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Crash in iOS 18 regarding [AVPlayerController _observeValueForKeyPath:oldValue:newValue:]
There are significant crash reports coming from iOS 18 users regarding AVKit framework that starts from this line [AVPlayerController _observeValueForKeyPath:oldValue:newValue:] which seems to be coming from iOS internal SDK. There are 2 kinds of crash we found: UI modification on background thread From the stack trace it seems like when AVPictureInPictureController is being deallocated and its view is being removed from superview somehow the code is being executed in background thread because there is this line there _AssertAutoLayoutOnAllowedThreadsOnly highlighted before the crash. But I’ve checked our code that plays around AVPictureInPictureController, in the locations where we would deallocate the object it will always be called on main thread which are insideviewDidLoad and deinit inside UIViewController class. From the log, it seems like the crash happened when user try to open another content when PIP player is active resulting in the current PIP instance will be replaced with a new one. My suspect is the observation logic inside AVPlayerController could be the hint to this issue, probably something broken over there since this issue happened across our app versions on iOS 18 users only. Unfortunately, I was unable to reproduce this issue yet but one of my colleagues reproduced it once but haven’t been able to do it again since. The reports keep raising each day up to 1.3k events in the last 30 days now. Over release object This one has lower reports than the first one but I decided to include it since it might have relevant information regarding the first crash since the starting stack trace is similar. The crash timing seems to be similar to the first one, where we deallocate existing AVPictureInPictureController and later replace it with a new one and also found only in iOS 18 users which also refers to [AVPlayerController _observeValueForKeyPath:oldValue:newValue:]. I also was unable to reproduce this issue so far. Oh, and both of the issues happened on both iPhone and iPad. We’d appreciate any advice on what we can do to avoid this in the future and probably any hint on why it could happened. I have reported this issue with bug number: FB15620734 I also attached one sample crash report for each of the crashes here. non ui thread access.crash over release.crash
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2.8k
Jun ’25
ShazamKit supported for iOS apps that can run on Mac silicon?
I am having issues deploying my iOS app, that uses ShazamKit, to get working on a Mac with Apple silicon. When uploading the archive to App Store Connect I do get ITMS-90863: Macs with Apple silicon support issue - The app links with libraries that aren’t present in macOS: /usr/lib/swift/libswiftShazamKit.dylib Is ShazamKit not supported for iOS apps that can run on Macs with Apple silicon? Or is there something I should fix in my setup / deployment?
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1.3k
Jun ’25
WWDC25 Camera & Photos group lab summary (Part 2 of 3)
(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)
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485
Jul ’25
Mic audio before and after a call is answered
I have an app that records a health provider’s conversation with a patient. I am using Audio Queue Services for this. If a phone call comes in while recording, the doctor wants to be able to ignore the call and continue the conversation without touching the phone. If the doctor answers the call, that’s fine – I will stop the recording. I can detect when the call comes in and ends using CXCallObserver and AVAudioSession.interruptionNotification. Unfortunately, when a call comes in and before it is answered or dismissed, the audio is suppressed. After the call is dismissed, the audio continues to be suppressed. How can I continue to get audio from the mic as long as the user does not answer the phone call?
