Struct AVCompositionTrack 

pub struct AVCompositionTrack { /* private fields */ }

Available on crate features AVAssetTrack and AVCompositionTrack only.

Apple’s documentation

Implementations

impl AVCompositionTrack

pub unsafe fn segments(&self) -> Retained<NSArray<AVCompositionTrackSegment>>

Available on crate features AVAssetTrackSegment and AVCompositionTrackSegment only.

Provides read-only access to the array of track segments, each an instance of AVCompositionTrackSegment.

Note that timeMapping.target.start of the first AVCompositionTrackSegment must be kCMTimeZero, and the timeMapping.target.start of each subsequent AVCompositionTrackSegment must equal CMTimeRangeGetEnd(the previous AVCompositionTrackSegment’s timeMapping.target). Use -validateTrackSegments:error: to perform a test to ensure that an array of AVCompositionTrackSegments conforms to this rule.

pub unsafe fn segmentForTrackTime( &self, track_time: CMTime, ) -> Option<Retained<AVCompositionTrackSegment>>

Available on crate features AVAssetTrackSegment and AVCompositionTrackSegment and objc2-core-media only.

Supplies the AVCompositionTrackSegment from the segments array with a target timeRange that either contains the specified track time or is the closest to it among the target timeRanges of the track’s segments.

Parameter trackTime: The trackTime for which an AVCompositionTrackSegment is requested.

Returns: An AVCompositionTrackSegment.

If the trackTime does not map to a sample presentation time (e.g. it’s outside the track’s timeRange), the segment closest in time to the specified trackTime is returned.

pub unsafe fn formatDescriptionReplacements( &self, ) -> Retained<NSArray<AVCompositionTrackFormatDescriptionReplacement>>

An array of AVCompositionTrackFormatDescriptionReplacement objects indicating original format descriptions and their replacements.

The value of this property is an array of AVCompositionTrackFormatDescriptionReplacement objects, each of which specifies an original format description together with its replacement format description (as specified by a previous call to -replaceFormatDescription:withFormatDescription:). Only format descriptions that are to be replaced will occur as the originalFormatDescription elements in the AVCompositionTrackFormatDescriptionReplacement objects in this array.

impl AVCompositionTrack

Methods declared on superclass AVAssetTrack.

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

pub unsafe fn new() -> Retained<Self>

impl AVCompositionTrack

SynchronousTrackInterface.

Redeclarations of async-only AVAssetTrack interfaces to allow synchronous usage in the synchronous subclass.

See AVAssetTrack’s interface for more information about these interfaces.

pub unsafe fn hasMediaCharacteristic( &self, media_characteristic: &AVMediaCharacteristic, ) -> bool

Available on crate feature AVMediaFormat only.

pub unsafe fn samplePresentationTimeForTrackTime( &self, track_time: CMTime, ) -> CMTime

Available on crate feature objc2-core-media only.

pub unsafe fn metadataForFormat( &self, format: &AVMetadataFormat, ) -> Retained<NSArray<AVMetadataItem>>

Available on crate features AVMetadataFormat and AVMetadataItem only.

pub unsafe fn associatedTracksOfType( &self, track_association_type: &AVTrackAssociationType, ) -> Retained<NSArray<AVAssetTrack>>

Methods from Deref<Target = AVAssetTrack>

pub unsafe fn asset(&self) -> Option<Retained<AVAsset>>

Available on crate feature AVAsset only.

Provides a reference to the AVAsset of which the AVAssetTrack is a part

pub unsafe fn trackID(&self) -> CMPersistentTrackID

Available on crate feature objc2-core-media only.

Indicates the persistent unique identifier for this track of the asset

pub unsafe fn mediaType(&self) -> Retained<AVMediaType>

Available on crate feature AVMediaFormat only.

Indicates the media type for this track, e.g. AVMediaTypeVideo, AVMediaTypeAudio, etc., as defined in AVMediaFormat.h.

pub unsafe fn formatDescriptions(&self) -> Retained<NSArray>

Provides an array of CMFormatDescriptions each of which indicates the format of media samples referenced by the track; a track that presents uniform media, e.g. encoded according to the same encoding settings, will provide an array with a count of 1.

pub unsafe fn isPlayable(&self) -> bool

Indicates whether the receiver is playable in the current environment; if YES, an AVPlayerItemTrack of an AVPlayerItem initialized with the receiver’s asset can be enabled for playback.

pub unsafe fn isDecodable(&self) -> bool

Indicates whether the receiver is decodable in the current environment; if YES, the track can be decoded even though decoding may be too slow for real time playback.

pub unsafe fn isEnabled(&self) -> bool

Indicates whether the track is enabled according to state stored in its container or construct; note that its presentation state can be changed from this default via AVPlayerItemTrack

pub unsafe fn isSelfContained(&self) -> bool

Indicates whether the track references sample data only within its storage container

pub unsafe fn totalSampleDataLength(&self) -> c_longlong

Indicates the total number of bytes of sample data required by the track

pub unsafe fn hasMediaCharacteristic( &self, media_characteristic: &AVMediaCharacteristic, ) -> bool

Available on crate feature AVMediaFormat only.

