Internal$signalsCompile-time signal type information.
This instance property is generated only for TypeScript type checking. It is not defined at runtime and should not be accessed in JS code.
Tell an overlay that it has been exposed. This will redraw the current frame in the drawable even if the pipeline is PAUSED.
This will post a "have-window-handle" element message on the bus.
This function should only be used by video overlay plugin developers.
a platform-specific handle referencing the window
Tell an overlay that it should handle events from the window system. These events are forwarded upstream as navigation events. In some window system, events are not propagated in the window hierarchy if a client is listening for them. This method allows you to disable events handling completely from the GstVideo.VideoOverlay.
a gboolean indicating if events should be handled or not.
This will post a "prepare-window-handle" element message on the bus
to give applications an opportunity to call
gst_video_overlay_set_window_handle() before a plugin creates its own
window.
This function should only be used by video overlay plugin developers.
Configure a subregion as a video target within the window set by
gst_video_overlay_set_window_handle(). If this is not used or not supported
the video will fill the area of the window set as the overlay to 100%.
By specifying the rectangle, the video can be overlayed to a specific region
of that window only. After setting the new rectangle one should call
gst_video_overlay_expose() to force a redraw. To unset the region pass -1 for
the width and height parameters.
This method is needed for non fullscreen video overlay in UI toolkits that do not support subwindows.
the horizontal offset of the render area inside the window
the vertical offset of the render area inside the window
the width of the render area inside the window
the height of the render area inside the window
false if not supported by the sink.
This will call the video overlay's set_window_handle method. You
should use this method to tell to an overlay to display video output to a
specific window (e.g. an XWindow on X11). Passing 0 as the handle will
tell the overlay to stop using that window and create an internal one.
a handle referencing the window.
Creates a binding between source_property on source and target_property
on target.
Whenever the source_property is changed the target_property is
updated using the same value. For instance:
g_object_bind_property (action, "active", widget, "sensitive", 0);
Will result in the "sensitive" property of the widget GObject.Object instance to be updated with the same value of the "active" property of the action GObject.Object instance.
If flags contains GObject.BindingFlags.BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well.
The binding will automatically be removed when either the source or the
target instances are finalized. To remove the binding without affecting the
source and the target you can just call g_object_unref() on the returned
GObject.Binding instance.
Removing the binding by calling g_object_unref() on it must only be done if
the binding, source and target are only used from a single thread and it
is clear that both source and target outlive the binding. Especially it
is not safe to rely on this if the binding, source or target can be
finalized from different threads. Keep another reference to the binding and
use g_binding_unbind() instead to be on the safe side.
A GObject.Object can have multiple bindings.
the property on source to bind
the target GObject.Object
the property on target to bind
flags to pass to GObject.Binding
the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.
Complete version of g_object_bind_property().
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
If flags contains GObject.BindingFlags.BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well. The transform_from function is only used in case
of bidirectional bindings, otherwise it will be ignored
The binding will automatically be removed when either the source or the
target instances are finalized. This will release the reference that is
being held on the GObject.Binding instance; if you want to hold on to the
GObject.Binding instance, you will need to hold a reference to it.
To remove the binding, call g_binding_unbind().
A GObject.Object can have multiple bindings.
The same user_data parameter will be used for both transform_to
and transform_from transformation functions; the notify function will
be called once, when the binding is removed. If you need different data
for each transformation function, please use
g_object_bind_property_with_closures() instead.
the property on source to bind
the target GObject.Object
the property on target to bind
flags to pass to GObject.Binding
Optionaltransform_to: BindingTransformFuncthe transformation function from the source to the target, or null to use the default
Optionaltransform_from: BindingTransformFuncthe transformation function from the target to the source, or null to use the default
Optionalnotify: DestroyNotifya function to call when disposing the binding, to free resources used by the transformation functions, or null if not required
the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
This function is the language bindings friendly version of
g_object_bind_property_full(), using GClosures instead of
function pointers.
the property on source to bind
the target GObject.Object
the property on target to bind
flags to pass to GObject.Binding
a GObject.Closure wrapping the transformation function from the source to the target, or null to use the default
a GObject.Closure wrapping the transformation function from the target to the source, or null to use the default
the GObject.Binding instance representing the binding between the two GObject.Object instances. The binding is released whenever the GObject.Binding reference count reaches zero.
Blocks a handler of an instance so it will not be called during any signal emissions
Handler ID of the handler to be blocked
SignalconnectSignalconnect_Disconnects a handler from an instance so it will not be called during any future or currently ongoing emissions of the signal it has been connected to.
Handler ID of the handler to be disconnected
SignalemitThis function is intended for GObject.Object implementations to re-enforce
a floating object reference. Doing this is seldom
required: all GInitiallyUnowneds are created with a floating reference
which usually just needs to be sunken by calling g_object_ref_sink().
Increases the freeze count on object. If the freeze count is
non-zero, the emission of "notify" signals on object is
stopped. The signals are queued until the freeze count is decreased
to zero. Duplicate notifications are squashed so that at most one
GObject.Object::notify signal is emitted for each property modified while the
object is frozen.
