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;
176 #define GST_CLOCK_ENTRY_CLOCK_WEAK_REF(entry) (&((GstClockEntryImpl *)(entry))->clock)
179 #define read_seqbegin(clock) \
180 g_atomic_int_get (&clock->priv->post_count);
182 static inline gboolean
183 read_seqretry (GstClock * clock, gint seq)
185 /* no retry if the seqnum did not change */
186 if (G_LIKELY (seq == g_atomic_int_get (&clock->priv->pre_count)))
189 /* wait for the writer to finish and retry */
190 GST_OBJECT_LOCK (clock);
191 GST_OBJECT_UNLOCK (clock);
195 #define write_seqlock(clock) \
197 GST_OBJECT_LOCK (clock); \
198 g_atomic_int_inc (&clock->priv->pre_count); \
201 #define write_sequnlock(clock) \
203 g_atomic_int_inc (&clock->priv->post_count); \
204 GST_OBJECT_UNLOCK (clock); \
207 #ifndef GST_DISABLE_GST_DEBUG
209 gst_clock_return_get_name (GstClockReturn ret)
214 case GST_CLOCK_EARLY:
216 case GST_CLOCK_UNSCHEDULED:
217 return "unscheduled";
220 case GST_CLOCK_BADTIME:
222 case GST_CLOCK_ERROR:
224 case GST_CLOCK_UNSUPPORTED:
225 return "unsupported";
234 #endif /* GST_DISABLE_GST_DEBUG */
236 static void gst_clock_dispose (GObject * object);
237 static void gst_clock_finalize (GObject * object);
239 static void gst_clock_set_property (GObject * object, guint prop_id,
240 const GValue * value, GParamSpec * pspec);
241 static void gst_clock_get_property (GObject * object, guint prop_id,
242 GValue * value, GParamSpec * pspec);
244 static guint gst_clock_signals[SIGNAL_LAST] = { 0 };
247 gst_clock_entry_new (GstClock * clock, GstClockTime time,
248 GstClockTime interval, GstClockEntryType type)
250 GstClockEntry *entry;
252 entry = (GstClockEntry *) g_slice_new (GstClockEntryImpl);
254 /* FIXME: add tracer hook for struct allocations such as clock entries */
256 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
257 "created entry %p, time %" GST_TIME_FORMAT, entry, GST_TIME_ARGS (time));
260 #ifndef GST_REMOVE_DEPRECATED
261 #ifndef GST_DISABLE_DEPRECATED
262 entry->clock = clock;
264 entry->_clock = clock;
267 g_weak_ref_init (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry), clock);
270 entry->interval = interval;
271 entry->status = GST_CLOCK_OK;
273 entry->user_data = NULL;
274 entry->destroy_data = NULL;
275 entry->unscheduled = FALSE;
276 entry->woken_up = FALSE;
278 return (GstClockID) entry;
281 /* WARNING : Does not modify the refcount
282 * WARNING : Do not use if a pending clock operation is happening on that entry */
284 gst_clock_entry_reinit (GstClock * clock, GstClockEntry * entry,
285 GstClockTime time, GstClockTime interval, GstClockEntryType type)
287 g_return_val_if_fail (entry->status != GST_CLOCK_BUSY, FALSE);
288 g_return_val_if_fail (gst_clock_id_uses_clock ((GstClockID) entry, clock),
293 entry->interval = interval;
294 entry->status = GST_CLOCK_OK;
295 entry->unscheduled = FALSE;
296 entry->woken_up = FALSE;
302 * gst_clock_single_shot_id_reinit:
303 * @clock: a #GstClock
305 * @time: The requested time.
307 * Reinitializes the provided single shot @id to the provided time. Does not
308 * modify the reference count.
310 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
311 * @time, else %FALSE.
314 gst_clock_single_shot_id_reinit (GstClock * clock, GstClockID id,
317 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, time,
318 GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
322 * gst_clock_periodic_id_reinit:
323 * @clock: a #GstClock
325 * @start_time: the requested start time
326 * @interval: the requested interval
328 * Reinitializes the provided periodic @id to the provided start time and
329 * interval. Does not modify the reference count.
331 * Returns: %TRUE if the GstClockID could be reinitialized to the provided
332 * @time, else %FALSE.
335 gst_clock_periodic_id_reinit (GstClock * clock, GstClockID id,
336 GstClockTime start_time, GstClockTime interval)
338 return gst_clock_entry_reinit (clock, (GstClockEntry *) id, start_time,
339 interval, GST_CLOCK_ENTRY_PERIODIC);
344 * @id: The #GstClockID to ref
346 * Increase the refcount of given @id.
348 * Returns: (transfer full): The same #GstClockID with increased refcount.
353 gst_clock_id_ref (GstClockID id)
355 g_return_val_if_fail (id != NULL, NULL);
357 g_atomic_int_inc (&((GstClockEntry *) id)->refcount);
363 _gst_clock_id_free (GstClockID id)
365 GstClockEntry *entry;
366 g_return_if_fail (id != NULL);
368 GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);
369 entry = (GstClockEntry *) id;
370 if (entry->destroy_data)
371 entry->destroy_data (entry->user_data);
373 g_weak_ref_clear (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry));
375 /* FIXME: add tracer hook for struct allocations such as clock entries */
377 g_slice_free (GstClockEntryImpl, (GstClockEntryImpl *) id);
381 * gst_clock_id_unref:
382 * @id: (transfer full): The #GstClockID to unref
384 * Unref given @id. When the refcount reaches 0 the
385 * #GstClockID will be freed.
