2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2004,2005 Wim Taymans <wim@fluendo.com>
5 * gstpipeline.c: Overall pipeline management element
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
25 * @short_description: Top-level bin with clocking and bus management
27 * @see_also: #GstElement, #GstBin, #GstClock, #GstBus
29 * A #GstPipeline is a special #GstBin used as the toplevel container for
30 * the filter graph. The #GstPipeline will manage the selection and
31 * distribution of a global #GstClock as well as provide a #GstBus to the
34 * gst_pipeline_new() is used to create a pipeline. when you are done with
35 * the pipeline, use gst_object_unref() to free its resources including all
36 * added #GstElement objects (if not otherwise referenced).
38 * Elements are added and removed from the pipeline using the #GstBin
39 * methods like gst_bin_add() and gst_bin_remove() (see #GstBin).
41 * Before changing the state of the #GstPipeline (see #GstElement) a #GstBus
42 * can be retrieved with gst_pipeline_get_bus(). This bus can then be
43 * used to receive #GstMessage from the elements in the pipeline.
45 * By default, a #GstPipeline will automatically flush the pending #GstBus
46 * messages when going to the NULL state to ensure that no circular
47 * references exist when no messages are read from the #GstBus. This
48 * behaviour can be changed with gst_pipeline_set_auto_flush_bus().
50 * When the #GstPipeline performs the PAUSED to PLAYING state change it will
51 * select a clock for the elements. The clock selection algorithm will by
52 * default select a clock provided by an element that is most upstream
53 * (closest to the source). For live pipelines (ones that return
54 * #GST_STATE_CHANGE_NO_PREROLL from the gst_element_set_state() call) this
55 * will select the clock provided by the live source. For normal pipelines
56 * this will select a clock provided by the sinks (most likely the audio
57 * sink). If no element provides a clock, a default #GstSystemClock is used.
59 * The clock selection can be controlled with the gst_pipeline_use_clock()
60 * method, which will enforce a given clock on the pipeline. With
61 * gst_pipeline_auto_clock() the default clock selection algorithm can be
64 * A #GstPipeline maintains a running time for the elements. The running
65 * time is defined as the difference between the current clock time and
66 * the base time. When the pipeline goes to READY or a flushing seek is
67 * performed on it, the running time is reset to 0. When the pipeline is
68 * set from PLAYING to PAUSED, the current clock time is sampled and used to
69 * configure the base time for the elements when the pipeline is set
70 * to PLAYING again. The effect is that the running time (as the difference
71 * between the clock time and the base time) will count how much time was spent
72 * in the PLAYING state. This default behaviour can be changed with the
73 * gst_element_set_start_time() method.
76 #include "gst_private.h"
78 #include "gst-i18n-lib.h"
80 #include "gstpipeline.h"
82 #include "gstsystemclock.h"
85 GST_DEBUG_CATEGORY_STATIC (pipeline_debug);
86 #define GST_CAT_DEFAULT pipeline_debug
88 /* Pipeline signals and args */
95 #define DEFAULT_DELAY 0
96 #define DEFAULT_AUTO_FLUSH_BUS TRUE
105 #define GST_PIPELINE_GET_PRIVATE(obj) \
106 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_PIPELINE, GstPipelinePrivate))
108 struct _GstPipelinePrivate
111 gboolean auto_flush_bus;
113 /* when we need to update stream_time or clock when going back to
115 GstClockTime last_start_time;
116 gboolean update_clock;
120 static void gst_pipeline_dispose (GObject * object);
121 static void gst_pipeline_set_property (GObject * object, guint prop_id,
122 const GValue * value, GParamSpec * pspec);
123 static void gst_pipeline_get_property (GObject * object, guint prop_id,
124 GValue * value, GParamSpec * pspec);
126 static GstClock *gst_pipeline_provide_clock_func (GstElement * element);
127 static GstStateChangeReturn gst_pipeline_change_state (GstElement * element,
128 GstStateChange transition);
130 static void gst_pipeline_handle_message (GstBin * bin, GstMessage * message);
132 /* static guint gst_pipeline_signals[LAST_SIGNAL] = { 0 }; */
136 GST_DEBUG_CATEGORY_INIT (pipeline_debug, "pipeline", GST_DEBUG_BOLD, \
137 "debugging info for the 'pipeline' container element"); \
140 #define gst_pipeline_parent_class parent_class
141 G_DEFINE_TYPE_WITH_CODE (GstPipeline, gst_pipeline, GST_TYPE_BIN, _do_init);
144 gst_pipeline_class_init (GstPipelineClass * klass)
146 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
147 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
148 GstBinClass *gstbin_class = GST_BIN_CLASS (klass);
150 g_type_class_add_private (klass, sizeof (GstPipelinePrivate));
152 gobject_class->set_property = gst_pipeline_set_property;
153 gobject_class->get_property = gst_pipeline_get_property;
158 * The expected delay needed for elements to spin up to the
159 * PLAYING state expressed in nanoseconds.