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84
May ’25
AVFoundation — MJPEG Custom-Resolution UVC Stream Not Working on macOS
Hello, I'm Soonwon. We’re currently developing a UVC camera device and trying to stream MJPEG video via AVFoundation on macOS. However, we’re running into a problem with custom resolutions. When we try to use AVFoundation on macOS to capture MJPEG video at 1000x6000, the stream is not accepted or simply doesn’t work. Lower resolutions work fine. (Interestingly, using the same device on iPadOS, we can capture the 1000x6000 MJPEG stream successfully by using AVCaptureSessionPresetInputPriority.) Is there any way to receive custom-resolution MJPEG streams (like 1000x6000) from a UVC device using AVFoundation on macOS? Are there specific session presets, entitlements, or known limitations that affect MJPEG handling at custom resolutions on macOS? Does macOS handle MJPEG differently from iPadOS in AVFoundation? Any insight or guidance would be greatly appreciated. Thank you! NSError *error = nil; if ([selectedDevice lockForConfiguration:&error]) { [session beginConfiguration]; session.sessionPreset = AVCaptureSessionPresetHigh; bool foundFormat = false; for (AVCaptureDeviceFormat *format in selectedDevice.formats) { CMVideoDimensions dims = CMVideoFormatDescriptionGetDimensions(format.formatDescription); FourCharCode pixelFormat = CMFormatDescriptionGetMediaSubType(format.formatDescription); foundFormat = true; if (dims.width == 1000 && dims.height == 6000) { selectedDevice.activeFormat = format; foundFormat = true; break; } } if(foundFormat == false) { NSLog(@"Failed to foundFormat : "); [session commitConfiguration]; return false; } NSError* error = nil; AVCaptureDeviceInput* input = [AVCaptureDeviceInput deviceInputWithDevice:selectedDevice error:&error]; if (error || ![session canAddInput:input]) { NSLog(@"Failed to add video input: %@", error.localizedDescription); [session commitConfiguration]; return false; } [session addInput:input]; AVCaptureVideoDataOutput* output = [[AVCaptureVideoDataOutput alloc] init]; output.alwaysDiscardsLateVideoFrames = YES; output.videoSettings = @{ (NSString*)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange) }; [output setSampleBufferDelegate:delegate queue:queue]; if ([session canAddOutput:output]) { [session addOutput:output]; } [session commitConfiguration]; [selectedDevice unlockForConfiguration]; } else { NSLog(@"Failed to lock device for configuration: %@", error.localizedDescription); } // start~
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410
Jul ’25
Camera become black for few propduction users during photo capture
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) } }```
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259
Jul ’25
storing AVAsset in SwiftData
Hi, I am creating an app that can include videos or images in it's data. While @Attribute(.externalStorage) helps with images, with AVAssets I actually would like access to the URL behind that data. (as it would be stupid to load and then save the data again just to have a URL) One key component is to keep all of this clean enough so that I can use (private) CloudKit syncing with the resulting model. All the best Christoph
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648
Jun ’25
How to toggle usb device
When I use IOKit/usb/IOUSBLib to toggle build-in camera, I got an ERROR:ret IOReturn -536870210 How can I resolve it? Can I use IOUSBLib to disable or hide build-in camera? My environment: Model Name: MacBook Pro ProductVersion: 15.5 Model Identifier: MacBookPro15,2 Processor Name: Quad-Core Intel Core i5 Processor Speed: 2.4 GHz Number of Processors: 1 // 禁用/启用USB设备 bool toggleUSBDevice(uint16_t vendorID, uint16_t productID, bool enable) { std::cout << (enable ? "Enabling" : "Disabling") << " USB device with VID: 0x" << std::hex << vendorID << ", PID: 0x" << productID << std::endl; // 创建匹配字典查找指定VID/PID的USB设备 CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName); if (!matchingDict) { std::cerr << "Failed to create USB device matching dictionary." << std::endl; return false; } // 设置VID/PID匹配条件 CFNumberRef vendorIDRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &vendorID); CFNumberRef productIDRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &productID); CFDictionarySetValue(matchingDict, CFSTR(kUSBVendorID), vendorIDRef); CFDictionarySetValue(matchingDict, CFSTR(kUSBProductID), productIDRef); CFRelease(vendorIDRef); CFRelease(productIDRef); // 