Dive into the technical aspects of audio on your device, including codecs, format support, and customization options.

Audio Documentation

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RemoteMediaSessionExtension: Lock Screen / Dynamic Island occasionally fail to redraw mid-track; only recovers at the next track change or by foregrounding the app
I'm seeing an intermittent split between how different Now Playing surfaces reconcile with a RemoteMediaSessionExtension (the iOS 27 com.apple.nowplaying.remote-media extension point). Control Center and Apple Watch reliably show the current track. The Lock Screen and Dynamic Island occasionally get stuck on the previous track for the remainder of that track. They'll often self-correct once the next track change happens — but not always and never mid-track. The only way to fix it before the track ends is to bring the host app to the foreground. Setup: the extension receives APNs pushes carrying playback/metadata payloads from a third-party speaker system. Each push either resumes an already-alive extension process (update(:)) or cold-starts it (session(:)), which sets content/the Artwork provider closure and returns. All three surfaces read from that exact same synchronous content value — there is no code path in the extension that could serve them differently. Cleanest isolated repro on record (device log timestamps): one track was displaying correctly everywhere. The next track triggered a cold start; the extension decoded the push, resolved and prefetched real artwork, and had content fully populated within under a second. Moments later, that cached artwork was requested and served at Control Center's own request sizes, and Control Center updated correctly. Lock Screen and Dynamic Island made zero requests of any kind — no content query, no artwork fetch — for the entire remainder of that track. This doesn’t appear to be a problem with the apns pushes, I can see from my server that they are successfully sent and Control Center updates correctly but lockscreen and Dynamic Island do not. I tried reducing the artwork size as a test to see if this worked more reliably, but still faced similar issues. Apple Watch remains a consistently-correct surface alongside Control Center, reinforcing that this is isolated to whatever presentation machinery Lock Screen and Dynamic Island specifically share. Ruled out on my side: • Push delivery/decoding — the extension's own receive-time debug dump shows the correct decoded attributes before any surface renders. • Process suspension — this has been observed with the extension actively running throughout, proven by Control Center rendering fresh data from it during the same window. Questions: Is there a known issue where Lock Screen/Dynamic Island stop re-querying a RemoteMediaSessionExtension's content mid-track, after it's already been correctly delivered and rendered elsewhere (Control Center, Watch)? Is Lock Screen/Dynamic Island's own redraw path gated on the app process being foreground, similar to requestToBecomeSystemPrimary()'s documented foreground-only effect? If so, is there any supported way to trigger that reconciliation from a background extension update, short of the user opening the app? Is there a supported way to force-invalidate/redraw Lock Screen's and Dynamic Island's cached presentation for an existing session, without ending and restarting it (which would reset the user's Lock Screen state)?
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Using MusicKit to display a user’s currently playing Apple Music track
Hello, I’m evaluating a possible MusicKit integration and would like to clarify whether the following use is permitted. With the user’s explicit and revocable consent, our iOS app would read the song currently playing in Apple Music while our app is active and display the song title and artist to other users of our application. Our app would not play, stream, host, download or redistribute Apple Music audio. Music playback would remain entirely within Apple Music. When our app is closed, it would stop accessing Apple Music. The last synchronized song may remain displayed until the user opens our app again, at which point the currently playing song would be refreshed. If a displayed song is tapped, the user would be redirected to Apple Music. We are happy to follow Apple’s required formatting, attribution and linking rules. Album artwork is not required and can be omitted if necessary. The Apple Music functionality itself would remain free. Any monetization would relate only to separate features of the application. Could someone clarify: Is this use permitted under the MusicKit / Apple Music requirements? May the current song title and artist be displayed to other users in this way? Which official Apple framework/API is recommended for detecting the song currently playing in Apple Music while our app is active? Are there specific attribution or linking requirements for this use? Thank you.
