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How to get iCloud item(photo/video) size?
How I can get iCloud photo file size? Could I use private API like this in prod? Does anyone know another way? (without downloading the file to the device) func getFileSize(asset: PHAsset) -> Int64? { let resources = PHAssetResource.assetResources(for: asset) let resource = resources.first let size = resource?.value(forKey: "fileSize") as? Int64 return size }
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139
Mar ’26
Implementing PHBackgroundResourceUploadExtension
Hi, I am trying to implement a PHBackgroundResourceUploadExtension to upload backup media files to an external cloud service based on these docs: https://aninterestingwebsite.com/documentation/PhotoKit/uploading-asset-resources-in-the-background#Acknowledge-completed-jobs Creating jobs and actual uploading is working as expected, but the problem I have is in the acknowledgeCompletedJobs() function. When trying to access a job's resource, the resource is nil and thus has empty assetLocalIdentifier and originalFilename. Did anybody successfully implement this extension or knows, why this would happen? Because the resource of an acknowledgable job is empty, I can not match it back to my processed assets.
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Mar ’26
Implementing PHBackgroundResourceUploadExtension
Hi, I am trying to implement a PHBackgroundResourceUploadExtension to upload backup media files to an external cloud service based on these docs: https://aninterestingwebsite.com/documentation/PhotoKit/uploading-asset-resources-in-the-background#Acknowledge-completed-jobs Creating jobs and actual uploading is working as expected, but the problem I have is in the acknowledgeCompletedJobs() function. When in this function, I am trying to access a job's resource. The resource is nil and thus has empty assetLocalIdentifier and originalFilename. Did anybody successfully implement this extension or knows, why this would happen? Because the resource of an acknowledgable job is empty, I can not match it back to my processed assets.
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Mar ’26
Unity iOS (Metal) → WebRTC (Unity WebRTC) video stream to remote Unity client: PeerConnection connects but receiver renders black frames
Hello! My name is Mason Prather. I'm a graduate student at Kennesaw State University and a Research Engineer working in XR environments through my Graduate Research Assistant role. I’m currently building a research prototype that connects a mobile companion application to a VR headset. The mobile application is built in Unity and deployed on iOS, and it streams video frames to a remote Unity client using WebRTC. Environment Device: iPhone 15 OS: iOS 26.3 (tested on physical device, not Simulator) Engine: Unity 2022.3.57f1 Graphics API: Metal Streaming Technology: WebRTC (Unity WebRTC package) Architecture: Mobile Unity app streaming video frames to a remote Unity client Receiver Device: Meta Quest Pro headset (Unity application) Networking: LAN (UDP discovery + TCP signaling) Video Source: Unity RenderTexture Goal The goal of the system is to allow a VR user to view media stored on their phone inside a VR environment. The iOS app: renders or captures media content converts frames into a WebRTC video track streams the video to the headset Current Status Connection setup works correctly. Observed behavior: Signaling connection successful ICE candidate exchange successful PeerConnection state becomes Connected Video track created successfully However, the receiving application displays black frames. iOS App Details The video source originates from a Unity RenderTexture. Inside the phone application: RenderTexture displays correctly Frames appear correct locally But the receiving peer does not display the frames. Relevant Components Unity WebRTC package iOS Metal rendering pipeline Custom TCP signaling LAN discovery via UDP Expected Behavior Rendered frames should transmit via WebRTC and appear on the remote device. Actual Behavior The remote video track is active, but the rendered frames appear black on the receiving client. Questions Are there known issues involving Unity WebRTC + iOS Metal texture capture? Are there specific pixel format requirements when streaming textures from Unity on iOS? Could the issue relate to texture readback limitations or GPU synchronization? I am more than happy to provide screenshots and console logs upon request. If anyone has experience streaming Unity video frames via WebRTC on iOS, I would greatly appreciate any guidance.
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Mar ’26
AVAssetDownloadConfiguration: How many video variants are actually downloaded when multiple variants exist in the HLS master playlist?
Hi, I’m trying to better understand how AVAssetDownloadConfiguration selects video variants when downloading HLS content for offline playback. Suppose I have an HLS master playlist (.m3u8) that contains several video variants defined with #EXT-X-STREAM-INF. For example, the master playlist may contain multiple video streams like this: Same resolution, different BANDWIDTH Or different resolutions (for example 720p, 1080p, etc.) My question is: How many video variants are actually downloaded when using AVAssetDownloadConfiguration without specifying any variantQualifiers? In other words: If the master playlist contains multiple video variants, will the download task fetch only one variant, or multiple variants? Does the behavior differ depending on whether the variants differ only by BANDWIDTH or also by RESOLUTION? What I observed in testing In my tests, I always end up with only one video variant downloaded, specifically the one with the highest BANDWIDTH parameter. In the m3u8 files I tested, all video variants had identical parameters (resolution, codec, frame rate, etc.) and differed only by the BANDWIDTH attribute in the master playlist. However, when inspecting the downloaded .movpkg, I noticed something interesting in boot.xml. It lists two video streams: one with complete="true" (the one with highest bandwidth) another with complete="no" (the one with lowest bandwidth) I actually had 3 video streams listed in m3u8, but the one with middle bandwidth wasn't listed in boot.xml file at all. There are also additional streams for audio and subtitles in boot.xml file. This made me wonder whether the system initially attempts to download another video variant (possibly a lower bitrate one), but then switches to the highest-quality variant and only completes that one. Additional question about variantQualifiers If I provide a predicate such as: NSPredicate(format: "peakBitRate > 0") which should theoretically match all variants, will the download task attempt to download all matching video variants, or will it still select only one? Summary So the main questions are: Without variantQualifiers, does AVAssetDownloadConfiguration always download a single video variant, and if so, how is it chosen? Does the behavior differ if variants have different resolutions vs only different bitrates? When a predicate matches multiple variants, can multiple video variants actually be downloaded in a single .movpkg? Why might boot.xml list multiple video streams when only one appears to be fully downloaded? Any clarification on the intended behavior would be greatly appreciated. Thanks!
