Struct gstreamer::Element

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

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§

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

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§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Preferred value to be used as setter for the associated ParamSpec.
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
Override the virtual methods of this class for the given subclass and do other class initialization. Read more
Instance specific initialization. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==.
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
Returns the type identifier of Self.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
Upcasts an object to a superclass or interface T. Read more
Upcasts an object to a reference of its superclass or interface T. Read more
Tries to downcast to a subclass or interface implementor T. Read more
Tries to downcast to a reference of its subclass or interface implementor T. Read more
Tries to cast to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while downcast and upcast will do many checks at compile-time already. Read more
Tries to cast to reference to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while downcast and upcast will do many checks at compile-time already. Read more
Casts to T unconditionally. Read more
Casts to &T unconditionally. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Returns true if the object is an instance of (can be cast to) T.
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Returns the class of the object.
Returns the class of the object in the given type T. Read more
Returns the interface T of the object. Read more
Sets the property property_name of the object to value value. Read more
Sets the property property_name of the object to value value. Read more
Sets multiple properties of the object at once. Read more
Sets multiple properties of the object at once. Read more
Gets the property property_name of the object and cast it to the type V. Read more
Gets the property property_name of the object. Read more
Check if the object has a property property_name of the given type_. Read more
Get the type of the property property_name of this object. Read more
Get the ParamSpec of the property property_name of this object.
Return all ParamSpec of the properties of this object.
Freeze all property notifications until the return guard object is dropped. Read more
Set arbitrary data on this object with the given key. Read more
Return previously set arbitrary data of this object with the given key. Read more
Retrieve previously set arbitrary data of this object with the given key. Read more
Set arbitrary data on this object with the given key. Read more
Return previously set arbitrary data of this object with the given key. Read more
Retrieve previously set arbitrary data of this object with the given key. Read more
Block a given signal handler. Read more
Unblock a given signal handler.
Stop emission of the currently emitted signal.
Stop emission of the currently emitted signal by the (possibly detailed) signal name.
Connect to the signal signal_name on this object. Read more
Connect to the signal signal_id on this object. Read more
Connect to the signal signal_name on this object. Read more
Connect to the signal signal_id on this object. Read more
Connect to the signal signal_name on this object. Read more
Connect to the signal signal_id on this object. Read more
Connect a closure to the signal signal_name on this object. Read more
Connect a closure to the signal signal_id on this object. Read more
Limits the lifetime of closure to the lifetime of the object. When the object’s reference count drops to zero, the closure will be invalidated. An invalidated closure will ignore any calls to invoke_with_values, or invoke when using Rust closures.
Emit signal by signal id. Read more
Same as Self::emit but takes Value for the arguments.
Emit signal by its name. Read more
Emit signal by its name. Read more
Emit signal by its name with details. Read more
Emit signal by its name with details. Read more
Emit signal by signal id with details. Read more
Emit signal by signal id with details. Read more
Disconnect a previously connected signal handler.
Connect to the notify signal of the object. Read more
Connect to the notify signal of the object. Read more
Connect to the notify signal of the object. Read more
Notify that the given property has changed its value. Read more
Notify that the given property has changed its value. Read more
Downgrade this object to a weak reference.
Add a callback to be notified when the Object is disposed.
Add a callback to be notified when the Object is disposed. Read more
Bind property source_property on this object to the target_property on the target object. Read more
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Runs the dispose mechanism of the object. Read more
Ensures that the type has been registered with the type system.
The resulting type after obtaining ownership.
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Performs the conversion.
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