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Rename gst_clock_id_wait_async_full() to gst_clock_id_wait_async() and remove the old gst_clock_id_wait_async() version.
1517 lines
44 KiB
C
1517 lines
44 KiB
C
/* GStreamer
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* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
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* 2000 Wim Taymans <wtay@chello.be>
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* 2004 Wim Taymans <wim@fluendo.com>
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*
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* gstclock.c: Clock subsystem for maintaining time sync
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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/**
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* SECTION:gstclock
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* @short_description: Abstract class for global clocks
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* @see_also: #GstSystemClock, #GstPipeline
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*
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* GStreamer uses a global clock to synchronize the plugins in a pipeline.
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* Different clock implementations are possible by implementing this abstract
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* base class or, more conveniently, by subclassing #GstSystemClock.
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*
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* The #GstClock returns a monotonically increasing time with the method
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* gst_clock_get_time(). Its accuracy and base time depend on the specific
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* clock implementation but time is always expressed in nanoseconds. Since the
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* baseline of the clock is undefined, the clock time returned is not
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* meaningful in itself, what matters are the deltas between two clock times.
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* The time returned by a clock is called the absolute time.
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*
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* The pipeline uses the clock to calculate the running time. Usually all
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* renderers synchronize to the global clock using the buffer timestamps, the
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* newsegment events and the element's base time, see #GstPipeline.
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*
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* A clock implementation can support periodic and single shot clock
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* notifications both synchronous and asynchronous.
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*
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* One first needs to create a #GstClockID for the periodic or single shot
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* notification using gst_clock_new_single_shot_id() or
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* gst_clock_new_periodic_id().
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*
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* To perform a blocking wait for the specific time of the #GstClockID use the
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* gst_clock_id_wait(). To receive a callback when the specific time is reached
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* in the clock use gst_clock_id_wait_async(). Both these calls can be
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* interrupted with the gst_clock_id_unschedule() call. If the blocking wait is
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* unscheduled a return value of #GST_CLOCK_UNSCHEDULED is returned.
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*
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* Periodic callbacks scheduled async will be repeatedly called automatically
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* until it is unscheduled. To schedule a sync periodic callback,
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* gst_clock_id_wait() should be called repeatedly.
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*
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* The async callbacks can happen from any thread, either provided by the core
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* or from a streaming thread. The application should be prepared for this.
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*
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* A #GstClockID that has been unscheduled cannot be used again for any wait
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* operation, a new #GstClockID should be created and the old unscheduled one
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* should be destroyed with gst_clock_id_unref().
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*
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* It is possible to perform a blocking wait on the same #GstClockID from
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* multiple threads. However, registering the same #GstClockID for multiple
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* async notifications is not possible, the callback will only be called for
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* the thread registering the entry last.
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*
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* None of the wait operations unref the #GstClockID, the owner is responsible
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* for unreffing the ids itself. This holds for both periodic and single shot
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* notifications. The reason being that the owner of the #GstClockID has to
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* keep a handle to the #GstClockID to unblock the wait on FLUSHING events or
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* state changes and if the entry would be unreffed automatically, the handle
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* might become invalid without any notification.
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*
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* These clock operations do not operate on the running time, so the callbacks
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* will also occur when not in PLAYING state as if the clock just keeps on
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* running. Some clocks however do not progress when the element that provided
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* the clock is not PLAYING.
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*
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* When a clock has the #GST_CLOCK_FLAG_CAN_SET_MASTER flag set, it can be
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* slaved to another #GstClock with the gst_clock_set_master(). The clock will
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* then automatically be synchronized to this master clock by repeatedly
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* sampling the master clock and the slave clock and recalibrating the slave
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* clock with gst_clock_set_calibration(). This feature is mostly useful for
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* plugins that have an internal clock but must operate with another clock
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* selected by the #GstPipeline. They can track the offset and rate difference
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* of their internal clock relative to the master clock by using the
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* gst_clock_get_calibration() function.
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*
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* The master/slave synchronisation can be tuned with the #GstClock:timeout,
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* #GstClock:window-size and #GstClock:window-threshold properties.
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* The #GstClock:timeout property defines the interval to sample the master
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* clock and run the calibration functions. #GstClock:window-size defines the
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* number of samples to use when calibrating and #GstClock:window-threshold
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* defines the minimum number of samples before the calibration is performed.
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*
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* Last reviewed on 2012-03-28 (0.11.3)
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*/
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#include "gst_private.h"
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#include <time.h>
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#include "gstclock.h"
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#include "gstinfo.h"
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#include "gstutils.h"
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#include "glib-compat-private.h"
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#ifndef GST_DISABLE_TRACE
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/* #define GST_WITH_ALLOC_TRACE */
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#include "gsttrace.h"
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static GstAllocTrace *_gst_clock_entry_trace;
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#endif
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/* #define DEBUGGING_ENABLED */
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#define DEFAULT_WINDOW_SIZE 32
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#define DEFAULT_WINDOW_THRESHOLD 4
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#define DEFAULT_TIMEOUT GST_SECOND / 10
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enum
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{
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PROP_0,
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PROP_WINDOW_SIZE,
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PROP_WINDOW_THRESHOLD,
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PROP_TIMEOUT
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};
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#define GST_CLOCK_SLAVE_LOCK(clock) g_mutex_lock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
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#define GST_CLOCK_SLAVE_UNLOCK(clock) g_mutex_unlock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
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struct _GstClockPrivate
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{
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GMutex slave_lock; /* order: SLAVE_LOCK, OBJECT_LOCK */
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/* with LOCK */
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GstClockTime internal_calibration;
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GstClockTime external_calibration;
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GstClockTime rate_numerator;
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GstClockTime rate_denominator;
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GstClockTime last_time;
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/* with LOCK */
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GstClockTime resolution;
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/* for master/slave clocks */
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GstClock *master;
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/* with SLAVE_LOCK */
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gboolean filling;
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gint window_size;
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gint window_threshold;
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gint time_index;
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GstClockTime timeout;
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GstClockTime *times;
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GstClockID clockid;
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gint pre_count;
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gint post_count;
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};
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/* seqlocks */
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#define read_seqbegin(clock) \
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g_atomic_int_get (&clock->priv->post_count);
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static inline gboolean
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read_seqretry (GstClock * clock, gint seq)
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{
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/* no retry if the seqnum did not change */
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if (G_LIKELY (seq == g_atomic_int_get (&clock->priv->pre_count)))
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return FALSE;
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/* wait for the writer to finish and retry */
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GST_OBJECT_LOCK (clock);
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GST_OBJECT_UNLOCK (clock);
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return TRUE;
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}
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#define write_seqlock(clock) \
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G_STMT_START { \
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GST_OBJECT_LOCK (clock); \
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g_atomic_int_inc (&clock->priv->pre_count); \
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} G_STMT_END;
