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 #ifndef GST_DISABLE_DEPRECATED
253 entry->clock = clock;
255 g_weak_ref_init (&entry->ABI.clock, clock);
258 entry->interval = interval;
259 entry->status = GST_CLOCK_OK;
261 entry->user_data = NULL;
262 entry->destroy_data = NULL;
263 entry->unscheduled = FALSE;
264 entry->woken_up = FALSE;
266 return (GstClockID) entry;
269 /* WARNING : Does not modify the refcount
270 * WARNING : Do not use if a pending clock operation is happening on that entry */
272 gst_clock_entry_reinit (GstClock * clock, GstClockEntry * entry,
273 GstClockTime time, GstClockTime interval, GstClockEntryType type)
275 g_return_val_if_fail (entry->status != GST_CLOCK_BUSY, FALSE);
276 g_return_val_if_fail (gst_clock_id_uses_clock ((GstClockID) entry, clock),
281 entry->interval = interval;
282 entry->status = GST_CLOCK_OK;
283 entry->unscheduled = FALSE;
284 entry->woken_up = FALSE;
290 * gst_clock_single_shot_id_reinit:
291 * @clock: a #GstClock
293 * @time: The requested time.
295 * Reinitializes the provided single shot @id to the provided time. Does not
296 * modify the reference count.
298 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
299 * @time, else %FALSE.
302 gst_clock_single_shot_id_reinit (GstClock * clock, GstClockID id,
305 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, time,
306 GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
310 * gst_clock_periodic_id_reinit:
311 * @clock: a #GstClock
313 * @start_time: the requested start time
314 * @interval: the requested interval
316 * Reinitializes the provided periodic @id to the provided start time and
317 * interval. Does not modify the reference count.
319 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
320 * @time, else %FALSE.
323 gst_clock_periodic_id_reinit (GstClock * clock, GstClockID id,
324 GstClockTime start_time, GstClockTime interval)
326 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, start_time,
327 interval, GST_CLOCK_ENTRY_PERIODIC);
332 * @id: The #GstClockID to ref
334 * Increase the refcount of given @id.
336 * Returns: (transfer full): The same #GstClockID with increased refcount.
341 gst_clock_id_ref (GstClockID id)
343 g_return_val_if_fail (id != NULL, NULL);
345 g_atomic_int_inc (&((GstClockEntry *) id)->refcount);
351 _gst_clock_id_free (GstClockID id)
353 GstClockEntry *entry;
354 g_return_if_fail (id != NULL);
356 GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);
357 entry = (GstClockEntry *) id;
358 if (entry->destroy_data)
359 entry->destroy_data (entry->user_data);
361 g_weak_ref_clear (&entry->ABI.clock);
363 /* FIXME: add tracer hook for struct allocations such as clock entries */
365 g_slice_free (GstClockEntry, id);
369 * gst_clock_id_unref:
370 * @id: (transfer full): The #GstClockID to unref
372 * Unref given @id. When the refcount reaches 0 the
373 * #GstClockID will be freed.
378 gst_clock_id_unref (GstClockID id)
382 g_return_if_fail (id != NULL);
384 zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);
385 /* if we ended up with the refcount at zero, free the id */
387 _gst_clock_id_free (id);
392 * gst_clock_new_single_shot_id:
393 * @clock: The #GstClockID to get a single shot notification from
394 * @time: the requested time
396 * Get a #GstClockID from @clock to trigger a single shot
397 * notification at the requested time. The single shot id should be
398 * unreffed after usage.
400 * Free-function: gst_clock_id_unref
402 * Returns: (transfer full): a #GstClockID that can be used to request the
408 gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)
410 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
412 return gst_clock_entry_new (clock,
413 time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
417 * gst_clock_new_periodic_id:
418 * @clock: The #GstClockID to get a periodic notification id from
419 * @start_time: the requested start time
420 * @interval: the requested interval
422 * Get an ID from @clock to trigger a periodic notification.
423 * The periodic notifications will start at time @start_time and
424 * will then be fired with the given @interval. @id should be unreffed
427 * Free-function: gst_clock_id_unref
429 * Returns: (transfer full): a #GstClockID that can be used to request the
435 gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,
436 GstClockTime interval)
438 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
439 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);
440 g_return_val_if_fail (interval != 0, NULL);
441 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);
443 return gst_clock_entry_new (clock,
444 start_time, interval, GST_CLOCK_ENTRY_PERIODIC);
448 * gst_clock_id_compare_func:
449 * @id1: A #GstClockID
450 * @id2: A #GstClockID to compare with
452 * Compares the two #GstClockID instances. This function can be used
453 * as a GCompareFunc when sorting ids.
455 * Returns: negative value if a < b; zero if a = b; positive value if a > b
460 gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)
462 GstClockEntry *entry1, *entry2;
464 entry1 = (GstClockEntry *) id1;
465 entry2 = (GstClockEntry *) id2;
467 if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {
470 if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {
477 * gst_clock_id_get_time:
478 * @id: The #GstClockID to query
480 * Get the time of the clock ID
482 * Returns: the time of the given clock id.
