Hi, In my project I am using AVFoundation for recording the audio. We are using AVAudioMixerNode class below method to record the audio packet.
**func installTap(
onBus bus: AVAudioNodeBus,
bufferSize: AVAudioFrameCount,
format: AVAudioFormat?,
block tapBlock: @escaping AVAudioNodeTapBlock
)
**
It works perfectly fine.
But in production env some small percentage of the user we are facing issue like after recording few packets it stops automatically without stopping the audio engine. Can anyone help here that why this happens? I have also observed for mediaServicesWereResetNotification and added log on receiving this notification but when this issue happens I don't see any occurence of this log. Also is there any callback when the engine stops?
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Hello! I am trying to determine the best approach with AVPlayer for implementing auto-play, that is, playback that automatically starts without user initiation. Ideally this would work for both local and streaming audio.
My current approach is using KVO and the status on an AVPlayerItem equal to readyToPlay to do this, but I was wondering if there was a better property or state to use, or, alternatively, whether this use case may already be handled when automaticallyWaitsToMinimizeStalling is true, so that I could simply write:
player.replaceCurrentItem(with: AVPlayerItem(url: streamingUrl))
player.rate = 1
or
let playerItem = AVPlayerItem(url: streamingUrl)
player = AVPlayer(playerItem: playerItem)
player.rate = 1
and expect the item to be auto-played when ready.
In the context of user-initiated playback, I've typically seen code that makes a button's enabled state contingent on player.currentItem.duration, e.g. in AVFoundationSimplePlayer-iOS. On the other hand, AVAutoWait, which utilizes automaticallyWaitsToMinimizeStalling, does not seem to do this.
As a side note, I am not using an AVQueuePlayer.
Topic:
Media Technologies
SubTopic:
Streaming
I'm seeking to a specific sync frame in a video file (HEVC, recorded on iPad). When I feed the buffers from that sync frame on to VTDecompressionSession it consistently drops the 2.,3.,4. buffer with a kVTVideoDecoderReferenceMissingErr (or no error but no buffer on the simulator). If I feed all the buffers from the penultimate sync frame prior to the desired frame the buffers come out fine but that would just create a massive overhead to always do it. Tried multiple OS versions, devices etc. Seems a consistent problem.
Here's a sample project with the offending video (disregard memory handling etc):
https://github.com/marcuseckert/vtSample
I've filed a radar FB18228296 but would appreciate any feedback on circumventing or at least detecting this behavior prior to decoding.
In Final Cut Pro, keyframes for transform parameters (such as Position, Scale, and Rotation) are automatically set to “Smooth” interpolation. This often results in undesired easing between keyframes, especially when linear motion is required.
Currently, we have to manually adjust each keyframe to "Linear" using the Video Animation Editor, which can be time-consuming when working with many keyframes.
Would it be possible to add an option to set the default keyframe interpolation to "Linear"—either globally in Preferences or per parameter in the Inspector?
This would greatly streamline the animation workflow for many editors.
Thank you for considering this request!
Hello Apple Developer Community,
We are developing a music management platform for restaurants and cafes in Saudi Arabia. Our app enables businesses to schedule playlists and allows visitors to request songs via barcodes. Music playback is powered by Apple Music, and users must have their own Apple Music subscriptions to access the music. Our service charges a monthly subscription fee for these management features, not for music access itself.
Project Overview and MusicKit Role
Our app integrates MusicKit to leverage Apple Music’s catalog and playback capabilities. Users log in with their Apple Music accounts, ensuring they have an active subscription for music playback. Our platform’s value lies in its tools—playlist scheduling and song requests—which are built on top of MusicKit’s APIs. We offer these features exclusively in Saudi Arabia.
Legal Context in Saudi Arabia
In Saudi Arabia, to our understanding, no special licenses are required for playing music in commercial venues like restaurants and cafes. This means our clients can use Apple Music subscriptions for playback without additional performance rights licenses. While this aligns with local laws, we recognize that Apple’s global policies may impose stricter requirements, prompting our need for clarification.
Subscription Model and Monetization Concerns
We charge a monthly subscription fee for access to our app’s features (e.g., scheduling playlists and managing song requests). This fee is separate from the Apple Music subscription, which users must maintain for playback. However, Apple’s MusicKit terms state: "You agree not to require payment for or indirectly monetize access to the Apple Music service." We’re concerned whether our subscription model might be interpreted as indirectly monetizing Apple Music access, given its reliance on MusicKit for functionality.