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Mar ’26
Swift Array Out of Bounds Crash in VTFrameProcessor when using VTLowLatencyFrameInterpolationParameters
Hi everyone, Our team is encountering a reproducible crash when using VTLowLatencyFrameInterpolation on iOS 26.3 while processing a live LL-HLS input stream. 🤖 Environment Device: iPhone 16 OS: iOS 26.3 Xcode: Xcode 26.3 Framework: VideoToolbox 💥 Crash Details The application crashes with the following fatal error: Fatal error: Swift/ContiguousArrayBuffer.swift:184: Array index out of range The stack trace highlights the following: VTLowLatencyFrameInterpolationImplementation processWithParameters:frameOutputHandler: Called from VTFrameProcessor.process(parameters:) Here is the simplified implementation block where the crash occurs. (Note: PrismSampleBuffer and PrismLLFIError are our internal custom wrapper types). // Create `VTFrameProcessorFrame` for the source (previous) frame. let sourcePTS = sourceSampleBuffer.presentationTimeStamp var sourceFrame: VTFrameProcessorFrame? if let pixelBuffer = sourceSampleBuffer.imageBuffer { sourceFrame = VTFrameProcessorFrame(buffer: pixelBuffer, presentationTimeStamp: sourcePTS) } // Validate the source VTFrameProcessorFrame. guard let sourceFrame else { throw PrismLLFIError.missingImageBuffer } // Create `VTFrameProcessorFrame` for the next frame. let nextPTS = nextSampleBuffer.presentationTimeStamp var nextFrame: VTFrameProcessorFrame? if let pixelBuffer = nextSampleBuffer.imageBuffer { nextFrame = VTFrameProcessorFrame(buffer: pixelBuffer, presentationTimeStamp: nextPTS) } // Validate the next VTFrameProcessorFrame. guard let nextFrame else { throw PrismLLFIError.missingImageBuffer } // Calculate interpolation intervals and allocate destination frame buffers. let intervals = interpolationIntervals() let destinationFrames = try framesBetween(firstPTS: sourcePTS, lastPTS: nextPTS, interpolationIntervals: intervals) let interpolationPhase: [Float] = intervals.map { Float($0) } // Create VTLowLatencyFrameInterpolationParameters. // This sets up the configuration required for temporal frame interpolation between the previous and current source frames. guard let parameters = VTLowLatencyFrameInterpolationParameters( sourceFrame: nextFrame, previousFrame: sourceFrame, interpolationPhase: interpolationPhase, destinationFrames: destinationFrames ) else { throw PrismLLFIError.failedToCreateParameters } try await send(sourceSampleBuffer) // Process the frames. // Using progressive callback here to get the next processed frame as soon as it's ready, // preventing the system from waiting for the entire batch to finish. for try await readOnlyFrame in self.frameProcessor.process(parameters: parameters) { // Create an interpolated sample buffer based on the output frame. let newSampleBuffer: PrismSampleBuffer = try readOnlyFrame.frame.withUnsafeBuffer { pixelBuffer in try PrismLowLatencyFrameInterpolation.createSampleBuffer(from: pixelBuffer, readOnlyFrame.timeStamp) } // Pass the newly generated frame to the output stream. try await send(newSampleBuffer) } 🙋 Questions Are there any known limitations or bugs regarding VTLowLatencyFrameInterpolation when handling live 60fps streams? Are there any undocumented constraints we should be aware of regarding source/previous frame timing, pixel buffer attributes, or how destinationFrames and interpolationPhase arrays must be allocated? Is a "warm-up" sequence recommended after startSession() before making the first process(parameters:) call?
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Mar ’26
Final Cut Pro not loading my plugin
I have exhausted standard debugging approaches and need guidance on Final Cut Pro's AU plugin loading behavior. PLUGIN OVERVIEW My plugin is an AUv2 audio plugin built with JUCE 8. The plugin loads and functions correctly in: Pro Tools (AAX) Media Composer (AAX) Reaper (AU + VST3) Logic Pro (AU) GarageBand (AU) Audacity (AU) DaVinci Resolve / Fairlight (AU) Harrison Mixbus (AU) Ableton Live (AU) Cubase (VST3) Nuendo (VST3) It does NOT load in Final Cut Pro (tested on 10.8.x, macOS 14.6 and 15.2). DIAGNOSTICS COMPLETED auval passes cleanly: auval -v aufx Hwhy Manu → AU VALIDATION SUCCEEDED Plugin is notarized and stapled: xcrun stapler validate → The validate action worked spctl --assess --type exec → Note: returns 'not an app' which we understand is expected for .component bundles. Hardened Runtime is enabled on the bundle. We identified that our Info.plist contained a 'resourceUsage' dictionary in the AudioComponents entry. We found via system logs that this was setting au_componentFlags = 2 (kAudioComponentFlag_SandboxSafe), causing FCP to attempt loading the plugin in-process inside its sandbox, where our UDP networking is denied. We removed the resourceUsage dict, confirmed au_componentFlags = 0 in the CAReportingClient log, and FCP now loads the plugin out-of-process via AUHostingServiceXPC_arrow. Despite au_componentFlags = 0 and out-of-process loading confirmed, the plugin still does not appear in FCP's effects browser. We also identified and fixed a channel layout issue — our isBusesLayoutSupported was not returning true for 5-channel layouts (which FCP uses internally). This is now fixed. AU cache has been fully cleared: ~/Library/Caches/com.apple.audio.AudioComponentRegistrar /Library/Caches/com.apple.audio.AudioComponentRegistrar coreaudiod and AudioComponentRegistrar killed to force rescan auval -a run to force re-registration
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Mar ’26
Remote control of DRM audio - need to customise
I'm using MusicKit for DRM track playback in my iOS app and a third party library to play local user-owned music on the file system and from the music library. This app is also supporting accessory devices that offer Bluetooth remote media control. The wish is to achieve parity between how the remote interacts with user owned music and the DRM / cloud / Apple Music tracks in my application music player. Track navigation, app volume (rather than system volume), and scrubbing need to work consistently on a mix of tracks which could alternate DRM and cloud status within one album or playlist. Apple Music queue and track pickers are not useful tools in my app. How can I support playing DRM and Apple Music tracks while not surrendering the remote control features to the system?
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Mar ’26
Virtual Camera Shows Jittering Frames and Solid Accent Color on macOS
Hello Apple Developer Support, I’m developing a virtual camera using the CMIOExtensionDevice / CMIOExtensionStreamSource APIs on macOS. While the virtual camera appears in system settings and apps like Zoom and Google Meet, the video output exhibits the following issues: Jittering frames: The first frame sometimes appears correctly, but subsequent frames flicker or jitter. Solid color fill: Eventually, the camera feed fills entirely with a solid accent color (e.g., blue), rather than the intended video content. Console logs: Repeated messages appear in Console.app: Invalid display 0x00000000 Setup details: The virtual camera is created using CMIOExtensionDevice and CMIOExtensionStream. Video frames are rendered from NSImage/CGImage using CGContext and copied into CVPixelBuffers. Frame delivery is controlled by a DispatchSourceTimer at 60 FPS. macOS version: 26.2 Xcode version: 26.1 Observations: The Invalid display 0x00000000 logs suggest that CGContext drawing or NSImage operations are failing in headless mode (i.e., there is no real display attached to the virtual camera). Using CIContext with .useSoftwareRenderer = true appears to mitigate some flicker, but not entirely. Questions / Requests: Is it expected that CoreMediaIO virtual cameras cannot reliably render CGImage / NSImage frames offscreen? Are there recommended APIs or approaches to render virtual camera frames fully headless to avoid display-dependent jitter? Is there any documentation or sample code from Apple showing stable video output from a virtual camera extension that does not rely on a physical display? Any guidance or examples would be greatly appreciated. This issue prevents the virtual camera from being used reliably in standard video apps. Thank you, Savvy
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Mar ’26
Virtual Camera Shows Jittering Frames and Solid Accent Color on macOS
Hello Apple Developer Support, I’m developing a virtual camera using the CMIOExtensionDevice / CMIOExtensionStreamSource APIs on macOS. While the virtual camera appears in system settings and apps like Zoom and Google Meet, the video output exhibits the following issues: Jittering frames: The first frame sometimes appears correctly, but subsequent frames flicker or jitter. Solid color fill: Eventually, the camera feed fills entirely with a solid accent color (e.g., blue), rather than the intended video content. Console logs: Repeated messages appear in Console.app: Invalid display 0x00000000 Setup details: The virtual camera is created using CMIOExtensionDevice and CMIOExtensionStream. Video frames are rendered from NSImage/CGImage using CGContext and copied into CVPixelBuffers. Frame delivery is controlled by a DispatchSourceTimer at 60 FPS. macOS version: [Your macOS version here] Xcode version: [Your Xcode version here] Observations: The Invalid display 0x00000000 logs suggest that CGContext drawing or NSImage operations are failing in headless mode (i.e., there is no real display attached to the virtual camera). Using CIContext with .useSoftwareRenderer = true appears to mitigate some flicker, but not entirely. Questions / Requests: Is it expected that CoreMediaIO virtual cameras cannot reliably render CGImage / NSImage frames offscreen? Are there recommended APIs or approaches to render virtual camera frames fully headless to avoid display-dependent jitter? Is there any documentation or sample code from Apple showing stable video output from a virtual camera extension that does not rely on a physical display? Any guidance or examples would be greatly appreciated. This issue prevents the virtual camera from being used reliably in standard video apps. Thank you, Savvy
