On an iOS 18 phone, I use AVCaptureSession to capture HDR with x420 format. The output CMSampleBuffer is HLG colorspace, the propagated attachments contain kCVImageBufferAmbientViewingEnvironmentKey and kCVImageBufferSceneIlluminationKey. Now I use CAMetalLayer to render the CVPixelBuffer to the screen, but the brightness is brighter than AVSampleBufferDisplayLayer. Here is my code. - (void)_updateColorSpaceIfNeed:(CVPixelBufferRef)pixelBuffer { CAMetalLayer *layer = (CAMetalLayer *)_mtkView.layer; if (![layer isKindOfClass:CAMetalLayer.class]) return; layer.wantsExtendedDynamicRangeContent = YES; CFDataRef ambientViewingEnvironment = (CFDataRef)CVBufferCopyAttachment(pixelBuffer, kCVImageBufferAmbientViewingEnvironmentKey, NULL); NSData *data = (__bridge NSData *)ambientViewingEnvironment; if (ambientViewingEnvironment) CFRelease(ambientViewingEnvironment); CAEDRMetadata *metadata = [CAEDRMetadata HLGMetadataWithAmbientViewingEnvironment:data]; // CAEDRMetadata *metadata = [CAEDRMetadata HLGMetadata]; layer.EDRMetadata = metadata; layer.pixelFormat = MTLPixelFormatRGBA16Float; CGColorSpaceRef colorspace = CGColorSpaceCreateWithName(kCGColorSpaceITUR_2100_HLG); layer.colorspace = colorspace; if (colorspace) CGColorSpaceRelease(colorspace); } Why does the CAEDRMetadata class have "HLGMetadataWithAmbientViewingEnvironment:" and "HLGMetadata" methods, but does not provide the "HLGMetadataWithAmbientViewingEnvironment:sceneIllumination" method? I want to know how kCVImageBufferAmbientViewingEnvironmentKey and kCVImageBufferSceneIlluminationKey affect tone mapping. Is there any documentation I can refer to?

Hello, Basically, I am reading and writing an asset. To simplify, I am just reading the asset and rewriting it into an output video without any modifications. However, I want to add a fade-out effect to the last three seconds of the output video. I don’t know how to do this. So far, before adding the CMSampleBuffer to the output video, I tried reducing its volume using an extension on CMSampleBuffer. In the extension, I passed 0.4 for testing, aiming to reduce the video's overall volume by 60%. My question is: How can I directly adjust the volume of a CMSampleBuffer? Here is the extension: extension CMSampleBuffer { func adjustVolume(by factor: Float) -> CMSampleBuffer? { guard let blockBuffer = CMSampleBufferGetDataBuffer(self) else { return nil } var length = 0 var dataPointer: UnsafeMutablePointer<Int8>? guard CMBlockBufferGetDataPointer(blockBuffer, atOffset: 0, lengthAtOffsetOut: nil, totalLengthOut: &length, dataPointerOut: &dataPointer) == kCMBlockBufferNoErr else { return nil } guard let dataPointer = dataPointer else { return nil } let sampleCount = length / MemoryLayout<Int16>.size dataPointer.withMemoryRebound(to: Int16.self, capacity: sampleCount) { pointer in for i in 0..<sampleCount { let sample = Float(pointer[i]) pointer[i] = Int16(sample * factor) } } return self } }

I have created an app where you can speak using SFSpeechRecognizer and it will recognize you speech into text, translate it and then return it back using speech synthesis. All locales for SFSpeechRecognizer and switching between them work fine when the app is in the foreground but after I turn off my screen(the app is still running I just turned off the screen) and try to create new recognitionTask it it receives this error inside the recognition task: User denied access to speech recognition. The weird thing about this is it only happens with some languages. The error happens with Croatian or Hungarian locale for speech recognition but doesn't with English or Spanish locale.