487 gst_clock_id_get_time (GstClockID id)
489 g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
491 return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);
496 * @id: The #GstClockID to wait on
497 * @jitter: (out) (allow-none): a pointer that will contain the jitter,
500 * Perform a blocking wait on @id.
501 * @id should have been created with gst_clock_new_single_shot_id()
502 * or gst_clock_new_periodic_id() and should not have been unscheduled
503 * with a call to gst_clock_id_unschedule().
505 * If the @jitter argument is not %NULL and this function returns #GST_CLOCK_OK
506 * or #GST_CLOCK_EARLY, it will contain the difference
507 * against the clock and the time of @id when this method was
509 * Positive values indicate how late @id was relative to the clock
510 * (in which case this function will return #GST_CLOCK_EARLY).
511 * Negative values indicate how much time was spent waiting on the clock
512 * before this function returned.
514 * Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned
515 * if the current clock time is past the time of @id, #GST_CLOCK_OK if
516 * @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was
517 * unscheduled with gst_clock_id_unschedule().
522 gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)
524 GstClockEntry *entry;
527 GstClockTime requested;
528 GstClockClass *cclass;
530 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
532 entry = (GstClockEntry *) id;
533 requested = GST_CLOCK_ENTRY_TIME (entry);
535 clock = g_weak_ref_get (&entry->ABI.clock);
536 if (G_UNLIKELY (clock == NULL))
539 /* can't sync on invalid times */
540 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
543 cclass = GST_CLOCK_GET_CLASS (clock);
545 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);
547 /* if we have a wait_jitter function, use that */
548 if (G_UNLIKELY (cclass->wait == NULL))
551 res = cclass->wait (clock, entry, jitter);
553 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
554 "done waiting entry %p, res: %d (%s)", id, res,
555 gst_clock_return_get_name (res));
557 if (entry->type == GST_CLOCK_ENTRY_PERIODIC)
558 entry->time = requested + entry->interval;
560 gst_object_unref (clock);
566 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
567 "invalid time requested, returning _BADTIME");
568 gst_object_unref (clock);
569 return GST_CLOCK_BADTIME;
573 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
574 gst_object_unref (clock);
575 return GST_CLOCK_UNSUPPORTED;
579 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock entry %p lost its clock", id);
580 return GST_CLOCK_ERROR;
585 * gst_clock_id_wait_async:
586 * @id: a #GstClockID to wait on
587 * @func: The callback function
588 * @user_data: User data passed in the callback
589 * @destroy_data: #GDestroyNotify for user_data
591 * Register a callback on the given #GstClockID @id with the given
592 * function and user_data. When passing a #GstClockID with an invalid
593 * time to this function, the callback will be called immediately
594 * with a time set to GST_CLOCK_TIME_NONE. The callback will
595 * be called when the time of @id has been reached.
597 * The callback @func can be invoked from any thread, either provided by the
598 * core or from a streaming thread. The application should be prepared for this.
600 * Returns: the result of the non blocking wait.
605 gst_clock_id_wait_async (GstClockID id,
606 GstClockCallback func, gpointer user_data, GDestroyNotify destroy_data)
608 GstClockEntry *entry;
611 GstClockClass *cclass;
612 GstClockTime requested;
614 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
615 g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
617 entry = (GstClockEntry *) id;
618 requested = GST_CLOCK_ENTRY_TIME (entry);
619 clock = g_weak_ref_get (&entry->ABI.clock);
620 if (G_UNLIKELY (clock == NULL))
623 /* can't sync on invalid times */
624 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
627 cclass = GST_CLOCK_GET_CLASS (clock);
629 if (G_UNLIKELY (cclass->wait_async == NULL))
633 entry->user_data = user_data;
634 entry->destroy_data = destroy_data;
636 res = cclass->wait_async (clock, entry);
638 gst_object_unref (clock);
644 (func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
645 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
646 "invalid time requested, returning _BADTIME");
647 gst_object_unref (clock);
648 return GST_CLOCK_BADTIME;
652 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
653 gst_object_unref (clock);
654 return GST_CLOCK_UNSUPPORTED;
658 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock entry %p lost its clock", id);
659 return GST_CLOCK_ERROR;
664 * gst_clock_id_unschedule:
665 * @id: The id to unschedule
667 * Cancel an outstanding request with @id. This can either
668 * be an outstanding async notification or a pending sync notification.
669 * After this call, @id cannot be used anymore to receive sync or
670 * async notifications, you need to create a new #GstClockID.