160 * see gst_pipeline_set_delay() for more information on this option.
162 g_object_class_install_property (gobject_class, PROP_DELAY,
163 g_param_spec_uint64 ("delay", "Delay",
164 "Expected delay needed for elements "
165 "to spin up to PLAYING in nanoseconds", 0, G_MAXUINT64, DEFAULT_DELAY,
166 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
169 * GstPipeline:auto-flush-bus:
171 * Whether or not to automatically flush all messages on the
172 * pipeline's bus when going from READY to NULL state. Please see
173 * gst_pipeline_set_auto_flush_bus() for more information on this option.
175 g_object_class_install_property (gobject_class, PROP_AUTO_FLUSH_BUS,
176 g_param_spec_boolean ("auto-flush-bus", "Auto Flush Bus",
177 "Whether to automatically flush the pipeline's bus when going "
178 "from READY into NULL state", DEFAULT_AUTO_FLUSH_BUS,
179 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
181 gobject_class->dispose = gst_pipeline_dispose;
183 gst_element_class_set_static_metadata (gstelement_class, "Pipeline object",
185 "Complete pipeline object",
186 "Erik Walthinsen <omega@cse.ogi.edu>, Wim Taymans <wim@fluendo.com>");
188 gstelement_class->change_state =
189 GST_DEBUG_FUNCPTR (gst_pipeline_change_state);
190 gstelement_class->provide_clock =
191 GST_DEBUG_FUNCPTR (gst_pipeline_provide_clock_func);
192 gstbin_class->handle_message =
193 GST_DEBUG_FUNCPTR (gst_pipeline_handle_message);
197 gst_pipeline_init (GstPipeline * pipeline)
201 pipeline->priv = GST_PIPELINE_GET_PRIVATE (pipeline);
203 /* set default property values */
204 pipeline->priv->auto_flush_bus = DEFAULT_AUTO_FLUSH_BUS;
205 pipeline->delay = DEFAULT_DELAY;
207 /* create and set a default bus */
208 bus = gst_bus_new ();
210 /* FIXME, disabled for 0.10.5 release as it caused to many regressions */
211 /* Start our bus in flushing if appropriate */
212 if (pipeline->priv->auto_flush_bus)
213 gst_bus_set_flushing (bus, TRUE);
216 gst_element_set_bus (GST_ELEMENT_CAST (pipeline), bus);
217 GST_DEBUG_OBJECT (pipeline, "set bus %" GST_PTR_FORMAT " on pipeline", bus);
218 gst_object_unref (bus);
222 gst_pipeline_dispose (GObject * object)
224 GstPipeline *pipeline = GST_PIPELINE (object);
225 GstClock **clock_p = &pipeline->fixed_clock;
227 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, pipeline, "dispose");
229 /* clear and unref any fixed clock */
230 gst_object_replace ((GstObject **) clock_p, NULL);
232 G_OBJECT_CLASS (parent_class)->dispose (object);
236 gst_pipeline_set_property (GObject * object, guint prop_id,
237 const GValue * value, GParamSpec * pspec)
239 GstPipeline *pipeline = GST_PIPELINE (object);
243 gst_pipeline_set_delay (pipeline, g_value_get_uint64 (value));
245 case PROP_AUTO_FLUSH_BUS:
246 gst_pipeline_set_auto_flush_bus (pipeline, g_value_get_boolean (value));
249 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
255 gst_pipeline_get_property (GObject * object, guint prop_id,
256 GValue * value, GParamSpec * pspec)
258 GstPipeline *pipeline = GST_PIPELINE (object);
262 g_value_set_uint64 (value, gst_pipeline_get_delay (pipeline));
264 case PROP_AUTO_FLUSH_BUS:
265 g_value_set_boolean (value, gst_pipeline_get_auto_flush_bus (pipeline));
268 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
273 /* set the start_time to 0, this will cause us to select a new base_time and
274 * make the running_time start from 0 again. */
276 reset_start_time (GstPipeline * pipeline, GstClockTime start_time)
278 GST_OBJECT_LOCK (pipeline);
279 if (GST_ELEMENT_START_TIME (pipeline) != GST_CLOCK_TIME_NONE) {
280 GST_DEBUG_OBJECT (pipeline, "reset start_time to 0");
281 GST_ELEMENT_START_TIME (pipeline) = start_time;
282 pipeline->priv->last_start_time = -1;
284 GST_DEBUG_OBJECT (pipeline, "application asked to not reset stream_time");
286 GST_OBJECT_UNLOCK (pipeline);
291 * @name: (allow-none): name of new pipeline
293 * Create a new pipeline with the given name.