390 gst_clock_id_unref (GstClockID id)
394 g_return_if_fail (id != NULL);
396 zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);
397 /* if we ended up with the refcount at zero, free the id */
399 _gst_clock_id_free (id);
404 * gst_clock_new_single_shot_id:
405 * @clock: The #GstClockID to get a single shot notification from
406 * @time: the requested time
408 * Get a #GstClockID from @clock to trigger a single shot
409 * notification at the requested time. The single shot id should be
410 * unreffed after usage.
412 * Free-function: gst_clock_id_unref
414 * Returns: (transfer full): a #GstClockID that can be used to request the
420 gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)
422 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
424 return gst_clock_entry_new (clock,
425 time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
429 * gst_clock_new_periodic_id:
430 * @clock: The #GstClockID to get a periodic notification id from
431 * @start_time: the requested start time
432 * @interval: the requested interval
434 * Get an ID from @clock to trigger a periodic notification.
435 * The periodic notifications will start at time @start_time and
436 * will then be fired with the given @interval. @id should be unreffed
439 * Free-function: gst_clock_id_unref
441 * Returns: (transfer full): a #GstClockID that can be used to request the
447 gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,
448 GstClockTime interval)
450 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
451 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);
452 g_return_val_if_fail (interval != 0, NULL);
453 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);
455 return gst_clock_entry_new (clock,
456 start_time, interval, GST_CLOCK_ENTRY_PERIODIC);
460 * gst_clock_id_compare_func:
461 * @id1: A #GstClockID
462 * @id2: A #GstClockID to compare with
464 * Compares the two #GstClockID instances. This function can be used
465 * as a GCompareFunc when sorting ids.
467 * Returns: negative value if a < b; zero if a = b; positive value if a > b
472 gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)
474 GstClockEntry *entry1, *entry2;
476 entry1 = (GstClockEntry *) id1;
477 entry2 = (GstClockEntry *) id2;
479 if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {
482 if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {
489 * gst_clock_id_get_time:
490 * @id: The #GstClockID to query
492 * Get the time of the clock ID
494 * Returns: the time of the given clock id.
499 gst_clock_id_get_time (GstClockID id)
501 g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
503 return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);
508 * @id: The #GstClockID to wait on
509 * @jitter: (out) (allow-none): a pointer that will contain the jitter,
512 * Perform a blocking wait on @id.
513 * @id should have been created with gst_clock_new_single_shot_id()
514 * or gst_clock_new_periodic_id() and should not have been unscheduled
515 * with a call to gst_clock_id_unschedule().
517 * If the @jitter argument is not %NULL and this function returns #GST_CLOCK_OK
518 * or #GST_CLOCK_EARLY, it will contain the difference
519 * against the clock and the time of @id when this method was
521 * Positive values indicate how late @id was relative to the clock
522 * (in which case this function will return #GST_CLOCK_EARLY).
523 * Negative values indicate how much time was spent waiting on the clock
524 * before this function returned.
526 * Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned
527 * if the current clock time is past the time of @id, #GST_CLOCK_OK if
528 * @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was
529 * unscheduled with gst_clock_id_unschedule().
534 gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)
536 GstClockEntry *entry;
539 GstClockTime requested;
540 GstClockClass *cclass;
542 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
544 entry = (GstClockEntry *) id;
545 requested = GST_CLOCK_ENTRY_TIME (entry);
547 clock = g_weak_ref_get (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry));
548 if (G_UNLIKELY (clock == NULL))
551 /* can't sync on invalid times */
552 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
555 cclass = GST_CLOCK_GET_CLASS (clock);
557 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);
559 /* if we have a wait_jitter function, use that */
560 if (G_UNLIKELY (cclass->wait == NULL))
563 res = cclass->wait (clock, entry, jitter);
565 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
566 "done waiting entry %p, res: %d (%s)", id, res,
567 gst_clock_return_get_name (res));
569 if (entry->type == GST_CLOCK_ENTRY_PERIODIC)
570 entry->time = requested + entry->interval;
572 gst_object_unref (clock);
578 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
579 "invalid time requested, returning _BADTIME");
580 gst_object_unref (clock);
581 return GST_CLOCK_BADTIME;
585 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
586 gst_object_unref (clock);
587 return GST_CLOCK_UNSUPPORTED;
591 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock entry %p lost its clock", id);
592 return GST_CLOCK_ERROR;
597 * gst_clock_id_wait_async:
598 * @id: a #GstClockID to wait on
599 * @func: The callback function
600 * @user_data: User data passed in the callback
601 * @destroy_data: #GDestroyNotify for user_data
603 * Register a callback on the given #GstClockID @id with the given
604 * function and user_data. When passing a #GstClockID with an invalid
605 * time to this function, the callback will be called immediately
606 * with a time set to GST_CLOCK_TIME_NONE. The callback will
607 * be called when the time of @id has been reached.
609 * The callback @func can be invoked from any thread, either provided by the
610 * core or from a streaming thread. The application should be prepared for this.
612 * Returns: the result of the non blocking wait.