Scheduling Feature and Synchronization Rights
Our app allows businesses to schedule playlists for general time slots (e.g., “play this playlist from 6 PM to 8 PM”). It does not support precise scheduling, such as playing a specific song at an exact moment (e.g., “play this song at 7:30 PM”). Apple’s guidelines mention that “deeper or more complex music integration” may require additional licenses, like synchronization rights. We’re unsure if our general scheduling feature crosses this threshold or remains within MusicKit’s standard usage.
Questions for Clarification
We’d greatly appreciate expert input on the following:
Monetization: Does our subscription fee for management features (scheduling and song requests) violate Apple’s policy against indirectly monetizing Apple Music access?
Local Context: Given that Saudi Arabia requires no additional licenses for commercial music playback, does this impact our compliance with Apple’s global terms?
Scheduling: Does our playlist scheduling for general time slots (not exact moments) fall within MusicKit’s permitted scope, or does it require further licensing?
Thank you in advance for any insights or guidance to ensure our app aligns with Apple’s policies!
Topic:
Media Technologies
SubTopic:
General
Tags:
Apple Music API
MusicKit
MusicKit JS
Apple Music Feed
I’m building a music app using Apple Music streaming via ApplicationMusicPlayer.
My goal is to decrease the volume of the current song during the last 10 seconds, and when the next track begins, restore the volume to its normal level.
I know that ApplicationMusicPlayer doesn’t expose a volume API, and I want to avoid triggering the system volume HUD.
✅ Using Apple Music streaming (not local files)
❓ Is it possible to implement per-track fade-out/fade-in logic with ApplicationMusicPlayer?
Appreciate any clarification or official guidance!
Hello!
I'm experiencing an issue with iOS's audio routing system when trying to use Bluetooth headphones for audio output while also recording environmental audio from the built-in microphone.
Desired behavior:
Play audio through Bluetooth headset (AirPods)
Record unprocessed environmental audio from the iPhone's built-in microphone
Actual behavior:
When explicitly selecting the built-in microphone, iOS reports it's using it (in currentRoute.inputs)
However, the actual audio data received is clearly still coming from the AirPods microphone
The audio is heavily processed with voice isolation/noise cancellation, removing environmental sounds
Environment Details
Device: iPhone 12 Pro Max
iOS Version: 18.4.1
Hardware: AirPods
Audio Framework: AVAudioEngine (also tried AudioQueue)
Code Attempted
I've tried multiple approaches to force the correct routing:
func configureAudioSession() {
let session = AVAudioSession.sharedInstance()
// Configure to allow Bluetooth output but use built-in mic
try? session.setCategory(.playAndRecord,
options: [.allowBluetoothA2DP, .defaultToSpeaker])
try? session.setActive(true)
// Explicitly select built-in microphone
if let inputs = session.availableInputs,
let builtInMic = inputs.first(where: { $0.portType == .builtInMic }) {
try? session.setPreferredInput(builtInMic)
print("Selected input: \(builtInMic.portName)")
}
// Log the current route
let route = session.currentRoute
print("Current input: \(route.inputs.first?.portName ?? "None")")
// Configure audio engine with native format
let inputNode = audioEngine.inputNode
let nativeFormat = inputNode.inputFormat(forBus: 0)
inputNode.installTap(onBus: 0, bufferSize: 1024, format: nativeFormat) { buffer, time in
// Process audio buffer
// Despite showing "Built-in Microphone" in route, audio appears to be
// coming from AirPods with voice isolation applied - welp!
}
try? audioEngine.start()
}
I've also tried various combinations of:
Different audio session modes (.default, .measurement, .voiceChat)
Different option combinations (with/without .allowBluetooth, .allowBluetoothA2DP)
Setting session.setPreferredInput() both before and after activation
Diagnostic Observations
When AirPods are connected:
AVAudioSession.currentRoute.inputs correctly shows "Built-in Microphone" after setPreferredInput()
The actual audio data received shows clear signs of AirPods' voice isolation processing
Background/environmental sounds are actively filtered out...