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Picture-In-Picture not starting with Custom Player
Team, I am trying to start PictureInPicture for my video from custom player as mentioned in the following link, but I am getting an error Steps: Created a player using AVPlayer. Initiated AVPictureInPictureController with AVPlayerLayer Added observer on PIP button enable status When PIP button is tapped executed pipController.startPictureInPicture() statement. PIP is not getting started & getting following error Project created in Xcode11 & currently using Xcode13.2 Error Domain=AVKitErrorDomain Code=-1001 "Failed to start picture in picture." UserInfo={NSLocalizedDescription=Failed to start picture in picture., NSLocalizedFailureReason=The UIScene for the content source has an activation state other than UISceneActivationStateForegroundActive, which is not allowed.} I didn't get any solutions online, plz help me on this issue. FYI: PIP button/mode is working if I use AVPlayerViewController(with default playerItem buttons) instead of AVPlayer & AVPictureInPictureController with custom controls Thanks in advance. Adopting Picture in Picture in a Custom Player
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macOS 27 regression: HDMI + DisplayPort Multi-Output audio fails with Core Audio error 1937010544
Hi, I believe I have found a Core Audio regression in macOS 27. This exact hardware configuration worked correctly on macOS 26, and the issue started immediately after upgrading to macOS 27. Hardware: Mac mini M2 2 × MSI MP243X monitors Monitor 1 connected via HDMI Monitor 2 connected via DisplayPort Both monitors expose a 2-channel audio output to macOS On macOS 26: I used Audio MIDI Setup to create a Multi-Output Device containing both MSI MP243X audio outputs. Audio played simultaneously through both monitors without any issues. On macOS 27: Both audio devices are still detected correctly and both work perfectly when selected individually: HDMI only: WORKS DisplayPort only: WORKS HDMI + DisplayPort simultaneously: FAILS This is reproducible even immediately after a full reboot. When I create a new Multi-Output Device containing both MSI outputs and select it as the system output, audio playback cannot start. For example: afplay /System/Library/Sounds/Glass.aiff returns: Error: AudioQueueStart failed ('stop') I captured Core Audio debug logs while reproducing the problem. Core Audio initially reports that StartIO succeeded, but the physical display audio device then fails to establish a timeline. Relevant log messages include: HALS_IOEngine2::_StartIO succeeded Device 3669B540-0000-0000-2623-0104A5351D78 is not running. could not establish a timeline after waiting 10000000 microseconds stopping with error 1937010544 StartIOThread: the IO thread failed to start, Error: 1937010544 I have already tested the following: Both devices at 44.1 kHz / 24-bit Both devices at 48 kHz / 16-bit Recreating the Multi-Output Device from scratch Using the HDMI device as clock source Using the DisplayPort device as clock source Different drift correction configurations Restarting coreaudiod Full macOS reboot Testing both outputs individually immediately after reboot Alternative multi-device audio routing software The behavior is always reproducible. Each MSI MP243X audio endpoint works correctly by itself. The failure only occurs when both HDMI and DisplayPort audio endpoints are opened simultaneously. system_profiler correctly detects both devices at 48 kHz: MSI MP243X Output Channels: 2 Current Sample Rate: 48000 Transport: HDMI MSI MP243X Output Channels: 2 Current Sample Rate: 48000 Transport: DisplayPort This does not appear to be a problem with either monitor or connection individually, because both outputs continue to work independently. The important difference is the macOS version: macOS 26: HDMI + DisplayPort Multi-Output = WORKING macOS 27: HDMI only = WORKING DisplayPort only = WORKING HDMI + DisplayPort Multi-Output = FAILS with AudioQueueStart 'stop' / Core Audio error 1937010544 No hardware, monitor, cable, or connection changes were made between the working macOS 26 configuration and the macOS 27 configuration. This therefore appears to be a regression in the Core Audio/display-audio path introduced with macOS 27 when two display audio endpoints (HDMI + DisplayPort) are opened simultaneously. Has anyone else been able to reproduce this on macOS 27, particularly on Apple Silicon? I can provide the complete coreaudiod logs and run additional Core Audio diagnostics if needed. Additional isolation tests: Both monitors can remain physically connected to the Mac at the same time. With both HDMI and DisplayPort connected: Selecting the HDMI MSI MP243X as the only output works correctly. Selecting the DisplayPort MSI MP243X as the only output works correctly. Opening both audio endpoints simultaneously causes the failure. Therefore, simply having both displays connected