获取匹配的设备迭代器 io_iterator_t deviceIterator; if (IOServiceGetMatchingServices(kIOMainPortDefault, matchingDict, &deviceIterator) != KERN_SUCCESS) { std::cerr << "Failed to get USB device iterator." << std::endl; CFRelease(matchingDict); return false; } io_service_t usbDevice; bool result = false; int deviceCount = 0; // 遍历所有匹配的设备 while ((usbDevice = IOIteratorNext(deviceIterator)) != IO_OBJECT_NULL) { deviceCount++; // 获取设备路径 char path[1024]; if (IORegistryEntryGetPath(usbDevice, kIOServicePlane, path) == KERN_SUCCESS) { std::cout << "Found device at path: " << path << std::endl; } // 打开设备 IOCFPlugInInterface** plugInInterface = NULL; IOUSBDeviceInterface** deviceInterface = NULL; SInt32 score; IOReturn ret = IOCreatePlugInInterfaceForService( usbDevice, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID, &plugInInterface, &score); if (ret == kIOReturnSuccess && plugInInterface) { ret = (*plugInInterface)->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID), (LPVOID*)&deviceInterface); (*plugInInterface)->Release(plugInInterface); } if (ret != kIOReturnSuccess) { std::cerr << "Failed to open USB device interface. Error:" << ret << std::endl; IOObjectRelease(usbDevice); continue; } // 禁用/启用设备 if (enable) { // 启用设备 - 重新配置设备 ret = (*deviceInterface)->USBDeviceReEnumerate(deviceInterface, 0); if (ret == kIOReturnSuccess) { std::cout << "Device enabled successfully." << std::endl; result = true; } else { std::cerr << "Failed to enable device. Error: " << ret << std::endl; } } else { // 禁用设备 - 断开设备连接 ret = (*deviceInterface)->USBDeviceClose(deviceInterface); if (ret == kIOReturnSuccess) { std::cout << "Device disabled successfully." << std::endl; result = true; } else { std::cerr << "Failed to disable device. Error: " << ret << std::endl; } } // 关闭设备接口 (*deviceInterface)->Release(deviceInterface); IOObjectRelease(usbDevice); } IOObjectRelease(deviceIterator); if (deviceCount == 0) { std::cerr << "No device found with specified VID/PID." << std::endl; return false; } return result; }
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269
Jun ’25
Playing periodic audio in background using AVFoundation - facing audio session startup failure
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!
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240
Jul ’25
How to disable/hide Audio Controls on lock screen from WkWebView
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
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157
May ’25
Making DataScannerViewController work in the Simulator
Before you post —Camera doesn't work on the Simulator— that's no longer true. I've made a solution that makes the Simulator believe there's an actual hardware device connected, allowing users to stream the macOS camera to the iOS Simulator (see for more info RocketSim's documentation: https://docs.rocketsim.app/features/hzQMSrSga7BGWvxdNVdwYs/simulator-camera-support/58tQ5jvevLNSnyUEA7VgAv) Now, it works for VNDocumentCameraViewController, but when I try opening DataScannerViewController, I directly run into: Failed to start scanning: The operation couldn’t be completed. (VisionKit.DataScannerViewController.ScanningUnavailable error 0.) My question: How does this view controller determine whether scanning is available? Is there a certain capability the available AVCaptureDevice's need to support maybe? Any direction would be helpful for me to make this work for developers, making them build apps faster!
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382
Jul ’25
AVSpeechSynthesisVoices available on device
Hello there! Is there any list of voices that are always available on iOS/iPadOS devices? It seems that AVSpeechSynthesisVoice(identifier: "com.apple.voice.compact.en-US.Samantha") is always available on all devices. I thought that AVSpeechSynthesisVoice(identifier: "com.apple.ttsbundle.siri_Nicky_en-US_compact") and AVSpeechSynthesisVoice(identifier: "com.apple.ttsbundle.siri_Aaron_en-US_compact") were available by default on certain newer devices. Is this true? I also noticed that on the same iPad where I was using those 2 voices (Nicky and Aaron) - when I updated to the iPadOS 26 beta, those voices were no longer available. Any information you can share about which voices should be reliably available on which devices would be extremely helpful for our development. Thanks so much!
