I ran 5.1 audio tests in both YouTube and Apple Music, and I noticed that when sound is supposed to play from the rear or front surround speakers, it’s also duplicated in the front left and right channels. I’m absolutely sure the issue is with the Apple TV, because I played the same video directly through my TV’s native system, and the channel separation was correct. Everything used to work perfectly before, so this must be a software issue. I’m currently on tvOS 26 Developer Beta 5, but I’m certain the problem also existed on the stable tvOS 18.5. I’ve already reset and updated my Apple TV, and I also tried switching the audio format to forced Dolby Atmos 5.1. On the forums, I mostly see complaints about Dolby Atmos not working at all — in my case, everything technically works, but not the way it’s supposed to.

Hello, I need to enumerate built-in media devices (cameras, microphones, etc.). For this purpose, I am using the CoreAudio and CoreMediaIO frameworks. According to the table 'Daemon-Safe Frameworks' in Apple’s TN2083, CoreAudio is daemon-safe. However, the documentation does not mention CoreMediaIO. Can CoreMediaIO be used in a daemon? If not, are there any documented alternatives to detect built-in cameras in a daemon (e.g., via device classes in IOKit)? Thank you in advance, Pavel

On an iPhone running iOS 26 beta 5, url(for: FilePath("subdir/asset.mov")) most always throws this error: The URL for “subdir/asset.mov” couldn’t be retrieved: “asset.mov” couldn’t be copied to “subdir” because an item with the same name already exists. Yet, contents(at: FilePath("subdir/asset.mov")) always returns Data for a playable AVMovie. How can I avoid this url(for:) error? The asset pack in question is downloaded. The error persists even after pack deletion, redownload, relaunch, and combinations of that. // Assets repo root subdir.aar subdir/asset.mov subdir/asset_thumb.heic subdir/Manifest.json // Manifest.json { "assetPackID": "subdir", "downloadPolicy": { "onDemand": {} }, "fileSelectors": [ { "directory": "subdir", }, ], "platforms": [ "iOS", "visionOS" ] } xcrun ba-package subdir/Manifest.json -o subdir.aar xcrun ba-serve --host 192.168.0.10 -p 443 subdir.aar

I might have misunderstood the docs, but is Call Translation going to be available for VOIP applications? Eg in an already connected VOIP call, would it be possible for Call Translations to be enabled on an iOS 26 and Apple Intelligence supported device? I have personally tried it and it doesn’t look like it supported VOIP but would love to confirm this. reference: https://developer.apple.com/documentation/callkit/cxsettranslatingcallaction/

I’m an amateur developer working on a free utility for composers/producers, for which the macOS release needs to create and name RTP-MIDI sessions in Audio MIDI Setup from the command line (so I can ship a small C helper instead of telling users to click through the UI). Here’s what I’ve tried so far, without luck: • Plist hacks: Injecting entries into ~/Library/Audio/MIDI Configurations/*.mcfg works when AMS is closed, but AMS immediately locks and reverts my changes when it’s open. • CoreMIDI C API: I can create virtual ports with MIDISourceCreate, but attempting MIDIObjectGetDataProperty on the apple.midirtp.session plugin always returns err –10836. • Obj-C & Swift: Loading MIDINetworkSession and calling defaultSession, init, setNetworkName: and setting enabled = YES doesn’t produce a new session object in the Network panel. • dlopen/dlsym: I extracted the real CoreMIDI binary out of the dyld shared cache and tried binding _MIDINetworkSessionCreate, _SetName, _SetEnabled, etc., but all the symbols come back null or my tool segfaults. • Plugin registration: I’ve pulled the factory UUID (70C9C5EA-7C65-11D8-B317-000393A34B5A) from /System/Library/Extensions/AppleMIDIRTPDriver.plugin/Contents/Info.plist and called CFPlugInRegisterFactories, but it still never exposes the session-creation calls. At this point I’m convinced I’m either loading the wrong binary or missing one critical step in registering the RTP-MIDI plugin’s private API. Can anyone point me to: The exact path of the dylib or bundle that actually exports the MIDINetworkSessionCreate/MIDINetworkSessionSetName/MIDINetworkSessionSetEnabled symbols? A minimal working snippet (C or Obj-C) that reliably creates and names a Network-MIDI session? Any pointers, sample code, or even ideas about where Apple hides this functionality on macOS 15 would be hugely appreciated. Thanks!