675 gst_clock_id_unschedule (GstClockID id)
677 GstClockEntry *entry;
679 GstClockClass *cclass;
681 g_return_if_fail (id != NULL);
683 entry = (GstClockEntry *) id;
684 clock = g_weak_ref_get (&entry->ABI.clock);
685 if (G_UNLIKELY (clock == NULL))
688 cclass = GST_CLOCK_GET_CLASS (clock);
690 if (G_LIKELY (cclass->unschedule))
691 cclass->unschedule (clock, entry);
693 gst_object_unref (clock);
698 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock entry %p lost its clock", id);
705 * GstClock abstract base class implementation
707 #define gst_clock_parent_class parent_class
708 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GstClock, gst_clock, GST_TYPE_OBJECT);
711 gst_clock_class_init (GstClockClass * klass)
713 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
715 gobject_class->dispose = gst_clock_dispose;
716 gobject_class->finalize = gst_clock_finalize;
717 gobject_class->set_property = gst_clock_set_property;
718 gobject_class->get_property = gst_clock_get_property;
720 g_object_class_install_property (gobject_class, PROP_WINDOW_SIZE,
721 g_param_spec_int ("window-size", "Window size",
722 "The size of the window used to calculate rate and offset", 2, 1024,
723 DEFAULT_WINDOW_SIZE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
724 g_object_class_install_property (gobject_class, PROP_WINDOW_THRESHOLD,
725 g_param_spec_int ("window-threshold", "Window threshold",
726 "The threshold to start calculating rate and offset", 2, 1024,
727 DEFAULT_WINDOW_THRESHOLD,
728 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
729 g_object_class_install_property (gobject_class, PROP_TIMEOUT,
730 g_param_spec_uint64 ("timeout", "Timeout",
731 "The amount of time, in nanoseconds, to sample master and slave clocks",
732 0, G_MAXUINT64, DEFAULT_TIMEOUT,
733 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
738 * @synced: if the clock is synced now
740 * Signaled on clocks with GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC set once
741 * the clock is synchronized, or when it completely lost synchronization.
742 * This signal will not be emitted on clocks without the flag.
744 * This signal will be emitted from an arbitrary thread, most likely not
745 * the application's main thread.
749 gst_clock_signals[SIGNAL_SYNCED] =
750 g_signal_new ("synced", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
752 g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_BOOLEAN);
756 gst_clock_init (GstClock * clock)
758 GstClockPrivate *priv;
760 clock->priv = priv = gst_clock_get_instance_private (clock);
764 priv->internal_calibration = 0;
765 priv->external_calibration = 0;
766 priv->rate_numerator = 1;
767 priv->rate_denominator = 1;
769 g_mutex_init (&priv->slave_lock);
770 g_cond_init (&priv->sync_cond);
771 priv->window_size = DEFAULT_WINDOW_SIZE;
772 priv->window_threshold = DEFAULT_WINDOW_THRESHOLD;
773 priv->filling = TRUE;
774 priv->time_index = 0;
775 priv->timeout = DEFAULT_TIMEOUT;
776 priv->times = g_new0 (GstClockTime, 4 * priv->window_size);
777 priv->times_temp = priv->times + 2 * priv->window_size;
781 gst_clock_dispose (GObject * object)
783 GstClock *clock = GST_CLOCK (object);
786 GST_OBJECT_LOCK (clock);
787 master_p = &clock->priv->master;
788 gst_object_replace ((GstObject **) master_p, NULL);
789 GST_OBJECT_UNLOCK (clock);
791 G_OBJECT_CLASS (parent_class)->dispose (object);
795 gst_clock_finalize (GObject * object)
797 GstClock *clock = GST_CLOCK (object);
799 GST_CLOCK_SLAVE_LOCK (clock);
800 if (clock->priv->clockid) {
801 gst_clock_id_unschedule (clock->priv->clockid);
802 gst_clock_id_unref (clock->priv->clockid);
803 clock->priv->clockid = NULL;
805 g_free (clock->priv->times);
806 clock->priv->times = NULL;
807 clock->priv->times_temp = NULL;
808 GST_CLOCK_SLAVE_UNLOCK (clock);
810 g_mutex_clear (&clock->priv->slave_lock);
811 g_cond_clear (&clock->priv->sync_cond);
813 G_OBJECT_CLASS (parent_class)->finalize (object);
817 * gst_clock_set_resolution:
818 * @clock: a #GstClock
819 * @resolution: The resolution to set
821 * Set the accuracy of the clock. Some clocks have the possibility to operate
822 * with different accuracy at the expense of more resource usage. There is
823 * normally no need to change the default resolution of a clock. The resolution
824 * of a clock can only be changed if the clock has the
825 * #GST_CLOCK_FLAG_CAN_SET_RESOLUTION flag set.
827 * Returns: the new resolution of the clock.
830 gst_clock_set_resolution (GstClock * clock, GstClockTime resolution)
832 GstClockPrivate *priv;
833 GstClockClass *cclass;
835 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
836 g_return_val_if_fail (resolution != 0, 0);
838 cclass = GST_CLOCK_GET_CLASS (clock);
841 if (cclass->change_resolution)
843 cclass->change_resolution (clock, priv->resolution, resolution);
845 return priv->resolution;
849 * gst_clock_get_resolution:
850 * @clock: a #GstClock
852 * Get the accuracy of the clock. The accuracy of the clock is the granularity
853 * of the values returned by gst_clock_get_time().
855 * Returns: the resolution of the clock in units of #GstClockTime.
