gstreamer/gst/gstclock.c
Wim Taymans 29e2850eff Documentation updates
Original commit message from CVS:
Documentation updates
2002-12-14 13:02:16 +00:00

662 lines
15 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstclock.c: Clock subsystem for maintaining time sync
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <sys/time.h>
/* #define GST_DEBUG_ENABLED */
#include "gst_private.h"
#include "gstclock.h"
#include "gstlog.h"
#include "gstmemchunk.h"
enum {
ARG_0,
ARG_STATS,
};
#define CLASS(clock) GST_CLOCK_CLASS (G_OBJECT_GET_CLASS (clock))
static GstMemChunk *_gst_clock_entries_chunk;
static void gst_clock_class_init (GstClockClass *klass);
static void gst_clock_init (GstClock *clock);
static void gst_clock_set_property (GObject *object, guint prop_id,
const GValue *value, GParamSpec *pspec);
static void gst_clock_get_property (GObject *object, guint prop_id,
GValue *value, GParamSpec * pspec);
static void gst_clock_update_stats (GstClock *clock);
static GstObjectClass *parent_class = NULL;
/* static guint gst_clock_signals[LAST_SIGNAL] = { 0 }; */
static GMutex *_gst_clock_mutex;
static GCond *_gst_clock_cond;
static inline GstClockID
gst_clock_entry_new (GstClock *clock, GstClockTime time,
GstClockTime interval, GstClockEntryType type)
{
GstClockEntry *entry;
entry = gst_mem_chunk_alloc (_gst_clock_entries_chunk);
entry->clock = clock;
entry->time = time;
entry->interval = time;
entry->type = type;
entry->status = GST_CLOCK_ENTRY_OK;
return (GstClockID) entry;
}
/**
* gst_clock_new_single_shot_id
* @clock: The clockid to get a single shot notification from
* @time: the requested time
*
* Get an ID from the given clock to trigger a single shot
* notification at the requested time.
*
* Returns: An id that can be used to request the time notification.
*/
GstClockID
gst_clock_new_single_shot_id (GstClock *clock, GstClockTime time)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
return gst_clock_entry_new (clock,
time,
GST_CLOCK_TIME_NONE,
GST_CLOCK_ENTRY_SINGLE);
}
/**
* gst_clock_new_periodic_id
* @clock: The clockid to get a periodic notification id from
* @start_time: the requested start time
* @interval: the requested interval
*
* Get an ID from the given clock to trigger a periodic notification.
* The periodeic notifications will be start at time start_time and
* will then be fired with the given interval.
*
* Returns: An id that can be used to request the time notification.
*/
GstClockID
gst_clock_new_periodic_id (GstClock *clock, GstClockTime start_time,
GstClockTime interval)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
g_return_val_if_fail (start_time != GST_CLOCK_TIME_NONE, NULL);
g_return_val_if_fail (interval != 0, NULL);
return gst_clock_entry_new (clock,
start_time,
interval,
GST_CLOCK_ENTRY_PERIODIC);
}
/**
* gst_clock_id_get_time
* @id: The clockid to query
*
* Get the time of the clock ID
*
* Returns: the time of the given clock id
*/
GstClockTime
gst_clock_id_get_time (GstClockID id)
{
g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
return GST_CLOCK_ENTRY_TIME ((GstClockEntry *)id);
}
/**
* gst_clock_id_wait
* @id: The clockid to wait on
* @jitter: A pointer that will contain the jitter
*
* Perform a blocking wait on the given ID. The jitter arg can be
* NULL
*
* Returns: the result of the blocking wait.
*/
GstClockReturn
gst_clock_id_wait (GstClockID id, GstClockTimeDiff *jitter)
{
GstClockEntry *entry;
GstClock *clock;
GstClockReturn res = GST_CLOCK_UNSUPPORTED;
GstClockTime requested;
g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
entry = (GstClockEntry *) id;
requested = GST_CLOCK_ENTRY_TIME (entry);
if (requested == GST_CLOCK_TIME_NONE) {
res = GST_CLOCK_TIMEOUT;
goto done;
}
clock = GST_CLOCK_ENTRY_CLOCK (entry);
if (CLASS (clock)->wait) {
GstClockTime now;
do {
res = CLASS (clock)->wait (clock, entry);
}
while (res == GST_CLOCK_ENTRY_RESTART);
if (jitter) {
now = gst_clock_get_time (clock);
*jitter = now - requested;
}
if (clock->stats) {
gst_clock_update_stats (clock);
}
}
done:
if (entry->type == GST_CLOCK_ENTRY_SINGLE) {
gst_clock_id_free (id);
}
return res;
}
/**
* gst_clock_id_wait_async:
* @id: a #GstClockID to wait on
* @func: The callback function
* @user_data: User data passed in the calback
*
* Register a callback on the given clockid with the given
* function and user_data.
*
* Returns: the result of the non blocking wait.