Reports whether the track references media with the specified media characteristic.

• Parameter mediaCharacteristic: The media characteristic of interest, e.g. AVMediaCharacteristicVisual, AVMediaCharacteristicAudible, AVMediaCharacteristicLegible, etc., as defined above.

• Returns: YES if the track references media with the specified characteristic, otherwise NO.

pub unsafe fn timeRange(&self) -> CMTimeRange

Available on crate feature objc2-core-media only.

Indicates the timeRange of the track within the overall timeline of the asset; a track with CMTIME_COMPARE_INLINE(timeRange.start, >, kCMTimeZero) will initially present an empty interval.

pub unsafe fn naturalTimeScale(&self) -> CMTimeScale

Available on crate feature objc2-core-media only.

Indicates a timescale in which time values for the track can be operated upon without extraneous numerical conversion

pub unsafe fn estimatedDataRate(&self) -> c_float

Indicates the estimated data rate of the media data referenced by the track, in units of bits per second

pub unsafe fn languageCode(&self) -> Option<Retained<NSString>>

Indicates the language associated with the track, as an ISO 639-2/T language code; may be nil if no language is indicated

pub unsafe fn extendedLanguageTag(&self) -> Option<Retained<NSString>>

Indicates the language tag associated with the track, as an IETF BCP 47 (RFC 4646) language identifier; may be nil if no language tag is indicated

pub unsafe fn naturalSize(&self) -> CGSize

Available on crate feature objc2-core-foundation only.

Indicates the natural dimensions of the media data referenced by the track as a CGSize

pub unsafe fn preferredTransform(&self) -> CGAffineTransform

Available on crate feature objc2-core-foundation only.

Indicates the transform specified in the track’s storage container as the preferred transformation of the visual media data for display purposes; its value is often but not always CGAffineTransformIdentity

pub unsafe fn preferredVolume(&self) -> c_float

Indicates the volume specified in the track’s storage container as the preferred volume of the audible media data

pub unsafe fn hasAudioSampleDependencies(&self) -> bool

Indicates whether this audio track has dependencies (e.g. kAudioFormatMPEGD_USAC)

pub unsafe fn nominalFrameRate(&self) -> c_float

For tracks that carry a full frame per media sample, indicates the frame rate of the track in units of frames per second.

For field-based video tracks that carry one field per media sample, the value of this property is the field rate, not the frame rate.

pub unsafe fn minFrameDuration(&self) -> CMTime

Available on crate feature objc2-core-media only.

Indicates the minimum duration of the track’s frames; the value will be kCMTimeInvalid if the minimum frame duration is not known or cannot be calculated

pub unsafe fn requiresFrameReordering(&self) -> bool

Indicates whether samples in the track may have different values for their presentation and decode timestamps.

pub unsafe fn segments(&self) -> Retained<NSArray<AVAssetTrackSegment>>

Available on crate feature AVAssetTrackSegment only.

Provides an array of AVAssetTrackSegments with time mappings from the timeline of the track’s media samples to the timeline of the track. Empty edits, i.e. timeRanges for which no media data is available to be presented, have a value of AVAssetTrackSegment.empty equal to YES.

pub unsafe fn segmentForTrackTime( &self, track_time: CMTime, ) -> Option<Retained<AVAssetTrackSegment>>

👎Deprecated: Use loadSegmentForTrackTime:completionHandler: instead

Available on crate features AVAssetTrackSegment and objc2-core-media only.

Supplies the AVAssetTrackSegment from the segments array with a target timeRange that either contains the specified track time or is the closest to it among the target timeRanges of the track’s segments.

If the trackTime does not map to a sample presentation time (e.g. it’s outside the track’s timeRange), the segment closest in time to the specified trackTime is returned.

• Parameter trackTime: The trackTime for which an AVAssetTrackSegment is requested.

• Returns: An AVAssetTrackSegment.

pub unsafe fn loadSegmentForTrackTime_completionHandler( &self, track_time: CMTime, completion_handler: &DynBlock<dyn Fn(*mut AVAssetTrackSegment, *mut NSError)>, )

Available on crate features AVAssetTrackSegment and block2 and objc2-core-media only.

Loads the AVAssetTrackSegment from the segments array with a target timeRange that either contains the specified track time or is the closest to it among the target timeRanges of the track’s segments.