860 gst_clock_get_resolution (GstClock * clock)
862 GstClockClass *cclass;
864 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
866 cclass = GST_CLOCK_GET_CLASS (clock);
868 if (cclass->get_resolution)
869 return cclass->get_resolution (clock);
874 /* FIXME 2.0: Remove clock parameter below */
876 * gst_clock_adjust_with_calibration:
877 * @clock: (allow-none): a #GstClock to use
878 * @internal_target: a clock time
879 * @cinternal: a reference internal time
880 * @cexternal: a reference external time
881 * @cnum: the numerator of the rate of the clock relative to its
883 * @cdenom: the denominator of the rate of the clock
885 * Converts the given @internal_target clock time to the external time,
886 * using the passed calibration parameters. This function performs the
887 * same calculation as gst_clock_adjust_unlocked() when called using the
888 * current calibration parameters, but doesn't ensure a monotonically
889 * increasing result as gst_clock_adjust_unlocked() does.
891 * Note: The @clock parameter is unused and can be NULL
893 * Returns: the converted time of the clock.
898 gst_clock_adjust_with_calibration (GstClock * clock,
899 GstClockTime internal_target, GstClockTime cinternal,
900 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
904 /* avoid divide by 0 */
905 if (G_UNLIKELY (cdenom == 0))
908 /* The formula is (internal - cinternal) * cnum / cdenom + cexternal
910 * Since we do math on unsigned 64-bit ints we have to special case for
911 * internal < cinternal to get the sign right. this case is not very common,
914 if (G_LIKELY (internal_target >= cinternal)) {
915 ret = internal_target - cinternal;
916 ret = gst_util_uint64_scale (ret, cnum, cdenom);
919 ret = cinternal - internal_target;
920 ret = gst_util_uint64_scale (ret, cnum, cdenom);
922 if (G_LIKELY (cexternal > ret))
923 ret = cexternal - ret;
932 * gst_clock_adjust_unlocked:
933 * @clock: a #GstClock to use
934 * @internal: a clock time
936 * Converts the given @internal clock time to the external time, adjusting for the
937 * rate and reference time set with gst_clock_set_calibration() and making sure
938 * that the returned time is increasing. This function should be called with the
939 * clock's OBJECT_LOCK held and is mainly used by clock subclasses.
941 * This function is the reverse of gst_clock_unadjust_unlocked().
943 * Returns: the converted time of the clock.
946 gst_clock_adjust_unlocked (GstClock * clock, GstClockTime internal)
948 GstClockTime ret, cinternal, cexternal, cnum, cdenom;
949 GstClockPrivate *priv = clock->priv;
951 /* get calibration values for readability */
952 cinternal = priv->internal_calibration;
953 cexternal = priv->external_calibration;
954 cnum = priv->rate_numerator;
955 cdenom = priv->rate_denominator;
958 gst_clock_adjust_with_calibration (clock, internal, cinternal, cexternal,
961 /* make sure the time is increasing */
962 priv->last_time = MAX (ret, priv->last_time);
964 return priv->last_time;
967 /* FIXME 2.0: Remove clock parameter below */
969 * gst_clock_unadjust_with_calibration:
970 * @clock: (allow-none): a #GstClock to use
971 * @external_target: a clock time
972 * @cinternal: a reference internal time
973 * @cexternal: a reference external time
974 * @cnum: the numerator of the rate of the clock relative to its
976 * @cdenom: the denominator of the rate of the clock
978 * Converts the given @external_target clock time to the internal time,
979 * using the passed calibration parameters. This function performs the
980 * same calculation as gst_clock_unadjust_unlocked() when called using the
981 * current calibration parameters.
983 * Note: The @clock parameter is unused and can be NULL
985 * Returns: the converted time of the clock.
990 gst_clock_unadjust_with_calibration (GstClock * clock,
991 GstClockTime external_target, GstClockTime cinternal,
992 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
996 /* avoid divide by 0 */
997 if (G_UNLIKELY (cnum == 0))
1000 /* The formula is (external - cexternal) * cdenom / cnum + cinternal */
1001 if (G_LIKELY (external_target >= cexternal)) {
1002 ret = external_target - cexternal;
1003 ret = gst_util_uint64_scale (ret, cdenom, cnum);
1006 ret = cexternal - external_target;
1007 ret = gst_util_uint64_scale (ret, cdenom, cnum);
1008 if (G_LIKELY (cinternal > ret))
1009 ret = cinternal - ret;
1018 * gst_clock_unadjust_unlocked:
1019 * @clock: a #GstClock to use
1020 * @external: an external clock time
1022 * Converts the given @external clock time to the internal time of @clock,
1023 * using the rate and reference time set with gst_clock_set_calibration().
1024 * This function should be called with the clock's OBJECT_LOCK held and
1025 * is mainly used by clock subclasses.
1027 * This function is the reverse of gst_clock_adjust_unlocked().
1029 * Returns: the internal time of the clock corresponding to @external.
1032 gst_clock_unadjust_unlocked (GstClock * clock, GstClockTime external)
1034 GstClockTime cinternal, cexternal, cnum, cdenom;
1035 GstClockPrivate *priv = clock->priv;
1037 /* get calibration values for readability */
1038 cinternal = priv->internal_calibration;
1039 cexternal = priv->external_calibration;
1040 cnum = priv->rate_numerator;
1041 cdenom = priv->rate_denominator;
1043 return gst_clock_unadjust_with_calibration (clock, external, cinternal,
1044 cexternal, cnum, cdenom);
1048 * gst_clock_get_internal_time:
1049 * @clock: a #GstClock to query
1051 * Gets the current internal time of the given clock. The time is returned
1052 * unadjusted for the offset and the rate.
