PadTemplate

Description Padtemplates describe the possible media types a pad or an elementfactory can handle. This allows for both inspection of handled types before loading the element plugin as well as identifying pads on elements that are not yet created (request or sometimes pads). Pad and PadTemplates have GstCaps attached to it to describe the media type they are capable of dealing with. gst_pad_template_get_caps() or GST_PAD_TEMPLATE_CAPS() are used to get the caps of a padtemplate. It's not possible to modify the caps of a padtemplate after creation. PadTemplates have a GstPadPresence property which identifies the lifetime of the pad and that can be retrieved with GST_PAD_TEMPLATE_PRESENCE(). Also the direction of the pad can be retrieved from the GstPadTemplate with GST_PAD_TEMPLATE_DIRECTION(). The GST_PAD_TEMPLATE_NAME_TEMPLATE() is important for GST_PAD_REQUEST pads because it has to be used as the name in the gst_element_request_pad_by_name() call to instantiate a pad from this template. Padtemplates can be created with gst_pad_template_new() or with gst_static_pad_template_get(), which creates a GstPadTemplate from a GstStaticPadTemplate that can be filled with the convenient GST_STATIC_PAD_TEMPLATE() macro. A padtemplate can be used to create a pad (see gst_pad_new_from_template() or gst_pad_new_from_static_template()) or to add to an element class (see gst_element_class_add_pad_template()). The following code example shows the code to create a pad from a padtemplate. The following example shows you how to add the padtemplate to an element class, this is usually done in the base_init of the class: Last reviewed on 2006-02-14 (0.10.3)

Constructors

this
this(GstPadTemplate* gstPadTemplate)

Sets our main struct and passes it to the parent class

this
this(string nameTemplate, GstPadDirection direction, GstPadPresence presence, Caps caps)

Creates a new pad template with a name according to the given template and with the given arguments. This functions takes ownership of the provided caps, so be sure to not use them afterwards.

Members

Functions

addOnPadCreated
void addOnPadCreated(void delegate(Pad, PadTemplate) dlg, ConnectFlags connectFlags)

This signal is fired when an element creates a pad from this template. See Also GstPad, GstElementFactory

getCaps
Caps getCaps()

Gets the capabilities of the pad template.

getPadTemplateStruct
GstPadTemplate* getPadTemplateStruct()
Undocumented in source. Be warned that the author may not have intended to support it.
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.

Static functions

callBackPadCreated
void callBackPadCreated(GstPadTemplate* padTemplateStruct, GstPad* pad, PadTemplate _padTemplate)
Undocumented in source. Be warned that the author may not have intended to support it.
staticPadTemplateGet
PadTemplate staticPadTemplateGet(GstStaticPadTemplate* padTemplate)

Converts a GstStaticPadTemplate into a GstPadTemplate.

staticPadTemplateGetCaps
Caps staticPadTemplateGetCaps(GstStaticPadTemplate* templ)

Gets the capabilities of the static pad template.

Variables

connectedSignals
int[string] connectedSignals;
gstPadTemplate
GstPadTemplate* gstPadTemplate;

the main Gtk struct

onPadCreatedListeners
void delegate(Pad, PadTemplate)[] onPadCreatedListeners;
Undocumented in source.

Inherited Members

From ObjectGst

gstObject
GstObject* gstObject;

the main Gtk struct

getObjectGstStruct
GstObject* getObjectGstStruct()
Undocumented in source. Be warned that the author may not have intended to support it.
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.
connectedSignals
int[string] connectedSignals;
onDeepNotifyListeners
void delegate(ObjectGst, ParamSpec, ObjectGst)[] onDeepNotifyListeners;
Undocumented in source.
addOnDeepNotify
void addOnDeepNotify(void delegate(ObjectGst, ParamSpec, ObjectGst) dlg, ConnectFlags connectFlags)

The deep notify signal is used to be notified of property changes. It is typically attached to the toplevel bin to receive notifications from all the elements contained in that bin.

callBackDeepNotify
void callBackDeepNotify(GstObject* gstobjectStruct, GstObject* propObject, GParamSpec* prop, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
onObjectSavedListeners
void delegate(void*, ObjectGst)[] onObjectSavedListeners;
Undocumented in source.
addOnObjectSaved
void addOnObjectSaved(void delegate(void*, ObjectGst) dlg, ConnectFlags connectFlags)

