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"
166 #include "gsterror.h"
168 #include "gstindex.h"
169 #include "gstindexfactory.h"
170 #include "gstutils.h"
171 #include "gstchildproxy.h"
173 /* latency is by default enabled now.
174 * live-preroll and no-live-preroll in the environment var GST_COMPAT
175 * to enables or disable it respectively.
177 static gboolean enable_latency = TRUE;
179 GST_DEBUG_CATEGORY_STATIC (bin_debug);
180 #define GST_CAT_DEFAULT bin_debug
182 /* a bin is toplevel if it has no parent or when it is configured to behave like
184 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
186 #define GST_BIN_GET_PRIVATE(obj) \
187 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
189 struct _GstBinPrivate
191 gboolean asynchandling;
192 /* if we get an ASYNC_DONE message from ourselves, this means that the
193 * subclass will simulate ASYNC behaviour without having ASYNC children. When
194 * such an ASYNC_DONE message is posted while we are doing a state change, we
195 * have to process the message after finishing the state change even when no
196 * child returned GST_STATE_CHANGE_ASYNC. */
197 gboolean pending_async_done;
199 guint32 structure_cookie;
203 /* forward messages from our children */
204 gboolean message_forward;
216 static void gst_bin_dispose (GObject * object);
218 static void gst_bin_set_property (GObject * object, guint prop_id,
219 const GValue * value, GParamSpec * pspec);
220 static void gst_bin_get_property (GObject * object, guint prop_id,
221 GValue * value, GParamSpec * pspec);
223 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
224 GstStateChange transition);
225 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
226 GstState newstate, GstState pending);
227 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
228 GstState * state, GstState * pending, GstClockTime timeout);
229 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
230 gboolean flag_pending, gboolean reset_time);
231 static void bin_handle_async_start (GstBin * bin);
232 static void bin_push_state_continue (BinContinueData * data);
233 static void bin_do_eos (GstBin * bin);
235 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
236 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
238 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
239 static GstIndex *gst_bin_get_index_func (GstElement * element);
241 static GstClock *gst_bin_provide_clock_func (GstElement * element);
242 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
244 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
245 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
246 static GstBusSyncReply bin_bus_handler (GstBus * bus,
247 GstMessage * message, GstBin * bin);
248 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
250 static gboolean gst_bin_do_latency_func (GstBin * bin);
252 static void bin_remove_messages (GstBin * bin, GstObject * src,
253 GstMessageType types);
254 static void gst_bin_continue_func (BinContinueData * data);
255 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
256 static gint bin_element_is_src (GstElement * child, GstBin * bin);
258 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
260 /* Bin signals and properties */
269 #define DEFAULT_ASYNC_HANDLING FALSE
270 #define DEFAULT_MESSAGE_FORWARD FALSE
276 PROP_MESSAGE_FORWARD,
280 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
282 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
286 const gchar *compat; \
287 static const GInterfaceInfo iface_info = { \
288 gst_bin_child_proxy_init, \
292 g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
294 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
295 "debugging info for the 'bin' container element"); \
297 /* compatibility stuff */ \
298 compat = g_getenv ("GST_COMPAT"); \
299 if (compat != NULL) { \
300 if (strstr (compat, "no-live-preroll")) \
301 enable_latency = FALSE; \
302 else if (strstr (compat, "live-preroll")) \
303 enable_latency = TRUE; \
307 #define gst_bin_parent_class parent_class
308 G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT, _do_init);
311 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
317 bin = GST_BIN_CAST (child_proxy);
319 GST_OBJECT_LOCK (bin);
320 if ((res = g_list_nth_data (bin->children, index)))
321 gst_object_ref (res);
322 GST_OBJECT_UNLOCK (bin);
328 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
333 bin = GST_BIN_CAST (child_proxy);
335 GST_OBJECT_LOCK (bin);
336 num = bin->numchildren;
337 GST_OBJECT_UNLOCK (bin);
343 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
345 GstChildProxyInterface *iface = g_iface;
347 iface->get_children_count = gst_bin_child_proxy_get_children_count;
348 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
352 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
353 GValue * return_accu, const GValue * handler_return, gpointer dummy)
357 myboolean = g_value_get_boolean (handler_return);
358 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
359 g_value_set_boolean (return_accu, myboolean);
361 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
368 gst_bin_class_init (GstBinClass * klass)
370 GObjectClass *gobject_class;
371 GstElementClass *gstelement_class;
374 gobject_class = (GObjectClass *) klass;
375 gstelement_class = (GstElementClass *) klass;
377 g_type_class_add_private (klass, sizeof (GstBinPrivate));
379 gobject_class->set_property = gst_bin_set_property;
380 gobject_class->get_property = gst_bin_get_property;
383 * GstBin:async-handling
385 * If set to #TRUE, the bin will handle asynchronous state changes.
386 * This should be used only if the bin subclass is modifying the state
387 * of its children on its own.
391 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
392 g_param_spec_boolean ("async-handling", "Async Handling",
393 "The bin will handle Asynchronous state changes",
394 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
397 * GstBin::element-added:
399 * @element: the #GstElement that was added to the bin
401 * Will be emitted after the element was added to the bin.
403 gst_bin_signals[ELEMENT_ADDED] =
404 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
405 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
406 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
408 * GstBin::element-removed:
410 * @element: the #GstElement that was removed from the bin
412 * Will be emitted after the element was removed from the bin.
414 gst_bin_signals[ELEMENT_REMOVED] =
415 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
416 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
417 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
419 * GstBin::do-latency:
422 * Will be emitted when the bin needs to perform latency calculations. This
423 * signal is only emited for toplevel bins or when async-handling is
426 * Only one signal handler is invoked. If no signals are connected, the
427 * default handler is invoked, which will query and distribute the lowest
428 * possible latency to all sinks.
430 * Connect to this signal if the default latency calculations are not
431 * sufficient, like when you need different latencies for different sinks in
436 gst_bin_signals[DO_LATENCY] =
437 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
438 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
439 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
440 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
443 * GstBin:message-forward
445 * Forward all children messages, even those that would normally be filtered by
446 * the bin. This can be interesting when one wants to be notified of the EOS
447 * state of individual elements, for example.
449 * The messages are converted to an ELEMENT message with the bin as the
450 * source. The structure of the message is named 'GstBinForwarded' and contains
451 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
456 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
457 g_param_spec_boolean ("message-forward", "Message Forward",
458 "Forwards all children messages",
459 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
461 gobject_class->dispose = gst_bin_dispose;
463 gst_element_class_set_metadata (gstelement_class, "Generic bin",
465 "Simple container object",
466 "Erik Walthinsen <omega@cse.ogi.edu>,"
467 "Wim Taymans <wim.taymans@gmail.com>");
469 gstelement_class->change_state =
470 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
471 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
472 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
473 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
474 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
475 gstelement_class->provide_clock =
476 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
477 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
479 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
480 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
482 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
483 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
484 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
486 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
488 GST_DEBUG ("creating bin thread pool");
491 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
493 g_critical ("could alloc threadpool %s", err->message);
498 gst_bin_init (GstBin * bin)
502 bin->numchildren = 0;
503 bin->children = NULL;
504 bin->children_cookie = 0;
505 bin->messages = NULL;
506 bin->provided_clock = NULL;
507 bin->clock_dirty = FALSE;
509 /* Set up a bus for listening to child elements */
510 bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
511 bin->child_bus = bus;
512 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
514 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
516 bin->priv = GST_BIN_GET_PRIVATE (bin);
517 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
518 bin->priv->structure_cookie = 0;
519 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
523 gst_bin_dispose (GObject * object)
525 GstBin *bin = GST_BIN_CAST (object);
526 GstBus **child_bus_p = &bin->child_bus;
527 GstClock **provided_clock_p = &bin->provided_clock;
528 GstElement **clock_provider_p = &bin->clock_provider;
529 GstIndex **index_p = &bin->priv->index;
531 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
533 GST_OBJECT_LOCK (object);
534 gst_object_replace ((GstObject **) child_bus_p, NULL);
535 gst_object_replace ((GstObject **) provided_clock_p, NULL);
536 gst_object_replace ((GstObject **) clock_provider_p, NULL);
537 gst_object_replace ((GstObject **) index_p, NULL);
538 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
539 GST_OBJECT_UNLOCK (object);
541 while (bin->children) {
542 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
544 if (G_UNLIKELY (bin->children != NULL)) {
545 g_critical ("could not remove elements from bin '%s'",
546 GST_STR_NULL (GST_OBJECT_NAME (object)));
549 G_OBJECT_CLASS (parent_class)->dispose (object);
554 * @name: the name of the new bin
556 * Creates a new bin with the given name.
