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

A Track acts an output source for a Timeline. Each one essentially provides an additional gst::Pad for the timeline, with restriction-caps capabilities. Internally, a track wraps an nlecomposition filtered by a capsfilter.

A track will contain a number of TrackElement-s, and its role is to select and activate these elements according to their timings when the timeline in played. For example, a track would activate a Source when its start is reached by outputting its data for its duration. Similarly, a Operation would be activated by applying its effect to the source data, starting from its start time and lasting for its duration.

For most users, it will usually be sufficient to add newly created tracks to a timeline, but never directly add an element to a track. Whenever a Clip is added to a timeline, the clip adds its elements to the timeline’s tracks and assumes responsibility for updating them.

Properties

caps

The capabilities used to choose the output of the Track’s elements. Internally, this is used to select output streams when several may be available, by determining whether its gst::Pad is compatible (see NleObject:caps for nlecomposition). As such, this is used as a weaker indication of the desired output type of the track, before the restriction-caps is applied. Therefore, this should be set to a generic superset of the restriction-caps, such as “video/x-raw(ANY)”. In addition, it should match with the track’s track-type.

Note that when you set this property, the GstCapsFeatures of all its gst::Structure-s will be automatically set to GST_CAPS_FEATURES_ANY.

Once a track has been added to a Timeline, you should not change this.

Default value: GST_CAPS_ANY.

Readable | Writeable | Construct Only

duration

Current duration of the track

Default value: O

Readable

id

The nlecomposition:id of the underlying nlecomposition.

Readable | Writeable

mixing

Whether the track should support the mixing of Layer data, such as composing the video data of each layer (when part of the video data is transparent, the next layer will become visible) or adding together the audio data. As such, for audio and video tracks, you’ll likely want to keep this set to true.

Readable | Writeable | Construct

restriction-caps

The capabilities that specifies the final output format of the Track. For example, for a video track, it would specify the height, width, framerate and other properties of the stream.

You may change this property after the track has been added to a Timeline, but it must remain compatible with the track’s caps.

Default value: GST_CAPS_ANY.

Readable | Writeable

track-type

The track type of the track. This controls the type of TrackElement-s that can be added to the track. This should match with the track’s caps.

Once a track has been added to a Timeline, you should not change this.

Readable | Writeable | Construct Only

Bin

async-handling

If set to true, the bin will handle asynchronous state changes. This should be used only if the bin subclass is modifying the state of its children on its own.

Readable | Writeable

message-forward

Forward all children messages, even those that would normally be filtered by the bin. This can be interesting when one wants to be notified of the EOS state of individual elements, for example.

The messages are converted to an ELEMENT message with the bin as the source. The structure of the message is named GstBinForwarded and contains a field named message that contains the original forwarded GstMessage.

Readable | Writeable

Object

name

Readable | Writeable | Construct

parent

The parent of the object. Please note, that when changing the ‘parent’ property, we don’t emit notify and deep-notify signals due to locking issues. In some cases one can use element-added or element-removed signals on the parent to achieve a similar effect.

Readable | Writeable

Signals

commited

This signal will be emitted once the changes initiated by GESTrackExt::commit() have been executed in the backend. In particular, this will be emitted whenever the underlying nlecomposition has been committed (see nlecomposition::commited).

track-element-added

Will be emitted after a track element is added to the track.

track-element-removed

Will be emitted after a track element is removed from the track.

Bin

deep-element-added

Will be emitted after the element was added to sub_bin.

deep-element-removed

Will be emitted after the element was removed from sub_bin.

do-latency

Will be emitted when the bin needs to perform latency calculations. This signal is only emitted for toplevel bins or when async-handling is enabled.

Only one signal handler is invoked. If no signals are connected, the default handler is invoked, which will query and distribute the lowest possible latency to all sinks.

Connect to this signal if the default latency calculations are not sufficient, like when you need different latencies for different sinks in the same pipeline.

element-added

Will be emitted after the element was added to the bin.

element-removed

Will be emitted after the element was removed from the bin.

Element

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 gst::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 [ElementExtManual::set_state()][crate::gst::prelude::ElementExtManual::set_state()] or [ElementExtManual::sync_state_with_parent()][crate::gst::prelude::ElementExtManual::sync_state_with_parent()].

pad-removed

a gst::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

ChildProxy

child-added

Will be emitted after the object was added to the child_proxy.

child-removed

Will be emitted after the object was removed from the child_proxy.

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

GESTrackExt, [trait@gst::prelude::BinExt], gst::prelude::ElementExt, gst::prelude::GstObjectExt, glib::ObjectExt, gst::prelude::ChildProxyExt, MetaContainerExt

Implementations§

Creates a new track with the given track-type and caps.

If type_ is TrackType::VIDEO, and caps is a subset of “video/x-raw(ANY)”, then a VideoTrack is created. This will automatically choose a gap creation method suitable for video data. You will likely want to set restriction-caps separately. You may prefer to use the VideoTrack::new() method instead.