I've been having issues with authorization after switching from v1 to v3, have tried some of the suggestions provided by someone in a reply to a post of mine. Have tried to reach out to Apple Support a few times as well, though I haven't received any support that has helped me to move forward. I have tested my token at https://jwt.io and I'm getting a "Signature Verified", tried multiple browsers in private/incognito mode, now when I try to sign into my Apple Account to test my player I am receiving an error that stats "There is a Problem Connecting. There May be an Issue with Your Network." (which is not the case). I have tried everything I can think of, I'm at a loss and would appreciate any help to get my project moving forward. This is what I am seeing in the browser developer console (using Firefox): Authorization failed: AUTHORIZATION_ERROR: Unauthorized MKError https://js-cdn.music.apple.com/musickit/v3/musickit.js:13 authorize https://js-cdn.music.apple.com/musickit/v3/musickit.js:28 asyncGeneratorStep$w https://js-cdn.music.apple.com/musickit/v3/musickit.js:28 _next https://js-cdn.music.apple.com/musickit/v3/musickit.js:28 media.mydomain.com:398:19 https://media.mydomain.com/:398

I am developing an iOS application that supports screen mirroring to Google TV (or Chromecast with Google TV). My goal is to mirror the iPhone/iPad screen in real time to a Google TV device. What I Have Tried So Far I have explored multiple approaches but haven't found a direct way to achieve low-latency screen mirroring. Here are some of my findings: Google Cast SDK: Google Cast SDK is primarily designed for casting media (videos, images, audio) rather than real-time mirroring. It supports custom receiver applications, but there are no direct APIs for full screen mirroring. Casting a recorded video is possible, but it introduces latency and is not real-time. ReplayKit for Screen Capture: RPScreenRecorder.shared().startCapture(handler: ...) allows capturing the iPhone screen as a video stream. However, sending this stream to Google TV in real time is a challenge. I could potentially encode the video as HLS and stream it, but the delay is significant. RTSP/UDP Streaming: Some third-party libraries support RTSP/UDP streaming for real-time screen sharing. Google TV does not natively support RTSP, making this approach difficult. My Questions: Is it possible to achieve real-time screen mirroring on Google TV using Google Cast SDK? Does Google TV support WebRTC or any low-latency streaming protocol that can be used from iOS? Are there any alternative approaches to mirror an iOS screen to Google TV with minimal latency? I would appreciate any guidance, code examples, or references to relevant documentation.

Hello, I am having difficulties with configuring MusicKit correctly for my web app that I am building, seeking assistance with the issues I am having. Would greatly appreciate any help! After allowing access to the following, "Access Request media.mydomain.com would like to access Apple Music, media library, and listening activity for myemail'@icloud.com.", I get a popup error that states, "Authorization failed. Please try again.". Following is the information that is given in developer console: [Error] Failed to load resource: the server responded with a status of 403 () (webPlayerLogout, line 0) [Error] Authorization failed: AUTHORIZATION_ERROR: Unauthorized (anonymous function) (media.mydomain.com:398)

