3 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
4 * 2004 Wim Taymans <wim.taymans@gmail.com>
6 * gstbin.c: GstBin container object and support code
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
28 * @short_description: Base class and element that can contain other elements
30 * #GstBin is an element that can contain other #GstElement, allowing them to be
32 * Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
33 * This makes the bin look like any other elements and enables creation of
34 * higher-level abstraction elements.
36 * A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
37 * want to create a toplevel bin because a normal bin doesn't have a bus or
38 * handle clock distribution of its own.
40 * After the bin has been created you will typically add elements to it with
41 * gst_bin_add(). You can remove elements with gst_bin_remove().
43 * An element can be retrieved from a bin with gst_bin_get_by_name(), using the
44 * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
45 * purposes and will query the parent bins when the element is not found in the
48 * An iterator of elements in a bin can be retrieved with
49 * gst_bin_iterate_elements(). Various other iterators exist to retrieve the
52 * gst_object_unref() is used to drop your reference to the bin.
54 * The #GstBin::element-added signal is fired whenever a new element is added to
55 * the bin. Likewise the #GstBin::element-removed signal is fired whenever an
56 * element is removed from the bin.
58 * <refsect2><title>Notes</title>
60 * A #GstBin internally intercepts every #GstMessage posted by its children and
61 * implements the following default behaviour for each of them:
64 * <term>GST_MESSAGE_EOS</term>
65 * <listitem><para>This message is only posted by sinks in the PLAYING
66 * state. If all sinks posted the EOS message, this bin will post and EOS
67 * message upwards.</para></listitem>
70 * <term>GST_MESSAGE_SEGMENT_START</term>
71 * <listitem><para>just collected and never forwarded upwards.
72 * The messages are used to decide when all elements have completed playback
73 * of their segment.</para></listitem>
76 * <term>GST_MESSAGE_SEGMENT_DONE</term>
77 * <listitem><para> Is posted by #GstBin when all elements that posted
78 * a SEGMENT_START have posted a SEGMENT_DONE.</para></listitem>
81 * <term>GST_MESSAGE_DURATION</term>
82 * <listitem><para> Is posted by an element that detected a change
83 * in the stream duration. The default bin behaviour is to clear any
84 * cached duration values so that the next duration query will perform
85 * a full duration recalculation. The duration change is posted to the
86 * application so that it can refetch the new duration with a duration
87 * query. Note that these messages can be posted before the bin is
88 * prerolled, in which case the duration query might fail.
92 * <term>GST_MESSAGE_CLOCK_LOST</term>
93 * <listitem><para> This message is posted by an element when it
94 * can no longer provide a clock. The default bin behaviour is to
95 * check if the lost clock was the one provided by the bin. If so and
96 * the bin is currently in the PLAYING state, the message is forwarded to
98 * This message is also generated when a clock provider is removed from
99 * the bin. If this message is received by the application, it should
100 * PAUSE the pipeline and set it back to PLAYING to force a new clock
105 * <term>GST_MESSAGE_CLOCK_PROVIDE</term>
106 * <listitem><para> This message is generated when an element
107 * can provide a clock. This mostly happens when a new clock
108 * provider is added to the bin. The default behaviour of the bin is to
109 * mark the currently selected clock as dirty, which will perform a clock
110 * recalculation the next time the bin is asked to provide a clock.
111 * This message is never sent tot the application but is forwarded to
112 * the parent of the bin.
116 * <term>OTHERS</term>
117 * <listitem><para> posted upwards.</para></listitem>
122 * A #GstBin implements the following default behaviour for answering to a
126 * <term>GST_QUERY_DURATION</term>
127 * <listitem><para>If the query has been asked before with the same format
128 * and the bin is a toplevel bin (ie. has no parent),
129 * use the cached previous value. If no previous value was cached, the
130 * query is sent to all sink elements in the bin and the MAXIMUM of all
131 * values is returned. If the bin is a toplevel bin the value is cached.
132 * If no sinks are available in the bin, the query fails.
136 * <term>GST_QUERY_POSITION</term>
137 * <listitem><para>The query is sent to all sink elements in the bin and the
138 * MAXIMUM of all values is returned. If no sinks are available in the bin,
143 * <term>OTHERS</term>
144 * <listitem><para>the query is forwarded to all sink elements, the result
145 * of the first sink that answers the query successfully is returned. If no
146 * sink is in the bin, the query fails.</para></listitem>
150 * A #GstBin will by default forward any event sent to it to all sink elements.
151 * If all the sinks return TRUE, the bin will also return TRUE, else FALSE is
152 * returned. If no sinks are in the bin, the event handler will return TRUE.
157 * Last reviewed on 2006-04-28 (0.10.6)
160 #include "gst_private.h"
162 #include "gstevent.h"
164 #include "gstmarshal.h"
167 #include "gsterror.h"
169 #include "gstindex.h"
170 #include "gstindexfactory.h"
171 #include "gstutils.h"
172 #include "gstchildproxy.h"
174 #ifdef GST_DISABLE_DEPRECATED
175 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
177 #define GstXmlNodePtr xmlNodePtr
178 #include <libxml/parser.h>
179 GstXmlNodePtr gst_object_save_thyself (GstObject * object,
180 GstXmlNodePtr parent);
181 void gst_object_restore_thyself (GstObject * object, GstXmlNodePtr parent);
182 GstElement *gst_xml_make_element (xmlNodePtr cur, GstObject * parent);
186 /* enable for DURATION caching.
187 * FIXME currently too many elements don't update
188 * their duration when it changes so we return inaccurate values. */
189 #undef DURATION_CACHING
191 /* latency is by default enabled now.
192 * live-preroll and no-live-preroll in the environment var GST_COMPAT
193 * to enables or disable it respectively.
195 static gboolean enable_latency = TRUE;
197 GST_DEBUG_CATEGORY_STATIC (bin_debug);
198 #define GST_CAT_DEFAULT bin_debug
200 /* a bin is toplevel if it has no parent or when it is configured to behave like
202 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
204 #define GST_BIN_GET_PRIVATE(obj) \
205 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
207 struct _GstBinPrivate
209 gboolean asynchandling;
210 /* if we get an ASYNC_DONE message from ourselves, this means that the
211 * subclass will simulate ASYNC behaviour without having ASYNC children. When
212 * such an ASYNC_DONE message is posted while we are doing a state change, we
213 * have to process the message after finishing the state change even when no
214 * child returned GST_STATE_CHANGE_ASYNC. */
215 gboolean pending_async_done;
217 guint32 structure_cookie;
221 /* forward messages from our children */
222 gboolean message_forward;
234 static void gst_bin_dispose (GObject * object);
236 static void gst_bin_set_property (GObject * object, guint prop_id,
237 const GValue * value, GParamSpec * pspec);
238 static void gst_bin_get_property (GObject * object, guint prop_id,
239 GValue * value, GParamSpec * pspec);
241 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
242 GstStateChange transition);
243 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
244 GstState newstate, GstState pending);
245 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
246 GstState * state, GstState * pending, GstClockTime timeout);
247 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
248 gboolean flag_pending);
249 static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
250 static void bin_push_state_continue (BinContinueData * data);
251 static void bin_do_eos (GstBin * bin);
253 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
254 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
256 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
257 static GstIndex *gst_bin_get_index_func (GstElement * element);
259 static GstClock *gst_bin_provide_clock_func (GstElement * element);
260 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
262 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
263 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
264 static GstBusSyncReply bin_bus_handler (GstBus * bus,
265 GstMessage * message, GstBin * bin);
266 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
268 static gboolean gst_bin_do_latency_func (GstBin * bin);
270 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
271 static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
272 static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
275 static void bin_remove_messages (GstBin * bin, GstObject * src,
276 GstMessageType types);
277 static void gst_bin_continue_func (BinContinueData * data);
278 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
279 static gint bin_element_is_src (GstElement * child, GstBin * bin);
281 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
283 /* Bin signals and properties */
292 #define DEFAULT_ASYNC_HANDLING FALSE
293 #define DEFAULT_MESSAGE_FORWARD FALSE
299 PROP_MESSAGE_FORWARD,
303 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
305 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
307 #define _do_init(type) \
309 const gchar *compat; \
310 static const GInterfaceInfo iface_info = { \
311 gst_bin_child_proxy_init, \
315 g_type_add_interface_static (type, GST_TYPE_CHILD_PROXY, &iface_info); \
317 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
318 "debugging info for the 'bin' container element"); \
320 /* compatibility stuff */ \
321 compat = g_getenv ("GST_COMPAT"); \
322 if (compat != NULL) { \
323 if (strstr (compat, "no-live-preroll")) \
324 enable_latency = FALSE; \
325 else if (strstr (compat, "live-preroll")) \
326 enable_latency = TRUE; \
330 GST_BOILERPLATE_FULL (GstBin, gst_bin, GstElement, GST_TYPE_ELEMENT, _do_init);
333 gst_bin_base_init (gpointer g_class)
335 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
337 gst_element_class_set_details_simple (gstelement_class, "Generic bin",
339 "Simple container object",
340 "Erik Walthinsen <omega@cse.ogi.edu>,"
341 "Wim Taymans <wim.taymans@gmail.com>");
345 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
351 bin = GST_BIN_CAST (child_proxy);
353 GST_OBJECT_LOCK (bin);
354 if ((res = g_list_nth_data (bin->children, index)))
355 gst_object_ref (res);
356 GST_OBJECT_UNLOCK (bin);
362 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
367 bin = GST_BIN_CAST (child_proxy);
369 GST_OBJECT_LOCK (bin);
370 num = bin->numchildren;
371 GST_OBJECT_UNLOCK (bin);
377 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
379 GstChildProxyInterface *iface = g_iface;
381 iface->get_children_count = gst_bin_child_proxy_get_children_count;
382 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
386 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
387 GValue * return_accu, const GValue * handler_return, gpointer dummy)
391 myboolean = g_value_get_boolean (handler_return);
392 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
393 g_value_set_boolean (return_accu, myboolean);
395 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
402 gst_bin_class_init (GstBinClass * klass)
404 GObjectClass *gobject_class;
405 GstObjectClass *gstobject_class;
406 GstElementClass *gstelement_class;
409 gobject_class = (GObjectClass *) klass;
410 gstobject_class = (GstObjectClass *) klass;
411 gstelement_class = (GstElementClass *) klass;
413 g_type_class_add_private (klass, sizeof (GstBinPrivate));
415 gobject_class->set_property = gst_bin_set_property;
416 gobject_class->get_property = gst_bin_get_property;
419 * GstBin:async-handling
421 * If set to #TRUE, the bin will handle asynchronous state changes.
422 * This should be used only if the bin subclass is modifying the state
423 * of its children on its own.
427 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
428 g_param_spec_boolean ("async-handling", "Async Handling",
429 "The bin will handle Asynchronous state changes",
430 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
433 * GstBin::element-added:
435 * @element: the #GstElement that was added to the bin
437 * Will be emitted after the element was added to the bin.
