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.
26 * @short_description: Abstract class for global clocks
27 * @see_also: #GstSystemClock, #GstPipeline
29 * GStreamer uses a global clock to synchronize the plugins in a pipeline.
30 * Different clock implementations are possible by implementing this abstract
31 * base class or, more conveniently, by subclassing #GstSystemClock.
33 * The #GstClock returns a monotonically increasing time with the method
34 * gst_clock_get_time(). Its accuracy and base time depend on the specific
35 * clock implementation but time is always expressed in nanoseconds. Since the
36 * baseline of the clock is undefined, the clock time returned is not
37 * meaningful in itself, what matters are the deltas between two clock times.
38 * The time returned by a clock is called the absolute time.
40 * The pipeline uses the clock to calculate the running time. Usually all
41 * renderers synchronize to the global clock using the buffer timestamps, the
42 * newsegment events and the element's base time, see #GstPipeline.
44 * A clock implementation can support periodic and single shot clock
45 * notifications both synchronous and asynchronous.
47 * One first needs to create a #GstClockID for the periodic or single shot
48 * notification using gst_clock_new_single_shot_id() or
49 * gst_clock_new_periodic_id().
51 * To perform a blocking wait for the specific time of the #GstClockID use the
52 * gst_clock_id_wait(). To receive a callback when the specific time is reached
53 * in the clock use gst_clock_id_wait_async(). Both these calls can be
54 * interrupted with the gst_clock_id_unschedule() call. If the blocking wait is
55 * unscheduled a return value of #GST_CLOCK_UNSCHEDULED is returned.
57 * Periodic callbacks scheduled async will be repeatedly called automatically
58 * until it is unscheduled. To schedule a sync periodic callback,
59 * gst_clock_id_wait() should be called repeatedly.
61 * The async callbacks can happen from any thread, either provided by the core
62 * or from a streaming thread. The application should be prepared for this.
64 * A #GstClockID that has been unscheduled cannot be used again for any wait
65 * operation, a new #GstClockID should be created and the old unscheduled one
66 * should be destroyed with gst_clock_id_unref().
68 * It is possible to perform a blocking wait on the same #GstClockID from
69 * multiple threads. However, registering the same #GstClockID for multiple
70 * async notifications is not possible, the callback will only be called for
71 * the thread registering the entry last.
73 * None of the wait operations unref the #GstClockID, the owner is responsible
74 * for unreffing the ids itself. This holds for both periodic and single shot
75 * notifications. The reason being that the owner of the #GstClockID has to
76 * keep a handle to the #GstClockID to unblock the wait on FLUSHING events or
77 * state changes and if the entry would be unreffed automatically, the handle
78 * might become invalid without any notification.
80 * These clock operations do not operate on the running time, so the callbacks
81 * will also occur when not in PLAYING state as if the clock just keeps on
82 * running. Some clocks however do not progress when the element that provided
83 * the clock is not PLAYING.
85 * When a clock has the #GST_CLOCK_FLAG_CAN_SET_MASTER flag set, it can be
86 * slaved to another #GstClock with the gst_clock_set_master(). The clock will
87 * then automatically be synchronized to this master clock by repeatedly
88 * sampling the master clock and the slave clock and recalibrating the slave
89 * clock with gst_clock_set_calibration(). This feature is mostly useful for
90 * plugins that have an internal clock but must operate with another clock
91 * selected by the #GstPipeline. They can track the offset and rate difference
92 * of their internal clock relative to the master clock by using the
93 * gst_clock_get_calibration() function.
95 * The master/slave synchronisation can be tuned with the #GstClock:timeout,
96 * #GstClock:window-size and #GstClock:window-threshold properties.
97 * The #GstClock:timeout property defines the interval to sample the master
98 * clock and run the calibration functions. #GstClock:window-size defines the
99 * number of samples to use when calibrating and #GstClock:window-threshold
100 * defines the minimum number of samples before the calibration is performed.
103 #include "gst_private.h"
106 #include "gstclock.h"
108 #include "gstutils.h"
109 #include "glib-compat-private.h"
111 /* #define DEBUGGING_ENABLED */
113 #define DEFAULT_WINDOW_SIZE 32
114 #define DEFAULT_WINDOW_THRESHOLD 4
115 #define DEFAULT_TIMEOUT GST_SECOND / 10
121 PROP_WINDOW_THRESHOLD,
131 #define GST_CLOCK_SLAVE_LOCK(clock) g_mutex_lock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
132 #define GST_CLOCK_SLAVE_UNLOCK(clock) g_mutex_unlock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
134 struct _GstClockPrivate
136 GMutex slave_lock; /* order: SLAVE_LOCK, OBJECT_LOCK */
141 GstClockTime internal_calibration;
142 GstClockTime external_calibration;
143 GstClockTime rate_numerator;
144 GstClockTime rate_denominator;
145 GstClockTime last_time;
148 GstClockTime resolution;
150 /* for master/slave clocks */
153 /* with SLAVE_LOCK */
156 gint window_threshold;
158 GstClockTime timeout;
169 #define read_seqbegin(clock) \
170 g_atomic_int_get (&clock->priv->post_count);
172 static inline gboolean
173 read_seqretry (GstClock * clock, gint seq)
175 /* no retry if the seqnum did not change */
176 if (G_LIKELY (seq == g_atomic_int_get (&clock->priv->pre_count)))
179 /* wait for the writer to finish and retry */
180 GST_OBJECT_LOCK (clock);
181 GST_OBJECT_UNLOCK (clock);
185 #define write_seqlock(clock) \
187 GST_OBJECT_LOCK (clock); \
188 g_atomic_int_inc (&clock->priv->pre_count); \
191 #define write_sequnlock(clock) \
