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

I have a USB audio interface that is causing kernel traps and the audio output to "skip" or dropout every few seconds. This behavior occurs with a completely fresh install of Catalina as well as Big Sur with the stock Music app on a 2019 MacBook Pro 16 (full specs below). The Console logs show coreaudiod got an error from a kernel trap, a "USB Sound assertion" in AppleUSBAudio/AppleUSBAudio-401.4/KEXT/AppleUSBAudioDevice.cpp at line 6644, and the Music app "skipping cycle due to overload." I've added a short snippet from Console logs around the time of the audio skip/drop out. The more complete logs are at this gist: https://gist.github.com/djflux/08d9007e2146884e6df1741770de5105 I've also opened a Feedback Assistant ticket (FB9037528): https://feedbackassistant.apple.com/feedback/9037528 Does anyone know what could be causing this issue? Thanks for any help. Cheers, Flux aka Andy. Hardware Overview:  Model Name: MacBook Pro  Model Identifier: MacBookPro16,1  Processor Name: 8-Core Intel Core i9  Processor Speed: 2.4 GHz  Number of Processors: 1  Total Number of Cores: 8  L2 Cache (per Core): 256 KB  L3 Cache: 16 MB  Hyper-Threading Technology: Enabled  Memory: 64 GB  System Firmware Version: 1554.80.3.0.0 (iBridge: 18.16.14347.0.0,0) System Software Overview: System Version: macOS 11.2.3 (20D91)  Kernel Version: Darwin 20.3.0  Boot Volume: Macintosh HD  Boot Mode: Normal  Computer Name: mycomputername  User Name: myusername  Secure Virtual Memory: Enabled  System Integrity Protection: Enabled USB interface: Denon DJ DS1 Snippet of Console logs error 21:07:04.848721-0500 coreaudiod HALS_IOA1Engine::EndWriting: got an error from the kernel trap, Error: 0xE00002D7 default 21:07:04.848855-0500 Music HALC_ProxyIOContext::IOWorkLoop: skipping cycle due to overload default 21:07:04.857903-0500 kernel USB Sound assertion (Resetting engine due to error returned in Read Handler) in /AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleUSBAudio/AppleUSBAudio-401.4/KEXT/AppleUSBAudioDevice.cpp at line 6644 ... default 21:07:05.102746-0500 coreaudiod Audio IO Overload inputs: 'private' outputs: 'private' cause: 'Unknown' prewarming: no recovering: no default 21:07:05.102926-0500 coreaudiod   CAReportingClient.mm:508  message {   HostApplicationDisplayID = "com.apple.Music";   cause = Unknown;   deadline = 2615019;   "input_device_source_list" = Unknown;   "input_device_transport_list" = USB;   "input_device_uid_list" = "AppleUSBAudioEngine:Denon DJ:DS1:000:1,2";   "io_buffer_size" = 512;   "io_cycle" = 1;   "is_prewarming" = 0;   "is_recovering" = 0;   "issue_type" = overload;   lateness = "-535";   "output_device_source_list" = Unknown;   "output_device_transport_list" = USB;   "output_device_uid_list" = "AppleUSBAudioEngine:Denon DJ:DS1:000:1,2"; }: (null)

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?

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

I am using the sample app from: https://developer.apple.com/videos/play/wwdc2025/277/?time=763 I installed this on an Iphone 15 Pro with iOS 26 beta 1. I was able to get good transcription with it. The app did crash sometimes when transcribing and I was going to post here with the details. I then installed iOS beta 2 and uninstalled the sample app. Now every time I try to run the sample app on the 15 Pro I get this message: SpeechAnalyzer: Input loop ending with error: Error Domain=SFSpeechErrorDomain Code=10 "Cannot use modules with unallocated locales [en_US (fixed en_US)]" UserInfo={NSLocalizedDescription=Cannot use modules with unallocated locales [en_US (fixed en_US)]} I can't continue our our work towards using SpeechAnalyzer now with this error. I have set breakpoints on all the catch handlers and it doesn't catch this error. My phone region is "United States"

I'm playing library items (MPMediaItem) and apple music tracks (Track) in MPMusicPlayerApplicationController.applicationQueuePlayer, but I can't use the actual Queue functionality because I can't figure out how to get both media types into the same queue. If there's a way to get both types in a single queue, that would solve my problem, but I've given up on that one. Because I can't use a queue, I have to be able to detect when a song ends so that I can put the next song in the queue and play it. The only way I can figure out to detect when a song ends is by watching the playBackState, and I've actually got that pretty much working, but it's really ugly, because you get playBackState of paused when a song ends, and when a bluetooth speaker disconnects, etc. The only answer I've been able to find on the internet is to watch the MPMusicPlayerControllerNowPlayingItemDidChange, and when that fires, and the nowPlayingItem is NIL, a song ends.. but that's not the case. When a song ends, the nowPlayingItem remains the same. There's got to be an answer to this problem, right?