*/
GstClockReturn
gst_clock_id_wait_async (GstClockID id,
GstClockCallback func, gpointer user_data)
{
GstClockEntry *entry;
GstClock *clock;
GstClockReturn res = GST_CLOCK_UNSUPPORTED;
g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
entry = (GstClockEntry *) id;
clock = entry->clock;
if (GST_CLOCK_ENTRY_TIME (entry) == GST_CLOCK_TIME_NONE) {
(func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
return GST_CLOCK_TIMEOUT;
}
if (CLASS (clock)->wait_async) {
res = CLASS (clock)->wait_async (clock, entry, func, user_data);
}
return res;
}
/**
* gst_clock_id_unschedule:
* @id: The id to unschedule
*
* Cancel an outstanding async notification request with the given ID.
*/
void
gst_clock_id_unschedule (GstClockID id)
{
GstClockEntry *entry;
GstClock *clock;
g_return_if_fail (id != NULL);
entry = (GstClockEntry *) id;
clock = entry->clock;
if (CLASS (clock)->unschedule)
CLASS (clock)->unschedule (clock, entry);
}
/**
* gst_clock_id_free:
* @id: The clockid to free
*
* Free the resources held by the given id
*/
void
gst_clock_id_free (GstClockID id)
{
g_return_if_fail (id != NULL);
gst_mem_chunk_free (_gst_clock_entries_chunk, id);
}
/**
* gst_clock_id_unlock:
* @id: The clockid to unlock
*
* Unlock the givan ClockID.
*/
void
gst_clock_id_unlock (GstClockID id)
{
GstClockEntry *entry;
GstClock *clock;
g_return_if_fail (id != NULL);
entry = (GstClockEntry *) id;
clock = entry->clock;
if (CLASS (clock)->unlock)
CLASS (clock)->unlock (clock, entry);
}
/**
* GstClock abstract base class implementation
*/
GType
gst_clock_get_type (void)
{
static GType clock_type = 0;
if (!clock_type) {
static const GTypeInfo clock_info = {
sizeof (GstClockClass),
NULL,
NULL,
(GClassInitFunc) gst_clock_class_init,
NULL,
NULL,
sizeof (GstClock),
4,
(GInstanceInitFunc) gst_clock_init,
NULL
};
clock_type = g_type_register_static (GST_TYPE_OBJECT, "GstClock",
&clock_info, G_TYPE_FLAG_ABSTRACT);
}
return clock_type;
}
static void
gst_clock_class_init (GstClockClass *klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
gobject_class = (GObjectClass*) klass;
gstobject_class = (GstObjectClass*) klass;
parent_class = g_type_class_ref (GST_TYPE_OBJECT);
if (!g_thread_supported ())
g_thread_init (NULL);
_gst_clock_entries_chunk = gst_mem_chunk_new ("GstClockEntries",
sizeof (GstClockEntry), sizeof (GstClockEntry) * 32,
G_ALLOC_AND_FREE);
_gst_clock_mutex = g_mutex_new ();
_gst_clock_cond = g_cond_new ();
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_clock_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_clock_get_property);
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_STATS,
g_param_spec_boolean ("stats", "Stats", "Enable clock stats",
FALSE, G_PARAM_READWRITE));
}
static void
gst_clock_init (GstClock *clock)
{
clock->speed = 1.0;
clock->active = FALSE;
clock->start_time = 0;
clock->last_time = 0;
clock->entries = NULL;
clock->flags = 0;
clock->stats = FALSE;
clock->active_mutex = g_mutex_new ();
clock->active_cond = g_cond_new ();
}
/**
* gst_clock_set_speed
* @clock: a #GstClock to modify
* @speed: the speed to set on the clock
*
* Sets the speed on the given clock. 1.0 is the default
* speed.
*
* Returns: the new speed of the clock.
*/
gdouble
gst_clock_set_speed (GstClock *clock, gdouble speed)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), 0.0);
if (CLASS (clock)->change_speed)
clock->speed = CLASS (clock)->change_speed (clock, clock->speed, speed);
return clock->speed;
}
/**
* gst_clock_get_speed
* @clock: a #GstClock to query
*
* Gets the speed of the given clock.
*
* Returns: the speed of the clock.
*/
gdouble
gst_clock_get_speed (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), 0.0);
return clock->speed;
}
/**
* gst_clock_set_resolution
* @clock: The clock set the resolution on
* @resolution: The resolution to set
*
* Set the accuracy of the clock.
*
* Returns: the new resolution of the clock.
*/
guint64
gst_clock_set_resolution (GstClock *clock, guint64 resolution)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), 0LL);
g_return_val_if_fail (resolution != 0, 0LL);
if (CLASS (clock)->change_resolution)
clock->resolution = CLASS (clock)->change_resolution (clock, clock->resolution, resolution);
return clock->resolution;
}
/**
* gst_clock_get_resolution
* @clock: The clock get the resolution of
*
* Get the accuracy of the clock.
*
* Returns: the resolution of the clock in microseconds.
*/
guint64
gst_clock_get_resolution (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), 0LL);
if (CLASS (clock)->get_resolution)
return CLASS (clock)->get_resolution (clock);
return 1LL;
}
/**
* gst_clock_set_active
* @clock: a #GstClock to set state of
* @active: flag indicating if the clock should be activated (TRUE) or deactivated
*
* Activates or deactivates the clock based on the active parameter.