193 g_atomic_int_inc (&clock->priv->post_count); \
194 GST_OBJECT_UNLOCK (clock); \
197 #ifndef GST_DISABLE_GST_DEBUG
199 gst_clock_return_get_name (GstClockReturn ret)
204 case GST_CLOCK_EARLY:
206 case GST_CLOCK_UNSCHEDULED:
207 return "unscheduled";
210 case GST_CLOCK_BADTIME:
212 case GST_CLOCK_ERROR:
214 case GST_CLOCK_UNSUPPORTED:
215 return "unsupported";
224 #endif /* GST_DISABLE_GST_DEBUG */
226 static void gst_clock_dispose (GObject * object);
227 static void gst_clock_finalize (GObject * object);
229 static void gst_clock_set_property (GObject * object, guint prop_id,
230 const GValue * value, GParamSpec * pspec);
231 static void gst_clock_get_property (GObject * object, guint prop_id,
232 GValue * value, GParamSpec * pspec);
234 static guint gst_clock_signals[SIGNAL_LAST] = { 0 };
237 gst_clock_entry_new (GstClock * clock, GstClockTime time,
238 GstClockTime interval, GstClockEntryType type)
240 GstClockEntry *entry;
242 entry = g_slice_new (GstClockEntry);
244 /* FIXME: add tracer hook for struct allocations such as clock entries */
246 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
247 "created entry %p, time %" GST_TIME_FORMAT, entry, GST_TIME_ARGS (time));
250 entry->clock = clock;
253 entry->interval = interval;
254 entry->status = GST_CLOCK_OK;
256 entry->user_data = NULL;
257 entry->destroy_data = NULL;
258 entry->unscheduled = FALSE;
259 entry->woken_up = FALSE;
261 return (GstClockID) entry;
264 /* WARNING : Does not modify the refcount
265 * WARNING : Do not use if a pending clock operation is happening on that entry */
267 gst_clock_entry_reinit (GstClock * clock, GstClockEntry * entry,
268 GstClockTime time, GstClockTime interval, GstClockEntryType type)
270 g_return_val_if_fail (entry->status != GST_CLOCK_BUSY, FALSE);
271 g_return_val_if_fail (entry->clock == clock, FALSE);
275 entry->interval = interval;
276 entry->status = GST_CLOCK_OK;
277 entry->unscheduled = FALSE;
278 entry->woken_up = FALSE;
284 * gst_clock_single_shot_id_reinit:
285 * @clock: a #GstClock
287 * @time: The requested time.
289 * Reinitializes the provided single shot @id to the provided time. Does not
290 * modify the reference count.
292 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
293 * @time, else %FALSE.
296 gst_clock_single_shot_id_reinit (GstClock * clock, GstClockID id,
299 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, time,
300 GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
304 * gst_clock_periodic_id_reinit:
305 * @clock: a #GstClock
307 * @start_time: the requested start time
308 * @interval: the requested interval
310 * Reinitializes the provided periodic @id to the provided start time and
311 * interval. Does not modify the reference count.
313 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
314 * @time, else %FALSE.
317 gst_clock_periodic_id_reinit (GstClock * clock, GstClockID id,
318 GstClockTime start_time, GstClockTime interval)
320 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, start_time,
321 interval, GST_CLOCK_ENTRY_PERIODIC);
326 * @id: The #GstClockID to ref
328 * Increase the refcount of given @id.
330 * Returns: (transfer full): The same #GstClockID with increased refcount.
335 gst_clock_id_ref (GstClockID id)
337 g_return_val_if_fail (id != NULL, NULL);
339 g_atomic_int_inc (&((GstClockEntry *) id)->refcount);
345 _gst_clock_id_free (GstClockID id)
347 GstClockEntry *entry;
348 g_return_if_fail (id != NULL);
350 GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);
351 entry = (GstClockEntry *) id;
352 if (entry->destroy_data)
353 entry->destroy_data (entry->user_data);
355 /* FIXME: add tracer hook for struct allocations such as clock entries */
357 g_slice_free (GstClockEntry, id);
361 * gst_clock_id_unref:
362 * @id: (transfer full): The #GstClockID to unref
364 * Unref given @id. When the refcount reaches 0 the
365 * #GstClockID will be freed.
370 gst_clock_id_unref (GstClockID id)
374 g_return_if_fail (id != NULL);
376 zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);
377 /* if we ended up with the refcount at zero, free the id */
379 _gst_clock_id_free (id);
384 * gst_clock_new_single_shot_id:
385 * @clock: The #GstClockID to get a single shot notification from
386 * @time: the requested time
388 * Get a #GstClockID from @clock to trigger a single shot
389 * notification at the requested time. The single shot id should be
390 * unreffed after usage.
392 * Free-function: gst_clock_id_unref
394 * Returns: (transfer full): a #GstClockID that can be used to request the
400 gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)
402 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
404 return gst_clock_entry_new (clock,
405 time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
409 * gst_clock_new_periodic_id:
410 * @clock: The #GstClockID to get a periodic notification id from
411 * @start_time: the requested start time
412 * @interval: the requested interval
414 * Get an ID from @clock to trigger a periodic notification.
415 * The periodic notifications will start at time @start_time and
416 * will then be fired with the given @interval. @id should be unreffed
419 * Free-function: gst_clock_id_unref
421 * Returns: (transfer full): a #GstClockID that can be used to request the
427 gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,
428 GstClockTime interval)
430 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
431 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);
432 g_return_val_if_fail (interval != 0, NULL);
433 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);
435 return gst_clock_entry_new (clock,
436 start_time, interval, GST_CLOCK_ENTRY_PERIODIC);
440 * gst_clock_id_compare_func:
441 * @id1: A #GstClockID
442 * @id2: A #GstClockID to compare with
444 * Compares the two #GstClockID instances. This function can be used
445 * as a GCompareFunc when sorting ids.
