AVCaptureOutput

Struct AVCaptureOutput 

Source
pub struct AVCaptureOutput { /* private fields */ }
Available on crate feature AVCaptureOutputBase only.
Expand description

AVCaptureOutput is an abstract class that defines an interface for an output destination of an AVCaptureSession.

AVCaptureOutput provides an abstract interface for connecting capture output destinations, such as files and video previews, to an AVCaptureSession.

An AVCaptureOutput can have multiple connections represented by AVCaptureConnection objects, one for each stream of media that it receives from an AVCaptureInput. An AVCaptureOutput does not have any connections when it is first created. When an output is added to an AVCaptureSession, connections are created that map media data from that session’s inputs to its outputs.

Concrete AVCaptureOutput instances can be added to an AVCaptureSession using the -[AVCaptureSession addOutput:] and -[AVCaptureSession addOutputWithNoConnections:] methods.

See also Apple’s documentation

Implementations§

Source§

impl AVCaptureOutput

Source

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

Source

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

Source

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

Available on crate feature AVCaptureSession only.

The connections that describe the flow of media data to the receiver from AVCaptureInputs.

The value of this property is an NSArray of AVCaptureConnection objects, each describing the mapping between the receiver and the AVCaptureInputPorts of one or more AVCaptureInputs.

Source

pub unsafe fn connectionWithMediaType( &self, media_type: &AVMediaType, ) -> Option<Retained<AVCaptureConnection>>

Available on crate features AVCaptureSession and AVMediaFormat only.

Returns the first connection in the connections array with an inputPort of the specified mediaType.

Parameter mediaType: An AVMediaType constant from AVMediaFormat.h, e.g. AVMediaTypeVideo.

This convenience method returns the first AVCaptureConnection in the receiver’s connections array that has an AVCaptureInputPort of the specified mediaType. If no connection with the specified mediaType is found, nil is returned.

Source

pub unsafe fn transformedMetadataObjectForMetadataObject_connection( &self, metadata_object: &AVMetadataObject, connection: &AVCaptureConnection, ) -> Option<Retained<AVMetadataObject>>

Available on crate features AVCaptureSession and AVMetadataObject only.

Converts an AVMetadataObject’s visual properties to the receiver’s coordinates.

Parameter metadataObject: An AVMetadataObject originating from the same AVCaptureInput as the receiver.

Parameter connection: The receiver’s connection whose AVCaptureInput matches that of the metadata object to be converted.

Returns: An AVMetadataObject whose properties are in output coordinates.

AVMetadataObject bounds may be expressed as a rect where {0,0} represents the top left of the picture area, and {1,1} represents the bottom right on an unrotated picture. Face metadata objects likewise express yaw and roll angles with respect to an unrotated picture. -transformedMetadataObjectForMetadataObject:connection: converts the visual properties in the coordinate space of the supplied AVMetadataObject to the coordinate space of the receiver. The conversion takes orientation, mirroring, and scaling into consideration. If the provided metadata object originates from an input source other than the preview layer’s, nil will be returned.

If an AVCaptureVideoDataOutput instance’s connection’s videoOrientation or videoMirrored properties are set to non-default values, the output applies the desired mirroring and orientation by physically rotating and or flipping sample buffers as they pass through it. AVCaptureStillImageOutput, on the other hand, does not physically rotate its buffers. It attaches an appropriate kCGImagePropertyOrientation number to captured still image buffers (see ImageIO/CGImageProperties.h) indicating how the image should be displayed on playback. Likewise, AVCaptureMovieFileOutput does not physically apply orientation/mirroring to its sample buffers – it uses a QuickTime track matrix to indicate how the buffers should be rotated and/or flipped on playback.

transformedMetadataObjectForMetadataObject:connection: alters the visual properties of the provided metadata object to match the physical rotation / mirroring of the sample buffers provided by the receiver through the indicated connection. I.e., for video data output, adjusted metadata object coordinates are rotated/mirrored. For still image and movie file output, they are not.

Source

pub unsafe fn metadataOutputRectOfInterestForRect( &self, rect_in_output_coordinates: CGRect, ) -> CGRect

Available on crate feature objc2-core-foundation only.

Converts a rectangle in the receiver’s coordinate space to a rectangle of interest in the coordinate space of an AVCaptureMetadataOutput whose capture device is providing input to the receiver.

Parameter rectInOutputCoordinates: A CGRect in the receiver’s coordinates.

Returns: A CGRect in the coordinate space of the metadata output whose capture device is providing input to the receiver.