295 * Returns: (transfer floating): newly created GstPipeline
300 gst_pipeline_new (const gchar * name)
302 return gst_element_factory_make ("pipeline", name);
305 /* takes a snapshot of the running_time of the pipeline and store this as the
306 * element start_time. This is the time we will set as the running_time of the
307 * pipeline when we go to PLAYING next. */
309 pipeline_update_start_time (GstElement * element)
311 GstPipeline *pipeline = GST_PIPELINE_CAST (element);
314 GST_OBJECT_LOCK (element);
315 if ((clock = element->clock)) {
318 gst_object_ref (clock);
319 GST_OBJECT_UNLOCK (element);
321 /* calculate the time when we stopped */
322 now = gst_clock_get_time (clock);
323 gst_object_unref (clock);
325 GST_OBJECT_LOCK (element);
326 /* store the current running time */
327 if (GST_ELEMENT_START_TIME (pipeline) != GST_CLOCK_TIME_NONE) {
328 if (now != GST_CLOCK_TIME_NONE)
329 GST_ELEMENT_START_TIME (pipeline) = now - element->base_time;
331 GST_WARNING_OBJECT (element,
332 "Clock %s returned invalid time, can't calculate "
333 "running_time when going to the PAUSED state",
334 GST_OBJECT_NAME (clock));
336 /* we went to PAUSED, when going to PLAYING select clock and new
338 pipeline->priv->update_clock = TRUE;
340 GST_DEBUG_OBJECT (element,
341 "start_time=%" GST_TIME_FORMAT ", now=%" GST_TIME_FORMAT
342 ", base_time %" GST_TIME_FORMAT,
343 GST_TIME_ARGS (GST_ELEMENT_START_TIME (pipeline)),
344 GST_TIME_ARGS (now), GST_TIME_ARGS (element->base_time));
346 GST_OBJECT_UNLOCK (element);
350 static GstStateChangeReturn
351 gst_pipeline_change_state (GstElement * element, GstStateChange transition)
353 GstStateChangeReturn result = GST_STATE_CHANGE_SUCCESS;
354 GstPipeline *pipeline = GST_PIPELINE_CAST (element);
357 switch (transition) {
358 case GST_STATE_CHANGE_NULL_TO_READY:
359 GST_OBJECT_LOCK (element);
361 gst_bus_set_flushing (element->bus, FALSE);
362 GST_OBJECT_UNLOCK (element);
364 case GST_STATE_CHANGE_READY_TO_PAUSED:
365 GST_OBJECT_LOCK (element);
366 pipeline->priv->update_clock = TRUE;
367 GST_OBJECT_UNLOCK (element);
369 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
371 GstClockTime now, start_time, last_start_time, delay;
372 gboolean update_clock;
375 GST_DEBUG_OBJECT (element, "selecting clock and base_time");
377 GST_OBJECT_LOCK (element);
378 cur_clock = element->clock;
380 gst_object_ref (cur_clock);
381 /* get the desired running_time of the first buffer aka the start_time */
382 start_time = GST_ELEMENT_START_TIME (pipeline);
383 last_start_time = pipeline->priv->last_start_time;
384 pipeline->priv->last_start_time = start_time;
385 /* see if we need to update the clock */
386 update_clock = pipeline->priv->update_clock;
387 pipeline->priv->update_clock = FALSE;
388 delay = pipeline->delay;
389 GST_OBJECT_UNLOCK (element);
391 /* running time changed, either with a PAUSED or a flush, we need to check
392 * if there is a new clock & update the base time */
393 /* only do this for top-level, however */
394 if (GST_OBJECT_PARENT (element) == NULL &&
395 (update_clock || last_start_time != start_time)) {
396 GST_DEBUG_OBJECT (pipeline, "Need to update start_time");
398 /* when going to PLAYING, select a clock when needed. If we just got
399 * flushed, we don't reselect the clock. */
401 GST_DEBUG_OBJECT (pipeline, "Need to update clock.");
402 clock = gst_element_provide_clock (element);
404 GST_DEBUG_OBJECT (pipeline,
405 "Don't need to update clock, using old clock.");
406 /* only try to ref if cur_clock is not NULL */
408 gst_object_ref (cur_clock);
413 now = gst_clock_get_time (clock);
415 GST_DEBUG_OBJECT (pipeline, "no clock, using base time of NONE");
416 now = GST_CLOCK_TIME_NONE;
419 if (clock != cur_clock) {
420 /* now distribute the clock (which could be NULL). If some
421 * element refuses the clock, this will return FALSE and
422 * we effectively fail the state change. */
423 if (!gst_element_set_clock (element, clock))
426 /* if we selected and distributed a new clock, let the app