I'm very excited about the new MusicLibrary API, but after a couple of days of playing around with it, I have to say that I find the implementation of filtering MusicLibraryRequests a little confusing. MPMediaQuery has a fairly extensive list of predicates that can be applied, including string and persistentID comparisons for artist, album artist genre, and more. It also lets you filter on an item’s title. MusicLibraryRequests let you filter on the item’s ID, or on its MusicKit Artist and Genre relationships. To me, this seems like it adds an extra step.  With an MPMediaQuery, if I wanted to fetch every album by a given artist, I’d apply an MPMediaPropertyPredicate looking at MPMediaItemPropertyAlbumArtist and compare the string. It was also easy to change the MPMediaPredicateComparison to .contains to match more widely. If I wanted to surface albums by “Aesop Rock” or “Aesop Rock & Blockhead,” I could use that. In the MusicLibraryRequest implementation, it looks like I need to perform a MusicLibraryRequest<Artist> first in order to get the Artist objects. There’s no filter for the name property, so if I don’t have their IDs, I’ve got to use filter(text:). From there, I can take the results of that request and apply them to my MusicLibraryRequest<Album> using the filter(matching:memberOf) function.  I could use filter(text:) on the MusicLibraryRequest<Album>, but that filters across multiple properties (title and artistName?) and is less precise than defining the actual property I want to match against. I think my ideal version of the MusicLibraryRequest API would offer something like filter(matching:equalTo:) or filter(matching:contains:) that worked off of KeyPaths rather than relationships. That seems more intuitive to me. I’m not saying we need every property from every filterable MPMediaItemProperty key, but I’d love to be able to do it on title, artistName, and other common metadata. That might look something like: filter(matching: \.title, contains: “Abbey Road”) filter(matching: \.artistName, equalTo: “Between The Buried And Me”) I noticed that filter(text:) is case insensitive, which is awesome, and something I’ve wanted for a long time in MPMediaPropertyPredicate. As a bonus, it would be great if a KeyPath based filter API supported a case sensitivity flag. This is less of a problem when dealing with Apple Music catalog content, but users’ libraries are a harsh environment, and you might have an artist “Between The Buried And Me” and one called “Between the Buried and Me.” It would be great to get albums from both with something like: filter(matching: \.artistName, equalTo: “Between The Buried And Me”, caseSensitive: false)  I've submitted the above as FB10185685. I also submitted another feedback this morning regarding filter(text:) and repeating text as FB10184823. My last wishlist item for this API (for the time being!) is exposing the MPMediaItemPropertyAlbumPersistentID as an available filter attribute. I know, I know… hear me out. If you take a look at the other thread I made today, you’ll see that due to missing metadata in MusicKit, I still have some use cases where I need to be able to reference an MPMediaItem and might need to fetch its containing MPMediaItemCollection to get at other tracks on the album. It would be nice to seamlessly be able to fetch the MPMediaItemCollection or the library Album using a shared identifier, especially when it comes to being able to play the album in MusicKit’s player rather than Media Player’s.  I've submitted that list bit as FB10185789 Thanks for bearing with my walls of text today. Keep up the great work!

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

We are getting reports from customers that they are not able to play videos in our app after updating their phones to iOS18.3.1. (Further checking indicates that it happens on all iOS18 versions. It suddenly started occurring from February 18th, 2025) When checking logs we see that playback is failing due to CoreMediaErrorDomain error -42709. This is an undocumented error code and hence we do not know the cause of the playback issue. Does anyone know what this error code means and how the app should handle it? Reported as FB16638501.