* As soon as the clock is activated, the time will start ticking.
*/
void
gst_clock_set_active (GstClock *clock, gboolean active)
{
GstClockTime time = 0LL;
g_return_if_fail (GST_IS_CLOCK (clock));
clock->active = active;
if (CLASS (clock)->get_internal_time) {
time = CLASS (clock)->get_internal_time (clock);
}
GST_LOCK (clock);
if (active) {
clock->start_time = time - clock->last_time;
clock->accept_discont = TRUE;
}
else {
clock->last_time = time - clock->start_time;
clock->accept_discont = FALSE;
}
GST_UNLOCK (clock);
g_mutex_lock (clock->active_mutex);
g_cond_broadcast (clock->active_cond);
g_mutex_unlock (clock->active_mutex);
}
/**
* gst_clock_is_active
* @clock: a #GstClock to query
*
* Checks if the given clock is active.
*
* Returns: TRUE if the clock is active.
*/
gboolean
gst_clock_is_active (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
return clock->active;
}
/**
* gst_clock_reset
* @clock: a #GstClock to reset
*
* Reset the clock to time 0.
*/
void
gst_clock_reset (GstClock *clock)
{
GstClockTime time = 0LL;
g_return_if_fail (GST_IS_CLOCK (clock));
if (CLASS (clock)->get_internal_time) {
time = CLASS (clock)->get_internal_time (clock);
}
GST_LOCK (clock);
clock->active = FALSE;
clock->start_time = time;
clock->last_time = 0LL;
GST_UNLOCK (clock);
}
/**
* gst_clock_handle_discont
* @clock: a #GstClock to notify of the discontinuity
* @time: The new time
*
* Notifies the clock of a discontinuity in time.
*
* Returns: TRUE if the clock was updated. It is possible that
* the clock was not updated by this call because only the first
* discontinuitity in the pipeline is honoured.
*/
gboolean
gst_clock_handle_discont (GstClock *clock, guint64 time)
{
GstClockTime itime = 0LL;
GST_DEBUG (GST_CAT_CLOCK, "clock discont %" G_GUINT64_FORMAT
" %" G_GUINT64_FORMAT " %d",
time, clock->start_time, clock->accept_discont);
if (time == GST_CLOCK_TIME_NONE)
return TRUE;
GST_LOCK (clock);
if (clock->accept_discont) {
if (CLASS (clock)->get_internal_time) {
itime = CLASS (clock)->get_internal_time (clock);
}
}
else {
GST_UNLOCK (clock);
GST_DEBUG (GST_CAT_CLOCK, "clock discont refused %" G_GUINT64_FORMAT
" %" G_GUINT64_FORMAT,
time, clock->start_time);
return FALSE;
}
clock->start_time = itime - time;
clock->last_time = time;
clock->accept_discont = FALSE;
GST_UNLOCK (clock);
GST_DEBUG (GST_CAT_CLOCK, "new time %" G_GUINT64_FORMAT,
gst_clock_get_time (clock));
g_mutex_lock (clock->active_mutex);
g_cond_broadcast (clock->active_cond);
g_mutex_unlock (clock->active_mutex);
return TRUE;
}
/**
* gst_clock_get_time
* @clock: a #GstClock to query
*
* Gets the current time of the given clock. The time is always
* monotonically increasing.
*
* Returns: the time of the clock.
*/
GstClockTime
gst_clock_get_time (GstClock *clock)
{
GstClockTime ret = 0LL;
g_return_val_if_fail (GST_IS_CLOCK (clock), 0LL);
if (!clock->active) {
/* clock is not activen return previous time */
ret = clock->last_time;
}
else {
if (CLASS (clock)->get_internal_time) {
ret = CLASS (clock)->get_internal_time (clock) - clock->start_time;
}
/* make sure the time is increasing, else return last_time */
if ((gint64) ret < (gint64) clock->last_time) {
ret = clock->last_time;
}
else {
clock->last_time = ret;
}
}
return ret;
}
/**
* gst_clock_get_next_id
* @clock: The clock to query
*
* Get the clockid of the next event.
*
* Returns: a clockid or NULL is no event is pending.
*/
GstClockID
gst_clock_get_next_id (GstClock *clock)
{
GstClockEntry *entry = NULL;
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
GST_LOCK (clock);
if (clock->entries)
entry = GST_CLOCK_ENTRY (clock->entries->data);
GST_UNLOCK (clock);
return (GstClockID *) entry;
}
static void
gst_clock_update_stats (GstClock *clock)
{
}
static void
gst_clock_set_property (GObject *object, guint prop_id,
const GValue *value, GParamSpec *pspec)
{
GstClock *clock;
clock = GST_CLOCK (object);
switch (prop_id) {
case ARG_STATS:
clock->stats = g_value_get_boolean (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;
clock = GST_CLOCK (object);
switch (prop_id) {
case ARG_STATS:
g_value_set_boolean (value, clock->stats);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}