2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2004 Wim Taymans <wim@fluendo.com>
6 * gstclock.c: Clock subsystem for maintaining time sync
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., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
27 * @short_description: Abstract class for global clocks
28 * @see_also: #GstSystemClock, #GstPipeline
30 * GStreamer uses a global clock to synchronize the plugins in a pipeline.
31 * Different clock implementations are possible by implementing this abstract
32 * base class or, more conveniently, by subclassing #GstSystemClock.
34 * The #GstClock returns a monotonically increasing time with the method
35 * gst_clock_get_time(). Its accuracy and base time depend on the specific
36 * clock implementation but time is always expressed in nanoseconds. Since the
37 * baseline of the clock is undefined, the clock time returned is not
38 * meaningful in itself, what matters are the deltas between two clock times.
39 * The time returned by a clock is called the absolute time.
41 * The pipeline uses the clock to calculate the running time. Usually all
42 * renderers synchronize to the global clock using the buffer timestamps, the
43 * newsegment events and the element's base time, see #GstPipeline.
45 * A clock implementation can support periodic and single shot clock
46 * notifications both synchronous and asynchronous.
48 * One first needs to create a #GstClockID for the periodic or single shot
49 * notification using gst_clock_new_single_shot_id() or
50 * gst_clock_new_periodic_id().
52 * To perform a blocking wait for the specific time of the #GstClockID use the
53 * gst_clock_id_wait(). To receive a callback when the specific time is reached
54 * in the clock use gst_clock_id_wait_async(). Both these calls can be
55 * interrupted with the gst_clock_id_unschedule() call. If the blocking wait is
56 * unscheduled a return value of #GST_CLOCK_UNSCHEDULED is returned.
58 * Periodic callbacks scheduled async will be repeatedly called automatically
59 * until it is unscheduled. To schedule a sync periodic callback,
60 * gst_clock_id_wait() should be called repeatedly.
62 * The async callbacks can happen from any thread, either provided by the core
63 * or from a streaming thread. The application should be prepared for this.
65 * A #GstClockID that has been unscheduled cannot be used again for any wait
66 * operation, a new #GstClockID should be created and the old unscheduled one
67 * should be destroyed with gst_clock_id_unref().
69 * It is possible to perform a blocking wait on the same #GstClockID from
70 * multiple threads. However, registering the same #GstClockID for multiple
71 * async notifications is not possible, the callback will only be called for
72 * the thread registering the entry last.
74 * None of the wait operations unref the #GstClockID, the owner is responsible
75 * for unreffing the ids itself. This holds for both periodic and single shot
76 * notifications. The reason being that the owner of the #GstClockID has to
77 * keep a handle to the #GstClockID to unblock the wait on FLUSHING events or
78 * state changes and if the entry would be unreffed automatically, the handle
79 * might become invalid without any notification.
81 * These clock operations do not operate on the running time, so the callbacks
82 * will also occur when not in PLAYING state as if the clock just keeps on
83 * running. Some clocks however do not progress when the element that provided
84 * the clock is not PLAYING.
86 * When a clock has the #GST_CLOCK_FLAG_CAN_SET_MASTER flag set, it can be
87 * slaved to another #GstClock with the gst_clock_set_master(). The clock will
88 * then automatically be synchronized to this master clock by repeatedly
89 * sampling the master clock and the slave clock and recalibrating the slave
90 * clock with gst_clock_set_calibration(). This feature is mostly useful for
91 * plugins that have an internal clock but must operate with another clock
92 * selected by the #GstPipeline. They can track the offset and rate difference
93 * of their internal clock relative to the master clock by using the
94 * gst_clock_get_calibration() function.
96 * The master/slave synchronisation can be tuned with the #GstClock:timeout,
97 * #GstClock:window-size and #GstClock:window-threshold properties.
98 * The #GstClock:timeout property defines the interval to sample the master
99 * clock and run the calibration functions. #GstClock:window-size defines the
100 * number of samples to use when calibrating and #GstClock:window-threshold
101 * defines the minimum number of samples before the calibration is performed.