617 gst_clock_id_wait_async (GstClockID id,
618 GstClockCallback func, gpointer user_data, GDestroyNotify destroy_data)
620 GstClockEntry *entry;
623 GstClockClass *cclass;
624 GstClockTime requested;
626 g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
627 g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
629 entry = (GstClockEntry *) id;
630 requested = GST_CLOCK_ENTRY_TIME (entry);
631 clock = g_weak_ref_get (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry));
632 if (G_UNLIKELY (clock == NULL))
635 /* can't sync on invalid times */
636 if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
639 cclass = GST_CLOCK_GET_CLASS (clock);
641 if (G_UNLIKELY (cclass->wait_async == NULL))
645 entry->user_data = user_data;
646 entry->destroy_data = destroy_data;
648 res = cclass->wait_async (clock, entry);
650 gst_object_unref (clock);
656 (func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
657 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
658 "invalid time requested, returning _BADTIME");
659 gst_object_unref (clock);
660 return GST_CLOCK_BADTIME;
664 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
665 gst_object_unref (clock);
666 return GST_CLOCK_UNSUPPORTED;
670 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock entry %p lost its clock", id);
671 return GST_CLOCK_ERROR;
676 * gst_clock_id_unschedule:
677 * @id: The id to unschedule
679 * Cancel an outstanding request with @id. This can either
680 * be an outstanding async notification or a pending sync notification.
681 * After this call, @id cannot be used anymore to receive sync or
682 * async notifications, you need to create a new #GstClockID.
687 gst_clock_id_unschedule (GstClockID id)
689 GstClockEntry *entry;
691 GstClockClass *cclass;
693 g_return_if_fail (id != NULL);
695 entry = (GstClockEntry *) id;
696 clock = g_weak_ref_get (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry));
697 if (G_UNLIKELY (clock == NULL))
700 cclass = GST_CLOCK_GET_CLASS (clock);
702 if (G_LIKELY (cclass->unschedule))
703 cclass->unschedule (clock, entry);
705 gst_object_unref (clock);
710 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock entry %p lost its clock", id);
717 * GstClock abstract base class implementation
719 #define gst_clock_parent_class parent_class
720 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GstClock, gst_clock, GST_TYPE_OBJECT);
723 gst_clock_class_init (GstClockClass * klass)
725 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
727 gobject_class->dispose = gst_clock_dispose;
728 gobject_class->finalize = gst_clock_finalize;
729 gobject_class->set_property = gst_clock_set_property;
730 gobject_class->get_property = gst_clock_get_property;
732 g_object_class_install_property (gobject_class, PROP_WINDOW_SIZE,
733 g_param_spec_int ("window-size", "Window size",
734 "The size of the window used to calculate rate and offset", 2, 1024,
735 DEFAULT_WINDOW_SIZE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
736 g_object_class_install_property (gobject_class, PROP_WINDOW_THRESHOLD,
737 g_param_spec_int ("window-threshold", "Window threshold",
738 "The threshold to start calculating rate and offset", 2, 1024,
739 DEFAULT_WINDOW_THRESHOLD,
740 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
741 g_object_class_install_property (gobject_class, PROP_TIMEOUT,
742 g_param_spec_uint64 ("timeout", "Timeout",
743 "The amount of time, in nanoseconds, to sample master and slave clocks",
744 0, G_MAXUINT64, DEFAULT_TIMEOUT,
745 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
750 * @synced: if the clock is synced now
752 * Signaled on clocks with GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC set once
753 * the clock is synchronized, or when it completely lost synchronization.
754 * This signal will not be emitted on clocks without the flag.
756 * This signal will be emitted from an arbitrary thread, most likely not
757 * the application's main thread.
761 gst_clock_signals[SIGNAL_SYNCED] =
762 g_signal_new ("synced", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
764 g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_BOOLEAN);
768 gst_clock_init (GstClock * clock)
770 GstClockPrivate *priv;
772 clock->priv = priv = gst_clock_get_instance_private (clock);
776 priv->internal_calibration = 0;
777 priv->external_calibration = 0;
778 priv->rate_numerator = 1;
779 priv->rate_denominator = 1;
781 g_mutex_init (&priv->slave_lock);
782 g_cond_init (&priv->sync_cond);
783 priv->window_size = DEFAULT_WINDOW_SIZE;
784 priv->window_threshold = DEFAULT_WINDOW_THRESHOLD;
785 priv->filling = TRUE;
786 priv->time_index = 0;
787 priv->timeout = DEFAULT_TIMEOUT;
788 priv->times = g_new0 (GstClockTime, 4 * priv->window_size);
789 priv->times_temp = priv->times + 2 * priv->window_size;
793 gst_clock_dispose (GObject * object)
795 GstClock *clock = GST_CLOCK (object);
798 GST_OBJECT_LOCK (clock);
799 master_p = &clock->priv->master;
800 gst_object_replace ((GstObject **) master_p, NULL);
801 GST_OBJECT_UNLOCK (clock);
803 G_OBJECT_CLASS (parent_class)->dispose (object);
807 gst_clock_finalize (GObject * object)
809 GstClock *clock = GST_CLOCK (object);
811 GST_CLOCK_SLAVE_LOCK (clock);
812 if (clock->priv->clockid) {
813 gst_clock_id_unschedule (clock->priv->clockid);
814 gst_clock_id_unref (clock->priv->clockid);
815 clock->priv->clockid = NULL;
817 g_free (clock->priv->times);
818 clock->priv->times = NULL;
819 clock->priv->times_temp = NULL;
820 GST_CLOCK_SLAVE_UNLOCK (clock);
822 g_mutex_clear (&clock->priv->slave_lock);
823 g_cond_clear (&clock->priv->sync_cond);
825 G_OBJECT_CLASS (parent_class)->finalize (object);
829 * gst_clock_set_resolution:
830 * @clock: a #GstClock
831 * @resolution: The resolution to set
833 * Set the accuracy of the clock. Some clocks have the possibility to operate
834 * with different accuracy at the expense of more resource usage. There is
835 * normally no need to change the default resolution of a clock. The resolution
836 * of a clock can only be changed if the clock has the
837 * #GST_CLOCK_FLAG_CAN_SET_RESOLUTION flag set.