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248
Jun ’25
ScaleTimeRange will cause noise in sound
I'm using AVFoundation to make a multi-track editor app, which can insert multiple track and clip, including scale some clip to change the speed of the clip, (also I'm not sure whether AVFoundation the best choice for me) but after making the scale with scaleTimeRange API, there is some short noise sound in play back. Also, sometimes it's fine when play AVMutableCompostion using AVPlayer with AVPlayerItem, but after exporting with AVAssetReader, will catch some short noise sounds in result file.... Not sure why. Here is the example project, which can build and run directly. https://github.com/luckysmg/daily_images/raw/refs/heads/main/TestDemo.zip
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147
Jul ’25
FCPX Workflow Extension: Drag & Drop FCPXML with Titles to Timeline Not Working Despite Following File Promise Guidelines
I'm developing a Final Cut Pro X workflow extension that transcribes audio and creates a text output. I need to allow users to drag this text directly from my extension into FCPX's timeline as titles. Current Implementation: Using NSFilePromiseProvider as per Apple's guidelines for drag and drop Generating valid FCPXML (v1.10) with proper structure: Complete resources section with format and asset references Event and project hierarchy Asset clip with connected title elements Proper timing and duration calculations Supporting multiple pasteboard types: com.apple.finalcutpro.xml.v1-10 com.apple.finalcutpro.xml.v1-9 com.apple.finalcutpro.xml What's Working: Drag operation initiates correctly File promise provider is set up properly FCPXML generation is successful (verified content) All required pasteboard types are registered Proper logging confirms data is being requested and provided Current Pasteboard Types Offered: com.apple.NSFilePromiseItemMetaData com.apple.pasteboard.promised-file-name com.apple.pasteboard.promised-suggested-file-name com.apple.pasteboard.promised-file-content-type Apple files promise pasteboard type com.apple.pasteboard.NSFilePromiseID com.apple.pasteboard.promised-file-url com.apple.finalcutpro.xml.v1-10 com.apple.finalcutpro.xml.v1-9 com.apple.finalcutpro.xml What additional requirements or considerations are needed to make FCPX accept the dragged FCPXML content? Are there specific requirements for workflow extensions regarding drag and drop operations with titles that aren't documented? Any insights, especially from those who have implemented similar functionality in FCPX workflow extensions, would be greatly appreciated. Technical Details: macOS Version: 15.5 (24F74) FCPX Version: 11.1.1 Extension built with SwiftUI and AppKit integration Using NSFilePromiseProvider and NSPasteboardItemDataProvider Full pasteboard type support for FCPXML versions
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230
Jul ’25
AudioUnit may experience silent capture issues on iPadOS 18.4.1 or 18.5.
Among the millions of users of our online product, we have identified through data metrics that the silent audio data capture rate on iPadOS 18.4.1 or 18.5 has increased abnormally. However, we are unable to reproduce the issue. Has anyone encountered a similar issue? The parameters we used are as follows: AudioSession: category:AVAudioSessionCategoryPlayAndRecord mode:AVAudioSessionModeDefault option:77 preferredSampleRate:48000.000000 preferredIOBufferDuration:0.010000 AudioUnit format.mFormatID = kAudioFormatLinearPCM; format.mSampleRate = 48000.0; format.mChannelsPerFrame = 2; format.mBitsPerChannel = 16; format.mFramesPerPacket = 1; format.mBytesPerFrame = format.mChannelsPerFrame * 16 / 8; format.mBytesPerPacket = format.mBytesPerFrame * format.mFramesPerPacket; format.mFormatFlags = kAudioFormatFlagsNativeEndian | kLinearPCMFormatFlagIsPacked | kLinearPCMFormatFlagIsSignedInteger; component.componentType = kAudioUnitType_Output; component.componentSubType = kAudioUnitSubType_RemoteIO; component.componentManufacturer = kAudioUnitManufacturer_Apple; component.componentFlags = 0; component.componentFlagsMask = 0;
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164
Jun ’25
AVKit - PiP with AVSampleBufferDisplayLayer Error
AVPictureInPictureControllerContentSource *contentSource = [[AVPictureInPictureControllerContentSource alloc] initWithSampleBufferDisplayLayer:self.renderView.sampleBufferDisplayLayer playbackDelegate:self]; AVPictureInPictureController *pictureInPictureController = [[AVPictureInPictureController alloc] initWithContentSource:contentSource]; pictureInPictureController.delegate = self; (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController failedToStartPictureInPictureWithError:(NSError *)error { //error NSError * domain: @"PGPegasusErrorDomain" - code: -1003 0x00000002819fe3a0 } when first start the PiP play, I got the error "//error NSError * domain: @"PGPegasusErrorDomain" - code: -1003 0x00000002819fe3a0", why? and second start is Ok.