1054 * Returns: the internal time of the clock. Or GST_CLOCK_TIME_NONE when
1055 * given invalid input.
1060 gst_clock_get_internal_time (GstClock * clock)
1063 GstClockClass *cclass;
1065 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1067 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (clock,
1068 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC) && !clock->priv->synced))
1069 GST_CAT_WARNING_OBJECT (GST_CAT_CLOCK, clock,
1070 "clock is not synchronized yet");
1072 cclass = GST_CLOCK_GET_CLASS (clock);
1074 if (G_UNLIKELY (cclass->get_internal_time == NULL))
1077 ret = cclass->get_internal_time (clock);
1079 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "internal time %" GST_TIME_FORMAT,
1080 GST_TIME_ARGS (ret));
1087 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1088 "internal time not supported, return 0");
1089 return G_GINT64_CONSTANT (0);
1094 * gst_clock_get_time:
1095 * @clock: a #GstClock to query
1097 * Gets the current time of the given clock. The time is always
1098 * monotonically increasing and adjusted according to the current
1101 * Returns: the time of the clock. Or GST_CLOCK_TIME_NONE when
1102 * given invalid input.
1107 gst_clock_get_time (GstClock * clock)
1112 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1115 /* reget the internal time when we retry to get the most current
1117 ret = gst_clock_get_internal_time (clock);
1119 seq = read_seqbegin (clock);
1120 /* this will scale for rate and offset */
1121 ret = gst_clock_adjust_unlocked (clock, ret);
1122 } while (read_seqretry (clock, seq));
1124 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "adjusted time %" GST_TIME_FORMAT,
1125 GST_TIME_ARGS (ret));
1131 * gst_clock_set_calibration:
1132 * @clock: a #GstClock to calibrate
1133 * @internal: a reference internal time
1134 * @external: a reference external time
1135 * @rate_num: the numerator of the rate of the clock relative to its
1137 * @rate_denom: the denominator of the rate of the clock
1139 * Adjusts the rate and time of @clock. A rate of 1/1 is the normal speed of
1140 * the clock. Values bigger than 1/1 make the clock go faster.
1142 * @internal and @external are calibration parameters that arrange that
1143 * gst_clock_get_time() should have been @external at internal time @internal.
1144 * This internal time should not be in the future; that is, it should be less
1145 * than the value of gst_clock_get_internal_time() when this function is called.
1147 * Subsequent calls to gst_clock_get_time() will return clock times computed as
1151 * time = (internal_time - internal) * rate_num / rate_denom + external
1154 * This formula is implemented in gst_clock_adjust_unlocked(). Of course, it
1155 * tries to do the integer arithmetic as precisely as possible.
1157 * Note that gst_clock_get_time() always returns increasing values so when you
1158 * move the clock backwards, gst_clock_get_time() will report the previous value
1159 * until the clock catches up.
1164 gst_clock_set_calibration (GstClock * clock, GstClockTime internal, GstClockTime
1165 external, GstClockTime rate_num, GstClockTime rate_denom)
1167 GstClockPrivate *priv;
1169 g_return_if_fail (GST_IS_CLOCK (clock));
1170 g_return_if_fail (rate_num != GST_CLOCK_TIME_NONE);
1171 g_return_if_fail (rate_denom > 0 && rate_denom != GST_CLOCK_TIME_NONE);
1175 write_seqlock (clock);
1176 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1177 "internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT " %"
1178 G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT " = %f", GST_TIME_ARGS (internal),
1179 GST_TIME_ARGS (external), rate_num, rate_denom,
1180 gst_guint64_to_gdouble (rate_num) / gst_guint64_to_gdouble (rate_denom));
1182 priv->internal_calibration = internal;
1183 priv->external_calibration = external;
1184 priv->rate_numerator = rate_num;
1185 priv->rate_denominator = rate_denom;
1186 write_sequnlock (clock);
1190 * gst_clock_get_calibration:
1191 * @clock: a #GstClock
1192 * @internal: (out) (allow-none): a location to store the internal time
1193 * @external: (out) (allow-none): a location to store the external time
1194 * @rate_num: (out) (allow-none): a location to store the rate numerator
1195 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1197 * Gets the internal rate and reference time of @clock. See
1198 * gst_clock_set_calibration() for more information.
1200 * @internal, @external, @rate_num, and @rate_denom can be left %NULL if the
1201 * caller is not interested in the values.