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#define write_sequnlock(clock) \
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G_STMT_START { \
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g_atomic_int_inc (&clock->priv->post_count); \
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GST_OBJECT_UNLOCK (clock); \
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} G_STMT_END;
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static void gst_clock_dispose (GObject * object);
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static void gst_clock_finalize (GObject * object);
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static void gst_clock_set_property (GObject * object, guint prop_id,
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const GValue * value, GParamSpec * pspec);
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static void gst_clock_get_property (GObject * object, guint prop_id,
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GValue * value, GParamSpec * pspec);
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/* static guint gst_clock_signals[LAST_SIGNAL] = { 0 }; */
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static GstClockID
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gst_clock_entry_new (GstClock * clock, GstClockTime time,
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GstClockTime interval, GstClockEntryType type)
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{
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GstClockEntry *entry;
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entry = g_slice_new (GstClockEntry);
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#ifndef GST_DISABLE_TRACE
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_gst_alloc_trace_new (_gst_clock_entry_trace, entry);
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#endif
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GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
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"created entry %p, time %" GST_TIME_FORMAT, entry, GST_TIME_ARGS (time));
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entry->refcount = 1;
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entry->clock = clock;
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entry->type = type;
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entry->time = time;
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entry->interval = interval;
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entry->status = GST_CLOCK_OK;
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entry->func = NULL;
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entry->user_data = NULL;
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entry->destroy_data = NULL;
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entry->unscheduled = FALSE;
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entry->woken_up = FALSE;
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return (GstClockID) entry;
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}
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/* WARNING : Does not modify the refcount
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* WARNING : Do not use if a pending clock operation is happening on that entry */
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static gboolean
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gst_clock_entry_reinit (GstClock * clock, GstClockEntry * entry,
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GstClockTime time, GstClockTime interval, GstClockEntryType type)
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{
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g_return_val_if_fail (entry->status != GST_CLOCK_BUSY, FALSE);
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g_return_val_if_fail (entry->clock == clock, FALSE);
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entry->type = type;
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entry->time = time;
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entry->interval = interval;
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entry->status = GST_CLOCK_OK;
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entry->unscheduled = FALSE;
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entry->woken_up = FALSE;
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return TRUE;
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}
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/**
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* gst_clock_single_shot_id_reinit:
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* @clock: a #GstClock
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* @id: a #GstClockID
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* @time: The requested time.
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*
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* Reinitializes the provided single shot @id to the provided time. Does not
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* modify the reference count.
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*
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* Returns: %TRUE if the GstClockID could be reinitialized to the provided
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* @time, else %FALSE.
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*
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* Since: 0.10.32
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*/
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gboolean
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gst_clock_single_shot_id_reinit (GstClock * clock, GstClockID id,
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GstClockTime time)
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{
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return gst_clock_entry_reinit (clock, (GstClockEntry *) id, time,
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GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
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}
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/**
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* gst_clock_periodic_id_reinit:
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* @clock: a #GstClock
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* @id: a #GstClockID
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* @start_time: the requested start time
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* @interval: the requested interval
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*
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* Reinitializes the provided periodic @id to the provided start time and
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* interval. Does not modify the reference count.
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*
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* Returns: %TRUE if the GstClockID could be reinitialized to the provided
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* @time, else %FALSE.
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*
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* Since: 0.10.33
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*
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*/
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gboolean
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gst_clock_periodic_id_reinit (GstClock * clock, GstClockID id,
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GstClockTime start_time, GstClockTime interval)
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{
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return gst_clock_entry_reinit (clock, (GstClockEntry *) id, start_time,
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interval, GST_CLOCK_ENTRY_PERIODIC);
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}
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/**
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* gst_clock_id_ref:
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* @id: The #GstClockID to ref
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*
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* Increase the refcount of given @id.
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*
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* Returns: (transfer full): The same #GstClockID with increased refcount.
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*
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* MT safe.
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*/
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GstClockID
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gst_clock_id_ref (GstClockID id)
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{
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g_return_val_if_fail (id != NULL, NULL);
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g_atomic_int_inc (&((GstClockEntry *) id)->refcount);
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return id;
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}
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static void
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_gst_clock_id_free (GstClockID id)
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{
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GstClockEntry *entry;
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g_return_if_fail (id != NULL);
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GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);
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entry = (GstClockEntry *) id;
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if (entry->destroy_data)
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entry->destroy_data (entry->user_data);
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#ifndef GST_DISABLE_TRACE
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_gst_alloc_trace_free (_gst_clock_entry_trace, id);
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#endif
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g_slice_free (GstClockEntry, id);
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}
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/**
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* gst_clock_id_unref:
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* @id: (transfer full): The #GstClockID to unref
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*
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* Unref given @id. When the refcount reaches 0 the
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* #GstClockID will be freed.
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*
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* MT safe.
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*/
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void
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gst_clock_id_unref (GstClockID id)
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{
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gint zero;
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g_return_if_fail (id != NULL);
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zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);
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/* if we ended up with the refcount at zero, free the id */
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if (zero) {
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_gst_clock_id_free (id);
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}
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}
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/**
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* gst_clock_new_single_shot_id:
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* @clock: The #GstClockID to get a single shot notification from
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* @time: the requested time
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*
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* Get a #GstClockID from @clock to trigger a single shot
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* notification at the requested time. The single shot id should be
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* unreffed after usage.
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*
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* Free-function: gst_clock_id_unref
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*
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* Returns: (transfer full): a #GstClockID that can be used to request the
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* time notification.
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*
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* MT safe.
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*/
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GstClockID
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gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)
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{
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g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
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return gst_clock_entry_new (clock,
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time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
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}
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/**
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* gst_clock_new_periodic_id:
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* @clock: The #GstClockID to get a periodic notification id from
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* @start_time: the requested start time
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* @interval: the requested interval
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*
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* Get an ID from @clock to trigger a periodic notification.
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* The periodic notifications will start at time @start_time and
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* will then be fired with the given @interval. @id should be unreffed
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* after usage.