When recording a test audio played near the phone (not through the app), the recording is nearly silent. Only headset voice goes through.
Questions
Is there a workaround to force iOS to actually use the built-in microphone while maintaining Bluetooth output?
Are there any lower-level configurations that might resolve this issue?
Any insights, workarounds, or suggestions would be greatly appreciated. This is blocking a critical feature in my application that requires environmental audio recording while providing audio feedback through headphones 😅
I’m developing a macOS audio monitoring app using AVAudioEngine, and I’ve run into a critical issue on macOS 26 beta where AVFoundation fails to detect any input devices, and AVAudioEngine.start() throws the familiar error 10877.
FB#: FB19024508
Strange Behavior:
AVAudioEngine.inputNode shows no channels or input format on bus 0.
AVAudioEngine.start() fails with -10877 (AudioUnit connection error).
AVCaptureDevice.DiscoverySession returns zero audio devices.
Microphone permission is granted (authorized), and the app is properly signed and sandboxed with com.apple.security.device.audio-input.
However, CoreAudio HAL does detect all input/output devices:
Using AudioObjectGetPropertyDataSize and AudioObjectGetPropertyData with kAudioHardwarePropertyDevices, I can enumerate 14+ devices, including AirPods, USB DACs, and BlackHole.
This suggests the lower-level audio stack is functional.
I have tried:
Resetting CoreAudio with sudo killall coreaudiod
Rebuilding and re-signing the app
Clearing TCC with tccutil reset Microphone
Running on Apple Silicon and testing Rosetta/native detection via sysctl.proc_translated
Using a fallback mechanism that logs device info from HAL and rotates logs for submission via Feedback Assistant
I have submitted logs and a reproducible test case via Feedback Assitant : FB#: FB19024508]
I'm currently using ReplayKit for background screen recording, but I can't determine whether the screen is in landscape mode from the CMSampleBuffer. All other APIs for detecting screen orientation are foreground-based. What should I do?
When I create a SFSpeechRecognizer object, I find SFLocalSpeechRecognitionClient remains in memory and never gets released.
You can create a demo with a single UIButton whose touch action is
SFSpeechRecognizer(locale: Locale(identifier: "zh_CN"))
I want to create a Live Photo. The project includes a .jpg image and a .mov video (2 seconds).
Two permissions in xcode have been added:
Privacy - Photo Library Usage Description
Privacy - Photo Library Additions Usage Description
Simulate: iphone 16, ios 18.3
The codes in ContentView.swift :
private func saveLivePhoto(imageURL: URL, videoURL: URL, completion: @escaping (Bool, Error?) -> Void) {
PHPhotoLibrary.shared().performChanges {
let creationRequest = PHAssetCreationRequest.forAsset()
let options = PHAssetResourceCreationOptions()
options.shouldMoveFile = false
creationRequest.addResource(with: .photo, fileURL: imageURL, options: options)
creationRequest.addResource(with: .pairedVideo, fileURL: videoURL, options: options)
} completionHandler: { success, error in
DispatchQueue.main.async {
print(error)
completion(success, error)
}
}
}
guard let imageURL = Bundle.main.url(forResource: "livephoto", withExtension: "jpeg"),
let videoURL = Bundle.main.url(forResource: "livephoto", withExtension: "mov") else {
showAlertMessage(title: "error", message: "cant find Live Photo ")
return
}
print("imageURL: \(imageURL)")
print("videoURL: \(videoURL)")
saveLivePhoto(imageURL: imageURL, videoURL: videoURL) { success, error in
if success {
xxxxx
} else {
xxxxx
}
}
Really need help, thanks
I am following the Apple sample code and trying to add a manual focus lens position slider:
@available(iOS 18.0, *)
private func addCameraControls() {
if !self.session.controls.isEmpty {
for control in self.session.controls {
self.session.removeControl(control)
}
}
self.cameraControlFocusSlider = nil
//Focus Slider
if self.videoDevice!.isLockingFocusWithCustomLensPositionSupported {
self.cameraControlFocusSlider = AVCaptureSlider("Focus", symbolName: "dot.square", in: 0.0...1.0)
self.cameraControlFocusSlider!.setActionQueue(self.sessionQueue) { focusValue in
//Do manual focus
}
if self.session.canAddControl(self.cameraControlFocusSlider!) {
self.session.addControl(self.cameraControlFocusSlider!)