439 gst_bin_signals[ELEMENT_ADDED] =
440 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
441 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
442 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
444 * GstBin::element-removed:
446 * @element: the #GstElement that was removed from the bin
448 * Will be emitted after the element was removed from the bin.
450 gst_bin_signals[ELEMENT_REMOVED] =
451 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
452 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
453 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
455 * GstBin::do-latency:
458 * Will be emitted when the bin needs to perform latency calculations. This
459 * signal is only emited for toplevel bins or when async-handling is
462 * Only one signal handler is invoked. If no signals are connected, the
463 * default handler is invoked, which will query and distribute the lowest
464 * possible latency to all sinks.
466 * Connect to this signal if the default latency calculations are not
467 * sufficient, like when you need different latencies for different sinks in
472 gst_bin_signals[DO_LATENCY] =
473 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
474 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
475 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
476 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
479 * GstBin:message-forward
481 * Forward all children messages, even those that would normally be filtered by
482 * the bin. This can be interesting when one wants to be notified of the EOS
483 * state of individual elements, for example.
485 * The messages are converted to an ELEMENT message with the bin as the
486 * source. The structure of the message is named 'GstBinForwarded' and contains
487 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
492 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
493 g_param_spec_boolean ("message-forward", "Message Forward",
494 "Forwards all children messages",
495 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
497 gobject_class->dispose = gst_bin_dispose;
499 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
500 gstobject_class->save_thyself =
501 ((gpointer (*)(GstObject * object,
502 gpointer self)) * GST_DEBUG_FUNCPTR (gst_bin_save_thyself));
503 gstobject_class->restore_thyself =
504 ((void (*)(GstObject * object,
505 gpointer self)) *GST_DEBUG_FUNCPTR (gst_bin_restore_thyself));
508 gstelement_class->change_state =
509 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
510 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
511 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
512 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
513 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
514 gstelement_class->provide_clock =
515 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
516 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
518 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
519 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
521 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
522 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
523 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
525 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
527 GST_DEBUG ("creating bin thread pool");
530 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
532 g_critical ("could alloc threadpool %s", err->message);
537 gst_bin_init (GstBin * bin, GstBinClass * klass)
541 bin->numchildren = 0;
542 bin->children = NULL;
543 bin->children_cookie = 0;
544 bin->messages = NULL;
545 bin->provided_clock = NULL;
546 bin->clock_dirty = FALSE;
548 /* Set up a bus for listening to child elements */
549 bus = gst_bus_new ();
550 bin->child_bus = bus;
551 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
553 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
555 bin->priv = GST_BIN_GET_PRIVATE (bin);
556 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
557 bin->priv->structure_cookie = 0;
558 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
562 gst_bin_dispose (GObject * object)
564 GstBin *bin = GST_BIN_CAST (object);
565 GstBus **child_bus_p = &bin->child_bus;
566 GstClock **provided_clock_p = &bin->provided_clock;
567 GstElement **clock_provider_p = &bin->clock_provider;
568 GstIndex **index_p = &bin->priv->index;
570 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
572 GST_OBJECT_LOCK (object);
573 gst_object_replace ((GstObject **) child_bus_p, NULL);
574 gst_object_replace ((GstObject **) provided_clock_p, NULL);
575 gst_object_replace ((GstObject **) clock_provider_p, NULL);
576 gst_object_replace ((GstObject **) index_p, NULL);
577 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
578 GST_OBJECT_UNLOCK (object);
580 while (bin->children) {
581 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
583 if (G_UNLIKELY (bin->children != NULL)) {
584 g_critical ("could not remove elements from bin '%s'",
585 GST_STR_NULL (GST_OBJECT_NAME (object)));
588 G_OBJECT_CLASS (parent_class)->dispose (object);
593 * @name: the name of the new bin
595 * Creates a new bin with the given name.
597 * Returns: (transfer full): a new #GstBin
600 gst_bin_new (const gchar * name)
602 return gst_element_factory_make ("bin", name);
606 gst_bin_set_property (GObject * object, guint prop_id,
607 const GValue * value, GParamSpec * pspec)
611 gstbin = GST_BIN_CAST (object);
614 case PROP_ASYNC_HANDLING:
615 GST_OBJECT_LOCK (gstbin);
616 gstbin->priv->asynchandling = g_value_get_boolean (value);
617 GST_OBJECT_UNLOCK (gstbin);
619 case PROP_MESSAGE_FORWARD:
620 GST_OBJECT_LOCK (gstbin);
621 gstbin->priv->message_forward = g_value_get_boolean (value);
622 GST_OBJECT_UNLOCK (gstbin);
625 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
631 gst_bin_get_property (GObject * object, guint prop_id,
632 GValue * value, GParamSpec * pspec)
636 gstbin = GST_BIN_CAST (object);
639 case PROP_ASYNC_HANDLING:
640 GST_OBJECT_LOCK (gstbin);
641 g_value_set_boolean (value, gstbin->priv->asynchandling);
642 GST_OBJECT_UNLOCK (gstbin);
644 case PROP_MESSAGE_FORWARD:
645 GST_OBJECT_LOCK (gstbin);
646 g_value_set_boolean (value, gstbin->priv->message_forward);
647 GST_OBJECT_UNLOCK (gstbin);
650 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
655 /* return the cached index */
657 gst_bin_get_index_func (GstElement * element)
662 bin = GST_BIN_CAST (element);
664 GST_OBJECT_LOCK (bin);
665 if ((result = bin->priv->index))
666 gst_object_ref (result);
667 GST_OBJECT_UNLOCK (bin);
672 /* set the index on all elements in this bin
677 gst_bin_set_index_func (GstElement * element, GstIndex * index)
684 bin = GST_BIN_CAST (element);
686 GST_OBJECT_LOCK (bin);
687 old = bin->priv->index;
688 if (G_UNLIKELY (old == index))
691 gst_object_ref (index);
692 bin->priv->index = index;
693 GST_OBJECT_UNLOCK (bin);
696 gst_object_unref (old);
698 it = gst_bin_iterate_elements (bin);
700 /* set the index on all elements in the bin */
705 switch (gst_iterator_next (it, &data)) {
706 case GST_ITERATOR_OK:
708 GstElement *child = GST_ELEMENT_CAST (data);
710 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
711 GST_ELEMENT_NAME (child));
712 gst_element_set_index (child, index);
714 gst_object_unref (child);
717 case GST_ITERATOR_RESYNC:
718 GST_DEBUG_OBJECT (bin, "iterator doing resync");
719 gst_iterator_resync (it);
722 case GST_ITERATOR_DONE:
723 GST_DEBUG_OBJECT (bin, "iterator done");
728 gst_iterator_free (it);
733 GST_DEBUG_OBJECT (bin, "index was already set");
734 GST_OBJECT_UNLOCK (bin);
739 /* set the clock on all elements in this bin
744 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
751 bin = GST_BIN_CAST (element);
753 it = gst_bin_iterate_elements (bin);
759 switch (gst_iterator_next (it, &data)) {
760 case GST_ITERATOR_OK:
762 GstElement *child = GST_ELEMENT_CAST (data);
764 res &= gst_element_set_clock (child, clock);
766 gst_object_unref (child);
769 case GST_ITERATOR_RESYNC:
770 GST_DEBUG_OBJECT (bin, "iterator doing resync");
771 gst_iterator_resync (it);
775 case GST_ITERATOR_DONE:
776 GST_DEBUG_OBJECT (bin, "iterator done");
781 gst_iterator_free (it);
786 /* get the clock for this bin by asking all of the children in this bin
788 * The ref of the returned clock in increased so unref after usage.
790 * We loop the elements in state order and pick the last clock we can
791 * get. This makes sure we get a clock from the source.
796 gst_bin_provide_clock_func (GstElement * element)
798 GstClock *result = NULL;
799 GstElement *provider = NULL;
803 GstClock **provided_clock_p;
804 GstElement **clock_provider_p;
806 bin = GST_BIN_CAST (element);
808 GST_OBJECT_LOCK (bin);
809 if (!bin->clock_dirty)
812 GST_DEBUG_OBJECT (bin, "finding new clock");
814 it = gst_bin_sort_iterator_new (bin);
816 while (it->next (it, &val) == GST_ITERATOR_OK) {
817 GstElement *child = GST_ELEMENT_CAST (val);
820 clock = gst_element_provide_clock (child);
822 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
823 clock, GST_ELEMENT_NAME (child));
825 gst_object_unref (result);
826 gst_object_unref (provider);
831 gst_object_unref (child);
835 provided_clock_p = &bin->provided_clock;
836 clock_provider_p = &bin->clock_provider;
837 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
838 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
839 bin->clock_dirty = FALSE;
840 GST_DEBUG_OBJECT (bin,
841 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
843 /* Provider is not being returned to caller, just the result */
845 gst_object_unref (provider);
846 GST_OBJECT_UNLOCK (bin);
848 gst_iterator_free (it);
854 if ((result = bin->provided_clock))
855 gst_object_ref (result);
856 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
857 GST_OBJECT_UNLOCK (bin);
864 * functions for manipulating cached messages
869 GstMessageType types;
872 /* check if a message is of given src and type */
874 message_check (GstMessage * message, MessageFind * target)
879 eq &= GST_MESSAGE_SRC (message) == target->src;
881 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
882 GST_LOG ("looking at message %p: %d", message, eq);
888 find_message (GstBin * bin, GstObject * src, GstMessageType types)
896 result = g_list_find_custom (bin->messages, &find,
897 (GCompareFunc) message_check);
900 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
901 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
904 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
905 #ifndef GST_DISABLE_GST_DEBUG
909 for (i = 0; i < 32; i++)
910 if (types & (1 << i))
911 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
919 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
922 * A message that is cached and has the same SRC and type is replaced
923 * by the given message.
926 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
932 if ((src = GST_MESSAGE_SRC (message))) {
933 /* first find the previous message posted by this element */
934 if ((previous = find_message (bin, src, types))) {
935 GstMessage *previous_msg;
937 /* if we found a previous message, replace it */
938 previous_msg = previous->data;
939 previous->data = message;
941 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
942 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
943 GST_MESSAGE_TYPE_NAME (message));
945 gst_message_unref (previous_msg);
947 /* keep new message */
948 bin->messages = g_list_prepend (bin->messages, message);
950 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
951 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
954 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
955 GST_MESSAGE_TYPE_NAME (message));
957 gst_message_unref (message);
962 /* with LOCK. Remove all messages of given types */
964 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
972 for (walk = bin->messages; walk; walk = next) {
973 GstMessage *message = (GstMessage *) walk->data;
975 next = g_list_next (walk);
977 if (message_check (message, &find) == 0) {
978 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
979 "deleting message %p of types 0x%08x", message, types);
980 bin->messages = g_list_delete_link (bin->messages, walk);
981 gst_message_unref (message);
983 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
984 "not deleting message %p of type 0x%08x", message,
985 GST_MESSAGE_TYPE (message));
991 /* Check if the bin is EOS. We do this by scanning all sinks and
992 * checking if they posted an EOS message.