does not trigger the issue. The failure appears specifically when Core Audio attempts to run both display-audio endpoints at the same time. I also tested this using third-party multi-device audio routing implementations instead of relying only on Audio MIDI Setup. The same behavior occurs: either MSI MP243X can be opened and used independently, but attempting to route audio to both devices simultaneously fails. This suggests that the issue is below the Multi-Output Device configuration itself and may be related to starting/synchronizing two display-audio IO engines simultaneously. During the failure, the Core Audio log sequence is particularly interesting: The physical device is detected normally. The audio format is configured successfully. Core Audio reports that StartIO succeeded. The device subsequently reports that it is not running. Core Audio waits 10 seconds for a timeline. Timeline establishment fails. The IO thread terminates with error 1937010544 ('stop'). One captured conversion path was: 2 ch, 48000 Hz, Float32, interleaved -> 2 ch, 48000 Hz, Int16, interleaved so both sides were operating at 48 kHz during this test. Another important observation is that restarting coreaudiod does not resolve the simultaneous-output problem. A complete reboot also does not resolve it: immediately after a fresh boot, before launching any third-party audio-routing software, both physical outputs work individually but a newly created Multi-Output Device still reproduces the failure. This makes the issue highly reproducible on this machine. Minimal reproduction: Boot macOS 27 with both MSI MP243X monitors connected. Open Audio MIDI Setup. Verify both MSI MP243X devices work independently. Set both devices to 48,000 Hz. Create a new Multi-Output Device. Select both MSI MP243X devices. Select the new Multi-Output Device as the system audio output. Run: afplay /System/Library/Sounds/Glass.aiff Expected result: The sound is reproduced simultaneously through both monitors, as it was on macOS 26. Actual result: Error: AudioQueueStart failed ('stop') Switching the system output back to either individual MSI MP243X restores audio playback. The problem can then be reproduced again by selecting the Multi-Output Device.
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MusicKit API — Compatibility question regarding user-initiated scoring method
Hi everyone, I'm building Sidetick, a concert ticketing and cultural discovery platform. I have an active Apple Developer Program account with MusicKit access. I want to implement the following flow and need to know if it complies with the MusicKit License Agreement: User authenticates via MusicKit (explicit OAuth consent) We read their heavy-rotation and library/artists in memory We calculate a fan affinity score per artist (e.g. "480 XP with Angèle") — entirely in-memory, never written to our DB We show the user: "We found these artists — which ones do you want to follow on Sidetick?" User explicitly picks their favorites ALL Apple Music API data is immediately deleted from our systems What we store is only the user's Sidetick declaration: {artist: "Angèle", xp: 480} — no Apple Music raw data retained After this, ALL gamification (fan ranking, ticket priority, rewards) is based exclusively on Sidetick first-party actions (ticket purchases, attended concerts, referrals) — zero Apple Music data involved. The intent: MusicKit is used as a one-time discovery bootstrap to help users identify which artists to follow on Sidetick. Apple Music data is never stored, never shared with third parties, never used for advertising. My questions: Is this use case compatible with the MusicKit License Agreement? Is storing the calculated XP score (after deleting the source Apple Music data) considered retaining Apple Music data? Is there a specific clause we should be careful about? Thanks in advance — any Apple engineer or experienced MusicKit dev input is very welcome. =D
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fail to get HLS realtime stream via AVPlayerItemSampleBufferOutputDelegate
Hi, I'm trying to do some realtime audio processing on audio served from an HLS stream (i.e. an AVPlayer created using an M3U HTTP URL). And I find that new APIs(AVPlayerItemSampleBufferOutput) are available in iOS 27.0 to achieve it. However, I failed to get the available data via the AVPlayerItemSampleBufferOutputDelegate. And I found some error in the system log: I create AVPlayerItemSampleBufferOutput and set the delegate after receiving the AVPlayerItemStatusReadyToPlay event. And here's my code: @interface OCAudioSamplebuffer () <AVPlayerItemSampleBufferOutputDelegate> @property (nonatomic, strong) AVPlayerItemSampleBufferOutput *bufferOutput; @property (nonatomic, strong) dispatch_queue_t bufferOutputQueue; @property (nonatomic, strong) AVPlayerItem *playerItem; @end - (void)playItem:(AVPlayerItem *)item { if (@available(iOS 27, *)) { AVAudioSession *audioSession = [AVAudioSession sharedInstance]; if([NSThread mainThread]){ [audioSession setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryPlayback error:nil]; [audioSession setActive:YES error:nil]; }else{ dispatch_async(dispatch_get_main_queue(), ^{ [audioSession setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryPlayback error:nil]; [audioSession setActive:YES error:nil]; }); } AVPlayerItemSampleBufferOutputAudioConfiguration *cfg = [[AVPlayerItemSampleBufferOutputAudioConfiguration alloc] init]; CMFormatDescriptionRef formatDescription = [self createPCMFormatDescriptionWithSampleRate:44100.0 channels:2 isFloat:YES]; cfg.requestedAudioFormat = formatDescription; if (formatDescription) { NSLog(@"create PCM Format Description success"); CFRelease(formatDescription); } else { NSLog(@"fail to create PCM Format Description"); } self.bufferOutput = [[AVPlayerItemSampleBufferOutput alloc] initWithConfiguration:cfg]; NSLog(@"create buffer success, PCM Format Description%@---,%@", cfg.requestedAudioFormat, formatDescription); self.bufferOutputQueue = dispatch_queue_create("audioSamplebufferQueue", DISPATCH_QUEUE_CONCURRENT); [self.bufferOutput setDelegate:self queue:self.bufferOutputQueue]; [item addOutput:self.bufferOutput]; self.playerItem = item; } else { // Fallback on earlier versions } } Any help. Thank you
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Tracks missing from Apple Music API listening history
I have a product that relies on the Apple Music API's "recently played tracks" endpoint. Recently, a few users are reporting that there are songs missing from their history. I was able to observe this myself—the issue corrected itself after re-authenticating with Apple Music, but unfortunately for at least one user this is not helping in their case. What's odd is that there is some inconsistency about what shows in the recently played tracks endpoint. Some examples My own account: ✅ Music from my playlists ✅ Albums and singles ✅ Apple editorial playlists ❌ Playlists created by other users User 1: ❌ Music from their playlists ✅ Albums and singles ❌ Apple editorial playlists ❌ Playlists created by other users In most cases, all four of these would appear in the recent tracks API. What could cause these tracks to be missing from the listening history endpoint? Listening history is already enabled for the devices they're using, but the songs are appearing inconsistently.
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Push-to-start RemoteMediaSession never appears on Lock Screen/Control Center without opening the app — expected behavior?
I'm implementing the new NowPlaying framework's remote-session push-to-start flow (per Publishing remote media sessions) to show a Sonos-like remote speaker's playback on the Lock Screen/Control Center without requiring my app to be running. The docs say: Your server can start, update, or end sessions when your app isn't running. Use this approach when playback starts from a remote device without someone opening your app. That section never mentions requestToBecomeSystemPrimary() — that's only documented under "Start and update sessions from your app," with a note that it's a no-op unless the app is foregrounded. In my testing, though, a session created purely via a push-to-start "event":"start" push never shows up anywhere in system UI (not Control Center, not the Lock Screen) until I open the app at least once. The mechanism itself works correctly — RemoteMediaSessionExtension.session(_:) fires reliably, decodes the attributes correctly, and returns a valid RemoteMediaSessionRepresentable (confirmed via on-device logging: no errors, clean construction every time, across dozens of test pushes). It just isn't surfaced. To rule out anything on my end, I've tested: Sending via my own server (correct apns-topic/apns-push-type headers, confirmed working via HTTP/2 200 and correct decode) Sending via the Push Notifications Console directly, with Environment explicitly set to Production (my push-to-start token only validates against production, matching the known dev-signed-token-provisions-against-production quirk) A hand-built, minimal, fully valid payload for a completely fresh, never-before-registered session id Every combination produces a correctly-constructed session that's invisible until the app opens — at which point my own app code (unrelated to the push) independently constructs and promotes its own session via RemoteMediaSession.start() + requestToBecomeSystemPrimary() in the foreground. Has anyone gotten a push-to-start session to actually appear on the Lock Screen/Control Center without opening the app first? Is there an additional step beyond what's in the current docs (some other registration, entitlement, or timing requirement) that's needed for that, or is this expected behavior right now and the docs are ahead of the implementation? FB24876585 filed on Feedback Assistant with app logs attached.
