Struct AVCapturePrimaryConstituentDeviceSwitchingBehavior 

#[repr(transparent)]
pub struct AVCapturePrimaryConstituentDeviceSwitchingBehavior(pub NSInteger);

Available on crate feature AVCaptureDevice only.

These constants can be used to control when the virtual device is allowed to switch the active primary constituent device.

Indicates that the device does not support constituent device switching. This is reported for cameras that do not have more than one constituent device.

Automatically select the best camera for the current scene. In this mode there are no restrictions on when a camera switch can occur.

Restrict fallback camera selection to certain conditions (see AVCapturePrimaryConstituentDeviceRestrictedSwitchingBehaviorConditions). Camera switches necessary to satisfy the requested video zoom factor are still allowed without restriction.

Lock camera switching to the active primary constituent device. Note that this restricts the minAvailableVideoZoomFactor to the switch-over zoom factor of the activePrimaryConstituentDevice (as reported in AVCaptureDevice.virtualDeviceSwitchOverVideoZoomFactors).

Virtual devices with multiple constituent video devices (such as the Dual Camera, Dual Wide Camera, or Triple Camera), consist of cameras that each have different properties such as focal length, maximum light sensitivity, and minimum focus distance. One of the constituent video devices is selected as the primary constituent device. For an AVCaptureSession, the primary constituent device produces for all outputs. For an AVCaptureMultiCamSession, the primary constituent device produces for all outputs connected to the virtual device’s native AVCaptureDeviceInputPort (where its sourceDeviceType is equal to the virtual device’s deviceType).

When the requested zoom factor can be achieved by multiple constituent cameras (see -virtualDeviceSwitchOverVideoZoomFactors), the virtual device chooses the best camera for the scene. The primary condition for this is the focal length; the camera with the longest focal length requires the least amount of digital upscaling and therefore normally provides the highest image quality. Secondary conditions are focus and exposure; when the scene requires focus or exposure to go beyond the limits of the active primary constituent device, a camera with a shorter focal length may be able to deliver a better quality image. Such a device is called a fallback primary constituent device. For example, a telephoto camera with a minimum focus distance of 40cm is not able to deliver a sharp image when the subject in the scene is closer than 40cm. For such a scene, the virtual device will switch to the wide-angle camera which typically has a smaller minimum focus distance and is able to achieve accurate focus on the subject. In this case the wide-angle camera is the fallback primary constitute device.

See also Apple’s documentation

Tuple Fields

0: NSInteger

Implementations

impl AVCapturePrimaryConstituentDeviceSwitchingBehavior

pub const Unsupported: Self

pub const Auto: Self

pub const Restricted: Self

pub const Locked: Self

Trait Implementations

impl Clone for AVCapturePrimaryConstituentDeviceSwitchingBehavior

fn clone(&self) -> AVCapturePrimaryConstituentDeviceSwitchingBehavior

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AVCapturePrimaryConstituentDeviceSwitchingBehavior

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

Formats the value using the given formatter.

impl Encode for AVCapturePrimaryConstituentDeviceSwitchingBehavior

const ENCODING: Encoding = NSInteger::ENCODING

The Objective-C type-encoding for this type.

impl Hash for AVCapturePrimaryConstituentDeviceSwitchingBehavior

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 Ord for AVCapturePrimaryConstituentDeviceSwitchingBehavior

fn cmp( &self, other: &AVCapturePrimaryConstituentDeviceSwitchingBehavior, ) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for AVCapturePrimaryConstituentDeviceSwitchingBehavior

fn eq(&self, other: &AVCapturePrimaryConstituentDeviceSwitchingBehavior) -> 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 PartialOrd for AVCapturePrimaryConstituentDeviceSwitchingBehavior

fn partial_cmp( &self, other: &AVCapturePrimaryConstituentDeviceSwitchingBehavior, ) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl RefEncode for AVCapturePrimaryConstituentDeviceSwitchingBehavior

const ENCODING_REF: Encoding

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

impl Copy for AVCapturePrimaryConstituentDeviceSwitchingBehavior

impl Eq for AVCapturePrimaryConstituentDeviceSwitchingBehavior

impl StructuralPartialEq for AVCapturePrimaryConstituentDeviceSwitchingBehavior