ApplicationMusicPlayer is not available on watchOS but all other platforms. Is there a technical reason for that like battery life? Same goes for SystemMusicPlayer and MPMusicPlayerController. I already filed feedbacks for that.

We are facing a strange issue where a small portion of our large userbase can not start the capture session in our app, as it gets interrupted with the following reason: AVCaptureSessionInterruptionReasonVideoDeviceNotAvailableWithMultipleForegroundApps Our users are all from iPhones, no one is using an iPad. Just to be sure we have set session.isMultitaskingCameraAccessEnabled = true but it does not seem to make any difference. Another weird scenario we are seeing on an even smaller number of users is that the following call: AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back) returns nil. A quick look at our error reports show this happening on iPhone XR, 13 and 14 models. They should all support this device type. Any help on investigating these issue would be greatly appreciated!

i have a wallpaper app , i need a photos access when i try to add it in capabilities i don't find it.is there any solution?

Hi, I’ve developed a photo app that includes a photo deletion feature. Some users have reported encountering PHPhotosError.operationInterrupted (3301) when attempting to delete photos. Initially, I suspected that some of the assets might have a sourceType of typeiTunesSynced, since the documentation notes that iTunes-synced assets cannot be edited or deleted. However, after checking the logs, all of the assets involved are of typeUserLibrary. Additionally, the user mentioned that some photos in the iPhone Photos do not show a delete button. I’m unsure whether the absence of the delete button is related to the 3301 error. I’d like to confirm the following: Under what conditions does PHPhotosError.operationInterrupted (3301) occur, and how should it be handled? Why do some photos in the iPhone Photos not show a delete button? The code for deleting photos is as follows: PHPhotoLibrary *library = [PHPhotoLibrary sharedPhotoLibrary]; [library performChanges:^{ PHFetchResult *assetsToBeDeleted = [PHAsset fetchAssetsWithLocalIdentifiers:delUrls options:nil]; if (assetsToBeDeleted) { [PHAssetChangeRequest deleteAssets:assetsToBeDeleted]; } } completionHandler:^(BOOL success, NSError *error) {

The documentation of the Apple Music Feed API states that the Album object would include songs — a list of songs in the album. As per the doc, this would be an array of object Album.RelatedSong, which would include both an id and nameDefault. Unfortunately, the album parquet files only include the song id and not the name of the song itself. Please advise - is the documentation incorrect or are the recently posted parquet files in error?

A recent WWDC session "Learn about Apple Immersive Video technologies" showed a Apple Spatial Audio Format Panner plugin for Pro Tools. The presenter stated that it's available on a per-user license. Where can users access this?

The documentation for PHAssetChangeRequest.revertAssetContentToOriginal says it will fail if the original asset content is not on the current device so you should use PHAssetResourceManager to download it first, but this no longer seems to be the case in the latest iOS versions because an error no longer occurs when I take a photo on my iPhone, edit it, open Photos on my iPad and let it sync, then open my app on iPad and call revertAssetContentToOriginal for that asset. Does the system now take care of downloading the original when needed?