}
}
}
So there are these AVCaptureSessionControlsDelegate methods:
final func sessionControlsDidBecomeActive(_ session: AVCaptureSession) {
print ("sessionControlsDidBecomeActive")
}
final func sessionControlsWillEnterFullscreenAppearance(_ session: AVCaptureSession) {
print ("sessionControlsWillEnterFullscreenAppearance")
}
final func sessionControlsWillExitFullscreenAppearance(_ session: AVCaptureSession) {
print ("sessionControlsWillExitFullscreenAppearance")
}
final func sessionControlsDidBecomeInactive(_ session: AVCaptureSession) {
print ("sessionControlsDidBecomeInactive")
}
So when self.cameraControlFocusSlider is presented, I have to show the current value of the lense position. Lens position can change from auto focus and also from manual focus by the user using the app UI. Is there a way to see if self.cameraControlFocusSlider is active or being used?
Please note that I will have more than one AVCaptureSlider in the final code.
Hi, I'm trying to plan out development of an app and am wondering if it is possible to have user generated content automatically populate into a custom shazamkit catalogue and be able to query this catalogue non-locally?
Storing all the submissions locally would obviously not scale.
I have an app that has a WKWebView for watching YouTube videos. When the videos are windowed the audio seems fine, positionally as well. All perfectly.
When I fullscreen the video and it goes into the native visionOS video player the audio messes up.
It will suddenly sound like it is in your ears, or maybe even just one ear channel, or the position will be wrong. It might be fine for a moment but the second I touch the controls or move the window the sound jumps across the room, away from the window, or switches to stereo.
Sometimes exiting windows entirely you will still hear the videos playing. Even if you open the window back up and go to another screen and open another video, now you hear 2 videos playing at the same time with no way to stop the first one in the background, requiring to force restart the app.
It is all sorts of glitchy. I haven't the slightest clue what is happening here. I am strongly feeling this is a visionOS bug.
I tried using AVAudioSession to change some of the sound settings, and that makes zero difference in behavior.
Multiple testers have also reported this behavior and it has been seen on both visionOS 2.3 and 2.4 betas.
Thanks for the help! This is driving me mad! It is extremely consistent behavior!
I'm having a crash on an app that plays videos when the users activates close captions.
I was able to replicate the issue on an empty project. The crash happens when the AVPlayerLayer is used to instantiate an AVPictureInPictureController
These are the example project where I tested the crash:
struct ContentView: View {
var body: some View {
VStack {
VideoPlaylistView()
}
.frame(maxWidth: .infinity, maxHeight: .infinity)
.background(Color.black.ignoresSafeArea())
}
}
class VideoPlaylistViewModel: ObservableObject {
// Test with other videos
var player: AVPlayer? = AVPlayer(url: URL(string:"https://d2ufudlfb4rsg4.cloudfront.net/newsnation/WIpkLz23h/adaptive/WIpkLz23h_master.m3u8")!)
}
struct VideoPlaylistView: View {
@StateObject var viewModel = VideoPlaylistViewModel()
var body: some View {
ScrollView {
VideoCellView(player: viewModel.player)
.onAppear {
viewModel.player?.play()
}
}
.scrollTargetBehavior(.paging)
.ignoresSafeArea()
}
}
struct VideoCellView: View {
let player: AVPlayer?
@State var isCCEnabled: Bool = false
var body: some View {
ZStack {
PlayerView(player: player)
.accessibilityIdentifier("Player View")
}
.containerRelativeFrame([.horizontal, .vertical])
.overlay(alignment: .bottom) {
Button {
player?.currentItem?.asset.loadMediaSelectionGroup(for: .legible) { group,error in
if let group {
let option = !isCCEnabled ? group.options.first : nil
player?.currentItem?.select(option, in: group)
isCCEnabled.toggle()
}
}
} label: {
Text("Close Captions")
.font(.subheadline)
.foregroundStyle(isCCEnabled ? .red : .primary)
.buttonStyle(.bordered)
.padding(8)
.background(Color.blue.opacity(0.75))
}
.padding(.bottom, 48)
.accessibilityIdentifier("Button Close Captions")
}
}
}
import Foundation
import UIKit
import SwiftUI
import AVFoundation
import AVKit
struct PlayerView: UIViewRepresentable {
let player: AVPlayer?