104 #include "gst_private.h"
107 #include "gstclock.h"
109 #include "gstutils.h"
110 #include "glib-compat-private.h"
112 /* #define DEBUGGING_ENABLED */
114 #define DEFAULT_WINDOW_SIZE 32
115 #define DEFAULT_WINDOW_THRESHOLD 4
116 #define DEFAULT_TIMEOUT GST_SECOND / 10
122 PROP_WINDOW_THRESHOLD,
132 #define GST_CLOCK_SLAVE_LOCK(clock) g_mutex_lock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
133 #define GST_CLOCK_SLAVE_UNLOCK(clock) g_mutex_unlock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
135 struct _GstClockPrivate
137 GMutex slave_lock; /* order: SLAVE_LOCK, OBJECT_LOCK */
142 GstClockTime internal_calibration;
143 GstClockTime external_calibration;
144 GstClockTime rate_numerator;
145 GstClockTime rate_denominator;
146 GstClockTime last_time;
149 GstClockTime resolution;
151 /* for master/slave clocks */
154 /* with SLAVE_LOCK */
157 gint window_threshold;
159 GstClockTime timeout;
161 GstClockTime *times_temp;
171 #define read_seqbegin(clock) \
172 g_atomic_int_get (&clock->priv->post_count);
174 static inline gboolean
175 read_seqretry (GstClock * clock, gint seq)
177 /* no retry if the seqnum did not change */
178 if (G_LIKELY (seq == g_atomic_int_get (&clock->priv->pre_count)))
181 /* wait for the writer to finish and retry */
182 GST_OBJECT_LOCK (clock);
183 GST_OBJECT_UNLOCK (clock);
187 #define write_seqlock(clock) \
189 GST_OBJECT_LOCK (clock); \
190 g_atomic_int_inc (&clock->priv->pre_count); \
193 #define write_sequnlock(clock) \
195 g_atomic_int_inc (&clock->priv->post_count); \
196 GST_OBJECT_UNLOCK (clock); \
199 #ifndef GST_DISABLE_GST_DEBUG
201 gst_clock_return_get_name (GstClockReturn ret)
206 case GST_CLOCK_EARLY:
208 case GST_CLOCK_UNSCHEDULED:
209 return "unscheduled";
212 case GST_CLOCK_BADTIME:
214 case GST_CLOCK_ERROR:
216 case GST_CLOCK_UNSUPPORTED:
217 return "unsupported";
226 #endif /* GST_DISABLE_GST_DEBUG */
228 static void gst_clock_dispose (GObject * object);
229 static void gst_clock_finalize (GObject * object);
231 static void gst_clock_set_property (GObject * object, guint prop_id,
232 const GValue * value, GParamSpec * pspec);
233 static void gst_clock_get_property (GObject * object, guint prop_id,
234 GValue * value, GParamSpec * pspec);
236 static guint gst_clock_signals[SIGNAL_LAST] = { 0 };
239 gst_clock_entry_new (GstClock * clock, GstClockTime time,
240 GstClockTime interval, GstClockEntryType type)
242 GstClockEntry *entry;
244 entry = g_slice_new (GstClockEntry);
246 /* FIXME: add tracer hook for struct allocations such as clock entries */
248 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
249 "created entry %p, time %" GST_TIME_FORMAT, entry, GST_TIME_ARGS (time));
252 entry->clock = clock;
255 entry->interval = interval;
256 entry->status = GST_CLOCK_OK;
258 entry->user_data = NULL;
259 entry->destroy_data = NULL;
260 entry->unscheduled = FALSE;
261 entry->woken_up = FALSE;
263 return (GstClockID) entry;
266 /* WARNING : Does not modify the refcount
267 * WARNING : Do not use if a pending clock operation is happening on that entry */
269 gst_clock_entry_reinit (GstClock * clock, GstClockEntry * entry,
270 GstClockTime time, GstClockTime interval, GstClockEntryType type)
272 g_return_val_if_fail (entry->status != GST_CLOCK_BUSY, FALSE);
273 g_return_val_if_fail (entry->clock == clock, FALSE);
277 entry->interval = interval;
278 entry->status = GST_CLOCK_OK;
279 entry->unscheduled = FALSE;
280 entry->woken_up = FALSE;
286 * gst_clock_single_shot_id_reinit:
287 * @clock: a #GstClock
289 * @time: The requested time.
291 * Reinitializes the provided single shot @id to the provided time. Does not
292 * modify the reference count.
294 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
295 * @time, else %FALSE.
298 gst_clock_single_shot_id_reinit (GstClock * clock, GstClockID id,
301 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, time,
302 GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
306 * gst_clock_periodic_id_reinit:
307 * @clock: a #GstClock
309 * @start_time: the requested start time
310 * @interval: the requested interval
312 * Reinitializes the provided periodic @id to the provided start time and
313 * interval. Does not modify the reference count.
315 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
316 * @time, else %FALSE.
319 gst_clock_periodic_id_reinit (GstClock * clock, GstClockID id,
320 GstClockTime start_time, GstClockTime interval)
322 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, start_time,
323 interval, GST_CLOCK_ENTRY_PERIODIC);
328 * @id: The #GstClockID to ref
330 * Increase the refcount of given @id.
332 * Returns: (transfer full): The same #GstClockID with increased refcount.
337 gst_clock_id_ref (GstClockID id)
339 g_return_val_if_fail (id != NULL, NULL);
341 g_atomic_int_inc (&((GstClockEntry *) id)->refcount);
347 _gst_clock_id_free (GstClockID id)
349 GstClockEntry *entry;
350 g_return_if_fail (id != NULL);
352 GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);
353 entry = (GstClockEntry *) id;
354 if (entry->destroy_data)
355 entry->destroy_data (entry->user_data);
357 /* FIXME: add tracer hook for struct allocations such as clock entries */
359 g_slice_free (GstClockEntry, id);
363 * gst_clock_id_unref:
364 * @id: (transfer full): The #GstClockID to unref
366 * Unref given @id. When the refcount reaches 0 the
367 * #GstClockID will be freed.
372 gst_clock_id_unref (GstClockID id)
376 g_return_if_fail (id != NULL);
378 zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);
379 /* if we ended up with the refcount at zero, free the id */
381 _gst_clock_id_free (id);
386 * gst_clock_new_single_shot_id:
387 * @clock: The #GstClockID to get a single shot notification from
388 * @time: the requested time
390 * Get a #GstClockID from @clock to trigger a single shot
391 * notification at the requested time. The single shot id should be
392 * unreffed after usage.
394 * Free-function: gst_clock_id_unref
396 * Returns: (transfer full): a #GstClockID that can be used to request the
402 gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)
404 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
406 return gst_clock_entry_new (clock,
407 time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
411 * gst_clock_new_periodic_id:
412 * @clock: The #GstClockID to get a periodic notification id from
413 * @start_time: the requested start time
414 * @interval: the requested interval
416 * Get an ID from @clock to trigger a periodic notification.
417 * The periodic notifications will start at time @start_time and
418 * will then be fired with the given @interval. @id should be unreffed
421 * Free-function: gst_clock_id_unref
423 * Returns: (transfer full): a #GstClockID that can be used to request the
429 gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,
430 GstClockTime interval)
432 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
433 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);
434 g_return_val_if_fail (interval != 0, NULL);
435 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);
437 return gst_clock_entry_new (clock,
438 start_time, interval, GST_CLOCK_ENTRY_PERIODIC);
442 * gst_clock_id_compare_func:
443 * @id1: A #GstClockID
444 * @id2: A #GstClockID to compare with
446 * Compares the two #GstClockID instances. This function can be used
447 * as a GCompareFunc when sorting ids.