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*
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* Free-function: gst_clock_id_unref
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*
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* Returns: (transfer full): a #GstClockID that can be used to request the
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* time notification.
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*
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* MT safe.
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*/
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GstClockID
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gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,
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GstClockTime interval)
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{
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g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
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g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);
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g_return_val_if_fail (interval != 0, NULL);
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g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);
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return gst_clock_entry_new (clock,
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start_time, interval, GST_CLOCK_ENTRY_PERIODIC);
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}
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/**
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* gst_clock_id_compare_func:
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* @id1: A #GstClockID
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* @id2: A #GstClockID to compare with
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*
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* Compares the two #GstClockID instances. This function can be used
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* as a GCompareFunc when sorting ids.
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*
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* Returns: negative value if a < b; zero if a = b; positive value if a > b
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*
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* MT safe.
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*/
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gint
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gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)
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{
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GstClockEntry *entry1, *entry2;
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entry1 = (GstClockEntry *) id1;
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entry2 = (GstClockEntry *) id2;
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if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {
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return 1;
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}
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if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {
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return -1;
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}
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return 0;
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}
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/**
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* gst_clock_id_get_time:
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* @id: The #GstClockID to query
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*
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* Get the time of the clock ID
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*
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* Returns: the time of the given clock id.
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*
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* MT safe.
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*/
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GstClockTime
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gst_clock_id_get_time (GstClockID id)
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{
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g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
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return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);
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}
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/**
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* gst_clock_id_wait:
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* @id: The #GstClockID to wait on
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* @jitter: (out) (allow-none): a pointer that will contain the jitter,
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* can be %NULL.
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*
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* Perform a blocking wait on @id.
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* @id should have been created with gst_clock_new_single_shot_id()
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* or gst_clock_new_periodic_id() and should not have been unscheduled
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* with a call to gst_clock_id_unschedule().
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*
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* If the @jitter argument is not %NULL and this function returns #GST_CLOCK_OK
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* or #GST_CLOCK_EARLY, it will contain the difference
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* against the clock and the time of @id when this method was
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* called.
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* Positive values indicate how late @id was relative to the clock
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* (in which case this function will return #GST_CLOCK_EARLY).
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* Negative values indicate how much time was spent waiting on the clock
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* before this function returned.
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*
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* Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned
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* if the current clock time is past the time of @id, #GST_CLOCK_OK if
|
|
* @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was
|
|
* unscheduled with gst_clock_id_unschedule().
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstClockReturn
|
|
gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)
|
|
{
|
|
GstClockEntry *entry;
|
|
GstClock *clock;
|
|
GstClockReturn res;
|
|
GstClockTime requested;
|
|
GstClockClass *cclass;
|
|
|
|
g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
|
|
|
|
entry = (GstClockEntry *) id;
|
|
requested = GST_CLOCK_ENTRY_TIME (entry);
|
|
|
|
clock = GST_CLOCK_ENTRY_CLOCK (entry);
|
|
|
|
/* can't sync on invalid times */
|
|
if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
|
|
goto invalid_time;
|
|
|
|
cclass = GST_CLOCK_GET_CLASS (clock);
|
|
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);
|
|
|
|
/* if we have a wait_jitter function, use that */
|
|
if (G_UNLIKELY (cclass->wait == NULL))
|
|
goto not_supported;
|
|
|
|
res = cclass->wait (clock, entry, jitter);
|
|
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"done waiting entry %p, res: %d", id, res);
|
|
|
|
if (entry->type == GST_CLOCK_ENTRY_PERIODIC)
|
|
entry->time = requested + entry->interval;
|
|
|
|
return res;
|
|
|
|
/* ERRORS */
|
|
invalid_time:
|
|
{
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"invalid time requested, returning _BADTIME");
|
|
return GST_CLOCK_BADTIME;
|
|
}
|
|
not_supported:
|
|
{
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
|
|
return GST_CLOCK_UNSUPPORTED;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_clock_id_wait_async:
|
|
* @id: a #GstClockID to wait on
|
|
* @func: The callback function
|
|
* @user_data: User data passed in the callback
|
|
* @destroy_data: #GDestroyNotify for user_data
|
|
*
|
|
* Register a callback on the given #GstClockID @id with the given
|
|
* function and user_data. When passing a #GstClockID with an invalid
|
|
* time to this function, the callback will be called immediately
|
|
* with a time set to GST_CLOCK_TIME_NONE. The callback will
|
|
* be called when the time of @id has been reached.
|
|
*
|
|
* The callback @func can be invoked from any thread, either provided by the
|
|
* core or from a streaming thread. The application should be prepared for this.
|
|
*
|
|
* Returns: the result of the non blocking wait.
|
|
*
|
|
* MT safe.
|
|
*
|
|
* Since: 0.10.30
|
|
*/
|
|
GstClockReturn
|
|
gst_clock_id_wait_async (GstClockID id,
|
|
GstClockCallback func, gpointer user_data, GDestroyNotify destroy_data)
|
|
{
|
|
GstClockEntry *entry;
|
|
GstClock *clock;
|
|
GstClockReturn res;
|
|
GstClockClass *cclass;
|
|
GstClockTime requested;
|
|
|
|
g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
|
|
g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
|
|
|
|
entry = (GstClockEntry *) id;
|
|
requested = GST_CLOCK_ENTRY_TIME (entry);
|
|
clock = GST_CLOCK_ENTRY_CLOCK (entry);
|
|
|
|
/* can't sync on invalid times */
|
|
if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
|
|
goto invalid_time;
|
|
|
|
cclass = GST_CLOCK_GET_CLASS (clock);
|
|
|
|
if (G_UNLIKELY (cclass->wait_async == NULL))
|
|
goto not_supported;
|
|
|
|
entry->func = func;
|
|
entry->user_data = user_data;
|
|
entry->destroy_data = destroy_data;
|
|
|
|
res = cclass->wait_async (clock, entry);
|
|
|
|
return res;
|
|
|
|
/* ERRORS */
|
|
invalid_time:
|
|
{
|
|
(func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"invalid time requested, returning _BADTIME");
|
|
return GST_CLOCK_BADTIME;
|
|
}
|
|
not_supported:
|
|
{
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
|
|
return GST_CLOCK_UNSUPPORTED;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_clock_id_unschedule:
|
|
* @id: The id to unschedule
|
|
*
|
|
* Cancel an outstanding request with @id. This can either
|
|
* be an outstanding async notification or a pending sync notification.