558 * Returns: (transfer full): a new #GstBin
561 gst_bin_new (const gchar * name)
563 return gst_element_factory_make ("bin", name);
567 gst_bin_set_property (GObject * object, guint prop_id,
568 const GValue * value, GParamSpec * pspec)
572 gstbin = GST_BIN_CAST (object);
575 case PROP_ASYNC_HANDLING:
576 GST_OBJECT_LOCK (gstbin);
577 gstbin->priv->asynchandling = g_value_get_boolean (value);
578 GST_OBJECT_UNLOCK (gstbin);
580 case PROP_MESSAGE_FORWARD:
581 GST_OBJECT_LOCK (gstbin);
582 gstbin->priv->message_forward = g_value_get_boolean (value);
583 GST_OBJECT_UNLOCK (gstbin);
586 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
592 gst_bin_get_property (GObject * object, guint prop_id,
593 GValue * value, GParamSpec * pspec)
597 gstbin = GST_BIN_CAST (object);
600 case PROP_ASYNC_HANDLING:
601 GST_OBJECT_LOCK (gstbin);
602 g_value_set_boolean (value, gstbin->priv->asynchandling);
603 GST_OBJECT_UNLOCK (gstbin);
605 case PROP_MESSAGE_FORWARD:
606 GST_OBJECT_LOCK (gstbin);
607 g_value_set_boolean (value, gstbin->priv->message_forward);
608 GST_OBJECT_UNLOCK (gstbin);
611 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
616 /* return the cached index */
618 gst_bin_get_index_func (GstElement * element)
623 bin = GST_BIN_CAST (element);
625 GST_OBJECT_LOCK (bin);
626 if ((result = bin->priv->index))
627 gst_object_ref (result);
628 GST_OBJECT_UNLOCK (bin);
633 /* set the index on all elements in this bin
638 gst_bin_set_index_func (GstElement * element, GstIndex * index)
644 GValue data = { 0, };
646 bin = GST_BIN_CAST (element);
648 GST_OBJECT_LOCK (bin);
649 old = bin->priv->index;
650 if (G_UNLIKELY (old == index))
653 gst_object_ref (index);
654 bin->priv->index = index;
655 GST_OBJECT_UNLOCK (bin);
658 gst_object_unref (old);
660 it = gst_bin_iterate_elements (bin);
662 /* set the index on all elements in the bin */
665 switch (gst_iterator_next (it, &data)) {
666 case GST_ITERATOR_OK:
668 GstElement *child = g_value_get_object (&data);
670 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
671 GST_ELEMENT_NAME (child));
672 gst_element_set_index (child, index);
674 g_value_reset (&data);
677 case GST_ITERATOR_RESYNC:
678 GST_DEBUG_OBJECT (bin, "iterator doing resync");
679 gst_iterator_resync (it);
682 case GST_ITERATOR_DONE:
683 GST_DEBUG_OBJECT (bin, "iterator done");
688 g_value_unset (&data);
689 gst_iterator_free (it);
694 GST_DEBUG_OBJECT (bin, "index was already set");
695 GST_OBJECT_UNLOCK (bin);
700 /* set the clock on all elements in this bin
705 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
711 GValue data = { 0, };
713 bin = GST_BIN_CAST (element);
715 it = gst_bin_iterate_elements (bin);
719 switch (gst_iterator_next (it, &data)) {
720 case GST_ITERATOR_OK:
722 GstElement *child = g_value_get_object (&data);
724 res &= gst_element_set_clock (child, clock);
726 g_value_reset (&data);
729 case GST_ITERATOR_RESYNC:
730 GST_DEBUG_OBJECT (bin, "iterator doing resync");
731 gst_iterator_resync (it);
735 case GST_ITERATOR_DONE:
736 GST_DEBUG_OBJECT (bin, "iterator done");
741 g_value_unset (&data);
742 gst_iterator_free (it);
745 res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
750 /* get the clock for this bin by asking all of the children in this bin
752 * The ref of the returned clock in increased so unref after usage.
754 * We loop the elements in state order and pick the last clock we can
755 * get. This makes sure we get a clock from the source.
760 gst_bin_provide_clock_func (GstElement * element)
762 GstClock *result = NULL;
763 GstElement *provider = NULL;
768 GstClock **provided_clock_p;
769 GstElement **clock_provider_p;
771 bin = GST_BIN_CAST (element);
773 GST_OBJECT_LOCK (bin);
774 if (!bin->clock_dirty)
777 GST_DEBUG_OBJECT (bin, "finding new clock");
779 it = gst_bin_sort_iterator_new (bin);
780 GST_OBJECT_UNLOCK (bin);
784 switch (gst_iterator_next (it, &val)) {
785 case GST_ITERATOR_OK:
787 GstElement *child = g_value_get_object (&val);
790 clock = gst_element_provide_clock (child);
792 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
793 clock, GST_ELEMENT_NAME (child));
795 gst_object_unref (result);
796 gst_object_unref (provider);
799 provider = gst_object_ref (child);
802 g_value_reset (&val);
805 case GST_ITERATOR_RESYNC:
806 gst_iterator_resync (it);
809 case GST_ITERATOR_DONE:
814 g_value_unset (&val);
815 gst_iterator_free (it);
817 GST_OBJECT_LOCK (bin);
818 if (!bin->clock_dirty) {
820 gst_object_unref (provider);
822 gst_object_unref (result);
828 provided_clock_p = &bin->provided_clock;
829 clock_provider_p = &bin->clock_provider;
830 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
831 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
832 bin->clock_dirty = FALSE;
833 GST_DEBUG_OBJECT (bin,
834 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
836 /* Provider is not being returned to caller, just the result */
838 gst_object_unref (provider);
839 GST_OBJECT_UNLOCK (bin);
845 if ((result = bin->provided_clock))
846 gst_object_ref (result);
847 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
848 GST_OBJECT_UNLOCK (bin);
855 * functions for manipulating cached messages
860 GstMessageType types;
863 /* check if a message is of given src and type */
865 message_check (GstMessage * message, MessageFind * target)
870 eq &= GST_MESSAGE_SRC (message) == target->src;
872 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
873 GST_LOG ("looking at message %p: %d", message, eq);
879 find_message (GstBin * bin, GstObject * src, GstMessageType types)
887 result = g_list_find_custom (bin->messages, &find,
888 (GCompareFunc) message_check);
891 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
892 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
895 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
896 #ifndef GST_DISABLE_GST_DEBUG
900 for (i = 0; i < 32; i++)
901 if (types & (1 << i))
902 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
910 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
913 * A message that is cached and has the same SRC and type is replaced
914 * by the given message.
917 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
923 if ((src = GST_MESSAGE_SRC (message))) {
924 /* first find the previous message posted by this element */
925 if ((previous = find_message (bin, src, types))) {
926 GstMessage *previous_msg;
928 /* if we found a previous message, replace it */
929 previous_msg = previous->data;
930 previous->data = message;
932 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
933 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
934 GST_MESSAGE_TYPE_NAME (message));
936 gst_message_unref (previous_msg);
938 /* keep new message */
939 bin->messages = g_list_prepend (bin->messages, message);
941 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
942 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
945 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
946 GST_MESSAGE_TYPE_NAME (message));
948 gst_message_unref (message);
953 /* with LOCK. Remove all messages of given types */
955 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
963 for (walk = bin->messages; walk; walk = next) {
964 GstMessage *message = (GstMessage *) walk->data;
966 next = g_list_next (walk);
968 if (message_check (message, &find) == 0) {
969 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
970 "deleting message %p of types 0x%08x", message, types);
971 bin->messages = g_list_delete_link (bin->messages, walk);
972 gst_message_unref (message);
974 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
975 "not deleting message %p of type 0x%08x", message,
976 GST_MESSAGE_TYPE (message));
982 /* Check if the bin is EOS. We do this by scanning all sinks and
983 * checking if they posted an EOS message.
985 * call with bin LOCK */
987 is_eos (GstBin * bin, guint32 * seqnum)
994 for (walk = bin->children; walk; walk = g_list_next (walk)) {
997 element = GST_ELEMENT_CAST (walk->data);
998 if (bin_element_is_sink (element, bin) == 0) {
999 /* check if element posted EOS */
1001 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
1002 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1003 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1006 GST_DEBUG ("sink '%s' did not post EOS yet",
1007 GST_ELEMENT_NAME (element));
1013 /* FIXME: Some tests (e.g. elements/capsfilter) use
1014 * pipelines with a dangling sinkpad but no sink element.
1015 * These tests assume that no EOS message is ever
1016 * posted on the bus so let's keep that behaviour.
1017 * In valid pipelines this doesn't make a difference.
1019 return result && n_eos > 0;
1023 unlink_pads (const GValue * item, gpointer user_data)
1028 pad = g_value_get_object (item);
1030 if ((peer = gst_pad_get_peer (pad))) {
1031 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1032 gst_pad_unlink (pad, peer);
1034 gst_pad_unlink (peer, pad);
1035 gst_object_unref (peer);
1039 /* vmethod that adds an element to a bin
1044 gst_bin_add_func (GstBin * bin, GstElement * element)
1048 gboolean is_sink, is_source, provides_clock, requires_clock;
1049 GstMessage *clock_message = NULL, *async_message = NULL;
1050 GstStateChangeReturn ret;
1052 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1054 /* we obviously can't add ourself to ourself */
1055 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1058 /* get the element name to make sure it is unique in this bin. */
1059 GST_OBJECT_LOCK (element);
1060 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1061 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1062 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1064 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1066 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1067 GST_OBJECT_UNLOCK (element);
1069 GST_OBJECT_LOCK (bin);
1071 /* then check to see if the element's name is already taken in the bin,
1072 * we can safely take the lock here. This check is probably bogus because
1073 * you can safely change the element name after this check and before setting
1074 * the object parent. The window is very small though... */
1075 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1076 goto duplicate_name;
1078 /* set the element's parent and add the element to the bin's list of children */
1079 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1080 GST_OBJECT_CAST (bin))))
1083 /* if we add a sink we become a sink */
1085 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1087 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
1090 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1092 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
1094 if (provides_clock) {
1095 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1097 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1098 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1100 if (requires_clock) {
1101 GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
1102 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1105 bin->children = g_list_prepend (bin->children, element);
1107 bin->children_cookie++;
1108 bin->priv->structure_cookie++;
1110 /* distribute the bus */
1111 gst_element_set_bus (element, bin->child_bus);
1113 /* propagate the current base_time, start_time and clock */
1114 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1115 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1116 /* it's possible that the element did not accept the clock but
1117 * that is not important right now. When the pipeline goes to PLAYING,
1118 * a new clock will be selected */
1119 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1120 /* set the cached index on the children */
1121 if (bin->priv->index)
1122 gst_element_set_index (element, bin->priv->index);
1124 ret = GST_STATE_RETURN (bin);
1125 /* no need to update the state if we are in error */
1126 if (ret == GST_STATE_CHANGE_FAILURE)
1127 goto no_state_recalc;
1129 /* update the bin state, the new element could have been an ASYNC or
1130 * NO_PREROLL element */
1131 ret = GST_STATE_RETURN (element);
1132 GST_DEBUG_OBJECT (bin, "added %s element",
1133 gst_element_state_change_return_get_name (ret));
1136 case GST_STATE_CHANGE_ASYNC:
1138 /* create message to track this aync element when it posts an async-done
1140 async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
1143 case GST_STATE_CHANGE_NO_PREROLL:
1144 /* ignore all async elements we might have and commit our state */
1145 bin_handle_async_done (bin, ret, FALSE, FALSE);
1147 case GST_STATE_CHANGE_FAILURE:
1154 GST_OBJECT_UNLOCK (bin);
1156 /* post the messages on the bus of the element so that the bin can handle
1159 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1162 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1164 /* unlink all linked pads */
1165 it = gst_element_iterate_pads (element);
1166 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1167 gst_iterator_free (it);
1169 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1173 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1174 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1178 /* ERROR handling here */
1181 GST_OBJECT_LOCK (bin);
1182 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1183 GST_OBJECT_UNLOCK (bin);
1188 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1189 elem_name, GST_ELEMENT_NAME (bin));
1190 GST_OBJECT_UNLOCK (bin);
1196 g_warning ("Element '%s' already has parent", elem_name);
1197 GST_OBJECT_UNLOCK (bin);
1206 * @element: (transfer full): the #GstElement to add
1208 * Adds the given element to the bin. Sets the element's parent, and thus
1209 * takes ownership of the element. An element can only be added to one bin.