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Mar ’26
Corrupted image data when using QualityPrioritization.Quality on iPhone 17 Pro
Hey, I've noticed that in some scenarios photo data can be corrupted from the cameras on iPhone 17 Pro. The requirements are: The zoom level is greater than 2 times the base zoom, so 2x for the wide lens, and 8x for the telephoto. QualityPrioritization is set to .Quality. If set to .Balanced the images look as expected. The scene is well lit. I haven't managed to work out if there's an ISO cut off, but in darker scenes the images look as expected. The scene does not contain any objects or texture, e.g. a blank white screen, a blue sky, up close against a bright wall. Here is an example: This is really weird behavior. I have opened a ticket here: https://feedbackassistant.apple.com/feedback/22092908 There's also a repo here if anyone would like to try it: https://github.com/alexfoxy/CameraQualityTest. Thanks, Alex
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Mar ’26
Async AVAudioPlayerNode.scheduleBuffer stutters
My code that streams buffers into AVAudioPlayerNode is stuttering when the buffer is finished and before the next one is played. while engine.isRunning { let framesToCopy = min(buffer.frameLength - framePosition, Self.BufferSize) let srcRaw = UnsafeRawPointer(srcPtr) let playbackBuffer = AVAudioPCMBuffer(pcmFormat: buffer.format, frameCapacity: Self.BufferSize)! let playbackPtr = playbackBuffer.floatChannelData![0] let destRaw = UnsafeMutableRawPointer(mutating: playbackPtr) memcpy(destRaw, srcRaw, Int(framesToCopy) * MemoryLayout<Float>.stride) srcPtr = srcPtr.advanced(by: Int(framesToCopy)) playbackBuffer.frameLength = framesToCopy await player.scheduleBuffer(playbackBuffer, at: nil, options: [], completionCallbackType: .dataRendered) } I've tried to schedule multiple buffers at once using a combination of both the synchronous and async versions of scheduleBuffer because I thought the delay might be but it still stutters and the data copied into the playbackBuffer matches the source buffer. I've tried all combinations of options and completionCallbackType but no luck. I've tried increasing the buffer size but that just spaces out the stutters because the buffer is larger. What am I missing about this API?
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Feb ’26
AudioQueueNewOutput blocks indefinitely on iOS 18.3 (hangs during creation)
Hi everyone, We’re encountering an issue where AudioQueueNewOutput blocks indefinitely and never returns, and we’re hoping to get some insight or confirmation if this is a known behavior/regression on newer iOS versions. Issue Description When triggering audio playback, we create an output AudioQueue using AudioQueueNewOutput. On some devices, the call hangs inside AudioQueueNewOutput and never returns, with no OSStatus error and no subsequent logs. This behavior is reproducible mainly on iOS 18.3. Earlier iOS versions do not show this issue under the same code path. if (audioDes) { mAudioDes.mSampleRate = audioDes->mSampleRate; mAudioDes.mBitsPerChannel = audioDes->mBitsPerChannel; mAudioDes.mChannelsPerFrame = audioDes->mChannelsPerFrame; mAudioDes.mFormatID = audioDes->mFormatID; mAudioDes.mFormatFlags = audioDes->mFormatFlags; mAudioDes.mFramesPerPacket = audioDes->mFramesPerPacket; mAudioDes.mBytesPerFrame = audioDes->mBytesPerFrame; mAudioDes.mBytesPerPacket = audioDes->mBytesPerFrame; mAudioDes.mReserved = 0; } // Create AudioQueue for output OSStatus status = AudioQueueNewOutput( &mAudioDes, AQOutputCallback, this, NULL, NULL, 0, &audioQueue ); code-block The thread blocks inside AudioQueueNewOutput, and execution never reaches the next line. Additional Notes / Observations ASBD is confirmed to be valid Standard PCM output Sample rate, channels, bytes per frame/packet all consistent Same ASBD works correctly on earlier iOS versions AudioQueue is created on a background thread Not on the main thread Not inside the AudioQueue callback On first creation, AVAudioSession may not yet be active setCategory and setActive:YES may be called shortly before creating the AudioQueue There may be a timing window where the session is still activating Issue is reported mainly on iOS 18.3 Multiple user reports point to iOS 18.3 devices Same code path works on iOS 17.x and earlier No OSStatus error is returned — the call simply never returns. Questions Is it expected that AudioQueueNewOutput can block indefinitely while waiting for AVAudioSession / audio route / HAL readiness? Have there been any behavior changes in iOS 18.3 regarding AudioQueue creation or AudioSession synchronization? Is it unsafe to call AudioQueueNewOutput before AVAudioSession is fully active on recent iOS versions? Are there recommended patterns (or delays / callbacks) to ensure AudioQueue creation does not hang? Any insight or confirmation would be greatly appreciated. Thanks in advance!
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Feb ’26
MusicKit - ApplicationMusicPlayer fails to play certain Songs
[Note: this issue was happening on a main testing device, and after testing the same code on other devices, this issue is only happening on 1 out of 4 devices] We are successfully getting a MusicCatalogResourceResponse for every song ID where we make the MusicCatalogResourceRequest. We are able to display the song title, artist name, and album artwork for each Song in the response. However - when we go to play the song, there are some songs that play, and several songs that do not play. For the songs that don't play, the console shows “Failed to prepareToPlay error=<MPMusicPlayerControllerErrorDomain.6 "Failed to prepare to play" {}>” let musicPlayer = ApplicationMusicPlayer.shared func playSong(_ song: Song) { musicPlayer.queue = [song] Task { try await musicPlayer.prepareToPlay() try await musicPlayer.play() } Is there anything else we can investigate about what may be causing specific song IDs not to play on this specific device? Even if we remove line 6 musicPlayer.prepareToPlay() we still see the same console error when running playSong with the Songs that don't work. It is always the same song IDs that we can play and always the same song IDs that we cannot get to play, even trying them across different projects with different bundle identifiers. We can tap to play a song that works, and it starts playing immediately. Then tap a song that doesn't work, and nothing happens. Then back to a song that works. It's consistent which songs succeed and fail on this device. Perhaps there is an issue specific to this very iPad when it comes to certain specific songs, but we'd like to be confident that an app relying on MusicKit will be able to play songs that have been successfully loaded with a MusicCatalogResourceResponse. Thanks for any help or suggestions about what we may be able to investigate further on the device or what we should consider when launching an app that expects anyone with Apple Music to be able to listen to any of the songs loaded by the app. Specific iPad details: iPad Pro (12.9-inch) (6th generation) running iPadOS 26.4 Beta Two of the song IDs that won't play on this iPad (even though we can access and display their album artwork and all other information): 943204000 and 1441164805
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Feb ’26
Inquiry regarding CoreMediaErrorDomain Code=-15517 during LL-HLS Live Playback
Hello, I am currently developing a live streaming application using AVPlayer to play LL-HLS (Low-Latency HLS) content. During our testing phase, we consistently encountered the following error in the logs: CoreMediaErrorDomain Code=-15517 The challenge we are facing is that the error description is quite vague. It only provides cryptic messages such as "Key not found" or "No value information," which makes it extremely difficult to identify the root cause or perform a deep-dive analysis. I have searched through the official Apple Developer documentation and technical notes, but I couldn’t find any specific reference to what Code -15517 signifies in the context of LL-HLS or CoreMedia. Regarding this issue, I have the following questions: What is the specific meaning of this error code (-15517)? Does it relate to missing tags in the HLS manifest, or is it an internal state issue within the AVPlayer stack? Specifically, I would like to know if this is a critical error that disrupts playback, or if it is just a warning that can be safely ignored. Is there any additional logging or debugging tool you would recommend to further investigate "Key not found" issues in LL-HLS? Any insights or guidance from the community or Apple engineers would be greatly appreciated. Thank you in advance for your help.
