_elements (bin);
760 switch (gst_iterator_next (it, &data)) {
761 case GST_ITERATOR_OK:
763 GstElement *child = GST_ELEMENT_CAST (data);
765 res &= gst_element_set_clock (child, clock);
767 gst_object_unref (child);
770 case GST_ITERATOR_RESYNC:
771 GST_DEBUG_OBJECT (bin, "iterator doing resync");
772 gst_iterator_resync (it);
776 case GST_ITERATOR_DONE:
777 GST_DEBUG_OBJECT (bin, "iterator done");
782 gst_iterator_free (it);
787 /* get the clock for this bin by asking all of the children in this bin
789 * The ref of the returned clock in increased so unref after usage.
791 * We loop the elements in state order and pick the last clock we can
792 * get. This makes sure we get a clock from the source.
797 gst_bin_provide_clock_func (GstElement * element)
799 GstClock *result = NULL;
800 GstElement *provider = NULL;
804 GstClock **provided_clock_p;
805 GstElement **clock_provider_p;
807 bin = GST_BIN_CAST (element);
809 GST_OBJECT_LOCK (bin);
810 if (!bin->clock_dirty)
813 GST_DEBUG_OBJECT (bin, "finding new clock");
815 it = gst_bin_sort_iterator_new (bin);
817 while (it->next (it, &val) == GST_ITERATOR_OK) {
818 GstElement *child = GST_ELEMENT_CAST (val);
821 clock = gst_element_provide_clock (child);
823 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
824 clock, GST_ELEMENT_NAME (child));
826 gst_object_unref (result);
827 gst_object_unref (provider);
832 gst_object_unref (child);
836 provided_clock_p = &bin->provided_clock;
837 clock_provider_p = &bin->clock_provider;
838 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
839 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
840 bin->clock_dirty = FALSE;
841 GST_DEBUG_OBJECT (bin,
842 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
844 /* Provider is not being returned to caller, just the result */
846 gst_object_unref (provider);
847 GST_OBJECT_UNLOCK (bin);
849 gst_iterator_free (it);
855 if ((result = bin->provided_clock))
856 gst_object_ref (result);
857 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
858 GST_OBJECT_UNLOCK (bin);
865 * functions for manipulating cached messages
870 GstMessageType types;
873 /* check if a message is of given src and type */
875 message_check (GstMessage * message, MessageFind * target)
880 eq &= GST_MESSAGE_SRC (message) == target->src;
882 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
883 GST_LOG ("looking at message %p: %d", message, eq);
889 find_message (GstBin * bin, GstObject * src, GstMessageType types)
897 result = g_list_find_custom (bin->messages, &find,
898 (GCompareFunc) message_check);
901 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
902 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
905 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
906 #ifndef GST_DISABLE_GST_DEBUG
910 for (i = 0; i < 32; i++)
911 if (types & (1 << i))
912 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
920 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
923 * A message that is cached and has the same SRC and type is replaced
924 * by the given message.
927 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
933 if ((src = GST_MESSAGE_SRC (message))) {
934 /* first find the previous message posted by this element */
935 if ((previous = find_message (bin, src, types))) {
936 GstMessage *previous_msg;
938 /* if we found a previous message, replace it */
939 previous_msg = previous->data;
940 previous->data = message;
942 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
943 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
944 GST_MESSAGE_TYPE_NAME (message));
946 gst_message_unref (previous_msg);
948 /* keep new message */
949 bin->messages = g_list_prepend (bin->messages, message);
951 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
952 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
955 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
956 GST_MESSAGE_TYPE_NAME (message));
958 gst_message_unref (message);
963 /* with LOCK. Remove all messages of given types */
965 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
973 for (walk = bin->messages; walk; walk = next) {
974 GstMessage *message = (GstMessage *) walk->data;
976 next = g_list_next (walk);
978 if (message_check (message, &find) == 0) {
979 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
980 "deleting message %p of types 0x%08x", message, types);
981 bin->messages = g_list_delete_link (bin->messages, walk);
982 gst_message_unref (message);
984 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
985 "not deleting message %p of type 0x%08x", message,
986 GST_MESSAGE_TYPE (message));
992 /* Check if the bin is EOS. We do this by scanning all sinks and
993 * checking if they posted an EOS message.
995 * call with bin LOCK */
997 is_eos (GstBin * bin, guint32 * seqnum)
1004 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1005 GstElement *element;
1007 element = GST_ELEMENT_CAST (walk->data);
1008 if (bin_element_is_sink (element, bin) == 0) {
1009 /* check if element posted EOS */
1011 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
1012 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1013 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1016 GST_DEBUG ("sink '%s' did not post EOS yet",
1017 GST_ELEMENT_NAME (element));
1023 /* FIXME: Some tests (e.g. elements/capsfilter) use
1024 * pipelines with a dangling sinkpad but no sink element.
1025 * These tests assume that no EOS message is ever
1026 * posted on the bus so let's keep that behaviour.
1027 * In valid pipelines this doesn't make a difference.
1029 return result && n_eos > 0;
1033 unlink_pads (GstPad * pad)
1037 if ((peer = gst_pad_get_peer (pad))) {
1038 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1039 gst_pad_unlink (pad, peer);
1041 gst_pad_unlink (peer, pad);
1042 gst_object_unref (peer);
1044 gst_object_unref (pad);
1047 /* vmethod that adds an element to a bin
1052 gst_bin_add_func (GstBin * bin, GstElement * element)
1056 gboolean is_sink, is_source;
1057 GstMessage *clock_message = NULL, *async_message = NULL;
1058 GstStateChangeReturn ret;
1060 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1062 /* we obviously can't add ourself to ourself */
1063 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1066 /* get the element name to make sure it is unique in this bin. */
1067 GST_OBJECT_LOCK (element);
1068 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1069 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1070 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1071 GST_OBJECT_UNLOCK (element);
1073 GST_OBJECT_LOCK (bin);
1075 /* then check to see if the element's name is already taken in the bin,
1076 * we can safely take the lock here. This check is probably bogus because
1077 * you can safely change the element name after this check and before setting
1078 * the object parent. The window is very small though... */
1079 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1080 goto duplicate_name;
1082 /* set the element's parent and add the element to the bin's list of children */
1083 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1084 GST_OBJECT_CAST (bin))))
1087 /* if we add a sink we become a sink */
1089 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1091 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1094 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1096 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1098 if (gst_element_provides_clock (element)) {
1099 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1101 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1104 bin->children = g_list_prepend (bin->children, element);
1106 bin->children_cookie++;
1107 bin->priv->structure_cookie++;
1109 /* distribute the bus */
1110 gst_element_set_bus (element, bin->child_bus);
1112 /* propagate the current base_time, start_time and clock */
1113 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1114 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1115 /* it's possible that the element did not accept the clock but
1116 * that is not important right now. When the pipeline goes to PLAYING,
1117 * a new clock will be selected */
1118 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1119 /* set the cached index on the children */
1120 if (bin->priv->index)
1121 gst_element_set_index (element, bin->priv->index);
1123 ret = GST_STATE_RETURN (bin);
1124 /* no need to update the state if we are in error */
1125 if (ret == GST_STATE_CHANGE_FAILURE)
1126 goto no_state_recalc;
1128 /* update the bin state, the new element could have been an ASYNC or
1129 * NO_PREROLL element */
1130 ret = GST_STATE_RETURN (element);
1131 GST_DEBUG_OBJECT (bin, "added %s element",
1132 gst_element_state_change_return_get_name (ret));
1135 case GST_STATE_CHANGE_ASYNC:
1137 /* create message to track this aync element when it posts an async-done
1140 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1143 case GST_STATE_CHANGE_NO_PREROLL:
1144 /* ignore all async elements we might have and commit our state */
1145 bin_handle_async_done (bin, ret, FALSE);
1147 case GST_STATE_CHANGE_FAILURE:
1154 GST_OBJECT_UNLOCK (bin);
1156 /* post the messages on the bus of the element so that the bin can handle
1159 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1162 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1164 /* unlink all linked pads */
1165 it = gst_element_iterate_pads (element);
1166 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1167 gst_iterator_free (it);
1169 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1173 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1174 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1178 /* ERROR handling here */
1181 GST_OBJECT_LOCK (bin);
1182 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1183 GST_OBJECT_UNLOCK (bin);
1188 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1189 elem_name, GST_ELEMENT_NAME (bin));
1190 GST_OBJECT_UNLOCK (bin);
1196 g_warning ("Element '%s' already has parent", elem_name);
1197 GST_OBJECT_UNLOCK (bin);
1206 * @element: (transfer full): the #GstElement to add
1208 * Adds the given element to the bin. Sets the element's parent, and thus
1209 * takes ownership of the element. An element can only be added to one bin.
1211 * If the element's pads are linked to other pads, the pads will be unlinked
1212 * before the element is added to the bin.