447 * Returns: negative value if a < b; zero if a = b; positive value if a > b
452 gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)
454 GstClockEntry *entry1, *entry2;
456 entry1 = (GstClockEntry *) id1;
457 entry2 = (GstClockEntry *) id2;
459 if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {
462 if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {
469 * gst_clock_id_get_time:
470 * @id: The #GstClockID to query
472 * Get the time of the clock ID
474 * Returns: the time of the given clock id.
479 gst_clock_id_get_time (GstClockID id)
481 g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
483 return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);
488 * @id: The #GstClockID to wait on
489 * @jitter: (out) (allow-none): a pointer that will contain the jitter,
492 * Perform a blocking wait on @id.
493 * @id should have been created with gst_clock_new_single_shot_id()
494 * or gst_clock_new_periodic_id() and should not have been unscheduled
495 * with a call to gst_clock_id_unschedule().
497 * If the @jitter argument is not %NULL and this function returns #GST_CLOCK_OK
498 * or #GST_CLOCK_EARLY, it will contain the difference
499 * against the clock and the time of @id when this method was
501 * Positive values indicate how late @id was relative to the clock
502 * (in which case this function will return #GST_CLOCK_EARLY).
503 * Negative values indicate how much time was spent waiting on the clock
504 * before this function returned.
506 * Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned
507 * if the current clock time is past the time of @id, #GST_CLOCK_OK if
508 * @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was
509 * unscheduled with gst_clock_id_unschedule().
514 gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)
516 GstClockEntry *entry;
519 GstClockTime requested;
520 GstClockClass *cclass;
522 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
524 entry = (GstClockEntry *) id;
525 requested = GST_CLOCK_ENTRY_TIME (entry);
527 clock = GST_CLOCK_ENTRY_CLOCK (entry);
529 /* can't sync on invalid times */
530 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
533 cclass = GST_CLOCK_GET_CLASS (clock);
535 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);
537 /* if we have a wait_jitter function, use that */
538 if (G_UNLIKELY (cclass->wait == NULL))
541 res = cclass->wait (clock, entry, jitter);
543 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
544 "done waiting entry %p, res: %d (%s)", id, res,
545 gst_clock_return_get_name (res));
547 if (entry->type == GST_CLOCK_ENTRY_PERIODIC)
548 entry->time = requested + entry->interval;
555 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
556 "invalid time requested, returning _BADTIME");
557 return GST_CLOCK_BADTIME;
561 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
562 return GST_CLOCK_UNSUPPORTED;
567 * gst_clock_id_wait_async:
568 * @id: a #GstClockID to wait on
569 * @func: The callback function
570 * @user_data: User data passed in the callback
571 * @destroy_data: #GDestroyNotify for user_data
573 * Register a callback on the given #GstClockID @id with the given
574 * function and user_data. When passing a #GstClockID with an invalid
575 * time to this function, the callback will be called immediately
576 * with a time set to GST_CLOCK_TIME_NONE. The callback will
577 * be called when the time of @id has been reached.
579 * The callback @func can be invoked from any thread, either provided by the
580 * core or from a streaming thread. The application should be prepared for this.
582 * Returns: the result of the non blocking wait.
587 gst_clock_id_wait_async (GstClockID id,
588 GstClockCallback func, gpointer user_data, GDestroyNotify destroy_data)
590 GstClockEntry *entry;
593 GstClockClass *cclass;
594 GstClockTime requested;
596 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
597 g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
599 entry = (GstClockEntry *) id;
600 requested = GST_CLOCK_ENTRY_TIME (entry);
601 clock = GST_CLOCK_ENTRY_CLOCK (entry);
603 /* can't sync on invalid times */
604 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
607 cclass = GST_CLOCK_GET_CLASS (clock);
609 if (G_UNLIKELY (cclass->wait_async == NULL))
613 entry->user_data = user_data;
614 entry->destroy_data = destroy_data;
616 res = cclass->wait_async (clock, entry);
623 (func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
624 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
625 "invalid time requested, returning _BADTIME");
626 return GST_CLOCK_BADTIME;
630 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
631 return GST_CLOCK_UNSUPPORTED;
636 * gst_clock_id_unschedule:
637 * @id: The id to unschedule
639 * Cancel an outstanding request with @id. This can either
640 * be an outstanding async notification or a pending sync notification.
641 * After this call, @id cannot be used anymore to receive sync or
642 * async notifications, you need to create a new #GstClockID.
647 gst_clock_id_unschedule (GstClockID id)
649 GstClockEntry *entry;
651 GstClockClass *cclass;
653 g_return_if_fail (id != NULL);
655 entry = (GstClockEntry *) id;
656 clock = entry->clock;
658 cclass = GST_CLOCK_GET_CLASS (clock);
660 if (G_LIKELY (cclass->unschedule))
661 cclass->unschedule (clock, entry);
666 * GstClock abstract base class implementation
668 #define gst_clock_parent_class parent_class
669 G_DEFINE_ABSTRACT_TYPE (GstClock, gst_clock, GST_TYPE_OBJECT);
672 gst_clock_class_init (GstClockClass * klass)
674 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
676 gobject_class->dispose = gst_clock_dispose;
677 gobject_class->finalize = gst_clock_finalize;
678 gobject_class->set_property = gst_clock_set_property;
679 gobject_class->get_property = gst_clock_get_property;
681 g_object_class_install_property (gobject_class, PROP_WINDOW_SIZE,
682 g_param_spec_int ("window-size", "Window size",
683 "The size of the window used to calculate rate and offset", 2, 1024,
684 DEFAULT_WINDOW_SIZE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
685 g_object_class_install_property (gobject_class, PROP_WINDOW_THRESHOLD,
686 g_param_spec_int ("window-threshold", "Window threshold",
687 "The threshold to start calculating rate and offset", 2, 1024,
688 DEFAULT_WINDOW_THRESHOLD,
689 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
690 g_object_class_install_property (gobject_class, PROP_TIMEOUT,
691 g_param_spec_uint64 ("timeout", "Timeout",
692 "The amount of time, in nanoseconds, to sample master and slave clocks",
693 0, G_MAXUINT64, DEFAULT_TIMEOUT,
694 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
699 * @synced: if the clock is synced now
701 * Signaled on clocks with GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC set once
702 * the clock is synchronized, or when it completely lost synchronization.
