Adopting Picture in Picture for video calls

Add multitasking capability to your video-call apps by using Picture in Picture (PiP).

Overview

Use PiP in your video-call apps so users can multitask with other apps while on video calls. When a user enables PiP, your app scales down to a corner of the screen, so they can see the Home Screen and interact with other apps. In iOS 15 and later, AVKit provides PiP support for video-calling apps, which enables you to deliver a familiar video-calling experience that behaves like FaceTime.

Create a source view

Providing PiP support begins by choosing a source view to display inside the video-call view controller. You need to add a UIView to AVPictureInPictureVideoCallViewController, so use AVCaptureVideoPreviewLayer or AVSampleBufferDisplayLayer depending on your need. In iOS 18 and later, you may also use MTKView as your source view. Video-calling apps need to display the remote view, so use AVSampleBufferDisplayLayer to do so.

class SampleBufferVideoCallView: UIView {
    override class var layerClass: AnyClass {
        AVSampleBufferDisplayLayer.self
    }
    
    var sampleBufferDisplayLayer: AVSampleBufferDisplayLayer {
        layer as! AVSampleBufferDisplayLayer
    }
}

Create a video-call controller

To display your source view, create a AVPictureInPictureVideoCallViewController and add your source as a subview.

let pipVideoCallViewController = AVPictureInPictureVideoCallViewController()
pipVideoCallViewController.preferredContentSize = CGSize(width: 1080, height: 1920)
pipVideoCallViewController.view.addSubview(sampleBufferVideoCallView)

Use isPictureInPictureSupported() to determine whether the current device supports PiP playback. If PiP isn’t supported on the current device, attempting to initialize a PiP controller returns nil.

Create a PiP controller using a content source

Before you create an AVPictureInPictureController, you need to create an AVPictureInPictureController.ContentSource that represents the source of the content the system displays. A content source requires a video-call view controller, and a source view that contains the content you associate with the video call.

let pipContentSource = AVPictureInPictureController.ContentSource(
                            activeVideoCallSourceView: videoCallViewSourceView, 
                            contentViewController: pipVideoCallViewController)

After creating a content source, use it to initialize AVPictureInPictureController. By default, PiP starts when a user moves to the background if your source view is full-screen, or you set canStartPictureInPictureAutomaticallyFromInline to true. If your app is in the foreground, you can start PiP by calling startPictureInPicture().

let pipController = AVPictureInPictureController(contentSource: pipContentSource)
pipController.canStartPictureInPictureAutomaticallyFromInline = true
pipController.delegate = self

The system uses the source view to determine the source frame for the PiP animation, and the restore target for either when the user returns to the app or PiP stops.

Observe PiP life cycle events

When you use PiP, you respond to life-cycle events by observing AVPictureInPictureControllerDelegate. This allows you to handle your app’s user interface based on the PiP state, along with observing for potential errors.

The system interrupts your capture session when the system or user stashes PiP, so observe wasInterruptedNotification for AVCaptureSession.InterruptionReason.videoDeviceNotAvailableInBackground to handle the interruption.

When your app is in PiP mode, it can’t assume control of the camera. For example, Camera.app assumes control of the camera when it’s opened, and the system returns camera control when Camera.app finishes with it. You observe wasInterruptedNotification for AVCaptureSession.InterruptionReason.videoDeviceInUseByAnotherClient to handle the interruption.