Hello, I have a command line application that uses iTunesLibrary to "save" the state of what I have listened to. I have it run every night via a LaunchAgent. You can see the source here: https://github.com/bolsinga/itunes_json Prior to Sequoia it would run nightly. I'd just have to grant it access to the Music library once, and it would be fine thereafter. However with Sequoia it requires UI interaction to grant it access every time. This makes it no longer run unattended overnight, defeating its purpose. I have the console logs of when this happens. You can see it in my issue tracking it here: https://github.com/bolsinga/itunes_json/issues/410 One thing that makes me wonder is that it is a command line application, not a bundle. How do I make a command line application get access to MusicKit / iTunesLibrary, and keep it thereafter? I'd like to get my pre-Sequoia behavior back. I've filed FB15592660 too. I've granted it access to run in the background, as well as access to my Music library (please see attached screenshots). AMPLibraryAgent 10:48:29.489944-0700 xpc Connection from framework client invalidated pid:57606 clientname:iTunesLibrary(itunes_json) AMPLibraryAgent 10:48:29.492763-0700 service Unloading domains(14) for ClientID:iTunesLibrary(itunes_json)-1229 previous open:15 new open:1 itunes_json 10:48:59.980864-0700 connection [0x157f05800] activating connection: mach=true listener=false peer=false name=com.apple.amp.library.framework tccd 10:48:59.982568-0700 access AUTHREQ_ATTRIBUTION: msgID=1795.214, attribution={accessing={TCCDProcess: identifier=itunes_json, pid=57652, auid=501, euid=501, binary_path=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json}, requesting={TCCDProcess: identifier=com.apple.AMPLibraryAgent, pid=1795, auid=501, euid=501, binary_path=/System/Library/PrivateFrameworks/AMPLibrary.framework/Versions/A/Support/AMPLibraryAgent}, }, tccd 10:48:59.982651-0700 access requestor: TCCDProcess: identifier=com.apple.AMPLibraryAgent, pid=1795, auid=501, euid=501, binary_path=/System/Library/PrivateFrameworks/AMPLibrary.framework/Versions/A/Support/AMPLibraryAgent is checking access for accessor TCCDProcess: identifier=itunes_json, pid=57652, auid=501, euid=501, binary_path=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json tccd 10:48:59.995636-0700 access AUTHREQ_SUBJECT: msgID=1795.214, subject=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json, tccd 10:48:59.996283-0700 access -[TCCDAccessIdentity staticCode]: static code for: identifier /Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json, type: 1: 0xc00341b00 at /Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json tccd 10:49:00.018205-0700 access Failed to match existing code requirement for subject /Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json and service kTCCServiceMediaLibrary cdhash H"6bc380972f4df49b337a2a05308fb7b98fbe6473" or cdhash H"0708bcaabbfbab8770522050f7e2642d4d864f31" cdhash H"6bc380972f4df49b337a2a05308fb7b98fbe6473" or cdhash H"0708bcaabbfbab8770522050f7e2642d4d864f31" tccd 10:49:00.018997-0700 access AUTHREQ_PROMPTING: msgID=1795.214, service=kTCCServiceMediaLibrary, subject=Sub:{/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json}Resp:{TCCDProcess: identifier=itunes_json, pid=57652, auid=501, euid=501, binary_path=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json}, AMPLibraryAgent 10:49:02.489170-0700 xpc ampld> register framework ClientName:iTunesLibrary(itunes_json) tccd 10:49:02.488189-0700 events Publishing <TCCDEvent: type=Create, service=kTCCServiceMediaLibrary, identifier_type=Path, identifier=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json> to 4 subscribers: { 633 = "<TCCDEventSubscriber: token=633, state=Initial, csid=(null)>"; 628 = "<TCCDEventSubscriber: token=628, state=Passed, csid=com.apple.chronod>"; 464 = "<TCCDEventSubscriber: token=464, state=Passed, csid=com.apple.cloudd>"; 513 = "<TCCDEventSubscriber: token=513, state=Passed, csid=com.apple.photolibraryd>"; } AMPLibraryAgent 10:49:02.490391-0700 xpc ampld> registered framework ClientName:iTunesLibrary(itunes_json) with clientID:1230 itunes_json 10:49:02.792084-0700 connection [0x147e04340] activating connection: mach=true listener=false peer=false name=com.apple.amp.artworkd itunes_json 10:49:02.801482-0700 <Missing Description> openDatabase 0xe4af30f4493e5ef5 artwork folder Y '<private>' itunes_json 10:49:02.805087-0700 <Missing Description> openDatabase 0xf2db6e8d7672edc9 artwork folder Y '<private>' itunes_json 10:49:02.806736-0700 <Missing Description> openDatabase 0xfb2acd898c951851 artwork folder Y '<private>' itunes_json 10:49:02.813286-0700 <Missing Description> openDatabase 0xf0f4919c5ff0e88 artwork folder Y '<private>' itunes_json 10:49:09.634928-0700 connection [0x600002b6a0d0] activating connection: mach=true listener=false peer=false name=com.apple.cfprefsd.daemon itunes_json 10:49:09.635019-0700 connection [0x600002b78000] activating connection: mach=true listener=false peer=false name=com.apple.cfprefsd.agent AMPLibraryAgent 10:49:12.382878-0700 xpc Connection from framework client invalidated pid:57652 clientname:iTunesLibrary(itunes_json) AMPLibraryAgent 10:49:12.383474-0700 service Unloading domains(14) for ClientID:iTunesLibrary(itunes_json)-1230 previous open:15 new open:1 itunes_json.log