So I've spent the last five years optimizing my video AI system so that it runs with less than 5% CPU while processing a 30fps video feed on a Macbook Pro M2, and everything is great, until Sonoma comes out, and I find myself consuming 40% CPU for the exact same workload. So I fire up Instruments, and the "heaviest stack trace" (see screenshot) turns out to be Espresso doing some completely unasked-for and absolutely useless processing on my video frames. I turn off Reactions, but nothing helps - the CPU consumptions stays at 40%. "Reactions" is nothing but a useless toy to please some WWDC keynote fanboys, I don't want it anywhere near my app or my users, and I especially do not want to take the blame for it pissing away the user's CPU cycles and battery. Now, how do I make it go away, for ever? Best regards Jacob

Our multimedia application Boinx FotoMagico displays media files of various kinds with a Metal rendering engine. At the moment we still use .bgra8Unorm pixel format and sRGB color space and only render in SDR, which is increasingly a problem, as much of the video content is HDR nowadays (e.g. videos shot on an iPhone). For that reason we would like to switch to EDR rendering with .rgba16Float pixel format and extendedLinearDisplayP3 color space. We have already worked out how to do this for HDR image files, but still have a technical problem when rendering HDR video files. We are using AVFoundation to get the video frames as CVPixelBuffers and convert them to MTLTexture using a CVMetalTextureCache. MTLTextures are then further processed in various compute shaders before being rendered to screen. However the pixel values in the texture are not what we expected. Video frames appear too bright/overexposed. In WWDC21 session "Explore HDR rendering with EDR" Ken Greenebaum mentioned: “AVFoundation does not presently decode HDR formats, such as HDR10, to EDR. Consequently, these need to be adapted for use with EDR rendering. This conversion is straightforward and involves two steps. First, converting to linear light by applying the inverse transfer function. And second, dividing by the medium's reference white.” https://developer.apple.com/videos/play/wwdc2021/10161?time=1498 However, the session does not explain, how to get or calculate the correct value for "reference white". We could not find any relevant info on the web. This is why we need DTS assistance. We need the code that calculates the correct value for reference white for any kind of video, whether it is SDR or HDR, and regardless of codec and encoding. I assume that Ken Greenebaum is the best Apple engineer to ask in this case, because he recorded most of the EDR related WWDC sessions in recent years? We have written a small test app that renders a short sample video (HLG encoding). The window contains two views. The upper view uses an AVPlayerLayer and renders the video natively just like QuickTime Player. The video content looks correct here. BTW, the window background is SDR white, so that bright EDR pixels can be clearly identified, e.g. the clouds just above the mountains in the upper left corner of the sample video. You may need to lower display brightness a bit if these clouds do not appear brighter than the white window background. The bottom view uses a CAMetalLayer and low-level Metal rendering. The CVPixelBuffers we receive from AVFoundation still need to be scaled down so that SDR reference white reaches pixel value 1.0. Entering a value of 9.0 to 10.0 for reference white in the text field makes it look about right on my Studio Display. But that is just experimental for this sample video file. We need code to calculate the correct value for reference white for any kind of video file! We have a couple of questions: SDR videos should probably use 1.0 as reference white, as their encoded pixel values can already be used as is? Is this assumption correct? Different video encoding of HDR video (HLG, PQ, etc) will probably lead to different values for reference white? Is the value for reference white constant throughout a video, or can it vary over time, either scene by scene, or even frame by frame? If it can vary, does the CVPixelBuffer of the current video frame contain all the necessary metadata to calculate the correct value? Does the NSScreen.maximumExtendedDynamicRangeColorComponentValue also influence the reference white value? The attached sample project is structured in a way that the only piece of code that needs to be modified is the ViewController.sdrReferenceWhiteValue() function. Please read the comments and the #warning in this function. This is where the code for calculating the reference white value should be inserted. Here is the download link for the sample project: https://www.dropbox.com/scl/fi/4w5gmftav5xhbixu9u6pb/HDRMetalTest.zip?rlkey=n8cm02soux3rx03vplgo6h1lm&dl=0

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

Hello, First, some version and software details: Software: iOS 18.1 Hardware: iPhone 14 Pro Max and later Xcode: 16.0 Summary: AVAssetReader is not concatenating a video at the beginning of the output video. The output video should contain a scene of me introducing the content, followed by a blue screen with AVSpeechSynthesizer reading out a text that I pasted above the "Generate Video" button. Details: Now, let's talk about the app. Basically, I’m developing an app that generates a video with the following features: My app will create an output video that is split into an opening scene followed by a fully blue screen. The opening scene will be taken from a video I choose from my gallery. I will read the opening video using AVAssetReader as usual. After the opening scene, I will use the content of a text read by AVSpeechSynthesizer.write(). After the opening scene, the synthesized audio will start playing while the blue screen is displayed. All of this is already defined in the attached project. Each project file has a comment at the beginning introducing its content. How to test: Write something in the field above the "Generate Video" button. For example, type "Hello, world!" Then, press the "Library" button and select a video from the gallery, about 30 seconds long. That’s it. Press the "Generate Video" button. The result I’ve experienced is a crash or failure to generate the video. Practical example of what I want to achieve: Suppose I record a 30-second video where I say, "I’m going to tell you the story of Snow White." Then, I paste the "Snow White" story into the field above the "Generate Video" button. The output video should contain me saying, "I’m going to tell you the story of Snow White." After that, the AVSpeechSynthesizer will read the story I pasted, while displaying a blue screen. I look forward to a solution. Thank you very much! convertToCMSampleBuffer.swift convertToPixelBuffer.swift createInputs.swift createVideo.swift test.swift saveVideo.swift TestApp.swift editingVideo.swift sampleReaderProvider.swift misc.swift sampleProvider.swift

