Class: Gst::Clock

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Overview

GStreamer clock class. Override the vmethods to implement the clock
functionality.

Direct Known Subclasses

SystemClock

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Object

#add_control_binding, check_uniqueness, #control_bindings_disabled=, #control_rate, #control_rate=, default_deep_notify, #default_error, #get_control_binding, #get_g_value_array, #get_value, #get_value_array, #has_active_control_bindings, #has_ancestor, #has_as_ancestor, #has_as_parent, #name, #name=, #parent, #parent=, #path_string, #ref, ref_sink, #remove_control_binding, replace, #set_control_binding_disabled, #suggest_next_sync, #sync_values, #unparent, #unref

Class Method Details

.id_compare_func(id1, id2) ⇒ Integer

Compares the two Gst::ClockID instances. This function can be used
as a GCompareFunc when sorting ids.

Parameters:

  • id1 (GObject) —

    A Gst::ClockID

  • id2 (GObject) —

    A Gst::ClockID to compare with

Returns:

  • (Integer) —

    negative value if a < b; zero if a = b; positive value if a > b

.id_get_clock(id) ⇒ Gst::Clock

This function returns the underlying clock.

Parameters:

  • id (Gst::ClockID) —

    a Gst::ClockID

Returns:

  • (Gst::Clock) —

    a Gst::Clock or nil when the
    underlying clock has been freed.

.id_get_time(id) ⇒ Gst::ClockTime

Gets the time of the clock ID

Parameters:

  • id (Gst::ClockID) —

    The Gst::ClockID to query

Returns:

  • (Gst::ClockTime) —

    the time of the given clock id.

.id_ref(id) ⇒ Gst::ClockID

Increases the refcount of given id.

Parameters:

  • id (Gst::ClockID) —

    The Gst::ClockID to ref

Returns:

  • (Gst::ClockID) —

    The same Gst::ClockID with increased refcount.

.id_unref(id) ⇒ nil

Unrefs given id. When the refcount reaches 0 the
Gst::ClockID will be freed.

Parameters:

  • id (Gst::ClockID) —

    The Gst::ClockID to unref

Returns:

  • (nil)

.id_unschedule(id) ⇒ nil

Cancels 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 Gst::ClockID.

Parameters:

  • id (Gst::ClockID) —

    The id to unschedule

Returns:

  • (nil)

.id_uses_clock(id, clock) ⇒ Boolean

This function returns whether id uses clock as the underlying clock.
clock can be NULL, in which case the return value indicates whether
the underlying clock has been freed. If this is the case, the id is
no longer usable and should be freed.

Parameters:

  • id (Gst::ClockID) —

    a Gst::ClockID to check

  • clock (Gst::Clock) —

    a Gst::Clock to compare against

Returns:

  • (Boolean) —

    whether the clock id uses the same underlying Gst::Clock clock.

.id_wait(id, jitter) ⇒ Gst::ClockReturn

Performs a blocking wait on id.
id should have been created with gst_clock_new_single_shot_id()
or gst_clock_new_periodic_id() and should not have been unscheduled
with a call to gst_clock_id_unschedule().

If the jitter argument is not nil and this function returns #GST_CLOCK_OK
or #GST_CLOCK_EARLY, it will contain the difference
against the clock and the time of id when this method was
called.
Positive values indicate how late id was relative to the clock
(in which case this function will return #GST_CLOCK_EARLY).
Negative values indicate how much time was spent waiting on the clock
before this function returned.
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().

Parameters:

  • id (Gst::ClockID) —

    The Gst::ClockID to wait on

  • jitter (Gst::ClockTimeDiff) —

    a pointer that will contain the jitter,
    can be nil.

Returns:

  • (Gst::ClockReturn) —

    the result of the blocking wait. #GST_CLOCK_EARLY will be returned

.id_wait_async(id, func, user_data, destroy_data) ⇒ Gst::ClockReturn

Registers a callback on the given Gst::ClockID id with the given
function and user_data. When passing a Gst::ClockID 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.

Parameters:

  • id (Gst::ClockID) —

    a Gst::ClockID to wait on

  • func (Gst::ClockCallback) —

    The callback function

  • user_data (GObject) —

    User data passed in the callback

  • destroy_data (GLib::DestroyNotify) —

    GDestroy::Notify for user_data

Returns:

Instance Method Details

#add_observation(slave, master, r_squared) ⇒ Boolean

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.
regression algorithm.

