Struct AVVideoCompositionInstruction 

pub struct AVVideoCompositionInstruction { /* private fields */ }

Available on crate feature AVVideoComposition only.

An AVVideoCompositionInstruction object represents an operation to be performed by a compositor.

An AVVideoComposition object maintains an array of instructions to perform its composition. This class is not intended to be subclassed; instead, conform to AVVideoCompositionInstructionProtocol (“AVVideoCompositionInstruction” in Objective-C). Subclasses of this type that are used from Swift must fulfill the requirements of a Sendable type.

See also Apple’s documentation

Implementations

impl AVVideoCompositionInstruction

pub unsafe fn videoCompositionInstructionWithInstruction( instruction: &AVVideoCompositionInstruction, ) -> Retained<AVVideoCompositionInstruction>

Pass-through initializer, for internal use in AVFoundation only

pub unsafe fn timeRange(&self) -> CMTimeRange

Available on crate feature objc2-core-media only.

Indicates the timeRange during which the instruction is effective. Note requirements for the timeRanges of instructions described in connection with AVVideoComposition’s instructions key above.

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn backgroundColor(&self) -> Option<Retained<CGColor>>

Available on crate feature objc2-core-graphics only.

Indicates the background color of the composition.

Solid BGRA colors only are supported; patterns and other color refs that are not supported will be ignored.

• If the background color is not specified the video compositor will use a default backgroundColor of opaque black.
• If the rendered pixel buffer does not have alpha, the alpha value of the backgroundColor will be ignored.

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn layerInstructions( &self, ) -> Retained<NSArray<AVVideoCompositionLayerInstruction>>

Provides an array of instances of AVVideoCompositionLayerInstruction that specify how video frames from source tracks should be layered and composed.

Tracks are layered in the composition according to the top-to-bottom order of the layerInstructions array; the track with trackID of the first instruction in the array will be layered on top, with the track with the trackID of the second instruction immediately underneath, etc. If this key is nil, the output will be a fill of the background color.

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn enablePostProcessing(&self) -> bool

If NO, indicates that post-processing should be skipped for the duration of this instruction. YES by default.

See +[AVVideoCompositionCoreAnimationTool videoCompositionToolWithPostProcessingAsVideoLayer:inLayer:].

This property is not atomic.

Safety

This might not be thread-safe.

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

List of video track IDs required to compose frames for this instruction. The value of this property is computed from the layer instructions.

This property is not atomic.

Safety

This might not be thread-safe.

pub unsafe fn passthroughTrackID(&self) -> CMPersistentTrackID

Available on crate feature objc2-core-media only.

If the video composition result is one of the source frames for the duration of the instruction, this property returns the corresponding track ID. The compositor won’t be run for the duration of the instruction and the proper source frame will be used instead. The value of this property is computed from the layer instructions

This property is not atomic.

Safety

This might not be thread-safe.

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

List of track IDs for which sample data should be presented to the compositor for this instruction.

This property is not atomic.

Safety

This might not be thread-safe.

impl AVVideoCompositionInstruction

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 AVVideoCompositionInstructionProtocol for AVVideoCompositionInstruction

unsafe fn timeRange(&self) -> CMTimeRange

where Self: Sized + Message,

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

Indicates the timeRange during which the instruction is effective. Note requirements for the timeRanges of instructions described in connection with AVVideoComposition’s instructions key above.

unsafe fn enablePostProcessing(&self) -> bool

where Self: Sized + Message,

Available on crate feature AVVideoCompositing only.

If NO, indicates that post-processing should be skipped for the duration of this instruction. See +[AVVideoCompositionCoreAnimationTool videoCompositionToolWithPostProcessingAsVideoLayer:inLayer:].

unsafe fn containsTweening(&self) -> bool

where Self: Sized + Message,

Available on crate feature AVVideoCompositing only.

If YES, rendering a frame from the same source buffers and the same composition instruction at 2 different compositionTime may yield different output frames. If NO, 2 such compositions would yield the same frame. The media pipeline may be able to avoid some duplicate processing when containsTweening is NO

unsafe fn requiredSourceTrackIDs(&self) -> Option<Retained<NSArray<NSValue>>>

where Self: Sized + Message,

Available on crate feature AVVideoCompositing only.

List of video track IDs required to compose frames for this instruction. If the value of this property is nil, all source tracks will be considered required for composition

unsafe fn passthroughTrackID(&self) -> CMPersistentTrackID

where Self: Sized + Message,

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

If for the duration of the instruction, the video composition result is one of the source frames, this property should return the corresponding track ID. The compositor won’t be run for the duration of the instruction and the proper source frame will be used instead. The dimensions, clean aperture and pixel aspect ratio of the source buffer will be matched to the required values automatically

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

where Self: Sized + Message,

Available on crate feature AVVideoCompositing only.

List of sample data track IDs required to compose frames for this instruction. An empty array indicates that no sample data is required for this instruction.

impl AsRef<AVVideoCompositionInstruction> for AVMutableVideoCompositionInstruction

fn as_ref(&self) -> &AVVideoCompositionInstruction

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

impl AsRef<AVVideoCompositionInstruction> for AVVideoCompositionInstruction

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVVideoCompositionInstruction

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVVideoCompositionInstruction

fn as_ref(&self) -> &NSObject

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

impl Borrow<AVVideoCompositionInstruction> for AVMutableVideoCompositionInstruction

fn borrow(&self) -> &AVVideoCompositionInstruction

Immutably borrows from an owned value.

impl Borrow<AnyObject> for AVVideoCompositionInstruction

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVVideoCompositionInstruction

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVVideoCompositionInstruction

const NAME: &'static str = "AVVideoCompositionInstruction"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVVideoCompositionInstruction 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 AVVideoCompositionInstruction

type Result = AVVideoCompositionInstruction

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

impl Debug for AVVideoCompositionInstruction

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

Formats the value using the given formatter.

impl Deref for AVVideoCompositionInstruction

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVVideoCompositionInstruction

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 AVVideoCompositionInstruction

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

where Self: Sized,

Increment the reference count of the receiver.

impl MutableCopyingHelper for AVVideoCompositionInstruction

type Result = AVMutableVideoCompositionInstruction

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

impl NSCoding for AVVideoCompositionInstruction

unsafe fn encodeWithCoder(&self, coder: &NSCoder)

where Self: Sized + Message,

Safety

unsafe fn initWithCoder( this: Allocated<Self>, coder: &NSCoder, ) -> Option<Retained<Self>>

where Self: Sized + Message,

Safety

impl NSCopying for AVVideoCompositionInstruction

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 NSMutableCopying for AVVideoCompositionInstruction

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

where Self: Sized + Message + MutableCopyingHelper,

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

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

where Self: Sized + Message + MutableCopyingHelper,

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

impl NSObjectProtocol for AVVideoCompositionInstruction

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 NSSecureCoding for AVVideoCompositionInstruction

fn supportsSecureCoding() -> bool

where Self: Sized + ClassType,

impl PartialEq for AVVideoCompositionInstruction

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 AVVideoCompositionInstruction

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

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

impl DowncastTarget for AVVideoCompositionInstruction

impl Eq for AVVideoCompositionInstruction

impl Send for AVVideoCompositionInstruction

impl Sync for AVVideoCompositionInstruction