I've been using CGWindowListCreateImage which automatically creates an image with the size of the captured window. But SCScreenshotManager.captureImage(contentFilter:configuration:) always creates images with the width and height specified in the provided SCStreamConfiguration. I could be setting the size explicitly by reading SCWindow.frame or SCContentFilter.contentRect and multiplying the width and height by SCContentFilter.pointPixelScale , but it won't work if I want to keep the window shadow with SCStreamConfiguration.ignoreShadowsSingleWindow = false. Is there a way and what's the best way to take full-resolution screenshots of the correct size? import Cocoa import ScreenCaptureKit class ViewController: NSViewController { @IBOutlet weak var imageView: NSImageView! override func viewDidAppear() { imageView.imageScaling = .scaleProportionallyUpOrDown view.wantsLayer = true view.layer!.backgroundColor = .init(red: 1, green: 0, blue: 0, alpha: 1) Task { let windows = try await SCShareableContent.excludingDesktopWindows(false, onScreenWindowsOnly: true).windows let window = windows[0] let filter = SCContentFilter(desktopIndependentWindow: window) let configuration = SCStreamConfiguration() configuration.ignoreShadowsSingleWindow = false configuration.showsCursor = false configuration.width = Int(Float(filter.contentRect.width) * filter.pointPixelScale) configuration.height = Int(Float(filter.contentRect.height) * filter.pointPixelScale) print(filter.contentRect) let windowImage = try await SCScreenshotManager.captureImage(contentFilter: filter, configuration: configuration) imageView.image = NSImage(cgImage: windowImage, size: CGSize(width: windowImage.width, height: windowImage.height)) } } }

Since iOS 12 it has become difficult to detect the end of playback using the system music player. In earlier iOS versions, the now playing item would be set nil and you would receive a notification that the player stopped. In iOS 12 and later, nowPlayingItem still contains the current song and the only notification you get is MPMusicPlayerControllerPlaybackStateDidChangeNotification with the playbackState set to MPMusicPlaybackStatePaused. Pressing pause in my car (or any remote access) generates the same conditions making it difficult to correctly detect the difference. It would be nice if they added a notification that playback was done (similar to the other players). Any suggestions?

I am using MusicKit ApplicationMusicPlayer to play music in my app. Everything works fine as long as I'm not playing large playlists that contain hundreds of songs. When I to play collection of songs that is larger than around 300 I'm always getting the error message saying: "Prepare to play failed" UserInfo={NSDebugDescription=Prepare to play failed, NSUnderlyingError=0x121d42dc0 {Error Domain=MPMusicPlayerControllerErrorDomain Code=9 "Remote call timed out" UserInfo={NSDebugDescription=Remote call timed out}}})) It doesn't matter if songs are downloaded to the device or not. I am aware that there is another initializer for player's queue that accepts Playlist instances but in my app users can choose to sort playlist tracks in different order than the default and that makes using that initializer not feasible for me. I tried everything I could think of, I tried to fall back on MPMusicPlayerController and pass array of MPMusicPlayerPlayParameters to it but the result was the same. typealias QueueEntry = ApplicationMusicPlayer.Queue.Entry let player = ApplicationMusicPlayer.shared let entries: [QueueEntry] = tracks .compactMap { guard let song = $0 as? Song else { return nil } return QueueEntry(song) } Task(priority: .high) { [player] in do { player.queue = .init(entries, startingAt: nil) try await player.play() // prepareToPlay failed } catch { print(error) } }

