GhostPad#

class GhostPad(**properties: Any)#

Superclasses: ProxyPad, Pad, Object, InitiallyUnowned, Object

GhostPads are useful when organizing pipelines with Bin like elements. The idea here is to create hierarchical element graphs. The bin element contains a sub-graph. Now one would like to treat the bin-element like any other Element. This is where GhostPads come into play. A GhostPad acts as a proxy for another pad. Thus the bin can have sink and source ghost-pads that are associated with sink and source pads of the child elements.

If the target pad is known at creation time, new() is the function to use to get a ghost-pad. Otherwise one can use new_no_target() to create the ghost-pad and use set_target() to establish the association later on.

Note that GhostPads add overhead to the data processing of a pipeline.

Constructors#

class GhostPad
classmethod new(name: str | None, target: Pad) → Pad | None#

Create a new ghostpad with target as the target. The direction will be taken from the target pad. target must be unlinked.

Will ref the target.

Parameters:

  • name – the name of the new pad, or None to assign a default name

  • target – the pad to ghost.

classmethod new_from_template(name: str | None, target: Pad, templ: PadTemplate) → Pad | None#

Create a new ghostpad with target as the target. The direction will be taken from the target pad. The template used on the ghostpad will be template.

Will ref the target.

Parameters:

  • name – the name of the new pad, or None to assign a default name.

  • target – the pad to ghost.

  • templ – the PadTemplate to use on the ghostpad.

classmethod new_no_target(name: str | None, dir: PadDirection) → Pad | None#

Create a new ghostpad without a target with the given direction. A target can be set on the ghostpad later with the set_target() function.

The created ghostpad will not have a padtemplate.

Parameters:

  • name – the name of the new pad, or None to assign a default name.

  • dir – the direction of the ghostpad

classmethod new_no_target_from_template(name: str | None, templ: PadTemplate) → Pad | None#

Create a new ghostpad based on templ, without setting a target. The direction will be taken from the templ.

Parameters:

  • name – the name of the new pad, or None to assign a default name

  • templ – the PadTemplate to create the ghostpad from.

Methods#

class GhostPad
classmethod activate_mode_default(parent: Object | None, mode: PadMode, active: bool) → bool#

Invoke the default activate mode function of a ghost pad.

Parameters:

  • parent – the parent of pad or None

  • mode – the requested activation mode

  • active – whether the pad should be active or not.

construct() → bool#

Finish initialization of a newly allocated ghost pad.

This function is most useful in language bindings and when subclassing GhostPad; plugin and application developers normally will not call this function. Call this function directly after a call to g_object_new (GST_TYPE_GHOST_PAD, “direction”, dir, …, NULL).

Deprecated since version Unknown: This function is deprecated since 1.18 and does nothing anymore.

get_target() → Pad | None#

Get the target pad of gpad. Unref target pad after usage.

classmethod internal_activate_mode_default(parent: Object | None, mode: PadMode, active: bool) → bool#

Invoke the default activate mode function of a proxy pad that is owned by a ghost pad.

Parameters:

  • parent – the parent of pad or None

  • mode – the requested activation mode

  • active – whether the pad should be active or not.

set_target(newtarget: Pad | None = None) → bool#

Set the new target of the ghostpad gpad. Any existing target is unlinked and links to the new target are established. if newtarget is None the target will be cleared.

Parameters:

newtarget – the new pad target

Fields#

class GhostPad
pad#
priv#