1211 * If the element's pads are linked to other pads, the pads will be unlinked
1212 * before the element is added to the bin.
1215 * When you add an element to an already-running pipeline, you will have to
1216 * take care to set the state of the newly-added element to the desired
1217 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1218 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1219 * The bin or pipeline will not take care of this for you.
1224 * Returns: TRUE if the element could be added, FALSE if
1225 * the bin does not want to accept the element.
1228 gst_bin_add (GstBin * bin, GstElement * element)
1230 GstBinClass *bclass;
1233 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1234 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1236 bclass = GST_BIN_GET_CLASS (bin);
1238 if (G_UNLIKELY (bclass->add_element == NULL))
1241 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1242 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1243 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1245 result = bclass->add_element (bin, element);
1249 /* ERROR handling */
1252 g_warning ("adding elements to bin '%s' is not supported",
1253 GST_ELEMENT_NAME (bin));
1258 /* remove an element from the bin
1263 gst_bin_remove_func (GstBin * bin, GstElement * element)
1267 gboolean is_sink, is_source, provides_clock, requires_clock;
1268 gboolean othersink, othersource, otherprovider, otherrequirer, found;
1269 GstMessage *clock_message = NULL;
1270 GstClock **provided_clock_p;
1271 GstElement **clock_provider_p;
1273 gboolean other_async, this_async, have_no_preroll;
1274 GstStateChangeReturn ret;
1276 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1278 GST_OBJECT_LOCK (element);
1279 /* Check if the element is already being removed and immediately
1281 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element,
1282 GST_ELEMENT_FLAG_UNPARENTING)))
1283 goto already_removing;
1285 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_FLAG_UNPARENTING);
1286 /* grab element name so we can print it */
1287 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1288 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1289 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
1291 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1293 GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1294 GST_OBJECT_UNLOCK (element);
1296 /* unlink all linked pads */
1297 it = gst_element_iterate_pads (element);
1298 gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads, NULL);
1299 gst_iterator_free (it);
1301 GST_OBJECT_LOCK (bin);
1304 othersource = FALSE;
1305 otherprovider = FALSE;
1306 otherrequirer = FALSE;
1307 have_no_preroll = FALSE;
1308 /* iterate the elements, we collect which ones are async and no_preroll. We
1309 * also remove the element when we find it. */
1310 for (walk = bin->children; walk; walk = next) {
1311 GstElement *child = GST_ELEMENT_CAST (walk->data);
1313 next = g_list_next (walk);
1315 if (child == element) {
1317 /* remove the element */
1318 bin->children = g_list_delete_link (bin->children, walk);
1320 gboolean child_sink, child_source, child_provider, child_requirer;
1322 GST_OBJECT_LOCK (child);
1323 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1324 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1326 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1328 GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1329 /* when we remove a sink, check if there are other sinks. */
1330 if (is_sink && !othersink && child_sink)
1332 if (is_source && !othersource && child_source)
1334 if (provides_clock && !otherprovider && child_provider)
1335 otherprovider = TRUE;
1336 if (requires_clock && !otherrequirer && child_requirer)
1337 otherrequirer = TRUE;
1338 /* check if we have NO_PREROLL children */
1339 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1340 have_no_preroll = TRUE;
1341 GST_OBJECT_UNLOCK (child);
1345 /* the element must have been in the bin's list of children */
1346 if (G_UNLIKELY (!found))
1349 /* we now removed the element from the list of elements, increment the cookie
1350 * so that others can detect a change in the children list. */
1352 bin->children_cookie++;
1353 bin->priv->structure_cookie++;
1355 if (is_sink && !othersink) {
1356 /* we're not a sink anymore */
1357 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1358 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
1360 if (is_source && !othersource) {
1361 /* we're not a source anymore */
1362 GST_DEBUG_OBJECT (bin, "we removed the last source");
1363 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
1365 if (provides_clock && !otherprovider) {
1366 /* we're not a clock provider anymore */
1367 GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
1368 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
1370 if (requires_clock && !otherrequirer) {
1371 /* we're not a clock requirer anymore */
1372 GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
1373 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
1376 /* if the clock provider for this element is removed, we lost
1377 * the clock as well, we need to inform the parent of this
1378 * so that it can select a new clock */
1379 if (bin->clock_provider == element) {
1380 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1381 bin->clock_dirty = TRUE;
1383 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1384 provided_clock_p = &bin->provided_clock;
1385 clock_provider_p = &bin->clock_provider;
1386 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1387 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1390 /* remove messages for the element, if there was a pending ASYNC_START
1391 * message we must see if removing the element caused the bin to lose its
1394 other_async = FALSE;
1395 for (walk = bin->messages; walk; walk = next) {
1396 GstMessage *message = (GstMessage *) walk->data;
1397 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1400 next = g_list_next (walk);
1403 switch (GST_MESSAGE_TYPE (message)) {
1404 case GST_MESSAGE_ASYNC_START:
1410 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1412 case GST_MESSAGE_STRUCTURE_CHANGE:
1416 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1418 /* it's unlikely that this message is still in the list of messages
1419 * because this would mean that a link/unlink is busy in another thread
1420 * while we remove the element. We still have to remove the message
1421 * because we might not receive the done message anymore when the element
1422 * is removed from the bin. */
1423 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1424 if (owner == element)
1435 /* delete all message types */
1436 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1437 message, elem_name);
1438 bin->messages = g_list_delete_link (bin->messages, walk);
1439 gst_message_unref (message);
1443 /* get last return */
1444 ret = GST_STATE_RETURN (bin);
1446 /* no need to update the state if we are in error */
1447 if (ret == GST_STATE_CHANGE_FAILURE)
1448 goto no_state_recalc;
1450 if (!other_async && this_async) {
1451 /* all other elements were not async and we removed the async one,
1452 * handle the async-done case because we are not async anymore now. */
1453 GST_DEBUG_OBJECT (bin,
1454 "we removed the last async element, have no_preroll %d",
1457 /* the current state return of the bin depends on if there are no_preroll
1458 * elements in the pipeline or not */
1459 if (have_no_preroll)
1460 ret = GST_STATE_CHANGE_NO_PREROLL;
1462 ret = GST_STATE_CHANGE_SUCCESS;
1464 bin_handle_async_done (bin, ret, FALSE, FALSE);
1466 GST_DEBUG_OBJECT (bin,
1467 "recalc state preroll: %d, other async: %d, this async %d",
1468 have_no_preroll, other_async, this_async);
1470 if (have_no_preroll) {
1471 ret = GST_STATE_CHANGE_NO_PREROLL;
1472 } else if (other_async) {
1473 /* there are other async elements and we were not doing an async state
1474 * change, change our pending state and go async */
1475 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1476 GST_STATE_NEXT (bin) = GST_STATE (bin);
1477 GST_STATE_PENDING (bin) = GST_STATE (bin);
1479 ret = GST_STATE_CHANGE_ASYNC;
1481 GST_STATE_RETURN (bin) = ret;
1484 GST_OBJECT_UNLOCK (bin);
1487 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1489 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1493 gst_element_set_bus (element, NULL);
1495 /* Clear the clock we provided to the element */
1496 gst_element_set_clock (element, NULL);
1498 /* we ref here because after the _unparent() the element can be disposed
1499 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1500 gst_object_ref (element);
1501 gst_object_unparent (GST_OBJECT_CAST (element));
1503 GST_OBJECT_LOCK (element);
1504 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_FLAG_UNPARENTING);
1505 GST_OBJECT_UNLOCK (element);
1507 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1508 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1510 /* element is really out of our control now */
1511 gst_object_unref (element);
1515 /* ERROR handling */
1518 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1519 GST_ELEMENT_NAME (bin));
1520 GST_OBJECT_UNLOCK (bin);
1526 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1527 GST_OBJECT_UNLOCK (element);
1535 * @element: (transfer none): the #GstElement to remove
1537 * Removes the element from the bin, unparenting it as well.
1538 * Unparenting the element means that the element will be dereferenced,
1539 * so if the bin holds the only reference to the element, the element
1540 * will be freed in the process of removing it from the bin. If you
1541 * want the element to still exist after removing, you need to call
1542 * gst_object_ref() before removing it from the bin.
1544 * If the element's pads are linked to other pads, the pads will be unlinked
1545 * before the element is removed from the bin.
1549 * Returns: TRUE if the element could be removed, FALSE if
1550 * the bin does not want to remove the element.
1553 gst_bin_remove (GstBin * bin, GstElement * element)
1555 GstBinClass *bclass;
1558 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1559 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1561 bclass = GST_BIN_GET_CLASS (bin);
1563 if (G_UNLIKELY (bclass->remove_element == NULL))
1566 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1567 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1569 result = bclass->remove_element (bin, element);
1573 /* ERROR handling */
1576 g_warning ("removing elements from bin '%s' is not supported",
1577 GST_ELEMENT_NAME (bin));
1583 * gst_bin_iterate_elements:
1586 * Gets an iterator for the elements in this bin.
1588 * Each element yielded by the iterator will have its refcount increased, so
1591 * MT safe. Caller owns returned value.
1593 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1596 gst_bin_iterate_elements (GstBin * bin)
1598 GstIterator *result;
1600 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1602 GST_OBJECT_LOCK (bin);
1603 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1604 GST_OBJECT_GET_LOCK (bin),
1605 &bin->children_cookie, &bin->children, (GObject *) bin, NULL);
1606 GST_OBJECT_UNLOCK (bin);
1611 static GstIteratorItem
1612 iterate_child_recurse (GstIterator * it, const GValue * item)
1614 GstElement *child = g_value_get_object (item);
1616 if (GST_IS_BIN (child)) {
1617 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1619 gst_iterator_push (it, other);
1621 return GST_ITERATOR_ITEM_PASS;
1625 * gst_bin_iterate_recurse:
1628 * Gets an iterator for the elements in this bin.
1629 * This iterator recurses into GstBin children.
1631 * Each element yielded by the iterator will have its refcount increased, so
1634 * MT safe. Caller owns returned value.