In SwiftUI there is a built-in component for displaying album artworks called Artwork but there is no equivalent for UIKit. My current approach is to use the .url() method to read image's URL and download the image or read it from the disk but the performance is much worse than it was previously with MPMediaItem's artworkImage method. let artworkQueue = DispatchQueue( label: "MusicKit-ArtworkQueue", qos: .default, attributes: .concurrent ) let artworkSemaphore = DispatchSemaphore(value: 5) extension Song { func artworkImage(for size: CGSize, completion: @escaping (UIImage?) -> Void) { artworkQueue.async { artworkSemaphore.wait() defer { artworkSemaphore.signal() } let imageURL = artwork?.url( width: Int(size.width), height: Int(size.height) ) // I hate doing this as it might very well break in the future guard let imageURL, imageURL.scheme == "musicKit" else { return completion(nil) } guard let imageData = try? Data(contentsOf: imageURL), let image = UIImage(data: imageData) else { return completion(nil) } completion(image) } } } I really dislike this approach because it feels hacky but somewhat works. You might ask what's the semaphore for? Well, without it I could notice that MusicKit was choking and after reading too many artworks at once. Can someone from Apple please provide us with an example on how to use MusicKit with UIKit properly? Ideally (IMO) we would have a method defined on Song and other MusicKit structures that returns the image for us, just like MPMediaItem had the .artwork() method. It would make our lives so much easier.

I often find when doing basic actions in MusicKit it is incredibly slow compared to Apple's Music App. I've tried different versions, devices, networks, Apple's sample code, it all throughout the last several years, and it is all the same. Does anyone else have this issue?

I'm building a UIKit app that reads user's Apple Music library and displays it. In MusicKit there is the Artwork structure which I need to use to display artwork images in the app. Since I'm not using SwiftUI I cannot use the ArtworkImage view that is recommended way of displaying those images but the Artwork structure has a method that returns url for the image which can be used to read the image. The way I have it setup is really simple: extension MusicKit.Song { func imageURL(for cgSize: CGSize) -> URL? { return artwork?.url( width: Int(cgSize.width), height: Int(cgSize.height) ) } func localImage(for cgSize: CGSize) -> UIImage? { guard let url = imageURL(for: cgSize), url.scheme == "musicKit", let data = try? Data(contentsOf: url) else { return nil } return .init(data: data) } } Now, everytime I access .artwork property (so a lot of times) the main thread gets blocked and the console output gets bombared with messages like these: 2023-07-26 11:49:47.317195+0200 Plum[998:297199] [Artwork] Failed to create color analysis for artwork: <MPMediaLibraryArtwork: 0x289591590> with error; Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.mediaartworkd.xpc was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.mediaartworkd.xpc was invalidated: failed at lookup with error 159 - Sandbox restriction.} 2023-07-26 11:49:47.317262+0200 Plum[998:297199] [Artwork] Failed to create color analysis for artwork: file:///var/mobile/Media/iTunes_Control/iTunes/Artwork/Originals/4b/48d7b8d349d2de858413ae4561b6ba1b294dc7 2023-07-26 11:49:47.323099+0200 Plum[998:297013] [Plum] IIOImageWriteSession:121: cannot create: '/var/mobile/Media/iTunes_Control/iTunes/Artwork/Caches/320x320/4b/48d7b8d349d2de858413ae4561b6ba1b294dc7.sb-f9c7943d-6ciLNp'error = 1 (Operation not permitted) My guess is that the most performance-heavy task here is performing the color analysis for each artwork but IMO the property backgroundColor should not be a stored property if that's the case. I am not planning to use it anywhere and if so it should be a computed async property so it doesn't block the caller. I know I can move the call to a background thread and that fixes the issue of blocking main thread but still the loading times for each artwork are terribly slow and that impacts the UX. SwiftUI's ArtworkImage loads the artworks much quicker and without the errors so there must be a better way to do it.