449 * Returns: negative value if a < b; zero if a = b; positive value if a > b
454 gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)
456 GstClockEntry *entry1, *entry2;
458 entry1 = (GstClockEntry *) id1;
459 entry2 = (GstClockEntry *) id2;
461 if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {
464 if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {
471 * gst_clock_id_get_time:
472 * @id: The #GstClockID to query
474 * Get the time of the clock ID
476 * Returns: the time of the given clock id.
481 gst_clock_id_get_time (GstClockID id)
483 g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
485 return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);
490 * @id: The #GstClockID to wait on
491 * @jitter: (out) (allow-none): a pointer that will contain the jitter,
494 * Perform a blocking wait on @id.
495 * @id should have been created with gst_clock_new_single_shot_id()
496 * or gst_clock_new_periodic_id() and should not have been unscheduled
497 * with a call to gst_clock_id_unschedule().
499 * If the @jitter argument is not %NULL and this function returns #GST_CLOCK_OK
500 * or #GST_CLOCK_EARLY, it will contain the difference
501 * against the clock and the time of @id when this method was
503 * Positive values indicate how late @id was relative to the clock
504 * (in which case this function will return #GST_CLOCK_EARLY).
505 * Negative values indicate how much time was spent waiting on the clock
506 * before this function returned.
508 * Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned
509 * if the current clock time is past the time of @id, #GST_CLOCK_OK if
510 * @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was
511 * unscheduled with gst_clock_id_unschedule().
516 gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)
518 GstClockEntry *entry;
521 GstClockTime requested;
522 GstClockClass *cclass;
524 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
526 entry = (GstClockEntry *) id;
527 requested = GST_CLOCK_ENTRY_TIME (entry);
529 clock = GST_CLOCK_ENTRY_CLOCK (entry);
531 /* can't sync on invalid times */
532 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
535 cclass = GST_CLOCK_GET_CLASS (clock);
537 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);
539 /* if we have a wait_jitter function, use that */
540 if (G_UNLIKELY (cclass->wait == NULL))
543 res = cclass->wait (clock, entry, jitter);
545 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
546 "done waiting entry %p, res: %d (%s)", id, res,
547 gst_clock_return_get_name (res));
549 if (entry->type == GST_CLOCK_ENTRY_PERIODIC)
550 entry->time = requested + entry->interval;
557 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
558 "invalid time requested, returning _BADTIME");
559 return GST_CLOCK_BADTIME;
563 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
564 return GST_CLOCK_UNSUPPORTED;
569 * gst_clock_id_wait_async:
570 * @id: a #GstClockID to wait on
571 * @func: The callback function
572 * @user_data: User data passed in the callback
573 * @destroy_data: #GDestroyNotify for user_data
575 * Register a callback on the given #GstClockID @id with the given
576 * function and user_data. When passing a #GstClockID with an invalid
577 * time to this function, the callback will be called immediately
578 * with a time set to GST_CLOCK_TIME_NONE. The callback will
579 * be called when the time of @id has been reached.
581 * The callback @func can be invoked from any thread, either provided by the
582 * core or from a streaming thread. The application should be prepared for this.
584 * Returns: the result of the non blocking wait.
589 gst_clock_id_wait_async (GstClockID id,
590 GstClockCallback func, gpointer user_data, GDestroyNotify destroy_data)
592 GstClockEntry *entry;
595 GstClockClass *cclass;
596 GstClockTime requested;
598 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
599 g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
601 entry = (GstClockEntry *) id;
602 requested = GST_CLOCK_ENTRY_TIME (entry);
603 clock = GST_CLOCK_ENTRY_CLOCK (entry);
605 /* can't sync on invalid times */
606 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
609 cclass = GST_CLOCK_GET_CLASS (clock);
611 if (G_UNLIKELY (cclass->wait_async == NULL))
615 entry->user_data = user_data;
616 entry->destroy_data = destroy_data;
618 res = cclass->wait_async (clock, entry);
625 (func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
626 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
627 "invalid time requested, returning _BADTIME");
628 return GST_CLOCK_BADTIME;
632 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
633 return GST_CLOCK_UNSUPPORTED;
638 * gst_clock_id_unschedule:
639 * @id: The id to unschedule
641 * Cancel an outstanding request with @id. This can either
642 * be an outstanding async notification or a pending sync notification.
643 * After this call, @id cannot be used anymore to receive sync or
644 * async notifications, you need to create a new #GstClockID.
649 gst_clock_id_unschedule (GstClockID id)
651 GstClockEntry *entry;
653 GstClockClass *cclass;
655 g_return_if_fail (id != NULL);
657 entry = (GstClockEntry *) id;
658 clock = entry->clock;
660 cclass = GST_CLOCK_GET_CLASS (clock);
662 if (G_LIKELY (cclass->unschedule))
663 cclass->unschedule (clock, entry);
668 * GstClock abstract base class implementation
670 #define gst_clock_parent_class parent_class
671 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GstClock, gst_clock, GST_TYPE_OBJECT);
674 gst_clock_class_init (GstClockClass * klass)
676 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
678 gobject_class->dispose = gst_clock_dispose;
679 gobject_class->finalize = gst_clock_finalize;
680 gobject_class->set_property = gst_clock_set_property;
681 gobject_class->get_property = gst_clock_get_property;
683 g_object_class_install_property (gobject_class, PROP_WINDOW_SIZE,
684 g_param_spec_int ("window-size", "Window size",
685 "The size of the window used to calculate rate and offset", 2, 1024,
686 DEFAULT_WINDOW_SIZE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
687 g_object_class_install_property (gobject_class, PROP_WINDOW_THRESHOLD,
688 g_param_spec_int ("window-threshold", "Window threshold",
689 "The threshold to start calculating rate and offset", 2, 1024,
690 DEFAULT_WINDOW_THRESHOLD,
691 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
692 g_object_class_install_property (gobject_class, PROP_TIMEOUT,
693 g_param_spec_uint64 ("timeout", "Timeout",
694 "The amount of time, in nanoseconds, to sample master and slave clocks",
695 0, G_MAXUINT64, DEFAULT_TIMEOUT,
696 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
701 * @synced: if the clock is synced now
703 * Signaled on clocks with GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC set once
704 * the clock is synchronized, or when it completely lost synchronization.
