Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.

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Why does CADisplayLink of an external UIScreen drift in time?
I am using Apple's original Lightning Digital AV-adapter (Lightning-to-HDMI dongle) to connect my iPhone to an external display via a HDMI cable. I need to synchronize rendering with the external display's refresh rate, so I create a new CADisplayLink tied to the external display's UIScreen: UIScreen.screens[externalDisplayIdx].displayLink(withTarget:, selector:). The callback is being called regularly, but with increasing delay relative to the CADisplayLink.timestamp, so the next time the callback is called, I have less and less time to draw the next frame (see the snippet below). Assuming 60 FPS, the value of secondsTillDeadline starts at an arbitrary value in the range of approx -0.0001 to 0.0166667, and then it slowly decreases towards zero (and for a brief period it goes into small negative numbers). Once it reaches zero, it flips back to 0.0166667 and continues to decrease again. This cycle repeats indefinitely. Changing the external display's resolution (UIScreen's mode) or the CADisplayLink's preferredFrameRateRange to a lower FPS does not seem to have any effect on the temporal drifting (even the rate of change seem to be the same). When I create a new CADisplayLink for the iPhone's main screen, the value of secondsTillDeadline is stable, it does not drift and it is very close to 0.0166667, as expected. Is this drift caused by the external monitor or by Apple's Lightning-to-HDMI dongle ...or is the problem somewhere else? Can the drifting be stopped? func onDisplayLinkUpdate(displayLink: CADisplayLink) { // Gradually decreases from 0.01667 to -0.0001, then flips back to 0.01667 and continues to decrease let secondsTillDeadline = displayLink.targetTimestamp - CACurrentMediaTime() }
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221
Aug ’25
donate INPlayMediaIntent to systerm, but not show in control center
I donate INPlayMediaIntent to systerm(donate success), but not show in control center My code is as follows let mediaItems = mediaItems.map { $0.inMediaItem } let intent = if #available(iOS 13.0, *) { INPlayMediaIntent(mediaItems: mediaItems, mediaContainer: nil, playShuffled: false, playbackRepeatMode: .none, resumePlayback: true, playbackQueueLocation: .now, playbackSpeed: nil, mediaSearch: nil) } else { INPlayMediaIntent(mediaItems: mediaItems, mediaContainer: nil, playShuffled: false, playbackRepeatMode: .none, resumePlayback: true) } intent.suggestedInvocationPhrase = "播放音乐" let interaction = INInteraction(intent: intent, response: nil) interaction.donate { error in if let error = error { print("Intent 捐赠失败: \(error.localizedDescription)") } else { print("Intent 捐赠成功 ✅") } }
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127
Sep ’25
iOS26中ALAssetsLibrary 编译报错问题
mac os 系统版本:26.0 (25A354) Xcode版本:Version 26.0 (17A324) 项目编译报错 `SwiftExplicitDependencyCompileModuleFromInterface arm64 /Users/zhz/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/AssetsLibrary-HTIJ05N58KN3.swiftmodule /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS26.0.sdk/usr/lib/swift/AssetsLibrary.swiftmodule/arm64e-apple-ios.swiftinterface:10:25: error: 'ALAssetsLibrary' is unavailable in iOS: Use PHPhotoLibrary from the Photos framework instead 8 | public import _StringProcessing 9 | public import _SwiftConcurrencyShims 10 | extension AssetsLibrary.ALAssetsLibrary { | `- error: 'ALAssetsLibrary' is unavailable in iOS: Use PHPhotoLibrary from the Photos framework instead 11 | #if compiler(>=5.3) && $NonescapableTypes 12 | @available(iOS, introduced: 9.0, deprecated: 9.0, obsoleted: 26.0) /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS26.0.sdk/System/Library/Frameworks/AssetsLibrary.framework/Headers/ALAssetsLibrary.h:80:12: note: 'ALAssetsLibrary' was obsoleted in iOS 26.0 78 | 79 | OS_EXPORT AL_DEPRECATED(4, "Use PHPhotoLibrary from the Photos framework instead") 80 | @interface ALAssetsLibrary : NSObject { | `- note: 'ALAssetsLibrary' was obsoleted in iOS 26.0 81 | @package 82 | id _internal; /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS26.0.sdk/usr/lib/swift/AssetsLibrary.swiftmodule/arm64e-apple-ios.swiftinterface:1:1: error: failed to build module 'AssetsLibrary'; this SDK is not supported by the compiler (the SDK is built with 'Apple Swift version 6.2 effective-5.10 (swiftlang-6.2.0.17.14 clang-1700.3.17.1)', while this compiler is 'Apple Swift version 6.2 effective-5.10 (swiftlang-6.2.0.19.9 clang-1700.3.19.1)'). Please select a toolchain which matches the SDK.