994 * call with bin LOCK */
996 is_eos (GstBin * bin, guint32 * seqnum)
1003 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1004 GstElement *element;
1006 element = GST_ELEMENT_CAST (walk->data);
1007 if (bin_element_is_sink (element, bin) == 0) {
1008 /* check if element posted EOS */
1010 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
1011 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1012 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1015 GST_DEBUG ("sink '%s' did not post EOS yet",
1016 GST_ELEMENT_NAME (element));
1022 /* FIXME: Some tests (e.g. elements/capsfilter) use
1023 * pipelines with a dangling sinkpad but no sink element.
1024 * These tests assume that no EOS message is ever
1025 * posted on the bus so let's keep that behaviour.
1026 * In valid pipelines this doesn't make a difference.
1028 return result && n_eos > 0;
1032 unlink_pads (GstPad * pad)
1036 if ((peer = gst_pad_get_peer (pad))) {
1037 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1038 gst_pad_unlink (pad, peer);
1040 gst_pad_unlink (peer, pad);
1041 gst_object_unref (peer);
1043 gst_object_unref (pad);
1046 /* vmethod that adds an element to a bin
1051 gst_bin_add_func (GstBin * bin, GstElement * element)
1055 gboolean is_sink, is_source;
1056 GstMessage *clock_message = NULL, *async_message = NULL;
1057 GstStateChangeReturn ret;
1059 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1061 /* we obviously can't add ourself to ourself */
1062 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1065 /* get the element name to make sure it is unique in this bin. */
1066 GST_OBJECT_LOCK (element);
1067 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1068 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1069 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1070 GST_OBJECT_UNLOCK (element);
1072 GST_OBJECT_LOCK (bin);
1074 /* then check to see if the element's name is already taken in the bin,
1075 * we can safely take the lock here. This check is probably bogus because
1076 * you can safely change the element name after this check and before setting
1077 * the object parent. The window is very small though... */
1078 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1079 goto duplicate_name;
1081 /* set the element's parent and add the element to the bin's list of children */
1082 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1083 GST_OBJECT_CAST (bin))))
1086 /* if we add a sink we become a sink */
1088 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1090 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1093 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1095 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1097 if (gst_element_provides_clock (element)) {
1098 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1100 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1103 bin->children = g_list_prepend (bin->children, element);
1105 bin->children_cookie++;
1106 bin->priv->structure_cookie++;
1108 /* distribute the bus */
1109 gst_element_set_bus (element, bin->child_bus);
1111 /* propagate the current base_time, start_time and clock */
1112 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1113 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1114 /* it's possible that the element did not accept the clock but
1115 * that is not important right now. When the pipeline goes to PLAYING,
1116 * a new clock will be selected */
1117 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1118 /* set the cached index on the children */
1119 if (bin->priv->index)
1120 gst_element_set_index (element, bin->priv->index);
1122 ret = GST_STATE_RETURN (bin);
1123 /* no need to update the state if we are in error */
1124 if (ret == GST_STATE_CHANGE_FAILURE)
1125 goto no_state_recalc;
1127 /* update the bin state, the new element could have been an ASYNC or
1128 * NO_PREROLL element */
1129 ret = GST_STATE_RETURN (element);
1130 GST_DEBUG_OBJECT (bin, "added %s element",
1131 gst_element_state_change_return_get_name (ret));
1134 case GST_STATE_CHANGE_ASYNC:
1136 /* create message to track this aync element when it posts an async-done
1139 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1142 case GST_STATE_CHANGE_NO_PREROLL:
1143 /* ignore all async elements we might have and commit our state */
1144 bin_handle_async_done (bin, ret, FALSE);
1146 case GST_STATE_CHANGE_FAILURE:
1153 GST_OBJECT_UNLOCK (bin);
1155 /* post the messages on the bus of the element so that the bin can handle
1158 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1161 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1163 /* unlink all linked pads */
1164 it = gst_element_iterate_pads (element);
1165 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1166 gst_iterator_free (it);
1168 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1172 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1173 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1177 /* ERROR handling here */
1180 GST_OBJECT_LOCK (bin);
1181 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1182 GST_OBJECT_UNLOCK (bin);
1187 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1188 elem_name, GST_ELEMENT_NAME (bin));
1189 GST_OBJECT_UNLOCK (bin);
1195 g_warning ("Element '%s' already has parent", elem_name);
1196 GST_OBJECT_UNLOCK (bin);
1205 * @element: (transfer full): the #GstElement to add
1207 * Adds the given element to the bin. Sets the element's parent, and thus
1208 * takes ownership of the element. An element can only be added to one bin.
1210 * If the element's pads are linked to other pads, the pads will be unlinked
1211 * before the element is added to the bin.
1214 * When you add an element to an already-running pipeline, you will have to
1215 * take care to set the state of the newly-added element to the desired
1216 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1217 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1218 * The bin or pipeline will not take care of this for you.
1223 * Returns: TRUE if the element could be added, FALSE if
1224 * the bin does not want to accept the element.
1227 gst_bin_add (GstBin * bin, GstElement * element)
1229 GstBinClass *bclass;
1232 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1233 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1235 bclass = GST_BIN_GET_CLASS (bin);
1237 if (G_UNLIKELY (bclass->add_element == NULL))
1240 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1241 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1242 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1244 result = bclass->add_element (bin, element);
1248 /* ERROR handling */
1251 g_warning ("adding elements to bin '%s' is not supported",
1252 GST_ELEMENT_NAME (bin));
1257 /* remove an element from the bin
1262 gst_bin_remove_func (GstBin * bin, GstElement * element)
1266 gboolean is_sink, is_source, othersink, othersource, found;
1267 GstMessage *clock_message = NULL;
1268 GstClock **provided_clock_p;
1269 GstElement **clock_provider_p;
1271 gboolean other_async, this_async, have_no_preroll;
1272 GstStateChangeReturn ret;
1274 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1276 GST_OBJECT_LOCK (element);
1277 /* Check if the element is already being removed and immediately
1279 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1280 goto already_removing;
1282 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1283 /* grab element name so we can print it */
1284 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1285 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1286 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1287 GST_OBJECT_UNLOCK (element);
1289 /* unlink all linked pads */
1290 it = gst_element_iterate_pads (element);
1291 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1292 gst_iterator_free (it);
1294 GST_OBJECT_LOCK (bin);
1297 othersource = FALSE;
1298 have_no_preroll = FALSE;
1299 /* iterate the elements, we collect which ones are async and no_preroll. We
1300 * also remove the element when we find it. */
1301 for (walk = bin->children; walk; walk = next) {
1302 GstElement *child = GST_ELEMENT_CAST (walk->data);
1304 next = g_list_next (walk);
1306 if (child == element) {
1308 /* remove the element */
1309 bin->children = g_list_delete_link (bin->children, walk);
1311 gboolean child_sink, child_source;
1313 GST_OBJECT_LOCK (child);
1314 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1315 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1316 /* when we remove a sink, check if there are other sinks. */
1317 if (is_sink && !othersink && child_sink)
1319 if (is_source && !othersource && child_source)
1321 /* check if we have NO_PREROLL children */
1322 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1323 have_no_preroll = TRUE;
1324 GST_OBJECT_UNLOCK (child);
1328 /* the element must have been in the bin's list of children */
1329 if (G_UNLIKELY (!found))
1332 /* we now removed the element from the list of elements, increment the cookie
1333 * so that others can detect a change in the children list. */
1335 bin->children_cookie++;
1336 bin->priv->structure_cookie++;
1338 if (is_sink && !othersink) {
1339 /* we're not a sink anymore */
1340 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1341 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1343 if (is_source && !othersource) {
1344 /* we're not a source anymore */
1345 GST_DEBUG_OBJECT (bin, "we removed the last source");
1346 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1350 /* if the clock provider for this element is removed, we lost
1351 * the clock as well, we need to inform the parent of this
1352 * so that it can select a new clock */
1353 if (bin->clock_provider == element) {
1354 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1355 bin->clock_dirty = TRUE;
1357 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1358 provided_clock_p = &bin->provided_clock;
1359 clock_provider_p = &bin->clock_provider;
1360 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1361 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1364 /* remove messages for the element, if there was a pending ASYNC_START
1365 * message we must see if removing the element caused the bin to lose its
1368 other_async = FALSE;
1369 for (walk = bin->messages; walk; walk = next) {
1370 GstMessage *message = (GstMessage *) walk->data;
1371 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1374 next = g_list_next (walk);
1377 switch (GST_MESSAGE_TYPE (message)) {
1378 case GST_MESSAGE_ASYNC_START:
1384 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1386 case GST_MESSAGE_STRUCTURE_CHANGE:
1390 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1392 /* it's unlikely that this message is still in the list of messages
1393 * because this would mean that a link/unlink is busy in another thread
1394 * while we remove the element. We still have to remove the message
1395 * because we might not receive the done message anymore when the element
1396 * is removed from the bin. */
1397 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1398 if (owner == element)
1409 /* delete all message types */
1410 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1411 message, elem_name);
1412 bin->messages = g_list_delete_link (bin->messages, walk);
1413 gst_message_unref (message);
1417 /* get last return */
1418 ret = GST_STATE_RETURN (bin);
1420 /* no need to update the state if we are in error */
1421 if (ret == GST_STATE_CHANGE_FAILURE)
1422 goto no_state_recalc;
1424 if (!other_async && this_async) {
1425 /* all other elements were not async and we removed the async one,
1426 * handle the async-done case because we are not async anymore now. */
1427 GST_DEBUG_OBJECT (bin,
1428 "we removed the last async element, have no_preroll %d",
1431 /* the current state return of the bin depends on if there are no_preroll
1432 * elements in the pipeline or not */
1433 if (have_no_preroll)
1434 ret = GST_STATE_CHANGE_NO_PREROLL;
1436 ret = GST_STATE_CHANGE_SUCCESS;
1438 bin_handle_async_done (bin, ret, FALSE);
1440 GST_DEBUG_OBJECT (bin,
1441 "recalc state preroll: %d, other async: %d, this async %d",
1442 have_no_preroll, other_async, this_async);
1444 if (have_no_preroll) {
1445 ret = GST_STATE_CHANGE_NO_PREROLL;
1446 } else if (other_async) {
1447 /* there are other async elements and we were not doing an async state
1448 * change, change our pending state and go async */
1449 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1450 GST_STATE_NEXT (bin) = GST_STATE (bin);
1451 GST_STATE_PENDING (bin) = GST_STATE (bin);
1453 ret = GST_STATE_CHANGE_ASYNC;
1455 GST_STATE_RETURN (bin) = ret;
1458 GST_OBJECT_UNLOCK (bin);
1461 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1463 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1467 gst_element_set_bus (element, NULL);
1469 /* Clear the clock we provided to the element */
1470 gst_element_set_clock (element, NULL);
1472 /* we ref here because after the _unparent() the element can be disposed
1473 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1474 gst_object_ref (element);
1475 gst_object_unparent (GST_OBJECT_CAST (element));
1477 GST_OBJECT_LOCK (element);
1478 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1479 GST_OBJECT_UNLOCK (element);
1481 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1482 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1484 /* element is really out of our control now */
1485 gst_object_unref (element);
1489 /* ERROR handling */
1492 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1493 GST_ELEMENT_NAME (bin));
1494 GST_OBJECT_UNLOCK (bin);
1500 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1501 GST_OBJECT_UNLOCK (element);
1509 * @element: (transfer none): the #GstElement to remove
1511 * Removes the element from the bin, unparenting it as well.