705 * This signal will not be emitted on clocks without the flag.
707 * This signal will be emitted from an arbitrary thread, most likely not
708 * the application's main thread.
712 gst_clock_signals[SIGNAL_SYNCED] =
713 g_signal_new ("synced", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
715 g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_BOOLEAN);
719 gst_clock_init (GstClock * clock)
721 GstClockPrivate *priv;
723 clock->priv = priv = gst_clock_get_instance_private (clock);
727 priv->internal_calibration = 0;
728 priv->external_calibration = 0;
729 priv->rate_numerator = 1;
730 priv->rate_denominator = 1;
732 g_mutex_init (&priv->slave_lock);
733 g_cond_init (&priv->sync_cond);
734 priv->window_size = DEFAULT_WINDOW_SIZE;
735 priv->window_threshold = DEFAULT_WINDOW_THRESHOLD;
736 priv->filling = TRUE;
737 priv->time_index = 0;
738 priv->timeout = DEFAULT_TIMEOUT;
739 priv->times = g_new0 (GstClockTime, 4 * priv->window_size);
740 priv->times_temp = priv->times + 2 * priv->window_size;
744 gst_clock_dispose (GObject * object)
746 GstClock *clock = GST_CLOCK (object);
749 GST_OBJECT_LOCK (clock);
750 master_p = &clock->priv->master;
751 gst_object_replace ((GstObject **) master_p, NULL);
752 GST_OBJECT_UNLOCK (clock);
754 G_OBJECT_CLASS (parent_class)->dispose (object);
758 gst_clock_finalize (GObject * object)
760 GstClock *clock = GST_CLOCK (object);
762 GST_CLOCK_SLAVE_LOCK (clock);
763 if (clock->priv->clockid) {
764 gst_clock_id_unschedule (clock->priv->clockid);
765 gst_clock_id_unref (clock->priv->clockid);
766 clock->priv->clockid = NULL;
768 g_free (clock->priv->times);
769 clock->priv->times = NULL;
770 clock->priv->times_temp = NULL;
771 GST_CLOCK_SLAVE_UNLOCK (clock);
773 g_mutex_clear (&clock->priv->slave_lock);
774 g_cond_clear (&clock->priv->sync_cond);
776 G_OBJECT_CLASS (parent_class)->finalize (object);
780 * gst_clock_set_resolution:
781 * @clock: a #GstClock
782 * @resolution: The resolution to set
784 * Set the accuracy of the clock. Some clocks have the possibility to operate
785 * with different accuracy at the expense of more resource usage. There is
786 * normally no need to change the default resolution of a clock. The resolution
787 * of a clock can only be changed if the clock has the
788 * #GST_CLOCK_FLAG_CAN_SET_RESOLUTION flag set.
790 * Returns: the new resolution of the clock.
793 gst_clock_set_resolution (GstClock * clock, GstClockTime resolution)
795 GstClockPrivate *priv;
796 GstClockClass *cclass;
798 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
799 g_return_val_if_fail (resolution != 0, 0);
801 cclass = GST_CLOCK_GET_CLASS (clock);
804 if (cclass->change_resolution)
806 cclass->change_resolution (clock, priv->resolution, resolution);
808 return priv->resolution;
812 * gst_clock_get_resolution:
813 * @clock: a #GstClock
815 * Get the accuracy of the clock. The accuracy of the clock is the granularity
816 * of the values returned by gst_clock_get_time().
818 * Returns: the resolution of the clock in units of #GstClockTime.
823 gst_clock_get_resolution (GstClock * clock)
825 GstClockClass *cclass;
827 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
829 cclass = GST_CLOCK_GET_CLASS (clock);
831 if (cclass->get_resolution)
832 return cclass->get_resolution (clock);
837 /* FIXME 2.0: Remove clock parameter below */
839 * gst_clock_adjust_with_calibration:
840 * @clock: (allow-none): a #GstClock to use
841 * @internal_target: a clock time
842 * @cinternal: a reference internal time
843 * @cexternal: a reference external time
844 * @cnum: the numerator of the rate of the clock relative to its
846 * @cdenom: the denominator of the rate of the clock
848 * Converts the given @internal_target clock time to the external time,
849 * using the passed calibration parameters. This function performs the
850 * same calculation as gst_clock_adjust_unlocked() when called using the
851 * current calibration parameters, but doesn't ensure a monotonically
852 * increasing result as gst_clock_adjust_unlocked() does.
854 * Note: The @clock parameter is unused and can be NULL
856 * Returns: the converted time of the clock.