This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
the data if found, or null if no such data exists.
Gets a property of an object.
The value can be:
In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling GObject.Value.unset.
Note that GObject.Object.get_property is really intended for language bindings, GObject.Object.get is much more convenient for C programming.
The name of the property to get
Return location for the property value. Can be an empty GObject.Value initialized by G_VALUE_INIT (auto-initialized with expected type since GLib 2.60), a GObject.Value initialized with the expected property type, or a GObject.Value initialized with a transformable type
This function gets back user data pointers stored via
g_object_set_qdata().
A GLib.Quark, naming the user data pointer
The user data pointer set, or null
Gets n_properties properties for an object.
Obtained properties will be set to values. All properties must be valid.
Warnings will be emitted and undefined behaviour may result if invalid
properties are passed in.
the names of each property to get
the values of each property to get
Checks whether object has a floating reference.
true if object has a floating reference
Emits a "notify" signal for the property property_name on object.
When possible, eg. when signaling a property change from within the class
that registered the property, you should use g_object_notify_by_pspec()
instead.
Note that emission of the notify signal may be blocked with
g_object_freeze_notify(). In this case, the signal emissions are queued
and will be emitted (in reverse order) when g_object_thaw_notify() is
called.
the name of a property installed on the class of object.
Emits a "notify" signal for the property specified by pspec on object.
This function omits the property name lookup, hence it is faster than
g_object_notify().
One way to avoid using g_object_notify() from within the
class that registered the properties, and using g_object_notify_by_pspec()
instead, is to store the GParamSpec used with
g_object_class_install_property() inside a static array, e.g.:
typedef enum
{
PROP_FOO = 1,
PROP_LAST
} MyObjectProperty;
static GParamSpec *properties[PROP_LAST];
static void
my_object_class_init (MyObjectClass *klass)
{
properties[PROP_FOO] = g_param_spec_int ("foo", NULL, NULL,
0, 100,
50,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
g_object_class_install_property (gobject_class,
PROP_FOO,
properties[PROP_FOO]);
}
and then notify a change on the "foo" property with:
g_object_notify_by_pspec (self, properties[PROP_FOO]);
the GObject.ParamSpec of a property installed on the class of object.
Increases the reference count of object.
Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type
of object will be propagated to the return type (using the GCC typeof()
extension), so any casting the caller needs to do on the return type must be
explicit.
the same object
Increase the reference count of object, and possibly remove the
floating reference, if object has a floating reference.
In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.
Since GLib 2.56, the type of object will be propagated to the return type
under the same conditions as for g_object_ref().
object
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Sets multiple properties of an object at once. The properties argument should be a dictionary mapping property names to values.
Object containing the properties to set
Each object carries around a table of associations from strings to pointers. This function lets you set an association.
If the object already had an association with that name, the old association will be destroyed.
Internally, the key is converted to a GLib.Quark using g_quark_from_string().
This means a copy of key is kept permanently (even after object has been
finalized) — so it is recommended to only use a small, bounded set of values
for key in your program, to avoid the GLib.Quark storage growing unbounded.
name of the key
Optionaldata: anydata to associate with that key
Sets a property on an object.
The name of the property to set
The value to set the property to
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
name of the key
the data if found, or null if no such data exists.
This function gets back user data pointers stored via
g_object_set_qdata() and removes the data from object
without invoking its destroy() function (if any was
set).
Usually, calling this function is only required to update
user data pointers with a destroy notifier, for example:
void
object_add_to_user_list (GObject *object,
const gchar *new_string)
{
// the quark, naming the object data
GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
// retrieve the old string list
GList *list = g_object_steal_qdata (object, quark_string_list);
// prepend new string
list = g_list_prepend (list, g_strdup (new_string));
// this changed 'list', so we need to set it again
g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
GList *node, *list = data;
for (node = list; node; node = node->next)
g_free (node->data);
g_list_free (list);
}
Using g_object_get_qdata() in the above example, instead of
g_object_steal_qdata() would have left the destroy function set,
and thus the partial string list would have been freed upon
g_object_set_qdata_full().
A GLib.Quark, naming the user data pointer
The user data pointer set, or null
Stops a signal's emission by the given signal name. This will prevent the default handler and any subsequent signal handlers from being invoked.
Name of the signal to stop emission of
Reverts the effect of a previous call to
g_object_freeze_notify(). The freeze count is decreased on object
and when it reaches zero, queued "notify" signals are emitted.
Duplicate notifications for each property are squashed so that at most one GObject.Object::notify signal is emitted for each property, in the reverse order in which they have been queued.
It is an error to call this function when the freeze count is zero.
Unblocks a handler so it will be called again during any signal emissions
Handler ID of the handler to be unblocked
Decreases the reference count of object. When its reference count
drops to 0, the object is finalized (i.e. its memory is freed).
If the pointer to the GObject.Object may be reused in future (for example, if it is
an instance variable of another object), it is recommended to clear the
pointer to null rather than retain a dangling pointer to a potentially
invalid GObject.Object instance. Use g_clear_object() for this.