1215 * When you add an element to an already-running pipeline, you will have to
1216 * take care to set the state of the newly-added element to the desired
1217 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1218 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1219 * The bin or pipeline will not take care of this for you.
1224 * Returns: TRUE if the element could be added, FALSE if
1225 * the bin does not want to accept the element.
1228 gst_bin_add (GstBin * bin, GstElement * element)
1230 GstBinClass *bclass;
1233 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1234 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1236 bclass = GST_BIN_GET_CLASS (bin);
1238 if (G_UNLIKELY (bclass->add_element == NULL))
1241 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1242 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1243 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1245 result = bclass->add_element (bin, element);
1249 /* ERROR handling */
1252 g_warning ("adding elements to bin '%s' is not supported",
1253 GST_ELEMENT_NAME (bin));
1258 /* remove an element from the bin
1263 gst_bin_remove_func (GstBin * bin, GstElement * element)
1267 gboolean is_sink, is_source, othersink, othersource, found;
1268 GstMessage *clock_message = NULL;
1269 GstClock **provided_clock_p;
1270 GstElement **clock_provider_p;
1272 gboolean other_async, this_async, have_no_preroll;
1273 GstStateChangeReturn ret;
1275 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1277 GST_OBJECT_LOCK (element);
1278 /* Check if the element is already being removed and immediately
1280 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1281 goto already_removing;
1283 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1284 /* grab element name so we can print it */
1285 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1286 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1287 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1288 GST_OBJECT_UNLOCK (element);
1290 /* unlink all linked pads */
1291 it = gst_element_iterate_pads (element);
1292 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1293 gst_iterator_free (it);
1295 GST_OBJECT_LOCK (bin);
1298 othersource = FALSE;
1299 have_no_preroll = FALSE;
1300 /* iterate the elements, we collect which ones are async and no_preroll. We
1301 * also remove the element when we find it. */
1302 for (walk = bin->children; walk; walk = next) {
1303 GstElement *child = GST_ELEMENT_CAST (walk->data);
1305 next = g_list_next (walk);
1307 if (child == element) {
1309 /* remove the element */
1310 bin->children = g_list_delete_link (bin->children, walk);
1312 gboolean child_sink, child_source;
1314 GST_OBJECT_LOCK (child);
1315 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1316 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1317 /* when we remove a sink, check if there are other sinks. */
1318 if (is_sink && !othersink && child_sink)
1320 if (is_source && !othersource && child_source)
1322 /* check if we have NO_PREROLL children */
1323 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1324 have_no_preroll = TRUE;
1325 GST_OBJECT_UNLOCK (child);
1329 /* the element must have been in the bin's list of children */
1330 if (G_UNLIKELY (!found))
1333 /* we now removed the element from the list of elements, increment the cookie
1334 * so that others can detect a change in the children list. */
1336 bin->children_cookie++;
1337 bin->priv->structure_cookie++;
1339 if (is_sink && !othersink) {
1340 /* we're not a sink anymore */
1341 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1342 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1344 if (is_source && !othersource) {
1345 /* we're not a source anymore */
1346 GST_DEBUG_OBJECT (bin, "we removed the last source");
1347 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1351 /* if the clock provider for this element is removed, we lost
1352 * the clock as well, we need to inform the parent of this
1353 * so that it can select a new clock */
1354 if (bin->clock_provider == element) {
1355 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1356 bin->clock_dirty = TRUE;
1358 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1359 provided_clock_p = &bin->provided_clock;
1360 clock_provider_p = &bin->clock_provider;
1361 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1362 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1365 /* remove messages for the element, if there was a pending ASYNC_START
1366 * message we must see if removing the element caused the bin to lose its
1369 other_async = FALSE;
1370 for (walk = bin->messages; walk; walk = next) {
1371 GstMessage *message = (GstMessage *) walk->data;
1372 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1375 next = g_list_next (walk);
1378 switch (GST_MESSAGE_TYPE (message)) {
1379 case GST_MESSAGE_ASYNC_START:
1385 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1387 case GST_MESSAGE_STRUCTURE_CHANGE:
1391 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1393 /* it's unlikely that this message is still in the list of messages
1394 * because this would mean that a link/unlink is busy in another thread
1395 * while we remove the element. We still have to remove the message
1396 * because we might not receive the done message anymore when the element
1397 * is removed from the bin. */
1398 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1399 if (owner == element)
1410 /* delete all message types */
1411 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1412 message, elem_name);
1413 bin->messages = g_list_delete_link (bin->messages, walk);
1414 gst_message_unref (message);
1418 /* get last return */
1419 ret = GST_STATE_RETURN (bin);
1421 /* no need to update the state if we are in error */
1422 if (ret == GST_STATE_CHANGE_FAILURE)
1423 goto no_state_recalc;
1425 if (!other_async && this_async) {
1426 /* all other elements were not async and we removed the async one,
1427 * handle the async-done case because we are not async anymore now. */
1428 GST_DEBUG_OBJECT (bin,
1429 "we removed the last async element, have no_preroll %d",
1432 /* the current state return of the bin depends on if there are no_preroll
1433 * elements in the pipeline or not */
1434 if (have_no_preroll)
1435 ret = GST_STATE_CHANGE_NO_PREROLL;
1437 ret = GST_STATE_CHANGE_SUCCESS;
1439 bin_handle_async_done (bin, ret, FALSE);
1441 GST_DEBUG_OBJECT (bin,
1442 "recalc state preroll: %d, other async: %d, this async %d",
1443 have_no_preroll, other_async, this_async);
1445 if (have_no_preroll) {
1446 ret = GST_STATE_CHANGE_NO_PREROLL;
1447 } else if (other_async) {
1448 /* there are other async elements and we were not doing an async state
1449 * change, change our pending state and go async */
1450 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1451 GST_STATE_NEXT (bin) = GST_STATE (bin);
1452 GST_STATE_PENDING (bin) = GST_STATE (bin);
1454 ret = GST_STATE_CHANGE_ASYNC;
1456 GST_STATE_RETURN (bin) = ret;
1459 GST_OBJECT_UNLOCK (bin);
1462 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1464 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1468 gst_element_set_bus (element, NULL);
1470 /* Clear the clock we provided to the element */
1471 gst_element_set_clock (element, NULL);
1473 /* we ref here because after the _unparent() the element can be disposed
1474 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1475 gst_object_ref (element);
1476 gst_object_unparent (GST_OBJECT_CAST (element));
1478 GST_OBJECT_LOCK (element);
1479 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1480 GST_OBJECT_UNLOCK (element);
1482 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1483 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1485 /* element is really out of our control now */
1486 gst_object_unref (element);
1490 /* ERROR handling */
1493 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1494 GST_ELEMENT_NAME (bin));
1495 GST_OBJECT_UNLOCK (bin);
1501 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1502 GST_OBJECT_UNLOCK (element);
1510 * @element: (transfer none): the #GstElement to remove
1512 * Removes the element from the bin, unparenting it as well.
1513 * Unparenting the element means that the element will be dereferenced,
1514 * so if the bin holds the only reference to the element, the element
1515 * will be freed in the process of removing it from the bin. If you
1516 * want the element to still exist after removing, you need to call
1517 * gst_object_ref() before removing it from the bin.
1519 * If the element's pads are linked to other pads, the pads will be unlinked
1520 * before the element is removed from the bin.
1524 * Returns: TRUE if the element could be removed, FALSE if
1525 * the bin does not want to remove the element.
1528 gst_bin_remove (GstBin * bin, GstElement * element)
1530 GstBinClass *bclass;
1533 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1534 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1536 bclass = GST_BIN_GET_CLASS (bin);
1538 if (G_UNLIKELY (bclass->remove_element == NULL))
1541 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1542 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1544 result = bclass->remove_element (bin, element);
1548 /* ERROR handling */
1551 g_warning ("removing elements from bin '%s' is not supported",
1552 GST_ELEMENT_NAME (bin));
1557 static GstIteratorItem
1558 iterate_child (GstIterator * it, GstElement * child)
1560 gst_object_ref (child);
1561 return GST_ITERATOR_ITEM_PASS;
1565 * gst_bin_iterate_elements:
1568 * Gets an iterator for the elements in this bin.
1570 * Each element yielded by the iterator will have its refcount increased, so
1573 * MT safe. Caller owns returned value.
1575 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1578 gst_bin_iterate_elements (GstBin * bin)
1580 GstIterator *result;
1582 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1584 GST_OBJECT_LOCK (bin);
1585 /* add ref because the iterator refs the bin. When the iterator
1586 * is freed it will unref the bin again using the provided dispose
1588 gst_object_ref (bin);
1589 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1590 GST_OBJECT_GET_LOCK (bin),
1591 &bin->children_cookie,
1594 (GstIteratorItemFunction) iterate_child,
1595 (GstIteratorDisposeFunction) gst_object_unref);
1596 GST_OBJECT_UNLOCK (bin);
1601 static GstIteratorItem
1602 iterate_child_recurse (GstIterator * it, GstElement * child)
1604 gst_object_ref (child);
1605 if (GST_IS_BIN (child)) {
1606 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1608 gst_iterator_push (it, other);
1610 return GST_ITERATOR_ITEM_PASS;
1614 * gst_bin_iterate_recurse:
1617 * Gets an iterator for the elements in this bin.