861 gst_clock_adjust_with_calibration (GstClock * clock,
862 GstClockTime internal_target, GstClockTime cinternal,
863 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
867 /* avoid divide by 0 */
868 if (G_UNLIKELY (cdenom == 0))
871 /* The formula is (internal - cinternal) * cnum / cdenom + cexternal
873 * Since we do math on unsigned 64-bit ints we have to special case for
874 * internal < cinternal to get the sign right. this case is not very common,
877 if (G_LIKELY (internal_target >= cinternal)) {
878 ret = internal_target - cinternal;
879 ret = gst_util_uint64_scale (ret, cnum, cdenom);
882 ret = cinternal - internal_target;
883 ret = gst_util_uint64_scale (ret, cnum, cdenom);
885 if (G_LIKELY (cexternal > ret))
886 ret = cexternal - ret;
895 * gst_clock_adjust_unlocked:
896 * @clock: a #GstClock to use
897 * @internal: a clock time
899 * Converts the given @internal clock time to the external time, adjusting for the
900 * rate and reference time set with gst_clock_set_calibration() and making sure
901 * that the returned time is increasing. This function should be called with the
902 * clock's OBJECT_LOCK held and is mainly used by clock subclasses.
904 * This function is the reverse of gst_clock_unadjust_unlocked().
906 * Returns: the converted time of the clock.
909 gst_clock_adjust_unlocked (GstClock * clock, GstClockTime internal)
911 GstClockTime ret, cinternal, cexternal, cnum, cdenom;
912 GstClockPrivate *priv = clock->priv;
914 /* get calibration values for readability */
915 cinternal = priv->internal_calibration;
916 cexternal = priv->external_calibration;
917 cnum = priv->rate_numerator;
918 cdenom = priv->rate_denominator;
921 gst_clock_adjust_with_calibration (clock, internal, cinternal, cexternal,
924 /* make sure the time is increasing */
925 priv->last_time = MAX (ret, priv->last_time);
927 return priv->last_time;
930 /* FIXME 2.0: Remove clock parameter below */
932 * gst_clock_unadjust_with_calibration:
933 * @clock: (allow-none): a #GstClock to use
934 * @external_target: a clock time
935 * @cinternal: a reference internal time
936 * @cexternal: a reference external time
937 * @cnum: the numerator of the rate of the clock relative to its
939 * @cdenom: the denominator of the rate of the clock
941 * Converts the given @external_target clock time to the internal time,
942 * using the passed calibration parameters. This function performs the
943 * same calculation as gst_clock_unadjust_unlocked() when called using the
944 * current calibration parameters.
946 * Note: The @clock parameter is unused and can be NULL
948 * Returns: the converted time of the clock.
953 gst_clock_unadjust_with_calibration (GstClock * clock,
954 GstClockTime external_target, GstClockTime cinternal,
955 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
959 /* avoid divide by 0 */
960 if (G_UNLIKELY (cnum == 0))
963 /* The formula is (external - cexternal) * cdenom / cnum + cinternal */
964 if (G_LIKELY (external_target >= cexternal)) {
965 ret = external_target - cexternal;
966 ret = gst_util_uint64_scale (ret, cdenom, cnum);
969 ret = cexternal - external_target;
970 ret = gst_util_uint64_scale (ret, cdenom, cnum);
971 if (G_LIKELY (cinternal > ret))
972 ret = cinternal - ret;
981 * gst_clock_unadjust_unlocked:
982 * @clock: a #GstClock to use
983 * @external: an external clock time
985 * Converts the given @external clock time to the internal time of @clock,
986 * using the rate and reference time set with gst_clock_set_calibration().
987 * This function should be called with the clock's OBJECT_LOCK held and
988 * is mainly used by clock subclasses.
990 * This function is the reverse of gst_clock_adjust_unlocked().
992 * Returns: the internal time of the clock corresponding to @external.
995 gst_clock_unadjust_unlocked (GstClock * clock, GstClockTime external)
997 GstClockTime cinternal, cexternal, cnum, cdenom;
998 GstClockPrivate *priv = clock->priv;
1000 /* get calibration values for readability */
1001 cinternal = priv->internal_calibration;
1002 cexternal = priv->external_calibration;
1003 cnum = priv->rate_numerator;
1004 cdenom = priv->rate_denominator;
1006 return gst_clock_unadjust_with_calibration (clock, external, cinternal,
1007 cexternal, cnum, cdenom);
1011 * gst_clock_get_internal_time:
1012 * @clock: a #GstClock to query
1014 * Gets the current internal time of the given clock. The time is returned
1015 * unadjusted for the offset and the rate.
1017 * Returns: the internal time of the clock. Or GST_CLOCK_TIME_NONE when
1018 * given invalid input.
1023 gst_clock_get_internal_time (GstClock * clock)
1026 GstClockClass *cclass;
1028 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1030 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (clock,
1031 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC) && !clock->priv->synced))
1032 GST_CAT_WARNING_OBJECT (GST_CAT_CLOCK, clock,
1033 "clock is not synchronized yet");
1035 cclass = GST_CLOCK_GET_CLASS (clock);
1037 if (G_UNLIKELY (cclass->get_internal_time == NULL))
1040 ret = cclass->get_internal_time (clock);
1042 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "internal time %" GST_TIME_FORMAT,
1043 GST_TIME_ARGS (ret));
1050 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1051 "internal time not supported, return 0");
1052 return G_GINT64_CONSTANT (0);
1057 * gst_clock_get_time:
1058 * @clock: a #GstClock to query
1060 * Gets the current time of the given clock. The time is always
1061 * monotonically increasing and adjusted according to the current
1064 * Returns: the time of the clock. Or GST_CLOCK_TIME_NONE when
1065 * given invalid input.