Add RPSystemBroadcastPickerView to the app, After clicking, no method of SampleHandler is triggered

The two ScreenCaptureKit WWDC22 sessions show how to capture with the new framework but the retina factor is hardcoded to 2 in SCStreamConfiguration. When using on a non-retina display, the screencapture is floating on the upper-left corner of the image buffer. There does not seem to be a simple way to retrieve the retina factor from the SCShareableContent data (when configuring the capture). When processing the streaming output, the SCStreamFrameInfo attachment is supposed to have a scaleFactor property but .scaleFactor does not return a value. I have found out that the attachement dictionary contains SCStreamUpdateFrameDisplayResolution. This entry gives me the retina factor but it is not an official SCStreamFrameInfo key. I list the keys to access it. What is the proper way with ScreenCapture to handle the retina factors ?

Hi all,  Apple dropping on-going development for FireWire devices that were supported with the Core Audio driver standard is a catastrophe for a lot of struggling musicians who need to both keep up to date on security updates that come with new OS releases, and continue to utilise their hard earned investments in very expensive and still pristine audio devices that have been reduced to e-waste by Apple's seemingly tone-deaf ignorance in the cries for on-going support.  I have one of said audio devices, and I'd like to keep using it while keeping my 2019 Intel Mac Book Pro up to date with the latest security updates and OS features.  Probably not the first time you gurus have had someone make the logical leap leading to a request for something like this, but I was wondering if it might be somehow possible of shoe-horning the code used in previous versions of Mac OS that allowed the Mac to speak with the audio features of such devices to run inside the Ventura version of the OS.  Would it possible? Would it involve a lot of work? I don't think I'd be the only person willing to pay for a third party application or utility that restored this functionality. There has to be 100's of thousands of people who would be happy to spare some cash to stop their multi-thousand dollar investment in gear to be so thoughtlessly resigned to the scrap heap.  Any comments or layman-friendly explanations as to why this couldn’t happen would be gratefully received!  Thanks,  em

Hello, I'm new to the Swift MusicKit API and am starting with the implementation in iOS 16. I'm getting stuck on an issue where there is no background or text color associated with the Artwork object. Is this something you have to make an additional property request for, and if so, how do you do that? var catalogSearch = MusicCatalogResourceRequest<Album>(matching: \.id, equalTo: item.id) let catalogResponse = try await request.response() guard let firstItem = catalogResponse.items.first else { return } In this example, firstItem.artwork only contains the url and what look like incorrect max width/height values. here's a printout of firstItem.artwork Optional(Artwork(   urlFormat: "musicKit://artwork/library/5F37858D-F46B-4F12-BA67-40FA8DD63D87/{w}x{h}?at=item&fat=&id=7718670444435992305&lid=5F37858D-F46B-4F12-BA67-40FA8DD63D87&mt=music&aat=Music122/v4/37/25/f5/3725f515-249f-7b91-77bb-f479cd48201c/22UMGIM32254.rgb.jpg", maximumWidth: 0, maximumHeight: 0 ))

I've just begun to dip my toes into the iOS16 waters. One of the first things that I've attempted is to edit a library playlist using: try await MusicLibrary.shared.edit(targetPlaylist, items: tracksToAdd) Where targetPlaylist is of type MusicItemCollection<MusicKit.Playlist>.Element and tracksToAdd is of type [Track] The targetPlaylist was created, using new iOS16 way, here: let newPlaylist = try await MusicLibrary.shared.createPlaylist(name: name, description: description) tracksToAdd is derived by performing a MusicLibraryRequest on a specific playlist ID, and then doing something like this: if let tracksToAdd = try await playlist.with(.tracks).tracks {    // add tracks to target playlist } My problem is that when I perform attempt the edit, I am faced with a rather sad looking crash. libdispatch.dylib`dispatch_group_leave.cold.1:     0x10b43d62c <+0>:  mov    x8, #0x0     0x10b43d630 <+4>:  stp    x20, x21, [sp, #-0x10]!     0x10b43d634 <+8>:  adrp   x20, 6     0x10b43d638 <+12>: add    x20, x20, #0xfbf          ; "BUG IN CLIENT OF LIBDISPATCH: Unbalanced call to dispatch_group_leave()"     0x10b43d63c <+16>: adrp   x21, 40     0x10b43d640 <+20>: add    x21, x21, #0x260          ; gCRAnnotations     0x10b43d644 <+24>: str    x20, [x21, #0x8]     0x10b43d648 <+28>: str    x8, [x21, #0x38]     0x10b43d64c <+32>: ldp    x20, x21, [sp], #0x10 ->  0x10b43d650 <+36>: brk    #0x1 I assume that I must be doing something wrong, but I frankly have no idea how to troubleshoot this. Any help would be most appreciated. Thanks. @david-apple?