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Feb ’26
Xcode 26.3: Simulators incorrectly shown as "build only device" — Run (Cmd+R) fails while Build (Cmd+B) and command-line build/deploy succeed
Product Xcode Version 26.3 (26C5131e) Platform macOS / iOS Simulator / iOS Device Classification Bug / Incorrect UI Behaviour Reproducibility Always (persists across restarts, scheme recreation, DerivedData clearing) Date Encountered February 20, 2026 Hardware Mac mini (M2) running macOS Test Device iPhone SE (2nd generation), iOS 26.3 Summary In Xcode 26.3, attempting to run an iOS app on any simulator destination using Cmd+R fails with the error: "A build only device cannot be used to run this target. Please select an available device or choose a simulated device as the destination." This occurs despite the selected destination being a valid iOS Simulator (not a "build only" device). The same project builds successfully using Cmd+B within Xcode and builds, installs, and runs correctly via the command line using xcodebuild, xcrun simctl, and xcrun devicectl. Steps to Reproduce Open a valid iOS project in Xcode 26.3. The project in question has target name "h", product name "DiabetesHbA1cPrediction", bundle identifier "com.diabeteshba1c.DiabetesHbA1cPrediction", with IPHONEOS_DEPLOYMENT_TARGET set to 26.0. In the scheme/destination picker toolbar, select any iOS Simulator destination (e.g. iPhone 16, iPhone 17 Pro, or any other available simulator). The destination name appears correctly in the toolbar without any "build only" annotation. Press Cmd+R (Product > Run). Xcode immediately displays the error: "A build only device cannot be used to run this target." Press Cmd+B (Product > Build) instead. The build succeeds with no errors. Expected Behaviour Cmd+R should build and launch the application on the selected simulator, just as it does in previous Xcode versions. The user had been running simulators successfully for the prior week before this issue appeared. Actual Behaviour Xcode refuses to run the app, treating every simulator destination as a "build only device." The error appears instantly upon pressing Cmd+R, before any build activity begins. Cmd+B succeeds normally, confirming the project and scheme configuration are valid. Workarounds Attempted (All Failed) The following troubleshooting steps were performed, none of which resolved the Xcode UI issue: Changed IPHONEOS_DEPLOYMENT_TARGET across multiple values (26.2, 18.0, 26.0) in all build settings within project.pbxproj. Deleted and recreated the Xcode scheme (removed .xcscheme files from xcshareddata and xcuserdata, let Xcode auto-create a new scheme). Deleted the entire DerivedData folder (rm -rf ~/Library/Developer/Xcode/DerivedData). Selected multiple different simulator destinations (iPhone 16, iPhone 16 Pro, iPhone 17 Pro) — all produced the same error. Verified the scheme’s Executable setting (confirmed it was set to the correct .app target). Changed "Show Run Destination" setting between Automatic and Always. Quit and restarted Xcode completely. Confirmed that simulator device names in the destination dropdown appeared normally, without any "build only" suffix. Working Workaround: Command-Line Build and Deploy The project builds, installs, and runs correctly when using command-line tools, confirming the project configuration is valid: Simulator deployment: xcodebuild -scheme h -destination 'platform=iOS Simulator,name=iPhone 16' build xcrun simctl boot 7F0DF8DA-E4A3-41B2-A2E4-B1F528753189 xcrun simctl install booted xcrun simctl launch booted com.diabeteshba1c.DiabetesHbA1cPrediction Result: App launched and ran correctly in the simulator. Physical device deployment (iPhone SE 2020, iOS 26.3): xcodebuild -scheme h -destination 'id=00008030-001128DC2E51402E' build xcrun devicectl device install app --device xcrun devicectl device process launch --device com.diabeteshba1c.DiabetesHbA1cPrediction Result: BUILD SUCCEEDED, app installed and launched on the physical device without issue. Key Observations The disconnect between Xcode’s UI-based Run (Cmd+R) failing and the command-line build/deploy succeeding with identical configuration strongly suggests this is an Xcode IDE bug in the run destination resolution logic, not a project configuration issue. Cmd+B succeeds in Xcode itself, meaning the build system correctly recognises the project, scheme, and destination. The failure occurs specifically in the “run” pathway where Xcode evaluates whether the destination supports execution. The simulator dropdown shows destination names without any "build only" label, yet Xcode internally treats them as build-only when the Run action is invoked. This behaviour started occurring in Xcode 26.3. The same project and simulators worked correctly in the preceding week under the same Xcode installation. Environment Xcode version: 26.3 (26C5131e) macOS: Running on Mac mini (M2) iOS SDK: 26.3 Available simulator runtimes: iOS 18.6, iOS 26.2 Physical test device: iPhone SE (2nd generation), iOS 26.3 Project type: SwiftUI iOS app with HealthKit integration Signing: Automatic, with valid provisioning for both simulator and device
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Feb ’26
Monitors from Dell not fully-integrated with MacOS keyboard control
I just bought a monitor S2725QC from Dell Technologies and isn't fully-integrated with MacOS even though it says on the website it is compatible with MacOS. https://www.dell.com/en-us/shop/all-monitors/sac/monitors/all-monitors/macos-compatible?appliedRefinements=51765 The screen brightness and volume control buttons don't work with the monitors (I have two). What can I do in terms of writing code with Dell Monitor SDK and MacOS Frameworks/Technologies?
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Feb ’26
How to get iCloud item(photo/video) size?
How I can get iCloud photo file size? Could I use private API like this in prod? Does anyone know another way? (without downloading the file to the device) func getFileSize(asset: PHAsset) -> Int64? { let resources = PHAssetResource.assetResources(for: asset) let resource = resources.first let size = resource?.value(forKey: "fileSize") as? Int64 return size }
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139
Activity
Mar ’26
Implementing PHBackgroundResourceUploadExtension
Hi, I am trying to implement a PHBackgroundResourceUploadExtension to upload backup media files to an external cloud service based on these docs: https://aninterestingwebsite.com/documentation/PhotoKit/uploading-asset-resources-in-the-background#Acknowledge-completed-jobs Creating jobs and actual uploading is working as expected, but the problem I have is in the acknowledgeCompletedJobs() function. When trying to access a job's resource, the resource is nil and thus has empty assetLocalIdentifier and originalFilename. Did anybody successfully implement this extension or knows, why this would happen? Because the resource of an acknowledgable job is empty, I can not match it back to my processed assets.