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ShazamKit for Android and 16 KB native library alignment
Hello, I'm working on a Flutter app targeting both Android and iOS, where I implemented ShazamKit. In order to achieve that, I first tried with the flutter_shazam_kit package, but since it's not maintained anymore, I forked it here, and tried to update it to meet the Google Play Store requirements, as you can see here: https://github.com/mregnauld/flutter_shazam_kit/tree/fix-16k Unfortunately, after trying everything, my app still doesn't meet the (not so) new 16 KB native library alignment. Also, I'm 100% sure it comes from that because the error message disappears if I remove that package from my app. So after investigating, it seems that the problem comes from the ShazamKit for Android (that you can find here: https://developer.apple.com/download/all/?q=Android%20ShazamKit), and especially the .so files in the .aar file. Is there anything I can do to fix that, or should I wait before the ShazamKit team fix that? I'm totally stuck with that so any help is highly appreciated. Thanks.
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492
Oct ’25
MusicKit in playgrounds not supported?
Has anyone been able to successfully use MusicCatalogSearchRequest in a playgrounds app? I have configured my playground similar to a regular app: app id with automatic music token generation turned on, music access authorized within the app itself, but whenever I query MusicCatalogSearchRequest I get an error thrown with .developerTokenRequestFailed. Considering musickit is restricted in the sim, it would not surprise me if it was the same in playgrounds but it would be super helpful if I could prototype with musickit in playgrounds 4!
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1.3k
Apr ’25
EXIF Makernote no read in Ventura
I have a custom app running on a Mac Studio with Ventura that grabs a snapshot image from a network camera. It then adds some extra information into the EXIF "MakerNote" field. However the metadata cannot be read back out of the image when running Ventrua, it can however be read out of the same image file on a Mac that is not running Ventura. It would appear Apple has removed support for reading MakerNote in Ventura but still supports writing MakerNote in Ventura. This code is about 7 years old and written in ObjC and has worked with no issue until Ventura came along. Calls used CGImageDestinationAddImageFromSource(); // used to write the image to disk with the extra metadata - Works on Ventura CGImageSourceCopyPropertiesAtIndex(); // used to read the meta data from an image - does not return "MakeNote" data Is there a new way to read EXIF "MakeNote" data from image files that was introduced with Ventura?
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921
Nov ’24
Some album artwork from MPMediaItem display as nil
Hey there, I'm trying to display all user's albums using the MediaPlayer library. I'm getting many albums returning nil, but I know artwork exists because they show up in the default Music app. There doesn't seem to be much rhyme or reason for what shows up and what doesn't. All downloaded albums display artwork, but some cloud album artwork displays as well. Here's the code I'm using to debug this. let query = MPMediaQuery.albums() if let albumCollections = query.collections { albums = albumCollections } for album in albums { let artwork = album.representativeItem?.artwork print(artwork, artwork?.image(at: CGSize(width: 100, height: 100))) } Any help would be greatly appreciated. Thanks!
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810
Nov ’24
How to display artwork images from MusicKit with UIKit?
In SwiftUI there is a built-in component for displaying album artworks called Artwork but there is no equivalent for UIKit. My current approach is to use the .url() method to read image's URL and download the image or read it from the disk but the performance is much worse than it was previously with MPMediaItem's artworkImage method. let artworkQueue = DispatchQueue( label: "MusicKit-ArtworkQueue", qos: .default, attributes: .concurrent ) let artworkSemaphore = DispatchSemaphore(value: 5) extension Song { func artworkImage(for size: CGSize, completion: @escaping (UIImage?) -> Void) { artworkQueue.async { artworkSemaphore.wait() defer { artworkSemaphore.signal() } let imageURL = artwork?.url( width: Int(size.width), height: Int(size.height) ) // I hate doing this as it might very well break in the future guard let imageURL, imageURL.scheme == "musicKit" else { return completion(nil) } guard let imageData = try? Data(contentsOf: imageURL), let image = UIImage(data: imageData) else { return completion(nil) } completion(image) } } } I really dislike this approach because it feels hacky but somewhat works. You might ask what's the semaphore for? Well, without it I could notice that MusicKit was choking and after reading too many artworks at once. Can someone from Apple please provide us with an example on how to use MusicKit with UIKit properly? Ideally (IMO) we would have a method defined on Song and other MusicKit structures that returns the image for us, just like MPMediaItem had the .artwork() method. It would make our lives so much easier.