703 * This signal will not be emitted on clocks without the flag.
705 * This signal will be emitted from an arbitrary thread, most likely not
706 * the application's main thread.
710 gst_clock_signals[SIGNAL_SYNCED] =
711 g_signal_new ("synced", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
713 g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_BOOLEAN);
715 g_type_class_add_private (klass, sizeof (GstClockPrivate));
719 gst_clock_init (GstClock * clock)
721 GstClockPrivate *priv;
724 G_TYPE_INSTANCE_GET_PRIVATE (clock, GST_TYPE_CLOCK, GstClockPrivate);
728 priv->internal_calibration = 0;
729 priv->external_calibration = 0;
730 priv->rate_numerator = 1;
731 priv->rate_denominator = 1;
733 g_mutex_init (&priv->slave_lock);
734 g_cond_init (&priv->sync_cond);
735 priv->window_size = DEFAULT_WINDOW_SIZE;
736 priv->window_threshold = DEFAULT_WINDOW_THRESHOLD;
737 priv->filling = TRUE;
738 priv->time_index = 0;
739 priv->timeout = DEFAULT_TIMEOUT;
740 priv->times = g_new0 (GstClockTime, 4 * priv->window_size);
742 /* clear floating flag */
743 gst_object_ref_sink (clock);
747 gst_clock_dispose (GObject * object)
749 GstClock *clock = GST_CLOCK (object);
752 GST_OBJECT_LOCK (clock);
753 master_p = &clock->priv->master;
754 gst_object_replace ((GstObject **) master_p, NULL);
755 GST_OBJECT_UNLOCK (clock);
757 G_OBJECT_CLASS (parent_class)->dispose (object);
761 gst_clock_finalize (GObject * object)
763 GstClock *clock = GST_CLOCK (object);
765 GST_CLOCK_SLAVE_LOCK (clock);
766 if (clock->priv->clockid) {
767 gst_clock_id_unschedule (clock->priv->clockid);
768 gst_clock_id_unref (clock->priv->clockid);
769 clock->priv->clockid = NULL;
771 g_free (clock->priv->times);
772 clock->priv->times = NULL;
773 GST_CLOCK_SLAVE_UNLOCK (clock);
775 g_mutex_clear (&clock->priv->slave_lock);
776 g_cond_clear (&clock->priv->sync_cond);
778 G_OBJECT_CLASS (parent_class)->finalize (object);
782 * gst_clock_set_resolution:
783 * @clock: a #GstClock
784 * @resolution: The resolution to set
786 * Set the accuracy of the clock. Some clocks have the possibility to operate
787 * with different accuracy at the expense of more resource usage. There is
788 * normally no need to change the default resolution of a clock. The resolution
789 * of a clock can only be changed if the clock has the
790 * #GST_CLOCK_FLAG_CAN_SET_RESOLUTION flag set.
792 * Returns: the new resolution of the clock.
795 gst_clock_set_resolution (GstClock * clock, GstClockTime resolution)
797 GstClockPrivate *priv;
798 GstClockClass *cclass;
800 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
801 g_return_val_if_fail (resolution != 0, 0);
803 cclass = GST_CLOCK_GET_CLASS (clock);
806 if (cclass->change_resolution)
808 cclass->change_resolution (clock, priv->resolution, resolution);
810 return priv->resolution;
814 * gst_clock_get_resolution:
815 * @clock: a #GstClock
817 * Get the accuracy of the clock. The accuracy of the clock is the granularity
818 * of the values returned by gst_clock_get_time().
820 * Returns: the resolution of the clock in units of #GstClockTime.
825 gst_clock_get_resolution (GstClock * clock)
827 GstClockClass *cclass;
829 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
831 cclass = GST_CLOCK_GET_CLASS (clock);
833 if (cclass->get_resolution)
834 return cclass->get_resolution (clock);
839 /* FIXME 2.0: Remove clock parameter below */
841 * gst_clock_adjust_with_calibration:
842 * @clock: (allow-none): a #GstClock to use
843 * @internal_target: a clock time
844 * @cinternal: a reference internal time
845 * @cexternal: a reference external time
846 * @cnum: the numerator of the rate of the clock relative to its
848 * @cdenom: the denominator of the rate of the clock
850 * Converts the given @internal_target clock time to the external time,
851 * using the passed calibration parameters. This function performs the
852 * same calculation as gst_clock_adjust_unlocked() when called using the
853 * current calibration parameters, but doesn't ensure a monotonically
854 * increasing result as gst_clock_adjust_unlocked() does.
856 * Note: The @clock parameter is unused and can be NULL
858 * Returns: the converted time of the clock.