1206 gst_clock_get_calibration (GstClock * clock, GstClockTime * internal,
1207 GstClockTime * external, GstClockTime * rate_num, GstClockTime * rate_denom)
1210 GstClockPrivate *priv;
1212 g_return_if_fail (GST_IS_CLOCK (clock));
1217 seq = read_seqbegin (clock);
1219 *rate_num = priv->rate_numerator;
1221 *rate_denom = priv->rate_denominator;
1223 *external = priv->external_calibration;
1225 *internal = priv->internal_calibration;
1226 } while (read_seqretry (clock, seq));
1229 /* will be called repeatedly to sample the master and slave clock
1230 * to recalibrate the clock */
1232 gst_clock_slave_callback (GstClock * master, GstClockTime time,
1233 GstClockID id, GstClock * clock)
1235 GstClockTime stime, mtime;
1238 if (!gst_clock_is_synced (clock)) {
1239 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1240 "Slave clock is not synced yet");
1244 stime = gst_clock_get_internal_time (clock);
1245 mtime = gst_clock_get_time (master);
1247 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1248 "master %" GST_TIME_FORMAT ", slave %" GST_TIME_FORMAT,
1249 GST_TIME_ARGS (mtime), GST_TIME_ARGS (stime));
1251 gst_clock_add_observation (clock, stime, mtime, &r_squared);
1253 /* FIXME, we can use the r_squared value to adjust the timeout
1254 * value of the clockid */
1260 * gst_clock_set_master:
1261 * @clock: a #GstClock
1262 * @master: (allow-none): a master #GstClock
1264 * Set @master as the master clock for @clock. @clock will be automatically
1265 * calibrated so that gst_clock_get_time() reports the same time as the
1268 * A clock provider that slaves its clock to a master can get the current
1269 * calibration values with gst_clock_get_calibration().
1271 * @master can be %NULL in which case @clock will not be slaved anymore. It will
1272 * however keep reporting its time adjusted with the last configured rate
1275 * Returns: %TRUE if the clock is capable of being slaved to a master clock.
1276 * Trying to set a master on a clock without the
1277 * #GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return %FALSE.
1282 gst_clock_set_master (GstClock * clock, GstClock * master)
1284 GstClock **master_p;
1285 GstClockPrivate *priv;
1287 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1288 g_return_val_if_fail (master != clock, FALSE);
1290 GST_OBJECT_LOCK (clock);
1291 /* we always allow setting the master to NULL */
1292 if (master && !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER))
1294 if (master && !gst_clock_is_synced (master))
1295 goto master_not_synced;
1297 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1298 "slaving %p to master clock %p", clock, master);
1299 GST_OBJECT_UNLOCK (clock);
1303 GST_CLOCK_SLAVE_LOCK (clock);
1304 if (priv->clockid) {
1305 gst_clock_id_unschedule (priv->clockid);
1306 gst_clock_id_unref (priv->clockid);
1307 priv->clockid = NULL;
1310 priv->filling = TRUE;
1311 priv->time_index = 0;
1312 /* use the master periodic id to schedule sampling and
1313 * clock calibration. */
1314 priv->clockid = gst_clock_new_periodic_id (master,
1315 gst_clock_get_time (master), priv->timeout);
1316 gst_clock_id_wait_async (priv->clockid,
1317 (GstClockCallback) gst_clock_slave_callback,
1318 gst_object_ref (clock), (GDestroyNotify) gst_object_unref);
1320 GST_CLOCK_SLAVE_UNLOCK (clock);
1322 GST_OBJECT_LOCK (clock);
1323 master_p = &priv->master;
1324 gst_object_replace ((GstObject **) master_p, (GstObject *) master);
1325 GST_OBJECT_UNLOCK (clock);
1332 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1333 "cannot be slaved to a master clock");
1334 GST_OBJECT_UNLOCK (clock);
1340 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, master,
1341 "master clock is not synced yet");
1342 GST_OBJECT_UNLOCK (clock);
1348 * gst_clock_get_master:
1349 * @clock: a #GstClock
1351 * Get the master clock that @clock is slaved to or %NULL when the clock is
1352 * not slaved to any master clock.
1354 * Returns: (transfer full) (nullable): a master #GstClock or %NULL
1355 * when this clock is not slaved to a master clock. Unref after
1361 gst_clock_get_master (GstClock * clock)
1363 GstClock *result = NULL;
1364 GstClockPrivate *priv;
1366 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
1370 GST_OBJECT_LOCK (clock);
1372 result = gst_object_ref (priv->master);
1373 GST_OBJECT_UNLOCK (clock);
1379 * gst_clock_id_get_clock:
1380 * @id: a #GstClockID
1382 * This function returns the underlying clock.
1384 * Returns: (transfer full) (nullable): a #GstClock or %NULL when the
1385 * underlying clock has been freed. Unref after usage.
1390 gst_clock_id_get_clock (GstClockID id)
1392 GstClockEntry *entry;
1394 g_return_val_if_fail (id != NULL, NULL);
1396 entry = (GstClockEntry *) id;
1397 return g_weak_ref_get (&entry->ABI.clock);
1401 * gst_clock_id_uses_clock:
1402 * @id: a #GstClockID to check
1403 * @clock: a #GstClock to compare against
1405 * This function returns whether @id uses @clock as the underlying clock.
1406 * @clock can be NULL, in which case the return value indicates whether
1407 * the underlying clock has been freed. If this is the case, the @id is
1408 * no longer usable and should be freed.
1410 * Returns: whether the clock @id uses the same underlying #GstClock @clock.