1636 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1639 gst_bin_iterate_recurse (GstBin * bin)
1641 GstIterator *result;
1643 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1645 GST_OBJECT_LOCK (bin);
1646 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1647 GST_OBJECT_GET_LOCK (bin),
1648 &bin->children_cookie,
1650 (GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
1651 GST_OBJECT_UNLOCK (bin);
1656 /* returns 0 when TRUE because this is a GCompareFunc */
1659 bin_element_is_sink (GstElement * child, GstBin * bin)
1663 /* we lock the child here for the remainder of the function to
1664 * get its name and flag safely. */
1665 GST_OBJECT_LOCK (child);
1666 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
1668 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1669 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1671 GST_OBJECT_UNLOCK (child);
1672 return is_sink ? 0 : 1;
1676 sink_iterator_filter (const GValue * vchild, GValue * vbin)
1678 GstBin *bin = g_value_get_object (vbin);
1679 GstElement *child = g_value_get_object (vchild);
1681 return (bin_element_is_sink (child, bin));
1685 * gst_bin_iterate_sinks:
1688 * Gets an iterator for all elements in the bin that have the
1689 * #GST_ELEMENT_FLAG_SINK flag set.
1691 * Each element yielded by the iterator will have its refcount increased, so
1694 * MT safe. Caller owns returned value.
1696 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1699 gst_bin_iterate_sinks (GstBin * bin)
1701 GstIterator *children;
1702 GstIterator *result;
1703 GValue vbin = { 0, };
1705 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1707 g_value_init (&vbin, GST_TYPE_BIN);
1708 g_value_set_object (&vbin, bin);
1710 children = gst_bin_iterate_elements (bin);
1711 result = gst_iterator_filter (children,
1712 (GCompareFunc) sink_iterator_filter, &vbin);
1714 g_value_unset (&vbin);
1719 /* returns 0 when TRUE because this is a GCompareFunc */
1722 bin_element_is_src (GstElement * child, GstBin * bin)
1726 /* we lock the child here for the remainder of the function to
1727 * get its name and other info safely. */
1728 GST_OBJECT_LOCK (child);
1729 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
1731 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1732 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1734 GST_OBJECT_UNLOCK (child);
1735 return is_src ? 0 : 1;
1739 src_iterator_filter (const GValue * vchild, GValue * vbin)
1741 GstBin *bin = g_value_get_object (vbin);
1742 GstElement *child = g_value_get_object (vchild);
1744 return (bin_element_is_src (child, bin));
1748 * gst_bin_iterate_sources:
1751 * Gets an iterator for all elements in the bin that have the
1752 * #GST_ELEMENT_FLAG_SOURCE flag set.
1754 * Each element yielded by the iterator will have its refcount increased, so
1757 * MT safe. Caller owns returned value.
1759 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1762 gst_bin_iterate_sources (GstBin * bin)
1764 GstIterator *children;
1765 GstIterator *result;
1766 GValue vbin = { 0, };
1768 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1770 g_value_init (&vbin, GST_TYPE_BIN);
1771 g_value_set_object (&vbin, bin);
1773 children = gst_bin_iterate_elements (bin);
1774 result = gst_iterator_filter (children,
1775 (GCompareFunc) src_iterator_filter, &vbin);
1777 g_value_unset (&vbin);
1785 static GstStateChangeReturn
1786 gst_bin_get_state_func (GstElement * element, GstState * state,
1787 GstState * pending, GstClockTime timeout)
1789 GstStateChangeReturn ret;
1791 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1794 GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
1800 /***********************************************
1801 * Topologically sorted iterator
1802 * see http://en.wikipedia.org/wiki/Topological_sorting
1804 * For each element in the graph, an entry is kept in a HashTable
1805 * with its number of srcpad connections (degree).
1806 * We then change state of all elements without dependencies
1807 * (degree 0) and decrement the degree of all elements connected
1808 * on the sinkpads. When an element reaches degree 0, its state is
1810 * When all elements are handled the algorithm stops.
1812 typedef struct _GstBinSortIterator
1815 GQueue queue; /* elements queued for state change */
1816 GstBin *bin; /* bin we iterate */
1817 gint mode; /* adding or removing dependency */
1818 GstElement *best; /* next element with least dependencies */
1819 gint best_deg; /* best degree */
1820 GHashTable *hash; /* hashtable with element dependencies */
1821 gboolean dirty; /* we detected structure change */
1822 } GstBinSortIterator;
1825 gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
1826 GstBinSortIterator * copy)
1828 GHashTableIter iter;
1829 gpointer key, value;
1831 copy->queue = it->queue;
1832 g_queue_foreach (©->queue, (GFunc) gst_object_ref, NULL);
1834 copy->bin = gst_object_ref (it->bin);
1836 copy->best = gst_object_ref (it->best);
1838 copy->hash = g_hash_table_new (NULL, NULL);
1839 g_hash_table_iter_init (&iter, it->hash);
1840 while (g_hash_table_iter_next (&iter, &key, &value))
1841 g_hash_table_insert (copy->hash, key, value);
1844 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1845 #define HASH_SET_DEGREE(bit, elem, deg) \
1846 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1847 #define HASH_GET_DEGREE(bit, elem) \
1848 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1850 /* add element to queue of next elements in the iterator.
1851 * We push at the tail to give higher priority elements a
1854 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1856 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1857 GST_ELEMENT_NAME (element));
1858 gst_object_ref (element);
1859 g_queue_push_tail (&bit->queue, element);
1860 HASH_SET_DEGREE (bit, element, -1);
1864 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1868 if ((find = g_queue_find (&bit->queue, element))) {
1869 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1870 GST_ELEMENT_NAME (element));
1872 g_queue_delete_link (&bit->queue, find);
1873 gst_object_unref (element);
1875 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1876 GST_ELEMENT_NAME (element));
1880 /* clear the queue, unref all objects as we took a ref when
1881 * we added them to the queue */
1883 clear_queue (GQueue * queue)
1887 while ((p = g_queue_pop_head (queue)))
1888 gst_object_unref (p);
1891 /* set all degrees to 0. Elements marked as a sink are
1892 * added to the queue immediately. Since we only look at the SINK flag of the
1893 * element, it is possible that we add non-sinks to the queue. These will be
1894 * removed from the queue again when we can prove that it provides data for some
1897 reset_degree (GstElement * element, GstBinSortIterator * bit)
1901 /* sinks are added right away */
1902 GST_OBJECT_LOCK (element);
1903 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
1904 GST_OBJECT_UNLOCK (element);
1907 add_to_queue (bit, element);
1909 /* others are marked with 0 and handled when sinks are done */
1910 HASH_SET_DEGREE (bit, element, 0);
1914 /* adjust the degree of all elements connected to the given
1915 * element. If a degree of an element drops to 0, it is
1916 * added to the queue of elements to schedule next.
1918 * We have to make sure not to cross the bin boundary this element
1922 update_degree (GstElement * element, GstBinSortIterator * bit)
1924 gboolean linked = FALSE;
1926 GST_OBJECT_LOCK (element);
1927 /* don't touch degree if element has no sinkpads */
1928 if (element->numsinkpads != 0) {
1929 /* loop over all sinkpads, decrement degree for all connected
1930 * elements in this bin */
1933 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1936 pad = GST_PAD_CAST (pads->data);
1938 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1939 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1940 GST_MESSAGE_STRUCTURE_CHANGE))) {
1941 /* mark the iterator as dirty because we won't be updating the degree
1942 * of the peer parent now. This would result in the 'loop detected'
1943 * later on because the peer parent element could become the best next
1944 * element with a degree > 0. We will simply continue our state
1945 * changes and we'll eventually resync when the unlink completed and
1946 * the iterator cookie is updated. */
1951 if ((peer = gst_pad_get_peer (pad))) {
1952 GstElement *peer_element;
1954 if ((peer_element = gst_pad_get_parent_element (peer))) {
1955 GST_OBJECT_LOCK (peer_element);
1956 /* check that we don't go outside of this bin */
1957 if (GST_OBJECT_CAST (peer_element)->parent ==
1958 GST_OBJECT_CAST (bit->bin)) {
1959 gint old_deg, new_deg;
1961 old_deg = HASH_GET_DEGREE (bit, peer_element);
1963 /* check to see if we added an element as sink that was not really a
1964 * sink because it was connected to some other element. */
1965 if (old_deg == -1) {
1966 remove_from_queue (bit, peer_element);
1969 new_deg = old_deg + bit->mode;
1971 GST_DEBUG_OBJECT (bit->bin,
1972 "change element %s, degree %d->%d, linked to %s",
1973 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1974 GST_ELEMENT_NAME (element));
1976 /* update degree, it is possible that an element was in 0 and
1977 * reaches -1 here. This would mean that the element had no sinkpads
1978 * but became linked while the state change was happening. We will
1979 * resync on this with the structure change message. */
1981 /* degree hit 0, add to queue */
1982 add_to_queue (bit, peer_element);
1984 HASH_SET_DEGREE (bit, peer_element, new_deg);
1988 GST_OBJECT_UNLOCK (peer_element);
1989 gst_object_unref (peer_element);
1991 gst_object_unref (peer);
1996 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1997 GST_ELEMENT_NAME (element));
1999 GST_OBJECT_UNLOCK (element);
2002 /* find the next best element not handled yet. This is the one
2003 * with the lowest non-negative degree */
2005 find_element (GstElement * element, GstBinSortIterator * bit)
2009 /* element is already handled */
2010 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
2013 /* first element or element with smaller degree */
2014 if (bit->best == NULL || bit->best_deg > degree) {
2015 bit->best = element;
2016 bit->best_deg = degree;
2020 /* get next element in iterator. the returned element has the
2021 * refcount increased */
2022 static GstIteratorResult
2023 gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
2026 GstBin *bin = bit->bin;
2028 /* empty queue, we have to find a next best element */
2029 if (g_queue_is_empty (&bit->queue)) {
2031 bit->best_deg = G_MAXINT;
2032 g_list_foreach (bin->children, (GFunc) find_element, bit);
2033 if ((best = bit->best)) {
2034 /* when we detected an unlink, don't warn because our degrees might be
2035 * screwed up. We will resync later */
2036 if (bit->best_deg != 0 && !bit->dirty) {
2037 /* we don't fail on this one yet */
2038 GST_WARNING_OBJECT (bin, "loop dected in graph");
2039 g_warning ("loop detected in the graph of bin '%s'!!",
2040 GST_ELEMENT_NAME (bin));
2042 /* best unhandled element, schedule as next element */
2043 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2044 GST_ELEMENT_NAME (best));
2045 HASH_SET_DEGREE (bit, best, -1);
2046 g_value_set_object (result, best);
2048 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2049 /* no more unhandled elements, we are done */
2050 return GST_ITERATOR_DONE;
2053 /* everything added to the queue got reffed */
2054 best = g_queue_pop_head (&bit->queue);
2055 g_value_set_object (result, best);
2056 gst_object_unref (best);
2059 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
2060 /* update degrees of linked elements */
2061 update_degree (best, bit);
2063 return GST_ITERATOR_OK;
2066 /* clear queues, recalculate the degrees and restart. */
2068 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2070 GstBin *bin = bit->bin;
2072 GST_DEBUG_OBJECT (bin, "resync");
2074 clear_queue (&bit->queue);
2076 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2077 /* calc degrees, incrementing */
2079 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2080 /* for the rest of the function we decrement the degrees */
2084 /* clear queues, unref bin and free iterator. */
2086 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2088 GstBin *bin = bit->bin;
2090 GST_DEBUG_OBJECT (bin, "free");
2091 clear_queue (&bit->queue);
2092 g_hash_table_destroy (bit->hash);
2093 gst_object_unref (bin);
2096 /* should be called with the bin LOCK held */
2097 static GstIterator *
2098 gst_bin_sort_iterator_new (GstBin * bin)
2100 GstBinSortIterator *result;
2102 /* we don't need an ItemFunction because we ref the items in the _next
2104 result = (GstBinSortIterator *)
2105 gst_iterator_new (sizeof (GstBinSortIterator),
2107 GST_OBJECT_GET_LOCK (bin),
2108 &bin->priv->structure_cookie,
2109 (GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
2110 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2111 (GstIteratorItemFunction) NULL,
2112 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2113 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2114 g_queue_init (&result->queue);
2115 result->hash = g_hash_table_new (NULL, NULL);
2116 gst_object_ref (bin);
2118 gst_bin_sort_iterator_resync (result);
2120 return (GstIterator *) result;
2124 * gst_bin_iterate_sorted:
2127 * Gets an iterator for the elements in this bin in topologically
2128 * sorted order. This means that the elements are returned from
2129 * the most downstream elements (sinks) to the sources.