863 gst_clock_adjust_with_calibration (GstClock * clock,
864 GstClockTime internal_target, GstClockTime cinternal,
865 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
869 /* avoid divide by 0 */
870 if (G_UNLIKELY (cdenom == 0))
873 /* The formula is (internal - cinternal) * cnum / cdenom + cexternal
875 * Since we do math on unsigned 64-bit ints we have to special case for
876 * internal < cinternal to get the sign right. this case is not very common,
879 if (G_LIKELY (internal_target >= cinternal)) {
880 ret = internal_target - cinternal;
881 ret = gst_util_uint64_scale (ret, cnum, cdenom);
884 ret = cinternal - internal_target;
885 ret = gst_util_uint64_scale (ret, cnum, cdenom);
887 if (G_LIKELY (cexternal > ret))
888 ret = cexternal - ret;
897 * gst_clock_adjust_unlocked:
898 * @clock: a #GstClock to use
899 * @internal: a clock time
901 * Converts the given @internal clock time to the external time, adjusting for the
902 * rate and reference time set with gst_clock_set_calibration() and making sure
903 * that the returned time is increasing. This function should be called with the
904 * clock's OBJECT_LOCK held and is mainly used by clock subclasses.
906 * This function is the reverse of gst_clock_unadjust_unlocked().
908 * Returns: the converted time of the clock.
911 gst_clock_adjust_unlocked (GstClock * clock, GstClockTime internal)
913 GstClockTime ret, cinternal, cexternal, cnum, cdenom;
914 GstClockPrivate *priv = clock->priv;
916 /* get calibration values for readability */
917 cinternal = priv->internal_calibration;
918 cexternal = priv->external_calibration;
919 cnum = priv->rate_numerator;
920 cdenom = priv->rate_denominator;
923 gst_clock_adjust_with_calibration (clock, internal, cinternal, cexternal,
926 /* make sure the time is increasing */
927 priv->last_time = MAX (ret, priv->last_time);
929 return priv->last_time;
932 /* FIXME 2.0: Remove clock parameter below */
934 * gst_clock_unadjust_with_calibration:
935 * @clock: (allow-none): a #GstClock to use
936 * @external_target: a clock time
937 * @cinternal: a reference internal time
938 * @cexternal: a reference external time
939 * @cnum: the numerator of the rate of the clock relative to its
941 * @cdenom: the denominator of the rate of the clock
943 * Converts the given @external_target clock time to the internal time,
944 * using the passed calibration parameters. This function performs the
945 * same calculation as gst_clock_unadjust_unlocked() when called using the
946 * current calibration parameters.
948 * Note: The @clock parameter is unused and can be NULL
950 * Returns: the converted time of the clock.
955 gst_clock_unadjust_with_calibration (GstClock * clock,
956 GstClockTime external_target, GstClockTime cinternal,
957 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
961 /* avoid divide by 0 */
962 if (G_UNLIKELY (cnum == 0))
965 /* The formula is (external - cexternal) * cdenom / cnum + cinternal */
966 if (G_LIKELY (external_target >= cexternal)) {
967 ret = external_target - cexternal;
968 ret = gst_util_uint64_scale (ret, cdenom, cnum);
971 ret = cexternal - external_target;
972 ret = gst_util_uint64_scale (ret, cdenom, cnum);
973 if (G_LIKELY (cinternal > ret))
974 ret = cinternal - ret;
983 * gst_clock_unadjust_unlocked:
984 * @clock: a #GstClock to use
985 * @external: an external clock time
987 * Converts the given @external clock time to the internal time of @clock,
988 * using the rate and reference time set with gst_clock_set_calibration().
989 * This function should be called with the clock's OBJECT_LOCK held and
990 * is mainly used by clock subclasses.
992 * This function is the reverse of gst_clock_adjust_unlocked().
994 * Returns: the internal time of the clock corresponding to @external.
997 gst_clock_unadjust_unlocked (GstClock * clock, GstClockTime external)
999 GstClockTime cinternal, cexternal, cnum, cdenom;
1000 GstClockPrivate *priv = clock->priv;
1002 /* get calibration values for readability */
1003 cinternal = priv->internal_calibration;
1004 cexternal = priv->external_calibration;
1005 cnum = priv->rate_numerator;
1006 cdenom = priv->rate_denominator;
1008 return gst_clock_unadjust_with_calibration (clock, external, cinternal,
1009 cexternal, cnum, cdenom);
1013 * gst_clock_get_internal_time:
1014 * @clock: a #GstClock to query
1016 * Gets the current internal time of the given clock. The time is returned
1017 * unadjusted for the offset and the rate.
1019 * Returns: the internal time of the clock. Or GST_CLOCK_TIME_NONE when
1020 * given invalid input.
1025 gst_clock_get_internal_time (GstClock * clock)
1028 GstClockClass *cclass;
1030 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1032 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (clock,
1033 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC) && !clock->priv->synced))
1034 GST_CAT_WARNING_OBJECT (GST_CAT_CLOCK, clock,
1035 "clock is not synchronized yet");
1037 cclass = GST_CLOCK_GET_CLASS (clock);
1039 if (G_UNLIKELY (cclass->get_internal_time == NULL))
1042 ret = cclass->get_internal_time (clock);
1044 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "internal time %" GST_TIME_FORMAT,
1045 GST_TIME_ARGS (ret));
1052 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1053 "internal time not supported, return 0");
1054 return G_GINT64_CONSTANT (0);
1059 * gst_clock_get_time:
1060 * @clock: a #GstClock to query
1062 * Gets the current time of the given clock. The time is always
1063 * monotonically increasing and adjusted according to the current
1066 * Returns: the time of the clock. Or GST_CLOCK_TIME_NONE when
1067 * given invalid input.