1415 gst_clock_id_uses_clock (GstClockID id, GstClock * clock)
1417 GstClockEntry *entry;
1418 GstClock *entry_clock;
1419 gboolean ret = FALSE;
1421 g_return_val_if_fail (id != NULL, FALSE);
1423 entry = (GstClockEntry *) id;
1424 entry_clock = g_weak_ref_get (&entry->ABI.clock);
1425 if (entry_clock == clock)
1428 if (G_LIKELY (entry_clock != NULL))
1429 gst_object_unref (entry_clock);
1436 * gst_clock_add_observation:
1437 * @clock: a #GstClock
1438 * @slave: a time on the slave
1439 * @master: a time on the master
1440 * @r_squared: (out): a pointer to hold the result
1442 * The time @master of the master clock and the time @slave of the slave
1443 * clock are added to the list of observations. If enough observations
1444 * are available, a linear regression algorithm is run on the
1445 * observations and @clock is recalibrated.
1447 * If this functions returns %TRUE, @r_squared will contain the
1448 * correlation coefficient of the interpolation. A value of 1.0
1449 * means a perfect regression was performed. This value can
1450 * be used to control the sampling frequency of the master and slave
1453 * Returns: %TRUE if enough observations were added to run the
1454 * regression algorithm.
1459 gst_clock_add_observation (GstClock * clock, GstClockTime slave,
1460 GstClockTime master, gdouble * r_squared)
1462 GstClockTime m_num, m_denom, b, xbase;
1464 if (!gst_clock_add_observation_unapplied (clock, slave, master, r_squared,
1465 &xbase, &b, &m_num, &m_denom))
1468 /* if we have a valid regression, adjust the clock */
1469 gst_clock_set_calibration (clock, xbase, b, m_num, m_denom);
1475 * gst_clock_add_observation_unapplied:
1476 * @clock: a #GstClock
1477 * @slave: a time on the slave
1478 * @master: a time on the master
1479 * @r_squared: (out): a pointer to hold the result
1480 * @internal: (out) (allow-none): a location to store the internal time
1481 * @external: (out) (allow-none): a location to store the external time
1482 * @rate_num: (out) (allow-none): a location to store the rate numerator
1483 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1485 * Add a clock observation to the internal slaving algorithm the same as
1486 * gst_clock_add_observation(), and return the result of the master clock
1487 * estimation, without updating the internal calibration.
1489 * The caller can then take the results and call gst_clock_set_calibration()
1490 * with the values, or some modified version of them.
1495 gst_clock_add_observation_unapplied (GstClock * clock, GstClockTime slave,
1496 GstClockTime master, gdouble * r_squared,
1497 GstClockTime * internal, GstClockTime * external,
1498 GstClockTime * rate_num, GstClockTime * rate_denom)
1500 GstClockTime m_num, m_denom, b, xbase;
1501 GstClockPrivate *priv;
1504 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1505 g_return_val_if_fail (r_squared != NULL, FALSE);
1509 GST_CLOCK_SLAVE_LOCK (clock);
1511 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1512 "adding observation slave %" GST_TIME_FORMAT ", master %" GST_TIME_FORMAT,
1513 GST_TIME_ARGS (slave), GST_TIME_ARGS (master));
1515 priv->times[(2 * priv->time_index)] = slave;
1516 priv->times[(2 * priv->time_index) + 1] = master;
1519 if (G_UNLIKELY (priv->time_index == priv->window_size)) {
1520 priv->filling = FALSE;
1521 priv->time_index = 0;
1524 if (G_UNLIKELY (priv->filling && priv->time_index < priv->window_threshold))
1527 n = priv->filling ? priv->time_index : priv->window_size;
1528 if (!gst_calculate_linear_regression (priv->times, priv->times_temp, n,
1529 &m_num, &m_denom, &b, &xbase, r_squared))
1532 GST_CLOCK_SLAVE_UNLOCK (clock);
1534 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1535 "adjusting clock to m=%" G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT ", b=%"
1536 G_GUINT64_FORMAT " (rsquared=%g)", m_num, m_denom, b, *r_squared);
1545 *rate_denom = m_denom;
1551 GST_CLOCK_SLAVE_UNLOCK (clock);
1556 /* no valid regression has been done, ignore the result then */
1557 GST_CLOCK_SLAVE_UNLOCK (clock);
1563 * gst_clock_set_timeout:
1564 * @clock: a #GstClock
1565 * @timeout: a timeout
1567 * Set the amount of time, in nanoseconds, to sample master and slave
1571 gst_clock_set_timeout (GstClock * clock, GstClockTime timeout)
1573 g_return_if_fail (GST_IS_CLOCK (clock));
1575 GST_CLOCK_SLAVE_LOCK (clock);
1576 clock->priv->timeout = timeout;
1577 GST_CLOCK_SLAVE_UNLOCK (clock);
1581 * gst_clock_get_timeout:
1582 * @clock: a #GstClock
1584 * Get the amount of time that master and slave clocks are sampled.
1586 * Returns: the interval between samples.