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217
Jul ’25
Crash in iOS 18 regarding [AVPlayerController _observeValueForKeyPath:oldValue:newValue:]
There are significant crash reports coming from iOS 18 users regarding AVKit framework that starts from this line [AVPlayerController _observeValueForKeyPath:oldValue:newValue:] which seems to be coming from iOS internal SDK. There are 2 kinds of crash we found: UI modification on background thread From the stack trace it seems like when AVPictureInPictureController is being deallocated and its view is being removed from superview somehow the code is being executed in background thread because there is this line there _AssertAutoLayoutOnAllowedThreadsOnly highlighted before the crash. But I’ve checked our code that plays around AVPictureInPictureController, in the locations where we would deallocate the object it will always be called on main thread which are insideviewDidLoad and deinit inside UIViewController class. From the log, it seems like the crash happened when user try to open another content when PIP player is active resulting in the current PIP instance will be replaced with a new one. My suspect is the observation logic inside AVPlayerController could be the hint to this issue, probably something broken over there since this issue happened across our app versions on iOS 18 users only. Unfortunately, I was unable to reproduce this issue yet but one of my colleagues reproduced it once but haven’t been able to do it again since. The reports keep raising each day up to 1.3k events in the last 30 days now. Over release object This one has lower reports than the first one but I decided to include it since it might have relevant information regarding the first crash since the starting stack trace is similar. The crash timing seems to be similar to the first one, where we deallocate existing AVPictureInPictureController and later replace it with a new one and also found only in iOS 18 users which also refers to [AVPlayerController _observeValueForKeyPath:oldValue:newValue:]. I also was unable to reproduce this issue so far. Oh, and both of the issues happened on both iPhone and iPad. We’d appreciate any advice on what we can do to avoid this in the future and probably any hint on why it could happened. I have reported this issue with bug number: FB15620734 I also attached one sample crash report for each of the crashes here. non ui thread access.crash over release.crash
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Activity
Jun ’25
Play MPEG-TS (h264 or HEVC) video stream in iOS App
I'm capturing video stream from GoPro camera (via UDP MPEG-TS packets) but unable to play in iOS app. can someone provide a source code to decode MPEG-TS data to CMSampleBuffer.
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208
Activity
Jul ’25
ShazamKit supported for iOS apps that can run on Mac silicon?
I am having issues deploying my iOS app, that uses ShazamKit, to get working on a Mac with Apple silicon. When uploading the archive to App Store Connect I do get ITMS-90863: Macs with Apple silicon support issue - The app links with libraries that aren’t present in macOS: /usr/lib/swift/libswiftShazamKit.dylib Is ShazamKit not supported for iOS apps that can run on Macs with Apple silicon? Or is there something I should fix in my setup / deployment?
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26
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1.3k
Activity
Jun ’25
WWDC25 Camera & Photos group lab summary (Part 2 of 3)
(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)
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485
Activity
Jul ’25
Mic audio before and after a call is answered
I have an app that records a health provider’s conversation with a patient. I am using Audio Queue Services for this. If a phone call comes in while recording, the doctor wants to be able to ignore the call and continue the conversation without touching the phone. If the doctor answers the call, that’s fine – I will stop the recording. I can detect when the call comes in and ends using CXCallObserver and AVAudioSession.interruptionNotification. Unfortunately, when a call comes in and before it is answered or dismissed, the audio is suppressed. After the call is dismissed, the audio continues to be suppressed. How can I continue to get audio from the mic as long as the user does not answer the phone call?
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84
Activity
May ’25
AVFoundation — MJPEG Custom-Resolution UVC Stream Not Working on macOS
Hello, I'm Soonwon. We’re currently developing a UVC camera device and trying to stream MJPEG video via AVFoundation on macOS. However, we’re running into a problem with custom resolutions. When we try to use AVFoundation on macOS to capture MJPEG video at 1000x6000, the stream is not accepted or simply doesn’t work. Lower resolutions work fine. (Interestingly, using the same device on iPadOS, we can capture the 1000x6000 MJPEG stream successfully by using AVCaptureSessionPresetInputPriority.) Is there any way to receive custom-resolution MJPEG streams (like 1000x6000) from a UVC device using AVFoundation on macOS? Are there specific session presets, entitlements, or known limitations that affect MJPEG handling at custom resolutions on macOS? Does macOS handle MJPEG differently from iPadOS in AVFoundation? Any insight or guidance would be greatly appreciated. Thank you! NSError *error = nil; if ([selectedDevice lockForConfiguration:&error]) { [session beginConfiguration]; session.sessionPreset = AVCaptureSessionPresetHigh; bool foundFormat = false; for (AVCaptureDeviceFormat *format in selectedDevice.formats) { CMVideoDimensions dims = CMVideoFormatDescriptionGetDimensions(format.formatDescription); FourCharCode pixelFormat = CMFormatDescriptionGetMediaSubType(format.formatDescription); foundFormat = true; if (dims.width == 1000 && dims.height == 6000) { selectedDevice.activeFormat = format; foundFormat = true; break; } } if(foundFormat == false) { NSLog(@"Failed to foundFormat : "); [session commitConfiguration]; return false; } NSError* error = nil; AVCaptureDeviceInput* input = [AVCaptureDeviceInput deviceInputWithDevice:selectedDevice error:&error]; if (error || ![session canAddInput:input]) { NSLog(@"Failed to add video input: %@", error.localizedDescription); [session commitConfiguration]; return false; } [session addInput:input]; AVCaptureVideoDataOutput* output = [[AVCaptureVideoDataOutput alloc] init]; output.alwaysDiscardsLateVideoFrames = YES; output.videoSettings = @{ (NSString*)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange) }; [output setSampleBufferDelegate:delegate queue:queue]; if ([session canAddOutput:output]) { [session addOutput:output]; } [session commitConfiguration]; [selectedDevice unlockForConfiguration]; } else { NSLog(@"Failed to lock device for configuration: %@", error.localizedDescription); } // start~
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410
Activity
Jul ’25
How to show animated album artwork in iOS 26?