If the trackTime does not map to a sample presentation time (e.g. it’s outside the track’s timeRange), the segment closest in time to the specified trackTime is returned.

• Parameter trackTime: The trackTime for which an AVAssetTrackSegment is requested.
• Parameter completionHandler: A block that is invoked when loading is complete, vending an AVAssetTrackSegment or an error.

Safety

completion_handler block must be sendable.

pub unsafe fn samplePresentationTimeForTrackTime( &self, track_time: CMTime, ) -> CMTime

👎Deprecated: Use loadSamplePresentationTimeForTrackTime:completionHandler: instead

Available on crate feature objc2-core-media only.

Maps the specified trackTime through the appropriate time mapping and returns the resulting sample presentation time.

• Parameter trackTime: The trackTime for which a sample presentation time is requested.

• Returns: A CMTime; will be invalid if the trackTime is out of range

pub unsafe fn loadSamplePresentationTimeForTrackTime_completionHandler( &self, track_time: CMTime, completion_handler: &DynBlock<dyn Fn(CMTime, *mut NSError)>, )

Available on crate features block2 and objc2-core-media only.

Maps the specified trackTime through the appropriate time mapping and loads the resulting sample presentation time.

• Parameter trackTime: The trackTime for which a sample presentation time is requested.
• Parameter completionHandler: A block that is invoked when loading is complete, vending a CMTime (which will be invalid if the trackTime is out of range) or an error.

Safety

completion_handler block must be sendable.

pub unsafe fn commonMetadata(&self) -> Retained<NSArray<AVMetadataItem>>

Available on crate feature AVMetadataItem only.

Provides access to an array of AVMetadataItems for each common metadata key for which a value is available

pub unsafe fn metadata(&self) -> Retained<NSArray<AVMetadataItem>>

Available on crate feature AVMetadataItem only.

Provides access to an array of AVMetadataItems for all metadata identifiers for which a value is available; items can be filtered according to language via +[AVMetadataItem metadataItemsFromArray:filteredAndSortedAccordingToPreferredLanguages:] and according to identifier via +[AVMetadataItem metadataItemsFromArray:filteredByIdentifier:].

pub unsafe fn availableMetadataFormats( &self, ) -> Retained<NSArray<AVMetadataFormat>>

Available on crate feature AVMetadataFormat only.

Provides an NSArray of NSStrings, each representing a format of metadata that’s available for the track (e.g. QuickTime userdata, etc.) Metadata formats are defined in AVMetadataItem.h.

pub unsafe fn metadataForFormat( &self, format: &AVMetadataFormat, ) -> Retained<NSArray<AVMetadataItem>>

👎Deprecated: Use loadMetadataForFormat:completionHandler: instead

Available on crate features AVMetadataFormat and AVMetadataItem only.

Provides an NSArray of AVMetadataItems, one for each metadata item in the container of the specified format.

Becomes callable without blocking when the key “ availableMetadataFormats“ has been loaded

• Parameter format: The metadata format for which items are requested.

• Returns: An NSArray containing AVMetadataItems.

pub unsafe fn loadMetadataForFormat_completionHandler( &self, format: &AVMetadataFormat, completion_handler: &DynBlock<dyn Fn(*mut NSArray<AVMetadataItem>, *mut NSError)>, )

Available on crate features AVMetadataFormat and AVMetadataItem and block2 only.

Loads an NSArray of AVMetadataItems, one for each metadata item in the container of the specified format.

• Parameter format: The metadata format for which items are requested.
• Parameter completionHandler: A block that is invoked when loading is complete, vending the array of metadata items (which may be empty if there is no metadata of the specified format) or an error.

Safety

completion_handler block must be sendable.

pub unsafe fn availableTrackAssociationTypes( &self, ) -> Retained<NSArray<AVTrackAssociationType>>

Provides an NSArray of NSStrings, each representing a type of track association that the receiver has with one or more of the other tracks of the asset (e.g. AVTrackAssociationTypeChapterList, AVTrackAssociationTypeTimecode, etc.). Track association types are defined immediately above.

pub unsafe fn associatedTracksOfType( &self, track_association_type: &AVTrackAssociationType, ) -> Retained<NSArray<AVAssetTrack>>

👎Deprecated: Use loadAssociatedTracksOfType:completionHandler: instead

Provides an NSArray of AVAssetTracks, one for each track associated with the receiver with the specified type of track association.

Becomes callable without blocking when the key “ availableTrackAssociationTypes“ has been loaded.

• Parameter trackAssociationType: The type of track association for which associated tracks are requested.