1618 * This iterator recurses into GstBin children.
1620 * Each element yielded by the iterator will have its refcount increased, so
1623 * MT safe. Caller owns returned value.
1625 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1628 gst_bin_iterate_recurse (GstBin * bin)
1630 GstIterator *result;
1632 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1634 GST_OBJECT_LOCK (bin);
1635 /* add ref because the iterator refs the bin. When the iterator
1636 * is freed it will unref the bin again using the provided dispose
1638 gst_object_ref (bin);
1639 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1640 GST_OBJECT_GET_LOCK (bin),
1641 &bin->children_cookie,
1644 (GstIteratorItemFunction) iterate_child_recurse,
1645 (GstIteratorDisposeFunction) gst_object_unref);
1646 GST_OBJECT_UNLOCK (bin);
1651 /* returns 0 when TRUE because this is a GCompareFunc */
1654 bin_element_is_sink (GstElement * child, GstBin * bin)
1658 /* we lock the child here for the remainder of the function to
1659 * get its name and flag safely. */
1660 GST_OBJECT_LOCK (child);
1661 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1663 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1664 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1666 GST_OBJECT_UNLOCK (child);
1667 return is_sink ? 0 : 1;
1671 sink_iterator_filter (GstElement * child, GstBin * bin)
1673 if (bin_element_is_sink (child, bin) == 0) {
1674 /* returns 0 because this is a GCompareFunc */
1677 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1679 gst_object_unref (child);
1685 * gst_bin_iterate_sinks:
1688 * Gets an iterator for all elements in the bin that have the
1689 * #GST_ELEMENT_IS_SINK flag set.
1691 * Each element yielded by the iterator will have its refcount increased, so
1694 * MT safe. Caller owns returned value.
1696 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1699 gst_bin_iterate_sinks (GstBin * bin)
1701 GstIterator *children;
1702 GstIterator *result;
1704 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1706 children = gst_bin_iterate_elements (bin);
1707 result = gst_iterator_filter (children,
1708 (GCompareFunc) sink_iterator_filter, bin);
1713 /* returns 0 when TRUE because this is a GCompareFunc */
1716 bin_element_is_src (GstElement * child, GstBin * bin)
1720 /* we lock the child here for the remainder of the function to
1721 * get its name and other info safely. */
1722 GST_OBJECT_LOCK (child);
1723 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1725 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1726 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1728 GST_OBJECT_UNLOCK (child);
1729 return is_src ? 0 : 1;
1733 src_iterator_filter (GstElement * child, GstBin * bin)
1735 if (bin_element_is_src (child, bin) == 0) {
1736 /* returns 0 because this is a GCompareFunc */
1739 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1741 gst_object_unref (child);
1747 * gst_bin_iterate_sources:
1750 * Gets an iterator for all elements in the bin that have the
1751 * #GST_ELEMENT_IS_SOURCE flag set.
1753 * Each element yielded by the iterator will have its refcount increased, so
1756 * MT safe. Caller owns returned value.
1758 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1761 gst_bin_iterate_sources (GstBin * bin)
1763 GstIterator *children;
1764 GstIterator *result;
1766 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1768 children = gst_bin_iterate_elements (bin);
1769 result = gst_iterator_filter (children,
1770 (GCompareFunc) src_iterator_filter, bin);
1778 static GstStateChangeReturn
1779 gst_bin_get_state_func (GstElement * element, GstState * state,
1780 GstState * pending, GstClockTime timeout)
1782 GstStateChangeReturn ret;
1784 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1786 ret = parent_class->get_state (element, state, pending, timeout);
1791 /***********************************************
1792 * Topologically sorted iterator
1793 * see http://en.wikipedia.org/wiki/Topological_sorting
1795 * For each element in the graph, an entry is kept in a HashTable
1796 * with its number of srcpad connections (degree).
1797 * We then change state of all elements without dependencies
1798 * (degree 0) and decrement the degree of all elements connected
1799 * on the sinkpads. When an element reaches degree 0, its state is
1801 * When all elements are handled the algorithm stops.
1803 typedef struct _GstBinSortIterator
1806 GQueue queue; /* elements queued for state change */
1807 GstBin *bin; /* bin we iterate */
1808 gint mode; /* adding or removing dependency */
1809 GstElement *best; /* next element with least dependencies */
1810 gint best_deg; /* best degree */
1811 GHashTable *hash; /* hashtable with element dependencies */
1812 gboolean dirty; /* we detected structure change */
1813 } GstBinSortIterator;
1815 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1816 #define HASH_SET_DEGREE(bit, elem, deg) \
1817 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1818 #define HASH_GET_DEGREE(bit, elem) \
1819 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1821 /* add element to queue of next elements in the iterator.
1822 * We push at the tail to give higher priority elements a
1825 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1827 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1828 GST_ELEMENT_NAME (element));
1829 gst_object_ref (element);
1830 g_queue_push_tail (&bit->queue, element);
1831 HASH_SET_DEGREE (bit, element, -1);
1835 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1839 if ((find = g_queue_find (&bit->queue, element))) {
1840 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1841 GST_ELEMENT_NAME (element));
1843 g_queue_delete_link (&bit->queue, find);
1844 gst_object_unref (element);
1846 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1847 GST_ELEMENT_NAME (element));
1851 /* clear the queue, unref all objects as we took a ref when
1852 * we added them to the queue */
1854 clear_queue (GQueue * queue)
1858 while ((p = g_queue_pop_head (queue)))
1859 gst_object_unref (p);
1862 /* set all degrees to 0. Elements marked as a sink are
1863 * added to the queue immediately. Since we only look at the SINK flag of the
1864 * element, it is possible that we add non-sinks to the queue. These will be
1865 * removed from the queue again when we can prove that it provides data for some
1868 reset_degree (GstElement * element, GstBinSortIterator * bit)
1872 /* sinks are added right away */
1873 GST_OBJECT_LOCK (element);
1874 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1875 GST_OBJECT_UNLOCK (element);
1878 add_to_queue (bit, element);
1880 /* others are marked with 0 and handled when sinks are done */
1881 HASH_SET_DEGREE (bit, element, 0);
1885 /* adjust the degree of all elements connected to the given
1886 * element. If a degree of an element drops to 0, it is
1887 * added to the queue of elements to schedule next.