839 * Returns: the new resolution of the clock.
842 gst_clock_set_resolution (GstClock * clock, GstClockTime resolution)
844 GstClockPrivate *priv;
845 GstClockClass *cclass;
847 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
848 g_return_val_if_fail (resolution != 0, 0);
850 cclass = GST_CLOCK_GET_CLASS (clock);
853 if (cclass->change_resolution)
855 cclass->change_resolution (clock, priv->resolution, resolution);
857 return priv->resolution;
861 * gst_clock_get_resolution:
862 * @clock: a #GstClock
864 * Get the accuracy of the clock. The accuracy of the clock is the granularity
865 * of the values returned by gst_clock_get_time().
867 * Returns: the resolution of the clock in units of #GstClockTime.
872 gst_clock_get_resolution (GstClock * clock)
874 GstClockClass *cclass;
876 g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
878 cclass = GST_CLOCK_GET_CLASS (clock);
880 if (cclass->get_resolution)
881 return cclass->get_resolution (clock);
886 /* FIXME 2.0: Remove clock parameter below */
888 * gst_clock_adjust_with_calibration:
889 * @clock: (allow-none): a #GstClock to use
890 * @internal_target: a clock time
891 * @cinternal: a reference internal time
892 * @cexternal: a reference external time
893 * @cnum: the numerator of the rate of the clock relative to its
895 * @cdenom: the denominator of the rate of the clock
897 * Converts the given @internal_target clock time to the external time,
898 * using the passed calibration parameters. This function performs the
899 * same calculation as gst_clock_adjust_unlocked() when called using the
900 * current calibration parameters, but doesn't ensure a monotonically
901 * increasing result as gst_clock_adjust_unlocked() does.
903 * Note: The @clock parameter is unused and can be NULL
905 * Returns: the converted time of the clock.
910 gst_clock_adjust_with_calibration (GstClock * clock,
911 GstClockTime internal_target, GstClockTime cinternal,
912 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
916 /* avoid divide by 0 */
917 if (G_UNLIKELY (cdenom == 0))
920 /* The formula is (internal - cinternal) * cnum / cdenom + cexternal
922 * Since we do math on unsigned 64-bit ints we have to special case for
923 * internal < cinternal to get the sign right. this case is not very common,
926 if (G_LIKELY (internal_target >= cinternal)) {
927 ret = internal_target - cinternal;
928 ret = gst_util_uint64_scale (ret, cnum, cdenom);
931 ret = cinternal - internal_target;
932 ret = gst_util_uint64_scale (ret, cnum, cdenom);
934 if (G_LIKELY (cexternal > ret))
935 ret = cexternal - ret;
944 * gst_clock_adjust_unlocked:
945 * @clock: a #GstClock to use
946 * @internal: a clock time
948 * Converts the given @internal clock time to the external time, adjusting for the
949 * rate and reference time set with gst_clock_set_calibration() and making sure
950 * that the returned time is increasing. This function should be called with the
951 * clock's OBJECT_LOCK held and is mainly used by clock subclasses.
953 * This function is the reverse of gst_clock_unadjust_unlocked().
955 * Returns: the converted time of the clock.
958 gst_clock_adjust_unlocked (GstClock * clock, GstClockTime internal)
960 GstClockTime ret, cinternal, cexternal, cnum, cdenom;
961 GstClockPrivate *priv = clock->priv;
963 /* get calibration values for readability */
964 cinternal = priv->internal_calibration;
965 cexternal = priv->external_calibration;
966 cnum = priv->rate_numerator;
967 cdenom = priv->rate_denominator;
970 gst_clock_adjust_with_calibration (clock, internal, cinternal, cexternal,
973 /* make sure the time is increasing */
974 priv->last_time = MAX (ret, priv->last_time);
976 return priv->last_time;
979 /* FIXME 2.0: Remove clock parameter below */
981 * gst_clock_unadjust_with_calibration:
982 * @clock: (allow-none): a #GstClock to use
983 * @external_target: a clock time
984 * @cinternal: a reference internal time
985 * @cexternal: a reference external time
986 * @cnum: the numerator of the rate of the clock relative to its
988 * @cdenom: the denominator of the rate of the clock
990 * Converts the given @external_target clock time to the internal time,
991 * using the passed calibration parameters. This function performs the
992 * same calculation as gst_clock_unadjust_unlocked() when called using the
993 * current calibration parameters.
995 * Note: The @clock parameter is unused and can be NULL
997 * Returns: the converted time of the clock.
1002 gst_clock_unadjust_with_calibration (GstClock * clock,
1003 GstClockTime external_target, GstClockTime cinternal,
1004 GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
1008 /* avoid divide by 0 */
1009 if (G_UNLIKELY (cnum == 0))
1012 /* The formula is (external - cexternal) * cdenom / cnum + cinternal */
1013 if (G_LIKELY (external_target >= cexternal)) {
1014 ret = external_target - cexternal;
1015 ret = gst_util_uint64_scale (ret, cdenom, cnum);
1018 ret = cexternal - external_target;
1019 ret = gst_util_uint64_scale (ret, cdenom, cnum);
1020 if (G_LIKELY (cinternal > ret))
1021 ret = cinternal - ret;
1030 * gst_clock_unadjust_unlocked:
1031 * @clock: a #GstClock to use
1032 * @external: an external clock time
1034 * Converts the given @external clock time to the internal time of @clock,
1035 * using the rate and reference time set with gst_clock_set_calibration().