Virtualvfunc_the constructed function is called by g_object_new() as the
final step of the object creation process. At the point of the call, all
construction properties have been set on the object. The purpose of this
call is to allow for object initialisation steps that can only be performed
after construction properties have been set. constructed implementors
should chain up to the constructed call of their parent class to allow it
to complete its initialisation.
Virtualvfunc_Virtualvfunc_the dispose function is supposed to drop all references to other
objects, but keep the instance otherwise intact, so that client method
invocations still work. It may be run multiple times (due to reference
loops). Before returning, dispose should chain up to the dispose method
of the parent class.
Virtualvfunc_instance finalization function, should finish the finalization of
the instance begun in dispose and chain up to the finalize method of the
parent class.
Virtualvfunc_Virtualvfunc_Emits a "notify" signal for the property property_name on object.
When possible, eg. when signaling a property change from within the class
that registered the property, you should use g_object_notify_by_pspec()
instead.
Note that emission of the notify signal may be blocked with
g_object_freeze_notify(). In this case, the signal emissions are queued
and will be emitted (in reverse order) when g_object_thaw_notify() is
called.
Virtualvfunc_the generic setter for all properties of this type. Should be
overridden for every type with properties. If implementations of
set_property don't emit property change notification explicitly, this will
be done implicitly by the type system. However, if the notify signal is
emitted explicitly, the type system will not emit it a second time.
This function essentially limits the life time of the closure to
the life time of the object. That is, when the object is finalized,
the closure is invalidated by calling g_closure_invalidate() on
it, in order to prevent invocations of the closure with a finalized
(nonexisting) object. Also, g_object_ref() and g_object_unref() are
added as marshal guards to the closure, to ensure that an extra
reference count is held on object during invocation of the
closure. Usually, this function will be called on closures that
use this object as closure data.
GObject.Closure to watch
Virtualvfunc_Tell an overlay that it has been exposed. This will redraw the current frame in the drawable even if the pipeline is PAUSED.
Virtualvfunc_Tell an overlay that it should handle events from the window system. These events are forwarded upstream as navigation events. In some window system, events are not propagated in the window hierarchy if a client is listening for them. This method allows you to disable events handling completely from the GstVideo.VideoOverlay.
a gboolean indicating if events should be handled or not.
Virtualvfunc_virtual method to set the render rectangle
Virtualvfunc_This will call the video overlay's set_window_handle method. You
should use this method to tell to an overlay to display video output to a
specific window (e.g. an XWindow on X11). Passing 0 as the handle will
tell the overlay to stop using that window and create an internal one.
a handle referencing the window.
The GstVideo.VideoOverlay interface is used for 2 main purposes :
Using the Window created by the video sink is probably the simplest scenario, in some cases, though, it might not be flexible enough for application developers if they need to catch events such as mouse moves and button clicks.
Setting a specific Window identifier on the video sink element is the most flexible solution but it has some issues. Indeed the application needs to set its Window identifier at the right time to avoid internal Window creation from the video sink element. To solve this issue a Gst.Message is posted on the bus to inform the application that it should set the Window identifier immediately. Here is an example on how to do that correctly:
Two basic usage scenarios
There are two basic usage scenarios: in the simplest case, the application uses #playbin or #playsink or knows exactly what particular element is used for video output, which is usually the case when the application creates the videosink to use (e.g. #xvimagesink, #ximagesink, etc.) itself; in this case, the application can just create the videosink element, create and realize the window to render the video on and then call
gst_video_overlay_set_window_handle()directly with the XID or native window handle, before starting up the pipeline. As #playbin and #playsink implement the video overlay interface and proxy it transparently to the actual video sink even if it is created later, this case also applies when using these elements.In the other and more common case, the application does not know in advance what GStreamer video sink element will be used for video output. This is usually the case when an element such as #autovideosink is used. In this case, the video sink element itself is created asynchronously from a GStreamer streaming thread some time after the pipeline has been started up. When that happens, however, the video sink will need to know right then whether to render onto an already existing application window or whether to create its own window. This is when it posts a prepare-window-handle message, and that is also why this message needs to be handled in a sync bus handler which will be called from the streaming thread directly (because the video sink will need an answer right then).
As response to the prepare-window-handle element message in the bus sync handler, the application may use
gst_video_overlay_set_window_handle()to tell the video sink to render onto an existing window surface. At this point the application should already have obtained the window handle / XID, so it just needs to set it. It is generally not advisable to call any GUI toolkit functions or window system functions from the streaming thread in which the prepare-window-handle message is handled, because most GUI toolkits and windowing systems are not thread-safe at all and a lot of care would be required to co-ordinate the toolkit and window system calls of the different threads (Gtk+ users please note: prior to Gtk+ 2.18GDK_WINDOW_XIDwas just a simple structure access, so generally fine to do within the bus sync handler; this macro was changed to a function call in Gtk+ 2.18 and later, which is likely to cause problems when called from a sync handler; see below for a better approach withoutGDK_WINDOW_XIDused in the callback).GstVideoOverlay and Gtk+
GstVideoOverlay and Qt