Explore media metadata publishing and playback interactions

Highlight

iOS 16 willMPNowPlayingSessionExtended from tvOS to iPhone and iPad, with the automatic metadata publishing function, developers can make the application’s playback information correctly displayed on the control center, lock screen, Apple Watch and HomePod with just a few lines of code.

Core Content

Now Playing everywhere

When users adjust the volume in the Control Center, they will see the cover and title of the currently playing content. Quickly pause or AirPlay to other devices while locked. There’s also the Now Playing App on Apple Watch, and there’s even an Apple TV remote built-in.

These interfaces all rely on the application to publish metadata correctly. If the metadata is missing or not updated in time, the user experience will be broken - the cover will not be displayed, the progress bar will be inaccurate, and the remote control will not respond.

MPNowPlayingSession unifies multiple platforms

（02:18）

MPNowPlayingSessionPreviously exclusive on tvOS, iOS 16 is officially available. It represents an independent playback session, and an application can have multiple sessions - such as one for the main player and one for picture-in-picture.

The system determines whether an application is eligible to become a Now Playing application based on two conditions:

Automatic release reduces maintenance burden

（07:16）

iOS 16 adds automatic metadata publishing. After opening,MPNowPlayingSessionAutomatically observe player status and update fields such as duration, elapsed play time, and play status in real time. Developers only need to set the title and cover and leave the rest to the system.

Detailed Content

Create a playback session

（04:34）

Single player scenario:

self.session = MPNowPlayingSession(players: [player])

Picture-in-picture scene, two independent sessions:

self.session = MPNowPlayingSession(players: [player])
self.pipSession = MPNowPlayingSession(players: [pipPlayer])

Multiple perspectives and same content scenarios, multiple players in one session:

self.session = MPNowPlayingSession(players: [topLeft, topRight, bottomLeft, bottomRight])

Key points:

the sameMPNowPlayingSessionMultiple players within should belong to the same content
Multi-session scenarios require manual promotion of active sessions

Switch active session

（04:58）

To switch active sessions when picture-in-picture content is full screen:

self.pipSession.becomeActiveIfPossible { becameActive in
    // After success, pipSession data is populated on the Lock Screen and in Control Center
    // Remote control commands are also routed to pipSession
}

Key points:

becomeActiveIfPossibleIt is asynchronous, and the success is confirmed through callback.
The system may refuse to switch (if another app is playing)

Respond to remote commands

（05:32）

Play and pause:

self.session = MPNowPlayingSession(players: [player])

self.session.remoteCommandCenter.playCommand.addTarget { event in
    player.play()
    return .success
}

self.session.remoteCommandCenter.pauseCommand.addTarget { event in
    player.pause()
    return .success
}

Fast forward command:

self.session.remoteCommandCenter.skipForwardCommand.preferredIntervals = [15.0]
self.session.remoteCommandCenter.skipForwardCommand.addTarget { event in
    let skipCommand = event as! MPSkipIntervalCommandEvent
    let newTime = CMTimeAdd(
        player.currentTime(),
        CMTimeMakeWithSeconds(skipCommand.interval, preferredTimescale: 1)
    )
    player.seek(to: newTime)
    return .success
}

// Disable fast-forwarding during ads
self.session.remoteCommandCenter.skipForwardCommand.isEnabled = false

Key points:

eachMPNowPlayingSessionhave ownMPRemoteCommandCenterExample
Register handlers for all applicable commands, unsupported commands can be disabled -preferredIntervalsDefine the number of seconds to fast forward/rewind -MPSkipIntervalCommandEvent.intervalGet the specific skip duration requested by the user
Jump commands should be disabled in scenarios such as live streaming

Automatically publish metadata

（07:48）

Set title and cover, and turn on automatic publishing:

let artwork = MPMediaItemArtwork(image: image)
let title = "Magnificent"

playerItem.nowPlayingInfo = [
    MPMediaItemPropertyTitle: title,
    MPMediaItemPropertyArtwork: artwork
]

self.session = MPNowPlayingSession(players: [player])
self.session.automaticallyPublishNowPlayingInfo = true

Key points:

nowPlayingInfoThe dictionary is set inAVPlayerItemsuperior -MPMediaItemPropertyTitleSet title -MPMediaItemPropertyArtworkSet the cover, the type isMPMediaItemArtwork
automaticallyPublishNowPlayingInfo = trueTurn on automatic publishing
The system automatically observes the player and updates the duration, elapsed play time, and play status

