Struct AVAsynchronousVideoCompositionRequest 

pub struct AVAsynchronousVideoCompositionRequest { /* private fields */ }

Available on crate feature AVVideoCompositing only.

An AVAsynchronousVideoCompositionRequest instance contains the information necessary for a video compositor to render an output pixel buffer. The video compositor must implement the AVVideoCompositing protocol.

Subclasses of this type that are used from Swift must fulfill the requirements of a Sendable type.

See also Apple’s documentation

Implementations

impl AVAsynchronousVideoCompositionRequest

pub unsafe fn renderContext(&self) -> Retained<AVVideoCompositionRenderContext>

The AVVideoCompositionRenderContext making the request

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn compositionTime(&self) -> CMTime

Available on crate feature objc2-core-media only.

The time for which the frame should be composed

This property is not atomic.

Safety

This might not be thread-safe.

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

Track IDs of all the source video buffers that are available to compose the frame.

This property is not atomic.

Safety

This might not be thread-safe.

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

Track IDs of all the source sample data buffers that are available to compose the frame.

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn videoCompositionInstruction( &self, ) -> Retained<ProtocolObject<dyn AVVideoCompositionInstructionProtocol>>

The AVVideoCompositionInstruction to use to compose the frame.

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn sourceFrameByTrackID( &self, track_id: CMPersistentTrackID, ) -> Option<Retained<CVPixelBuffer>>

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

Returns the source CVPixelBufferRef for the given track ID

If the track contains tagged buffers, a pixel buffer from one of the tagged buffers will be returned.

• Parameter trackID: The track ID for the requested source frame

pub unsafe fn sourceSampleBufferByTrackID( &self, track_id: CMPersistentTrackID, ) -> Option<Retained<CMSampleBuffer>>

Available on crate feature objc2-core-media only.

Returns the source CMSampleBufferRef for the given track ID

• Parameter trackID: The track ID for the requested source sample buffer

pub unsafe fn sourceTimedMetadataByTrackID( &self, track_id: CMPersistentTrackID, ) -> Option<Retained<AVTimedMetadataGroup>>

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

Returns the source AVTimedMetadataGroup * for the given track ID

• Parameter trackID: The track ID for the requested source timed metadata group.

pub unsafe fn finishWithComposedVideoFrame( &self, composed_video_frame: &CVPixelBuffer, )

Available on crate feature objc2-core-video only.

The method that the custom compositor calls when composition succeeds.

• Parameter composedVideoFrame: The video frame to finish with. Call finishWithComposedTaggedBufferGroup: instead if outputBufferDescription is non-nil.

pub unsafe fn finishWithError(&self, error: &NSError)

callback the custom compositor should call when composition failed. The error parameter should describe the actual error.

pub unsafe fn finishCancelledRequest(&self)

callback the custom compositor should call for a request that has been cancelled.

pub unsafe fn sourceTaggedBufferGroupByTrackID( &self, track_id: CMPersistentTrackID, ) -> Option<Retained<CMTaggedBufferGroup>>

Available on crate feature objc2-core-media only.

Returns the source CMTaggedBufferGroupRef for the given track ID.

Returns nil if the video track does not contain tagged buffers. Returns nil if the track does not contain video. This function should only be called when supportsSourceTaggedBuffers is YES.

• Parameter trackID: The track ID for the requested source tagged buffer group.

pub unsafe fn finishWithComposedTaggedBufferGroup( &self, tagged_buffer_group: &CMTaggedBufferGroup, )

Available on crate feature objc2-core-media only.

The method that the custom compositor calls when composition succeeds.

• Parameter taggedBufferGroup: The tagged buffer group containing the composed tagged buffers. The tagged buffers must be compatible with the outputBufferDescription specified in the video composition. The outputBufferDescription must not be nil when calling this function. NOTE: If AVVideoComposition/spatialConfigurations is not empty, then attach(spatialVideoConfiguration:to:) must be called with one of the spatial configurations. An exception will be thrown otherwise. Also, all pixel buffers must be associated with the same spatial configuration. An exception will be thrown otherwise.

pub unsafe fn attachSpatialVideoConfiguration_toPixelBuffer( &self, spatial_video_configuration: Option<&AVSpatialVideoConfiguration>, pixel_buffer: &CVPixelBuffer, )

Available on crate features AVSpatialVideoConfiguration and objc2-core-video only.

Associates the pixel buffer with the specified spatial configuration.

• Parameters:
• spatialVideoConfiguration: The spatial configuration to associate with the pixel buffer.
• pixelBuffer: The pixel buffer to associate with the spatial configuration. NOTE: The spatial configuration must be one of the spatial configurations specified in the AVVideoComposition/spatialConfigurations property. An exception will be thrown otherwise. NOTE: All pixel buffers from the custom compositor must be associated with the same spatial configuration. An exception will be thrown otherwise. A spatial configuration with all nil values indicates the video is not spatial. A nil spatial configuration also indicates the video is not spatial. The value can be nil, which indicates the output will not be spatial, but a spatial configuration with all nil values must be in the AVVideoComposition/spatialConfigurations property or an exception will be thrown.

impl AVAsynchronousVideoCompositionRequest

Methods declared on superclass NSObject.

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

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

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 AsRef<AVAsynchronousVideoCompositionRequest> for AVAsynchronousVideoCompositionRequest

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVAsynchronousVideoCompositionRequest

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVAsynchronousVideoCompositionRequest

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for AVAsynchronousVideoCompositionRequest

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVAsynchronousVideoCompositionRequest

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVAsynchronousVideoCompositionRequest

const NAME: &'static str = "AVAsynchronousVideoCompositionRequest"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVAsynchronousVideoCompositionRequest 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 AVAsynchronousVideoCompositionRequest

type Result = AVAsynchronousVideoCompositionRequest

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

impl Debug for AVAsynchronousVideoCompositionRequest

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

Formats the value using the given formatter.

impl Deref for AVAsynchronousVideoCompositionRequest

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVAsynchronousVideoCompositionRequest

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 AVAsynchronousVideoCompositionRequest

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSCopying for AVAsynchronousVideoCompositionRequest

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 AVAsynchronousVideoCompositionRequest

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 AVAsynchronousVideoCompositionRequest

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 AVAsynchronousVideoCompositionRequest

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

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

impl DowncastTarget for AVAsynchronousVideoCompositionRequest

impl Eq for AVAsynchronousVideoCompositionRequest

impl Send for AVAsynchronousVideoCompositionRequest

impl Sync for AVAsynchronousVideoCompositionRequest