Hi, I'm developing an application for macos and ios that has to run DetectHumanBodyPose3DRequest model in real time for retrieving the 3d skeleton from the camera. I'm experiencing a memory leak every time the model is used (when i comment that line, the memory stays constant). After a minute it uses about 1GB of ram running with mac catalyst. I attached a minimal project that has this problem Code Camera View import SwiftUI import Combine import Vision struct CameraView: View { @StateObject private var viewModel = CameraViewModel() var body: some View { HStack { ZStack { GeometryReader { geometry in if let image = viewModel.currentFrame { Image(decorative: image, scale: 1) .resizable() .scaledToFill() .frame(width: geometry.size.width, height: geometry.size.height) .clipped() } else { ProgressView() } } } } } } class CameraViewModel: ObservableObject { @Published var currentFrame: CGImage? @Published var frameRate: Double = 0 @Published var currentVisionBodyPose: HumanBodyPose3DObservation? // Store current body pose @Published var currentImageSize: CGSize? // Store current image size private var cameraManager: CameraManager? private var humanBodyPose = HumanBodyPose3DDetector() private var lastClassificationTime = Date() private var frameCount = 0 private var lastFrameTime = Date() private let classificationThrottleInterval: TimeInterval = 1.0 private var lastPoseSendTime: Date = .distantPast init() { cameraManager = CameraManager() startPreview() startClassification() } private func startPreview() { Task { guard let previewStream = cameraManager?.previewStream else { return } for await frame in previewStream { let size = CGSize(width: frame.width, height: frame.height) Task { @MainActor in self.currentFrame = frame self.currentImageSize = size self.updateFrameRate() } } } } private func startClassification() { Task { guard let classificationStream = cameraManager?.classificationStream else { return } for await pixelBuffer in classificationStream { self.classifyFrame(pixelBuffer: pixelBuffer) } } } private func classifyFrame(pixelBuffer: CVPixelBuffer) { humanBodyPose.runHumanBodyPose3DRequestOnImage(pixelBuffer: pixelBuffer) { [weak self] observation in guard let self = self else { return } DispatchQueue.main.async { if let observation = observation { self.currentVisionBodyPose = observation print(observation) } else { self.currentVisionBodyPose = nil } } } } private func updateFrameRate() { frameCount += 1 let now = Date() let elapsed = now.timeIntervalSince(lastFrameTime) if elapsed >= 1.0 { frameRate = Double(frameCount) / elapsed frameCount = 0 lastFrameTime = now } } } HumanBodyPose3DDetector import Foundation import Vision class HumanBodyPose3DDetector: NSObject, ObservableObject { @Published var humanObservation: HumanBodyPose3DObservation? = nil private let queue = DispatchQueue(label: "humanbodypose.queue") private let request = DetectHumanBodyPose3DRequest() private struct SendablePixelBuffer: @unchecked Sendable { let buffer: CVPixelBuffer } public func runHumanBodyPose3DRequestOnImage(pixelBuffer: CVPixelBuffer, completion: @escaping (HumanBodyPose3DObservation?) -> Void) { let sendableBuffer = SendablePixelBuffer(buffer: pixelBuffer) queue.async { [weak self] in Task { [weak self, sendableBuffer] in do { guard let self = self else { return } let result = try await self.request.perform(on: sendableBuffer.buffer) //process result DispatchQueue.main.async { if result.isEmpty { completion(nil) } else { completion(result[0]) } } } catch { DispatchQueue.main.async { completion(nil) } } } } } }

Hi, I am trying to remove the audio controls for my app on the lock screen. Since I use WKWebView, there are 3 audio tags in my html and I play and pause em via JS. However, if I do not play any sound since app launch, there are no audio controls on the lock screen. But if I play one of those 3 files (they are even less then 3 Sec sound effects e.g. for buttons) the audio controls appears on lock screen. Note even when the sounds on pause() or not playing they were listed on the lock screen. What I have tried so far without success MPNowPlayingInfoCenter.default().nowPlayingInfo = [:] and ``try audioSession.setCategory(.playback, mode: .default, options: []) try audioSession.setActive(false, options: .notifyOthersOnDeactivation)`` and UIApplication.shared.endReceivingRemoteControlEvents() Another problem is that the app scales with iOS system settings "display zoom". Is there a way to deny it? It is latest Xcode verion 16.3 and iOS 18. I have no background mode in my Capabilities. Nothing worked so far. Has anyone an idea? Greetings

Hello. My app uses AVAudioRecorder to generate recording files, which are consistently only 4kb in size. Most users generate audio files normally, with only a few users experiencing this phenomenon occasionally. After uninstalling and installing the app, it will work normally, but it will reappear after a period of time. I have compared that the problematic audio files generated each time are fixed and cannot be played. Added the audioRecorderDidFinishRecording proxy method, which shows that the recording was completed normally. The user also reported that the recording is normal, but there is a problem with the generated file. How should I handle this issue? Look forward to your reply. - (void)startRecordWithOrderID:(NSString *)orderID { AVAudioSession *audioSession = [AVAudioSession sharedInstance]; [audioSession setCategory:AVAudioSessionCategoryRecord error:nil]; [audioSession setActive:YES error:nil]; NSMutableDictionary *settings = [[NSMutableDictionary alloc] init]; [settings setObject:[NSNumber numberWithFloat: 8000.0] forKey:AVSampleRateKey]; [settings setObject:[NSNumber numberWithInt: kAudioFormatLinearPCM] forKey:AVFormatIDKey]; [settings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey]; [settings setObject:[NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey]; [settings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey]; [settings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey]; NSString *path = [WDUtility createDirInDocument:@"audios" withOrderID:orderID withPathExtension:@"wav"]; NSURL *tmpFile = [NSURL fileURLWithPath:path]; recorder = [[AVAudioRecorder alloc] initWithURL:tmpFile settings:settings error:nil]; [recorder setDelegate:self]; [recorder prepareToRecord]; [recorder record]; }