1512 * Unparenting the element means that the element will be dereferenced,
1513 * so if the bin holds the only reference to the element, the element
1514 * will be freed in the process of removing it from the bin. If you
1515 * want the element to still exist after removing, you need to call
1516 * gst_object_ref() before removing it from the bin.
1518 * If the element's pads are linked to other pads, the pads will be unlinked
1519 * before the element is removed from the bin.
1523 * Returns: TRUE if the element could be removed, FALSE if
1524 * the bin does not want to remove the element.
1527 gst_bin_remove (GstBin * bin, GstElement * element)
1529 GstBinClass *bclass;
1532 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1533 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1535 bclass = GST_BIN_GET_CLASS (bin);
1537 if (G_UNLIKELY (bclass->remove_element == NULL))
1540 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1541 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1543 result = bclass->remove_element (bin, element);
1547 /* ERROR handling */
1550 g_warning ("removing elements from bin '%s' is not supported",
1551 GST_ELEMENT_NAME (bin));
1556 static GstIteratorItem
1557 iterate_child (GstIterator * it, GstElement * child)
1559 gst_object_ref (child);
1560 return GST_ITERATOR_ITEM_PASS;
1564 * gst_bin_iterate_elements:
1567 * Gets an iterator for the elements in this bin.
1569 * Each element yielded by the iterator will have its refcount increased, so
1572 * MT safe. Caller owns returned value.
1574 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1577 gst_bin_iterate_elements (GstBin * bin)
1579 GstIterator *result;
1581 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1583 GST_OBJECT_LOCK (bin);
1584 /* add ref because the iterator refs the bin. When the iterator
1585 * is freed it will unref the bin again using the provided dispose
1587 gst_object_ref (bin);
1588 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1589 GST_OBJECT_GET_LOCK (bin),
1590 &bin->children_cookie,
1593 (GstIteratorItemFunction) iterate_child,
1594 (GstIteratorDisposeFunction) gst_object_unref);
1595 GST_OBJECT_UNLOCK (bin);
1600 static GstIteratorItem
1601 iterate_child_recurse (GstIterator * it, GstElement * child)
1603 gst_object_ref (child);
1604 if (GST_IS_BIN (child)) {
1605 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1607 gst_iterator_push (it, other);
1609 return GST_ITERATOR_ITEM_PASS;
1613 * gst_bin_iterate_recurse:
1616 * Gets an iterator for the elements in this bin.
1617 * This iterator recurses into GstBin children.
1619 * Each element yielded by the iterator will have its refcount increased, so
1622 * MT safe. Caller owns returned value.
1624 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1627 gst_bin_iterate_recurse (GstBin * bin)
1629 GstIterator *result;
1631 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1633 GST_OBJECT_LOCK (bin);
1634 /* add ref because the iterator refs the bin. When the iterator
1635 * is freed it will unref the bin again using the provided dispose
1637 gst_object_ref (bin);
1638 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1639 GST_OBJECT_GET_LOCK (bin),
1640 &bin->children_cookie,
1643 (GstIteratorItemFunction) iterate_child_recurse,
1644 (GstIteratorDisposeFunction) gst_object_unref);
1645 GST_OBJECT_UNLOCK (bin);
1650 /* returns 0 when TRUE because this is a GCompareFunc */
1653 bin_element_is_sink (GstElement * child, GstBin * bin)
1657 /* we lock the child here for the remainder of the function to
1658 * get its name and flag safely. */
1659 GST_OBJECT_LOCK (child);
1660 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1662 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1663 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1665 GST_OBJECT_UNLOCK (child);
1666 return is_sink ? 0 : 1;
1670 sink_iterator_filter (GstElement * child, GstBin * bin)
1672 if (bin_element_is_sink (child, bin) == 0) {
1673 /* returns 0 because this is a GCompareFunc */
1676 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1678 gst_object_unref (child);
1684 * gst_bin_iterate_sinks:
1687 * Gets an iterator for all elements in the bin that have the
1688 * #GST_ELEMENT_IS_SINK flag set.
1690 * Each element yielded by the iterator will have its refcount increased, so
1693 * MT safe. Caller owns returned value.
1695 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1698 gst_bin_iterate_sinks (GstBin * bin)
1700 GstIterator *children;
1701 GstIterator *result;
1703 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1705 children = gst_bin_iterate_elements (bin);
1706 result = gst_iterator_filter (children,
1707 (GCompareFunc) sink_iterator_filter, bin);
1712 /* returns 0 when TRUE because this is a GCompareFunc */
1715 bin_element_is_src (GstElement * child, GstBin * bin)
1719 /* we lock the child here for the remainder of the function to
1720 * get its name and other info safely. */
1721 GST_OBJECT_LOCK (child);
1722 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1724 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1725 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1727 GST_OBJECT_UNLOCK (child);
1728 return is_src ? 0 : 1;
1732 src_iterator_filter (GstElement * child, GstBin * bin)
1734 if (bin_element_is_src (child, bin) == 0) {
1735 /* returns 0 because this is a GCompareFunc */
1738 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1740 gst_object_unref (child);
1746 * gst_bin_iterate_sources:
1749 * Gets an iterator for all elements in the bin that have the
1750 * #GST_ELEMENT_IS_SOURCE flag set.
1752 * Each element yielded by the iterator will have its refcount increased, so
1755 * MT safe. Caller owns returned value.
1757 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1760 gst_bin_iterate_sources (GstBin * bin)
1762 GstIterator *children;
1763 GstIterator *result;
1765 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1767 children = gst_bin_iterate_elements (bin);
1768 result = gst_iterator_filter (children,
1769 (GCompareFunc) src_iterator_filter, bin);
1777 static GstStateChangeReturn
1778 gst_bin_get_state_func (GstElement * element, GstState * state,
1779 GstState * pending, GstClockTime timeout)
1781 GstStateChangeReturn ret;
1783 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1785 ret = parent_class->get_state (element, state, pending, timeout);
1790 /***********************************************
1791 * Topologically sorted iterator
1792 * see http://en.wikipedia.org/wiki/Topological_sorting
1794 * For each element in the graph, an entry is kept in a HashTable
1795 * with its number of srcpad connections (degree).
1796 * We then change state of all elements without dependencies
1797 * (degree 0) and decrement the degree of all elements connected
1798 * on the sinkpads. When an element reaches degree 0, its state is
1800 * When all elements are handled the algorithm stops.
1802 typedef struct _GstBinSortIterator
1805 GQueue queue; /* elements queued for state change */
1806 GstBin *bin; /* bin we iterate */
1807 gint mode; /* adding or removing dependency */
1808 GstElement *best; /* next element with least dependencies */
1809 gint best_deg; /* best degree */
1810 GHashTable *hash; /* hashtable with element dependencies */
1811 gboolean dirty; /* we detected structure change */
1812 } GstBinSortIterator;
1814 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1815 #define HASH_SET_DEGREE(bit, elem, deg) \
1816 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1817 #define HASH_GET_DEGREE(bit, elem) \
1818 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1820 /* add element to queue of next elements in the iterator.
1821 * We push at the tail to give higher priority elements a
1824 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1826 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1827 GST_ELEMENT_NAME (element));
1828 gst_object_ref (element);
1829 g_queue_push_tail (&bit->queue, element);
1830 HASH_SET_DEGREE (bit, element, -1);
1834 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1838 if ((find = g_queue_find (&bit->queue, element))) {
1839 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1840 GST_ELEMENT_NAME (element));
1842 g_queue_delete_link (&bit->queue, find);
1843 gst_object_unref (element);
1845 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1846 GST_ELEMENT_NAME (element));
1850 /* clear the queue, unref all objects as we took a ref when
1851 * we added them to the queue */
1853 clear_queue (GQueue * queue)
1857 while ((p = g_queue_pop_head (queue)))
1858 gst_object_unref (p);
1861 /* set all degrees to 0. Elements marked as a sink are
1862 * added to the queue immediately. Since we only look at the SINK flag of the
1863 * element, it is possible that we add non-sinks to the queue. These will be
1864 * removed from the queue again when we can prove that it provides data for some
1867 reset_degree (GstElement * element, GstBinSortIterator * bit)
1871 /* sinks are added right away */
1872 GST_OBJECT_LOCK (element);
1873 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1874 GST_OBJECT_UNLOCK (element);
1877 add_to_queue (bit, element);
1879 /* others are marked with 0 and handled when sinks are done */
1880 HASH_SET_DEGREE (bit, element, 0);
1884 /* adjust the degree of all elements connected to the given
1885 * element. If a degree of an element drops to 0, it is
1886 * added to the queue of elements to schedule next.