1072 gst_clock_get_time (GstClock * clock)
1077 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1080 /* reget the internal time when we retry to get the most current
1082 ret = gst_clock_get_internal_time (clock);
1084 seq = read_seqbegin (clock);
1085 /* this will scale for rate and offset */
1086 ret = gst_clock_adjust_unlocked (clock, ret);
1087 } while (read_seqretry (clock, seq));
1089 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "adjusted time %" GST_TIME_FORMAT,
1090 GST_TIME_ARGS (ret));
1096 * gst_clock_set_calibration:
1097 * @clock: a #GstClock to calibrate
1098 * @internal: a reference internal time
1099 * @external: a reference external time
1100 * @rate_num: the numerator of the rate of the clock relative to its
1102 * @rate_denom: the denominator of the rate of the clock
1104 * Adjusts the rate and time of @clock. A rate of 1/1 is the normal speed of
1105 * the clock. Values bigger than 1/1 make the clock go faster.
1107 * @internal and @external are calibration parameters that arrange that
1108 * gst_clock_get_time() should have been @external at internal time @internal.
1109 * This internal time should not be in the future; that is, it should be less
1110 * than the value of gst_clock_get_internal_time() when this function is called.
1112 * Subsequent calls to gst_clock_get_time() will return clock times computed as
1116 * time = (internal_time - internal) * rate_num / rate_denom + external
1119 * This formula is implemented in gst_clock_adjust_unlocked(). Of course, it
1120 * tries to do the integer arithmetic as precisely as possible.
1122 * Note that gst_clock_get_time() always returns increasing values so when you
1123 * move the clock backwards, gst_clock_get_time() will report the previous value
1124 * until the clock catches up.
1129 gst_clock_set_calibration (GstClock * clock, GstClockTime internal, GstClockTime
1130 external, GstClockTime rate_num, GstClockTime rate_denom)
1132 GstClockPrivate *priv;
1134 g_return_if_fail (GST_IS_CLOCK (clock));
1135 g_return_if_fail (rate_num != GST_CLOCK_TIME_NONE);
1136 g_return_if_fail (rate_denom > 0 && rate_denom != GST_CLOCK_TIME_NONE);
1140 write_seqlock (clock);
1141 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1142 "internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT " %"
1143 G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT " = %f", GST_TIME_ARGS (internal),
1144 GST_TIME_ARGS (external), rate_num, rate_denom,
1145 gst_guint64_to_gdouble (rate_num) / gst_guint64_to_gdouble (rate_denom));
1147 priv->internal_calibration = internal;
1148 priv->external_calibration = external;
1149 priv->rate_numerator = rate_num;
1150 priv->rate_denominator = rate_denom;
1151 write_sequnlock (clock);
1155 * gst_clock_get_calibration:
1156 * @clock: a #GstClock
1157 * @internal: (out) (allow-none): a location to store the internal time
1158 * @external: (out) (allow-none): a location to store the external time
1159 * @rate_num: (out) (allow-none): a location to store the rate numerator
1160 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1162 * Gets the internal rate and reference time of @clock. See
1163 * gst_clock_set_calibration() for more information.
1165 * @internal, @external, @rate_num, and @rate_denom can be left %NULL if the
1166 * caller is not interested in the values.
1171 gst_clock_get_calibration (GstClock * clock, GstClockTime * internal,
1172 GstClockTime * external, GstClockTime * rate_num, GstClockTime * rate_denom)
1175 GstClockPrivate *priv;
1177 g_return_if_fail (GST_IS_CLOCK (clock));
1182 seq = read_seqbegin (clock);
1184 *rate_num = priv->rate_numerator;
1186 *rate_denom = priv->rate_denominator;
1188 *external = priv->external_calibration;
1190 *internal = priv->internal_calibration;
1191 } while (read_seqretry (clock, seq));
1194 /* will be called repeatedly to sample the master and slave clock
1195 * to recalibrate the clock */
1197 gst_clock_slave_callback (GstClock * master, GstClockTime time,
1198 GstClockID id, GstClock * clock)
1200 GstClockTime stime, mtime;
1203 if (!gst_clock_is_synced (clock)) {
1204 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1205 "Slave clock is not synced yet");
1209 stime = gst_clock_get_internal_time (clock);
1210 mtime = gst_clock_get_time (master);
1212 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1213 "master %" GST_TIME_FORMAT ", slave %" GST_TIME_FORMAT,
1214 GST_TIME_ARGS (mtime), GST_TIME_ARGS (stime));
1216 gst_clock_add_observation (clock, stime, mtime, &r_squared);
1218 /* FIXME, we can use the r_squared value to adjust the timeout
1219 * value of the clockid */
1225 * gst_clock_set_master:
1226 * @clock: a #GstClock
1227 * @master: (allow-none): a master #GstClock
1229 * Set @master as the master clock for @clock. @clock will be automatically
1230 * calibrated so that gst_clock_get_time() reports the same time as the
1233 * A clock provider that slaves its clock to a master can get the current
1234 * calibration values with gst_clock_get_calibration().
1236 * @master can be %NULL in which case @clock will not be slaved anymore. It will
1237 * however keep reporting its time adjusted with the last configured rate
1240 * Returns: %TRUE if the clock is capable of being slaved to a master clock.
1241 * Trying to set a master on a clock without the
1242 * #GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return %FALSE.