428 gst_element_post_message (element,
429 gst_message_new_new_clock (GST_OBJECT_CAST (element), clock));
433 gst_object_unref (clock);
435 if (start_time != GST_CLOCK_TIME_NONE && now != GST_CLOCK_TIME_NONE) {
436 GstClockTime new_base_time = now - start_time + delay;
437 GST_DEBUG_OBJECT (element,
438 "start_time=%" GST_TIME_FORMAT ", now=%" GST_TIME_FORMAT
439 ", base_time %" GST_TIME_FORMAT,
440 GST_TIME_ARGS (start_time), GST_TIME_ARGS (now),
441 GST_TIME_ARGS (new_base_time));
443 gst_element_set_base_time (element, new_base_time);
445 GST_DEBUG_OBJECT (pipeline,
446 "NOT adjusting base_time because start_time is NONE");
449 GST_DEBUG_OBJECT (pipeline,
450 "NOT adjusting base_time because we selected one before");
454 gst_object_unref (cur_clock);
457 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
459 /* we take a start_time snapshot before calling the children state changes
460 * so that they know about when the pipeline PAUSED. */
461 pipeline_update_start_time (element);
464 case GST_STATE_CHANGE_PAUSED_TO_READY:
465 case GST_STATE_CHANGE_READY_TO_NULL:
469 result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
471 switch (transition) {
472 case GST_STATE_CHANGE_NULL_TO_READY:
474 case GST_STATE_CHANGE_READY_TO_PAUSED:
476 /* READY to PAUSED starts running_time from 0 */
477 reset_start_time (pipeline, 0);
480 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
482 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
484 /* Take a new snapshot of the start_time after calling the state change on
485 * all children. This will be the running_time of the pipeline when we go
487 pipeline_update_start_time (element);
490 case GST_STATE_CHANGE_PAUSED_TO_READY:
492 case GST_STATE_CHANGE_READY_TO_NULL:
497 /* grab some stuff before we release the lock to flush out the bus */
498 GST_OBJECT_LOCK (element);
499 if ((bus = element->bus))
500 gst_object_ref (bus);
501 auto_flush = pipeline->priv->auto_flush_bus;
502 GST_OBJECT_UNLOCK (element);
506 gst_bus_set_flushing (bus, TRUE);
508 GST_INFO_OBJECT (element, "not flushing bus, auto-flushing disabled");
510 gst_object_unref (bus);
520 /* we generate this error when the selected clock was not
521 * accepted by some element */
522 GST_ELEMENT_ERROR (pipeline, CORE, CLOCK,
523 (_("Selected clock cannot be used in pipeline.")),
524 ("Pipeline cannot operate with selected clock"));
525 GST_DEBUG_OBJECT (pipeline,
526 "Pipeline cannot operate with selected clock %p", clock);
528 gst_object_unref (clock);
529 return GST_STATE_CHANGE_FAILURE;
533 /* intercept the bus messages from our children. We watch for the ASYNC_START
534 * message with is posted by the elements (sinks) that require a reset of the
535 * running_time after a flush. ASYNC_START also brings the pipeline back into
536 * the PAUSED, pending PAUSED state. When the ASYNC_DONE message is received the
537 * pipeline will redistribute the new base_time and will bring the elements back
538 * to the desired state of the pipeline. */
540 gst_pipeline_handle_message (GstBin * bin, GstMessage * message)
542 GstPipeline *pipeline = GST_PIPELINE_CAST (bin);
544 switch (GST_MESSAGE_TYPE (message)) {
545 case GST_MESSAGE_RESET_TIME:
547 GstClockTime running_time;
549 gst_message_parse_reset_time (message, &running_time);
551 /* reset our running time if we need to distribute a new base_time to the
553 reset_start_time (pipeline, running_time);
556 case GST_MESSAGE_CLOCK_LOST:
560 gst_message_parse_clock_lost (message, &clock);
562 GST_OBJECT_LOCK (bin);
563 if (clock == GST_ELEMENT_CAST (bin)->clock) {
564 GST_DEBUG_OBJECT (bin, "Used clock '%s' got lost",
565 GST_OBJECT_NAME (clock));
566 pipeline->priv->update_clock = TRUE;
568 GST_OBJECT_UNLOCK (bin);
573 GST_BIN_CLASS (parent_class)->handle_message (bin, message);
577 * gst_pipeline_get_bus:
578 * @pipeline: a #GstPipeline
580 * Gets the #GstBus of @pipeline. The bus allows applications to receive
581 * #GstMessage packets.