I have an app that displays artwork via MPMediaItem.artwork, requesting an image with a specific size. How do I get a media item's MPMediaItemAnimatedArtwork, and how to get the preview image and video to display to the user?
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155
Activity
Jun ’25
Camera become black for few propduction users during photo capture
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) } }```
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259
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Jul ’25
storing AVAsset in SwiftData
Hi, I am creating an app that can include videos or images in it's data. While @Attribute(.externalStorage) helps with images, with AVAssets I actually would like access to the URL behind that data. (as it would be stupid to load and then save the data again just to have a URL) One key component is to keep all of this clean enough so that I can use (private) CloudKit syncing with the resulting model. All the best Christoph
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648
Activity
Jun ’25
Tvos 26 beta2 not support dolby atmos Apple tv 4k 3rd
On Apple TV 4K 3rd generation, with tvOS 26 beta 2, when two HomePod 2 are paired to the device, music and movie sources with Dolby Atmos can only be listened to in stereo. dolby atmos not supported
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205
Activity
Jul ’25
How to toggle usb device
When I use IOKit/usb/IOUSBLib to toggle build-in camera, I got an ERROR:ret IOReturn -536870210 How can I resolve it? Can I use IOUSBLib to disable or hide build-in camera? My environment: Model Name: MacBook Pro ProductVersion: 15.5 Model Identifier: MacBookPro15,2 Processor Name: Quad-Core Intel Core i5 Processor Speed: 2.4 GHz Number of Processors: 1 // 禁用/启用USB设备 bool toggleUSBDevice(uint16_t vendorID, uint16_t productID, bool enable) { std::cout << (enable ? "Enabling" : "Disabling") << " USB device with VID: 0x" << std::hex << vendorID << ", PID: 0x" << productID << std::endl; // 创建匹配字典查找指定VID/PID的USB设备 CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName); if (!matchingDict) { std::cerr << "Failed to create USB device matching dictionary." << std::endl; return false; } // 设置VID/PID匹配条件 CFNumberRef vendorIDRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &vendorID); CFNumberRef productIDRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &productID); CFDictionarySetValue(matchingDict, CFSTR(kUSBVendorID), vendorIDRef); CFDictionarySetValue(matchingDict, CFSTR(kUSBProductID), productIDRef); CFRelease(vendorIDRef); CFRelease(productIDRef); // 获取匹配的设备迭代器 io_iterator_t deviceIterator; if (IOServiceGetMatchingServices(kIOMainPortDefault, matchingDict, &deviceIterator) != KERN_SUCCESS) { std::cerr << "Failed to get USB device iterator." << std::endl; CFRelease(matchingDict); return false; } io_service_t usbDevice; bool result = false; int deviceCount = 0; // 遍历所有匹配的设备 while ((usbDevice = IOIteratorNext(deviceIterator)) != IO_OBJECT_NULL) { deviceCount++; // 获取设备路径 char path[1024]; if (IORegistryEntryGetPath(usbDevice, kIOServicePlane, path) == KERN_SUCCESS) { std::cout << "Found device at path: " << path << std::endl; } // 打开设备 IOCFPlugInInterface** plugInInterface = NULL; IOUSBDeviceInterface** deviceInterface = NULL; SInt32 score; IOReturn ret = IOCreatePlugInInterfaceForService( usbDevice, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID, &plugInInterface, &score); if (ret == kIOReturnSuccess && plugInInterface) { ret = (*plugInInterface)->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID), (LPVOID*)&deviceInterface); (*plugInInterface)->Release(plugInInterface); } if (ret != kIOReturnSuccess) { std::cerr << "Failed to open USB device interface. Error:" << ret << std::endl; IOObjectRelease(usbDevice); continue; } // 禁用/启用设备 if (enable) { // 启用设备 - 重新配置设备 ret = (*deviceInterface)->USBDeviceReEnumerate(deviceInterface, 0); if (ret == kIOReturnSuccess) { std::cout << "Device enabled successfully." << std::endl; result = true; } else { std::cerr << "Failed to enable device. Error: " << ret << std::endl; } } else { // 禁用设备 - 断开设备连接 ret = (*deviceInterface)->USBDeviceClose(deviceInterface); if (ret == kIOReturnSuccess) { std::cout << "Device disabled successfully." << std::endl; result = true; } else { std::cerr << "Failed to disable device. Error: " << ret << std::endl; } } // 关闭设备接口 (*deviceInterface)->Release(deviceInterface); IOObjectRelease(usbDevice); } IOObjectRelease(deviceIterator); if (deviceCount == 0) { std::cerr << "No device found with specified VID/PID." << std::endl; return false; } return result; }
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269
Activity
Jun ’25
Playing periodic audio in background using AVFoundation - facing audio session startup failure
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!
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240
Activity
Jul ’25
How to disable/hide Audio Controls on lock screen from WkWebView
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
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2
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157
Activity
May ’25
Making DataScannerViewController work in the Simulator
Before you post —Camera doesn't work on the Simulator— that's no longer true. I've made a solution that makes the Simulator believe there's an actual hardware device connected, allowing users to stream the macOS camera to the iOS Simulator (see for more info RocketSim's documentation: https://docs.rocketsim.app/features/hzQMSrSga7BGWvxdNVdwYs/simulator-camera-support/58tQ5jvevLNSnyUEA7VgAv) Now, it works for VNDocumentCameraViewController, but when I try opening DataScannerViewController, I directly run into: Failed to start scanning: The operation couldn’t be completed. (VisionKit.DataScannerViewController.ScanningUnavailable error 0.) My question: How does this view controller determine whether scanning is available? Is there a certain capability the available AVCaptureDevice's need to support maybe? Any direction would be helpful for me to make this work for developers, making them build apps faster!
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382
Activity
Jul ’25
AVSpeechSynthesisVoices available on device
Hello there! Is there any list of voices that are always available on iOS/iPadOS devices? It seems that AVSpeechSynthesisVoice(identifier: "com.apple.voice.compact.en-US.Samantha") is always available on all devices. I thought that AVSpeechSynthesisVoice(identifier: "com.apple.ttsbundle.siri_Nicky_en-US_compact") and AVSpeechSynthesisVoice(identifier: "com.apple.ttsbundle.siri_Aaron_en-US_compact") were available by default on certain newer devices. Is this true? I also noticed that on the same iPad where I was using those 2 voices (Nicky and Aaron) - when I updated to the iPadOS 26 beta, those voices were no longer available. Any information you can share about which voices should be reliably available on which devices would be extremely helpful for our development. Thanks so much!
