Struct gstreamer_editing_services::TrackElement

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

A TrackElement is a TimelineElement that specifically belongs to a single Track of its timeline. Its start and duration specify its temporal extent in the track. Specifically, a track element wraps some nleobject, such as an nlesource or nleoperation, which can be retrieved with TrackElementExt::nleobject(), and its start, duration, in-point, priority and active properties expose the corresponding nleobject properties. When a track element is added to a track, its nleobject is added to the corresponding nlecomposition that the track wraps.

Most users will not have to work directly with track elements since a Clip will automatically create track elements for its timeline’s tracks and take responsibility for updating them. The only track elements that are not automatically created by clips, but a user is likely to want to create, are Effect-s.

Control Bindings for Children Properties

You can set up control bindings for a track element child property using TrackElementExt::set_control_source(). A GstTimedValueControlSource should specify the timed values using the internal source coordinates (see TimelineElement). By default, these will be updated to lie between the in-point and out-point of the element. This can be switched off by setting auto-clamp-control-sources to false.

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

Properties

active

Whether the effect of the element should be applied in its track. If set to false, it will not be used in the output of the track.

Readable | Writeable

auto-clamp-control-sources

Whether the control sources on the element (see TrackElementExt::set_control_source()) will be automatically updated whenever the in-point or out-point of the element change in value.

See TrackElementExt::clamp_control_source() for how this is done per control source.

Default value: true

Readable | Writeable

has-internal-source

This property is used to determine whether the ‘internal time’ properties of the element have any meaning. In particular, unless this is set to true, the in-point and max-duration can not be set to any value other than the default 0 and GST_CLOCK_TIME_NONE, respectively.

If an element has some internal timed source gst::Element that it reads stream data from as part of its function in a Track, then you’ll likely want to set this to true to allow the in-point and max-duration to be set.

The default value is determined by the GESTrackElementClass default_has_internal_source class property. For most GESSourceClass-es, this will be true, with the exception of those that have a potentially static source, such as GESImageSourceClass and GESTitleSourceClass. Otherwise, this will usually be false.

For most Operation-s you will likely want to leave this set to false. The exception may be for an operation that reads some stream data from some private internal source as part of manipulating the input data from the usual linked upstream TrackElement.

For example, you may want to set this to true for a TrackType::VIDEO operation that wraps a textoverlay that reads from a subtitle file and places its text on top of the received video data. The in-point of the element would be used to shift the initial seek time on the textoverlay away from 0, and the max-duration could be set to reflect the time at which the subtitle file runs out of data.

Note that GES can not support track elements that have both internal content and manipulate the timing of their data streams (time effects).

Readable | Writeable

track

The track that this element belongs to, or None if it does not belong to a track.

Readable

track-type

The track type of the element, which determines the type of track the element can be added to (see track-type). This should correspond to the type of data that the element can produce or process.

Readable | Writeable | Construct

TimelineElement

duration

The duration that the element is in effect for in the timeline (a time difference in nanoseconds using the time coordinates of the timeline). For example, for a source element, this would determine for how long it should output its internal content for. For an operation element, this would determine for how long its effect should be applied to any source content.

Readable | Writeable

in-point

The initial offset to use internally when outputting content (in nanoseconds, but in the time coordinates of the internal content).

For example, for a VideoUriSource that references some media file, the “internal content” is the media file data, and the in-point would correspond to some timestamp in the media file. When playing the timeline, and when the element is first reached at timeline-time start, it will begin outputting the data from the timestamp in-point onwards, until it reaches the end of its duration in the timeline.

For elements that have no internal content, this should be kept as 0.

Readable | Writeable

max-duration

The full duration of internal content that is available (a time difference in nanoseconds using the time coordinates of the internal content).

This will act as a cap on the in-point of the element (which is in the same time coordinates), and will sometimes be used to limit the duration of the element in the timeline.

For example, for a VideoUriSource that references some media file, this would be the length of the media file.

For elements that have no internal content, or whose content is indefinite, this should be kept as GST_CLOCK_TIME_NONE.

Readable | Writeable | Construct

name

The name of the element. This should be unique within its timeline.

Readable | Writeable | Construct

parent

The parent container of the element.

Readable | Writeable

priority

The priority of the element.

Readable | Writeable

serialize

Whether the element should be serialized.

Readable | Writeable

start

The starting position of the element in the timeline (in nanoseconds and in the time coordinates of the timeline). For example, for a source element, this would determine the time at which it should start outputting its internal content. For an operation element, this would determine the time at which it should start applying its effect to any source content.

Readable | Writeable

timeline

The timeline that the element lies within.

Readable | Writeable

Signals

control-binding-added

This is emitted when a control binding is added to a child property of the track element.

control-binding-removed

This is emitted when a control binding is removed from a child property of the track element.

TimelineElement

child-property-added

Emitted when the element has a new child property registered. See TimelineElementExt::add_child_property().

Note that some GES elements will be automatically created with pre-registered children properties. You can use TimelineElementExt::list_children_properties() to list these.

child-property-removed

Emitted when the element has a child property unregistered. See TimelineElementExt::remove_child_property().

deep-notify

Emitted when a child of the element has one of its registered properties set. See TimelineElementExt::add_child_property(). Note that unlike notify, a child property name can not be used as a signal detail.

Detailed

MetaContainer

notify-meta

This is emitted for a meta container whenever the metadata under one of its fields changes, is set for the first time, or is removed. In the latter case, value will be None.

Detailed

Implements

TrackElementExt, TimelineElementExt, glib::ObjectExt, ExtractableExt, MetaContainerExt, [TimelineElementExtManual][trait@crate::prelude::TimelineElementExtManual]

Implementations

impl TrackElement

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

Trait Implementations

impl Clone for TrackElement

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 TrackElement

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

Formats the value using the given formatter.

impl HasParamSpec for TrackElement

type ParamSpec = ParamSpecObject

type SetValue = TrackElement

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

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

fn param_spec_builder() -> Self::BuilderFn

impl Hash for TrackElement

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 Ord for TrackElement

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 TrackElement

type Parent = TimelineElement

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

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 TrackElement

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 TrackElement

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for TrackElement

impl IsA<Extractable> for TrackElement

impl IsA<MetaContainer> for TrackElement

impl IsA<TimelineElement> for TrackElement

impl IsA<TrackElement> for AudioSource

impl IsA<TrackElement> for AudioTestSource

impl IsA<TrackElement> for AudioTransition

impl IsA<TrackElement> for AudioUriSource

impl IsA<TrackElement> for BaseEffect

impl IsA<TrackElement> for Effect

impl IsA<TrackElement> for ImageSource

impl IsA<TrackElement> for MultiFileSource

impl IsA<TrackElement> for Operation

impl IsA<TrackElement> for Source

impl IsA<TrackElement> for TextOverlay

impl IsA<TrackElement> for TitleSource

impl IsA<TrackElement> for Transition

impl IsA<TrackElement> for VideoSource

impl IsA<TrackElement> for VideoTestSource

impl IsA<TrackElement> for VideoTransition

impl IsA<TrackElement> for VideoUriSource