|
|
* After this call, @id cannot be used anymore to receive sync or
|
|
* async notifications, you need to create a new #GstClockID.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_clock_id_unschedule (GstClockID id)
|
|
{
|
|
GstClockEntry *entry;
|
|
GstClock *clock;
|
|
GstClockClass *cclass;
|
|
|
|
g_return_if_fail (id != NULL);
|
|
|
|
entry = (GstClockEntry *) id;
|
|
clock = entry->clock;
|
|
|
|
cclass = GST_CLOCK_GET_CLASS (clock);
|
|
|
|
if (G_LIKELY (cclass->unschedule))
|
|
cclass->unschedule (clock, entry);
|
|
}
|
|
|
|
|
|
/*
|
|
* GstClock abstract base class implementation
|
|
*/
|
|
#define gst_clock_parent_class parent_class
|
|
G_DEFINE_TYPE (GstClock, gst_clock, GST_TYPE_OBJECT);
|
|
|
|
static void
|
|
gst_clock_class_init (GstClockClass * klass)
|
|
{
|
|
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
|
|
|
|
#ifndef GST_DISABLE_TRACE
|
|
_gst_clock_entry_trace = _gst_alloc_trace_register ("GstClockEntry", -1);
|
|
#endif
|
|
|
|
gobject_class->dispose = gst_clock_dispose;
|
|
gobject_class->finalize = gst_clock_finalize;
|
|
gobject_class->set_property = gst_clock_set_property;
|
|
gobject_class->get_property = gst_clock_get_property;
|
|
|
|
g_object_class_install_property (gobject_class, PROP_WINDOW_SIZE,
|
|
g_param_spec_int ("window-size", "Window size",
|
|
"The size of the window used to calculate rate and offset", 2, 1024,
|
|
DEFAULT_WINDOW_SIZE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
|
|
g_object_class_install_property (gobject_class, PROP_WINDOW_THRESHOLD,
|
|
g_param_spec_int ("window-threshold", "Window threshold",
|
|
"The threshold to start calculating rate and offset", 2, 1024,
|
|
DEFAULT_WINDOW_THRESHOLD,
|
|
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
|
|
g_object_class_install_property (gobject_class, PROP_TIMEOUT,
|
|
g_param_spec_uint64 ("timeout", "Timeout",
|
|
"The amount of time, in nanoseconds, to sample master and slave clocks",
|
|
0, G_MAXUINT64, DEFAULT_TIMEOUT,
|
|
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
|
|
|
|
g_type_class_add_private (klass, sizeof (GstClockPrivate));
|
|
}
|
|
|
|
static void
|
|
gst_clock_init (GstClock * clock)
|
|
{
|
|
GstClockPrivate *priv;
|
|
|
|
clock->priv = priv =
|
|
G_TYPE_INSTANCE_GET_PRIVATE (clock, GST_TYPE_CLOCK, GstClockPrivate);
|
|
|
|
priv->last_time = 0;
|
|
|
|
priv->internal_calibration = 0;
|
|
priv->external_calibration = 0;
|
|
priv->rate_numerator = 1;
|
|
priv->rate_denominator = 1;
|
|
|
|
g_mutex_init (&priv->slave_lock);
|
|
priv->window_size = DEFAULT_WINDOW_SIZE;
|
|
priv->window_threshold = DEFAULT_WINDOW_THRESHOLD;
|
|
priv->filling = TRUE;
|
|
priv->time_index = 0;
|
|
priv->timeout = DEFAULT_TIMEOUT;
|
|
priv->times = g_new0 (GstClockTime, 4 * priv->window_size);
|
|
}
|
|
|
|
static void
|
|
gst_clock_dispose (GObject * object)
|
|
{
|
|
GstClock *clock = GST_CLOCK (object);
|
|
GstClock **master_p;
|
|
|
|
GST_OBJECT_LOCK (clock);
|
|
master_p = &clock->priv->master;
|
|
gst_object_replace ((GstObject **) master_p, NULL);
|
|
GST_OBJECT_UNLOCK (clock);
|
|
|
|
G_OBJECT_CLASS (parent_class)->dispose (object);
|
|
}
|
|
|
|
static void
|
|
gst_clock_finalize (GObject * object)
|
|
{
|
|
GstClock *clock = GST_CLOCK (object);
|
|
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
if (clock->priv->clockid) {
|
|
gst_clock_id_unschedule (clock->priv->clockid);
|
|
gst_clock_id_unref (clock->priv->clockid);
|
|
clock->priv->clockid = NULL;
|
|
}
|
|
g_free (clock->priv->times);
|
|
clock->priv->times = NULL;
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
|
|
g_mutex_clear (&clock->priv->slave_lock);
|
|
|
|
G_OBJECT_CLASS (parent_class)->finalize (object);
|
|
}
|
|
|
|
/**
|
|
* gst_clock_set_resolution:
|
|
* @clock: a #GstClock
|
|
* @resolution: The resolution to set
|
|
*
|
|
* Set the accuracy of the clock. Some clocks have the possibility to operate
|
|
* with different accuracy at the expense of more resource usage. There is
|
|
* normally no need to change the default resolution of a clock. The resolution
|
|
* of a clock can only be changed if the clock has the
|
|
* #GST_CLOCK_FLAG_CAN_SET_RESOLUTION flag set.
|
|
*
|
|
* Returns: the new resolution of the clock.
|
|
*/
|
|
GstClockTime
|
|
gst_clock_set_resolution (GstClock * clock, GstClockTime resolution)
|
|
{
|
|
GstClockPrivate *priv;
|
|
GstClockClass *cclass;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
|
|
g_return_val_if_fail (resolution != 0, 0);
|
|
|
|
cclass = GST_CLOCK_GET_CLASS (clock);
|
|
priv = clock->priv;
|
|
|
|
if (cclass->change_resolution)
|
|
priv->resolution =
|
|
cclass->change_resolution (clock, priv->resolution, resolution);
|
|
|
|
return priv->resolution;
|
|
}
|
|
|
|
/**
|
|
* gst_clock_get_resolution:
|
|
* @clock: a #GstClock
|
|
*
|
|
* Get the accuracy of the clock. The accuracy of the clock is the granularity
|
|
* of the values returned by gst_clock_get_time().