583 * Returns: (transfer full): a #GstBus, unref after usage.
588 gst_pipeline_get_bus (GstPipeline * pipeline)
590 return gst_element_get_bus (GST_ELEMENT_CAST (pipeline));
594 gst_pipeline_provide_clock_func (GstElement * element)
596 GstClock *clock = NULL;
597 GstPipeline *pipeline = GST_PIPELINE (element);
599 /* if we have a fixed clock, use that one */
600 GST_OBJECT_LOCK (pipeline);
601 if (GST_OBJECT_FLAG_IS_SET (pipeline, GST_PIPELINE_FLAG_FIXED_CLOCK)) {
602 clock = pipeline->fixed_clock;
604 gst_object_ref (clock);
605 GST_OBJECT_UNLOCK (pipeline);
607 GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline using fixed clock %p (%s)",
608 clock, clock ? GST_STR_NULL (GST_OBJECT_NAME (clock)) : "-");
610 GST_OBJECT_UNLOCK (pipeline);
611 /* let the parent bin select a clock */
613 GST_ELEMENT_CLASS (parent_class)->provide_clock (GST_ELEMENT
615 /* no clock, use a system clock */
617 clock = gst_system_clock_obtain ();
619 GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline obtained system clock: %p (%s)",
620 clock, clock ? GST_STR_NULL (GST_OBJECT_NAME (clock)) : "-");
622 GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline obtained clock: %p (%s)",
623 clock, clock ? GST_STR_NULL (GST_OBJECT_NAME (clock)) : "-");
630 * gst_pipeline_get_clock:
631 * @pipeline: a #GstPipeline
633 * Gets the current clock used by @pipeline.
635 * Returns: (transfer full): a #GstClock, unref after usage.
638 gst_pipeline_get_clock (GstPipeline * pipeline)
640 g_return_val_if_fail (GST_IS_PIPELINE (pipeline), NULL);
642 return gst_pipeline_provide_clock_func (GST_ELEMENT_CAST (pipeline));
647 * gst_pipeline_use_clock:
648 * @pipeline: a #GstPipeline
649 * @clock: (transfer none) (allow-none): the clock to use
651 * Force @pipeline to use the given @clock. The pipeline will
652 * always use the given clock even if new clock providers are added
655 * If @clock is %NULL all clocking will be disabled which will make
656 * the pipeline run as fast as possible.
661 gst_pipeline_use_clock (GstPipeline * pipeline, GstClock * clock)
665 g_return_if_fail (GST_IS_PIPELINE (pipeline));
667 GST_OBJECT_LOCK (pipeline);
668 GST_OBJECT_FLAG_SET (pipeline, GST_PIPELINE_FLAG_FIXED_CLOCK);
670 clock_p = &pipeline->fixed_clock;
671 gst_object_replace ((GstObject **) clock_p, (GstObject *) clock);
672 GST_OBJECT_UNLOCK (pipeline);
674 GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline using fixed clock %p (%s)", clock,
675 (clock ? GST_OBJECT_NAME (clock) : "nil"));
679 * gst_pipeline_set_clock:
680 * @pipeline: a #GstPipeline
681 * @clock: (transfer none): the clock to set
683 * Set the clock for @pipeline. The clock will be distributed
684 * to all the elements managed by the pipeline.
686 * Returns: %TRUE if the clock could be set on the pipeline. %FALSE if
687 * some element did not accept the clock.