Trigered whenever a new object is saved to XML. You can connect to this signal to insert custom XML tags into the core XML.

callBackObjectSaved
void callBackObjectSaved(GstObject* gstobjectStruct, void* xmlNode, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
onParentSetListeners
void delegate(ObjectG, ObjectGst)[] onParentSetListeners;
Undocumented in source.
addOnParentSet
void addOnParentSet(void delegate(ObjectG, ObjectGst) dlg, ConnectFlags connectFlags)

Emitted when the parent of an object is set.

callBackParentSet
void callBackParentSet(GstObject* gstobjectStruct, GObject* parent, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
onParentUnsetListeners
void delegate(ObjectG, ObjectGst)[] onParentUnsetListeners;
Undocumented in source.
addOnParentUnset
void addOnParentUnset(void delegate(ObjectG, ObjectGst) dlg, ConnectFlags connectFlags)

Emitted when the parent of an object is unset.

callBackParentUnset
void callBackParentUnset(GstObject* gstobjectStruct, GObject* parent, ObjectGst _objectGst)
Undocumented in source. Be warned that the author may not have intended to support it.
setName
int setName(string name)

Sets the name of object, or gives object a guaranteed unique name (if name is NULL). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.

getName
string getName()

Returns a copy of the name of object. Caller should g_free() the return value after usage. For a nameless object, this returns NULL, which you can safely g_free() as well.

setParent
int setParent(ObjectGst parent)

Sets the parent of object to parent. The object's reference count will be incremented, and any floating reference will be removed (see gst_object_sink()). This function causes the parent-set signal to be emitted when the parent was successfully set.

getParent
ObjectGst getParent()

Returns the parent of object. This function increases the refcount of the parent object so you should gst_object_unref() it after usage.

unparent
void unparent()

Clear the parent of object, removing the associated reference. This function decreases the refcount of object. MT safe. Grabs and releases object's lock.

getNamePrefix
string getNamePrefix()

Returns a copy of the name prefix of object. Caller should g_free() the return value after usage. For a prefixless object, this returns NULL, which you can safely g_free() as well.

setNamePrefix
void setNamePrefix(string namePrefix)

Sets the name prefix of object to name_prefix. This function makes a copy of the provided name prefix, so the caller retains ownership of the name prefix it sent. MT safe. This function grabs and releases object's LOCK.

defaultDeepNotify
void defaultDeepNotify(ObjectG object, ObjectGst orig, ParamSpec pspec, string[] excludedProps)

A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print. MT safe. This function grabs and releases object's LOCK for getting its path string.

defaultError
void defaultError(ErrorG error, string dbug)

A default error function. The default handler will simply print the error string using g_print.

checkUniqueness
int checkUniqueness(ListG list, string name)

Checks to see if there is any object named name in list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each GstObject in the list to compare the name, so be carefull when passing a list with a locked object.

hasAncestor
int hasAncestor(ObjectGst ancestor)

Check if object has an ancestor ancestor somewhere up in the hierarchy.

doref
void* doref(void* object)

Increments the refence count on object. This function does not take the lock on object because it relies on atomic refcounting. This object returns the input parameter to ease writing

unref
void unref(void* object)

Decrements the refence count on object. If reference count hits zero, destroy object. This function does not take the lock on object as it relies on atomic refcounting. The unref method should never be called with the LOCK held since this might deadlock the dispose function.

sink
void sink(void* object)

If object was floating, the GST_OBJECT_FLOATING flag is removed and object is unreffed. When object was not floating, this function does nothing. Any newly created object has a refcount of 1 and is floating. This function should be used when creating a new object to symbolically 'take ownership' of object. This done by first doing a gst_object_ref() to keep a reference to object and then gst_object_sink() to remove and unref any floating references to object. Use gst_object_set_parent() to have this done for you. MT safe. This function grabs and releases object lock.

replace
void replace(ObjectGst oldobj, ObjectGst newobj)

Unrefs the GstObject pointed to by oldobj, refs newobj and puts newobj in *oldobj. Be carefull when calling this function, it does not take any locks. You might want to lock the object owning oldobj pointer before calling this function. Make sure not to LOCK oldobj because it might be unreffed which could cause a deadlock when it is disposed.

getPathString
string getPathString()

Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging.

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