2131 * This function is used internally to perform the state changes
2132 * of the bin elements and for clock selection.
2134 * Each element yielded by the iterator will have its refcount increased, so
2137 * MT safe. Caller owns returned value.
2139 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2142 gst_bin_iterate_sorted (GstBin * bin)
2144 GstIterator *result;
2146 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2148 GST_OBJECT_LOCK (bin);
2149 result = gst_bin_sort_iterator_new (bin);
2150 GST_OBJECT_UNLOCK (bin);
2155 static GstStateChangeReturn
2156 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2157 GstClockTime base_time, GstClockTime start_time, GstState current,
2160 GstStateChangeReturn ret;
2161 GstState pending, child_current, child_pending;
2165 GST_STATE_LOCK (element);
2167 GST_OBJECT_LOCK (element);
2168 /* set base_time and start time on child */
2169 GST_ELEMENT_START_TIME (element) = start_time;
2170 element->base_time = base_time;
2171 /* peel off the locked flag */
2172 locked = GST_ELEMENT_IS_LOCKED_STATE (element);
2173 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2174 ret = GST_STATE_RETURN (element);
2175 child_current = GST_STATE (element);
2176 child_pending = GST_STATE_PENDING (element);
2177 GST_OBJECT_UNLOCK (element);
2179 /* skip locked elements */
2180 if (G_UNLIKELY (locked))
2183 /* if the element was no preroll, just start changing the state regardless
2184 * if it had async elements (in the case of a bin) because they won't preroll
2186 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2187 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2191 GST_OBJECT_LOCK (bin);
2192 pending = GST_STATE_PENDING (bin);
2194 /* Try not to change the state of elements that are already in the state we're
2196 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2197 (child_pending == GST_STATE_VOID_PENDING &&
2198 ((pending > child_current && next > child_current) ||
2199 (pending < child_current && next < child_current)))))
2202 /* the element was busy with an upwards async state change, we must wait for
2203 * an ASYNC_DONE message before we attemp to change the state. */
2205 find_message (bin, GST_OBJECT_CAST (element),
2206 GST_MESSAGE_ASYNC_START))) {
2207 #ifndef GST_DISABLE_GST_DEBUG
2208 GstMessage *message = GST_MESSAGE_CAST (found->data);
2210 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2211 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2213 /* only wait for upward state changes */
2214 if (next > current) {
2215 /* We found an async element check if we can force its state to change or
2216 * if we have to wait for it to preroll. */
2217 if (G_UNLIKELY (!enable_latency)) {
2218 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2219 "\tto preroll in order to perform correct latency calculations.\n"
2220 "\tPlease verify that the application continues to work correctly by\n"
2221 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2222 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2229 GST_OBJECT_UNLOCK (bin);
2232 GST_DEBUG_OBJECT (bin,
2233 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2234 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2235 GST_TIME_ARGS (base_time));
2238 ret = gst_element_set_state (element, next);
2240 GST_STATE_UNLOCK (element);
2246 GST_DEBUG_OBJECT (element,
2247 "element is locked, return previous return %s",
2248 gst_element_state_change_return_get_name (ret));
2249 GST_STATE_UNLOCK (element);
2254 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2255 GST_OBJECT_UNLOCK (bin);
2256 GST_STATE_UNLOCK (element);
2257 return GST_STATE_CHANGE_ASYNC;
2261 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2262 "skipping transition from %s to %s, since bin pending"
2263 " is %s : last change state return follows",
2264 gst_element_state_get_name (child_current),
2265 gst_element_state_get_name (next),
2266 gst_element_state_get_name (pending));
2267 GST_OBJECT_UNLOCK (bin);
2268 GST_STATE_UNLOCK (element);
2273 /* gst_iterator_fold functions for pads_activate
2274 * Stop the iterator if activating one pad failed. */
2276 activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
2278 GstPad *pad = g_value_get_object (vpad);
2279 gboolean cont = TRUE;
2281 if (!(cont = gst_pad_set_active (pad, *active)))
2282 g_value_set_boolean (ret, FALSE);
2287 /* returns false on error or early cutout of the fold, true if all
2288 * pads in @iter were (de)activated successfully. */
2290 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2292 GstIteratorResult ires;
2295 /* no need to unset this later, it's just a boolean */
2296 g_value_init (&ret, G_TYPE_BOOLEAN);
2297 g_value_set_boolean (&ret, TRUE);
2300 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2303 case GST_ITERATOR_RESYNC:
2304 /* need to reset the result again */
2305 g_value_set_boolean (&ret, TRUE);
2306 gst_iterator_resync (iter);
2308 case GST_ITERATOR_DONE:
2309 /* all pads iterated, return collected value */
2312 /* iterator returned _ERROR or premature end with _OK,
2313 * mark an error and exit */
2314 g_value_set_boolean (&ret, FALSE);
2319 /* return collected value */
2320 return g_value_get_boolean (&ret);
2323 /* is called with STATE_LOCK
2326 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2331 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2333 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2334 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2335 gst_iterator_free (iter);
2336 if (G_UNLIKELY (!fold_ok))
2339 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2346 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2352 * gst_bin_recalculate_latency:
2355 * Query @bin for the current latency using and reconfigures this latency to all the
2356 * elements with a LATENCY event.
2358 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2359 * is posted on the bus.
2361 * This function simply emits the 'do-latency' signal so any custom latency
2362 * calculations will be performed.
2364 * Returns: %TRUE if the latency could be queried and reconfigured.