1036 * This function should be called with the clock's OBJECT_LOCK held and
1037 * is mainly used by clock subclasses.
1039 * This function is the reverse of gst_clock_adjust_unlocked().
1041 * Returns: the internal time of the clock corresponding to @external.
1044 gst_clock_unadjust_unlocked (GstClock * clock, GstClockTime external)
1046 GstClockTime cinternal, cexternal, cnum, cdenom;
1047 GstClockPrivate *priv = clock->priv;
1049 /* get calibration values for readability */
1050 cinternal = priv->internal_calibration;
1051 cexternal = priv->external_calibration;
1052 cnum = priv->rate_numerator;
1053 cdenom = priv->rate_denominator;
1055 return gst_clock_unadjust_with_calibration (clock, external, cinternal,
1056 cexternal, cnum, cdenom);
1060 * gst_clock_get_internal_time:
1061 * @clock: a #GstClock to query
1063 * Gets the current internal time of the given clock. The time is returned
1064 * unadjusted for the offset and the rate.
1066 * Returns: the internal time of the clock. Or GST_CLOCK_TIME_NONE when
1067 * given invalid input.
1072 gst_clock_get_internal_time (GstClock * clock)
1075 GstClockClass *cclass;
1077 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1079 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (clock,
1080 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC) && !clock->priv->synced))
1081 GST_CAT_WARNING_OBJECT (GST_CAT_CLOCK, clock,
1082 "clock is not synchronized yet");
1084 cclass = GST_CLOCK_GET_CLASS (clock);
1086 if (G_UNLIKELY (cclass->get_internal_time == NULL))
1089 ret = cclass->get_internal_time (clock);
1091 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "internal time %" GST_TIME_FORMAT,
1092 GST_TIME_ARGS (ret));
1099 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1100 "internal time not supported, return 0");
1101 return G_GINT64_CONSTANT (0);
1106 * gst_clock_get_time:
1107 * @clock: a #GstClock to query
1109 * Gets the current time of the given clock. The time is always
1110 * monotonically increasing and adjusted according to the current
1113 * Returns: the time of the clock. Or GST_CLOCK_TIME_NONE when
1114 * given invalid input.
1119 gst_clock_get_time (GstClock * clock)
1124 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1127 /* reget the internal time when we retry to get the most current
1129 ret = gst_clock_get_internal_time (clock);
1131 seq = read_seqbegin (clock);
1132 /* this will scale for rate and offset */
1133 ret = gst_clock_adjust_unlocked (clock, ret);
1134 } while (read_seqretry (clock, seq));
1136 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "adjusted time %" GST_TIME_FORMAT,
1137 GST_TIME_ARGS (ret));
1143 * gst_clock_set_calibration:
1144 * @clock: a #GstClock to calibrate
1145 * @internal: a reference internal time
1146 * @external: a reference external time
1147 * @rate_num: the numerator of the rate of the clock relative to its
1149 * @rate_denom: the denominator of the rate of the clock
1151 * Adjusts the rate and time of @clock. A rate of 1/1 is the normal speed of
1152 * the clock. Values bigger than 1/1 make the clock go faster.
1154 * @internal and @external are calibration parameters that arrange that
1155 * gst_clock_get_time() should have been @external at internal time @internal.
1156 * This internal time should not be in the future; that is, it should be less
1157 * than the value of gst_clock_get_internal_time() when this function is called.
1159 * Subsequent calls to gst_clock_get_time() will return clock times computed as
1163 * time = (internal_time - internal) * rate_num / rate_denom + external
1166 * This formula is implemented in gst_clock_adjust_unlocked(). Of course, it
1167 * tries to do the integer arithmetic as precisely as possible.
1169 * Note that gst_clock_get_time() always returns increasing values so when you
1170 * move the clock backwards, gst_clock_get_time() will report the previous value
1171 * until the clock catches up.
1176 gst_clock_set_calibration (GstClock * clock, GstClockTime internal, GstClockTime
1177 external, GstClockTime rate_num, GstClockTime rate_denom)
1179 GstClockPrivate *priv;
1181 g_return_if_fail (GST_IS_CLOCK (clock));
1182 g_return_if_fail (rate_num != GST_CLOCK_TIME_NONE);
1183 g_return_if_fail (rate_denom > 0 && rate_denom != GST_CLOCK_TIME_NONE);
1187 write_seqlock (clock);
1188 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1189 "internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT " %"
1190 G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT " = %f", GST_TIME_ARGS (internal),
1191 GST_TIME_ARGS (external), rate_num, rate_denom,
1192 gst_guint64_to_gdouble (rate_num) / gst_guint64_to_gdouble (rate_denom));
1194 priv->internal_calibration = internal;
1195 priv->external_calibration = external;
1196 priv->rate_numerator = rate_num;
1197 priv->rate_denominator = rate_denom;
1198 write_sequnlock (clock);
1202 * gst_clock_get_calibration:
1203 * @clock: a #GstClock
1204 * @internal: (out) (allow-none): a location to store the internal time
1205 * @external: (out) (allow-none): a location to store the external time
1206 * @rate_num: (out) (allow-none): a location to store the rate numerator
1207 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1209 * Gets the internal rate and reference time of @clock. See
1210 * gst_clock_set_calibration() for more information.