1889 * We have to make sure not to cross the bin boundary this element
1893 update_degree (GstElement * element, GstBinSortIterator * bit)
1895 gboolean linked = FALSE;
1897 GST_OBJECT_LOCK (element);
1898 /* don't touch degree if element has no sinkpads */
1899 if (element->numsinkpads != 0) {
1900 /* loop over all sinkpads, decrement degree for all connected
1901 * elements in this bin */
1904 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1907 pad = GST_PAD_CAST (pads->data);
1909 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1910 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1911 GST_MESSAGE_STRUCTURE_CHANGE))) {
1912 /* mark the iterator as dirty because we won't be updating the degree
1913 * of the peer parent now. This would result in the 'loop detected'
1914 * later on because the peer parent element could become the best next
1915 * element with a degree > 0. We will simply continue our state
1916 * changes and we'll eventually resync when the unlink completed and
1917 * the iterator cookie is updated. */
1922 if ((peer = gst_pad_get_peer (pad))) {
1923 GstElement *peer_element;
1925 if ((peer_element = gst_pad_get_parent_element (peer))) {
1926 GST_OBJECT_LOCK (peer_element);
1927 /* check that we don't go outside of this bin */
1928 if (GST_OBJECT_CAST (peer_element)->parent ==
1929 GST_OBJECT_CAST (bit->bin)) {
1930 gint old_deg, new_deg;
1932 old_deg = HASH_GET_DEGREE (bit, peer_element);
1934 /* check to see if we added an element as sink that was not really a
1935 * sink because it was connected to some other element. */
1936 if (old_deg == -1) {
1937 remove_from_queue (bit, peer_element);
1940 new_deg = old_deg + bit->mode;
1942 GST_DEBUG_OBJECT (bit->bin,
1943 "change element %s, degree %d->%d, linked to %s",
1944 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1945 GST_ELEMENT_NAME (element));
1947 /* update degree, it is possible that an element was in 0 and
1948 * reaches -1 here. This would mean that the element had no sinkpads
1949 * but became linked while the state change was happening. We will
1950 * resync on this with the structure change message. */
1952 /* degree hit 0, add to queue */
1953 add_to_queue (bit, peer_element);
1955 HASH_SET_DEGREE (bit, peer_element, new_deg);
1959 GST_OBJECT_UNLOCK (peer_element);
1960 gst_object_unref (peer_element);
1962 gst_object_unref (peer);
1967 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1968 GST_ELEMENT_NAME (element));
1970 GST_OBJECT_UNLOCK (element);
1973 /* find the next best element not handled yet. This is the one
1974 * with the lowest non-negative degree */
1976 find_element (GstElement * element, GstBinSortIterator * bit)
1980 /* element is already handled */
1981 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1984 /* first element or element with smaller degree */
1985 if (bit->best == NULL || bit->best_deg > degree) {
1986 bit->best = element;
1987 bit->best_deg = degree;
1991 /* get next element in iterator. the returned element has the
1992 * refcount increased */
1993 static GstIteratorResult
1994 gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
1996 GstBin *bin = bit->bin;
1998 /* empty queue, we have to find a next best element */
1999 if (g_queue_is_empty (&bit->queue)) {
2003 bit->best_deg = G_MAXINT;
2004 g_list_foreach (bin->children, (GFunc) find_element, bit);
2005 if ((best = bit->best)) {
2006 /* when we detected an unlink, don't warn because our degrees might be
2007 * screwed up. We will resync later */
2008 if (bit->best_deg != 0 && !bit->dirty) {
2009 /* we don't fail on this one yet */
2010 GST_WARNING_OBJECT (bin, "loop dected in graph");
2011 g_warning ("loop detected in the graph of bin '%s'!!",
2012 GST_ELEMENT_NAME (bin));
2014 /* best unhandled element, schedule as next element */
2015 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2016 GST_ELEMENT_NAME (best));
2017 gst_object_ref (best);
2018 HASH_SET_DEGREE (bit, best, -1);
2021 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2022 /* no more unhandled elements, we are done */
2023 return GST_ITERATOR_DONE;
2026 /* everything added to the queue got reffed */
2027 *result = g_queue_pop_head (&bit->queue);
2030 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
2031 /* update degrees of linked elements */
2032 update_degree (GST_ELEMENT_CAST (*result), bit);
2034 return GST_ITERATOR_OK;
2037 /* clear queues, recalculate the degrees and restart. */
2039 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2041 GstBin *bin = bit->bin;
2043 GST_DEBUG_OBJECT (bin, "resync");
2045 clear_queue (&bit->queue);
2047 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2048 /* calc degrees, incrementing */
2050 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2051 /* for the rest of the function we decrement the degrees */
2055 /* clear queues, unref bin and free iterator. */
2057 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2059 GstBin *bin = bit->bin;
2061 GST_DEBUG_OBJECT (bin, "free");
2062 clear_queue (&bit->queue);
2063 g_hash_table_destroy (bit->hash);
2064 gst_object_unref (bin);
2068 /* should be called with the bin LOCK held */
2069 static GstIterator *
2070 gst_bin_sort_iterator_new (GstBin * bin)
2072 GstBinSortIterator *result;
2074 /* we don't need an ItemFunction because we ref the items in the _next
2076 result = (GstBinSortIterator *)
2077 gst_iterator_new (sizeof (GstBinSortIterator),
2079 GST_OBJECT_GET_LOCK (bin),
2080 &bin->priv->structure_cookie,
2081 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2082 (GstIteratorItemFunction) NULL,
2083 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2084 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2085 g_queue_init (&result->queue);
2086 result->hash = g_hash_table_new (NULL, NULL);
2087 gst_object_ref (bin);
2089 gst_bin_sort_iterator_resync (result);
2091 return (GstIterator *) result;
2095 * gst_bin_iterate_sorted:
2098 * Gets an iterator for the elements in this bin in topologically
2099 * sorted order. This means that the elements are returned from
2100 * the most downstream elements (sinks) to the sources.
2102 * This function is used internally to perform the state changes
2103 * of the bin elements and for clock selection.
2105 * Each element yielded by the iterator will have its refcount increased, so
2108 * MT safe. Caller owns returned value.
2110 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2113 gst_bin_iterate_sorted (GstBin * bin)
2115 GstIterator *result;
2117 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2119 GST_OBJECT_LOCK (bin);
2120 result = gst_bin_sort_iterator_new (bin);
2121 GST_OBJECT_UNLOCK (bin);
2126 static GstStateChangeReturn
2127 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2128 GstClockTime base_time, GstClockTime start_time, GstState current,
2131 GstStateChangeReturn ret;
2132 GstState pending, child_current, child_pending;
2136 GST_STATE_LOCK (element);
2138 GST_OBJECT_LOCK (element);
2139 /* set base_time and start time on child */
2140 GST_ELEMENT_START_TIME (element) = start_time;
2141 element->base_time = base_time;
2142 /* peel off the locked flag */
2143 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2144 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2145 ret = GST_STATE_RETURN (element);
2146 child_current = GST_STATE (element);
2147 child_pending = GST_STATE_PENDING (element);
2148 GST_OBJECT_UNLOCK (element);
2150 /* skip locked elements */
2151 if (G_UNLIKELY (locked))
2154 /* if the element was no preroll, just start changing the state regardless
2155 * if it had async elements (in the case of a bin) because they won't preroll
2157 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2158 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2162 GST_OBJECT_LOCK (bin);
2163 pending = GST_STATE_PENDING (bin);
2165 /* Try not to change the state of elements that are already in the state we're
2167 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2168 (child_pending == GST_STATE_VOID_PENDING &&
2169 ((pending > child_current && next > child_current) ||
2170 (pending < child_current && next < child_current)))))
2173 /* the element was busy with an upwards async state change, we must wait for
2174 * an ASYNC_DONE message before we attemp to change the state. */
2176 find_message (bin, GST_OBJECT_CAST (element),
2177 GST_MESSAGE_ASYNC_START))) {
2178 #ifndef GST_DISABLE_GST_DEBUG
2179 GstMessage *message = GST_MESSAGE_CAST (found->data);
2181 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2182 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2184 /* only wait for upward state changes */
2185 if (next > current) {
2186 /* We found an async element check if we can force its state to change or
2187 * if we have to wait for it to preroll. */
2188 if (G_UNLIKELY (!enable_latency)) {
2189 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2190 "\tto preroll in order to perform correct latency calculations.\n"
2191 "\tPlease verify that the application continues to work correctly by\n"
2192 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2193 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2200 GST_OBJECT_UNLOCK (bin);
2203 GST_DEBUG_OBJECT (bin,
2204 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2205 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2206 GST_TIME_ARGS (base_time));
2209 ret = gst_element_set_state (element, next);
2211 GST_STATE_UNLOCK (element);
2217 GST_DEBUG_OBJECT (element,
2218 "element is locked, return previous return %s",
2219 gst_element_state_change_return_get_name (ret));
2220 GST_STATE_UNLOCK (element);
2225 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2226 GST_OBJECT_UNLOCK (bin);
2227 GST_STATE_UNLOCK (element);
2228 return GST_STATE_CHANGE_ASYNC;
2232 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2233 "skipping transition from %s to %s, since bin pending"
2234 " is %s : last change state return follows",
2235 gst_element_state_get_name (child_current),
2236 gst_element_state_get_name (next),
2237 gst_element_state_get_name (pending));
2238 GST_OBJECT_UNLOCK (bin);
2239 GST_STATE_UNLOCK (element);
2244 /* gst_iterator_fold functions for pads_activate
2245 * Stop the iterator if activating one pad failed. */
2247 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2249 gboolean cont = TRUE;
2251 if (!(cont = gst_pad_set_active (pad, *active)))
2252 g_value_set_boolean (ret, FALSE);
2254 gst_pad_set_caps (pad, NULL);
2256 /* unref the object that was reffed for us by _fold */
2257 gst_object_unref (pad);
2261 /* returns false on error or early cutout of the fold, true if all
2262 * pads in @iter were (de)activated successfully. */
2264 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2266 GstIteratorResult ires;
2269 /* no need to unset this later, it's just a boolean */
2270 g_value_init (&ret, G_TYPE_BOOLEAN);
2271 g_value_set_boolean (&ret, TRUE);
2274 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2277 case GST_ITERATOR_RESYNC:
2278 /* need to reset the result again */
2279 g_value_set_boolean (&ret, TRUE);
2280 gst_iterator_resync (iter);
2282 case GST_ITERATOR_DONE:
2283 /* all pads iterated, return collected value */
2286 /* iterator returned _ERROR or premature end with _OK,
2287 * mark an error and exit */
2288 g_value_set_boolean (&ret, FALSE);
2293 /* return collected value */
2294 return g_value_get_boolean (&ret);
2297 /* is called with STATE_LOCK
2300 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2305 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2307 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2308 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2309 gst_iterator_free (iter);
2310 if (G_UNLIKELY (!fold_ok))
2313 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2320 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2326 * gst_bin_recalculate_latency:
2329 * Query @bin for the current latency using and reconfigures this latency to all the
2330 * elements with a LATENCY event.
