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 PROP_STATS:
GST_OBJECT_LOCK (clock);
g_value_set_boolean (value, clock->stats);
GST_OBJECT_UNLOCK (clock);
break;
case PROP_WINDOW_SIZE:
GST_CLOCK_SLAVE_LOCK (clock);
g_value_set_int (value, clock->window_size);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_WINDOW_THRESHOLD:
GST_CLOCK_SLAVE_LOCK (clock);
g_value_set_int (value, clock->window_threshold);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_TIMEOUT:
GST_CLOCK_SLAVE_LOCK (clock);
g_value_set_uint64 (value, clock->timeout);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
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;
}
}
/**
* 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_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;
}
}
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 PROP_STATS:
GST_OBJECT_LOCK (clock);
clock->stats = g_value_get_boolean (value);
GST_OBJECT_UNLOCK (clock);
g_object_notify (object, "stats");
break;
case PROP_WINDOW_SIZE:
GST_CLOCK_SLAVE_LOCK (clock);
clock->window_size = g_value_get_int (value);
clock->window_threshold =
MIN (clock->window_threshold, clock->window_size);
clock->times =
g_renew (GstClockTime, clock->times, 4 * clock->window_size);
/* restart calibration */
clock->filling = TRUE;
clock->time_index = 0;
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_WINDOW_THRESHOLD:
GST_CLOCK_SLAVE_LOCK (clock);
clock->window_threshold =
MIN (g_value_get_int (value), clock->window_size);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_TIMEOUT:
GST_CLOCK_SLAVE_LOCK (clock);
clock->timeout = g_value_get_uint64 (value);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* 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_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_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);
}
static void
gst_net_client_clock_observe_times (GstNetClientClock * self,
GstClockTime local_1, GstClockTime remote, GstClockTime local_2)
{
GstClockTime local_avg;
gdouble r_squared;
GstClock *clock;
if (local_2 < local_1)
goto bogus_observation;
local_avg = (local_2 + local_1) / 2;
clock = GST_CLOCK_CAST (self);
gst_clock_add_observation (GST_CLOCK (self), local_avg, remote, &r_squared);
GST_CLOCK_SLAVE_LOCK (self);
if (clock->filling) {
self->current_timeout = 0;
} else {
/* geto formula */
self->current_timeout =
(1e-3 / (1 - MIN (r_squared, 0.99999))) * GST_SECOND;
self->current_timeout = MIN (self->current_timeout, clock->timeout);
}
GST_CLOCK_SLAVE_UNLOCK (clock);
return;
bogus_observation:
{
GST_WARNING_OBJECT (self, "time packet receive time < send time (%"
GST_TIME_FORMAT " < %" GST_TIME_FORMAT ")", GST_TIME_ARGS (local_1),
GST_TIME_ARGS (local_2));
return;
}
}
/**
* gst_clock_add_observation_unapplied:
* @clock: a #GstClock
* @slave: a time on the slave
* @master: a time on the master
* @r_squared: (out): a pointer to hold the result
* @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
*
* Add a clock observation to the internal slaving algorithm the same as
* gst_clock_add_observation(), and return the result of the master clock
* estimation, without updating the internal calibration.
*
* The caller can then take the results and call gst_clock_set_calibration()
* with the values, or some modified version of them.
*
* Since: 1.6
*/
gboolean
gst_clock_add_observation_unapplied (GstClock * clock, GstClockTime slave,
GstClockTime master, gdouble * r_squared,
GstClockTime * internal, GstClockTime * external,
GstClockTime * rate_num, GstClockTime * rate_denom)
{
GstClockTime m_num, m_denom, b, xbase;
GstClockPrivate *priv;
guint n;
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;
n = priv->filling ? priv->time_index : priv->window_size;
if (!_priv_gst_do_linear_regression (priv->times, n, &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 (internal)
*internal = xbase;
if (external)
*external = b;
if (rate_num)
*rate_num = m_num;
if (rate_denom)
*rate_denom = 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;
}
}