func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<PlayerView>) {
}
func makeUIView(context: Context) -> UIView {
let view = PlayerUIView()
view.playerLayer.player = player
view.layer.addSublayer(view.playerLayer)
view.layer.backgroundColor = UIColor.red.cgColor
view.pipController = AVPictureInPictureController(playerLayer: view.playerLayer)
view.pipController?.requiresLinearPlayback = true
view.pipController?.canStartPictureInPictureAutomaticallyFromInline = true
view.pipController?.delegate = view
return view
}
}
class PlayerUIView: UIView, AVPictureInPictureControllerDelegate {
let playerLayer = AVPlayerLayer()
var pipController: AVPictureInPictureController?
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
playerLayer.frame = bounds
playerLayer.backgroundColor = UIColor.green.cgColor
}
func pictureInPictureController(_ pictureInPictureController: AVPictureInPictureController, failedToStartPictureInPictureWithError error: any Error) {
print("Error starting Picture in Picture: \(error.localizedDescription)")
}
}
class AppDelegate: NSObject, UIApplicationDelegate {
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
let audioSession = AVAudioSession.sharedInstance()
do {
try audioSession.setCategory(.playback, mode: .moviePlayback)
try audioSession.setActive(true)
} catch {
print("ERR: \(error.localizedDescription)")
}
return true
}
}
UITest to make the app crash:
final class VideoPlaylistSampleUITests: XCTestCase {
func testCrashiOS26ToggleCloseCaptions() throws {
let app = XCUIApplication()
app.launch()
let videoPlayer = app.otherElements["Player View"]
XCTAssertTrue(videoPlayer.waitForExistence(timeout: 30))
let closeCaptionButton = app.buttons["Button Close Captions"]
for _ in 0..<2000 {
closeCaptionButton.tap()
}
}
}
Hello,
i can successfully match music using shazamkit on Apple using SwiftUI, a simple app that let user to load an audio file and exctracts the relative match, while i am unable to match music using shamzamkit on Android. I am trying to make the same simple app but i cannot match music as i get MATCH_ATTEMPT_FAILED every time i try to. I don't know what i am doing wrong but the shazam part in the kotlin Android code is in this method :
suspend fun processAudioFileInBackground(
filePath: String,
developerTokenProvider: DeveloperTokenProvider
) = withContext(Dispatchers.IO) {
val bufferSize = 1024 * 1024
val audioFile = FileInputStream(filePath)
val byteBuffer = ByteBuffer.allocate(bufferSize)
byteBuffer.order(ByteOrder.LITTLE_ENDIAN)
var bytesRead: Int
while (audioFile.read(byteBuffer.array()).also { bytesRead = it } != -1) {
val signatureGenerator = (ShazamKit.createSignatureGenerator(AudioSampleRateInHz.SAMPLE_RATE_44100) as ShazamKitResult.Success).data
signatureGenerator.append(byteBuffer.array(), bytesRead, System.currentTimeMillis())
val signature = signatureGenerator.generateSignature()
println("Signature: ${signature.durationInMs}")
val catalog = ShazamKit.createShazamCatalog(developerTokenProvider, Locale.ENGLISH)
val session = (ShazamKit.createSession(catalog) as ShazamKitResult.Success).data
val matchResult = session.match(signature)
println("MatchResult : $matchResult")
setMatchResult(matchResult)
byteBuffer.clear()
}
audioFile.close()
}
I noticed that changing Locale in catalog creation results in different result as i get NoMatch without exception. Can you please help me with this? Do i need to create a custom catalog?
Howdy. I'm trying to access media from a users song library and receive:
<ICUserIdentityStoreACAccountBackend: 0x148f8af30> Failed to initialize active account, error=Error Domain=ICError Code=-7013 "Client is not entitled to access account store" UserInfo={NSDebugDescription=Client is not entitled to access account store}
I'm told I need to add a Media Library Access Capability. Nothing like this shows up in Xcode under Signing & Capabilities > +Capabilities. Also I can't find anything like this in my account in dev.apple.com.
How do I enable myself and a test user using another iPhone device to access my music and their music respectively?
Thanks!