Parameters:

  • slave (Gst::ClockTime) —

    a time on the slave

  • master (Gst::ClockTime) —

    a time on the master

  • r_squared (Float) —

    a pointer to hold the result

Returns:

  • (Boolean) —

    true if enough observations were added to run the

#add_observation_unapplied(slave, master, r_squared, internal, external, rate_num, rate_denom) ⇒ Boolean

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.
regression algorithm.

Parameters:

  • slave (Gst::ClockTime) —

    a time on the slave

  • master (Gst::ClockTime) —

    a time on the master

  • r_squared (Float) —

    a pointer to hold the result

  • internal (Gst::ClockTime) —

    a location to store the internal time

  • external (Gst::ClockTime) —

    a location to store the external time

  • rate_num (Gst::ClockTime) —

    a location to store the rate numerator

  • rate_denom (Gst::ClockTime) —

    a location to store the rate denominator

Returns:

  • (Boolean) —

    true if enough observations were added to run the

#adjust_unlocked(internal) ⇒ Gst::ClockTime

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().

Parameters:

  • internal (Gst::ClockTime) —

    a clock time

Returns:

  • (Gst::ClockTime) —

    the converted time of the clock.

#adjust_with_calibration(internal_target, cinternal, cexternal, cnum, cdenom) ⇒ Gst::ClockTime

Converts the given internal_target clock time to the external time,
using the passed calibration parameters. This function performs the
same calculation as gst_clock_adjust_unlocked() when called using the
current calibration parameters, but doesn't ensure a monotonically
increasing result as gst_clock_adjust_unlocked() does.

Note: The clock parameter is unused and can be NULL

Parameters:

  • internal_target (Gst::ClockTime) —

    a clock time

  • cinternal (Gst::ClockTime) —

    a reference internal time

  • cexternal (Gst::ClockTime) —

    a reference external time

  • cnum (Gst::ClockTime) —

    the numerator of the rate of the clock relative to its
    internal time

  • cdenom (Gst::ClockTime) —

    the denominator of the rate of the clock

Returns:

  • (Gst::ClockTime) —

    the converted time of the clock.

#get_calibration(internal, external, rate_num, rate_denom) ⇒ nil

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 nil if the
caller is not interested in the values.

Parameters:

  • internal (Gst::ClockTime) —

    a location to store the internal time

  • external (Gst::ClockTime) —

    a location to store the external time

  • rate_num (Gst::ClockTime) —

    a location to store the rate numerator

  • rate_denom (Gst::ClockTime) —

    a location to store the rate denominator

Returns:

  • (nil)

#internal_time ⇒ Gst::ClockTime

Gets the current internal time of the given clock. The time is returned
unadjusted for the offset and the rate.
given invalid input.

Returns:

  • (Gst::ClockTime) —

    the internal time of the clock. Or %GST_CLOCK_TIME_NONE when

#is_synced ⇒ Boolean

Checks if the clock is currently synced, by looking at whether
%GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC is set.

Returns:

  • (Boolean) —

    true if the clock is currently synced

#master ⇒ Gst::Clock

Gets the master clock that clock is slaved to or nil when the clock is
not slaved to any master clock.

Returns:

  • (Gst::Clock) —

    a master Gst::Clock or nil
    when this clock is not slaved to a master clock.

#master=(master) ⇒ Boolean

Sets 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 nil 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.
Trying to set a master on a clock without the
#GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return false.

Parameters:

Returns:

  • (Boolean) —

    true if the clock is capable of being slaved to a master clock.

#new_periodic_id(start_time, interval) ⇒ Gst::ClockID

Gets an ID from clock to trigger a periodic notification.
The periodic notifications will start at time start_time and
will then be fired with the given interval.

Parameters:

  • start_time (Gst::ClockTime) —

    the requested start time

  • interval (Gst::ClockTime) —

    the requested interval

Returns:

  • (Gst::ClockID) —

    a Gst::ClockID that can be used to request the
    time notification.

#new_single_shot_id(time) ⇒ Gst::ClockID

Gets a Gst::ClockID from clock to trigger a single shot
notification at the requested time.

Parameters:

  • time (Gst::ClockTime) —

    the requested time

Returns:

  • (Gst::ClockID) —

    a Gst::ClockID that can be used to request the
    time notification.

#periodic_id_reinit(id, start_time, interval) ⇒ Boolean

Reinitializes the provided periodic id to the provided start time and
interval. Does not modify the reference count.
time, else false.

Parameters:

  • id (Gst::ClockID) —

    a Gst::ClockID

  • start_time (Gst::ClockTime) —

    the requested start time

  • interval (Gst::ClockTime) —

    the requested interval

Returns:

  • (Boolean) —

    true if the GstClockID could be reinitialized to the provided

#resolution ⇒ Gst::ClockTime

Gets the accuracy of the clock. The accuracy of the clock is the granularity
of the values returned by gst_clock_get_time().