2369 gst_bin_recalculate_latency (GstBin * bin)
2373 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2374 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2380 gst_bin_do_latency_func (GstBin * bin)
2383 GstElement *element;
2384 GstClockTime min_latency, max_latency;
2387 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2389 element = GST_ELEMENT_CAST (bin);
2391 GST_DEBUG_OBJECT (element, "querying latency");
2393 query = gst_query_new_latency ();
2394 if ((res = gst_element_query (element, query))) {
2397 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2399 GST_DEBUG_OBJECT (element,
2400 "got min latency %" GST_TIME_FORMAT ", max latency %"
2401 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2402 GST_TIME_ARGS (max_latency), live);
2404 if (max_latency < min_latency) {
2405 /* this is an impossible situation, some parts of the pipeline might not
2406 * work correctly. We post a warning for now. */
2407 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2408 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2409 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2410 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2413 /* configure latency on elements */
2414 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2416 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2417 GST_TIME_ARGS (min_latency));
2419 GST_WARNING_OBJECT (element,
2420 "did not really configure latency of %" GST_TIME_FORMAT,
2421 GST_TIME_ARGS (min_latency));
2424 /* this is not a real problem, we just don't configure any latency. */
2425 GST_WARNING_OBJECT (element, "failed to query latency");
2427 gst_query_unref (query);
2433 gst_bin_state_changed (GstElement * element, GstState oldstate,
2434 GstState newstate, GstState pending)
2436 GstElementClass *pklass = (GstElementClass *) parent_class;
2438 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2439 bin_do_eos (GST_BIN_CAST (element));
2441 if (pklass->state_changed)
2442 pklass->state_changed (element, oldstate, newstate, pending);
2445 static GstStateChangeReturn
2446 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2449 GstStateChangeReturn ret;
2450 GstState current, next;
2451 gboolean have_async;
2452 gboolean have_no_preroll;
2453 GstClockTime base_time, start_time;
2456 GValue data = { 0, };
2458 /* we don't need to take the STATE_LOCK, it is already taken */
2459 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2460 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2462 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2463 "changing state of children from %s to %s",
2464 gst_element_state_get_name (current), gst_element_state_get_name (next));
2466 bin = GST_BIN_CAST (element);
2469 case GST_STATE_PLAYING:
2473 GST_OBJECT_LOCK (bin);
2474 toplevel = BIN_IS_TOPLEVEL (bin);
2475 GST_OBJECT_UNLOCK (bin);
2478 gst_bin_recalculate_latency (bin);
2481 case GST_STATE_PAUSED:
2482 /* Clear EOS list on next PAUSED */
2483 GST_OBJECT_LOCK (bin);
2484 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2485 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2486 bin->priv->posted_eos = FALSE;
2487 GST_OBJECT_UNLOCK (bin);
2488 if (current == GST_STATE_READY)
2489 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2490 goto activate_failure;
2492 case GST_STATE_READY:
2493 /* Clear message list on next READY */
2494 GST_OBJECT_LOCK (bin);
2495 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2496 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2497 GST_OBJECT_UNLOCK (bin);
2498 if (current == GST_STATE_PAUSED)
2499 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2500 goto activate_failure;
2502 case GST_STATE_NULL:
2503 if (current == GST_STATE_READY)
2504 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2505 goto activate_failure;
2511 /* this flag is used to make the async state changes return immediately. We
2512 * don't want them to interfere with this state change */
2513 GST_OBJECT_LOCK (bin);
2514 bin->polling = TRUE;
2515 GST_OBJECT_UNLOCK (bin);
2517 /* iterate in state change order */
2518 it = gst_bin_iterate_sorted (bin);
2520 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2521 * Note how we don't reset this value when a resync happens, the reason being
2522 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2523 * even after a resync when the async element is gone */
2527 /* take base_time */
2528 base_time = gst_element_get_base_time (element);
2529 start_time = gst_element_get_start_time (element);
2531 have_no_preroll = FALSE;
2535 switch (gst_iterator_next (it, &data)) {
2536 case GST_ITERATOR_OK:
2540 child = g_value_get_object (&data);
2542 /* set state and base_time now */
2543 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2547 case GST_STATE_CHANGE_SUCCESS:
2548 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2549 "child '%s' changed state to %d(%s) successfully",
2550 GST_ELEMENT_NAME (child), next,
2551 gst_element_state_get_name (next));
2553 case GST_STATE_CHANGE_ASYNC:
2555 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2556 "child '%s' is changing state asynchronously to %s",
2557 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2561 case GST_STATE_CHANGE_FAILURE:{
2564 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2565 "child '%s' failed to go to state %d(%s)",
2566 GST_ELEMENT_NAME (child),
2567 next, gst_element_state_get_name (next));
2569 /* Only fail if the child is still inside
2570 * this bin. It might've been removed already
2571 * because of the error by the bin subclass
2572 * to ignore the error. */
2573 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2574 if (parent == GST_OBJECT_CAST (element)) {
2575 /* element is still in bin, really error now */
2576 gst_object_unref (parent);
2579 /* child removed from bin, let the resync code redo the state
2581 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2582 "child '%s' was removed from the bin",
2583 GST_ELEMENT_NAME (child));
2586 gst_object_unref (parent);
2590 case GST_STATE_CHANGE_NO_PREROLL:
2591 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2592 "child '%s' changed state to %d(%s) successfully without preroll",
2593 GST_ELEMENT_NAME (child), next,
2594 gst_element_state_get_name (next));
2595 have_no_preroll = TRUE;
2598 g_assert_not_reached ();
2601 g_value_reset (&data);
2604 case GST_ITERATOR_RESYNC:
2605 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2606 gst_iterator_resync (it);
2609 case GST_ITERATOR_DONE:
2610 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2616 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
2617 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2620 if (have_no_preroll) {
2621 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2622 "we have NO_PREROLL elements %s -> NO_PREROLL",
2623 gst_element_state_change_return_get_name (ret));
2624 ret = GST_STATE_CHANGE_NO_PREROLL;
2625 } else if (have_async) {
2626 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2627 "we have ASYNC elements %s -> ASYNC",
2628 gst_element_state_change_return_get_name (ret));
2629 ret = GST_STATE_CHANGE_ASYNC;
2633 g_value_unset (&data);
2634 gst_iterator_free (it);
2636 GST_OBJECT_LOCK (bin);
2637 bin->polling = FALSE;
2638 /* it's possible that we did not get ASYNC from the children while the bin is
2639 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2640 * itself as the source. In that case we still want to check if the state
2641 * change completed. */
2642 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2643 /* no element returned ASYNC and there are no pending async_done messages,
2644 * we can just complete. */
2645 GST_DEBUG_OBJECT (bin, "no async elements");
2648 /* when we get here an ASYNC element was found */
2649 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2650 /* we ignore ASYNC state changes when we go to READY or NULL */
2651 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2652 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2656 GST_DEBUG_OBJECT (bin, "check async elements");
2657 /* check if all elements managed to commit their state already */
2658 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2659 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2660 * all the elements commited their state while we were doing the state
2661 * change. We will still return ASYNC for consistency but we commit the
2662 * state already so that a _get_state() will return immediately. */
2663 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2665 GST_DEBUG_OBJECT (bin, "async elements commited");
2666 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE, FALSE);
2670 bin->priv->pending_async_done = FALSE;
2671 GST_OBJECT_UNLOCK (bin);
2673 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2674 "done changing bin's state from %s to %s, now in %s, ret %s",
2675 gst_element_state_get_name (current),
2676 gst_element_state_get_name (next),
2677 gst_element_state_get_name (GST_STATE (element)),
2678 gst_element_state_change_return_get_name (ret));
2685 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2686 "failure (de)activating src pads");
2687 return GST_STATE_CHANGE_FAILURE;
2692 * This function is a utility event handler for seek events.
2693 * It will send the event to all sinks or sources depending on the
2696 * Applications are free to override this behaviour and
2697 * implement their own seek handler, but this will work for
2698 * pretty much all cases in practice.
2701 gst_bin_send_event (GstElement * element, GstEvent * event)
2703 GstBin *bin = GST_BIN_CAST (element);
2705 gboolean res = TRUE;
2706 gboolean done = FALSE;
2707 GValue data = { 0, };
2709 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2710 iter = gst_bin_iterate_sources (bin);
2711 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2712 GST_EVENT_TYPE_NAME (event));
2714 iter = gst_bin_iterate_sinks (bin);
2715 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2716 GST_EVENT_TYPE_NAME (event));
2720 switch (gst_iterator_next (iter, &data)) {
2721 case GST_ITERATOR_OK:
2723 GstElement *child = g_value_get_object (&data);;
2725 gst_event_ref (event);
2726 res &= gst_element_send_event (child, event);
2727 GST_LOG_OBJECT (child, "After handling %s event: %d",
2728 GST_EVENT_TYPE_NAME (event), res);
2731 case GST_ITERATOR_RESYNC:
2732 gst_iterator_resync (iter);
2735 case GST_ITERATOR_DONE:
2738 case GST_ITERATOR_ERROR:
2739 g_assert_not_reached ();
2743 g_value_unset (&data);
2744 gst_iterator_free (iter);
2745 gst_event_unref (event);
2750 /* this is the function called by the threadpool. When async elements commit
2751 * their state, this function will attempt to bring the bin to the next state.
2754 gst_bin_continue_func (BinContinueData * data)
2757 GstState current, next, pending;
2758 GstStateChange transition;
2761 pending = data->pending;
2763 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2764 GST_STATE_LOCK (bin);
2766 GST_DEBUG_OBJECT (bin, "doing state continue");
2767 GST_OBJECT_LOCK (bin);
2769 /* if a new state change happened after this thread was scheduled, we return
2771 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2774 current = GST_STATE (bin);
2775 next = GST_STATE_GET_NEXT (current, pending);
2776 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2778 GST_STATE_NEXT (bin) = next;
2779 GST_STATE_PENDING (bin) = pending;
2781 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2782 GST_OBJECT_UNLOCK (bin);
2784 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2785 "continue state change %s to %s, final %s",
2786 gst_element_state_get_name (current),
2787 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2789 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2791 GST_STATE_UNLOCK (bin);
2792 GST_DEBUG_OBJECT (bin, "state continue done");
2794 gst_object_unref (bin);
2795 g_slice_free (BinContinueData, data);
2800 GST_OBJECT_UNLOCK (bin);
2801 GST_STATE_UNLOCK (bin);
2802 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2803 gst_object_unref (bin);
2804 g_slice_free (BinContinueData, data);
2809 static GstBusSyncReply
2810 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2812 GstBinClass *bclass;
2814 bclass = GST_BIN_GET_CLASS (bin);
2815 if (bclass->handle_message)
2816 bclass->handle_message (bin, message);
2818 gst_message_unref (message);
2820 return GST_BUS_DROP;
2824 bin_push_state_continue (BinContinueData * data)
2831 klass = GST_BIN_GET_CLASS (bin);
2833 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2834 g_thread_pool_push (klass->pool, data, NULL);
2837 /* an element started an async state change, if we were not busy with a state
2838 * change, we perform a lost state.
2839 * This function is called with the OBJECT lock.
2842 bin_handle_async_start (GstBin * bin)
2844 GstState old_state, new_state;
2846 GstMessage *amessage = NULL;
2848 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2851 /* get our toplevel state */
2852 toplevel = BIN_IS_TOPLEVEL (bin);
2854 /* prepare an ASYNC_START message, we always post the start message even if we
2855 * are busy with a state change or when we are NO_PREROLL. */
2857 /* non toplevel bin, prepare async-start for the parent */
2858 amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
2860 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2863 /* async starts are ignored when we are NO_PREROLL */
2864 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2865 goto was_no_preroll;
2867 old_state = GST_STATE (bin);
2869 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2870 * PLAYING after optionally redistributing the base_time. */
2871 if (old_state > GST_STATE_PAUSED)
2872 new_state = GST_STATE_PAUSED;
2874 new_state = old_state;
2876 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2877 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2878 gst_element_state_get_name (new_state));
2880 GST_STATE (bin) = new_state;
2881 GST_STATE_NEXT (bin) = new_state;
2882 GST_STATE_PENDING (bin) = new_state;
2883 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2884 GST_OBJECT_UNLOCK (bin);
2887 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2892 /* post our ASYNC_START. */
2893 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2894 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2896 GST_OBJECT_LOCK (bin);
2902 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2907 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2908 GST_OBJECT_UNLOCK (bin);
2913 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2914 GST_OBJECT_UNLOCK (bin);
2919 /* this function is called when there are no more async elements in the bin. We
2920 * post a state changed message and an ASYNC_DONE message.
2921 * This function is called with the OBJECT lock.