1070 gst_clock_get_time (GstClock * clock)
1075 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1078 /* reget the internal time when we retry to get the most current
1080 ret = gst_clock_get_internal_time (clock);
1082 seq = read_seqbegin (clock);
1083 /* this will scale for rate and offset */
1084 ret = gst_clock_adjust_unlocked (clock, ret);
1085 } while (read_seqretry (clock, seq));
1087 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "adjusted time %" GST_TIME_FORMAT,
1088 GST_TIME_ARGS (ret));
1094 * gst_clock_set_calibration:
1095 * @clock: a #GstClock to calibrate
1096 * @internal: a reference internal time
1097 * @external: a reference external time
1098 * @rate_num: the numerator of the rate of the clock relative to its
1100 * @rate_denom: the denominator of the rate of the clock
1102 * Adjusts the rate and time of @clock. A rate of 1/1 is the normal speed of
1103 * the clock. Values bigger than 1/1 make the clock go faster.
1105 * @internal and @external are calibration parameters that arrange that
1106 * gst_clock_get_time() should have been @external at internal time @internal.
1107 * This internal time should not be in the future; that is, it should be less
1108 * than the value of gst_clock_get_internal_time() when this function is called.
1110 * Subsequent calls to gst_clock_get_time() will return clock times computed as
1114 * time = (internal_time - internal) * rate_num / rate_denom + external
1117 * This formula is implemented in gst_clock_adjust_unlocked(). Of course, it
1118 * tries to do the integer arithmetic as precisely as possible.
1120 * Note that gst_clock_get_time() always returns increasing values so when you
1121 * move the clock backwards, gst_clock_get_time() will report the previous value
1122 * until the clock catches up.
1127 gst_clock_set_calibration (GstClock * clock, GstClockTime internal, GstClockTime
1128 external, GstClockTime rate_num, GstClockTime rate_denom)
1130 GstClockPrivate *priv;
1132 g_return_if_fail (GST_IS_CLOCK (clock));
1133 g_return_if_fail (rate_num != GST_CLOCK_TIME_NONE);
1134 g_return_if_fail (rate_denom > 0 && rate_denom != GST_CLOCK_TIME_NONE);
1138 write_seqlock (clock);
1139 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1140 "internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT " %"
1141 G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT " = %f", GST_TIME_ARGS (internal),
1142 GST_TIME_ARGS (external), rate_num, rate_denom,
1143 gst_guint64_to_gdouble (rate_num) / gst_guint64_to_gdouble (rate_denom));
1145 priv->internal_calibration = internal;
1146 priv->external_calibration = external;
1147 priv->rate_numerator = rate_num;
1148 priv->rate_denominator = rate_denom;
1149 write_sequnlock (clock);
1153 * gst_clock_get_calibration:
1154 * @clock: a #GstClock
1155 * @internal: (out) (allow-none): a location to store the internal time
1156 * @external: (out) (allow-none): a location to store the external time
1157 * @rate_num: (out) (allow-none): a location to store the rate numerator
1158 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1160 * Gets the internal rate and reference time of @clock. See
1161 * gst_clock_set_calibration() for more information.
1163 * @internal, @external, @rate_num, and @rate_denom can be left %NULL if the
1164 * caller is not interested in the values.
1169 gst_clock_get_calibration (GstClock * clock, GstClockTime * internal,
1170 GstClockTime * external, GstClockTime * rate_num, GstClockTime * rate_denom)
1173 GstClockPrivate *priv;
1175 g_return_if_fail (GST_IS_CLOCK (clock));
1180 seq = read_seqbegin (clock);
1182 *rate_num = priv->rate_numerator;
1184 *rate_denom = priv->rate_denominator;
1186 *external = priv->external_calibration;
1188 *internal = priv->internal_calibration;
1189 } while (read_seqretry (clock, seq));
1192 /* will be called repeatedly to sample the master and slave clock
1193 * to recalibrate the clock */
1195 gst_clock_slave_callback (GstClock * master, GstClockTime time,
1196 GstClockID id, GstClock * clock)
1198 GstClockTime stime, mtime;
1201 if (!gst_clock_is_synced (clock)) {
1202 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1203 "Slave clock is not synced yet");
1207 stime = gst_clock_get_internal_time (clock);
1208 mtime = gst_clock_get_time (master);
1210 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1211 "master %" GST_TIME_FORMAT ", slave %" GST_TIME_FORMAT,
1212 GST_TIME_ARGS (mtime), GST_TIME_ARGS (stime));
1214 gst_clock_add_observation (clock, stime, mtime, &r_squared);
1216 /* FIXME, we can use the r_squared value to adjust the timeout
1217 * value of the clockid */
1223 * gst_clock_set_master:
1224 * @clock: a #GstClock
1225 * @master: (allow-none): a master #GstClock
1227 * Set @master as the master clock for @clock. @clock will be automatically
1228 * calibrated so that gst_clock_get_time() reports the same time as the
1231 * A clock provider that slaves its clock to a master can get the current
1232 * calibration values with gst_clock_get_calibration().
1234 * @master can be %NULL in which case @clock will not be slaved anymore. It will
1235 * however keep reporting its time adjusted with the last configured rate
1238 * Returns: %TRUE if the clock is capable of being slaved to a master clock.
1239 * Trying to set a master on a clock without the
1240 * #GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return %FALSE.
