Declare your app plays Audible Content while in the Background

You must configure your app’s capabilities to enable it to play audible content while in the background. With this capability enabled, your app’s audio can continue when users switch to another app or when they lock their iOS devices. This capability is also required for enabling advanced playback features like AirPlay streaming and Picture in Picture playback in iOS.

The learn how to configure your app’s capabilities to enable it to play background audio, see Enabling Background Audio.

Setting the Audio Session Category

You must assign an appropriate category to your audio session to ensure your audio plays even with the screen locked and with the Ring/Silent switch set to silent. You cannot rely on the default audio session, whose category is AVAudioSessionCategorySoloAmbient.

For playback to continue when the screen locks, or when the Ring/Silent switch is set to silent, use the AVAudioSessionCategoryPlayback category. See Configuring an Audio Session.

Make sure you app has an active Audio Session before entering the Background

Your app must have an active audio session before entering the background. If your app's audio session is deactivated when the app enters the background your app will be suspended, because as far as the system knows, your app is no longer playing audio.

To learn how to activate an audio session, see Activating an Audio Session.

Special Considerations for Video Media

If the AVPlayer's current item is displaying video on the device's display, playback of the AVPlayer is automatically paused when the app is sent to the background. There are two ways to prevent this pause:

• Disable the video tracks in the player item (file-based content only). See Listing 1.

• Remove the AVPlayerLayer from its associated AVPlayer (set the AVPlayerLayer player property to nil). See Listing 2.

Listing 1  Disabling the video tracks in the player item.

import AVFoundation

let playerItem = <#Your player item#>

let tracks = playerItem.tracks

for playerItemTrack in tracks {

    // Find the video tracks.

    if playerItemTrack.assetTrack.hasMediaCharacteristic(AVMediaCharacteristicVisual) {

        // Disable the track.

        playerItemTrack.isEnabled = false

    }

}

Listing 2  Remove/Restore the AVPlayerLayer and its associated AVPlayer.

import UIKit

import AVFoundation

...

// A `UIView` subclass that is backed by an `AVPlayerLayer` layer.

class PlayerView: UIView {

    var player: AVPlayer? {

        get {

            return playerLayer.player

        }

        set {

            playerLayer.player = newValue

        }

    }

    var playerLayer: AVPlayerLayer {

        return layer as! AVPlayerLayer

    }

    override class var layerClass: AnyClass {

        return AVPlayerLayer.self

    }

}

...

@UIApplicationMain

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    @IBOutlet weak var playerView: PlayerView!

    /*

     Remove the AVPlayerLayer from its associated AVPlayer

     once the app is in the background.

     */

    func applicationDidEnterBackground(_ application: UIApplication) {

        // Remove the player.

        playerView.player = nil

    }

    // Restore the AVPlayer when the app is active again.

    func applicationDidBecomeActive(_ application: UIApplication) {

        // Restore the player.

        playerView.player = <#Your player#>

    }

}