Returns:

  • (Gst::ClockTime) —

    the resolution of the clock in units of Gst::ClockTime.

#resolution=(resolution) ⇒ Gst::ClockTime

Sets 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.

Parameters:

  • resolution (Gst::ClockTime) —

    The resolution to set

Returns:

  • (Gst::ClockTime) —

    the new resolution of the clock.

#set_calibration(internal, external, rate_num, rate_denom) ⇒ nil

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:

  time = (internal_time - internal) * rate_num / rate_denom + external

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.

Parameters:

  • internal (Gst::ClockTime) —

    a reference internal time

  • external (Gst::ClockTime) —

    a reference external time

  • rate_num (Gst::ClockTime) —

    the numerator of the rate of the clock relative to its
    internal time

  • rate_denom (Gst::ClockTime) —

    the denominator of the rate of the clock

Returns:

  • (nil)

#single_shot_id_reinit(id, time) ⇒ Boolean

Reinitializes the provided single shot id to the provided time. Does not
modify the reference count.
time, else false.

Parameters:

  • id (Gst::ClockID) —

    a Gst::ClockID

  • time (Gst::ClockTime) —

    The requested time.

Returns:

  • (Boolean) —

    true if the GstClockID could be reinitialized to the provided

#synced=(synced) ⇒ nil

Sets clock to synced and emits the Gst::Clock::synced signal, and wakes up any
thread waiting in gst_clock_wait_for_sync().

This function must only be called if %GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
is set on the clock, and is intended to be called by subclasses only.

Parameters:

  • synced (Boolean) —

    if the clock is synced

Returns:

  • (nil)

#time ⇒ Gst::ClockTime

Gets the current time of the given clock. The time is always
monotonically increasing and adjusted according to the current
offset and rate.
given invalid input.

Returns:

  • (Gst::ClockTime) —

    the time of the clock. Or %GST_CLOCK_TIME_NONE when

#timeout ⇒ Integer

Returns timeout.

Returns:

  • (Integer) —

    timeout

#timeout=(timeout) ⇒ Integer

Parameters:

  • timeout (Integer)

Returns:

  • (Integer) —

    timeout

  • (Integer) —

    timeout

#unadjust_unlocked(external) ⇒ Gst::ClockTime

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().

Parameters:

  • external (Gst::ClockTime) —

    an external clock time

Returns:

  • (Gst::ClockTime) —

    the internal time of the clock corresponding to external.

#unadjust_with_calibration(external_target, cinternal, cexternal, cnum, cdenom) ⇒ Gst::ClockTime

Converts the given external_target clock time to the internal time,
using the passed calibration parameters. This function performs the
same calculation as gst_clock_unadjust_unlocked() when called using the
current calibration parameters.

Note: The clock parameter is unused and can be NULL

Parameters:

  • external_target (Gst::ClockTime) —

    a clock time

  • cinternal (Gst::ClockTime) —

    a reference internal time

  • cexternal (Gst::ClockTime) —

    a reference external time

  • cnum (Gst::ClockTime) —

    the numerator of the rate of the clock relative to its
    internal time

  • cdenom (Gst::ClockTime) —

    the denominator of the rate of the clock

Returns:

  • (Gst::ClockTime) —

    the converted time of the clock.

#wait_for_sync(timeout) ⇒ Boolean

Waits until clock is synced for reporting the current time. If timeout
is %GST_CLOCK_TIME_NONE it will wait forever, otherwise it will time out
after timeout nanoseconds.

For asynchronous waiting, the Gst::Clock::synced signal can be used.

This returns immediately with true if %GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
is not set on the clock, or if the clock is already synced.

Parameters:

  • timeout (Gst::ClockTime) —

    timeout for waiting or %GST_CLOCK_TIME_NONE

Returns:

  • (Boolean) —

    true if waiting was successful, or false on timeout

#window_size ⇒ Integer

Returns window-size.

Returns:

  • (Integer) —

    window-size

#window_size=(window_size) ⇒ Integer

Parameters:

  • window_size (Integer)

Returns:

  • (Integer) —

    window-size

  • (Integer) —

    window-size

#window_threshold ⇒ Integer

Returns window-threshold.

Returns:

  • (Integer) —

    window-threshold

#window_threshold=(window_threshold) ⇒ Integer

Parameters:

  • window_threshold (Integer)

Returns:

  • (Integer) —

    window-threshold

  • (Integer) —

    window-threshold