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994
Mar ’25
HDR10 MVHECV can not play on Safari
Hi, just generated a HDR10 MVHEVC file, mediainfo is below: Color range : Limited Color primaries : BT.2020 Transfer characteristics : PQ Matrix coefficients : BT.2020 non-constant Codec configuration box : hvcC+lhvC then generate the segment files with below command: mediafilesegmenter --iso-fragmented -t 4 -f av_1 av_new_1.mov then upload the segment files and prog_index.m3u8 to web server. just find that can not play the HLS stream on Safari... the url is http://ip/vod/prog_index.m3u8 just checked that if i remove the tag Transfer characteristics : PQ when generating the MVHEVC file. above same mediafilesegmenter command and upload the files to web server. the new version of HLS stream is can play on Safari... Is there any way to play HLS PQ video on Safari. thanks.
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780
Feb ’25
Musickit Media player missing output device selection
Hi All, I am working on a DJ playout app (MACOS). The app has a few AVAudioPlayerNode's combined with the ApplicationMusicPlayer from Musickit. I can route the output of the AVaudioPlayer to a hardware device so that the audio files are directed to their own dedicated output on my Mac. The ApplicationMusicPlayer is following the default output and this is pretty annoying. Has anyone found a solution to chain the ApplicationMusicPlayer and get it set to a output device? Thanks Pancras
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546
Feb ’25
Unknown CHHapticError.Code (561015905 == '!pla')
Hello, I'm sporadically getting the unknown CoreHaptics error described in the title, when trying to create a CHHapticPatternPlayer from an .ahap file — this does not occur in a repeatable manner, unfortunately... This occurs in a SpriteKit game, running on both iOS 17 and 18. Anyone know what the error means, since it's apparently undocumented? Note that the haptics engine is started right before creating the pattern, and the start request doesn't appear to fail... Thanks, D.
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479
Jan ’25
How Does iPhone 15+ (USB-C) Support UVC Devices? Is MFi Certification Required?
In the past, when using Lightning, many external devices had to go through MFi certification. However, since the iPhone 15 switched from Lightning to USB-C, is MFi certification still required? Our company has developed several UVC devices, and we have confirmed that iPads can read frames from external cameras through the external device type in AVFoundation. However, this is not supported on iPhones. We are currently exploring feasible ways to enable UVC device support on iPhones. Is MFi certification the only option? If so, is the MFi certification process for USB-C the same as it was for Lightning? Does it still require purchasing an MFi chip and manufacturing specially designed USB-C cables?
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197
Mar ’25
401 Authorization error for Music Feed API
I've established proper authorization for general music api calls, but when I use that same authorization to retrieve metadata for the latest music feeds (see https://developer.apple.com/documentation/applemusicfeed/requesting-a-feed-export), I get a 401 Unauthorized error. As per the documentation, I'm simply issuing a GET against https://api.media.apple.com/v1/feed/album/latest. Are there different entitlements needed for the Music Feed API?
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78
May ’25
BackgroundAssets `url(for:` throws error for locally available asset
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
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173
Aug ’25
MPMusicPlayerController.applicationMusicPlayer.currentPlaybackRate no longer working in iOS 26.0 (Tahoe)?
I'm wondering if someone happened issues with currentPlaybackRate in released version of iOS 26.0? There is no issue happened in case of iOS 18.5. When I changed currentPlaybackRate on iOS 26.0, it seems to unexpectedly change currentPlaybackRate to be 0 or 1.0 forcibly no matter DRM or non-DRM contents. And also, playing music will be abnormal behavior and unstable with noise if currentPlaybackRate is not 1.0. And changes stop state and play state frequently.
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