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248
Activity
Jun ’25
ScaleTimeRange will cause noise in sound
I'm using AVFoundation to make a multi-track editor app, which can insert multiple track and clip, including scale some clip to change the speed of the clip, (also I'm not sure whether AVFoundation the best choice for me) but after making the scale with scaleTimeRange API, there is some short noise sound in play back. Also, sometimes it's fine when play AVMutableCompostion using AVPlayer with AVPlayerItem, but after exporting with AVAssetReader, will catch some short noise sounds in result file.... Not sure why. Here is the example project, which can build and run directly. https://github.com/luckysmg/daily_images/raw/refs/heads/main/TestDemo.zip
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147
Activity
Jul ’25
SIGABORT with ExtAudioFileWrite and .m4a file
Hi, I am getting into a trap. Please check stack-trace, howto fix this? regards, Joël stack-trace with ExtAudioFileWrite
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1k
Activity
Jun ’25
FCPX Workflow Extension: Drag & Drop FCPXML with Titles to Timeline Not Working Despite Following File Promise Guidelines
I'm developing a Final Cut Pro X workflow extension that transcribes audio and creates a text output. I need to allow users to drag this text directly from my extension into FCPX's timeline as titles. Current Implementation: Using NSFilePromiseProvider as per Apple's guidelines for drag and drop Generating valid FCPXML (v1.10) with proper structure: Complete resources section with format and asset references Event and project hierarchy Asset clip with connected title elements Proper timing and duration calculations Supporting multiple pasteboard types: com.apple.finalcutpro.xml.v1-10 com.apple.finalcutpro.xml.v1-9 com.apple.finalcutpro.xml What's Working: Drag operation initiates correctly File promise provider is set up properly FCPXML generation is successful (verified content) All required pasteboard types are registered Proper logging confirms data is being requested and provided Current Pasteboard Types Offered: com.apple.NSFilePromiseItemMetaData com.apple.pasteboard.promised-file-name com.apple.pasteboard.promised-suggested-file-name com.apple.pasteboard.promised-file-content-type Apple files promise pasteboard type com.apple.pasteboard.NSFilePromiseID com.apple.pasteboard.promised-file-url com.apple.finalcutpro.xml.v1-10 com.apple.finalcutpro.xml.v1-9 com.apple.finalcutpro.xml What additional requirements or considerations are needed to make FCPX accept the dragged FCPXML content? Are there specific requirements for workflow extensions regarding drag and drop operations with titles that aren't documented? Any insights, especially from those who have implemented similar functionality in FCPX workflow extensions, would be greatly appreciated. Technical Details: macOS Version: 15.5 (24F74) FCPX Version: 11.1.1 Extension built with SwiftUI and AppKit integration Using NSFilePromiseProvider and NSPasteboardItemDataProvider Full pasteboard type support for FCPXML versions
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230
Activity
Jul ’25
AudioUnit may experience silent capture issues on iPadOS 18.4.1 or 18.5.
Among the millions of users of our online product, we have identified through data metrics that the silent audio data capture rate on iPadOS 18.4.1 or 18.5 has increased abnormally. However, we are unable to reproduce the issue. Has anyone encountered a similar issue? The parameters we used are as follows: AudioSession: category:AVAudioSessionCategoryPlayAndRecord mode:AVAudioSessionModeDefault option:77 preferredSampleRate:48000.000000 preferredIOBufferDuration:0.010000 AudioUnit format.mFormatID = kAudioFormatLinearPCM; format.mSampleRate = 48000.0; format.mChannelsPerFrame = 2; format.mBitsPerChannel = 16; format.mFramesPerPacket = 1; format.mBytesPerFrame = format.mChannelsPerFrame * 16 / 8; format.mBytesPerPacket = format.mBytesPerFrame * format.mFramesPerPacket; format.mFormatFlags = kAudioFormatFlagsNativeEndian | kLinearPCMFormatFlagIsPacked | kLinearPCMFormatFlagIsSignedInteger; component.componentType = kAudioUnitType_Output; component.componentSubType = kAudioUnitSubType_RemoteIO; component.componentManufacturer = kAudioUnitManufacturer_Apple; component.componentFlags = 0; component.componentFlagsMask = 0;
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164
Activity
Jun ’25
AVKit - PiP with AVSampleBufferDisplayLayer Error
AVPictureInPictureControllerContentSource *contentSource = [[AVPictureInPictureControllerContentSource alloc] initWithSampleBufferDisplayLayer:self.renderView.sampleBufferDisplayLayer playbackDelegate:self]; AVPictureInPictureController *pictureInPictureController = [[AVPictureInPictureController alloc] initWithContentSource:contentSource]; pictureInPictureController.delegate = self; (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController failedToStartPictureInPictureWithError:(NSError *)error { //error NSError * domain: @"PGPegasusErrorDomain" - code: -1003 0x00000002819fe3a0 } when first start the PiP play, I got the error "//error NSError * domain: @"PGPegasusErrorDomain" - code: -1003 0x00000002819fe3a0", why? and second start is Ok.
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217
Activity
Jul ’25