There appears to be no method of going forward or backwards in Get Info in the Music application,

PLATFORM AND VERSION :iOS 18.5 I wanted to bring to your attention a critical issue some of our production users are experiencing with the CoinOut app. Specifically, users are encountering a problem when attempting to capture photos of receipts using the app's customized camera feature. The camera, which utilizes AVCaptureVideoPreviewLayer and AVCaptureDevice, occasionally fails to load the preview, resulting in a black screen instead of the expected camera view. This camera blackout issue is significantly impacting the user experience as it prevents them from snapping photos of their receipts, which is a core functionality of the CoinOut app. Any help/suggestion to this issue would be greatly appreciated. STEPS TO REPRODUCE Open the app and click on camera icon. It will display camera to capture photo. Camera shows black for few production user's. class ViewController: UIViewController { @IBOutlet private weak var captureButton: UIButton! private var fillLayer: CAShapeLayer! private var previewLayer : AVCaptureVideoPreviewLayer! private var output: AVCapturePhotoOutput! private var device: AVCaptureDevice! private var session : AVCaptureSession! private var highResolutionEnabled: Bool = false private let sessionQueue = DispatchQueue(label: "session queue") override func viewDidLoad() { super.viewDidLoad() setupCamera() customiseUI() } @IBAction func startCamera(sender: UIButton) { didTapTakePhoto() } private func setupCamera() { let session = AVCaptureSession() session.sessionPreset = AVCaptureSession.Preset.high previewLayer = AVCaptureVideoPreviewLayer(session: session) output = AVCapturePhotoOutput() device = AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .back) if let device = self.device{ do{ let input = try AVCaptureDeviceInput(device: device) if session.canAddInput(input){ session.addInput(input)} else { print("\(#fileID):\(#function):\(#line) : Session Input addition failed") } if session.canAddOutput(output){ output.isHighResolutionCaptureEnabled = self.highResolutionEnabled session.addOutput(output) } else { print("\(#fileID):\(#function):\(#line) : Session Input high resolution failed") } previewLayer.videoGravity = .resizeAspectFill previewLayer.session = session sessionQueue.async { session.startRunning() } self.session = session self.session.accessibilityElementIsFocused() try device.lockForConfiguration() if device.isWhiteBalanceModeSupported(AVCaptureDevice.WhiteBalanceMode.autoWhiteBalance) { device.whiteBalanceMode = .autoWhiteBalance } else { print("\(#fileID):\(#function):\(#line) : isWhiteBalanceModeSupported no supported") } if device.isWhiteBalanceModeSupported(AVCaptureDevice.WhiteBalanceMode.continuousAutoWhiteBalance) { device.whiteBalanceMode = .continuousAutoWhiteBalance } else { print("\(#fileID):\(#function):\(#line) : isWhiteBalanceModeSupported no supported") } if device.isFocusModeSupported(.continuousAutoFocus) { device.focusMode = .continuousAutoFocus} else if device.isFocusModeSupported(.autoFocus) { device.focusMode = .autoFocus } device.unlockForConfiguration() } catch { print("\(#fileID):\(#function):\(#line) : \(error.localizedDescription)") } } else { print("\(#fileID):\(#function):\(#line) : Device found as nil") } } private func customiseUI() { let path = UIBezierPath(roundedRect: CGRect(x: 0, y: 0, width: self.view.bounds.width, height: self.view.bounds.height), cornerRadius: 0) let rectangleWidth = view.frame.width - (view.frame.width * 0.16) let x = (view.frame.width - rectangleWidth) / 2 let rectangleHeight = view.frame.height - (view.frame.height * 0.16) let y = (view.frame.height - rectangleHeight) / 2 let roundRect = UIBezierPath(roundedRect: CGRect(x: x, y: y, width: rectangleWidth, height: rectangleHeight), byRoundingCorners:.allCorners, cornerRadii: CGSize(width: 0, height: 0)) roundRect.move(to: CGPoint(x: self.view.center.x , y: self.view.center.y)) path.append(roundRect) path.usesEvenOddFillRule = true fillLayer = CAShapeLayer() fillLayer.path = path.cgPath fillLayer.fillRule = .evenOdd fillLayer.opacity = 0.4 previewLayer.addSublayer(fillLayer) previewLayer.frame = view.bounds view.layer.addSublayer(previewLayer) view.bringSubviewToFront(captureButton) } private func didTapTakePhoto() { let settings = self.getSettings(camera: self.device) if device.isAdjustingFocus { do { try device.lockForConfiguration() device.focusMode = .continuousAutoFocus device.unlockForConfiguration() device.addObserver(self, forKeyPath: "adjustingFocus", options: [.new], context: nil) } catch { print(error) } } else { output.capturePhoto(with: settings, delegate: self) } } func getSettings(camera: AVCaptureDevice) -> AVCapturePhotoSettings { var settings = AVCapturePhotoSettings() if let rawFormat = output.availableRawPhotoPixelFormatTypes.first { settings = AVCapturePhotoSettings(rawPixelFormatType: OSType(rawFormat)) } settings.isHighResolutionPhotoEnabled = self.highResolutionEnabled let previewPixelType = settings.availablePreviewPhotoPixelFormatTypes.first! let previewFormat = [kCVPixelBufferPixelFormatTypeKey as String: previewPixelType] as [String : Any] settings.previewPhotoFormat = previewFormat return settings } } extension ViewController: AVCapturePhotoCaptureDelegate { func photoOutput(_ output: AVCapturePhotoOutput, willCapturePhotoFor resolvedSettings: AVCaptureResolvedPhotoSettings) { AudioServicesDisposeSystemSoundID(1108) } func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) { guard let data = photo.fileDataRepresentation() else { return } let image = UIImage(data: data)! showImage(cropped: image) } func showImage(cropped: UIImage) { let vc = self.storyboard?.instantiateViewController(withIdentifier: "ImagePreviewViewController") as? ImagePreviewViewController vc?.captured = cropped self.present(vc!, animated: true) } }```