AVCaptureMetadataOutput rectOfInterest is expressed as a CGRect where {0,0} represents the top left of the picture area, and {1,1} represents the bottom right on an unrotated picture. This convenience method converts a rectangle in the coordinate space of the receiver to a rectangle of interest in the coordinate space of an AVCaptureMetadataOutput whose AVCaptureDevice is providing input to the receiver. The conversion takes orientation, mirroring, and scaling into consideration. See -transformedMetadataObjectForMetadataObject:connection: for a full discussion of how orientation and mirroring are applied to sample buffers passing through the output.

Source

pub unsafe fn rectForMetadataOutputRectOfInterest( &self, rect_in_metadata_output_coordinates: CGRect, ) -> CGRect

Available on crate feature objc2-core-foundation only.

Converts a rectangle of interest in the coordinate space of an AVCaptureMetadataOutput whose capture device is providing input to the receiver to a rectangle in the receiver’s coordinates.

Parameter rectInMetadataOutputCoordinates: A CGRect in the coordinate space of the metadata output whose capture device is providing input to the receiver.

Returns: A CGRect in the receiver’s coordinates.

AVCaptureMetadataOutput rectOfInterest is expressed as a CGRect where {0,0} represents the top left of the picture area, and {1,1} represents the bottom right on an unrotated picture. This convenience method converts a rectangle in the coordinate space of an AVCaptureMetadataOutput whose AVCaptureDevice is providing input to the coordinate space of the receiver. The conversion takes orientation, mirroring, and scaling into consideration. See -transformedMetadataObjectForMetadataObject:connection: for a full discussion of how orientation and mirroring are applied to sample buffers passing through the output.

Source

pub unsafe fn isDeferredStartSupported(&self) -> bool

A BOOL value that indicates whether the output supports deferred start.

You can only set the deferredStartEnabled property value to true if the output supports deferred start.

Source

pub unsafe fn isDeferredStartEnabled(&self) -> bool

A BOOL value that indicates whether to defer starting this capture output.

When this value is true, the session does not prepare the output’s resources until some time after AVCaptureSession/startRunning returns. You can start the visual parts of your user interface (e.g. preview) prior to other parts (e.g. photo/movie capture, metadata output, etc..) to improve startup performance. Set this value to false for outputs that your app needs for startup, and true for the ones it does not need to start immediately. For example, an AVCaptureVideoDataOutput that you intend to use for displaying preview should set this value to false, so that the frames are available as soon as possible.

By default, for apps that are linked on or after iOS 26, this property value is true for AVCapturePhotoOutput and AVCaptureFileOutput subclasses if supported, and false otherwise. When set to true for AVCapturePhotoOutput, if you want to support multiple capture requests before running deferred start, set AVCapturePhotoOutput/responsiveCaptureEnabled to true on that output.

If deferredStartSupported is false, setting this property value to true results in the system throwing an NSInvalidArgumentException.

  • Note: Set this value before calling AVCaptureSession/commitConfiguration as it requires a lengthy reconfiguration of the capture render pipeline.
Source

pub unsafe fn setDeferredStartEnabled(&self, deferred_start_enabled: bool)

Methods from Deref<Target = NSObject>§

Source

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

Source

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());
Source

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.

Source

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§

Source§

impl AsRef<AVCaptureOutput> for AVCaptureAudioDataOutput

Available on crate feature AVCaptureAudioDataOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureAudioFileOutput

Available on crate feature AVCaptureFileOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureAudioPreviewOutput

Available on crate feature AVCaptureAudioPreviewOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureDepthDataOutput

Available on crate feature AVCaptureDepthDataOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureFileOutput

Available on crate feature AVCaptureFileOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureMetadataOutput

Available on crate feature AVCaptureMetadataOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureMovieFileOutput

Available on crate feature AVCaptureFileOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureOutput

Source§

fn as_ref(&self) -> &Self

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

impl AsRef<AVCaptureOutput> for AVCapturePhotoOutput

Available on crate feature AVCapturePhotoOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureStillImageOutput

Available on crate feature AVCaptureStillImageOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureVideoDataOutput

Available on crate feature AVCaptureVideoDataOutput only.
Source§

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AnyObject> for AVCaptureOutput

Source§

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVCaptureOutput

Source§

fn as_ref(&self) -> &NSObject

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

impl Borrow<AVCaptureOutput> for AVCaptureAudioDataOutput

Available on crate feature AVCaptureAudioDataOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureAudioFileOutput

Available on crate feature AVCaptureFileOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureAudioPreviewOutput

Available on crate feature AVCaptureAudioPreviewOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureDepthDataOutput

Available on crate feature AVCaptureDepthDataOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureFileOutput

Available on crate feature AVCaptureFileOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureMetadataOutput

Available on crate feature AVCaptureMetadataOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureMovieFileOutput

Available on crate feature AVCaptureFileOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCapturePhotoOutput

Available on crate feature AVCapturePhotoOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureStillImageOutput

Available on crate feature AVCaptureStillImageOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AVCaptureOutput> for AVCaptureVideoDataOutput

Available on crate feature AVCaptureVideoDataOutput only.
Source§

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value. Read more
Source§

impl Borrow<AnyObject> for AVCaptureOutput

Source§

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value. Read more
Source§

impl Borrow<NSObject> for AVCaptureOutput

Source§

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value. Read more
Source§

impl ClassType for AVCaptureOutput

Source§

const NAME: &'static str = "AVCaptureOutput"

The name of the Objective-C class that this type represents. Read more
Source§

type Super = NSObject

The superclass of this class. Read more
Source§

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

Whether the type can be used from any thread, or from only the main thread. Read more
Source§

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents. Read more
Source§

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

Get an immutable reference to the superclass.
Source§

impl Debug for AVCaptureOutput

Source§

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

Formats the value using the given formatter. Read more
Source§

impl Deref for AVCaptureOutput

Source§

type Target = NSObject

The resulting type after dereferencing.
Source§

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

Dereferences the value.
Source§

impl Hash for AVCaptureOutput

Source§

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

Feeds this value into the given Hasher. Read more
1.3.0 · Source§

fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
Source§

impl Message for AVCaptureOutput

Source§

fn retain(&self) -> Retained<Self>
where Self: Sized,

Increment the reference count of the receiver. Read more
Source§

impl NSObjectProtocol for AVCaptureOutput

Source§

fn isEqual(&self, other: Option<&AnyObject>) -> bool
where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object. Read more
Source§

fn hash(&self) -> usize
where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure. Read more
Source§

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. Read more
Source§

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. Read more
Source§

fn isMemberOfClass(&self, cls: &AnyClass) -> bool
where Self: Sized + Message,

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

fn respondsToSelector(&self, aSelector: Sel) -> bool
where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector. Read more
Source§

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool
where Self: Sized + Message,

Check whether the object conforms to a given protocol. Read more
Source§

fn description(&self) -> Retained<NSObject>
where Self: Sized + Message,

A textual representation of the object. Read more
Source§

fn debugDescription(&self) -> Retained<NSObject>
where Self: Sized + Message,

A textual representation of the object to use when debugging. Read more
Source§

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. Read more
Source§

fn retainCount(&self) -> usize
where Self: Sized + Message,

The reference count of the object. Read more
Source§

impl PartialEq for AVCaptureOutput

Source§

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

Tests for self and other values to be equal, and is used by ==.
1.0.0 · Source§

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

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

impl RefEncode for AVCaptureOutput

Source§

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

The Objective-C type-encoding for a reference of this type. Read more
Source§

impl DowncastTarget for AVCaptureOutput

Source§

impl Eq for AVCaptureOutput

Auto Trait Implementations§

Blanket Implementations§

Source§

impl<T> Any for T
where T: 'static + ?Sized,

Source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
Source§

impl<'a, T> AnyThread for T
where T: ClassType<ThreadKind = dyn AnyThread + 'a> + ?Sized,

Source§

fn alloc() -> Allocated<Self>
where Self: Sized + ClassType,

Allocate a new instance of the class. Read more
Source§

impl<T> Borrow<T> for T
where T: ?Sized,

Source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
Source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

Source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
Source§

impl<T> From<T> for T

Source§

fn from(t: T) -> T

Returns the argument unchanged.

Source§

impl<T, U> Into<U> for T
where U: From<T>,

Source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Source§

impl<P, T> Receiver for P
where P: Deref<Target = T> + ?Sized, T: ?Sized,

Source§

type Target = T

🔬This is a nightly-only experimental API. (arbitrary_self_types)
The target type on which the method may be called.
Source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

Source§

type Error = Infallible

The type returned in the event of a conversion error.
Source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
Source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

Source§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
Source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
Source§

impl<T> AutoreleaseSafe for T
where T: ?Sized,