|
|
*
|
|
* Returns: the resolution of the clock in units of #GstClockTime.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstClockTime
|
|
gst_clock_get_resolution (GstClock * clock)
|
|
{
|
|
GstClockClass *cclass;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
|
|
|
|
cclass = GST_CLOCK_GET_CLASS (clock);
|
|
|
|
if (cclass->get_resolution)
|
|
return cclass->get_resolution (clock);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* gst_clock_adjust_unlocked:
|
|
* @clock: a #GstClock to use
|
|
* @internal: a clock time
|
|
*
|
|
* Converts the given @internal clock time to the external time, adjusting for the
|
|
* rate and reference time set with gst_clock_set_calibration() and making sure
|
|
* that the returned time is increasing. This function should be called with the
|
|
* clock's OBJECT_LOCK held and is mainly used by clock subclasses.
|
|
*
|
|
* This function is the reverse of gst_clock_unadjust_unlocked().
|
|
*
|
|
* Returns: the converted time of the clock.
|
|
*/
|
|
GstClockTime
|
|
gst_clock_adjust_unlocked (GstClock * clock, GstClockTime internal)
|
|
{
|
|
GstClockTime ret, cinternal, cexternal, cnum, cdenom;
|
|
GstClockPrivate *priv = clock->priv;
|
|
|
|
/* get calibration values for readability */
|
|
cinternal = priv->internal_calibration;
|
|
cexternal = priv->external_calibration;
|
|
cnum = priv->rate_numerator;
|
|
cdenom = priv->rate_denominator;
|
|
|
|
/* avoid divide by 0 */
|
|
if (G_UNLIKELY (cdenom == 0))
|
|
cnum = cdenom = 1;
|
|
|
|
/* The formula is (internal - cinternal) * cnum / cdenom + cexternal
|
|
*
|
|
* Since we do math on unsigned 64-bit ints we have to special case for
|
|
* internal < cinternal to get the sign right. this case is not very common,
|
|
* though.
|
|
*/
|
|
if (G_LIKELY (internal >= cinternal)) {
|
|
ret = internal - cinternal;
|
|
ret = gst_util_uint64_scale (ret, cnum, cdenom);
|
|
ret += cexternal;
|
|
} else {
|
|
ret = cinternal - internal;
|
|
ret = gst_util_uint64_scale (ret, cnum, cdenom);
|
|
/* clamp to 0 */
|
|
if (G_LIKELY (cexternal > ret))
|
|
ret = cexternal - ret;
|
|
else
|
|
ret = 0;
|
|
}
|
|
|
|
/* make sure the time is increasing */
|
|
priv->last_time = MAX (ret, priv->last_time);
|
|
|
|
return priv->last_time;
|
|
}
|
|
|
|
/**
|
|
* gst_clock_unadjust_unlocked:
|
|
* @clock: a #GstClock to use
|
|
* @external: an external clock time
|
|
*
|
|
* Converts the given @external clock time to the internal time of @clock,
|
|
* using the rate and reference time set with gst_clock_set_calibration().
|
|
* This function should be called with the clock's OBJECT_LOCK held and
|
|
* is mainly used by clock subclasses.
|
|
*
|
|
* This function is the reverse of gst_clock_adjust_unlocked().
|
|
*
|
|
* Returns: the internal time of the clock corresponding to @external.
|
|
*
|
|
* Since: 0.10.13
|
|
*/
|
|
GstClockTime
|
|
gst_clock_unadjust_unlocked (GstClock * clock, GstClockTime external)
|
|
{
|
|
GstClockTime ret, cinternal, cexternal, cnum, cdenom;
|
|
GstClockPrivate *priv = clock->priv;
|
|
|
|
/* get calibration values for readability */
|
|
cinternal = priv->internal_calibration;
|
|
cexternal = priv->external_calibration;
|
|
cnum = priv->rate_numerator;
|
|
cdenom = priv->rate_denominator;
|
|
|
|
/* avoid divide by 0 */
|
|
if (G_UNLIKELY (cnum == 0))
|
|
cnum = cdenom = 1;
|
|
|
|
/* The formula is (external - cexternal) * cdenom / cnum + cinternal */
|
|
if (G_LIKELY (external >= cexternal)) {
|
|
ret = external - cexternal;
|
|
ret = gst_util_uint64_scale (ret, cdenom, cnum);
|
|
ret += cinternal;
|
|
} else {
|
|
ret = cexternal - external;
|
|
ret = gst_util_uint64_scale (ret, cdenom, cnum);
|
|
if (G_LIKELY (cinternal > ret))
|
|
ret = cinternal - ret;
|
|
else
|
|
ret = 0;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* gst_clock_get_internal_time:
|
|
* @clock: a #GstClock to query
|
|
*
|
|
* Gets the current internal time of the given clock. The time is returned
|
|
* unadjusted for the offset and the rate.
|
|
*
|
|
* Returns: the internal time of the clock. Or GST_CLOCK_TIME_NONE when
|
|
* given invalid input.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstClockTime
|
|
gst_clock_get_internal_time (GstClock * clock)
|
|
{
|
|
GstClockTime ret;
|
|
GstClockClass *cclass;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
|
|
|
|
cclass = GST_CLOCK_GET_CLASS (clock);
|
|
|
|
if (G_UNLIKELY (cclass->get_internal_time == NULL))
|
|
goto not_supported;
|
|
|
|
ret = cclass->get_internal_time (clock);
|
|
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "internal time %" GST_TIME_FORMAT,
|
|
GST_TIME_ARGS (ret));
|
|
|
|
return ret;
|
|
|
|
/* ERRORS */
|
|
not_supported:
|
|
{
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"internal time not supported, return 0");
|
|
return G_GINT64_CONSTANT (0);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_clock_get_time:
|
|
* @clock: a #GstClock to query
|
|
*
|
|
* Gets the current time of the given clock. The time is always
|
|
* monotonically increasing and adjusted according to the current
|
|
* offset and rate.
|
|
*
|
|
* Returns: the time of the clock. Or GST_CLOCK_TIME_NONE when
|
|
* given invalid input.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstClockTime
|
|
gst_clock_get_time (GstClock * clock)
|
|
{
|
|
GstClockTime ret;
|
|
gint seq;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
|
|
|
|
do {
|
|
/* reget the internal time when we retry to get the most current
|
|
* timevalue */
|
|
ret = gst_clock_get_internal_time (clock);
|
|
|
|
seq = read_seqbegin (clock);
|
|
/* this will scale for rate and offset */
|
|
ret = gst_clock_adjust_unlocked (clock, ret);
|
|
} while (read_seqretry (clock, seq));
|
|
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "adjusted time %" GST_TIME_FORMAT,
|
|
GST_TIME_ARGS (ret));
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* gst_clock_set_calibration:
|
|
* @clock: a #GstClock to calibrate
|
|
* @internal: a reference internal time
|
|
* @external: a reference external time
|
|
* @rate_num: the numerator of the rate of the clock relative to its
|
|
* internal time
|
|
* @rate_denom: the denominator of the rate of the clock
|
|
*
|
|
* Adjusts the rate and time of @clock. A rate of 1/1 is the normal speed of
|
|
* the clock. Values bigger than 1/1 make the clock go faster.