2332 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2333 * is posted on the bus.
2335 * This function simply emits the 'do-latency' signal so any custom latency
2336 * calculations will be performed.
2338 * Returns: %TRUE if the latency could be queried and reconfigured.
2343 gst_bin_recalculate_latency (GstBin * bin)
2347 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2348 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2354 gst_bin_do_latency_func (GstBin * bin)
2357 GstElement *element;
2358 GstClockTime min_latency, max_latency;
2361 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2363 element = GST_ELEMENT_CAST (bin);
2365 GST_DEBUG_OBJECT (element, "querying latency");
2367 query = gst_query_new_latency ();
2368 if ((res = gst_element_query (element, query))) {
2371 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2373 GST_DEBUG_OBJECT (element,
2374 "got min latency %" GST_TIME_FORMAT ", max latency %"
2375 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2376 GST_TIME_ARGS (max_latency), live);
2378 if (max_latency < min_latency) {
2379 /* this is an impossible situation, some parts of the pipeline might not
2380 * work correctly. We post a warning for now. */
2381 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2382 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2383 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2384 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2387 /* configure latency on elements */
2388 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2390 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2391 GST_TIME_ARGS (min_latency));
2393 GST_WARNING_OBJECT (element,
2394 "did not really configure latency of %" GST_TIME_FORMAT,
2395 GST_TIME_ARGS (min_latency));
2398 /* this is not a real problem, we just don't configure any latency. */
2399 GST_WARNING_OBJECT (element, "failed to query latency");
2401 gst_query_unref (query);
2407 gst_bin_state_changed (GstElement * element, GstState oldstate,
2408 GstState newstate, GstState pending)
2410 GstElementClass *pklass = (GstElementClass *) parent_class;
2412 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2413 bin_do_eos (GST_BIN_CAST (element));
2415 if (pklass->state_changed)
2416 pklass->state_changed (element, oldstate, newstate, pending);
2419 static GstStateChangeReturn
2420 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2423 GstStateChangeReturn ret;
2424 GstState current, next;
2425 gboolean have_async;
2426 gboolean have_no_preroll;
2427 GstClockTime base_time, start_time;
2431 /* we don't need to take the STATE_LOCK, it is already taken */
2432 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2433 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2435 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2436 "changing state of children from %s to %s",
2437 gst_element_state_get_name (current), gst_element_state_get_name (next));
2439 bin = GST_BIN_CAST (element);
2442 case GST_STATE_PLAYING:
2446 GST_OBJECT_LOCK (bin);
2447 toplevel = BIN_IS_TOPLEVEL (bin);
2448 GST_OBJECT_UNLOCK (bin);
2451 gst_bin_recalculate_latency (bin);
2454 case GST_STATE_PAUSED:
2455 /* Clear EOS list on next PAUSED */
2456 GST_OBJECT_LOCK (bin);
2457 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2458 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2459 bin->priv->posted_eos = FALSE;
2460 GST_OBJECT_UNLOCK (bin);
2461 if (current == GST_STATE_READY)
2462 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2463 goto activate_failure;
2465 case GST_STATE_READY:
2466 /* Clear message list on next READY */
2467 GST_OBJECT_LOCK (bin);
2468 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2469 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2470 GST_OBJECT_UNLOCK (bin);
2471 if (current == GST_STATE_PAUSED)
2472 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2473 goto activate_failure;
2475 case GST_STATE_NULL:
2476 if (current == GST_STATE_READY)
2477 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2478 goto activate_failure;
2484 /* this flag is used to make the async state changes return immediately. We
2485 * don't want them to interfere with this state change */
2486 GST_OBJECT_LOCK (bin);
2487 bin->polling = TRUE;
2488 GST_OBJECT_UNLOCK (bin);
2490 /* iterate in state change order */
2491 it = gst_bin_iterate_sorted (bin);
2493 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2494 * Note how we don't reset this value when a resync happens, the reason being
2495 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2496 * even after a resync when the async element is gone */
2500 /* take base_time */
2501 base_time = gst_element_get_base_time (element);
2502 start_time = gst_element_get_start_time (element);
2504 have_no_preroll = FALSE;
2510 switch (gst_iterator_next (it, &data)) {
2511 case GST_ITERATOR_OK:
2515 child = GST_ELEMENT_CAST (data);
2517 /* set state and base_time now */
2518 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2522 case GST_STATE_CHANGE_SUCCESS:
2523 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2524 "child '%s' changed state to %d(%s) successfully",
2525 GST_ELEMENT_NAME (child), next,
2526 gst_element_state_get_name (next));
2528 case GST_STATE_CHANGE_ASYNC:
2530 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2531 "child '%s' is changing state asynchronously to %s",
2532 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2536 case GST_STATE_CHANGE_FAILURE:{
2539 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2540 "child '%s' failed to go to state %d(%s)",
2541 GST_ELEMENT_NAME (child),
2542 next, gst_element_state_get_name (next));
2544 /* Only fail if the child is still inside
2545 * this bin. It might've been removed already
2546 * because of the error by the bin subclass
2547 * to ignore the error. */
2548 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2549 if (parent == GST_OBJECT_CAST (element)) {
2550 /* element is still in bin, really error now */
2551 gst_object_unref (child);
2552 gst_object_unref (parent);
2555 /* child removed from bin, let the resync code redo the state
2557 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2558 "child '%s' was removed from the bin",
2559 GST_ELEMENT_NAME (child));
2562 gst_object_unref (parent);
2566 case GST_STATE_CHANGE_NO_PREROLL:
2567 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2568 "child '%s' changed state to %d(%s) successfully without preroll",
2569 GST_ELEMENT_NAME (child), next,
2570 gst_element_state_get_name (next));
2571 have_no_preroll = TRUE;
2574 g_assert_not_reached ();
2577 gst_object_unref (child);
2580 case GST_ITERATOR_RESYNC:
2581 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2582 gst_iterator_resync (it);
2585 case GST_ITERATOR_DONE:
2586 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2592 ret = parent_class->change_state (element, transition);
2593 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2596 if (have_no_preroll) {
2597 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2598 "we have NO_PREROLL elements %s -> NO_PREROLL",
2599 gst_element_state_change_return_get_name (ret));
2600 ret = GST_STATE_CHANGE_NO_PREROLL;
2601 } else if (have_async) {
2602 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2603 "we have ASYNC elements %s -> ASYNC",
2604 gst_element_state_change_return_get_name (ret));
2605 ret = GST_STATE_CHANGE_ASYNC;
2609 gst_iterator_free (it);
2611 GST_OBJECT_LOCK (bin);
2612 bin->polling = FALSE;
2613 /* it's possible that we did not get ASYNC from the children while the bin is
2614 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2615 * itself as the source. In that case we still want to check if the state
2616 * change completed. */
2617 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2618 /* no element returned ASYNC and there are no pending async_done messages,
2619 * we can just complete. */
2620 GST_DEBUG_OBJECT (bin, "no async elements");
2623 /* when we get here an ASYNC element was found */
2624 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2625 /* we ignore ASYNC state changes when we go to READY or NULL */
2626 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2627 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2631 GST_DEBUG_OBJECT (bin, "check async elements");
2632 /* check if all elements managed to commit their state already */
2633 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2634 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2635 * all the elements commited their state while we were doing the state
2636 * change. We will still return ASYNC for consistency but we commit the
2637 * state already so that a _get_state() will return immediately. */
2638 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2640 GST_DEBUG_OBJECT (bin, "async elements commited");
2641 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2645 bin->priv->pending_async_done = FALSE;
2646 GST_OBJECT_UNLOCK (bin);
2648 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2649 "done changing bin's state from %s to %s, now in %s, ret %s",
2650 gst_element_state_get_name (current),
2651 gst_element_state_get_name (next),
2652 gst_element_state_get_name (GST_STATE (element)),
2653 gst_element_state_change_return_get_name (ret));
2660 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2661 "failure (de)activating src pads");
2662 return GST_STATE_CHANGE_FAILURE;
2667 * This function is a utility event handler for seek events.
2668 * It will send the event to all sinks or sources depending on the
2671 * Applications are free to override this behaviour and
2672 * implement their own seek handler, but this will work for
2673 * pretty much all cases in practice.