(Note: this is part 2 of a 3 part posting. See Part 1 or Part 3) At WWDC25 we launched a new type of Lab event for the developer community - Group Labs. A Group Lab is a panel Q&A designed for a large audience of developers. Group Labs are a unique opportunity for the community to submit questions directly to a panel of Apple engineers and designers. Here are the highlights from the WWDC25 Group Lab for Camera & Photos. WWDC25 Camera & Photos group lab ran for one hour at 6 PM PST on Tuesday June 10th, 2025 Question 10 Can we directly integrate auto-capture triggers (e.g., when image is steady or text is detected) using Vision and AVFoundation? Yes apps can use AVCaptureSession's VDO + AVCapturePhotoOutput, run vision on VDO buffers and capture photo when certain scene or text is detected. Just to be careful to run Vision on VDO buffers async so it doesn't cause frame drops. Question 11 What Camera or Photos framework features support working with images from external media, like connected cameras or SD cards? Any best practices? The ImageCaptureCore framework supports camera devices, memory cards, scanners read and write, where supported check out the docs to see how to browse connected devices, folders, files, etc. Question 12 Hi Brad, to follow up on your SwiftUI cautionary note: using AVCaptureVideoPreview inside a UIViewRepresentable, is okay, right? Thanks all for the great info! Yes, this is totally fine. AppKit or UIKit views inside appropriate SwiftUI representables should be equivalent performance Question 13 What’s the “right” way to transition media in my photos app between HDR modes? When I’m in a one-up view, we use HDR, but in other contexts (like thumbnail) we don’t want HDR. Is there a nice way to tone map? There’s a suite of new System Tone Mapper APIs in this years’ OSes CoreImage ImageKit CoreAnimation, CoreGraphics For example: CoreImage: new CISystemToneMap filter. CoreAnimation: layer.preferredDynamicRange = CADynamicRangeConstrainedHigh Using image views (NSImageView/UIImageView/SwiftUI Image/CALayer) support animations on preferredDynamicRange Can go from high to constrained to standard Tone mapping is provided by the system (CISystemToneMap for controllable example) Question 14 What is your recommendation to preprocess and upscale your depth map in order to render a realistic portrait mode image? One way to do this: the CIEdgePreserveUpsample CIFilter can be use to upsample a lower resolution depth map by using a higher resolution RGB image as a guide. Question 15 For buffering frames for later processing from real-time camera output should we prefer a AVSampleBufferDisplayLayer centered approach or AVCaptureVideoDataOutputSampleBufferDelegate centered approach? When would we use each? AVSampleBufferDisplayLayer and AVCaptureVideoDataOutputSampleBufferDelegate are used hand in hand for custom camera preview. For buffering for later processing, ensure you make copies of VDO buffers to not drop frames from the output Question 16 Hello, my question is on Deferred Photo Processing? Say I have a photo capture app that adds a CIFilter to the capture. How can I take advantage of Deferred Photo Processing? Since I don’t know how to detect when the deferred captured photo is ready CIFilter can be called on the final at that point Photo will have to be re-inserted into the Photo library as adjustment Question 17 Is digital zoom (e.g., 1.5x) before taking a photo the same as cropping the photo afterward? digital zoom upscales the image to output dimensions and cropping will yield a smaller output image while digital zoom will crop, it also upscales Question 18 How do you design camera interfaces that work for both casual users and photography enthusiasts? Progressive disclosure: Put the most common controls up front, and make it easy for pros to drill down. Sensible Defaults: Choose defaults that work well for casual users, but allow those defaults to be modified for photography enthusiasts A good philosophy is: Keep the simple things easy, make the hard things possible Question 19 Recent iPhone models introduced macro mode which automatically switch between lenses to take into account of the focal distance difference. Is there official API to implement this, or should I implement them myself using LiDAR values. Using builtInTripleCamera and builtInDualWideCamera will automatically switch to macro when available Question 20 a couple of years ago at WWDC, the option of replacing a camera with a virtual camera was mentioned. How does one do that - make the “physical” camera effectively disappear, so only the virtual camera is accessible to the user? You can't prevent the built-in camera from being available to the user Question 21 Can developers now integrate custom Core ML models with Vision for on-device photo analysis more seamlessly? Yes they can, use CoreMLRequest , provide their model container Been supported for a while (iOS 18/macOS 15) For more details go to Machine Learning & AI group lab Thursday use smaller images for better performance Question 22 What would you recommend for capture of the new immersive and spatial formats? To capture Spatial Video use AVCaptureMovieFileOutput’s spatialVideoCaptureEnabled property Not all device formats support spatial capture, check AVCaptureDevice.activeFormat.spatialVideoCaptureSupported See WWDC 2024 talk “Build compelling spatial photo and video experiences” for more details Question 23 You mentioned JPEG-XL. What is the current status of support on iOS and macOS for encoding and decoding? For decoding, we support JPEG-XL files in all our OSes, regular SDR files, as well as ISO HDR files. For encoding, we only support JPEG-XL for ProRAW DNG capture in the Camera app or via third-party AVFoundation APIs. If you have any requests for improvement or new features related to JPEG-XL, please file a Feedback request using the Feedback Assistant. (Note: this is part 2 of a 3 part posting. See Part 1 or Part 3)