|
|
*
|
|
* @internal and @external are calibration parameters that arrange that
|
|
* gst_clock_get_time() should have been @external at internal time @internal.
|
|
* This internal time should not be in the future; that is, it should be less
|
|
* than the value of gst_clock_get_internal_time() when this function is called.
|
|
*
|
|
* Subsequent calls to gst_clock_get_time() will return clock times computed as
|
|
* follows:
|
|
*
|
|
* <programlisting>
|
|
* time = (internal_time - internal) * rate_num / rate_denom + external
|
|
* </programlisting>
|
|
*
|
|
* This formula is implemented in gst_clock_adjust_unlocked(). Of course, it
|
|
* tries to do the integer arithmetic as precisely as possible.
|
|
*
|
|
* Note that gst_clock_get_time() always returns increasing values so when you
|
|
* move the clock backwards, gst_clock_get_time() will report the previous value
|
|
* until the clock catches up.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_clock_set_calibration (GstClock * clock, GstClockTime internal, GstClockTime
|
|
external, GstClockTime rate_num, GstClockTime rate_denom)
|
|
{
|
|
GstClockPrivate *priv;
|
|
|
|
g_return_if_fail (GST_IS_CLOCK (clock));
|
|
g_return_if_fail (rate_num != GST_CLOCK_TIME_NONE);
|
|
g_return_if_fail (rate_denom > 0 && rate_denom != GST_CLOCK_TIME_NONE);
|
|
|
|
priv = clock->priv;
|
|
|
|
write_seqlock (clock);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT " %"
|
|
G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT " = %f", GST_TIME_ARGS (internal),
|
|
GST_TIME_ARGS (external), rate_num, rate_denom,
|
|
gst_guint64_to_gdouble (rate_num) / gst_guint64_to_gdouble (rate_denom));
|
|
|
|
priv->internal_calibration = internal;
|
|
priv->external_calibration = external;
|
|
priv->rate_numerator = rate_num;
|
|
priv->rate_denominator = rate_denom;
|
|
write_sequnlock (clock);
|
|
}
|
|
|
|
/**
|
|
* gst_clock_get_calibration:
|
|
* @clock: a #GstClock
|
|
* @internal: (out) (allow-none): a location to store the internal time
|
|
* @external: (out) (allow-none): a location to store the external time
|
|
* @rate_num: (out) (allow-none): a location to store the rate numerator
|
|
* @rate_denom: (out) (allow-none): a location to store the rate denominator
|
|
*
|
|
* Gets the internal rate and reference time of @clock. See
|
|
* gst_clock_set_calibration() for more information.
|
|
*
|
|
* @internal, @external, @rate_num, and @rate_denom can be left %NULL if the
|
|
* caller is not interested in the values.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_clock_get_calibration (GstClock * clock, GstClockTime * internal,
|
|
GstClockTime * external, GstClockTime * rate_num, GstClockTime * rate_denom)
|
|
{
|
|
gint seq;
|
|
GstClockPrivate *priv;
|
|
|
|
g_return_if_fail (GST_IS_CLOCK (clock));
|
|
|
|
priv = clock->priv;
|
|
|
|
do {
|
|
seq = read_seqbegin (clock);
|
|
if (rate_num)
|
|
*rate_num = priv->rate_numerator;
|
|
if (rate_denom)
|
|
*rate_denom = priv->rate_denominator;
|
|
if (external)
|
|
*external = priv->external_calibration;
|
|
if (internal)
|
|
*internal = priv->internal_calibration;
|
|
} while (read_seqretry (clock, seq));
|
|
}
|
|
|
|
/* will be called repeatedly to sample the master and slave clock
|
|
* to recalibrate the clock */
|
|
static gboolean
|
|
gst_clock_slave_callback (GstClock * master, GstClockTime time,
|
|
GstClockID id, GstClock * clock)
|
|
{
|
|
GstClockTime stime, mtime;
|
|
gdouble r_squared;
|
|
|
|
stime = gst_clock_get_internal_time (clock);
|
|
mtime = gst_clock_get_time (master);
|
|
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"master %" GST_TIME_FORMAT ", slave %" GST_TIME_FORMAT,
|
|
GST_TIME_ARGS (mtime), GST_TIME_ARGS (stime));
|
|
|
|
gst_clock_add_observation (clock, stime, mtime, &r_squared);
|
|
|
|
/* FIXME, we can use the r_squared value to adjust the timeout
|
|
* value of the clockid */
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gst_clock_set_master:
|
|
* @clock: a #GstClock
|
|
* @master: (allow-none): a master #GstClock
|
|
*
|
|
* Set @master as the master clock for @clock. @clock will be automatically
|
|
* calibrated so that gst_clock_get_time() reports the same time as the
|
|
* master clock.
|
|
*
|
|
* A clock provider that slaves its clock to a master can get the current
|
|
* calibration values with gst_clock_get_calibration().
|
|
*
|
|
* @master can be %NULL in which case @clock will not be slaved anymore. It will
|
|
* however keep reporting its time adjusted with the last configured rate
|
|
* and time offsets.
|
|
*
|
|
* Returns: %TRUE if the clock is capable of being slaved to a master clock.