1888 * We have to make sure not to cross the bin boundary this element
1892 update_degree (GstElement * element, GstBinSortIterator * bit)
1894 gboolean linked = FALSE;
1896 GST_OBJECT_LOCK (element);
1897 /* don't touch degree if element has no sinkpads */
1898 if (element->numsinkpads != 0) {
1899 /* loop over all sinkpads, decrement degree for all connected
1900 * elements in this bin */
1903 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1906 pad = GST_PAD_CAST (pads->data);
1908 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1909 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1910 GST_MESSAGE_STRUCTURE_CHANGE))) {
1911 /* mark the iterator as dirty because we won't be updating the degree
1912 * of the peer parent now. This would result in the 'loop detected'
1913 * later on because the peer parent element could become the best next
1914 * element with a degree > 0. We will simply continue our state
1915 * changes and we'll eventually resync when the unlink completed and
1916 * the iterator cookie is updated. */
1921 if ((peer = gst_pad_get_peer (pad))) {
1922 GstElement *peer_element;
1924 if ((peer_element = gst_pad_get_parent_element (peer))) {
1925 GST_OBJECT_LOCK (peer_element);
1926 /* check that we don't go outside of this bin */
1927 if (GST_OBJECT_CAST (peer_element)->parent ==
1928 GST_OBJECT_CAST (bit->bin)) {
1929 gint old_deg, new_deg;
1931 old_deg = HASH_GET_DEGREE (bit, peer_element);
1933 /* check to see if we added an element as sink that was not really a
1934 * sink because it was connected to some other element. */
1935 if (old_deg == -1) {
1936 remove_from_queue (bit, peer_element);
1939 new_deg = old_deg + bit->mode;
1941 GST_DEBUG_OBJECT (bit->bin,
1942 "change element %s, degree %d->%d, linked to %s",
1943 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1944 GST_ELEMENT_NAME (element));
1946 /* update degree, it is possible that an element was in 0 and
1947 * reaches -1 here. This would mean that the element had no sinkpads
1948 * but became linked while the state change was happening. We will
1949 * resync on this with the structure change message. */
1951 /* degree hit 0, add to queue */
1952 add_to_queue (bit, peer_element);
1954 HASH_SET_DEGREE (bit, peer_element, new_deg);
1958 GST_OBJECT_UNLOCK (peer_element);
1959 gst_object_unref (peer_element);
1961 gst_object_unref (peer);
1966 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1967 GST_ELEMENT_NAME (element));
1969 GST_OBJECT_UNLOCK (element);
1972 /* find the next best element not handled yet. This is the one
1973 * with the lowest non-negative degree */
1975 find_element (GstElement * element, GstBinSortIterator * bit)
1979 /* element is already handled */
1980 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1983 /* first element or element with smaller degree */
1984 if (bit->best == NULL || bit->best_deg > degree) {
1985 bit->best = element;
1986 bit->best_deg = degree;
1990 /* get next element in iterator. the returned element has the
1991 * refcount increased */
1992 static GstIteratorResult
1993 gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
1995 GstBin *bin = bit->bin;
1997 /* empty queue, we have to find a next best element */
1998 if (g_queue_is_empty (&bit->queue)) {
2002 bit->best_deg = G_MAXINT;
2003 g_list_foreach (bin->children, (GFunc) find_element, bit);
2004 if ((best = bit->best)) {
2005 /* when we detected an unlink, don't warn because our degrees might be
2006 * screwed up. We will resync later */
2007 if (bit->best_deg != 0 && !bit->dirty) {
2008 /* we don't fail on this one yet */
2009 GST_WARNING_OBJECT (bin, "loop dected in graph");
2010 g_warning ("loop detected in the graph of bin '%s'!!",
2011 GST_ELEMENT_NAME (bin));
2013 /* best unhandled element, schedule as next element */
2014 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2015 GST_ELEMENT_NAME (best));
2016 gst_object_ref (best);
2017 HASH_SET_DEGREE (bit, best, -1);
2020 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2021 /* no more unhandled elements, we are done */
2022 return GST_ITERATOR_DONE;
2025 /* everything added to the queue got reffed */
2026 *result = g_queue_pop_head (&bit->queue);
2029 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
2030 /* update degrees of linked elements */
2031 update_degree (GST_ELEMENT_CAST (*result), bit);
2033 return GST_ITERATOR_OK;
2036 /* clear queues, recalculate the degrees and restart. */
2038 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2040 GstBin *bin = bit->bin;
2042 GST_DEBUG_OBJECT (bin, "resync");
2044 clear_queue (&bit->queue);
2046 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2047 /* calc degrees, incrementing */
2049 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2050 /* for the rest of the function we decrement the degrees */
2054 /* clear queues, unref bin and free iterator. */
2056 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2058 GstBin *bin = bit->bin;
2060 GST_DEBUG_OBJECT (bin, "free");
2061 clear_queue (&bit->queue);
2062 g_hash_table_destroy (bit->hash);
2063 gst_object_unref (bin);
2067 /* should be called with the bin LOCK held */
2068 static GstIterator *
2069 gst_bin_sort_iterator_new (GstBin * bin)
2071 GstBinSortIterator *result;
2073 /* we don't need an ItemFunction because we ref the items in the _next
2075 result = (GstBinSortIterator *)
2076 gst_iterator_new (sizeof (GstBinSortIterator),
2078 GST_OBJECT_GET_LOCK (bin),
2079 &bin->priv->structure_cookie,
2080 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2081 (GstIteratorItemFunction) NULL,
2082 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2083 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2084 g_queue_init (&result->queue);
2085 result->hash = g_hash_table_new (NULL, NULL);
2086 gst_object_ref (bin);
2088 gst_bin_sort_iterator_resync (result);
2090 return (GstIterator *) result;
2094 * gst_bin_iterate_sorted:
2097 * Gets an iterator for the elements in this bin in topologically
2098 * sorted order. This means that the elements are returned from
2099 * the most downstream elements (sinks) to the sources.
2101 * This function is used internally to perform the state changes
2102 * of the bin elements and for clock selection.
2104 * Each element yielded by the iterator will have its refcount increased, so
2107 * MT safe. Caller owns returned value.
2109 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2112 gst_bin_iterate_sorted (GstBin * bin)
2114 GstIterator *result;
2116 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2118 GST_OBJECT_LOCK (bin);
2119 result = gst_bin_sort_iterator_new (bin);
2120 GST_OBJECT_UNLOCK (bin);
2125 static GstStateChangeReturn
2126 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2127 GstClockTime base_time, GstClockTime start_time, GstState current,
2130 GstStateChangeReturn ret;
2131 GstState pending, child_current, child_pending;
2135 GST_STATE_LOCK (element);
2137 GST_OBJECT_LOCK (element);
2138 /* set base_time and start time on child */
2139 GST_ELEMENT_START_TIME (element) = start_time;
2140 element->base_time = base_time;
2141 /* peel off the locked flag */
2142 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2143 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2144 ret = GST_STATE_RETURN (element);
2145 child_current = GST_STATE (element);
2146 child_pending = GST_STATE_PENDING (element);
2147 GST_OBJECT_UNLOCK (element);
2149 /* skip locked elements */
2150 if (G_UNLIKELY (locked))
2153 /* if the element was no preroll, just start changing the state regardless
2154 * if it had async elements (in the case of a bin) because they won't preroll
2156 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2157 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2161 GST_OBJECT_LOCK (bin);
2162 pending = GST_STATE_PENDING (bin);
2164 /* Try not to change the state of elements that are already in the state we're
2166 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2167 (child_pending == GST_STATE_VOID_PENDING &&
2168 ((pending > child_current && next > child_current) ||
2169 (pending < child_current && next < child_current)))))
2172 /* the element was busy with an upwards async state change, we must wait for
2173 * an ASYNC_DONE message before we attemp to change the state. */
2175 find_message (bin, GST_OBJECT_CAST (element),
2176 GST_MESSAGE_ASYNC_START))) {
2177 #ifndef GST_DISABLE_GST_DEBUG
2178 GstMessage *message = GST_MESSAGE_CAST (found->data);
2180 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2181 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2183 /* only wait for upward state changes */
2184 if (next > current) {
2185 /* We found an async element check if we can force its state to change or
2186 * if we have to wait for it to preroll. */
2187 if (G_UNLIKELY (!enable_latency)) {
2188 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2189 "\tto preroll in order to perform correct latency calculations.\n"
2190 "\tPlease verify that the application continues to work correctly by\n"
2191 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2192 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2199 GST_OBJECT_UNLOCK (bin);
2202 GST_DEBUG_OBJECT (bin,
2203 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2204 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2205 GST_TIME_ARGS (base_time));
2208 ret = gst_element_set_state (element, next);
2210 GST_STATE_UNLOCK (element);
2216 GST_DEBUG_OBJECT (element,
2217 "element is locked, return previous return %s",
2218 gst_element_state_change_return_get_name (ret));
2219 GST_STATE_UNLOCK (element);
2224 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2225 GST_OBJECT_UNLOCK (bin);
2226 GST_STATE_UNLOCK (element);
2227 return GST_STATE_CHANGE_ASYNC;
2231 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2232 "skipping transition from %s to %s, since bin pending"
2233 " is %s : last change state return follows",
2234 gst_element_state_get_name (child_current),
2235 gst_element_state_get_name (next),
2236 gst_element_state_get_name (pending));
2237 GST_OBJECT_UNLOCK (bin);
2238 GST_STATE_UNLOCK (element);
2243 /* gst_iterator_fold functions for pads_activate
2244 * Stop the iterator if activating one pad failed. */
2246 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2248 gboolean cont = TRUE;
2250 if (!(cont = gst_pad_set_active (pad, *active)))
2251 g_value_set_boolean (ret, FALSE);
2253 gst_pad_set_caps (pad, NULL);
2255 /* unref the object that was reffed for us by _fold */
2256 gst_object_unref (pad);
2260 /* returns false on error or early cutout of the fold, true if all
2261 * pads in @iter were (de)activated successfully. */
2263 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2265 GstIteratorResult ires;
2268 /* no need to unset this later, it's just a boolean */
2269 g_value_init (&ret, G_TYPE_BOOLEAN);
2270 g_value_set_boolean (&ret, TRUE);
2273 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2276 case GST_ITERATOR_RESYNC:
2277 /* need to reset the result again */
2278 g_value_set_boolean (&ret, TRUE);
2279 gst_iterator_resync (iter);
2281 case GST_ITERATOR_DONE:
2282 /* all pads iterated, return collected value */
2285 /* iterator returned _ERROR or premature end with _OK,
2286 * mark an error and exit */
2287 g_value_set_boolean (&ret, FALSE);
2292 /* return collected value */
2293 return g_value_get_boolean (&ret);
2296 /* is called with STATE_LOCK
2299 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2304 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2306 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2307 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2308 gst_iterator_free (iter);
2309 if (G_UNLIKELY (!fold_ok))
2312 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2319 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2325 * gst_bin_recalculate_latency:
2328 * Query @bin for the current latency using and reconfigures this latency to all the
2329 * elements with a LATENCY event.
2331 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2332 * is posted on the bus.
2334 * This function simply emits the 'do-latency' signal so any custom latency
2335 * calculations will be performed.
2337 * Returns: %TRUE if the latency could be queried and reconfigured.