692 gst_pipeline_set_clock (GstPipeline * pipeline, GstClock * clock)
694 g_return_val_if_fail (pipeline != NULL, FALSE);
695 g_return_val_if_fail (GST_IS_PIPELINE (pipeline), FALSE);
698 GST_ELEMENT_CLASS (parent_class)->set_clock (GST_ELEMENT_CAST (pipeline),
703 * gst_pipeline_auto_clock:
704 * @pipeline: a #GstPipeline
706 * Let @pipeline select a clock automatically. This is the default
709 * Use this function if you previous forced a fixed clock with
710 * gst_pipeline_use_clock() and want to restore the default
711 * pipeline clock selection algorithm.
716 gst_pipeline_auto_clock (GstPipeline * pipeline)
720 g_return_if_fail (pipeline != NULL);
721 g_return_if_fail (GST_IS_PIPELINE (pipeline));
723 GST_OBJECT_LOCK (pipeline);
724 GST_OBJECT_FLAG_UNSET (pipeline, GST_PIPELINE_FLAG_FIXED_CLOCK);
726 clock_p = &pipeline->fixed_clock;
727 gst_object_replace ((GstObject **) clock_p, NULL);
728 GST_OBJECT_UNLOCK (pipeline);
730 GST_CAT_DEBUG (GST_CAT_CLOCK, "pipeline using automatic clock");
734 * gst_pipeline_set_delay:
735 * @pipeline: a #GstPipeline
738 * Set the expected delay needed for all elements to perform the
739 * PAUSED to PLAYING state change. @delay will be added to the
740 * base time of the elements so that they wait an additional @delay
741 * amount of time before starting to process buffers and cannot be
742 * #GST_CLOCK_TIME_NONE.
744 * This option is used for tuning purposes and should normally not be
750 gst_pipeline_set_delay (GstPipeline * pipeline, GstClockTime delay)
752 g_return_if_fail (GST_IS_PIPELINE (pipeline));
753 g_return_if_fail (delay != GST_CLOCK_TIME_NONE);
755 GST_OBJECT_LOCK (pipeline);
756 pipeline->delay = delay;
757 GST_OBJECT_UNLOCK (pipeline);
761 * gst_pipeline_get_delay:
762 * @pipeline: a #GstPipeline
764 * Get the configured delay (see gst_pipeline_set_delay()).
766 * Returns: The configured delay.
771 gst_pipeline_get_delay (GstPipeline * pipeline)
775 g_return_val_if_fail (GST_IS_PIPELINE (pipeline), GST_CLOCK_TIME_NONE);
777 GST_OBJECT_LOCK (pipeline);
778 res = pipeline->delay;
779 GST_OBJECT_UNLOCK (pipeline);
785 * gst_pipeline_set_auto_flush_bus:
786 * @pipeline: a #GstPipeline
787 * @auto_flush: whether or not to automatically flush the bus when
788 * the pipeline goes from READY to NULL state
790 * Usually, when a pipeline goes from READY to NULL state, it automatically
791 * flushes all pending messages on the bus, which is done for refcounting
792 * purposes, to break circular references.
794 * This means that applications that update state using (async) bus messages
795 * (e.g. do certain things when a pipeline goes from PAUSED to READY) might
796 * not get to see messages when the pipeline is shut down, because they might
797 * be flushed before they can be dispatched in the main thread. This behaviour
798 * can be disabled using this function.
800 * It is important that all messages on the bus are handled when the
801 * automatic flushing is disabled else memory leaks will be introduced.
806 gst_pipeline_set_auto_flush_bus (GstPipeline * pipeline, gboolean auto_flush)
808 g_return_if_fail (GST_IS_PIPELINE (pipeline));
810 GST_OBJECT_LOCK (pipeline);
811 pipeline->priv->auto_flush_bus = auto_flush;
812 GST_OBJECT_UNLOCK (pipeline);
816 * gst_pipeline_get_auto_flush_bus:
817 * @pipeline: a #GstPipeline
819 * Check if @pipeline will automatically flush messages when going to
822 * Returns: whether the pipeline will automatically flush its bus when
823 * going from READY to NULL state or not.
828 gst_pipeline_get_auto_flush_bus (GstPipeline * pipeline)
832 g_return_val_if_fail (GST_IS_PIPELINE (pipeline), FALSE);
834 GST_OBJECT_LOCK (pipeline);
835 res = pipeline->priv->auto_flush_bus;
836 GST_OBJECT_UNLOCK (pipeline);