2676 gst_bin_send_event (GstElement * element, GstEvent * event)
2678 GstBin *bin = GST_BIN_CAST (element);
2680 gboolean res = TRUE;
2681 gboolean done = FALSE;
2683 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2684 iter = gst_bin_iterate_sources (bin);
2685 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2686 GST_EVENT_TYPE_NAME (event));
2688 iter = gst_bin_iterate_sinks (bin);
2689 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2690 GST_EVENT_TYPE_NAME (event));
2696 switch (gst_iterator_next (iter, &data)) {
2697 case GST_ITERATOR_OK:
2701 gst_event_ref (event);
2702 child = GST_ELEMENT_CAST (data);
2703 res &= gst_element_send_event (child, event);
2704 GST_LOG_OBJECT (child, "After handling %s event: %d",
2705 GST_EVENT_TYPE_NAME (event), res);
2706 gst_object_unref (child);
2709 case GST_ITERATOR_RESYNC:
2710 gst_iterator_resync (iter);
2713 case GST_ITERATOR_DONE:
2716 case GST_ITERATOR_ERROR:
2717 g_assert_not_reached ();
2721 gst_iterator_free (iter);
2722 gst_event_unref (event);
2727 /* this is the function called by the threadpool. When async elements commit
2728 * their state, this function will attempt to bring the bin to the next state.
2731 gst_bin_continue_func (BinContinueData * data)
2734 GstState current, next, pending;
2735 GstStateChange transition;
2738 pending = data->pending;
2740 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2741 GST_STATE_LOCK (bin);
2743 GST_DEBUG_OBJECT (bin, "doing state continue");
2744 GST_OBJECT_LOCK (bin);
2746 /* if a new state change happened after this thread was scheduled, we return
2748 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2751 current = GST_STATE (bin);
2752 next = GST_STATE_GET_NEXT (current, pending);
2753 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2755 GST_STATE_NEXT (bin) = next;
2756 GST_STATE_PENDING (bin) = pending;
2758 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2759 GST_OBJECT_UNLOCK (bin);
2761 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2762 "continue state change %s to %s, final %s",
2763 gst_element_state_get_name (current),
2764 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2766 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2768 GST_STATE_UNLOCK (bin);
2769 GST_DEBUG_OBJECT (bin, "state continue done");
2771 gst_object_unref (bin);
2772 g_slice_free (BinContinueData, data);
2777 GST_OBJECT_UNLOCK (bin);
2778 GST_STATE_UNLOCK (bin);
2779 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2780 gst_object_unref (bin);
2781 g_slice_free (BinContinueData, data);
2786 static GstBusSyncReply
2787 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2789 GstBinClass *bclass;
2791 bclass = GST_BIN_GET_CLASS (bin);
2792 if (bclass->handle_message)
2793 bclass->handle_message (bin, message);
2795 gst_message_unref (message);
2797 return GST_BUS_DROP;
2801 bin_push_state_continue (BinContinueData * data)
2808 klass = GST_BIN_GET_CLASS (bin);
2810 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2811 g_thread_pool_push (klass->pool, data, NULL);
2814 /* an element started an async state change, if we were not busy with a state
2815 * change, we perform a lost state.
2816 * This function is called with the OBJECT lock.
2819 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2821 GstState old_state, new_state;
2823 GstMessage *amessage = NULL;
2825 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2828 /* get our toplevel state */
2829 toplevel = BIN_IS_TOPLEVEL (bin);
2831 /* prepare an ASYNC_START message, we always post the start message even if we
2832 * are busy with a state change or when we are NO_PREROLL. */
2834 /* non toplevel bin, prepare async-start for the parent */
2836 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2838 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2841 /* async starts are ignored when we are NO_PREROLL */
2842 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2843 goto was_no_preroll;
2845 old_state = GST_STATE (bin);
2847 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2848 * PLAYING after optionally redistributing the base_time. */
2849 if (old_state > GST_STATE_PAUSED)
2850 new_state = GST_STATE_PAUSED;
2852 new_state = old_state;
2854 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2855 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2856 gst_element_state_get_name (new_state));
2858 GST_STATE (bin) = new_state;
2859 GST_STATE_NEXT (bin) = new_state;
2860 GST_STATE_PENDING (bin) = new_state;
2861 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2862 GST_OBJECT_UNLOCK (bin);
2865 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2870 /* post our ASYNC_START. */
2871 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2872 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2874 GST_OBJECT_LOCK (bin);
2880 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2885 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2886 GST_OBJECT_UNLOCK (bin);
2891 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2892 GST_OBJECT_UNLOCK (bin);
2897 /* this function is called when there are no more async elements in the bin. We
2898 * post a state changed message and an ASYNC_DONE message.
2899 * This function is called with the OBJECT lock.
2902 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2903 gboolean flag_pending)
2905 GstState current, pending, target;
2906 GstStateChangeReturn old_ret;
2907 GstState old_state, old_next;
2908 gboolean toplevel, state_changed = FALSE;
2909 GstMessage *amessage = NULL;
2910 BinContinueData *cont = NULL;
2912 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2915 pending = GST_STATE_PENDING (bin);
2920 /* check if there is something to commit */
2921 if (pending == GST_STATE_VOID_PENDING)
2922 goto nothing_pending;
2924 old_ret = GST_STATE_RETURN (bin);
2925 GST_STATE_RETURN (bin) = ret;
2927 /* move to the next target state */
2928 target = GST_STATE_TARGET (bin);
2929 pending = GST_STATE_PENDING (bin) = target;
2931 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2933 old_state = GST_STATE (bin);
2934 /* this is the state we should go to next */
2935 old_next = GST_STATE_NEXT (bin);
2937 if (old_next != GST_STATE_PLAYING) {
2938 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2939 "committing state from %s to %s, old pending %s",
2940 gst_element_state_get_name (old_state),
2941 gst_element_state_get_name (old_next),
2942 gst_element_state_get_name (pending));
2944 /* update current state */
2945 current = GST_STATE (bin) = old_next;
2947 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2948 "setting state from %s to %s, pending %s",
2949 gst_element_state_get_name (old_state),
2950 gst_element_state_get_name (old_state),
2951 gst_element_state_get_name (pending));
2952 current = old_state;
2955 /* get our toplevel state */
2956 toplevel = BIN_IS_TOPLEVEL (bin);
2958 /* see if we reached the final state. If we are not toplevel, we also have to
2959 * stop here, the parent will continue our state. */
2960 if ((pending == current) || !toplevel) {
2961 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2962 "completed state change, pending VOID");
2964 /* mark VOID pending */
2965 pending = GST_STATE_VOID_PENDING;
2966 GST_STATE_PENDING (bin) = pending;
2967 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2969 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2970 "continue state change, pending %s",
2971 gst_element_state_get_name (pending));
2973 cont = g_slice_new (BinContinueData);
2975 /* ref to the bin */
2976 cont->bin = gst_object_ref (bin);
2977 /* cookie to detect concurrent state change */
2978 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2979 /* pending target state */
2980 cont->pending = pending;
2982 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2983 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2986 if (old_next != GST_STATE_PLAYING) {
2987 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2988 state_changed = TRUE;
2991 GST_OBJECT_UNLOCK (bin);
2993 if (state_changed) {
2994 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
2998 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2999 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3000 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3003 GST_OBJECT_LOCK (bin);
3005 /* toplevel, start continue state */
3006 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3007 bin_push_state_continue (cont);
3009 GST_DEBUG_OBJECT (bin, "state change complete");
3010 GST_STATE_BROADCAST (bin);
3016 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3021 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3022 /* if we were busy with a state change and we are requested to flag a
3023 * pending async done, we do so here */
3025 bin->priv->pending_async_done = TRUE;
3030 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3036 bin_do_eos (GstBin * bin)
3041 GST_OBJECT_LOCK (bin);
3042 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3043 * we forward the EOS message to the parent bin or application
3045 eos = GST_STATE (bin) == GST_STATE_PLAYING
3046 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3047 && is_eos (bin, &seqnum);
3048 GST_OBJECT_UNLOCK (bin);
3051 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3053 GstMessage *tmessage;
3055 /* Clear out any further messages, and reset posted_eos so we can
3056 detect any new EOS that happens (eg, after a seek). Since all
3057 sinks have now posted an EOS, there will be no further EOS events
3058 seen unless there is a new logical EOS */
3059 GST_OBJECT_LOCK (bin);
3060 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
3061 bin->priv->posted_eos = FALSE;
3062 GST_OBJECT_UNLOCK (bin);
3064 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3065 gst_message_set_seqnum (tmessage, seqnum);
3066 GST_DEBUG_OBJECT (bin,
3067 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3068 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3072 /* must be called with the object lock. This function releases the lock to post
3075 bin_do_message_forward (GstBin * bin, GstMessage * message)
3077 if (bin->priv->message_forward) {
3078 GstMessage *forwarded;
3080 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3081 GST_MESSAGE_TYPE_NAME (message));
3082 GST_OBJECT_UNLOCK (bin);
3084 /* we need to convert these messages to element messages so that our parent
3085 * bin can easily ignore them and so that the application can easily
3086 * distinguish between the internally forwarded and the real messages. */
3087 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3088 gst_structure_new ("GstBinForwarded",
3089 "message", GST_TYPE_MESSAGE, message, NULL));
3091 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3093 GST_OBJECT_LOCK (bin);
3097 /* handle child messages:
3099 * This method is called synchronously when a child posts a message on
3102 * GST_MESSAGE_EOS: This message is only posted by sinks
3103 * in the PLAYING state. If all sinks posted the EOS message, post
3106 * GST_MESSAGE_STATE_DIRTY: Deprecated
3108 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3109 * element posts segment_start twice, only the last message is kept.