1247 gst_clock_set_master (GstClock * clock, GstClock * master)
1249 GstClock **master_p;
1250 GstClockPrivate *priv;
1252 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1253 g_return_val_if_fail (master != clock, FALSE);
1255 GST_OBJECT_LOCK (clock);
1256 /* we always allow setting the master to NULL */
1257 if (master && !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER))
1259 if (master && !gst_clock_is_synced (master))
1260 goto master_not_synced;
1262 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1263 "slaving %p to master clock %p", clock, master);
1264 GST_OBJECT_UNLOCK (clock);
1268 GST_CLOCK_SLAVE_LOCK (clock);
1269 if (priv->clockid) {
1270 gst_clock_id_unschedule (priv->clockid);
1271 gst_clock_id_unref (priv->clockid);
1272 priv->clockid = NULL;
1275 priv->filling = TRUE;
1276 priv->time_index = 0;
1277 /* use the master periodic id to schedule sampling and
1278 * clock calibration. */
1279 priv->clockid = gst_clock_new_periodic_id (master,
1280 gst_clock_get_time (master), priv->timeout);
1281 gst_clock_id_wait_async (priv->clockid,
1282 (GstClockCallback) gst_clock_slave_callback,
1283 gst_object_ref (clock), (GDestroyNotify) gst_object_unref);
1285 GST_CLOCK_SLAVE_UNLOCK (clock);
1287 GST_OBJECT_LOCK (clock);
1288 master_p = &priv->master;
1289 gst_object_replace ((GstObject **) master_p, (GstObject *) master);
1290 GST_OBJECT_UNLOCK (clock);
1297 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1298 "cannot be slaved to a master clock");
1299 GST_OBJECT_UNLOCK (clock);
1305 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, master,
1306 "master clock is not synced yet");
1307 GST_OBJECT_UNLOCK (clock);
1313 * gst_clock_get_master:
1314 * @clock: a #GstClock
1316 * Get the master clock that @clock is slaved to or %NULL when the clock is
1317 * not slaved to any master clock.
1319 * Returns: (transfer full) (nullable): a master #GstClock or %NULL
1320 * when this clock is not slaved to a master clock. Unref after
1326 gst_clock_get_master (GstClock * clock)
1328 GstClock *result = NULL;
1329 GstClockPrivate *priv;
1331 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
1335 GST_OBJECT_LOCK (clock);
1337 result = gst_object_ref (priv->master);
1338 GST_OBJECT_UNLOCK (clock);
1344 * gst_clock_add_observation:
1345 * @clock: a #GstClock
1346 * @slave: a time on the slave
1347 * @master: a time on the master
1348 * @r_squared: (out): a pointer to hold the result
1350 * The time @master of the master clock and the time @slave of the slave
1351 * clock are added to the list of observations. If enough observations
1352 * are available, a linear regression algorithm is run on the
1353 * observations and @clock is recalibrated.
1355 * If this functions returns %TRUE, @r_squared will contain the
1356 * correlation coefficient of the interpolation. A value of 1.0
1357 * means a perfect regression was performed. This value can
1358 * be used to control the sampling frequency of the master and slave
1361 * Returns: %TRUE if enough observations were added to run the
1362 * regression algorithm.
1367 gst_clock_add_observation (GstClock * clock, GstClockTime slave,
1368 GstClockTime master, gdouble * r_squared)
1370 GstClockTime m_num, m_denom, b, xbase;
1372 if (!gst_clock_add_observation_unapplied (clock, slave, master, r_squared,
1373 &xbase, &b, &m_num, &m_denom))
1376 /* if we have a valid regression, adjust the clock */
1377 gst_clock_set_calibration (clock, xbase, b, m_num, m_denom);
1383 * gst_clock_add_observation_unapplied:
1384 * @clock: a #GstClock
1385 * @slave: a time on the slave
1386 * @master: a time on the master
1387 * @r_squared: (out): a pointer to hold the result
1388 * @internal: (out) (allow-none): a location to store the internal time
1389 * @external: (out) (allow-none): a location to store the external time
1390 * @rate_num: (out) (allow-none): a location to store the rate numerator
1391 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1393 * Add a clock observation to the internal slaving algorithm the same as
1394 * gst_clock_add_observation(), and return the result of the master clock
1395 * estimation, without updating the internal calibration.
1397 * The caller can then take the results and call gst_clock_set_calibration()
1398 * with the values, or some modified version of them.
1403 gst_clock_add_observation_unapplied (GstClock * clock, GstClockTime slave,
1404 GstClockTime master, gdouble * r_squared,
1405 GstClockTime * internal, GstClockTime * external,
1406 GstClockTime * rate_num, GstClockTime * rate_denom)
1408 GstClockTime m_num, m_denom, b, xbase;
1409 GstClockPrivate *priv;
1412 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1413 g_return_val_if_fail (r_squared != NULL, FALSE);
1417 GST_CLOCK_SLAVE_LOCK (clock);
1419 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1420 "adding observation slave %" GST_TIME_FORMAT ", master %" GST_TIME_FORMAT,
1421 GST_TIME_ARGS (slave), GST_TIME_ARGS (master));
1423 priv->times[(4 * priv->time_index)] = slave;
1424 priv->times[(4 * priv->time_index) + 2] = master;
1427 if (G_UNLIKELY (priv->time_index == priv->window_size)) {
1428 priv->filling = FALSE;
1429 priv->time_index = 0;
1432 if (G_UNLIKELY (priv->filling && priv->time_index < priv->window_threshold))
1435 n = priv->filling ? priv->time_index : priv->window_size;
1436 if (!_priv_gst_do_linear_regression (priv->times, n, &m_num, &m_denom, &b,
1440 GST_CLOCK_SLAVE_UNLOCK (clock);
1442 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1443 "adjusting clock to m=%" G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT ", b=%"
1444 G_GUINT64_FORMAT " (rsquared=%g)", m_num, m_denom, b, *r_squared);
1453 *rate_denom = m_denom;
1459 GST_CLOCK_SLAVE_UNLOCK (clock);
1464 /* no valid regression has been done, ignore the result then */
1465 GST_CLOCK_SLAVE_UNLOCK (clock);
1471 * gst_clock_set_timeout:
1472 * @clock: a #GstClock
1473 * @timeout: a timeout
1475 * Set the amount of time, in nanoseconds, to sample master and slave
1479 gst_clock_set_timeout (GstClock * clock, GstClockTime timeout)
1481 g_return_if_fail (GST_IS_CLOCK (clock));
1483 GST_CLOCK_SLAVE_LOCK (clock);
1484 clock->priv->timeout = timeout;
1485 GST_CLOCK_SLAVE_UNLOCK (clock);
1489 * gst_clock_get_timeout:
1490 * @clock: a #GstClock
1492 * Get the amount of time that master and slave clocks are sampled.
