Object provides a root for the object hierarchy tree filed in by the GStreamer library.
It is currently a thin wrapper on top of InitiallyUnowned. It is an abstract class that is not very usable on
its own.
Object gives us basic refcounting, parenting functionality and locking. Most of the functions are
just extended for special GStreamer needs and can be found under the same name in the base class of Object
which is Object (e.g. @ref becomes
@ref).
Since Object derives from InitiallyUnowned, it also inherits the floating
reference. Be aware that functions such as add and
add_pad take ownership of the floating reference.
In contrast to Object instances, Object adds a name property. The
functions set_name and get_name
are used to set/get the name of the object.
typeof (unichar2)typeof
(unichar2) controlled properties
Controlled properties offers a lightweight way to adjust gobject properties over stream-time. It works by using time-stamped value pairs
that are queued for element-properties. At run-time the elements continuously pull value changes for the current stream-time.
What needs to be changed in a Element? Very little - it is just two steps to make a
plugin controllable!
* mark gobject-properties paramspecs that make sense to be controlled, by GST_PARAM_CONTROLLABLE.
* when processing data (get, chain, loop function) at the beginning call gst_object_sync_values(element,timestamp). This will make the
controller update all GObject properties that are under its control with the current values based on the timestamp.
What needs to be done in applications? Again it's not a lot to change.
* create a ControlSource. csource =
gst_interpolation_control_source_new; g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
* Attach the ControlSource on the controller to a property.
gst_object_add_control_binding (object, gst_direct_control_binding_new (object, "prop1", csource));
* Set the control values gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
* start your pipeline
- public unowned Object @ref ()
Increments the reference count on this
.
- public bool add_control_binding (ControlBinding binding)
- public void default_error (Error error, string? debug)
A default error function that uses printerr
to display the error message and the optional debug string.
- public ControlBinding? get_control_binding (string property_name)
- public ClockTime get_control_rate ()
Obtain the control-rate for this this
.
- public bool get_g_value_array (string property_name, ClockTime timestamp, ClockTime interval, Value[] values)
Gets a number of Values for the given
controlled property starting at the requested time.
- public string? get_name ()
Returns a copy of the name of this.
- public Object? get_parent ()
Returns the parent of this.
- public string get_path_string ()
Generates a string describing the path of
this in the object hierarchy.
- public Value? get_value (string property_name, ClockTime timestamp)
Gets the value for the given controlled property at the requested
time.
- public bool has_active_control_bindings ()
Check if the this has active
controlled properties.
- public bool has_ancestor (Object ancestor)
Check if this has an ancestor
ancestor somewhere up in the hierarchy.
- public bool has_as_ancestor (Object ancestor)
Check if this has an ancestor
ancestor somewhere up in the hierarchy.
- public bool has_as_parent (Object parent)
Check if parent is the parent of
this.
- public bool remove_control_binding (ControlBinding binding)
- public void set_control_binding_disabled (string property_name, bool disabled)
This function is used to disable the control bindings on a property
for some time, i.e. sync_values will do nothing for the property.
- public void set_control_bindings_disabled (bool disabled)
This function is used to disable all controlled properties of the
this for some time, i.e. sync_values will
do nothing.
- public void set_control_rate (ClockTime control_rate)
Change the control-rate for this this
.
- public bool set_name (string? name)
Sets the name of this, or gives
this a guaranteed unique name (if name is null).
- public bool set_parent (Object parent)
Sets the parent of this to
parent.
- public ClockTime suggest_next_sync ()
Returns a suggestion for timestamps where buffers should be split to
get best controller results.
- public bool sync_values (ClockTime timestamp)
Sets the properties of the object, according to the
ControlSources that (maybe) handle them and for the given timestamp.
- public void unparent ()
Clear the parent of this, removing
the associated reference.
- public void unref ()
Decrements the reference count on this
.