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Music.app hangs on Library tab with Sync Library enabled — iOS 27.2 beta
On iPhone 17 Pro Max running iOS 27.2 beta (24B5084k), Music.app hangs and is watchdog-terminated when opening the Library tab, but only with Sync Library enabled. to reproduce: 1. Settings › Apps › Music › Sync Library OFF — app works normally. 2. Enable Sync Library, let it finish syncing. 3. Open Music and navigate to the Library tab. Result: The app freezes immediately and is terminated. Home, Radio and Search all play normally with Sync Library on — the hang is isolated to the Library tab. The stackshot from Analytics Data shows multiple threads blocked on a single thread, including com.apple.SwiftUI.AsyncRenderer, with the watchdog reporting "Failed to terminate gracefully after 5.0s". No VPN, no automatic downloads, no local files. The same Apple Music account works normally on iPadOS 26 and on Apple Music for Windows. 100% reproducible. Filed as FB24865181. Has anyone else hit this? If so, does your Music- analytics log show the same blocked-thread signature?
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AVSpeechSynthesizer does not work on "Mac (Designed for iPad)", with some voices
The iOS 26 sample below speaks well on iPhone/iPad devices and the iOS simulator. But it does not speak on "Mac (Designed for iPad)", with a voice downloaded via the macOS settings. Instead it issues this warning : Invalid maui voice identifier com.apple.voice.enhanced.en-US.Samantha How to make an iOS app speak on "Mac (Designed for iPad)", with a downloaded voice ? Note : I use iOS 26.5.2 and macOS 26.5.2. I use voices that can be found in System Settings > Accessibility > Read & Speak > System voice. I have checked that "Samantha (Enhanced)" is the "System voice" in the macOS settings. I have checked that the same issue occurs with other voices and other languages. There is no such issue for a voice that never needs to be downloaded. import AVFAudio import SwiftUI @main struct SampleApp: App { var body: some Scene { WindowGroup { SampleView() } } } struct SampleView: View { private var synthesizer = AVSpeechSynthesizer() var body: some View { Button("Speak", action: speak) } private func speak() { let utterance = AVSpeechUtterance(string: "I speak English.") utterance.voice = AVSpeechSynthesisVoice(language: "en") self.synthesizer.speak(utterance) } }
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Issues with AVRoutePickerView channel switching
We are developing a voice call application that uses AVRoutePickerView, allowing users to switch between an iPhone, a speaker, and Bluetooth earphones. However, we have encountered an intermittent issue: when switching from the speaker to Bluetooth earphones, the earphones remain in a loading state, and the audio channel subsequently switches back to the speaker. How can we resolve this issue? Here is the sample code: let session = AVAudioSession.sharedInstance() do { try session.setCategory(.playAndRecord, mode: .default, options: [.allowBluetooth]) try session.overrideOutputAudioPort(isBluetoothConnected ? .none : .speaker) try session.setPreferredSampleRate(48000) try session.setPreferredIOBufferDuration(0.02) try session.setActive(true, options: []) INFO(" >>> start: hasBluetooth=\(isBluetoothConnected), inputs: \(session.currentRoute.inputs.map { $0.portType }) outputs: \(session.currentRoute.outputs.map { $0.portType })") } catch { ERROR("(error.localizedDescription)") }
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Public API availability for AirPods custom EQ in iOS 27
Hi, Is there a public API in iOS 27 to read or modify the Low, Mid, and High values of the AirPods custom EQ shown in Settings? Specifically, I’m asking about the device-level EQ on AirPods Pro, rather than in-app audio processing using AVAudioUnitEQ. If no public API is available, is there a system-provided Shortcuts action or another officially supported way to access these settings? Thank you.
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Signaling Mach semaphores from an IOProc
What is the official stance on the safety of signaling Mach semaphores from within a Core Audio real-time context? The most recent guidance I can find says: To ensure glitch-free performance, audio processing must occur in a real-time safe context. Don’t allocate memory, perform file I/O, take locks, or interact with the Swift or Objective-C runtimes when rendering audio. Mach semaphores have internal synchronization primitives (a spinlock and perhaps others) but I also believe that the scheduling priority level is elevated internally to prevent priority inversion. So while it seems that Mach semaphores could be prohibited I wonder if that is truly the case here. So while a call to semaphore_signal does involve locks, in a Core Audio real-time context, is it safe?