|
|
* Trying to set a master on a clock without the
|
|
* #GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return %FALSE.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
gboolean
|
|
gst_clock_set_master (GstClock * clock, GstClock * master)
|
|
{
|
|
GstClock **master_p;
|
|
GstClockPrivate *priv;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
|
|
g_return_val_if_fail (master != clock, FALSE);
|
|
|
|
GST_OBJECT_LOCK (clock);
|
|
/* we always allow setting the master to NULL */
|
|
if (master && !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER))
|
|
goto not_supported;
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"slaving %p to master clock %p", clock, master);
|
|
GST_OBJECT_UNLOCK (clock);
|
|
|
|
priv = clock->priv;
|
|
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
if (priv->clockid) {
|
|
gst_clock_id_unschedule (priv->clockid);
|
|
gst_clock_id_unref (priv->clockid);
|
|
priv->clockid = NULL;
|
|
}
|
|
if (master) {
|
|
priv->filling = TRUE;
|
|
priv->time_index = 0;
|
|
/* use the master periodic id to schedule sampling and
|
|
* clock calibration. */
|
|
priv->clockid = gst_clock_new_periodic_id (master,
|
|
gst_clock_get_time (master), priv->timeout);
|
|
gst_clock_id_wait_async (priv->clockid,
|
|
(GstClockCallback) gst_clock_slave_callback,
|
|
gst_object_ref (clock), (GDestroyNotify) gst_object_unref);
|
|
}
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
|
|
GST_OBJECT_LOCK (clock);
|
|
master_p = &priv->master;
|
|
gst_object_replace ((GstObject **) master_p, (GstObject *) master);
|
|
GST_OBJECT_UNLOCK (clock);
|
|
|
|
return TRUE;
|
|
|
|
/* ERRORS */
|
|
not_supported:
|
|
{
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"cannot be slaved to a master clock");
|
|
GST_OBJECT_UNLOCK (clock);
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_clock_get_master:
|
|
* @clock: a #GstClock
|
|
*
|
|
* Get the master clock that @clock is slaved to or %NULL when the clock is
|
|
* not slaved to any master clock.
|
|
*
|
|
* Returns: (transfer full): a master #GstClock or %NULL when this clock is
|
|
* not slaved to a master clock. Unref after usage.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstClock *
|
|
gst_clock_get_master (GstClock * clock)
|
|
{
|
|
GstClock *result = NULL;
|
|
GstClockPrivate *priv;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
|
|
|
|
priv = clock->priv;
|
|
|
|
GST_OBJECT_LOCK (clock);
|
|
if (priv->master)
|
|
result = gst_object_ref (priv->master);
|
|
GST_OBJECT_UNLOCK (clock);
|
|
|
|
return result;
|
|
}
|
|
|
|
/* http://mathworld.wolfram.com/LeastSquaresFitting.html
|
|
* with SLAVE_LOCK
|
|
*/
|
|
static gboolean
|
|
do_linear_regression (GstClock * clock, GstClockTime * m_num,
|
|
GstClockTime * m_denom, GstClockTime * b, GstClockTime * xbase,
|
|
gdouble * r_squared)
|
|
{
|
|
GstClockTime *newx, *newy;
|
|
GstClockTime xmin, ymin, xbar, ybar, xbar4, ybar4;
|
|
GstClockTimeDiff sxx, sxy, syy;
|
|
GstClockTime *x, *y;
|
|
gint i, j;
|
|
guint n;
|
|
GstClockPrivate *priv;
|
|
|
|
xbar = ybar = sxx = syy = sxy = 0;
|
|
|
|
priv = clock->priv;
|
|
|
|
x = priv->times;
|
|
y = priv->times + 2;
|
|
n = priv->filling ? priv->time_index : priv->window_size;
|
|
|
|
#ifdef DEBUGGING_ENABLED
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "doing regression on:");
|
|
for (i = j = 0; i < n; i++, j += 4)
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
" %" G_GUINT64_FORMAT " %" G_GUINT64_FORMAT, x[j], y[j]);
|
|
#endif
|
|
|
|
xmin = ymin = G_MAXUINT64;
|
|
for (i = j = 0; i < n; i++, j += 4) {
|
|
xmin = MIN (xmin, x[j]);
|
|
ymin = MIN (ymin, y[j]);
|
|
}
|
|
|
|
#ifdef DEBUGGING_ENABLED
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "min x: %" G_GUINT64_FORMAT,
|
|
xmin);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "min y: %" G_GUINT64_FORMAT,
|
|
ymin);
|
|
#endif
|
|
|
|
newx = priv->times + 1;
|
|
newy = priv->times + 3;
|
|
|
|
/* strip off unnecessary bits of precision */
|
|
for (i = j = 0; i < n; i++, j += 4) {
|
|
newx[j] = x[j] - xmin;
|
|
newy[j] = y[j] - ymin;
|
|
}
|
|
|
|
#ifdef DEBUGGING_ENABLED
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "reduced numbers:");
|
|
for (i = j = 0; i < n; i++, j += 4)
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
|
|
" %" G_GUINT64_FORMAT " %" G_GUINT64_FORMAT, newx[j], newy[j]);
|
|
#endif
|
|
|
|
/* have to do this precisely otherwise the results are pretty much useless.
|
|
* should guarantee that none of these accumulators can overflow */
|
|
|
|
/* quantities on the order of 1e10 -> 30 bits; window size a max of 2^10, so
|
|
this addition could end up around 2^40 or so -- ample headroom */
|
|
for (i = j = 0; i < n; i++, j += 4) {
|
|
xbar += newx[j];
|
|
ybar += newy[j];
|
|
}
|
|
xbar /= n;
|
|
ybar /= n;
|
|
|
|
#ifdef DEBUGGING_ENABLED
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, " xbar = %" G_GUINT64_FORMAT,
|
|
xbar);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, " ybar = %" G_GUINT64_FORMAT,
|
|
ybar);
|
|
#endif
|
|
|
|
/* multiplying directly would give quantities on the order of 1e20 -> 60 bits;
|
|
times the window size that's 70 which is too much. Instead we (1) subtract
|
|
off the xbar*ybar in the loop instead of after, to avoid accumulation; (2)
|
|
shift off 4 bits from each multiplicand, giving an expected ceiling of 52
|
|
bits, which should be enough. Need to check the incoming range and domain
|
|
to ensure this is an appropriate loss of precision though. */
|
|
xbar4 = xbar >> 4;
|
|
ybar4 = ybar >> 4;
|
|
for (i = j = 0; i < n; i++, j += 4) {
|
|
GstClockTime newx4, newy4;
|
|
|
|
newx4 = newx[j] >> 4;
|
|
newy4 = newy[j] >> 4;
|
|
|
|
sxx += newx4 * newx4 - xbar4 * xbar4;
|
|
syy += newy4 * newy4 - ybar4 * ybar4;
|
|
sxy += newx4 * newy4 - xbar4 * ybar4;
|
|
}
|
|
|
|
if (G_UNLIKELY (sxx == 0))
|
|
goto invalid;
|
|
|
|
*m_num = sxy;
|
|
*m_denom = sxx;
|
|
*xbase = xmin;
|
|
*b = (ybar + ymin) - gst_util_uint64_scale (xbar, *m_num, *m_denom);
|
|
*r_squared = ((double) sxy * (double) sxy) / ((double) sxx * (double) syy);
|
|
|
|
#ifdef DEBUGGING_ENABLED
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, " m = %g",
|
|
((double) *m_num) / *m_denom);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, " b = %" G_GUINT64_FORMAT,
|
|
*b);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, " xbase = %" G_GUINT64_FORMAT,
|
|
*xbase);
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, " r2 = %g", *r_squared);
|
|
#endif
|
|
|
|
return TRUE;
|
|
|
|
invalid:
|
|
{
|
|
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "sxx == 0, regression failed");
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_clock_add_observation:
|
|
* @clock: a #GstClock
|
|
* @slave: a time on the slave
|
|
* @master: a time on the master
|
|
* @r_squared: (out): a pointer to hold the result
|
|
*
|
|
* The time @master of the master clock and the time @slave of the slave
|
|
* clock are added to the list of observations. If enough observations
|
|
* are available, a linear regression algorithm is run on the
|
|
* observations and @clock is recalibrated.
