GhostPad

GhostPads are useful when organizing pipelines with GstBin 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 GstElement. 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, gst_ghost_pad_new() is the function to use to get a ghost-pad. Otherwise one can use gst_ghost_pad_new_no_target() to create the ghost-pad and use gst_ghost_pad_set_target() to establish the association later on.

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

Last reviewed on 2005-11-18 (0.9.5)

class GhostPad : ProxyPad {

protected

GstGhostPad* gstGhostPad;

GstGhostPad* getGhostPadStruct();

void* getStruct();

this(GstGhostPad* gstGhostPad);

void setStruct(GObject* obj);

this(string name, Pad target);

this(string name, GstPadDirection dir);

this(string name, Pad target, PadTemplate templ);

this(string name, PadTemplate templ);

int setTarget(Pad newtarget);

Pad getTarget();

int construct();

static int activateModeDefault(Pad pad, ObjectGst parent, GstPadMode mode, int active);

static int internalActivateModeDefault(Pad pad, ObjectGst parent, GstPadMode mode, int active);

}

Constructors

this this(GstGhostPad* gstGhostPad): Sets our main struct and passes it to the parent class
this this(string name, Pad target): 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.
this this(string name, GstPadDirection dir): Create a new ghostpad without a target with the given direction. A target can be set on the ghostpad later with the gst_ghost_pad_set_target() function. The created ghostpad will not have a padtemplate.
this this(string name, Pad target, PadTemplate templ): 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.
this this(string name, PadTemplate templ): Create a new ghostpad based on templ, without setting a target. The direction will be taken from the templ.

Members

Functions

construct int construct(): Finish initialization of a newly allocated ghost pad. This function is most useful in language bindings and when subclassing GstGhostPad; 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).
getGhostPadStruct GstGhostPad* getGhostPadStruct(): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getTarget Pad getTarget(): Get the target pad of gpad. Unref target pad after usage.
setStruct void setStruct(GObject* obj): Undocumented in source. Be warned that the author may not have intended to support it.
setTarget int setTarget(Pad newtarget): Set the new target of the ghostpad gpad. Any existing target is unlinked and links to the new target are established. if newtarget is NULL the target will be cleared.

Static functions

activateModeDefault int activateModeDefault(Pad pad, ObjectGst parent, GstPadMode mode, int active): Invoke the default activate mode function of a ghost pad.
internalActivateModeDefault int internalActivateModeDefault(Pad pad, ObjectGst parent, GstPadMode mode, int active): Invoke the default activate mode function of a proxy pad that is owned by a ghost pad.

Variables

gstGhostPad GstGhostPad* gstGhostPad;: the main Gtk struct

Inherited Members

From ProxyPad

gstProxyPad GstProxyPad* gstProxyPad;: the main Gtk struct
getProxyPadStruct GstProxyPad* getProxyPadStruct(): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
setStruct void setStruct(GObject* obj): Undocumented in source. Be warned that the author may not have intended to support it.
getInternal ProxyPad getInternal(): Get the internal pad of pad. Unref target pad after usage. The internal pad of a GstGhostPad is the internally used pad of opposite direction, which is used to link to the target.
iterateInternalLinksDefault Iterator iterateInternalLinksDefault(ObjectGst parent): Invoke the default iterate internal links function of the proxy pad.
chainDefault GstFlowReturn chainDefault(ObjectGst parent, Buffer buffer): Invoke the default chain function of the proxy pad.
chainListDefault GstFlowReturn chainListDefault(ObjectGst parent, BufferList list): Invoke the default chain list function of the proxy pad.
getrangeDefault GstFlowReturn getrangeDefault(ObjectGst parent, ulong offset, uint size, Buffer buffer): returns GST_FLOW_ERROR if NULL. Invoke the default getrange function of the proxy pad.