iOS 26 added smoothness to CIRoundedRectangleGenerator, for use with CIFilter.roundedRectangleGenerator. What should the smoothness value be to achieve the same corner curve as CALayerCornerCurve.continuous? Does it need to be calculated based on the extent size, if so, how?

Hello everyone, I’m new to Swift development and have been working on an audio module that plays a specific sound at regular intervals - similar to a workout timer that signals switching exercises every few minutes. Following AVFoundation documentation, I’m configuring my audio session like this: let session = AVAudioSession.sharedInstance() try session.setCategory( .playback, mode: .default, options: [.interruptSpokenAudioAndMixWithOthers, .duckOthers] ) self.engine.attach(self.player) self.engine.connect(self.player, to: self.engine.outputNode, format: self.audioFormat) try? session.setActive(true) When it’s time to play cues, I schedule playback on a DispatchQueue: // scheduleAudio uses DispatchQueue self.scheduleAudio(at: interval.start) { do { try audio.engine.start() audio.node.play() for sample in interval.samples { audio.node.scheduleBuffer(sample.buffer, at: AVAudioTime(hostTime: sample.hostTime)) } } catch { print("Audio activation failed: \(error)") } } This works perfectly in the foreground. But once the app goes into the background, the scheduled callback runs, yet the audio engine fails to start, resulting in an error with code 561015905. Interestingly, if the app is already playing audio before going to the background, the scheduled sounds continue to play as expected. I have added the required background audio mode to my Info plist file by including the key UIBackgroundModes with the value audio. Is there anything else I should configure? What is the best practice to play periodic audio when the app runs in the background? How do apps like turn-by-turn navigation handle continuous audio playback in the background? Any advice or pointers would be greatly appreciated!