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236
Activity
Mar ’26
Implementing PHBackgroundResourceUploadExtension
Hi, I am trying to implement a PHBackgroundResourceUploadExtension to upload backup media files to an external cloud service based on these docs: https://aninterestingwebsite.com/documentation/PhotoKit/uploading-asset-resources-in-the-background#Acknowledge-completed-jobs Creating jobs and actual uploading is working as expected, but the problem I have is in the acknowledgeCompletedJobs() function. When in this function, I am trying to access a job's resource. The resource is nil and thus has empty assetLocalIdentifier and originalFilename. Did anybody successfully implement this extension or knows, why this would happen? Because the resource of an acknowledgable job is empty, I can not match it back to my processed assets.
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101
Activity
Mar ’26
Unity iOS (Metal) → WebRTC (Unity WebRTC) video stream to remote Unity client: PeerConnection connects but receiver renders black frames
Hello! My name is Mason Prather. I'm a graduate student at Kennesaw State University and a Research Engineer working in XR environments through my Graduate Research Assistant role. I’m currently building a research prototype that connects a mobile companion application to a VR headset. The mobile application is built in Unity and deployed on iOS, and it streams video frames to a remote Unity client using WebRTC. Environment Device: iPhone 15 OS: iOS 26.3 (tested on physical device, not Simulator) Engine: Unity 2022.3.57f1 Graphics API: Metal Streaming Technology: WebRTC (Unity WebRTC package) Architecture: Mobile Unity app streaming video frames to a remote Unity client Receiver Device: Meta Quest Pro headset (Unity application) Networking: LAN (UDP discovery + TCP signaling) Video Source: Unity RenderTexture Goal The goal of the system is to allow a VR user to view media stored on their phone inside a VR environment. The iOS app: renders or captures media content converts frames into a WebRTC video track streams the video to the headset Current Status Connection setup works correctly. Observed behavior: Signaling connection successful ICE candidate exchange successful PeerConnection state becomes Connected Video track created successfully However, the receiving application displays black frames. iOS App Details The video source originates from a Unity RenderTexture. Inside the phone application: RenderTexture displays correctly Frames appear correct locally But the receiving peer does not display the frames. Relevant Components Unity WebRTC package iOS Metal rendering pipeline Custom TCP signaling LAN discovery via UDP Expected Behavior Rendered frames should transmit via WebRTC and appear on the remote device. Actual Behavior The remote video track is active, but the rendered frames appear black on the receiving client. Questions Are there known issues involving Unity WebRTC + iOS Metal texture capture? Are there specific pixel format requirements when streaming textures from Unity on iOS? Could the issue relate to texture readback limitations or GPU synchronization? I am more than happy to provide screenshots and console logs upon request. If anyone has experience streaming Unity video frames via WebRTC on iOS, I would greatly appreciate any guidance.
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214
Activity
Mar ’26
Audio System Trace: Zero Time Stamp
In Instruments, I'm seeing "Zero Time Stamp" events in the "Audio Server" lane. What does that mean?
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179
Activity
Mar ’26
AVAssetDownloadConfiguration: How many video variants are actually downloaded when multiple variants exist in the HLS master playlist?
Hi, I’m trying to better understand how AVAssetDownloadConfiguration selects video variants when downloading HLS content for offline playback. Suppose I have an HLS master playlist (.m3u8) that contains several video variants defined with #EXT-X-STREAM-INF. For example, the master playlist may contain multiple video streams like this: Same resolution, different BANDWIDTH Or different resolutions (for example 720p, 1080p, etc.) My question is: How many video variants are actually downloaded when using AVAssetDownloadConfiguration without specifying any variantQualifiers? In other words: If the master playlist contains multiple video variants, will the download task fetch only one variant, or multiple variants? Does the behavior differ depending on whether the variants differ only by BANDWIDTH or also by RESOLUTION? What I observed in testing In my tests, I always end up with only one video variant downloaded, specifically the one with the highest BANDWIDTH parameter. In the m3u8 files I tested, all video variants had identical parameters (resolution, codec, frame rate, etc.) and differed only by the BANDWIDTH attribute in the master playlist. However, when inspecting the downloaded .movpkg, I noticed something interesting in boot.xml. It lists two video streams: one with complete="true" (the one with highest bandwidth) another with complete="no" (the one with lowest bandwidth) I actually had 3 video streams listed in m3u8, but the one with middle bandwidth wasn't listed in boot.xml file at all. There are also additional streams for audio and subtitles in boot.xml file. This made me wonder whether the system initially attempts to download another video variant (possibly a lower bitrate one), but then switches to the highest-quality variant and only completes that one. Additional question about variantQualifiers If I provide a predicate such as: NSPredicate(format: "peakBitRate > 0") which should theoretically match all variants, will the download task attempt to download all matching video variants, or will it still select only one? Summary So the main questions are: Without variantQualifiers, does AVAssetDownloadConfiguration always download a single video variant, and if so, how is it chosen? Does the behavior differ if variants have different resolutions vs only different bitrates? When a predicate matches multiple variants, can multiple video variants actually be downloaded in a single .movpkg? Why might boot.xml list multiple video streams when only one appears to be fully downloaded? Any clarification on the intended behavior would be greatly appreciated. Thanks!