• Returns: An NSArray containing AVAssetTracks; may be empty if there is no associated tracks of the specified type.

pub unsafe fn loadAssociatedTracksOfType_completionHandler( &self, track_association_type: &AVTrackAssociationType, completion_handler: &DynBlock<dyn Fn(*mut NSArray<AVAssetTrack>, *mut NSError)>, )

Available on crate feature block2 only.

Provides an NSArray of AVAssetTracks, one for each track associated with the receiver with the specified type of track association.

• Parameter trackAssociationType: The type of track association for which associated tracks are requested.
• Parameter completionHandler: A block that is invoked when loading is comlete, vending an array of tracks (which may be empty if there is no associated tracks of the specified type) or an error. `

Safety

completion_handler block must be sendable.

pub unsafe fn canProvideSampleCursors(&self) -> bool

Indicates whether the receiver can provide instances of AVSampleCursor for traversing its media samples and discovering information about them.

pub unsafe fn makeSampleCursorWithPresentationTimeStamp( &self, presentation_time_stamp: CMTime, ) -> Option<Retained<AVSampleCursor>>

Available on crate features AVSampleCursor and objc2-core-media only.

Creates an instance of AVSampleCursor and positions it at or near the specified presentation timestamp.

If the receiver’s asset has a value of YES for providesPreciseDurationAndTiming, the sample cursor will be accurately positioned at the receiver’s last media sample with presentation timestamp less than or equal to the desired timestamp, or, if there are no such samples, the first sample in presentation order. If the receiver’s asset has a value of NO for providesPreciseDurationAndTiming, and it is prohibitively expensive to locate the precise sample at the desired timestamp, the sample cursor may be approximately positioned. This method will return nil if there are no samples in the track.

• Parameter presentationTimeStamp: The desired initial presentation timestamp of the returned AVSampleCursor.

• Returns: An instance of AVSampleCursor.

pub unsafe fn makeSampleCursorAtFirstSampleInDecodeOrder( &self, ) -> Option<Retained<AVSampleCursor>>

Available on crate feature AVSampleCursor only.

Creates an instance of AVSampleCursor and positions it at the receiver’s first media sample in decode order.

This method will return nil if there are no samples in the track.

• Returns: An instance of AVSampleCursor.

pub unsafe fn makeSampleCursorAtLastSampleInDecodeOrder( &self, ) -> Option<Retained<AVSampleCursor>>

Available on crate feature AVSampleCursor only.

Creates an instance of AVSampleCursor and positions it at the receiver’s last media sample in decode order.

This method will return nil if there are no samples in the track.

• Returns: An instance of AVSampleCursor.

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}

Trait Implementations

impl AVAsynchronousKeyValueLoading for AVCompositionTrack

unsafe fn loadValuesAsynchronouslyForKeys_completionHandler( &self, keys: &NSArray<NSString>, handler: Option<&DynBlock<dyn Fn()>>, )

where Self: Sized + Message,

Available on crate features AVAsynchronousKeyValueLoading and block2 only.

Directs the target to load the values of any of the specified keys that are not already loaded.

impl AsRef<AVAssetTrack> for AVCompositionTrack

fn as_ref(&self) -> &AVAssetTrack

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AVCompositionTrack> for AVCompositionTrack

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AVCompositionTrack> for AVMutableCompositionTrack

fn as_ref(&self) -> &AVCompositionTrack

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AnyObject> for AVCompositionTrack

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for AVCompositionTrack

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AVAssetTrack> for AVCompositionTrack

fn borrow(&self) -> &AVAssetTrack

Immutably borrows from an owned value.

impl Borrow<AVCompositionTrack> for AVMutableCompositionTrack

fn borrow(&self) -> &AVCompositionTrack

Immutably borrows from an owned value.

impl Borrow<AnyObject> for AVCompositionTrack

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVCompositionTrack

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVCompositionTrack

const NAME: &'static str = "AVCompositionTrack"

The name of the Objective-C class that this type represents.

type Super = AVAssetTrack

The superclass of this class.

type ThreadKind = <<AVCompositionTrack as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl CopyingHelper for AVCompositionTrack

type Result = AVCompositionTrack

The immutable counterpart of the type, or Self if the type has no immutable counterpart.

impl Debug for AVCompositionTrack

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

Formats the value using the given formatter.

impl Deref for AVCompositionTrack

type Target = AVAssetTrack

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for AVCompositionTrack

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

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 Message for AVCompositionTrack

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSCopying for AVCompositionTrack

fn copy(&self) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

unsafe fn copyWithZone(&self, zone: *mut NSZone) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

impl NSObjectProtocol for AVCompositionTrack

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for AVCompositionTrack

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl RefEncode for AVCompositionTrack

const ENCODING_REF: Encoding = <AVAssetTrack as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for AVCompositionTrack

impl Eq for AVCompositionTrack