Topic:
Media Technologies
SubTopic:
General
Tags:
App Tracking Transparency
Media Player
iOS
MusicKit
I'm developing a video capture app using AVFoundation, designed specifically for use on a boat pylon to record slalom water skiing. This setup involves considerable vibration.
As you may know, the OIS that Apple began adding to lenses since the iPhone 7 is actually very problematic in high vibration circumstances, ironically creating very shaky video, whereas lenses without OIS produce perfectly stable video. Because of this, up until iPhone 14, the solution for my app was simply to use the Selfie lens, which did not have OIS.
Starting with iPhone 14 through iPhone 16 (non-Pro models), technical specs suggest the selfie lens still does not include OIS. However, I’m still seeing the same kind of shaky video behavior I see on OIS-equipped lenses. The one hardware change I see in this camera module is the addition of PDAF (Phase Detection Autofocus), so that is my best guess as to what is causing the unstable video.
1- Does that make any sense - that in high vibration settings, PDAF could create unstable video in the same way that OIS does? Or could it be something else that was changed between the iPhone 13 and 14 Selfie lens?
Thinking that the issue was PDAF, I figured that if I enabled my app to set a Manual Focus level, that ought to circumvent PDAF (expecting that if a lens is manually focusing, it can’t also be autofocusing via PDAF).
However, even with manual focus locked via AVCaptureDevice in my app, on the Selfie lens of an iPhone 16, the video still comes out very shaky, basically unusable. I also tested with the built-in Apple Camera app (using the press-and-hold to lock focus and exposure) and another 3rd party camera app to lock focus, all with the same results, so it's not that my app just isn't correctly doing manual focus.
So I'm stuck with these questions:
2- Does the selfie camera on iPhones 14–16 use PDAF even when focus is set to locked/manual mode?
3- Is there any way in AVFoundation to disable or suppress PDAF during video recording (e.g., a flag, device format setting, or private API)?
4- Is PDAF behavior or suppression documented or controllable via AVCaptureDevice or any related class?
5- If no control of PDAF is available, are there any best practices for stabilizing or smoothing this effect programmatically?
Note that I also have set my app to use the most aggressive form of stabilization available, so it defaults to .cinematicExtendedEnhanced, if that’s not available, then .cinematicExtended, etc. On the 16 Selfie lens, it is using .cinematicExtended. As an additional question:
6- Would those be the most appropriate stabilization settings for a high vibration environment, and if not, what would be best?
I'm using Picture-in-Picture (PiP) mode in my native iOS application, which is similar to Google Meet, using the VideoSDK.live Native iOS SDK. The SDK has built-in support for PiP and it's working fine for the most part.
However, I'm running into a problem:
When the app enters PiP mode, the local camera (self-video) of the participant freezes or stops. I want to fix this and achieve the same smooth behavior seen in apps like Google Meet and WhatsApp, where the local camera keeps working even in PiP mode.
I've been trying to find documentation or examples on how to achieve this but haven't had much luck. I came across a few mentions that using the camera in the background may require special entitlements from Apple (like in the entitlements file). Most of the official documentation says background camera access is restricted due to Apple’s privacy policies.
So my questions are:
Has anyone here successfully implemented background camera access in PiP mode on iOS?
If yes, what permissions or entitlements are required?
How do apps like WhatsApp and Google Meet achieve this functionality on iPhones?
Any help, advice, or pointers would be really appreciated!
Topic:
Media Technologies
SubTopic:
Photos & Camera
According to the documentation (https://developer.apple.com/documentation/avfoundation/avplayeritem/externalmetadata), AVPlayerItem should have an externalMetadata property. However it does not appear to be visible to my app. When I try, I get:
Value of type 'AVPlayerItem' has no member 'externalMetadata'
Documentation states iOS 12.2+; I am building with a minimum deployment target of iOS 18.
Code snippet:
import Foundation
import AVFoundation
/// ... in function ...
// create metadata as described in https://developer.apple.com/videos/play/wwdc2022/110338
var title = AVMutableMetadataItem()
title.identifier = .commonIdentifierAlbumName
title.value = "My Title" as NSString?
title.extendedLanguageTag = "und"
var playerItem = await AVPlayerItem(asset: composition)
playerItem.externalMetadata = [ title ]