Handling inline ads:

let preroll = MPAdTimeRange(
    timeRange: CMTimeRange(
        start: CMTime.zero,
        duration: CMTimeMakeWithSeconds(30, preferredTimescale: 1)
    )
)

playerItem.nowPlayingInfo = [
    MPMediaItemPropertyTitle: title,
    MPMediaItemPropertyArtwork: artwork,
    MPNowPlayingInfoPropertyAdTimeRanges: [preroll]
]

self.session = MPNowPlayingSession(players: [player])
self.session.automaticallyPublishNowPlayingInfo = true

Key points:

MPAdTimeRangeMark advertising time slots -MPNowPlayingInfoPropertyAdTimeRangesPass in advertising array
Automatic press conferences automatically deduct advertising time and calculate the net playback time

AVKit metadata settings

（11:02）

When using AVKit on tvOS, passexternalMetadataset up:

let path = Bundle.main.path(forResource: "poster", ofType: "jpg")!
let posterData = FileManager.default.contents(atPath: path)!

let artwork = AVMutableMetadataItem()
artwork.identifier = .commonIdentifierArtwork
artwork.value = posterData as NSData
artwork.dataType = kCMMetadataBaseDataType_JPEG as String
artwork.extendedLanguageTag = "und"

let title = AVMutableMetadataItem()
title.identifier = .commonIdentifierTitle
title.value = "Magnificent" as NSString
title.extendedLanguageTag = "und"

playerItem.externalMetadata = [artwork, title]

Key points:

AVMutableMetadataItemUsed to build metadata items -identifierSpecify the metadata type,.commonIdentifierArtworkIndicates cover -valueIt is the actual data, used for the coverNSData, for titleNSString
dataTypeIndicate the image format,kCMMetadataBaseDataType_JPEGor_PNG
extendedLanguageTaguse"und"(undefined) Ensures all locales are visible
AVKit automatically handles remote command and metadata publishing

Manually publish metadata

（12:59）

Not usedMPNowPlayingSessionFallback when:

let artwork = MPMediaItemArtwork(image: image)

let nowPlayingInfo: [String: Any] = [
    MPMediaItemPropertyTitle: title,
    MPMediaItemPropertyArtwork: artwork,
    MPMediaItemPropertyPlaybackDuration: playerItem.duration,
    MPNowPlayingInfoPropertyElapsedPlaybackTime: player.currentTime().seconds,
    MPNowPlayingInfoPropertyPlaybackRate: player.rate
]

MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo

Update elapsed time and playback rate:

var nowPlayingInfo = MPNowPlayingInfoCenter.default().nowPlayingInfo
nowPlayingInfo?[MPNowPlayingInfoPropertyElapsedPlaybackTime] = player.currentTime().seconds
nowPlayingInfo?[MPNowPlayingInfoPropertyPlaybackRate] = player.rate
MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo

Key points:

Manual publishing requires maintaining all fields by yourself
Update metadata when playing/pausing, jumping, switching content
There is no need to update the played time periodically, the system will automatically calculate it based on the last update and playback rate
useMPNowPlayingInfoCenter.default()shared instance of

Core Takeaways

What: Adds full lock screen control support to the podcast app
Why it’s worth doing: Users often listen to podcasts while driving or exercising, and lock screen and headphone control are the main modes of interaction.
How to get started: CreateMPNowPlayingSession, register play/pause/skipForward/skipBackward command, setnowPlayingInfoContains title, cover, and chapter information
What to do: Build a multi-room audio control application
Why it’s worth it: Users can control playback on iPhone via HomePod, and metadata publishing makes this cross-device control work seamlessly
How to start: Make sureAVAudioSessionTo configure the non-mixing class, register the remote command handler, useMPNowPlayingSessionManage playback status
What to do: Develop a video application that supports picture-in-picture
Why it’s worth it: Multi-session management allows Now Playing information to always be correct when users switch between picture-in-picture and full screen
How to start: Create for main player and picture-in-pictureMPNowPlayingSession, called when switchingbecomeActiveIfPossible
What to do: Create a live streaming app
WHY IT’S WORTH IT: Live streaming scenarios require disabling certain commands (like fast forward) while keeping other controls available
How to start: After registering the command, set it dynamically according to the live broadcast statusisEnabled, disable skip functionality during commercials

Create a more responsive media app — Build a responsive media app using AVFoundation
Deliver reliable streams with HLS Content Steering — HLS content steering technology
What’s new in AVKit — AVKit new features

Highlight

Core Content

Now Playing everywhere

MPNowPlayingSession unifies multiple platforms

Automatic release reduces maintenance burden

Detailed Content

Create a playback session

Switch active session

Respond to remote commands

Automatically publish metadata

AVKit metadata settings

Manually publish metadata

Core Takeaways

Related Sessions

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