1212 * @internal, @external, @rate_num, and @rate_denom can be left %NULL if the
1213 * caller is not interested in the values.
1218 gst_clock_get_calibration (GstClock * clock, GstClockTime * internal,
1219 GstClockTime * external, GstClockTime * rate_num, GstClockTime * rate_denom)
1222 GstClockPrivate *priv;
1224 g_return_if_fail (GST_IS_CLOCK (clock));
1229 seq = read_seqbegin (clock);
1231 *rate_num = priv->rate_numerator;
1233 *rate_denom = priv->rate_denominator;
1235 *external = priv->external_calibration;
1237 *internal = priv->internal_calibration;
1238 } while (read_seqretry (clock, seq));
1241 /* will be called repeatedly to sample the master and slave clock
1242 * to recalibrate the clock */
1244 gst_clock_slave_callback (GstClock * master, GstClockTime time,
1245 GstClockID id, GstClock * clock)
1247 GstClockTime stime, mtime;
1250 if (!gst_clock_is_synced (clock)) {
1251 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1252 "Slave clock is not synced yet");
1256 stime = gst_clock_get_internal_time (clock);
1257 mtime = gst_clock_get_time (master);
1259 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1260 "master %" GST_TIME_FORMAT ", slave %" GST_TIME_FORMAT,
1261 GST_TIME_ARGS (mtime), GST_TIME_ARGS (stime));
1263 gst_clock_add_observation (clock, stime, mtime, &r_squared);
1265 /* FIXME, we can use the r_squared value to adjust the timeout
1266 * value of the clockid */
1272 * gst_clock_set_master:
1273 * @clock: a #GstClock
1274 * @master: (allow-none): a master #GstClock
1276 * Set @master as the master clock for @clock. @clock will be automatically
1277 * calibrated so that gst_clock_get_time() reports the same time as the
1280 * A clock provider that slaves its clock to a master can get the current
1281 * calibration values with gst_clock_get_calibration().
1283 * @master can be %NULL in which case @clock will not be slaved anymore. It will
1284 * however keep reporting its time adjusted with the last configured rate
1287 * Returns: %TRUE if the clock is capable of being slaved to a master clock.
1288 * Trying to set a master on a clock without the
1289 * #GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return %FALSE.
1294 gst_clock_set_master (GstClock * clock, GstClock * master)
1296 GstClock **master_p;
1297 GstClockPrivate *priv;
1299 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1300 g_return_val_if_fail (master != clock, FALSE);
1302 GST_OBJECT_LOCK (clock);
1303 /* we always allow setting the master to NULL */
1304 if (master && !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER))
1306 if (master && !gst_clock_is_synced (master))
1307 goto master_not_synced;
1309 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1310 "slaving %p to master clock %p", clock, master);
1311 GST_OBJECT_UNLOCK (clock);
1315 GST_CLOCK_SLAVE_LOCK (clock);
1316 if (priv->clockid) {
1317 gst_clock_id_unschedule (priv->clockid);
1318 gst_clock_id_unref (priv->clockid);
1319 priv->clockid = NULL;
1322 priv->filling = TRUE;
1323 priv->time_index = 0;
1324 /* use the master periodic id to schedule sampling and
1325 * clock calibration. */
1326 priv->clockid = gst_clock_new_periodic_id (master,
1327 gst_clock_get_time (master), priv->timeout);
1328 gst_clock_id_wait_async (priv->clockid,
1329 (GstClockCallback) gst_clock_slave_callback,
1330 gst_object_ref (clock), (GDestroyNotify) gst_object_unref);
1332 GST_CLOCK_SLAVE_UNLOCK (clock);
1334 GST_OBJECT_LOCK (clock);
1335 master_p = &priv->master;
1336 gst_object_replace ((GstObject **) master_p, (GstObject *) master);
1337 GST_OBJECT_UNLOCK (clock);
1344 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
1345 "cannot be slaved to a master clock");
1346 GST_OBJECT_UNLOCK (clock);
1352 GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, master,
1353 "master clock is not synced yet");
1354 GST_OBJECT_UNLOCK (clock);
1360 * gst_clock_get_master:
1361 * @clock: a #GstClock
1363 * Get the master clock that @clock is slaved to or %NULL when the clock is
1364 * not slaved to any master clock.
1366 * Returns: (transfer full) (nullable): a master #GstClock or %NULL
1367 * when this clock is not slaved to a master clock. Unref after
1373 gst_clock_get_master (GstClock * clock)
1375 GstClock *result = NULL;
1376 GstClockPrivate *priv;
1378 g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
1382 GST_OBJECT_LOCK (clock);
1384 result = gst_object_ref (priv->master);
1385 GST_OBJECT_UNLOCK (clock);
1391 * gst_clock_id_get_clock:
1392 * @id: a #GstClockID
1394 * This function returns the underlying clock.
1396 * Returns: (transfer full) (nullable): a #GstClock or %NULL when the
1397 * underlying clock has been freed. Unref after usage.
1404 gst_clock_id_get_clock (GstClockID id)
1406 GstClockEntry *entry;
1408 g_return_val_if_fail (id != NULL, NULL);
1410 entry = (GstClockEntry *) id;
1411 return g_weak_ref_get (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry));
1415 * gst_clock_id_uses_clock:
1416 * @id: a #GstClockID to check
1417 * @clock: a #GstClock to compare against
1419 * This function returns whether @id uses @clock as the underlying clock.