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297
Activity
Mar ’26
Swift Array Out of Bounds Crash in VTFrameProcessor when using VTLowLatencyFrameInterpolationParameters
Hi everyone, Our team is encountering a reproducible crash when using VTLowLatencyFrameInterpolation on iOS 26.3 while processing a live LL-HLS input stream. 🤖 Environment Device: iPhone 16 OS: iOS 26.3 Xcode: Xcode 26.3 Framework: VideoToolbox 💥 Crash Details The application crashes with the following fatal error: Fatal error: Swift/ContiguousArrayBuffer.swift:184: Array index out of range The stack trace highlights the following: VTLowLatencyFrameInterpolationImplementation processWithParameters:frameOutputHandler: Called from VTFrameProcessor.process(parameters:) Here is the simplified implementation block where the crash occurs. (Note: PrismSampleBuffer and PrismLLFIError are our internal custom wrapper types). // Create `VTFrameProcessorFrame` for the source (previous) frame. let sourcePTS = sourceSampleBuffer.presentationTimeStamp var sourceFrame: VTFrameProcessorFrame? if let pixelBuffer = sourceSampleBuffer.imageBuffer { sourceFrame = VTFrameProcessorFrame(buffer: pixelBuffer, presentationTimeStamp: sourcePTS) } // Validate the source VTFrameProcessorFrame. guard let sourceFrame else { throw PrismLLFIError.missingImageBuffer } // Create `VTFrameProcessorFrame` for the next frame. let nextPTS = nextSampleBuffer.presentationTimeStamp var nextFrame: VTFrameProcessorFrame? if let pixelBuffer = nextSampleBuffer.imageBuffer { nextFrame = VTFrameProcessorFrame(buffer: pixelBuffer, presentationTimeStamp: nextPTS) } // Validate the next VTFrameProcessorFrame. guard let nextFrame else { throw PrismLLFIError.missingImageBuffer } // Calculate interpolation intervals and allocate destination frame buffers. let intervals = interpolationIntervals() let destinationFrames = try framesBetween(firstPTS: sourcePTS, lastPTS: nextPTS, interpolationIntervals: intervals) let interpolationPhase: [Float] = intervals.map { Float($0) } // Create VTLowLatencyFrameInterpolationParameters. // This sets up the configuration required for temporal frame interpolation between the previous and current source frames. guard let parameters = VTLowLatencyFrameInterpolationParameters( sourceFrame: nextFrame, previousFrame: sourceFrame, interpolationPhase: interpolationPhase, destinationFrames: destinationFrames ) else { throw PrismLLFIError.failedToCreateParameters } try await send(sourceSampleBuffer) // Process the frames. // Using progressive callback here to get the next processed frame as soon as it's ready, // preventing the system from waiting for the entire batch to finish. for try await readOnlyFrame in self.frameProcessor.process(parameters: parameters) { // Create an interpolated sample buffer based on the output frame. let newSampleBuffer: PrismSampleBuffer = try readOnlyFrame.frame.withUnsafeBuffer { pixelBuffer in try PrismLowLatencyFrameInterpolation.createSampleBuffer(from: pixelBuffer, readOnlyFrame.timeStamp) } // Pass the newly generated frame to the output stream. try await send(newSampleBuffer) } 🙋 Questions Are there any known limitations or bugs regarding VTLowLatencyFrameInterpolation when handling live 60fps streams? Are there any undocumented constraints we should be aware of regarding source/previous frame timing, pixel buffer attributes, or how destinationFrames and interpolationPhase arrays must be allocated? Is a "warm-up" sequence recommended after startSession() before making the first process(parameters:) call?
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463
Activity
Mar ’26
Final Cut Pro not loading my plugin
I have exhausted standard debugging approaches and need guidance on Final Cut Pro's AU plugin loading behavior. PLUGIN OVERVIEW My plugin is an AUv2 audio plugin built with JUCE 8. The plugin loads and functions correctly in: Pro Tools (AAX) Media Composer (AAX) Reaper (AU + VST3) Logic Pro (AU) GarageBand (AU) Audacity (AU) DaVinci Resolve / Fairlight (AU) Harrison Mixbus (AU) Ableton Live (AU) Cubase (VST3) Nuendo (VST3) It does NOT load in Final Cut Pro (tested on 10.8.x, macOS 14.6 and 15.2). DIAGNOSTICS COMPLETED auval passes cleanly: auval -v aufx Hwhy Manu → AU VALIDATION SUCCEEDED Plugin is notarized and stapled: xcrun stapler validate → The validate action worked spctl --assess --type exec → Note: returns 'not an app' which we understand is expected for .component bundles. Hardened Runtime is enabled on the bundle. We identified that our Info.plist contained a 'resourceUsage' dictionary in the AudioComponents entry. We found via system logs that this was setting au_componentFlags = 2 (kAudioComponentFlag_SandboxSafe), causing FCP to attempt loading the plugin in-process inside its sandbox, where our UDP networking is denied. We removed the resourceUsage dict, confirmed au_componentFlags = 0 in the CAReportingClient log, and FCP now loads the plugin out-of-process via AUHostingServiceXPC_arrow. Despite au_componentFlags = 0 and out-of-process loading confirmed, the plugin still does not appear in FCP's effects browser. We also identified and fixed a channel layout issue — our isBusesLayoutSupported was not returning true for 5-channel layouts (which FCP uses internally). This is now fixed. AU cache has been fully cleared: ~/Library/Caches/com.apple.audio.AudioComponentRegistrar /Library/Caches/com.apple.audio.AudioComponentRegistrar coreaudiod and AudioComponentRegistrar killed to force rescan auval -a run to force re-registration
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225
Activity
Mar ’26
Remote control of DRM audio - need to customise
I'm using MusicKit for DRM track playback in my iOS app and a third party library to play local user-owned music on the file system and from the music library. This app is also supporting accessory devices that offer Bluetooth remote media control. The wish is to achieve parity between how the remote interacts with user owned music and the DRM / cloud / Apple Music tracks in my application music player. Track navigation, app volume (rather than system volume), and scrubbing need to work consistently on a mix of tracks which could alternate DRM and cloud status within one album or playlist. Apple Music queue and track pickers are not useful tools in my app. How can I support playing DRM and Apple Music tracks while not surrendering the remote control features to the system?
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124
Activity
Mar ’26
Virtual Camera Shows Jittering Frames and Solid Accent Color on macOS
Hello Apple Developer Support, I’m developing a virtual camera using the CMIOExtensionDevice / CMIOExtensionStreamSource APIs on macOS. While the virtual camera appears in system settings and apps like Zoom and Google Meet, the video output exhibits the following issues: Jittering frames: The first frame sometimes appears correctly, but subsequent frames flicker or jitter. Solid color fill: Eventually, the camera feed fills entirely with a solid accent color (e.g., blue), rather than the intended video content. Console logs: Repeated messages appear in Console.app: Invalid display 0x00000000 Setup details: The virtual camera is created using CMIOExtensionDevice and CMIOExtensionStream. Video frames are rendered from NSImage/CGImage using CGContext and copied into CVPixelBuffers. Frame delivery is controlled by a DispatchSourceTimer at 60 FPS. macOS version: 26.2 Xcode version: 26.1 Observations: The Invalid display 0x00000000 logs suggest that CGContext drawing or NSImage operations are failing in headless mode (i.e., there is no real display attached to the virtual camera). Using CIContext with .useSoftwareRenderer = true appears to mitigate some flicker, but not entirely. Questions / Requests: Is it expected that CoreMediaIO virtual cameras cannot reliably render CGImage / NSImage frames offscreen? Are there recommended APIs or approaches to render virtual camera frames fully headless to avoid display-dependent jitter? Is there any documentation or sample code from Apple showing stable video output from a virtual camera extension that does not rely on a physical display? Any guidance or examples would be greatly appreciated. This issue prevents the virtual camera from being used reliably in standard video apps. Thank you, Savvy
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96
Activity
Mar ’26
Virtual Camera Shows Jittering Frames and Solid Accent Color on macOS