2924 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2925 gboolean flag_pending, gboolean reset_time)
2927 GstState current, pending, target;
2928 GstStateChangeReturn old_ret;
2929 GstState old_state, old_next;
2930 gboolean toplevel, state_changed = FALSE;
2931 GstMessage *amessage = NULL;
2932 BinContinueData *cont = NULL;
2934 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2937 pending = GST_STATE_PENDING (bin);
2942 /* check if there is something to commit */
2943 if (pending == GST_STATE_VOID_PENDING)
2944 goto nothing_pending;
2946 old_ret = GST_STATE_RETURN (bin);
2947 GST_STATE_RETURN (bin) = ret;
2949 /* move to the next target state */
2950 target = GST_STATE_TARGET (bin);
2951 pending = GST_STATE_PENDING (bin) = target;
2953 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), reset_time);
2955 old_state = GST_STATE (bin);
2956 /* this is the state we should go to next */
2957 old_next = GST_STATE_NEXT (bin);
2959 if (old_next != GST_STATE_PLAYING) {
2960 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2961 "committing state from %s to %s, old pending %s",
2962 gst_element_state_get_name (old_state),
2963 gst_element_state_get_name (old_next),
2964 gst_element_state_get_name (pending));
2966 /* update current state */
2967 current = GST_STATE (bin) = old_next;
2969 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2970 "setting state from %s to %s, pending %s",
2971 gst_element_state_get_name (old_state),
2972 gst_element_state_get_name (old_state),
2973 gst_element_state_get_name (pending));
2974 current = old_state;
2977 /* get our toplevel state */
2978 toplevel = BIN_IS_TOPLEVEL (bin);
2980 /* see if we reached the final state. If we are not toplevel, we also have to
2981 * stop here, the parent will continue our state. */
2982 if ((pending == current) || !toplevel) {
2983 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2984 "completed state change, pending VOID");
2986 /* mark VOID pending */
2987 pending = GST_STATE_VOID_PENDING;
2988 GST_STATE_PENDING (bin) = pending;
2989 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2991 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2992 "continue state change, pending %s",
2993 gst_element_state_get_name (pending));
2995 cont = g_slice_new (BinContinueData);
2997 /* ref to the bin */
2998 cont->bin = gst_object_ref (bin);
2999 /* cookie to detect concurrent state change */
3000 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
3001 /* pending target state */
3002 cont->pending = pending;
3004 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
3005 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
3008 if (old_next != GST_STATE_PLAYING) {
3009 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
3010 state_changed = TRUE;
3013 GST_OBJECT_UNLOCK (bin);
3015 if (state_changed) {
3016 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
3020 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
3021 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3022 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3025 GST_OBJECT_LOCK (bin);
3027 /* toplevel, start continue state */
3028 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3029 bin_push_state_continue (cont);
3031 GST_DEBUG_OBJECT (bin, "state change complete");
3032 GST_STATE_BROADCAST (bin);
3038 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3043 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3044 /* if we were busy with a state change and we are requested to flag a
3045 * pending async done, we do so here */
3047 bin->priv->pending_async_done = TRUE;
3052 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3058 bin_do_eos (GstBin * bin)
3063 GST_OBJECT_LOCK (bin);
3064 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3065 * we forward the EOS message to the parent bin or application
3067 eos = GST_STATE (bin) == GST_STATE_PLAYING
3068 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3069 && is_eos (bin, &seqnum);
3070 GST_OBJECT_UNLOCK (bin);
3073 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3075 GstMessage *tmessage;
3076 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3077 gst_message_set_seqnum (tmessage, seqnum);
3078 GST_DEBUG_OBJECT (bin,
3079 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3080 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3084 /* must be called with the object lock. This function releases the lock to post
3087 bin_do_message_forward (GstBin * bin, GstMessage * message)
3089 if (bin->priv->message_forward) {
3090 GstMessage *forwarded;
3092 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3093 GST_MESSAGE_TYPE_NAME (message));
3094 GST_OBJECT_UNLOCK (bin);
3096 /* we need to convert these messages to element messages so that our parent
3097 * bin can easily ignore them and so that the application can easily
3098 * distinguish between the internally forwarded and the real messages. */
3099 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3100 gst_structure_new ("GstBinForwarded",
3101 "message", GST_TYPE_MESSAGE, message, NULL));
3103 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3105 GST_OBJECT_LOCK (bin);
3109 /* handle child messages:
3111 * This method is called synchronously when a child posts a message on
3114 * GST_MESSAGE_EOS: This message is only posted by sinks
3115 * in the PLAYING state. If all sinks posted the EOS message, post
3118 * GST_MESSAGE_STATE_DIRTY: Deprecated
3120 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3121 * element posts segment_start twice, only the last message is kept.
3123 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3124 * with the segment_done message. If there are no more segment_start
3125 * messages, post segment_done message upwards.
3127 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3128 * Whenever someone performs a duration query on the bin, we store the
3129 * result so we can answer it quicker the next time. Any element that
3130 * changes its duration marks our cached values invalid.
3131 * This message is also posted upwards. This is currently disabled
3132 * because too many elements don't post DURATION messages when the
3135 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3136 * can no longer provide a clock. The default bin behaviour is to
3137 * check if the lost clock was the one provided by the bin. If so and
3138 * we are currently in the PLAYING state, we forward the message to
3140 * This message is also generated when we remove a clock provider from
3141 * a bin. If this message is received by the application, it should
3142 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3143 * and a new base_time distribution.
3145 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3146 * can provide a clock. This mostly happens when we add a new clock
3147 * provider to the bin. The default behaviour of the bin is to mark the
3148 * currently selected clock as dirty, which will perform a clock
3149 * recalculation the next time we are asked to provide a clock.
3150 * This message is never sent to the application but is forwarded to
3153 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3154 * the state of the element and the fact that the element will need a
3155 * new base_time. This message is not forwarded to the application.
3157 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3158 * element when it posted ASYNC_START. If all elements are done, post a
3159 * ASYNC_DONE message to the parent.
3161 * OTHER: post upwards.
3164 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3167 GstMessageType type;
3168 GstMessage *tmessage;
3171 src = GST_MESSAGE_SRC (message);
3172 type = GST_MESSAGE_TYPE (message);
3174 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3175 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3176 GST_MESSAGE_TYPE_NAME (message));
3179 case GST_MESSAGE_ERROR:
3181 GST_OBJECT_LOCK (bin);
3183 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3184 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3185 GST_STATE_BROADCAST (bin);
3186 GST_OBJECT_UNLOCK (bin);
3190 case GST_MESSAGE_EOS:
3193 /* collect all eos messages from the children */
3194 GST_OBJECT_LOCK (bin);
3195 bin_do_message_forward (bin, message);
3196 /* ref message for future use */
3197 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3198 GST_OBJECT_UNLOCK (bin);
3203 case GST_MESSAGE_STATE_DIRTY:
3205 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3208 gst_message_unref (message);
3211 case GST_MESSAGE_SEGMENT_START:{
3212 gboolean post = FALSE;
3216 gst_message_parse_segment_start (message, &format, &position);
3217 seqnum = gst_message_get_seqnum (message);
3219 GST_OBJECT_LOCK (bin);
3220 bin_do_message_forward (bin, message);
3221 /* if this is the first segment-start, post to parent but not to the
3223 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3224 (GST_OBJECT_PARENT (bin) != NULL)) {
3227 /* replace any previous segment_start message from this source
3228 * with the new segment start message */
3229 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3230 GST_OBJECT_UNLOCK (bin);
3232 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3234 gst_message_set_seqnum (tmessage, seqnum);
3236 /* post segment start with initial format and position. */
3237 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3239 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3243 case GST_MESSAGE_SEGMENT_DONE:
3245 gboolean post = FALSE;
3249 gst_message_parse_segment_done (message, &format, &position);
3250 seqnum = gst_message_get_seqnum (message);
3252 GST_OBJECT_LOCK (bin);
3253 bin_do_message_forward (bin, message);
3254 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3255 /* if there are no more segment_start messages, everybody posted
3256 * a segment_done and we can post one on the bus. */
3258 /* we don't care who still has a pending segment start */
3259 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3262 /* remove all old segment_done messages */
3263 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3265 GST_OBJECT_UNLOCK (bin);
3267 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3269 gst_message_set_seqnum (tmessage, seqnum);
3271 /* post segment done with latest format and position. */
3272 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3274 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3278 case GST_MESSAGE_DURATION:
3280 /* remove all cached duration messages, next time somebody asks
3281 * for duration, we will recalculate. */
3282 GST_OBJECT_LOCK (bin);
3283 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3284 GST_OBJECT_UNLOCK (bin);
3287 case GST_MESSAGE_CLOCK_LOST:
3289 GstClock **provided_clock_p;
3290 GstElement **clock_provider_p;
3291 gboolean playing, provided, forward;
3294 gst_message_parse_clock_lost (message, &clock);
3296 GST_OBJECT_LOCK (bin);
3297 bin->clock_dirty = TRUE;
3298 /* if we lost the clock that we provided, post to parent but
3299 * only if we are PLAYING. */
3300 provided = (clock == bin->provided_clock);
3301 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3302 forward = playing & provided;
3304 GST_DEBUG_OBJECT (bin,
3305 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3306 bin->provided_clock, bin->clock_provider);
3307 provided_clock_p = &bin->provided_clock;
3308 clock_provider_p = &bin->clock_provider;
3309 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3310 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3312 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3313 provided, playing, forward);
3314 GST_OBJECT_UNLOCK (bin);
3320 gst_message_unref (message);
3323 case GST_MESSAGE_CLOCK_PROVIDE:
3327 GST_OBJECT_LOCK (bin);
3328 bin->clock_dirty = TRUE;
3329 /* a new clock is available, post to parent but not
3330 * to the application */
3331 forward = GST_OBJECT_PARENT (bin) != NULL;
3332 GST_OBJECT_UNLOCK (bin);
3338 gst_message_unref (message);
3341 case GST_MESSAGE_ASYNC_START:
3345 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3346 src ? GST_OBJECT_NAME (src) : "(NULL)");
3348 GST_OBJECT_LOCK (bin);
3349 bin_do_message_forward (bin, message);
3351 /* we ignore the message if we are going to <= READY */
3352 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3353 goto ignore_start_message;
3355 /* takes ownership of the message */
3356 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3358 bin_handle_async_start (bin);
3359 GST_OBJECT_UNLOCK (bin);
3362 ignore_start_message:
3364 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3365 gst_element_state_get_name (target));
3366 GST_OBJECT_UNLOCK (bin);
3367 gst_message_unref (message);
3371 case GST_MESSAGE_ASYNC_DONE:
3373 gboolean reset_time;
3376 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3377 src ? GST_OBJECT_NAME (src) : "(NULL)");
3379 gst_message_parse_async_done (message, &reset_time);
3381 GST_OBJECT_LOCK (bin);
3382 bin_do_message_forward (bin, message);
3384 /* ignore messages if we are shutting down */
3385 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3386 goto ignore_done_message;
3388 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3389 /* if there are no more ASYNC_START messages, everybody posted
3390 * a ASYNC_DONE and we can post one on the bus. When checking, we
3391 * don't care who still has a pending ASYNC_START */
3392 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3393 /* nothing found, remove all old ASYNC_DONE messages */
3394 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3396 GST_DEBUG_OBJECT (bin, "async elements commited");
3397 /* when we get an async done message when a state change was busy, we
3398 * need to set the pending_done flag so that at the end of the state
3399 * change we can see if we need to verify pending async elements, hence
3400 * the TRUE argument here. */
3401 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE, reset_time);
3403 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3405 GST_OBJECT_UNLOCK (bin);
3408 ignore_done_message:
3410 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3411 gst_element_state_get_name (target));
3412 GST_OBJECT_UNLOCK (bin);
3413 gst_message_unref (message);
3417 case GST_MESSAGE_STRUCTURE_CHANGE:
3421 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3423 GST_OBJECT_LOCK (bin);
3425 /* while the pad is busy, avoid following it when doing state changes.