1494 * Returns: the interval between samples.
1497 gst_clock_get_timeout (GstClock * clock)
1499 GstClockTime result;
1501 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1503 GST_CLOCK_SLAVE_LOCK (clock);
1504 result = clock->priv->timeout;
1505 GST_CLOCK_SLAVE_UNLOCK (clock);
1511 gst_clock_set_property (GObject * object, guint prop_id,
1512 const GValue * value, GParamSpec * pspec)
1515 GstClockPrivate *priv;
1517 clock = GST_CLOCK (object);
1521 case PROP_WINDOW_SIZE:
1522 GST_CLOCK_SLAVE_LOCK (clock);
1523 priv->window_size = g_value_get_int (value);
1524 priv->window_threshold = MIN (priv->window_threshold, priv->window_size);
1525 priv->times = g_renew (GstClockTime, priv->times, 4 * priv->window_size);
1526 /* restart calibration */
1527 priv->filling = TRUE;
1528 priv->time_index = 0;
1529 GST_CLOCK_SLAVE_UNLOCK (clock);
1531 case PROP_WINDOW_THRESHOLD:
1532 GST_CLOCK_SLAVE_LOCK (clock);
1533 priv->window_threshold = MIN (g_value_get_int (value), priv->window_size);
1534 GST_CLOCK_SLAVE_UNLOCK (clock);
1537 gst_clock_set_timeout (clock, g_value_get_uint64 (value));
1540 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1546 gst_clock_get_property (GObject * object, guint prop_id,
1547 GValue * value, GParamSpec * pspec)
1550 GstClockPrivate *priv;
1552 clock = GST_CLOCK (object);
1556 case PROP_WINDOW_SIZE:
1557 GST_CLOCK_SLAVE_LOCK (clock);
1558 g_value_set_int (value, priv->window_size);
1559 GST_CLOCK_SLAVE_UNLOCK (clock);
1561 case PROP_WINDOW_THRESHOLD:
1562 GST_CLOCK_SLAVE_LOCK (clock);
1563 g_value_set_int (value, priv->window_threshold);
1564 GST_CLOCK_SLAVE_UNLOCK (clock);
1567 g_value_set_uint64 (value, gst_clock_get_timeout (clock));
1570 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1577 * gst_clock_wait_for_sync:
1578 * @clock: a GstClock
1579 * @timeout: timeout for waiting or %GST_CLOCK_TIME_NONE
1581 * Waits until @clock is synced for reporting the current time. If @timeout
1582 * is %GST_CLOCK_TIME_NONE it will wait forever, otherwise it will time out
1583 * after @timeout nanoseconds.
1585 * For asynchronous waiting, the GstClock::synced signal can be used.
1588 * This returns immediately with TRUE if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1589 * is not set on the clock, or if the clock is already synced.
1591 * Returns: %TRUE if waiting was successful, or %FALSE on timeout
1596 gst_clock_wait_for_sync (GstClock * clock, GstClockTime timeout)
1598 gboolean timed_out = FALSE;
1600 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1602 GST_OBJECT_LOCK (clock);
1603 if (!GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1604 || clock->priv->synced) {
1605 GST_OBJECT_UNLOCK (clock);
1609 if (timeout != GST_CLOCK_TIME_NONE) {
1610 gint64 end_time = g_get_monotonic_time () + gst_util_uint64_scale (timeout,
1611 G_TIME_SPAN_SECOND, GST_SECOND);
1613 while (!clock->priv->synced && !timed_out) {
1615 !g_cond_wait_until (&clock->priv->sync_cond,
1616 GST_OBJECT_GET_LOCK (clock), end_time);
1620 while (!clock->priv->synced) {
1621 g_cond_wait (&clock->priv->sync_cond, GST_OBJECT_GET_LOCK (clock));
1624 GST_OBJECT_UNLOCK (clock);
1630 * gst_clock_is_synced:
1631 * @clock: a GstClock
1633 * Checks if the clock is currently synced.
1635 * This returns if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC is not set on the clock.
1637 * Returns: %TRUE if the clock is currently synced
1642 gst_clock_is_synced (GstClock * clock)
1644 g_return_val_if_fail (GST_IS_CLOCK (clock), TRUE);
1646 return !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1647 || clock->priv->synced;
1651 * gst_clock_set_synced:
1652 * @clock: a GstClock
1653 * @synced: if the clock is synced
1655 * Sets @clock to synced and emits the GstClock::synced signal, and wakes up any
1656 * thread waiting in gst_clock_wait_for_sync().
1658 * This function must only be called if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1659 * is set on the clock, and is intended to be called by subclasses only.
1664 gst_clock_set_synced (GstClock * clock, gboolean synced)
1666 g_return_if_fail (GST_IS_CLOCK (clock));
1667 g_return_if_fail (GST_OBJECT_FLAG_IS_SET (clock,
1668 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC));
1670 GST_OBJECT_LOCK (clock);
1671 if (clock->priv->synced != ! !synced) {
1672 clock->priv->synced = ! !synced;
1673 g_cond_signal (&clock->priv->sync_cond);
1674 GST_OBJECT_UNLOCK (clock);
1675 g_signal_emit (clock, gst_clock_signals[SIGNAL_SYNCED], 0, ! !synced);
1677 GST_OBJECT_UNLOCK (clock);