Hello Apple Developer Support, I’m developing a virtual camera using the CMIOExtensionDevice / CMIOExtensionStreamSource APIs on macOS. While the virtual camera appears in system settings and apps like Zoom and Google Meet, the video output exhibits the following issues: Jittering frames: The first frame sometimes appears correctly, but subsequent frames flicker or jitter. Solid color fill: Eventually, the camera feed fills entirely with a solid accent color (e.g., blue), rather than the intended video content. Console logs: Repeated messages appear in Console.app: Invalid display 0x00000000 Setup details: The virtual camera is created using CMIOExtensionDevice and CMIOExtensionStream. Video frames are rendered from NSImage/CGImage using CGContext and copied into CVPixelBuffers. Frame delivery is controlled by a DispatchSourceTimer at 60 FPS. macOS version: [Your macOS version here] Xcode version: [Your Xcode version here] Observations: The Invalid display 0x00000000 logs suggest that CGContext drawing or NSImage operations are failing in headless mode (i.e., there is no real display attached to the virtual camera). Using CIContext with .useSoftwareRenderer = true appears to mitigate some flicker, but not entirely. Questions / Requests: Is it expected that CoreMediaIO virtual cameras cannot reliably render CGImage / NSImage frames offscreen? Are there recommended APIs or approaches to render virtual camera frames fully headless to avoid display-dependent jitter? Is there any documentation or sample code from Apple showing stable video output from a virtual camera extension that does not rely on a physical display? Any guidance or examples would be greatly appreciated. This issue prevents the virtual camera from being used reliably in standard video apps. Thank you, Savvy
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63
Activity
Mar ’26
CoreMotion QuickTake Video Data iOS 17.5.1
I am conducting a forensic examination of a video, and it would be helpful if anyone knew how to decode the LiveTrackInfo of the metadata of a QuickTake .MOV recorded on iOS 17.5.1 There are 27 different fields, and I am not sure what each one represents. Any help would be appreciated! Thank you! log-file
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193
Activity
Mar ’26
Corrupted image data when using QualityPrioritization.Quality on iPhone 17 Pro
Hey, I've noticed that in some scenarios photo data can be corrupted from the cameras on iPhone 17 Pro. The requirements are: The zoom level is greater than 2 times the base zoom, so 2x for the wide lens, and 8x for the telephoto. QualityPrioritization is set to .Quality. If set to .Balanced the images look as expected. The scene is well lit. I haven't managed to work out if there's an ISO cut off, but in darker scenes the images look as expected. The scene does not contain any objects or texture, e.g. a blank white screen, a blue sky, up close against a bright wall. Here is an example: This is really weird behavior. I have opened a ticket here: https://feedbackassistant.apple.com/feedback/22092908 There's also a repo here if anyone would like to try it: https://github.com/alexfoxy/CameraQualityTest. Thanks, Alex
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111
Activity
Mar ’26
Async AVAudioPlayerNode.scheduleBuffer stutters
My code that streams buffers into AVAudioPlayerNode is stuttering when the buffer is finished and before the next one is played. while engine.isRunning { let framesToCopy = min(buffer.frameLength - framePosition, Self.BufferSize) let srcRaw = UnsafeRawPointer(srcPtr) let playbackBuffer = AVAudioPCMBuffer(pcmFormat: buffer.format, frameCapacity: Self.BufferSize)! let playbackPtr = playbackBuffer.floatChannelData![0] let destRaw = UnsafeMutableRawPointer(mutating: playbackPtr) memcpy(destRaw, srcRaw, Int(framesToCopy) * MemoryLayout<Float>.stride) srcPtr = srcPtr.advanced(by: Int(framesToCopy)) playbackBuffer.frameLength = framesToCopy await player.scheduleBuffer(playbackBuffer, at: nil, options: [], completionCallbackType: .dataRendered) } I've tried to schedule multiple buffers at once using a combination of both the synchronous and async versions of scheduleBuffer because I thought the delay might be but it still stutters and the data copied into the playbackBuffer matches the source buffer. I've tried all combinations of options and completionCallbackType but no luck. I've tried increasing the buffer size but that just spaces out the stutters because the buffer is larger. What am I missing about this API?
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72
Activity
Feb ’26
AudioQueueNewOutput blocks indefinitely on iOS 18.3 (hangs during creation)
Hi everyone, We’re encountering an issue where AudioQueueNewOutput blocks indefinitely and never returns, and we’re hoping to get some insight or confirmation if this is a known behavior/regression on newer iOS versions. Issue Description When triggering audio playback, we create an output AudioQueue using AudioQueueNewOutput. On some devices, the call hangs inside AudioQueueNewOutput and never returns, with no OSStatus error and no subsequent logs. This behavior is reproducible mainly on iOS 18.3. Earlier iOS versions do not show this issue under the same code path. if (audioDes) { mAudioDes.mSampleRate = audioDes->mSampleRate; mAudioDes.mBitsPerChannel = audioDes->mBitsPerChannel; mAudioDes.mChannelsPerFrame = audioDes->mChannelsPerFrame; mAudioDes.mFormatID = audioDes->mFormatID; mAudioDes.mFormatFlags = audioDes->mFormatFlags; mAudioDes.mFramesPerPacket = audioDes->mFramesPerPacket; mAudioDes.mBytesPerFrame = audioDes->mBytesPerFrame; mAudioDes.mBytesPerPacket = audioDes->mBytesPerFrame; mAudioDes.mReserved = 0; } // Create AudioQueue for output OSStatus status = AudioQueueNewOutput( &mAudioDes, AQOutputCallback, this, NULL, NULL, 0, &audioQueue ); code-block The thread blocks inside AudioQueueNewOutput, and execution never reaches the next line. Additional Notes / Observations ASBD is confirmed to be valid Standard PCM output Sample rate, channels, bytes per frame/packet all consistent Same ASBD works correctly on earlier iOS versions AudioQueue is created on a background thread Not on the main thread Not inside the AudioQueue callback On first creation, AVAudioSession may not yet be active setCategory and setActive:YES may be called shortly before creating the AudioQueue There may be a timing window where the session is still activating Issue is reported mainly on iOS 18.3 Multiple user reports point to iOS 18.3 devices Same code path works on iOS 17.x and earlier No OSStatus error is returned — the call simply never returns. Questions Is it expected that AudioQueueNewOutput can block indefinitely while waiting for AVAudioSession / audio route / HAL readiness? Have there been any behavior changes in iOS 18.3 regarding AudioQueue creation or AudioSession synchronization? Is it unsafe to call AudioQueueNewOutput before AVAudioSession is fully active on recent iOS versions? Are there recommended patterns (or delays / callbacks) to ensure AudioQueue creation does not hang? Any insight or confirmation would be greatly appreciated. Thanks in advance!
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92
Activity
Feb ’26
MusicKit - ApplicationMusicPlayer fails to play certain Songs
[Note: this issue was happening on a main testing device, and after testing the same code on other devices, this issue is only happening on 1 out of 4 devices] We are successfully getting a MusicCatalogResourceResponse for every song ID where we make the MusicCatalogResourceRequest. We are able to display the song title, artist name, and album artwork for each Song in the response. However - when we go to play the song, there are some songs that play, and several songs that do not play. For the songs that don't play, the console shows “Failed to prepareToPlay error=<MPMusicPlayerControllerErrorDomain.6 "Failed to prepare to play" {}>” let musicPlayer = ApplicationMusicPlayer.shared func playSong(_ song: Song) { musicPlayer.queue = [song] Task { try await musicPlayer.prepareToPlay() try await musicPlayer.play() } Is there anything else we can investigate about what may be causing specific song IDs not to play on this specific device? Even if we remove line 6 musicPlayer.prepareToPlay() we still see the same console error when running playSong with the Songs that don't work. It is always the same song IDs that we can play and always the same song IDs that we cannot get to play, even trying them across different projects with different bundle identifiers. We can tap to play a song that works, and it starts playing immediately. Then tap a song that doesn't work, and nothing happens. Then back to a song that works. It's consistent which songs succeed and fail on this device. Perhaps there is an issue specific to this very iPad when it comes to certain specific songs, but we'd like to be confident that an app relying on MusicKit will be able to play songs that have been successfully loaded with a MusicCatalogResourceResponse. Thanks for any help or suggestions about what we may be able to investigate further on the device or what we should consider when launching an app that expects anyone with Apple Music to be able to listen to any of the songs loaded by the app. Specific iPad details: iPad Pro (12.9-inch) (6th generation) running iPadOS 26.4 Beta Two of the song IDs that won't play on this iPad (even though we can access and display their album artwork and all other information): 943204000 and 1441164805
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212
Activity
Feb ’26
Are frames returned in presentation or decode order with AVAssetReader
I read somewhere that the frames are returned in decode order instead of presentation order when using AVAssetReader. The documentation seems sparse on the subject. I have so far failed to find a video file where the frames are not returned in presentation order. Can anyone confirm the frames are actually returned in decode order?