3111 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3112 * with the segment_done message. If there are no more segment_start
3113 * messages, post segment_done message upwards.
3115 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3116 * Whenever someone performs a duration query on the bin, we store the
3117 * result so we can answer it quicker the next time. Any element that
3118 * changes its duration marks our cached values invalid.
3119 * This message is also posted upwards. This is currently disabled
3120 * because too many elements don't post DURATION messages when the
3123 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3124 * can no longer provide a clock. The default bin behaviour is to
3125 * check if the lost clock was the one provided by the bin. If so and
3126 * we are currently in the PLAYING state, we forward the message to
3128 * This message is also generated when we remove a clock provider from
3129 * a bin. If this message is received by the application, it should
3130 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3131 * and a new base_time distribution.
3133 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3134 * can provide a clock. This mostly happens when we add a new clock
3135 * provider to the bin. The default behaviour of the bin is to mark the
3136 * currently selected clock as dirty, which will perform a clock
3137 * recalculation the next time we are asked to provide a clock.
3138 * This message is never sent to the application but is forwarded to
3141 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3142 * the state of the element and the fact that the element will need a
3143 * new base_time. This message is not forwarded to the application.
3145 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3146 * element when it posted ASYNC_START. If all elements are done, post a
3147 * ASYNC_DONE message to the parent.
3149 * OTHER: post upwards.
3152 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3155 GstMessageType type;
3156 GstMessage *tmessage;
3159 src = GST_MESSAGE_SRC (message);
3160 type = GST_MESSAGE_TYPE (message);
3162 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3163 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3164 GST_MESSAGE_TYPE_NAME (message));
3167 case GST_MESSAGE_ERROR:
3169 GST_OBJECT_LOCK (bin);
3171 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3172 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3173 GST_STATE_BROADCAST (bin);
3174 GST_OBJECT_UNLOCK (bin);
3178 case GST_MESSAGE_EOS:
3181 /* collect all eos messages from the children */
3182 GST_OBJECT_LOCK (bin);
3183 bin_do_message_forward (bin, message);
3184 /* ref message for future use */
3185 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3186 GST_OBJECT_UNLOCK (bin);
3191 case GST_MESSAGE_STATE_DIRTY:
3193 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3196 gst_message_unref (message);
3199 case GST_MESSAGE_SEGMENT_START:{
3200 gboolean post = FALSE;
3204 gst_message_parse_segment_start (message, &format, &position);
3205 seqnum = gst_message_get_seqnum (message);
3207 GST_OBJECT_LOCK (bin);
3208 bin_do_message_forward (bin, message);
3209 /* if this is the first segment-start, post to parent but not to the
3211 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3212 (GST_OBJECT_PARENT (bin) != NULL)) {
3215 /* replace any previous segment_start message from this source
3216 * with the new segment start message */
3217 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3218 GST_OBJECT_UNLOCK (bin);
3220 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3222 gst_message_set_seqnum (tmessage, seqnum);
3224 /* post segment start with initial format and position. */
3225 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3227 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3231 case GST_MESSAGE_SEGMENT_DONE:
3233 gboolean post = FALSE;
3237 gst_message_parse_segment_done (message, &format, &position);
3238 seqnum = gst_message_get_seqnum (message);
3240 GST_OBJECT_LOCK (bin);
3241 bin_do_message_forward (bin, message);
3242 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3243 /* if there are no more segment_start messages, everybody posted
3244 * a segment_done and we can post one on the bus. */
3246 /* we don't care who still has a pending segment start */
3247 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3250 /* remove all old segment_done messages */
3251 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3253 GST_OBJECT_UNLOCK (bin);
3255 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3257 gst_message_set_seqnum (tmessage, seqnum);
3259 /* post segment done with latest format and position. */
3260 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3262 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3266 case GST_MESSAGE_DURATION:
3268 /* remove all cached duration messages, next time somebody asks
3269 * for duration, we will recalculate. */
3270 GST_OBJECT_LOCK (bin);
3271 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3272 GST_OBJECT_UNLOCK (bin);
3275 case GST_MESSAGE_CLOCK_LOST:
3277 GstClock **provided_clock_p;
3278 GstElement **clock_provider_p;
3279 gboolean playing, provided, forward;
3282 gst_message_parse_clock_lost (message, &clock);
3284 GST_OBJECT_LOCK (bin);
3285 bin->clock_dirty = TRUE;
3286 /* if we lost the clock that we provided, post to parent but
3287 * only if we are PLAYING. */
3288 provided = (clock == bin->provided_clock);
3289 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3290 forward = playing & provided;
3292 GST_DEBUG_OBJECT (bin,
3293 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3294 bin->provided_clock, bin->clock_provider);
3295 provided_clock_p = &bin->provided_clock;
3296 clock_provider_p = &bin->clock_provider;
3297 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3298 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3300 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3301 provided, playing, forward);
3302 GST_OBJECT_UNLOCK (bin);
3308 gst_message_unref (message);
3311 case GST_MESSAGE_CLOCK_PROVIDE:
3315 GST_OBJECT_LOCK (bin);
3316 bin->clock_dirty = TRUE;
3317 /* a new clock is available, post to parent but not
3318 * to the application */
3319 forward = GST_OBJECT_PARENT (bin) != NULL;
3320 GST_OBJECT_UNLOCK (bin);
3326 gst_message_unref (message);
3329 case GST_MESSAGE_ASYNC_START:
3331 gboolean new_base_time;
3334 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3335 src ? GST_OBJECT_NAME (src) : "(NULL)");
3337 gst_message_parse_async_start (message, &new_base_time);
3339 GST_OBJECT_LOCK (bin);
3340 bin_do_message_forward (bin, message);
3342 /* we ignore the message if we are going to <= READY */
3343 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3344 goto ignore_start_message;
3346 /* takes ownership of the message */
3347 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3349 bin_handle_async_start (bin, new_base_time);
3350 GST_OBJECT_UNLOCK (bin);
3353 ignore_start_message:
3355 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3356 gst_element_state_get_name (target));
3357 GST_OBJECT_UNLOCK (bin);
3358 gst_message_unref (message);
3362 case GST_MESSAGE_ASYNC_DONE:
3366 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3367 src ? GST_OBJECT_NAME (src) : "(NULL)");
3369 GST_OBJECT_LOCK (bin);
3370 bin_do_message_forward (bin, message);
3372 /* ignore messages if we are shutting down */
3373 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3374 goto ignore_done_message;
3376 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3377 /* if there are no more ASYNC_START messages, everybody posted
3378 * a ASYNC_DONE and we can post one on the bus. When checking, we
3379 * don't care who still has a pending ASYNC_START */
3380 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3381 /* nothing found, remove all old ASYNC_DONE messages */
3382 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3384 GST_DEBUG_OBJECT (bin, "async elements commited");
3385 /* when we get an async done message when a state change was busy, we
3386 * need to set the pending_done flag so that at the end of the state
3387 * change we can see if we need to verify pending async elements, hence
3388 * the TRUE argument here. */
3389 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3391 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3393 GST_OBJECT_UNLOCK (bin);
3396 ignore_done_message:
3398 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3399 gst_element_state_get_name (target));
3400 GST_OBJECT_UNLOCK (bin);
3401 gst_message_unref (message);
3405 case GST_MESSAGE_STRUCTURE_CHANGE:
3409 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3411 GST_OBJECT_LOCK (bin);
3413 /* while the pad is busy, avoid following it when doing state changes.