2342 gst_bin_recalculate_latency (GstBin * bin)
2346 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2347 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2353 gst_bin_do_latency_func (GstBin * bin)
2356 GstElement *element;
2357 GstClockTime min_latency, max_latency;
2360 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2362 element = GST_ELEMENT_CAST (bin);
2364 GST_DEBUG_OBJECT (element, "querying latency");
2366 query = gst_query_new_latency ();
2367 if ((res = gst_element_query (element, query))) {
2370 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2372 GST_DEBUG_OBJECT (element,
2373 "got min latency %" GST_TIME_FORMAT ", max latency %"
2374 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2375 GST_TIME_ARGS (max_latency), live);
2377 if (max_latency < min_latency) {
2378 /* this is an impossible situation, some parts of the pipeline might not
2379 * work correctly. We post a warning for now. */
2380 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2381 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2382 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2383 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2386 /* configure latency on elements */
2387 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2389 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2390 GST_TIME_ARGS (min_latency));
2392 GST_WARNING_OBJECT (element,
2393 "did not really configure latency of %" GST_TIME_FORMAT,
2394 GST_TIME_ARGS (min_latency));
2397 /* this is not a real problem, we just don't configure any latency. */
2398 GST_WARNING_OBJECT (element, "failed to query latency");
2400 gst_query_unref (query);
2406 gst_bin_state_changed (GstElement * element, GstState oldstate,
2407 GstState newstate, GstState pending)
2409 GstElementClass *pklass = (GstElementClass *) parent_class;
2411 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2412 bin_do_eos (GST_BIN_CAST (element));
2414 if (pklass->state_changed)
2415 pklass->state_changed (element, oldstate, newstate, pending);
2418 static GstStateChangeReturn
2419 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2422 GstStateChangeReturn ret;
2423 GstState current, next;
2424 gboolean have_async;
2425 gboolean have_no_preroll;
2426 GstClockTime base_time, start_time;
2430 /* we don't need to take the STATE_LOCK, it is already taken */
2431 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2432 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2434 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2435 "changing state of children from %s to %s",
2436 gst_element_state_get_name (current), gst_element_state_get_name (next));
2438 bin = GST_BIN_CAST (element);
2441 case GST_STATE_PLAYING:
2445 GST_OBJECT_LOCK (bin);
2446 toplevel = BIN_IS_TOPLEVEL (bin);
2447 GST_OBJECT_UNLOCK (bin);
2450 gst_bin_recalculate_latency (bin);
2453 case GST_STATE_PAUSED:
2454 /* Clear EOS list on next PAUSED */
2455 GST_OBJECT_LOCK (bin);
2456 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2457 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2458 bin->priv->posted_eos = FALSE;
2459 GST_OBJECT_UNLOCK (bin);
2460 if (current == GST_STATE_READY)
2461 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2462 goto activate_failure;
2464 case GST_STATE_READY:
2465 /* Clear message list on next READY */
2466 GST_OBJECT_LOCK (bin);
2467 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2468 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2469 GST_OBJECT_UNLOCK (bin);
2470 if (current == GST_STATE_PAUSED)
2471 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2472 goto activate_failure;
2474 case GST_STATE_NULL:
2475 if (current == GST_STATE_READY)
2476 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2477 goto activate_failure;
2483 /* this flag is used to make the async state changes return immediately. We
2484 * don't want them to interfere with this state change */
2485 GST_OBJECT_LOCK (bin);
2486 bin->polling = TRUE;
2487 GST_OBJECT_UNLOCK (bin);
2489 /* iterate in state change order */
2490 it = gst_bin_iterate_sorted (bin);
2492 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2493 * Note how we don't reset this value when a resync happens, the reason being
2494 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2495 * even after a resync when the async element is gone */
2499 /* take base_time */
2500 base_time = gst_element_get_base_time (element);
2501 start_time = gst_element_get_start_time (element);
2503 have_no_preroll = FALSE;
2509 switch (gst_iterator_next (it, &data)) {
2510 case GST_ITERATOR_OK:
2514 child = GST_ELEMENT_CAST (data);
2516 /* set state and base_time now */
2517 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2521 case GST_STATE_CHANGE_SUCCESS:
2522 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2523 "child '%s' changed state to %d(%s) successfully",
2524 GST_ELEMENT_NAME (child), next,
2525 gst_element_state_get_name (next));
2527 case GST_STATE_CHANGE_ASYNC:
2529 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2530 "child '%s' is changing state asynchronously to %s",
2531 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2535 case GST_STATE_CHANGE_FAILURE:{
2538 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2539 "child '%s' failed to go to state %d(%s)",
2540 GST_ELEMENT_NAME (child),
2541 next, gst_element_state_get_name (next));
2543 /* Only fail if the child is still inside
2544 * this bin. It might've been removed already
2545 * because of the error by the bin subclass
2546 * to ignore the error. */
2547 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2548 if (parent == GST_OBJECT_CAST (element)) {
2549 /* element is still in bin, really error now */
2550 gst_object_unref (child);
2551 gst_object_unref (parent);
2554 /* child removed from bin, let the resync code redo the state
2556 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2557 "child '%s' was removed from the bin",
2558 GST_ELEMENT_NAME (child));
2561 gst_object_unref (parent);
2565 case GST_STATE_CHANGE_NO_PREROLL:
2566 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2567 "child '%s' changed state to %d(%s) successfully without preroll",
2568 GST_ELEMENT_NAME (child), next,
2569 gst_element_state_get_name (next));
2570 have_no_preroll = TRUE;
2573 g_assert_not_reached ();
2576 gst_object_unref (child);
2579 case GST_ITERATOR_RESYNC:
2580 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2581 gst_iterator_resync (it);
2584 case GST_ITERATOR_DONE:
2585 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2591 ret = parent_class->change_state (element, transition);
2592 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2595 if (have_no_preroll) {
2596 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2597 "we have NO_PREROLL elements %s -> NO_PREROLL",
2598 gst_element_state_change_return_get_name (ret));
2599 ret = GST_STATE_CHANGE_NO_PREROLL;
2600 } else if (have_async) {
2601 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2602 "we have ASYNC elements %s -> ASYNC",
2603 gst_element_state_change_return_get_name (ret));
2604 ret = GST_STATE_CHANGE_ASYNC;
2608 gst_iterator_free (it);
2610 GST_OBJECT_LOCK (bin);
2611 bin->polling = FALSE;
2612 /* it's possible that we did not get ASYNC from the children while the bin is
2613 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2614 * itself as the source. In that case we still want to check if the state
2615 * change completed. */
2616 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2617 /* no element returned ASYNC and there are no pending async_done messages,
2618 * we can just complete. */
2619 GST_DEBUG_OBJECT (bin, "no async elements");
2622 /* when we get here an ASYNC element was found */
2623 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2624 /* we ignore ASYNC state changes when we go to READY or NULL */
2625 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2626 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2630 GST_DEBUG_OBJECT (bin, "check async elements");
2631 /* check if all elements managed to commit their state already */
2632 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2633 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2634 * all the elements commited their state while we were doing the state
2635 * change. We will still return ASYNC for consistency but we commit the
2636 * state already so that a _get_state() will return immediately. */
2637 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2639 GST_DEBUG_OBJECT (bin, "async elements commited");
2640 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2644 bin->priv->pending_async_done = FALSE;
2645 GST_OBJECT_UNLOCK (bin);
2647 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2648 "done changing bin's state from %s to %s, now in %s, ret %s",
2649 gst_element_state_get_name (current),
2650 gst_element_state_get_name (next),
2651 gst_element_state_get_name (GST_STATE (element)),
2652 gst_element_state_change_return_get_name (ret));
2659 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2660 "failure (de)activating src pads");
2661 return GST_STATE_CHANGE_FAILURE;
2666 * This function is a utility event handler for seek events.
2667 * It will send the event to all sinks or sources depending on the
2670 * Applications are free to override this behaviour and
2671 * implement their own seek handler, but this will work for
2672 * pretty much all cases in practice.
2675 gst_bin_send_event (GstElement * element, GstEvent * event)
2677 GstBin *bin = GST_BIN_CAST (element);
2679 gboolean res = TRUE;
2680 gboolean done = FALSE;
2682 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2683 iter = gst_bin_iterate_sources (bin);
2684 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2685 GST_EVENT_TYPE_NAME (event));
2687 iter = gst_bin_iterate_sinks (bin);
2688 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2689 GST_EVENT_TYPE_NAME (event));
2695 switch (gst_iterator_next (iter, &data)) {
2696 case GST_ITERATOR_OK:
2700 gst_event_ref (event);
2701 child = GST_ELEMENT_CAST (data);
2702 res &= gst_element_send_event (child, event);
2703 GST_LOG_OBJECT (child, "After handling %s event: %d",
2704 GST_EVENT_TYPE_NAME (event), res);
2705 gst_object_unref (child);
2708 case GST_ITERATOR_RESYNC:
2709 gst_iterator_resync (iter);
2712 case GST_ITERATOR_DONE:
2715 case GST_ITERATOR_ERROR:
2716 g_assert_not_reached ();
2720 gst_iterator_free (iter);
2721 gst_event_unref (event);
2726 /* this is the function called by the threadpool. When async elements commit
2727 * their state, this function will attempt to bring the bin to the next state.
2730 gst_bin_continue_func (BinContinueData * data)
2733 GstState current, next, pending;
2734 GstStateChange transition;
2737 pending = data->pending;
2739 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2740 GST_STATE_LOCK (bin);
2742 GST_DEBUG_OBJECT (bin, "doing state continue");
2743 GST_OBJECT_LOCK (bin);
2745 /* if a new state change happened after this thread was scheduled, we return
2747 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2750 current = GST_STATE (bin);
2751 next = GST_STATE_GET_NEXT (current, pending);
2752 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2754 GST_STATE_NEXT (bin) = next;
2755 GST_STATE_PENDING (bin) = pending;
2757 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2758 GST_OBJECT_UNLOCK (bin);
2760 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2761 "continue state change %s to %s, final %s",
2762 gst_element_state_get_name (current),
2763 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2765 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2767 GST_STATE_UNLOCK (bin);
2768 GST_DEBUG_OBJECT (bin, "state continue done");
2770 gst_object_unref (bin);
2771 g_slice_free (BinContinueData, data);
2776 GST_OBJECT_UNLOCK (bin);
2777 GST_STATE_UNLOCK (bin);
2778 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2779 gst_object_unref (bin);
2780 g_slice_free (BinContinueData, data);
2785 static GstBusSyncReply
2786 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2788 GstBinClass *bclass;
2790 bclass = GST_BIN_GET_CLASS (bin);
2791 if (bclass->handle_message)
2792 bclass->handle_message (bin, message);
2794 gst_message_unref (message);
2796 return GST_BUS_DROP;
2800 bin_push_state_continue (BinContinueData * data)
2807 klass = GST_BIN_GET_CLASS (bin);
2809 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2810 g_thread_pool_push (klass->pool, data, NULL);
2813 /* an element started an async state change, if we were not busy with a state
2814 * change, we perform a lost state.
2815 * This function is called with the OBJECT lock.
2818 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2820 GstState old_state, new_state;
2822 GstMessage *amessage = NULL;
2824 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2827 /* get our toplevel state */
2828 toplevel = BIN_IS_TOPLEVEL (bin);
2830 /* prepare an ASYNC_START message, we always post the start message even if we
2831 * are busy with a state change or when we are NO_PREROLL. */
2833 /* non toplevel bin, prepare async-start for the parent */
2835 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2837 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2840 /* async starts are ignored when we are NO_PREROLL */
2841 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2842 goto was_no_preroll;
2844 old_state = GST_STATE (bin);
2846 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2847 * PLAYING after optionally redistributing the base_time. */
2848 if (old_state > GST_STATE_PAUSED)
2849 new_state = GST_STATE_PAUSED;
2851 new_state = old_state;
2853 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2854 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2855 gst_element_state_get_name (new_state));
2857 GST_STATE (bin) = new_state;
2858 GST_STATE_NEXT (bin) = new_state;
2859 GST_STATE_PENDING (bin) = new_state;
2860 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2861 GST_OBJECT_UNLOCK (bin);
2864 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2869 /* post our ASYNC_START. */
2870 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2871 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2873 GST_OBJECT_LOCK (bin);
2879 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2884 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2885 GST_OBJECT_UNLOCK (bin);
2890 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2891 GST_OBJECT_UNLOCK (bin);
2896 /* this function is called when there are no more async elements in the bin. We
2897 * post a state changed message and an ASYNC_DONE message.