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

Hi all, I'm working on an audio visualizer app that plays files from the user's music library utilizing MediaPlayer and AVAudioEngine. I'm working on getting the music library functionality working before the visualizer aspect. After setting up the engine for file playback, my app inexplicably crashes with an EXC_BREAKPOINT with code = 1. Usually this means I'm unwrapping a nil value, but I think I'm handling the optionals correctly with guard statements. I'm not able to pinpoint where it's crashing. I think it's either in the play function or the setupAudioEngine function. I removed the processAudioBuffer function and my code still crashes the same way, so it's not that. The device that I'm testing this on is running iOS 26 beta 3, although my app is designed for iOS 18 and above. After commenting out code, it seems that the app crashes at the scheduleFile call in the play function, but I'm not fully sure. Here is the setupAudioEngine function: private func setupAudioEngine() { do { try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default) try AVAudioSession.sharedInstance().setActive(true) } catch { print("Audio session error: \(error)") } engine.attach(playerNode) engine.attach(analyzer) engine.connect(playerNode, to: analyzer, format: nil) engine.connect(analyzer, to: engine.mainMixerNode, format: nil) analyzer.installTap(onBus: 0, bufferSize: 1024, format: nil) { [weak self] buffer, _ in self?.processAudioBuffer(buffer) } } Here is the play function: func play(_ mediaItem: MPMediaItem) { guard let assetURL = mediaItem.assetURL else { print("No asset URL for media item") return } stop() do { audioFile = try AVAudioFile(forReading: assetURL) guard let audioFile else { print("Failed to create audio file") return } duration = Double(audioFile.length) / audioFile.fileFormat.sampleRate if !engine.isRunning { try engine.start() } playerNode.scheduleFile(audioFile, at: nil) playerNode.play() DispatchQueue.main.async { [weak self] in self?.isPlaying = true self?.startDisplayLink() } } catch { print("Error playing audio: \(error)") DispatchQueue.main.async { [weak self] in self?.isPlaying = false self?.stopDisplayLink() } } } Here is a link to my test project if you want to try it out for yourself: https://github.com/aabagdi/VisualMan-example Thanks!

Hi everyone, I’ve encountered an issue with the showsPlaybackControls property in AVPlayerViewController after updating to iOS 18. Even though it’s set to true, the native playback controls (play, pause, etc.) are no longer appearing as they used to in previous iOS versions. This behavior was consistent and worked perfectly prior to iOS 18. Additionally, I’m seeing the same problem when using the VideoPlayer in SwiftUI. The native controls that should appear by default seem to have vanished after the update. Has anyone else experienced this? Is there any workaround or additional configuration required to restore the native controls? Any help or insights would be appreciated. Thanks! struct CustomPlayerView: UIViewControllerRepresentable { let player: AVPlayer func updateUIViewController(_ playerController: AVPlayerViewController, context: Context) { playerController.player = player playerController.showsPlaybackControls = true player.play() } func makeUIViewController(context: Context) -> AVPlayerViewController { return AVPlayerViewController() } }

