Class

AVCaptureVideoPreviewLayer

A Core Animation layer that displays the video as it’s captured.

Declaration

class AVCaptureVideoPreviewLayer : CALayer

Overview

AVCaptureVideoPreviewLayer is a subclass of CALayer that you use to display video as it’s captured by an input device.

You use this preview layer in conjunction with a capture session, as shown in the following code fragment.

// Create a preview layer.
let previewLayer = AVCaptureVideoPreviewLayer()

// Connect the preview layer with the capturing session.
previewLayer.session = captureSession

// Add the preview layer into the view's layer hierarchy.
view.layer.addSublayer(previewLayer)

Topics

Creating a Preview Layer

init(session: AVCaptureSession)

Initializes a preview layer with a given capture session.

init(sessionWithNoConnection: AVCaptureSession)

Initializes a preview layer using a given capture session but without making any connections.

Layer Configuration

var videoGravity: AVLayerVideoGravity

Indicates how the layer displays the video content within its bounds.

var isPreviewing: Bool

A Boolean value that indicates whether the layer is rendering video frames from its source.

Beta

Session Configuration

var session: AVCaptureSession?

The previewed capture session.

var connection: AVCaptureConnection?

The capture connection describing the AVCaptureInputPort to which the preview layer is connected.

func setSessionWithNoConnection(AVCaptureSession)

Attaches the layer to a given session without implicitly forming a connection.

Converting Between Coordinate Systems

func captureDevicePointConverted(fromLayerPoint: CGPoint) -> CGPoint

Converts a point from layer coordinates to the coordinate space of the capture device.

func layerPointConverted(fromCaptureDevicePoint: CGPoint) -> CGPoint

Converts a point from the coordinate space of the capture device to the coordinate space of the layer.

func layerRectConverted(fromMetadataOutputRect: CGRect) -> CGRect

Converts a rectangle in the coordinate system used for metadata outputs to one in the preview layer’s coordinate system.

func metadataOutputRectConverted(fromLayerRect: CGRect) -> CGRect

Converts a rectangle in the preview layer’s coordinate system to one in the coordinate system used for metadata outputs.

func transformedMetadataObject(for: AVMetadataObject) -> AVMetadataObject?

Converts a metadata object’s visual properties to layer coordinates.

Relationships

Inherits From

Conforms To

See Also

Media Capture Preview

class AVCaptureAudioPreviewOutput

A capture output that provides preview playback for audio being recorded in a capture session.

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

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