3426 * Don't update the cookie yet, we will do that after the structure
3427 * change finished and we are ready to inspect the new updated
3429 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3432 /* a pad link/unlink ended, signal the state change iterator that we
3433 * need to resync by updating the structure_cookie. */
3434 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3435 GST_MESSAGE_STRUCTURE_CHANGE);
3436 bin->priv->structure_cookie++;
3438 GST_OBJECT_UNLOCK (bin);
3441 gst_message_unref (message);
3452 /* Send all other messages upward */
3453 GST_DEBUG_OBJECT (bin, "posting message upward");
3454 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3459 /* generic struct passed to all query fold methods */
3468 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3469 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3471 /* for duration/position we collect all durations/positions and take
3472 * the MAX of all valid results */
3474 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3482 bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3484 GstElement *item = g_value_get_object (vitem);
3486 if (gst_element_query (item, fold->query)) {
3489 g_value_set_boolean (ret, TRUE);
3491 gst_query_parse_duration (fold->query, NULL, &duration);
3493 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3495 if (duration > fold->max)
3496 fold->max = duration;
3503 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3507 gst_query_parse_duration (fold->query, &format, NULL);
3508 /* store max in query result */
3509 gst_query_set_duration (fold->query, format, fold->max);
3511 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3514 GST_OBJECT_LOCK (bin);
3515 bin->messages = g_list_prepend (bin->messages,
3516 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3517 GST_OBJECT_UNLOCK (bin);
3521 bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3523 GstElement *item = g_value_get_object (vitem);
3525 if (gst_element_query (item, fold->query)) {
3528 g_value_set_boolean (ret, TRUE);
3530 gst_query_parse_position (fold->query, NULL, &position);
3532 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3534 if (position > fold->max)
3535 fold->max = position;
3542 bin_query_position_done (GstBin * bin, QueryFold * fold)
3546 gst_query_parse_position (fold->query, &format, NULL);
3547 /* store max in query result */
3548 gst_query_set_position (fold->query, format, fold->max);
3550 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3554 bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3556 GstElement *item = g_value_get_object (vitem);
3558 if (gst_element_query (item, fold->query)) {
3559 GstClockTime min, max;
3562 gst_query_parse_latency (fold->query, &live, &min, &max);
3564 GST_DEBUG_OBJECT (item,
3565 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3566 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3568 /* for the combined latency we collect the MAX of all min latencies and
3569 * the MIN of all max latencies */
3571 if (min > fold->min)
3573 if (fold->max == -1)
3575 else if (max < fold->max)
3577 if (fold->live == FALSE)
3581 g_value_set_boolean (ret, FALSE);
3582 GST_DEBUG_OBJECT (item, "failed query");
3589 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3591 /* store max in query result */
3592 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3594 GST_DEBUG_OBJECT (bin,
3595 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3596 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3600 /* generic fold, return first valid result */
3602 bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
3604 GstElement *item = g_value_get_object (vitem);
3607 if ((res = gst_element_query (item, fold->query))) {
3608 g_value_set_boolean (ret, TRUE);
3609 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3612 /* and stop as soon as we have a valid result */
3617 gst_bin_query (GstElement * element, GstQuery * query)
3619 GstBin *bin = GST_BIN_CAST (element);
3621 gboolean res = FALSE;
3622 GstIteratorFoldFunction fold_func;
3623 QueryInitFunction fold_init = NULL;
3624 QueryDoneFunction fold_done = NULL;
3625 QueryFold fold_data;
3628 switch (GST_QUERY_TYPE (query)) {
3629 case GST_QUERY_DURATION:
3634 gst_query_parse_duration (query, &qformat, NULL);
3636 /* find cached duration query */
3637 GST_OBJECT_LOCK (bin);
3638 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3639 GstMessage *message = (GstMessage *) cached->data;
3641 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3642 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3646 gst_message_parse_duration (message, &format, &duration);
3648 /* if cached same format, copy duration in query result */
3649 if (format == qformat) {
3650 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3652 GST_OBJECT_UNLOCK (bin);
3654 gst_query_set_duration (query, qformat, duration);
3660 GST_OBJECT_UNLOCK (bin);
3661 /* no cached value found, iterate and collect durations */
3662 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3663 fold_init = bin_query_min_max_init;
3664 fold_done = bin_query_duration_done;
3667 case GST_QUERY_POSITION:
3669 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3670 fold_init = bin_query_min_max_init;
3671 fold_done = bin_query_position_done;
3674 case GST_QUERY_LATENCY:
3676 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3677 fold_init = bin_query_min_max_init;
3678 fold_done = bin_query_latency_done;
3683 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3687 fold_data.query = query;
3689 /* set the result of the query to FALSE initially */
3690 g_value_init (&ret, G_TYPE_BOOLEAN);
3691 g_value_set_boolean (&ret, res);
3693 iter = gst_bin_iterate_sinks (bin);
3694 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3695 query, GST_QUERY_TYPE_NAME (query));
3698 fold_init (bin, &fold_data);
3701 GstIteratorResult ires;
3703 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3706 case GST_ITERATOR_RESYNC:
3707 gst_iterator_resync (iter);
3709 fold_init (bin, &fold_data);
3710 g_value_set_boolean (&ret, res);
3712 case GST_ITERATOR_OK:
3713 case GST_ITERATOR_DONE:
3714 res = g_value_get_boolean (&ret);
3715 if (fold_done != NULL && res)
3716 fold_done (bin, &fold_data);
3724 gst_iterator_free (iter);
3727 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3733 compare_name (const GValue * velement, const gchar * name)
3736 GstElement *element = g_value_get_object (velement);
3738 GST_OBJECT_LOCK (element);
3739 eq = strcmp (GST_ELEMENT_NAME (element), name);
3740 GST_OBJECT_UNLOCK (element);
3746 * gst_bin_get_by_name:
3748 * @name: the element name to search for
3750 * Gets the element with the given name from a bin. This
3751 * function recurses into child bins.
3753 * Returns NULL if no element with the given name is found in the bin.
3755 * MT safe. Caller owns returned reference.
3757 * Returns: (transfer full): the #GstElement with the given name, or NULL
3760 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3762 GstIterator *children;
3763 GValue result = { 0, };
3764 GstElement *element;
3767 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3769 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3770 GST_ELEMENT_NAME (bin), name);
3772 children = gst_bin_iterate_recurse (bin);
3773 found = gst_iterator_find_custom (children,
3774 (GCompareFunc) compare_name, &result, (gpointer) name);
3775 gst_iterator_free (children);
3778 element = g_value_dup_object (&result);
3779 g_value_unset (&result);
3788 * gst_bin_get_by_name_recurse_up:
3790 * @name: the element name to search for
3792 * Gets the element with the given name from this bin. If the
3793 * element is not found, a recursion is performed on the parent bin.
3796 * - no element with the given name is found in the bin
3798 * MT safe. Caller owns returned reference.
3800 * Returns: (transfer full): the #GstElement with the given name, or NULL
3803 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3807 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3808 g_return_val_if_fail (name != NULL, NULL);
3810 result = gst_bin_get_by_name (bin, name);
3815 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3817 if (GST_IS_BIN (parent)) {
3818 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3820 gst_object_unref (parent);
3828 compare_interface (const GValue * velement, GValue * interface)
3830 GstElement *element = g_value_get_object (velement);
3831 GType interface_type = (GType) g_value_get_pointer (interface);
3834 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3843 * gst_bin_get_by_interface:
3845 * @iface: the #GType of an interface
3847 * Looks for an element inside the bin that implements the given
3848 * interface. If such an element is found, it returns the element.
3849 * You can cast this element to the given interface afterwards. If you want
3850 * all elements that implement the interface, use
3851 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3853 * MT safe. Caller owns returned reference.
3855 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3858 gst_bin_get_by_interface (GstBin * bin, GType iface)
3860 GstIterator *children;
3861 GValue result = { 0, };
3862 GstElement *element;
3864 GValue viface = { 0, };
3866 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3867 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3869 g_value_init (&viface, G_TYPE_POINTER);
3870 g_value_set_pointer (&viface, (gpointer) iface);
3872 children = gst_bin_iterate_recurse (bin);
3873 found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3875 gst_iterator_free (children);
3878 element = g_value_dup_object (&result);
3879 g_value_unset (&result);
3883 g_value_unset (&viface);
3889 * gst_bin_iterate_all_by_interface:
3891 * @iface: the #GType of an interface
3893 * Looks for all elements inside the bin that implements the given
3894 * interface. You can safely cast all returned elements to the given interface.
3895 * The function recurses inside child bins. The iterator will yield a series
3896 * of #GstElement that should be unreffed after use.
3898 * Each element yielded by the iterator will have its refcount increased, so
3901 * MT safe. Caller owns returned value.
3903 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3904 * in the bin implementing the given interface, or NULL
3907 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3909 GstIterator *children;
3910 GstIterator *result;
3911 GValue viface = { 0, };
3913 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3914 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3916 g_value_init (&viface, G_TYPE_POINTER);
3917 g_value_set_pointer (&viface, (gpointer) iface);
3919 children = gst_bin_iterate_recurse (bin);
3920 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3923 g_value_unset (&viface);