Gst.ElementClass

Fields

Name

Type

Access

Description

change_state

object

r

elementfactory

Gst.ElementFactory

r

the Gst.ElementFactory that creates these elements

get_state

object

r

metadata

object

r

metadata for elements of this class

no_more_pads

object

r

numpadtemplates

int

r

the number of padtemplates

pad_added

object

r

pad_removed

object

r

pad_templ_cookie

int

r

changed whenever the padtemplates change

padtemplates

[object]

r

a GLib.List of Gst.PadTemplate

parent_class

Gst.ObjectClass

r

the parent class structure

post_message

object

r

provide_clock

object

r

query

object

r

release_pad

object

r

request_new_pad

object

r

send_event

object

r

set_bus

object

r

set_clock

object

r

set_context

object

r

set_state

object

r

state_changed

object

r

Methods

add_metadata (key, value)

add_pad_template (templ)

add_static_metadata (key, value)

add_static_pad_template (static_templ)

add_static_pad_template_with_gtype (static_templ, pad_type)

get_metadata (key)

get_pad_template (name)

get_pad_template_list ()

set_metadata (longname, classification, description, author)

set_static_metadata (longname, classification, description, author)

Details

class Gst.ElementClass

GStreamer element class. Override the vmethods to implement the element functionality.

add_metadata(key, value)[source]
Parameters
  • key (str) – the key to set

  • value (str) – the value to set

Set key with value as metadata in self.

add_pad_template(templ)[source]
Parameters

templ (Gst.PadTemplate) – a Gst.PadTemplate to add to the element class.

Adds a padtemplate to an element class. This is mainly used in the _class_init functions of classes. If a pad template with the same name as an already existing one is added the old one is replaced by the new one.

templ's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink())

add_static_metadata(key, value)[source]
Parameters
  • key (str) – the key to set

  • value (str) – the value to set

Set key with value as metadata in self.

Same as Gst.ElementClass.add_metadata(), but value must be a static string or an inlined string, as it will not be copied. (GStreamer plugins will be made resident once loaded, so this function can be used even from dynamically loaded plugins.)

add_static_pad_template(static_templ)[source]
Parameters

static_templ (Gst.StaticPadTemplate) – Gst.StaticPadTemplate to add as pad template to the element class.

Adds a pad template to an element class based on the static pad template templ. This is mainly used in the _class_init functions of element implementations. If a pad template with the same name already exists, the old one is replaced by the new one.

New in version 1.8.

add_static_pad_template_with_gtype(static_templ, pad_type)[source]
Parameters

Adds a pad template to an element class based on the static pad template templ. This is mainly used in the _class_init functions of element implementations. If a pad template with the same name already exists, the old one is replaced by the new one.

New in version 1.14.

get_metadata(key)[source]
Parameters

key (str) – the key to get

Returns

the metadata for key.

Return type

str

Get metadata with key in self.

get_pad_template(name)[source]
Parameters

name (str) – the name of the Gst.PadTemplate to get.

Returns

the Gst.PadTemplate with the given name, or None if none was found. No unreferencing is necessary.

Return type

Gst.PadTemplate or None

Retrieves a padtemplate from self with the given name.

If you use this function in the GObject.InstanceInitFunc of an object class that has subclasses, make sure to pass the g_class parameter of the GObject.InstanceInitFunc here.

get_pad_template_list()[source]
Returns

the GLib.List of pad templates.

Return type

[Gst.PadTemplate]

Retrieves a list of the pad templates associated with self. The list must not be modified by the calling code.

If you use this function in the GObject.InstanceInitFunc of an object class that has subclasses, make sure to pass the g_class parameter of the GObject.InstanceInitFunc here.

set_metadata(longname, classification, description, author)[source]
Parameters
  • longname (str) – The long English name of the element. E.g. “File Sink”

  • classification (str) – String describing the type of element, as an unordered list separated with slashes (‘/’). See draft-klass.txt of the design docs for more details and common types. E.g: “Sink/File”

  • description (str) – Sentence describing the purpose of the element. E.g: “Write stream to a file”

  • author (str) – Name and contact details of the author(s). Use \n to separate multiple author metadata. E.g: “Joe Bloggs <joe.blogs at foo.com>”

Sets the detailed information for a Gst.ElementClass.

This function is for use in _class_init functions only.

set_static_metadata(longname, classification, description, author)[source]
Parameters
  • longname (str) – The long English name of the element. E.g. “File Sink”

  • classification (str) – String describing the type of element, as an unordered list separated with slashes (‘/’). See draft-klass.txt of the design docs for more details and common types. E.g: “Sink/File”

  • description (str) – Sentence describing the purpose of the element. E.g: “Write stream to a file”

  • author (str) – Name and contact details of the author(s). Use \n to separate multiple author metadata. E.g: “Joe Bloggs <joe.blogs at foo.com>”

Sets the detailed information for a Gst.ElementClass.

This function is for use in _class_init functions only.

Same as Gst.ElementClass.set_metadata(), but longname, classification, description, and author must be static strings or inlined strings, as they will not be copied. (GStreamer plugins will be made resident once loaded, so this function can be used even from dynamically loaded plugins.)