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115
Activity
Feb ’26
Inquiry regarding CoreMediaErrorDomain Code=-15517 during LL-HLS Live Playback
Hello, I am currently developing a live streaming application using AVPlayer to play LL-HLS (Low-Latency HLS) content. During our testing phase, we consistently encountered the following error in the logs: CoreMediaErrorDomain Code=-15517 The challenge we are facing is that the error description is quite vague. It only provides cryptic messages such as "Key not found" or "No value information," which makes it extremely difficult to identify the root cause or perform a deep-dive analysis. I have searched through the official Apple Developer documentation and technical notes, but I couldn’t find any specific reference to what Code -15517 signifies in the context of LL-HLS or CoreMedia. Regarding this issue, I have the following questions: What is the specific meaning of this error code (-15517)? Does it relate to missing tags in the HLS manifest, or is it an internal state issue within the AVPlayer stack? Specifically, I would like to know if this is a critical error that disrupts playback, or if it is just a warning that can be safely ignored. Is there any additional logging or debugging tool you would recommend to further investigate "Key not found" issues in LL-HLS? Any insights or guidance from the community or Apple engineers would be greatly appreciated. Thank you in advance for your help.
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191
Activity
Feb ’26
Xcode 26.3: Simulators incorrectly shown as "build only device" — Run (Cmd+R) fails while Build (Cmd+B) and command-line build/deploy succeed
Product Xcode Version 26.3 (26C5131e) Platform macOS / iOS Simulator / iOS Device Classification Bug / Incorrect UI Behaviour Reproducibility Always (persists across restarts, scheme recreation, DerivedData clearing) Date Encountered February 20, 2026 Hardware Mac mini (M2) running macOS Test Device iPhone SE (2nd generation), iOS 26.3 Summary In Xcode 26.3, attempting to run an iOS app on any simulator destination using Cmd+R fails with the error: "A build only device cannot be used to run this target. Please select an available device or choose a simulated device as the destination." This occurs despite the selected destination being a valid iOS Simulator (not a "build only" device). The same project builds successfully using Cmd+B within Xcode and builds, installs, and runs correctly via the command line using xcodebuild, xcrun simctl, and xcrun devicectl. Steps to Reproduce Open a valid iOS project in Xcode 26.3. The project in question has target name "h", product name "DiabetesHbA1cPrediction", bundle identifier "com.diabeteshba1c.DiabetesHbA1cPrediction", with IPHONEOS_DEPLOYMENT_TARGET set to 26.0. In the scheme/destination picker toolbar, select any iOS Simulator destination (e.g. iPhone 16, iPhone 17 Pro, or any other available simulator). The destination name appears correctly in the toolbar without any "build only" annotation. Press Cmd+R (Product > Run). Xcode immediately displays the error: "A build only device cannot be used to run this target." Press Cmd+B (Product > Build) instead. The build succeeds with no errors. Expected Behaviour Cmd+R should build and launch the application on the selected simulator, just as it does in previous Xcode versions. The user had been running simulators successfully for the prior week before this issue appeared. Actual Behaviour Xcode refuses to run the app, treating every simulator destination as a "build only device." The error appears instantly upon pressing Cmd+R, before any build activity begins. Cmd+B succeeds normally, confirming the project and scheme configuration are valid. Workarounds Attempted (All Failed) The following troubleshooting steps were performed, none of which resolved the Xcode UI issue: Changed IPHONEOS_DEPLOYMENT_TARGET across multiple values (26.2, 18.0, 26.0) in all build settings within project.pbxproj. Deleted and recreated the Xcode scheme (removed .xcscheme files from xcshareddata and xcuserdata, let Xcode auto-create a new scheme). Deleted the entire DerivedData folder (rm -rf ~/Library/Developer/Xcode/DerivedData). Selected multiple different simulator destinations (iPhone 16, iPhone 16 Pro, iPhone 17 Pro) — all produced the same error. Verified the scheme’s Executable setting (confirmed it was set to the correct .app target). Changed "Show Run Destination" setting between Automatic and Always. Quit and restarted Xcode completely. Confirmed that simulator device names in the destination dropdown appeared normally, without any "build only" suffix. Working Workaround: Command-Line Build and Deploy The project builds, installs, and runs correctly when using command-line tools, confirming the project configuration is valid: Simulator deployment: xcodebuild -scheme h -destination 'platform=iOS Simulator,name=iPhone 16' build xcrun simctl boot 7F0DF8DA-E4A3-41B2-A2E4-B1F528753189 xcrun simctl install booted xcrun simctl launch booted com.diabeteshba1c.DiabetesHbA1cPrediction Result: App launched and ran correctly in the simulator. Physical device deployment (iPhone SE 2020, iOS 26.3): xcodebuild -scheme h -destination 'id=00008030-001128DC2E51402E' build xcrun devicectl device install app --device xcrun devicectl device process launch --device com.diabeteshba1c.DiabetesHbA1cPrediction Result: BUILD SUCCEEDED, app installed and launched on the physical device without issue. Key Observations The disconnect between Xcode’s UI-based Run (Cmd+R) failing and the command-line build/deploy succeeding with identical configuration strongly suggests this is an Xcode IDE bug in the run destination resolution logic, not a project configuration issue. Cmd+B succeeds in Xcode itself, meaning the build system correctly recognises the project, scheme, and destination. The failure occurs specifically in the “run” pathway where Xcode evaluates whether the destination supports execution. The simulator dropdown shows destination names without any "build only" label, yet Xcode internally treats them as build-only when the Run action is invoked. This behaviour started occurring in Xcode 26.3. The same project and simulators worked correctly in the preceding week under the same Xcode installation. Environment Xcode version: 26.3 (26C5131e) macOS: Running on Mac mini (M2) iOS SDK: 26.3 Available simulator runtimes: iOS 18.6, iOS 26.2 Physical test device: iPhone SE (2nd generation), iOS 26.3 Project type: SwiftUI iOS app with HealthKit integration Signing: Automatic, with valid provisioning for both simulator and device
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172
Activity
Feb ’26
Monitors from Dell not fully-integrated with MacOS keyboard control
I just bought a monitor S2725QC from Dell Technologies and isn't fully-integrated with MacOS even though it says on the website it is compatible with MacOS. https://www.dell.com/en-us/shop/all-monitors/sac/monitors/all-monitors/macos-compatible?appliedRefinements=51765 The screen brightness and volume control buttons don't work with the monitors (I have two). What can I do in terms of writing code with Dell Monitor SDK and MacOS Frameworks/Technologies?
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192
Activity
Feb ’26