Just wondering if anyone else is having issues with currentPlaybackRate in release version of iOS 15.4? In my particular case this is using MPMusicPlayerController.applicationQueuePlayer. I've always had issues controlling this property reliably but from what I can see it is now completely non-operational in 15.4. I've isolated this behavior in a trivial project, and will file a radar, but hoping others may have some insight first. FWIW- This is my trivial test case: class ViewController: UIViewController {     lazy var player: MPMusicPlayerApplicationController = {         let player = MPMusicPlayerController.applicationQueuePlayer         player.repeatMode = .none         player.shuffleMode = .off         player.beginGeneratingPlaybackNotifications()         return player     }()     override func viewDidLoad() {         super.viewDidLoad()         NotificationCenter.default.addObserver(forName: .MPMusicPlayerControllerPlaybackStateDidChange, object: nil, queue: .main) { [weak self] notification in             guard let notificationPlayer = notification.object as? MPMusicPlayerApplicationController,                   notificationPlayer === self?.player else {                 return             }                          debugPrint("Player state now: \(notificationPlayer.playbackState)")         }     }     @IBAction func goAction(_ sender: Any) {         guard let item = MPMediaQuery.songs().items?.randomElement() else {             debugPrint("Unable to access media items")             return         }         debugPrint("Now playing item: \(item.title ?? "")")         player.setQueue(with: [item.playbackStoreID])         player.prepareToPlay() { error in             guard error == nil else {                 debugPrint("Player error: \(error!.localizedDescription)")                 return             }             DispatchQueue.main.async { [weak self] in                 self?.player.play()             }         }     } @IBAction func slowAction(_ sender: Any) {         debugPrint("Setting currentPlaybackRate to 0.5")         player.currentPlaybackRate = 0.5         checkPlaybackRate()     } @IBAction func fastAction(_ sender: Any) {         debugPrint("Setting currentPlaybackRate to 1.5")         player.currentPlaybackRate = 1.5         checkPlaybackRate()     } func checkPlaybackRate(afterSeconds delay: TimeInterval = 1.0) {         DispatchQueue.main.asyncAfter(deadline: .now() + delay) {             debugPrint("After \(delay) seconds currentPlaybackRate now: \(self.player.currentPlaybackRate)")         }     } } Typical console output: "Now playing item: I Know You Know" "Player state now: MPMusicPlaybackState(rawValue: 2)" "Player state now: MPMusicPlaybackState(rawValue: 1)" "Setting currentPlaybackRate to 1.5" "After 1.0 seconds currentPlaybackRate now: 1.0" "Setting currentPlaybackRate to 0.5" "After 1.0 seconds currentPlaybackRate now: 1.0"

Has anyone been able to successfully use MusicCatalogSearchRequest in a playgrounds app? I have configured my playground similar to a regular app: app id with automatic music token generation turned on, music access authorized within the app itself, but whenever I query MusicCatalogSearchRequest I get an error thrown with .developerTokenRequestFailed. Considering musickit is restricted in the sim, it would not surprise me if it was the same in playgrounds but it would be super helpful if I could prototype with musickit in playgrounds 4!