1420 * @clock can be NULL, in which case the return value indicates whether
1421 * the underlying clock has been freed. If this is the case, the @id is
1422 * no longer usable and should be freed.
1424 * Returns: whether the clock @id uses the same underlying #GstClock @clock.
1431 gst_clock_id_uses_clock (GstClockID id, GstClock * clock)
1433 GstClockEntry *entry;
1434 GstClock *entry_clock;
1435 gboolean ret = FALSE;
1437 g_return_val_if_fail (id != NULL, FALSE);
1438 g_return_val_if_fail (clock != NULL, FALSE);
1440 entry = (GstClockEntry *) id;
1441 entry_clock = g_weak_ref_get (GST_CLOCK_ENTRY_CLOCK_WEAK_REF (entry));
1442 if (entry_clock == clock)
1445 if (G_LIKELY (entry_clock != NULL))
1446 gst_object_unref (entry_clock);
1453 * gst_clock_add_observation:
1454 * @clock: a #GstClock
1455 * @slave: a time on the slave
1456 * @master: a time on the master
1457 * @r_squared: (out): a pointer to hold the result
1459 * The time @master of the master clock and the time @slave of the slave
1460 * clock are added to the list of observations. If enough observations
1461 * are available, a linear regression algorithm is run on the
1462 * observations and @clock is recalibrated.
1464 * If this functions returns %TRUE, @r_squared will contain the
1465 * correlation coefficient of the interpolation. A value of 1.0
1466 * means a perfect regression was performed. This value can
1467 * be used to control the sampling frequency of the master and slave
1470 * Returns: %TRUE if enough observations were added to run the
1471 * regression algorithm.
1476 gst_clock_add_observation (GstClock * clock, GstClockTime slave,
1477 GstClockTime master, gdouble * r_squared)
1479 GstClockTime m_num, m_denom, b, xbase;
1481 if (!gst_clock_add_observation_unapplied (clock, slave, master, r_squared,
1482 &xbase, &b, &m_num, &m_denom))
1485 /* if we have a valid regression, adjust the clock */
1486 gst_clock_set_calibration (clock, xbase, b, m_num, m_denom);
1492 * gst_clock_add_observation_unapplied:
1493 * @clock: a #GstClock
1494 * @slave: a time on the slave
1495 * @master: a time on the master
1496 * @r_squared: (out): a pointer to hold the result
1497 * @internal: (out) (allow-none): a location to store the internal time
1498 * @external: (out) (allow-none): a location to store the external time
1499 * @rate_num: (out) (allow-none): a location to store the rate numerator
1500 * @rate_denom: (out) (allow-none): a location to store the rate denominator
1502 * Add a clock observation to the internal slaving algorithm the same as
1503 * gst_clock_add_observation(), and return the result of the master clock
1504 * estimation, without updating the internal calibration.
1506 * The caller can then take the results and call gst_clock_set_calibration()
1507 * with the values, or some modified version of them.
1512 gst_clock_add_observation_unapplied (GstClock * clock, GstClockTime slave,
1513 GstClockTime master, gdouble * r_squared,
1514 GstClockTime * internal, GstClockTime * external,
1515 GstClockTime * rate_num, GstClockTime * rate_denom)
1517 GstClockTime m_num, m_denom, b, xbase;
1518 GstClockPrivate *priv;
1521 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1522 g_return_val_if_fail (r_squared != NULL, FALSE);
1526 GST_CLOCK_SLAVE_LOCK (clock);
1528 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1529 "adding observation slave %" GST_TIME_FORMAT ", master %" GST_TIME_FORMAT,
1530 GST_TIME_ARGS (slave), GST_TIME_ARGS (master));
1532 priv->times[(2 * priv->time_index)] = slave;
1533 priv->times[(2 * priv->time_index) + 1] = master;
1536 if (G_UNLIKELY (priv->time_index == priv->window_size)) {
1537 priv->filling = FALSE;
1538 priv->time_index = 0;
1541 if (G_UNLIKELY (priv->filling && priv->time_index < priv->window_threshold))
1544 n = priv->filling ? priv->time_index : priv->window_size;
1545 if (!gst_calculate_linear_regression (priv->times, priv->times_temp, n,
1546 &m_num, &m_denom, &b, &xbase, r_squared))
1549 GST_CLOCK_SLAVE_UNLOCK (clock);
1551 GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
1552 "adjusting clock to m=%" G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT ", b=%"
1553 G_GUINT64_FORMAT " (rsquared=%g)", m_num, m_denom, b, *r_squared);
1562 *rate_denom = m_denom;
1568 GST_CLOCK_SLAVE_UNLOCK (clock);
1573 /* no valid regression has been done, ignore the result then */
1574 GST_CLOCK_SLAVE_UNLOCK (clock);
1580 * gst_clock_set_timeout:
1581 * @clock: a #GstClock
1582 * @timeout: a timeout
1584 * Set the amount of time, in nanoseconds, to sample master and slave
1588 gst_clock_set_timeout (GstClock * clock, GstClockTime timeout)
1590 g_return_if_fail (GST_IS_CLOCK (clock));
1592 GST_CLOCK_SLAVE_LOCK (clock);
1593 clock->priv->timeout = timeout;
1594 GST_CLOCK_SLAVE_UNLOCK (clock);
1598 * gst_clock_get_timeout:
1599 * @clock: a #GstClock
1601 * Get the amount of time that master and slave clocks are sampled.