I'm developing an iOS app using DockKit to control a motorized stand. I've noticed that as the zoom factor of the AVCaptureDevice increases, the stand's movement becomes increasingly erratic up and down, almost like a pendulum motion. I'm not sure why this is happening or how to fix it. Here's a simplified version of my tracking logic: func trackObject(_ boundingBox: CGRect, _ dockAccessory: DockAccessory) async throws { guard let device = AVCaptureDevice.default(for: .video), let input = try? AVCaptureDeviceInput(device: device) else { fatalError("Camera not available") } let currentZoomFactor = device.videoZoomFactor let dimensions = device.activeFormat.formatDescription.dimensions let referenceDimensions = CGSize(width: CGFloat(dimensions.width), height: CGFloat(dimensions.height)) let intrinsics = calculateIntrinsics(for: device, currentZoom: Double(currentZoomFactor)) let deviceOrientation = UIDevice.current.orientation let cameraOrientation: DockAccessory.CameraOrientation = { switch deviceOrientation { case .landscapeLeft: return .landscapeLeft case .landscapeRight: return .landscapeRight case .portrait: return .portrait case .portraitUpsideDown: return .portraitUpsideDown default: return .unknown } }() let cameraInfo = DockAccessory.CameraInformation( captureDevice: input.device.deviceType, cameraPosition: input.device.position, orientation: cameraOrientation, cameraIntrinsics: useIntrinsics ? intrinsics : nil, referenceDimensions: referenceDimensions ) let observation = DockAccessory.Observation( identifier: 0, type: .object, rect: boundingBox ) let observations = [observation] try await dockAccessory.track(observations, cameraInformation: cameraInfo) } func calculateIntrinsics(for device: AVCaptureDevice, currentZoom: Double) -> matrix_float3x3 { let dimensions = CMVideoFormatDescriptionGetDimensions(device.activeFormat.formatDescription) let width = Float(dimensions.width) let height = Float(dimensions.height) let diagonalPixels = sqrt(width * width + height * height) let estimatedFocalLength = diagonalPixels * 0.8 let fx = Float(estimatedFocalLength) * Float(currentZoom) let fy = fx let cx = width / 2.0 let cy = height / 2.0 return matrix_float3x3( SIMD3<Float>(fx, 0, cx), SIMD3<Float>(0, fy, cy), SIMD3<Float>(0, 0, 1) ) } I'm calling this function regularly (10-30 times per second) with updated bounding box information. The erratic movement seems to worsen as the zoom factor increases. Questions: Why might increasing the zoom factor cause this erratic movement? I'm currently calculating camera intrinsics based on the current zoom factor. Is this approach correct, or should I be doing something differently? Are there any other factors I should consider when using DockKit with a variable zoom? Could the frequency of calls to trackRider (10-30 times per second) be contributing to the erratic movement? If so, what would be an optimal frequency? Any insights or suggestions would be greatly appreciated. Thanks!

Recently I've been trying to play some AV1-encoded streams on my iPhone 15 Pro Max. First, I check for hardware support: VTIsHardwareDecodeSupported(kCMVideoCodecType_AV1); // YES Then I need to create a CMFormatDescription in order to pass it into a VTDecompressionSession. I've tried the following: { mediaType:'vide' mediaSubType:'av01' mediaSpecific: { codecType: 'av01' dimensions: 394 x 852 } extensions: {{ CVFieldCount = 1; CVImageBufferChromaLocationBottomField = Left; CVImageBufferChromaLocationTopField = Left; CVPixelAspectRatio = { HorizontalSpacing = 1; VerticalSpacing = 1; }; FullRangeVideo = 0; }} } but VTDecompressionSessionCreate gives me error -8971 (codecExtensionNotFoundErr, I assume). So it has something to do with the extensions dictionary? I can't find anywhere which set of extensions is necessary for it to work 😿. VideoToolbox has convenient functions for creating descriptions of AVC and HEVC streams (CMVideoFormatDescriptionCreateFromH264ParameterSets and CMVideoFormatDescriptionCreateFromHEVCParameterSets), but not for AV1. As of today I am using XCode 15.0 with iOS 17.0.0 SDK.

Hi guys, How to achieve the following feature on macOS when a USB device (Camera/Mic/Speaker) is connected: When a third-party video conferencing app is not in a meeting, ensure the app defaults to using the USB device (Camera/Mic/Speaker). When a third-party conferencing app is in a meeting, ensure the app automatically switches to the USB device (Camera/Mic/Speaker). I want to make use of IOKit extension to hidden or ignore build-in camera to realize the requirement. however the extension can't be loaded for Invalid permissions in MacOS 15.4.1, buildVersion:24E263. I also tried to run in in MacOS 14.4.1, which can be loaded but can't auto load when restart laptop as KDK version not match. Could you please give me some suggestion? Is it possible hidden build-in camera in MacOS M-series chip? Is there any other method to realize the feature. Thanks a lot.

Hi, I would like to use macro-mode for the custom camera using AVCaptureDevice in my project. This feature might help to automatically adjust and switch between lenses to get a close up clear image. It looks like this feature is not available and there are no open apis to achieve macro mode from Apple. Is there a way to get this functionality in the custom camera without losing the image quality. Please let me know if this is possible. Thanks you, Adil Thamarasseri