2898 * This function is called with the OBJECT lock.
2901 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2902 gboolean flag_pending)
2904 GstState current, pending, target;
2905 GstStateChangeReturn old_ret;
2906 GstState old_state, old_next;
2907 gboolean toplevel, state_changed = FALSE;
2908 GstMessage *amessage = NULL;
2909 BinContinueData *cont = NULL;
2911 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2914 pending = GST_STATE_PENDING (bin);
2919 /* check if there is something to commit */
2920 if (pending == GST_STATE_VOID_PENDING)
2921 goto nothing_pending;
2923 old_ret = GST_STATE_RETURN (bin);
2924 GST_STATE_RETURN (bin) = ret;
2926 /* move to the next target state */
2927 target = GST_STATE_TARGET (bin);
2928 pending = GST_STATE_PENDING (bin) = target;
2930 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2932 old_state = GST_STATE (bin);
2933 /* this is the state we should go to next */
2934 old_next = GST_STATE_NEXT (bin);
2936 if (old_next != GST_STATE_PLAYING) {
2937 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2938 "committing state from %s to %s, old pending %s",
2939 gst_element_state_get_name (old_state),
2940 gst_element_state_get_name (old_next),
2941 gst_element_state_get_name (pending));
2943 /* update current state */
2944 current = GST_STATE (bin) = old_next;
2946 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2947 "setting state from %s to %s, pending %s",
2948 gst_element_state_get_name (old_state),
2949 gst_element_state_get_name (old_state),
2950 gst_element_state_get_name (pending));
2951 current = old_state;
2954 /* get our toplevel state */
2955 toplevel = BIN_IS_TOPLEVEL (bin);
2957 /* see if we reached the final state. If we are not toplevel, we also have to
2958 * stop here, the parent will continue our state. */
2959 if ((pending == current) || !toplevel) {
2960 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2961 "completed state change, pending VOID");
2963 /* mark VOID pending */
2964 pending = GST_STATE_VOID_PENDING;
2965 GST_STATE_PENDING (bin) = pending;
2966 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2968 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2969 "continue state change, pending %s",
2970 gst_element_state_get_name (pending));
2972 cont = g_slice_new (BinContinueData);
2974 /* ref to the bin */
2975 cont->bin = gst_object_ref (bin);
2976 /* cookie to detect concurrent state change */
2977 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2978 /* pending target state */
2979 cont->pending = pending;
2981 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2982 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2985 if (old_next != GST_STATE_PLAYING) {
2986 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2987 state_changed = TRUE;
2990 GST_OBJECT_UNLOCK (bin);
2992 if (state_changed) {
2993 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
2997 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2998 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
2999 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3002 GST_OBJECT_LOCK (bin);
3004 /* toplevel, start continue state */
3005 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3006 bin_push_state_continue (cont);
3008 GST_DEBUG_OBJECT (bin, "state change complete");
3009 GST_STATE_BROADCAST (bin);
3015 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3020 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3021 /* if we were busy with a state change and we are requested to flag a
3022 * pending async done, we do so here */
3024 bin->priv->pending_async_done = TRUE;
3029 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3035 bin_do_eos (GstBin * bin)
3040 GST_OBJECT_LOCK (bin);
3041 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3042 * we forward the EOS message to the parent bin or application
3044 eos = GST_STATE (bin) == GST_STATE_PLAYING
3045 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3046 && is_eos (bin, &seqnum);
3047 GST_OBJECT_UNLOCK (bin);
3050 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3052 GstMessage *tmessage;
3053 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3054 gst_message_set_seqnum (tmessage, seqnum);
3055 GST_DEBUG_OBJECT (bin,
3056 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3057 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3061 /* must be called with the object lock. This function releases the lock to post
3064 bin_do_message_forward (GstBin * bin, GstMessage * message)
3066 if (bin->priv->message_forward) {
3067 GstMessage *forwarded;
3069 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3070 GST_MESSAGE_TYPE_NAME (message));
3071 GST_OBJECT_UNLOCK (bin);
3073 /* we need to convert these messages to element messages so that our parent
3074 * bin can easily ignore them and so that the application can easily
3075 * distinguish between the internally forwarded and the real messages. */
3076 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3077 gst_structure_new ("GstBinForwarded",
3078 "message", GST_TYPE_MESSAGE, message, NULL));
3080 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3082 GST_OBJECT_LOCK (bin);
3086 /* handle child messages:
3088 * This method is called synchronously when a child posts a message on
3091 * GST_MESSAGE_EOS: This message is only posted by sinks
3092 * in the PLAYING state. If all sinks posted the EOS message, post
3095 * GST_MESSAGE_STATE_DIRTY: Deprecated
3097 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3098 * element posts segment_start twice, only the last message is kept.
3100 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3101 * with the segment_done message. If there are no more segment_start
3102 * messages, post segment_done message upwards.
3104 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3105 * Whenever someone performs a duration query on the bin, we store the
3106 * result so we can answer it quicker the next time. Any element that
3107 * changes its duration marks our cached values invalid.
3108 * This message is also posted upwards. This is currently disabled
3109 * because too many elements don't post DURATION messages when the
3112 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3113 * can no longer provide a clock. The default bin behaviour is to
3114 * check if the lost clock was the one provided by the bin. If so and
3115 * we are currently in the PLAYING state, we forward the message to
3117 * This message is also generated when we remove a clock provider from
3118 * a bin. If this message is received by the application, it should
3119 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3120 * and a new base_time distribution.
3122 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3123 * can provide a clock. This mostly happens when we add a new clock
3124 * provider to the bin. The default behaviour of the bin is to mark the
3125 * currently selected clock as dirty, which will perform a clock
3126 * recalculation the next time we are asked to provide a clock.
3127 * This message is never sent to the application but is forwarded to
3130 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3131 * the state of the element and the fact that the element will need a
3132 * new base_time. This message is not forwarded to the application.
3134 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3135 * element when it posted ASYNC_START. If all elements are done, post a
3136 * ASYNC_DONE message to the parent.
3138 * OTHER: post upwards.
3141 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3144 GstMessageType type;
3145 GstMessage *tmessage;
3148 src = GST_MESSAGE_SRC (message);
3149 type = GST_MESSAGE_TYPE (message);
3151 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3152 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3153 GST_MESSAGE_TYPE_NAME (message));
3156 case GST_MESSAGE_ERROR:
3158 GST_OBJECT_LOCK (bin);
3160 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3161 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3162 GST_STATE_BROADCAST (bin);
3163 GST_OBJECT_UNLOCK (bin);
3167 case GST_MESSAGE_EOS:
3170 /* collect all eos messages from the children */
3171 GST_OBJECT_LOCK (bin);
3172 bin_do_message_forward (bin, message);
3173 /* ref message for future use */
3174 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3175 GST_OBJECT_UNLOCK (bin);
3180 case GST_MESSAGE_STATE_DIRTY:
3182 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3185 gst_message_unref (message);
3188 case GST_MESSAGE_SEGMENT_START:{
3189 gboolean post = FALSE;
3193 gst_message_parse_segment_start (message, &format, &position);
3194 seqnum = gst_message_get_seqnum (message);
3196 GST_OBJECT_LOCK (bin);
3197 bin_do_message_forward (bin, message);
3198 /* if this is the first segment-start, post to parent but not to the
3200 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3201 (GST_OBJECT_PARENT (bin) != NULL)) {
3204 /* replace any previous segment_start message from this source
3205 * with the new segment start message */
3206 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3207 GST_OBJECT_UNLOCK (bin);
3209 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3211 gst_message_set_seqnum (tmessage, seqnum);
3213 /* post segment start with initial format and position. */
3214 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3216 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3220 case GST_MESSAGE_SEGMENT_DONE:
3222 gboolean post = FALSE;
3226 gst_message_parse_segment_done (message, &format, &position);
3227 seqnum = gst_message_get_seqnum (message);
3229 GST_OBJECT_LOCK (bin);
3230 bin_do_message_forward (bin, message);
3231 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3232 /* if there are no more segment_start messages, everybody posted
3233 * a segment_done and we can post one on the bus. */
3235 /* we don't care who still has a pending segment start */
3236 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3239 /* remove all old segment_done messages */
3240 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3242 GST_OBJECT_UNLOCK (bin);
3244 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3246 gst_message_set_seqnum (tmessage, seqnum);
3248 /* post segment done with latest format and position. */
3249 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3251 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3255 case GST_MESSAGE_DURATION:
3257 /* remove all cached duration messages, next time somebody asks
3258 * for duration, we will recalculate. */
3259 GST_OBJECT_LOCK (bin);
3260 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3261 GST_OBJECT_UNLOCK (bin);
3264 case GST_MESSAGE_CLOCK_LOST:
3266 GstClock **provided_clock_p;
3267 GstElement **clock_provider_p;
3268 gboolean playing, provided, forward;
3271 gst_message_parse_clock_lost (message, &clock);
3273 GST_OBJECT_LOCK (bin);
3274 bin->clock_dirty = TRUE;
3275 /* if we lost the clock that we provided, post to parent but
3276 * only if we are PLAYING. */
3277 provided = (clock == bin->provided_clock);
3278 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3279 forward = playing & provided;
3281 GST_DEBUG_OBJECT (bin,
3282 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3283 bin->provided_clock, bin->clock_provider);
3284 provided_clock_p = &bin->provided_clock;
3285 clock_provider_p = &bin->clock_provider;
3286 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3287 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3289 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3290 provided, playing, forward);
3291 GST_OBJECT_UNLOCK (bin);
3297 gst_message_unref (message);
3300 case GST_MESSAGE_CLOCK_PROVIDE:
3304 GST_OBJECT_LOCK (bin);
3305 bin->clock_dirty = TRUE;
3306 /* a new clock is available, post to parent but not
3307 * to the application */
3308 forward = GST_OBJECT_PARENT (bin) != NULL;
3309 GST_OBJECT_UNLOCK (bin);
3315 gst_message_unref (message);
3318 case GST_MESSAGE_ASYNC_START:
3320 gboolean new_base_time;
3323 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3324 src ? GST_OBJECT_NAME (src) : "(NULL)");
3326 gst_message_parse_async_start (message, &new_base_time);
3328 GST_OBJECT_LOCK (bin);
3329 bin_do_message_forward (bin, message);
3331 /* we ignore the message if we are going to <= READY */
3332 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3333 goto ignore_start_message;
3335 /* takes ownership of the message */
3336 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3338 bin_handle_async_start (bin, new_base_time);
3339 GST_OBJECT_UNLOCK (bin);
3342 ignore_start_message:
3344 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3345 gst_element_state_get_name (target));
3346 GST_OBJECT_UNLOCK (bin);
3347 gst_message_unref (message);
3351 case GST_MESSAGE_ASYNC_DONE:
3355 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3356 src ? GST_OBJECT_NAME (src) : "(NULL)");
3358 GST_OBJECT_LOCK (bin);
3359 bin_do_message_forward (bin, message);
3361 /* ignore messages if we are shutting down */
3362 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3363 goto ignore_done_message;
3365 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3366 /* if there are no more ASYNC_START messages, everybody posted
3367 * a ASYNC_DONE and we can post one on the bus. When checking, we
3368 * don't care who still has a pending ASYNC_START */
3369 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3370 /* nothing found, remove all old ASYNC_DONE messages */
3371 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3373 GST_DEBUG_OBJECT (bin, "async elements commited");
3374 /* when we get an async done message when a state change was busy, we
3375 * need to set the pending_done flag so that at the end of the state
3376 * change we can see if we need to verify pending async elements, hence
3377 * the TRUE argument here. */
3378 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3380 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3382 GST_OBJECT_UNLOCK (bin);
3385 ignore_done_message:
3387 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3388 gst_element_state_get_name (target));
3389 GST_OBJECT_UNLOCK (bin);
3390 gst_message_unref (message);
3394 case GST_MESSAGE_STRUCTURE_CHANGE:
3398 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3400 GST_OBJECT_LOCK (bin);
3402 /* while the pad is busy, avoid following it when doing state changes.