If type_ is TrackType::AUDIO, and caps is a subset of “audio/x-raw(ANY)”, then a AudioTrack is created. This will automatically choose a gap creation method suitable for audio data, and will set the restriction-caps to the default for AudioTrack. You may prefer to use the AudioTrack::new() method instead.

Otherwise, a plain Track is returned. You will likely want to set the restriction-caps and call ges_track_set_create_element_for_gap_func() on the returned track.

type_

The track-type for the track

caps

The caps for the track

Returns

A new track.

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
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
Emits the child-added signal. Read more
Emits the child-removed signal. Read more
Fetches a child by its number. Read more
Looks up a child element by the given name. Read more
Available on crate feature v1_22 only.
Looks up a child element by the given full-path name. Read more
Gets the number of child objects this parent contains. Read more
Will be emitted after the object was added to the child_proxy. Read more
Will be emitted after the object was removed from the child_proxy. Read more
Looks up which object and GParamSpec would be effected by the given name. Read more
Gets a single property using the GstChildProxy mechanism. You are responsible for freeing it by calling [glib::Value::unset()][crate::glib::Value::unset()] Read more
Sets a single property using the GstChildProxy mechanism. Read more
Abort the state change of the element. This function is used by elements that do asynchronous state changes and find out something is wrong. Read more
Adds a pad (link point) to self. pad’s parent will be set to self; see GstObjectExt::set_parent() for refcounting information. Read more
Perform transition on self. Read more
Commit the state change of the element and proceed to the next pending state if any. This function is used by elements that do asynchronous state changes. The core will normally call this method automatically when an element returned StateChangeReturn::Success from the state change function. Read more
Performs a query on the given element. Read more
Sends an event to an element. If the element doesn’t implement an event handler, the event will be pushed on a random linked sink pad for downstream events or a random linked source pad for upstream events. Read more

Returns the argument unchanged.

Adds the given element to the bin. Sets the element’s parent, and thus takes ownership of the element. An element can only be added to one bin. Read more
Recursively looks for elements with an unlinked pad of the given direction within the specified bin and returns an unlinked pad if one is found, or None otherwise. If a pad is found, the caller owns a reference to it and should use gst_object_unref() on the pad when it is not needed any longer. Read more
Looks for an element inside the bin that implements the given interface. If such an element is found, it returns the element. You can cast this element to the given interface afterwards. If you want all elements that implement the interface, use GstBinExtManual::iterate_all_by_interface(). This function recurses into child bins. Read more
Gets the element with the given name from a bin. This function recurses into child bins. Read more
Gets the element with the given name from this bin. If the element is not found, a recursion is performed on the parent bin. Read more
Returns Read more
Queries self for the current latency and reconfigures this latency on all the elements using a LATENCY event. Read more
Removes the element from the bin, unparenting it as well. Unparenting the element means that the element will be dereferenced, so if the bin holds the only reference to the element, the element will be freed in the process of removing it from the bin. If you want the element to still exist after removing, you need to call gst_object_ref() before removing it from the bin. Read more
Suppresses the given flags on the bin. ElementFlags of a child element are propagated when it is added to the bin. When suppressed flags are set, those specified flags will not be propagated to the bin. Read more
Synchronizes the state of every child of self with the state of self. See also ElementExt::sync_state_with_parent(). Read more
If set to true, the bin will handle asynchronous state changes. This should be used only if the bin subclass is modifying the state of its children on its own.
If set to true, the bin will handle asynchronous state changes. This should be used only if the bin subclass is modifying the state of its children on its own.
Forward all children messages, even those that would normally be filtered by the bin. This can be interesting when one wants to be notified of the EOS state of individual elements, for example. Read more
Forward all children messages, even those that would normally be filtered by the bin. This can be interesting when one wants to be notified of the EOS state of individual elements, for example. Read more
Will be emitted after the element was added to sub_bin. Read more
Will be emitted after the element was removed from sub_bin. Read more
Will be emitted after the element was added to the bin. Read more
Will be emitted after the element was removed from the bin. Read more
Available on crate feature v1_18 only.
Attach the ControlBinding to the object. If there already was a ControlBinding for this property it will be replaced. Read more
A default error function that uses g_printerr() to display the error message and the optional debug string.. Read more
Gets the corresponding ControlBinding for the property. This should be unreferenced again after use. Read more
Obtain the control-rate for this self. Audio processing Element objects will use this rate to sub-divide their processing loop and call sync_values() in between. The length of the processing segment should be up to control-rate nanoseconds. Read more
Returns a copy of the name of self. Caller should g_free() the return value after usage. For a nameless object, this returns None, which you can safely g_free() as well. Read more
Returns the parent of self. This function increases the refcount of the parent object so you should gst_object_unref() it after usage. Read more
Generates a string describing the path of self in the object hierarchy. Only useful (or used) for debugging. Read more
Gets the value for the given controlled property at the requested time. Read more

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.
Returns the type of the object.
Returns the ObjectClass of the object. Read more
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
Returns the strong reference count of this object.
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.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.