Struct gstreamer::Element

#[repr(transparent)]
pub struct Element { /* private fields */ }

GstElement is the abstract base class needed to construct an element that can be used in a GStreamer pipeline. Please refer to the plugin writers guide for more information on creating Element subclasses.

The name of a Element can be get with gst_element_get_name() and set with gst_element_set_name(). For speed, GST_ELEMENT_NAME() can be used in the core when using the appropriate locking. Do not use this in plug-ins or applications in order to retain ABI compatibility.

Elements can have pads (of the type Pad). These pads link to pads on other elements. Buffer flow between these linked pads. A Element has a GList of Pad structures for all their input (or sink) and output (or source) pads. Core and plug-in writers can add and remove pads with ElementExt::add_pad() and ElementExt::remove_pad().

An existing pad of an element can be retrieved by name with ElementExt::static_pad(). A new dynamic pad can be created using ElementExt::request_pad() with a PadTemplate. An iterator of all pads can be retrieved with ElementExtManual::iterate_pads().

Elements can be linked through their pads. If the link is straightforward, use the ElementExtManual::link() convenience function to link two elements, or [ElementExtManual::link_many()][crate::prelude::ElementExtManual::link_many()] for more elements in a row. Use ElementExtManual::link_filtered() to link two elements constrained by a specified set of Caps. For finer control, use ElementExtManual::link_pads() and ElementExtManual::link_pads_filtered() to specify the pads to link on each element by name.

Each element has a state (see State). You can get and set the state of an element with ElementExt::state() and ElementExt::set_state(). Setting a state triggers a StateChange. To get a string representation of a State, use gst_element_state_get_name().

You can get and set a Clock on an element using ElementExt::clock() and ElementExt::set_clock(). Some elements can provide a clock for the pipeline if the ElementFlags::PROVIDE_CLOCK flag is set. With the ElementExt::provide_clock() method one can retrieve the clock provided by such an element. Not all elements require a clock to operate correctly. If the ElementFlags::REQUIRE_CLOCK() flag is set, a clock should be set on the element with ElementExt::set_clock().

Note that clock selection and distribution is normally handled by the toplevel Pipeline so the clock functions are only to be used in very specific situations.

This is an Abstract Base Class, you cannot instantiate it.

Signals

no-more-pads

This signals that the element will not generate more dynamic pads. Note that this signal will usually be emitted from the context of the streaming thread.

pad-added

a new Pad has been added to the element. Note that this signal will usually be emitted from the context of the streaming thread. Also keep in mind that if you add new elements to the pipeline in the signal handler you will need to set them to the desired target state with ElementExt::set_state() or ElementExt::sync_state_with_parent().

pad-removed

a Pad has been removed from the element

Object

deep-notify

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.

Detailed

Implements

ElementExt, GstObjectExt, glib::ObjectExt, ElementExtManual

Implementations

impl Element

pub const NONE: Option<&'static Element> = None

pub fn make_from_uri( type_: URIType, uri: &str, elementname: Option<&str> ) -> Result<Element, Error>

Creates an element for handling the given URI.

type_

Whether to create a source or a sink

uri

URI to create an element for

elementname

Name of created element, can be None.

Returns

a new element or None if none could be created

impl Element

pub fn link_many( elements: impl IntoIterator<Item = impl AsRef<Element> + Clone> ) -> Result<(), BoolError>

pub fn unlink_many( elements: impl IntoIterator<Item = impl AsRef<Element> + Clone> )

pub fn register( plugin: Option<&Plugin>, name: &str, rank: Rank, type_: Type ) -> Result<(), BoolError>

Create a new elementfactory capable of instantiating objects of the type_ and add the factory to plugin.

plugin

Plugin to register the element with, or None for a static element.

name

name of elements of this type

rank

rank of element (higher rank means more importance when autoplugging)

type_

GType of element to register

Returns

true, if the registering succeeded, false on error

Trait Implementations

impl Clone for Element

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Element

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for Element

type ParamSpec = ParamSpecObject

type SetValue = Element

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, Element>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for Element

fn hash<H>(&self, state: &mut H)where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: ElementImpl> IsSubclassable<T> for Element

fn class_init(klass: &mut Class<Self>)

Override the virtual methods of this class for the given subclass and do other class initialization.

fn instance_init(instance: &mut InitializingObject<T>)

Instance specific initialization.

impl Ord for Element

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl ParentClassIs for Element

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for Element

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for Element

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for Element

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for Element

impl IsA<Element> for Bin

impl IsA<Element> for Pipeline

impl IsA<Element> for TagSetter

impl IsA<Element> for TocSetter

impl IsA<Object> for Element

impl Send for Element

impl Sync for Element