3403 * Don't update the cookie yet, we will do that after the structure
3404 * change finished and we are ready to inspect the new updated
3406 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3409 /* a pad link/unlink ended, signal the state change iterator that we
3410 * need to resync by updating the structure_cookie. */
3411 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3412 GST_MESSAGE_STRUCTURE_CHANGE);
3413 bin->priv->structure_cookie++;
3415 GST_OBJECT_UNLOCK (bin);
3418 gst_message_unref (message);
3429 /* Send all other messages upward */
3430 GST_DEBUG_OBJECT (bin, "posting message upward");
3431 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3436 /* generic struct passed to all query fold methods */
3445 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3446 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3448 /* for duration/position we collect all durations/positions and take
3449 * the MAX of all valid results */
3451 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3459 bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
3461 if (gst_element_query (item, fold->query)) {
3464 g_value_set_boolean (ret, TRUE);
3466 gst_query_parse_duration (fold->query, NULL, &duration);
3468 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3470 if (duration > fold->max)
3471 fold->max = duration;
3474 gst_object_unref (item);
3479 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3483 gst_query_parse_duration (fold->query, &format, NULL);
3484 /* store max in query result */
3485 gst_query_set_duration (fold->query, format, fold->max);
3487 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3489 #ifdef DURATION_CACHING
3491 GST_OBJECT_LOCK (bin);
3492 bin->messages = g_list_prepend (bin->messages,
3493 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3494 GST_OBJECT_UNLOCK (bin);
3499 bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
3501 if (gst_element_query (item, fold->query)) {
3504 g_value_set_boolean (ret, TRUE);
3506 gst_query_parse_position (fold->query, NULL, &position);
3508 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3510 if (position > fold->max)
3511 fold->max = position;
3514 gst_object_unref (item);
3519 bin_query_position_done (GstBin * bin, QueryFold * fold)
3523 gst_query_parse_position (fold->query, &format, NULL);
3524 /* store max in query result */
3525 gst_query_set_position (fold->query, format, fold->max);
3527 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3531 bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
3533 if (gst_element_query (item, fold->query)) {
3534 GstClockTime min, max;
3537 gst_query_parse_latency (fold->query, &live, &min, &max);
3539 GST_DEBUG_OBJECT (item,
3540 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3541 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3543 /* for the combined latency we collect the MAX of all min latencies and
3544 * the MIN of all max latencies */
3546 if (min > fold->min)
3548 if (fold->max == -1)
3550 else if (max < fold->max)
3552 if (fold->live == FALSE)
3556 g_value_set_boolean (ret, FALSE);
3557 GST_DEBUG_OBJECT (item, "failed query");
3560 gst_object_unref (item);
3565 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3567 /* store max in query result */
3568 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3570 GST_DEBUG_OBJECT (bin,
3571 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3572 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3576 /* generic fold, return first valid result */
3578 bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
3582 if ((res = gst_element_query (item, fold->query))) {
3583 g_value_set_boolean (ret, TRUE);
3584 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3587 gst_object_unref (item);
3589 /* and stop as soon as we have a valid result */
3594 gst_bin_query (GstElement * element, GstQuery * query)
3596 GstBin *bin = GST_BIN_CAST (element);
3598 gboolean res = FALSE;
3599 GstIteratorFoldFunction fold_func;
3600 QueryInitFunction fold_init = NULL;
3601 QueryDoneFunction fold_done = NULL;
3602 QueryFold fold_data;
3605 switch (GST_QUERY_TYPE (query)) {
3606 case GST_QUERY_DURATION:
3608 #ifdef DURATION_CACHING
3612 gst_query_parse_duration (query, &qformat, NULL);
3614 /* find cached duration query */
3615 GST_OBJECT_LOCK (bin);
3616 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3617 GstMessage *message = (GstMessage *) cached->data;
3619 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3620 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3624 gst_message_parse_duration (message, &format, &duration);
3626 /* if cached same format, copy duration in query result */
3627 if (format == qformat) {
3628 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3630 GST_OBJECT_UNLOCK (bin);
3632 gst_query_set_duration (query, qformat, duration);
3638 GST_OBJECT_UNLOCK (bin);
3640 /* no cached value found, iterate and collect durations */
3641 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3642 fold_init = bin_query_min_max_init;
3643 fold_done = bin_query_duration_done;
3646 case GST_QUERY_POSITION:
3648 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3649 fold_init = bin_query_min_max_init;
3650 fold_done = bin_query_position_done;
3653 case GST_QUERY_LATENCY:
3655 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3656 fold_init = bin_query_min_max_init;
3657 fold_done = bin_query_latency_done;
3662 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3666 fold_data.query = query;
3668 /* set the result of the query to FALSE initially */
3669 g_value_init (&ret, G_TYPE_BOOLEAN);
3670 g_value_set_boolean (&ret, res);
3672 iter = gst_bin_iterate_sinks (bin);
3673 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3674 query, GST_QUERY_TYPE_NAME (query));
3677 fold_init (bin, &fold_data);
3680 GstIteratorResult ires;
3682 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3685 case GST_ITERATOR_RESYNC:
3686 gst_iterator_resync (iter);
3688 fold_init (bin, &fold_data);
3689 g_value_set_boolean (&ret, res);
3691 case GST_ITERATOR_OK:
3692 case GST_ITERATOR_DONE:
3693 res = g_value_get_boolean (&ret);
3694 if (fold_done != NULL && res)
3695 fold_done (bin, &fold_data);
3703 gst_iterator_free (iter);
3705 #ifdef DURATION_CACHING
3708 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3714 compare_name (GstElement * element, const gchar * name)
3718 GST_OBJECT_LOCK (element);
3719 eq = strcmp (GST_ELEMENT_NAME (element), name);
3720 GST_OBJECT_UNLOCK (element);
3723 gst_object_unref (element);
3729 * gst_bin_get_by_name:
3731 * @name: the element name to search for
3733 * Gets the element with the given name from a bin. This
3734 * function recurses into child bins.
3736 * Returns NULL if no element with the given name is found in the bin.
3738 * MT safe. Caller owns returned reference.
3740 * Returns: (transfer full): the #GstElement with the given name, or NULL
3743 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3745 GstIterator *children;
3748 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3750 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3751 GST_ELEMENT_NAME (bin), name);
3753 children = gst_bin_iterate_recurse (bin);
3754 result = gst_iterator_find_custom (children,
3755 (GCompareFunc) compare_name, (gpointer) name);
3756 gst_iterator_free (children);
3758 return GST_ELEMENT_CAST (result);
3762 * gst_bin_get_by_name_recurse_up:
3764 * @name: the element name to search for
3766 * Gets the element with the given name from this bin. If the
3767 * element is not found, a recursion is performed on the parent bin.
3770 * - no element with the given name is found in the bin
3772 * MT safe. Caller owns returned reference.
3774 * Returns: (transfer full): the #GstElement with the given name, or NULL
3777 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3781 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3782 g_return_val_if_fail (name != NULL, NULL);
3784 result = gst_bin_get_by_name (bin, name);
3789 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3791 if (GST_IS_BIN (parent)) {
3792 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3794 gst_object_unref (parent);
3802 compare_interface (GstElement * element, gpointer interface)
3804 GType interface_type = (GType) interface;
3807 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3810 /* we did not find the element, need to release the ref
3811 * added by the iterator */
3812 gst_object_unref (element);
3819 * gst_bin_get_by_interface:
3821 * @iface: the #GType of an interface
3823 * Looks for an element inside the bin that implements the given
3824 * interface. If such an element is found, it returns the element.
3825 * You can cast this element to the given interface afterwards. If you want
3826 * all elements that implement the interface, use
3827 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3829 * MT safe. Caller owns returned reference.
3831 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3834 gst_bin_get_by_interface (GstBin * bin, GType iface)
3836 GstIterator *children;
3839 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3840 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3842 children = gst_bin_iterate_recurse (bin);
3843 result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3845 gst_iterator_free (children);
3847 return GST_ELEMENT_CAST (result);
3851 * gst_bin_iterate_all_by_interface:
3853 * @iface: the #GType of an interface
3855 * Looks for all elements inside the bin that implements the given
3856 * interface. You can safely cast all returned elements to the given interface.
3857 * The function recurses inside child bins. The iterator will yield a series
3858 * of #GstElement that should be unreffed after use.
3860 * Each element yielded by the iterator will have its refcount increased, so
3863 * MT safe. Caller owns returned value.
3865 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3866 * in the bin implementing the given interface, or NULL
3869 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3871 GstIterator *children;
3872 GstIterator *result;
3874 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3875 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3877 children = gst_bin_iterate_recurse (bin);
3878 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3884 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
3886 gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
3888 GstBin *bin = GST_BIN_CAST (object);
3889 xmlNodePtr childlist, elementnode;
3893 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
3894 GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
3896 childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
3898 GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
3899 GST_ELEMENT_NAME (bin), bin->numchildren);
3901 children = g_list_last (bin->children);
3903 child = GST_ELEMENT_CAST (children->data);
3904 elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
3905 gst_object_save_thyself (GST_OBJECT (child), elementnode);
3906 children = g_list_previous (children);
3912 gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
3914 GstBin *bin = GST_BIN_CAST (object);
3915 xmlNodePtr field = self->xmlChildrenNode;
3916 xmlNodePtr childlist;
3919 if (!strcmp ((char *) field->name, "children")) {
3920 GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
3921 GST_ELEMENT_NAME (object));
3922 childlist = field->xmlChildrenNode;
3924 if (!strcmp ((char *) childlist->name, "element")) {
3925 /* gst_xml_make_element will gst_bin_add() the element to ourself */
3926 gst_xml_make_element (childlist, GST_OBJECT (bin));
3928 childlist = childlist->next;
3932 field = field->next;
3934 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
3935 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
3937 #endif /* GST_DISABLE_LOADSAVE */