|
|
*
|
|
* If this functions returns %TRUE, @r_squared will contain the
|
|
* correlation coefficient of the interpolation. A value of 1.0
|
|
* means a perfect regression was performed. This value can
|
|
* be used to control the sampling frequency of the master and slave
|
|
* clocks.
|
|
*
|
|
* Returns: %TRUE if enough observations were added to run the
|
|
* regression algorithm.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
gboolean
|
|
gst_clock_add_observation (GstClock * clock, GstClockTime slave,
|
|
GstClockTime master, gdouble * r_squared)
|
|
{
|
|
GstClockTime m_num, m_denom, b, xbase;
|
|
GstClockPrivate *priv;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
|
|
g_return_val_if_fail (r_squared != NULL, FALSE);
|
|
|
|
priv = clock->priv;
|
|
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
|
|
GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"adding observation slave %" GST_TIME_FORMAT ", master %" GST_TIME_FORMAT,
|
|
GST_TIME_ARGS (slave), GST_TIME_ARGS (master));
|
|
|
|
priv->times[(4 * priv->time_index)] = slave;
|
|
priv->times[(4 * priv->time_index) + 2] = master;
|
|
|
|
priv->time_index++;
|
|
if (G_UNLIKELY (priv->time_index == priv->window_size)) {
|
|
priv->filling = FALSE;
|
|
priv->time_index = 0;
|
|
}
|
|
|
|
if (G_UNLIKELY (priv->filling && priv->time_index < priv->window_threshold))
|
|
goto filling;
|
|
|
|
if (!do_linear_regression (clock, &m_num, &m_denom, &b, &xbase, r_squared))
|
|
goto invalid;
|
|
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
|
|
GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
|
|
"adjusting clock to m=%" G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT ", b=%"
|
|
G_GUINT64_FORMAT " (rsquared=%g)", m_num, m_denom, b, *r_squared);
|
|
|
|
/* if we have a valid regression, adjust the clock */
|
|
gst_clock_set_calibration (clock, xbase, b, m_num, m_denom);
|
|
|
|
return TRUE;
|
|
|
|
filling:
|
|
{
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
return FALSE;
|
|
}
|
|
invalid:
|
|
{
|
|
/* no valid regression has been done, ignore the result then */
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
return TRUE;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_clock_set_timeout:
|
|
* @clock: a #GstClock
|
|
* @timeout: a timeout
|
|
*
|
|
* Set the amount of time, in nanoseconds, to sample master and slave
|
|
* clocks
|
|
*/
|
|
void
|
|
gst_clock_set_timeout (GstClock * clock, GstClockTime timeout)
|
|
{
|
|
g_return_if_fail (GST_IS_CLOCK (clock));
|
|
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
clock->priv->timeout = timeout;
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
}
|
|
|
|
/**
|
|
* gst_clock_get_timeout:
|
|
* @clock: a #GstClock
|
|
*
|
|
* Get the amount of time that master and slave clocks are sampled.
|
|
*
|
|
* Returns: the interval between samples.
|
|
*/
|
|
GstClockTime
|
|
gst_clock_get_timeout (GstClock * clock)
|
|
{
|
|
GstClockTime result;
|
|
|
|
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
|
|
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
result = clock->priv->timeout;
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
|
|
return result;
|
|
}
|
|
|
|
static void
|
|
gst_clock_set_property (GObject * object, guint prop_id,
|
|
const GValue * value, GParamSpec * pspec)
|
|
{
|
|
GstClock *clock;
|
|
GstClockPrivate *priv;
|
|
|
|
clock = GST_CLOCK (object);
|
|
priv = clock->priv;
|
|
|
|
switch (prop_id) {
|
|
case PROP_WINDOW_SIZE:
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
priv->window_size = g_value_get_int (value);
|
|
priv->window_threshold = MIN (priv->window_threshold, priv->window_size);
|
|
priv->times = g_renew (GstClockTime, priv->times, 4 * priv->window_size);
|
|
/* restart calibration */
|
|
priv->filling = TRUE;
|
|
priv->time_index = 0;
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
break;
|
|
case PROP_WINDOW_THRESHOLD:
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
priv->window_threshold = MIN (g_value_get_int (value), priv->window_size);
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
break;
|
|
case PROP_TIMEOUT:
|
|
gst_clock_set_timeout (clock, g_value_get_uint64 (value));
|
|
break;
|
|
default:
|
|
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void
|
|
gst_clock_get_property (GObject * object, guint prop_id,
|
|
GValue * value, GParamSpec * pspec)
|
|
{
|
|
GstClock *clock;
|
|
GstClockPrivate *priv;
|
|
|
|
clock = GST_CLOCK (object);
|
|
priv = clock->priv;
|
|
|
|
switch (prop_id) {
|
|
case PROP_WINDOW_SIZE:
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
g_value_set_int (value, priv->window_size);
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
break;
|
|
case PROP_WINDOW_THRESHOLD:
|
|
GST_CLOCK_SLAVE_LOCK (clock);
|
|
g_value_set_int (value, priv->window_threshold);
|
|
GST_CLOCK_SLAVE_UNLOCK (clock);
|
|
break;
|
|
case PROP_TIMEOUT:
|
|
g_value_set_uint64 (value, gst_clock_get_timeout (clock));
|
|
break;
|
|
default:
|
|
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
|
|
break;
|
|
}
|
|
}
|