1245 gst_clock_set_master (GstClock * clock, GstClock * master)
1247 GstClock **master_p;
1248 GstClockPrivate *priv;
1250 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1251 g_return_val_if_fail (master != clock, FALSE);
1253 GST_OBJECT_LOCK (clock);
1254 /* we always allow setting the master to NULL */
1255 if (master && !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER))
1257 if (master && !gst_clock_is_synced (master))
1258 goto master_not_synced;
1260 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1261 "slaving %p to master clock %p", clock, master);
1262 GST_OBJECT_UNLOCK (clock);
1266 GST_CLOCK_SLAVE_LOCK (clock);
1267 if (priv->clockid) {
1268 gst_clock_id_unschedule (priv->clockid);
1269 gst_clock_id_unref (priv->clockid);
1270 priv->clockid = NULL;
1273 priv->filling = TRUE;
1274 priv->time_index = 0;
1275 /* use the master periodic id to schedule sampling and
1276 * clock calibration. */
1277 priv->clockid = gst_clock_new_periodic_id (master,
1278 gst_clock_get_time (master), priv->timeout);
1279 gst_clock_id_wait_async (priv->clockid,
1280 (GstClockCallback) gst_clock_slave_callback,
1281 gst_object_ref (clock), (GDestroyNotify) gst_object_unref);
1283 GST_CLOCK_SLAVE_UNLOCK (clock);
1285 GST_OBJECT_LOCK (clock);
1286 master_p = &priv->master;
1287 gst_object_replace ((GstObject **) master_p, (GstObject *) master);
1288 GST_OBJECT_UNLOCK (clock);
1295 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1296 "cannot be slaved to a master clock");
1297 GST_OBJECT_UNLOCK (clock);
1303 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, master,
1304 "master clock is not synced yet");
1305 GST_OBJECT_UNLOCK (clock);
1311 * gst_clock_get_master:
1312 * @clock: a #GstClock
1314 * Get the master clock that @clock is slaved to or %NULL when the clock is
1315 * not slaved to any master clock.
1317 * Returns: (transfer full) (nullable): a master #GstClock or %NULL
1318 * when this clock is not slaved to a master clock. Unref after
1324 gst_clock_get_master (GstClock * clock)
1326 GstClock *result = NULL;
1327 GstClockPrivate *priv;
1329 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
1333 GST_OBJECT_LOCK (clock);
1335 result = gst_object_ref (priv->master);
1336 GST_OBJECT_UNLOCK (clock);
1342 * gst_clock_add_observation:
1343 * @clock: a #GstClock
1344 * @slave: a time on the slave
1345 * @master: a time on the master
1346 * @r_squared: (out): a pointer to hold the result
1348 * The time @master of the master clock and the time @slave of the slave
1349 * clock are added to the list of observations. If enough observations
1350 * are available, a linear regression algorithm is run on the
1351 * observations and @clock is recalibrated.
1353 * If this functions returns %TRUE, @r_squared will contain the
1354 * correlation coefficient of the interpolation. A value of 1.0
1355 * means a perfect regression was performed. This value can
1356 * be used to control the sampling frequency of the master and slave
1359 * Returns: %TRUE if enough observations were added to run the
1360 * regression algorithm.
1365 gst_clock_add_observation (GstClock * clock, GstClockTime slave,
1366 GstClockTime master, gdouble * r_squared)
1368 GstClockTime m_num, m_denom, b, xbase;
1370 if (!gst_clock_add_observation_unapplied (clock, slave, master, r_squared,
1371 &xbase, &b, &m_num, &m_denom))
1374 /* if we have a valid regression, adjust the clock */
1375 gst_clock_set_calibration (clock, xbase, b, m_num, m_denom);
1381 * gst_clock_add_observation_unapplied:
1382 * @clock: a #GstClock
1383 * @slave: a time on the slave
1384 * @master: a time on the master
1385 * @r_squared: (out): a pointer to hold the result
1386 * @internal: (out) (allow-none): a location to store the internal time
1387 * @external: (out) (allow-none): a location to store the external time
1388 * @rate_num: (out) (allow-none): a location to store the rate numerator
1389 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1391 * Add a clock observation to the internal slaving algorithm the same as
1392 * gst_clock_add_observation(), and return the result of the master clock
1393 * estimation, without updating the internal calibration.
1395 * The caller can then take the results and call gst_clock_set_calibration()
1396 * with the values, or some modified version of them.
1401 gst_clock_add_observation_unapplied (GstClock * clock, GstClockTime slave,
1402 GstClockTime master, gdouble * r_squared,
1403 GstClockTime * internal, GstClockTime * external,
1404 GstClockTime * rate_num, GstClockTime * rate_denom)
1406 GstClockTime m_num, m_denom, b, xbase;
1407 GstClockPrivate *priv;
1410 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1411 g_return_val_if_fail (r_squared != NULL, FALSE);
1415 GST_CLOCK_SLAVE_LOCK (clock);
1417 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1418 "adding observation slave %" GST_TIME_FORMAT ", master %" GST_TIME_FORMAT,
1419 GST_TIME_ARGS (slave), GST_TIME_ARGS (master));
1421 priv->times[(2 * priv->time_index)] = slave;
1422 priv->times[(2 * priv->time_index) + 1] = master;
1425 if (G_UNLIKELY (priv->time_index == priv->window_size)) {
1426 priv->filling = FALSE;
1427 priv->time_index = 0;
1430 if (G_UNLIKELY (priv->filling && priv->time_index < priv->window_threshold))
1433 n = priv->filling ? priv->time_index : priv->window_size;
1434 if (!gst_calculate_linear_regression (priv->times, priv->times_temp, n,
1435 &m_num, &m_denom, &b, &xbase, r_squared))
1438 GST_CLOCK_SLAVE_UNLOCK (clock);
1440 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1441 "adjusting clock to m=%" G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT ", b=%"
1442 G_GUINT64_FORMAT " (rsquared=%g)", m_num, m_denom, b, *r_squared);
1451 *rate_denom = m_denom;
1457 GST_CLOCK_SLAVE_UNLOCK (clock);
1462 /* no valid regression has been done, ignore the result then */
1463 GST_CLOCK_SLAVE_UNLOCK (clock);
1469 * gst_clock_set_timeout:
1470 * @clock: a #GstClock
1471 * @timeout: a timeout
1473 * Set the amount of time, in nanoseconds, to sample master and slave
1477 gst_clock_set_timeout (GstClock * clock, GstClockTime timeout)
1479 g_return_if_fail (GST_IS_CLOCK (clock));
1481 GST_CLOCK_SLAVE_LOCK (clock);
1482 clock->priv->timeout = timeout;
1483 GST_CLOCK_SLAVE_UNLOCK (clock);
1487 * gst_clock_get_timeout:
1488 * @clock: a #GstClock
1490 * Get the amount of time that master and slave clocks are sampled.