1603 * Returns: the interval between samples.
1606 gst_clock_get_timeout (GstClock * clock)
1608 GstClockTime result;
1610 g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
1612 GST_CLOCK_SLAVE_LOCK (clock);
1613 result = clock->priv->timeout;
1614 GST_CLOCK_SLAVE_UNLOCK (clock);
1620 gst_clock_set_property (GObject * object, guint prop_id,
1621 const GValue * value, GParamSpec * pspec)
1624 GstClockPrivate *priv;
1626 clock = GST_CLOCK (object);
1630 case PROP_WINDOW_SIZE:
1631 GST_CLOCK_SLAVE_LOCK (clock);
1632 priv->window_size = g_value_get_int (value);
1633 priv->window_threshold = MIN (priv->window_threshold, priv->window_size);
1634 priv->times = g_renew (GstClockTime, priv->times, 4 * priv->window_size);
1635 priv->times_temp = priv->times + 2 * priv->window_size;
1636 /* restart calibration */
1637 priv->filling = TRUE;
1638 priv->time_index = 0;
1639 GST_CLOCK_SLAVE_UNLOCK (clock);
1641 case PROP_WINDOW_THRESHOLD:
1642 GST_CLOCK_SLAVE_LOCK (clock);
1643 priv->window_threshold = MIN (g_value_get_int (value), priv->window_size);
1644 GST_CLOCK_SLAVE_UNLOCK (clock);
1647 gst_clock_set_timeout (clock, g_value_get_uint64 (value));
1650 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1656 gst_clock_get_property (GObject * object, guint prop_id,
1657 GValue * value, GParamSpec * pspec)
1660 GstClockPrivate *priv;
1662 clock = GST_CLOCK (object);
1666 case PROP_WINDOW_SIZE:
1667 GST_CLOCK_SLAVE_LOCK (clock);
1668 g_value_set_int (value, priv->window_size);
1669 GST_CLOCK_SLAVE_UNLOCK (clock);
1671 case PROP_WINDOW_THRESHOLD:
1672 GST_CLOCK_SLAVE_LOCK (clock);
1673 g_value_set_int (value, priv->window_threshold);
1674 GST_CLOCK_SLAVE_UNLOCK (clock);
1677 g_value_set_uint64 (value, gst_clock_get_timeout (clock));
1680 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1687 * gst_clock_wait_for_sync:
1688 * @clock: a GstClock
1689 * @timeout: timeout for waiting or %GST_CLOCK_TIME_NONE
1691 * Waits until @clock is synced for reporting the current time. If @timeout
1692 * is %GST_CLOCK_TIME_NONE it will wait forever, otherwise it will time out
1693 * after @timeout nanoseconds.
1695 * For asynchronous waiting, the GstClock::synced signal can be used.
1697 * This returns immediately with TRUE if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1698 * is not set on the clock, or if the clock is already synced.
1700 * Returns: %TRUE if waiting was successful, or %FALSE on timeout
1705 gst_clock_wait_for_sync (GstClock * clock, GstClockTime timeout)
1707 gboolean timed_out = FALSE;
1709 g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
1711 GST_OBJECT_LOCK (clock);
1712 if (!GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1713 || clock->priv->synced) {
1714 GST_OBJECT_UNLOCK (clock);
1718 if (timeout != GST_CLOCK_TIME_NONE) {
1719 gint64 end_time = g_get_monotonic_time () + gst_util_uint64_scale (timeout,
1720 G_TIME_SPAN_SECOND, GST_SECOND);
1722 while (!clock->priv->synced && !timed_out) {
1724 !g_cond_wait_until (&clock->priv->sync_cond,
1725 GST_OBJECT_GET_LOCK (clock), end_time);
1729 while (!clock->priv->synced) {
1730 g_cond_wait (&clock->priv->sync_cond, GST_OBJECT_GET_LOCK (clock));
1733 GST_OBJECT_UNLOCK (clock);
1739 * gst_clock_is_synced:
1740 * @clock: a GstClock
1742 * Checks if the clock is currently synced.
1744 * This returns if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC is not set on the clock.
1746 * Returns: %TRUE if the clock is currently synced
1751 gst_clock_is_synced (GstClock * clock)
1753 g_return_val_if_fail (GST_IS_CLOCK (clock), TRUE);
1755 return !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
1756 || clock->priv->synced;
1760 * gst_clock_set_synced:
1761 * @clock: a GstClock
1762 * @synced: if the clock is synced
1764 * Sets @clock to synced and emits the GstClock::synced signal, and wakes up any
1765 * thread waiting in gst_clock_wait_for_sync().
1767 * This function must only be called if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
1768 * is set on the clock, and is intended to be called by subclasses only.
1773 gst_clock_set_synced (GstClock * clock, gboolean synced)
1775 g_return_if_fail (GST_IS_CLOCK (clock));
1776 g_return_if_fail (GST_OBJECT_FLAG_IS_SET (clock,
1777 GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC));
1779 GST_OBJECT_LOCK (clock);
1780 if (clock->priv->synced != ! !synced) {
1781 clock->priv->synced = ! !synced;
1782 g_cond_signal (&clock->priv->sync_cond);
1783 GST_OBJECT_UNLOCK (clock);
1784 g_signal_emit (clock, gst_clock_signals[SIGNAL_SYNCED], 0, ! !synced);
1786 GST_OBJECT_UNLOCK (clock);