1589 gst_clock_get_timeout (GstClock * clock)
1591 GstClockTime result;
1593 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1595 GST_CLOCK_SLAVE_LOCK (clock);
1596 result = clock->priv->timeout;
1597 GST_CLOCK_SLAVE_UNLOCK (clock);
1603 gst_clock_set_property (GObject * object, guint prop_id,
1604 const GValue * value, GParamSpec * pspec)
1607 GstClockPrivate *priv;
1609 clock = GST_CLOCK (object);
1613 case PROP_WINDOW_SIZE:
1614 GST_CLOCK_SLAVE_LOCK (clock);
1615 priv->window_size = g_value_get_int (value);
1616 priv->window_threshold = MIN (priv->window_threshold, priv->window_size);
1617 priv->times = g_renew (GstClockTime, priv->times, 4 * priv->window_size);
1618 priv->times_temp = priv->times + 2 * priv->window_size;
1619 /* restart calibration */
1620 priv->filling = TRUE;
1621 priv->time_index = 0;
1622 GST_CLOCK_SLAVE_UNLOCK (clock);
1624 case PROP_WINDOW_THRESHOLD:
1625 GST_CLOCK_SLAVE_LOCK (clock);
1626 priv->window_threshold = MIN (g_value_get_int (value), priv->window_size);
1627 GST_CLOCK_SLAVE_UNLOCK (clock);
1630 gst_clock_set_timeout (clock, g_value_get_uint64 (value));
1633 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1639 gst_clock_get_property (GObject * object, guint prop_id,
1640 GValue * value, GParamSpec * pspec)
1643 GstClockPrivate *priv;
1645 clock = GST_CLOCK (object);
1649 case PROP_WINDOW_SIZE:
1650 GST_CLOCK_SLAVE_LOCK (clock);
1651 g_value_set_int (value, priv->window_size);
1652 GST_CLOCK_SLAVE_UNLOCK (clock);
1654 case PROP_WINDOW_THRESHOLD:
1655 GST_CLOCK_SLAVE_LOCK (clock);
1656 g_value_set_int (value, priv->window_threshold);
1657 GST_CLOCK_SLAVE_UNLOCK (clock);
1660 g_value_set_uint64 (value, gst_clock_get_timeout (clock));
1663 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1670 * gst_clock_wait_for_sync:
1671 * @clock: a GstClock
1672 * @timeout: timeout for waiting or %GST_CLOCK_TIME_NONE
1674 * Waits until @clock is synced for reporting the current time. If @timeout
1675 * is %GST_CLOCK_TIME_NONE it will wait forever, otherwise it will time out
1676 * after @timeout nanoseconds.
1678 * For asynchronous waiting, the GstClock::synced signal can be used.
1680 * This returns immediately with TRUE if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1681 * is not set on the clock, or if the clock is already synced.
1683 * Returns: %TRUE if waiting was successful, or %FALSE on timeout
1688 gst_clock_wait_for_sync (GstClock * clock, GstClockTime timeout)
1690 gboolean timed_out = FALSE;
1692 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1694 GST_OBJECT_LOCK (clock);
1695 if (!GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1696 || clock->priv->synced) {
1697 GST_OBJECT_UNLOCK (clock);
1701 if (timeout != GST_CLOCK_TIME_NONE) {
1702 gint64 end_time = g_get_monotonic_time () + gst_util_uint64_scale (timeout,
1703 G_TIME_SPAN_SECOND, GST_SECOND);
1705 while (!clock->priv->synced && !timed_out) {
1707 !g_cond_wait_until (&clock->priv->sync_cond,
1708 GST_OBJECT_GET_LOCK (clock), end_time);
1712 while (!clock->priv->synced) {
1713 g_cond_wait (&clock->priv->sync_cond, GST_OBJECT_GET_LOCK (clock));
1716 GST_OBJECT_UNLOCK (clock);
1722 * gst_clock_is_synced:
1723 * @clock: a GstClock
1725 * Checks if the clock is currently synced.
1727 * This returns if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC is not set on the clock.
1729 * Returns: %TRUE if the clock is currently synced
1734 gst_clock_is_synced (GstClock * clock)
1736 g_return_val_if_fail (GST_IS_CLOCK (clock), TRUE);
1738 return !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1739 || clock->priv->synced;
1743 * gst_clock_set_synced:
1744 * @clock: a GstClock
1745 * @synced: if the clock is synced
1747 * Sets @clock to synced and emits the GstClock::synced signal, and wakes up any
1748 * thread waiting in gst_clock_wait_for_sync().
1750 * This function must only be called if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1751 * is set on the clock, and is intended to be called by subclasses only.
1756 gst_clock_set_synced (GstClock * clock, gboolean synced)
1758 g_return_if_fail (GST_IS_CLOCK (clock));
1759 g_return_if_fail (GST_OBJECT_FLAG_IS_SET (clock,
1760 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC));
1762 GST_OBJECT_LOCK (clock);
1763 if (clock->priv->synced != ! !synced) {
1764 clock->priv->synced = ! !synced;
1765 g_cond_signal (&clock->priv->sync_cond);
1766 GST_OBJECT_UNLOCK (clock);
1767 g_signal_emit (clock, gst_clock_signals[SIGNAL_SYNCED], 0, ! !synced);
1769 GST_OBJECT_UNLOCK (clock);