1492 * Returns: the interval between samples.
1495 gst_clock_get_timeout (GstClock * clock)
1497 GstClockTime result;
1499 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1501 GST_CLOCK_SLAVE_LOCK (clock);
1502 result = clock->priv->timeout;
1503 GST_CLOCK_SLAVE_UNLOCK (clock);
1509 gst_clock_set_property (GObject * object, guint prop_id,
1510 const GValue * value, GParamSpec * pspec)
1513 GstClockPrivate *priv;
1515 clock = GST_CLOCK (object);
1519 case PROP_WINDOW_SIZE:
1520 GST_CLOCK_SLAVE_LOCK (clock);
1521 priv->window_size = g_value_get_int (value);
1522 priv->window_threshold = MIN (priv->window_threshold, priv->window_size);
1523 priv->times = g_renew (GstClockTime, priv->times, 4 * priv->window_size);
1524 priv->times_temp = priv->times + 2 * priv->window_size;
1525 /* restart calibration */
1526 priv->filling = TRUE;
1527 priv->time_index = 0;
1528 GST_CLOCK_SLAVE_UNLOCK (clock);
1530 case PROP_WINDOW_THRESHOLD:
1531 GST_CLOCK_SLAVE_LOCK (clock);
1532 priv->window_threshold = MIN (g_value_get_int (value), priv->window_size);
1533 GST_CLOCK_SLAVE_UNLOCK (clock);
1536 gst_clock_set_timeout (clock, g_value_get_uint64 (value));
1539 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1545 gst_clock_get_property (GObject * object, guint prop_id,
1546 GValue * value, GParamSpec * pspec)
1549 GstClockPrivate *priv;
1551 clock = GST_CLOCK (object);
1555 case PROP_WINDOW_SIZE:
1556 GST_CLOCK_SLAVE_LOCK (clock);
1557 g_value_set_int (value, priv->window_size);
1558 GST_CLOCK_SLAVE_UNLOCK (clock);
1560 case PROP_WINDOW_THRESHOLD:
1561 GST_CLOCK_SLAVE_LOCK (clock);
1562 g_value_set_int (value, priv->window_threshold);
1563 GST_CLOCK_SLAVE_UNLOCK (clock);
1566 g_value_set_uint64 (value, gst_clock_get_timeout (clock));
1569 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1576 * gst_clock_wait_for_sync:
1577 * @clock: a GstClock
1578 * @timeout: timeout for waiting or %GST_CLOCK_TIME_NONE
1580 * Waits until @clock is synced for reporting the current time. If @timeout
1581 * is %GST_CLOCK_TIME_NONE it will wait forever, otherwise it will time out
1582 * after @timeout nanoseconds.
1584 * For asynchronous waiting, the GstClock::synced signal can be used.
1586 * This returns immediately with TRUE if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1587 * is not set on the clock, or if the clock is already synced.
1589 * Returns: %TRUE if waiting was successful, or %FALSE on timeout
1594 gst_clock_wait_for_sync (GstClock * clock, GstClockTime timeout)
1596 gboolean timed_out = FALSE;
1598 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1600 GST_OBJECT_LOCK (clock);
1601 if (!GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1602 || clock->priv->synced) {
1603 GST_OBJECT_UNLOCK (clock);
1607 if (timeout != GST_CLOCK_TIME_NONE) {
1608 gint64 end_time = g_get_monotonic_time () + gst_util_uint64_scale (timeout,
1609 G_TIME_SPAN_SECOND, GST_SECOND);
1611 while (!clock->priv->synced && !timed_out) {
1613 !g_cond_wait_until (&clock->priv->sync_cond,
1614 GST_OBJECT_GET_LOCK (clock), end_time);
1618 while (!clock->priv->synced) {
1619 g_cond_wait (&clock->priv->sync_cond, GST_OBJECT_GET_LOCK (clock));
1622 GST_OBJECT_UNLOCK (clock);
1628 * gst_clock_is_synced:
1629 * @clock: a GstClock
1631 * Checks if the clock is currently synced.
1633 * This returns if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC is not set on the clock.
1635 * Returns: %TRUE if the clock is currently synced
1640 gst_clock_is_synced (GstClock * clock)
1642 g_return_val_if_fail (GST_IS_CLOCK (clock), TRUE);
1644 return !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1645 || clock->priv->synced;
1649 * gst_clock_set_synced:
1650 * @clock: a GstClock
1651 * @synced: if the clock is synced
1653 * Sets @clock to synced and emits the GstClock::synced signal, and wakes up any
1654 * thread waiting in gst_clock_wait_for_sync().
1656 * This function must only be called if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1657 * is set on the clock, and is intended to be called by subclasses only.
1662 gst_clock_set_synced (GstClock * clock, gboolean synced)
1664 g_return_if_fail (GST_IS_CLOCK (clock));
1665 g_return_if_fail (GST_OBJECT_FLAG_IS_SET (clock,
1666 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC));
1668 GST_OBJECT_LOCK (clock);
1669 if (clock->priv->synced != ! !synced) {
1670 clock->priv->synced = ! !synced;
1671 g_cond_signal (&clock->priv->sync_cond);
1672 GST_OBJECT_UNLOCK (clock);
1673 g_signal_emit (clock, gst_clock_signals[SIGNAL_SYNCED], 0, ! !synced);
1675 GST_OBJECT_UNLOCK (clock);