3414 * Don't update the cookie yet, we will do that after the structure
3415 * change finished and we are ready to inspect the new updated
3417 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3420 /* a pad link/unlink ended, signal the state change iterator that we
3421 * need to resync by updating the structure_cookie. */
3422 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3423 GST_MESSAGE_STRUCTURE_CHANGE);
3424 bin->priv->structure_cookie++;
3426 GST_OBJECT_UNLOCK (bin);
3429 gst_message_unref (message);
3440 /* Send all other messages upward */
3441 GST_DEBUG_OBJECT (bin, "posting message upward");
3442 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3447 /* generic struct passed to all query fold methods */
3456 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3457 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3459 /* for duration/position we collect all durations/positions and take
3460 * the MAX of all valid results */
3462 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3470 bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
3472 if (gst_element_query (item, fold->query)) {
3475 g_value_set_boolean (ret, TRUE);
3477 gst_query_parse_duration (fold->query, NULL, &duration);
3479 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3481 if (duration > fold->max)
3482 fold->max = duration;
3485 gst_object_unref (item);
3490 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3494 gst_query_parse_duration (fold->query, &format, NULL);
3495 /* store max in query result */
3496 gst_query_set_duration (fold->query, format, fold->max);
3498 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3500 #ifdef DURATION_CACHING
3502 GST_OBJECT_LOCK (bin);
3503 bin->messages = g_list_prepend (bin->messages,
3504 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3505 GST_OBJECT_UNLOCK (bin);
3510 bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
3512 if (gst_element_query (item, fold->query)) {
3515 g_value_set_boolean (ret, TRUE);
3517 gst_query_parse_position (fold->query, NULL, &position);
3519 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3521 if (position > fold->max)
3522 fold->max = position;
3525 gst_object_unref (item);
3530 bin_query_position_done (GstBin * bin, QueryFold * fold)
3534 gst_query_parse_position (fold->query, &format, NULL);
3535 /* store max in query result */
3536 gst_query_set_position (fold->query, format, fold->max);
3538 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3542 bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
3544 if (gst_element_query (item, fold->query)) {
3545 GstClockTime min, max;
3548 gst_query_parse_latency (fold->query, &live, &min, &max);
3550 GST_DEBUG_OBJECT (item,
3551 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3552 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3554 /* for the combined latency we collect the MAX of all min latencies and
3555 * the MIN of all max latencies */
3557 if (min > fold->min)
3559 if (fold->max == -1)
3561 else if (max < fold->max)
3563 if (fold->live == FALSE)
3567 g_value_set_boolean (ret, FALSE);
3568 GST_DEBUG_OBJECT (item, "failed query");
3571 gst_object_unref (item);
3576 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3578 /* store max in query result */
3579 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3581 GST_DEBUG_OBJECT (bin,
3582 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3583 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3587 /* generic fold, return first valid result */
3589 bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
3593 if ((res = gst_element_query (item, fold->query))) {
3594 g_value_set_boolean (ret, TRUE);
3595 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3598 gst_object_unref (item);
3600 /* and stop as soon as we have a valid result */
3605 gst_bin_query (GstElement * element, GstQuery * query)
3607 GstBin *bin = GST_BIN_CAST (element);
3609 gboolean res = FALSE;
3610 GstIteratorFoldFunction fold_func;
3611 QueryInitFunction fold_init = NULL;
3612 QueryDoneFunction fold_done = NULL;
3613 QueryFold fold_data;
3616 switch (GST_QUERY_TYPE (query)) {
3617 case GST_QUERY_DURATION:
3619 #ifdef DURATION_CACHING
3623 gst_query_parse_duration (query, &qformat, NULL);
3625 /* find cached duration query */
3626 GST_OBJECT_LOCK (bin);
3627 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3628 GstMessage *message = (GstMessage *) cached->data;
3630 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3631 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3635 gst_message_parse_duration (message, &format, &duration);
3637 /* if cached same format, copy duration in query result */
3638 if (format == qformat) {
3639 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3641 GST_OBJECT_UNLOCK (bin);
3643 gst_query_set_duration (query, qformat, duration);
3649 GST_OBJECT_UNLOCK (bin);
3651 /* no cached value found, iterate and collect durations */
3652 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3653 fold_init = bin_query_min_max_init;
3654 fold_done = bin_query_duration_done;
3657 case GST_QUERY_POSITION:
3659 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3660 fold_init = bin_query_min_max_init;
3661 fold_done = bin_query_position_done;
3664 case GST_QUERY_LATENCY:
3666 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3667 fold_init = bin_query_min_max_init;
3668 fold_done = bin_query_latency_done;
3673 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3677 fold_data.query = query;
3679 /* set the result of the query to FALSE initially */
3680 g_value_init (&ret, G_TYPE_BOOLEAN);
3681 g_value_set_boolean (&ret, res);
3683 iter = gst_bin_iterate_sinks (bin);
3684 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3685 query, GST_QUERY_TYPE_NAME (query));
3688 fold_init (bin, &fold_data);
3691 GstIteratorResult ires;
3693 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3696 case GST_ITERATOR_RESYNC:
3697 gst_iterator_resync (iter);
3699 fold_init (bin, &fold_data);
3700 g_value_set_boolean (&ret, res);
3702 case GST_ITERATOR_OK:
3703 case GST_ITERATOR_DONE:
3704 res = g_value_get_boolean (&ret);
3705 if (fold_done != NULL && res)
3706 fold_done (bin, &fold_data);
3714 gst_iterator_free (iter);
3716 #ifdef DURATION_CACHING
3719 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3725 compare_name (GstElement * element, const gchar * name)
3729 GST_OBJECT_LOCK (element);
3730 eq = strcmp (GST_ELEMENT_NAME (element), name);
3731 GST_OBJECT_UNLOCK (element);
3734 gst_object_unref (element);
3740 * gst_bin_get_by_name:
3742 * @name: the element name to search for
3744 * Gets the element with the given name from a bin. This
3745 * function recurses into child bins.
3747 * Returns NULL if no element with the given name is found in the bin.
3749 * MT safe. Caller owns returned reference.
3751 * Returns: (transfer full): the #GstElement with the given name, or NULL
3754 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3756 GstIterator *children;
3759 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3761 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3762 GST_ELEMENT_NAME (bin), name);
3764 children = gst_bin_iterate_recurse (bin);
3765 result = gst_iterator_find_custom (children,
3766 (GCompareFunc) compare_name, (gpointer) name);
3767 gst_iterator_free (children);
3769 return GST_ELEMENT_CAST (result);
3773 * gst_bin_get_by_name_recurse_up:
3775 * @name: the element name to search for
3777 * Gets the element with the given name from this bin. If the
3778 * element is not found, a recursion is performed on the parent bin.
3781 * - no element with the given name is found in the bin
3783 * MT safe. Caller owns returned reference.
3785 * Returns: (transfer full): the #GstElement with the given name, or NULL
3788 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3792 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3793 g_return_val_if_fail (name != NULL, NULL);
3795 result = gst_bin_get_by_name (bin, name);
3800 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3802 if (GST_IS_BIN (parent)) {
3803 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3805 gst_object_unref (parent);
3813 compare_interface (GstElement * element, gpointer interface)
3815 GType interface_type = (GType) interface;
3818 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3821 /* we did not find the element, need to release the ref
3822 * added by the iterator */
3823 gst_object_unref (element);
3830 * gst_bin_get_by_interface:
3832 * @iface: the #GType of an interface
3834 * Looks for an element inside the bin that implements the given
3835 * interface. If such an element is found, it returns the element.
3836 * You can cast this element to the given interface afterwards. If you want
3837 * all elements that implement the interface, use
3838 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3840 * MT safe. Caller owns returned reference.
3842 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3845 gst_bin_get_by_interface (GstBin * bin, GType iface)
3847 GstIterator *children;
3850 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3851 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3853 children = gst_bin_iterate_recurse (bin);
3854 result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3856 gst_iterator_free (children);
3858 return GST_ELEMENT_CAST (result);
3862 * gst_bin_iterate_all_by_interface:
3864 * @iface: the #GType of an interface
3866 * Looks for all elements inside the bin that implements the given
3867 * interface. You can safely cast all returned elements to the given interface.
3868 * The function recurses inside child bins. The iterator will yield a series
3869 * of #GstElement that should be unreffed after use.
3871 * Each element yielded by the iterator will have its refcount increased, so
3874 * MT safe. Caller owns returned value.
3876 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3877 * in the bin implementing the given interface, or NULL
3880 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3882 GstIterator *children;
3883 GstIterator *result;
3885 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3886 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3888 children = gst_bin_iterate_recurse (bin);
3889 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3895 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
3897 gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
3899 GstBin *bin = GST_BIN_CAST (object);
3900 xmlNodePtr childlist, elementnode;
3904 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
3905 GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
3907 childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
3909 GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
3910 GST_ELEMENT_NAME (bin), bin->numchildren);
3912 children = g_list_last (bin->children);
3914 child = GST_ELEMENT_CAST (children->data);
3915 elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
3916 gst_object_save_thyself (GST_OBJECT (child), elementnode);
3917 children = g_list_previous (children);
3923 gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
3925 GstBin *bin = GST_BIN_CAST (object);
3926 xmlNodePtr field = self->xmlChildrenNode;
3927 xmlNodePtr childlist;
3930 if (!strcmp ((char *) field->name, "children")) {
3931 GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
3932 GST_ELEMENT_NAME (object));
3933 childlist = field->xmlChildrenNode;
3935 if (!strcmp ((char *) childlist->name, "element")) {
3936 /* gst_xml_make_element will gst_bin_add() the element to ourself */
3937 gst_xml_make_element (childlist, GST_OBJECT (bin));
3939 childlist = childlist->next;
3943 field = field->next;
3945 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
3946 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
3948 #endif /* GST_DISABLE_LOADSAVE */