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iOS 27 Public Beta 6: CallKit UI remains after ending two outgoing calls in modified Apple Speakerbox sample
Summary On an iPhone 17 running iOS 27 Public Beta 6, the system CallKit UI remains visible after ending two outgoing calls individually. This is reproducible using Apple's “Making and Receiving VoIP Calls with CallKit” sample (Speakerbox), with only two minimal changes to support multiple simultaneous calls. After both calls end, Speakerbox displays “No Calls”, but the system CallKit UI still shows 111, and the Dynamic Island retains a call-related status. Environment Device: iPhone 17 (physical device) OS: iOS 27 Public Beta 6 App: Apple's Speakerbox sample with the modifications below Backend: None. The sample's original simulated calls are used; no external VoIP SDK is involved. Changes to the original sample Only two files were modified. 1. ProviderDelegate.swift Added: providerConfiguration.maximumCallGroups = 3 The original setting remains unchanged: providerConfiguration.maximumCallsPerCallGroup = 1 2. SpeakerboxCallManager.swift Before starting a new outgoing call, hold existing calls that are not already on hold. The hold actions and new start action are submitted in the same transaction: let transaction = CXTransaction() for call in calls where !call.isOnHold { transaction.addAction( CXSetHeldCallAction(call: call.uuid, onHold: true) ) } transaction.addAction(startCallAction) requestTransaction(transaction) No changes were made to the simulated connection timing, startedConnectingAt/connectedAt reporting, CXEndCallAction handling, call removal, or audio handling. The original end-call handler finds the call by UUID, calls endSpeakerboxCall(), fulfills the end action, and removes the call from the app's list. Steps to reproduce Launch the modified Speakerbox sample. Create an outgoing call to 111. Create a second outgoing call to 222. The first call is placed on hold. Wait until Speakerbox shows 111 — On Hold and 222 — Active, with call durations displayed. In Speakerbox, select 222 - End Call. Select 111 - End Call. Confirm that Speakerbox displays “No Calls”. Open the app switcher and inspect the system CallKit UI. Also inspect the Dynamic Island. Open the remaining system call UI and tap End. Expected result After both calls end, the system should no longer display an ongoing call in the CallKit UI or Dynamic Island. Actual result Speakerbox displays “No Calls”. The system CallKit UI continues to display the first call, 111. The Dynamic Island continues to show a call-related “Hold” status. Tapping End in the remaining system call UI does not clear the residual state during the recording. The issue occurs even after waiting for both simulated calls to connect before ending them. This is the system-provided CallKit UI, not an active-call view implemented by the sample app. Reproduction video Recording: 4b03d30e507b874d9c19c0523632e9d6.mp4 00:24–00:26 (approximately): Both calls are present; 111 is on hold and 222 is active. 00:26–00:31 (approximately): End 222, then end 111. Speakerbox displays “No Calls”. 00:31–01:03 (approximately): The system CallKit UI and Dynamic Island retain the call state despite further attempts to end it. Questions Is this an iOS 27 regression, or is additional lifecycle handling required when extending Speakerbox to support multiple calls? Please advise what additional diagnostics would help investigate why the system UI retains an ongoing-call state after both calls have been ended using the sample's original end-call handling. Source and video downloads https://github.com/willbin/callkit-ios27-repro/releases/tag/repro-v1
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AirPods audio repeatedly cuts out under CPU and memory pressure on M5 Max MacBook Pro
I filed FB24725256 with a live macOS Bluetooth diagnostic, Sysdiagnose, and System Information Report. Environment: MacBook Pro (Mac17,6), Apple M5 Max, 128 GB RAM macOS 26.5 (25F71) AirPods Pro 3, firmware 8B41 AirPods selected for both input and output because microphone input is required for dictation and voice typing Problem: Bluetooth playback repeatedly stutters and cuts out during sustained local development and AI-agent workloads. The AirPods signal is strong (roughly -46 to -52 RSSI), and the Mac remains otherwise usable. Unified logs recorded repeated AudioSkywalkReadLoop overwait events in bluetoothd, commonly 50–69 ms and previously up to 795 ms. CoreAudio also reported HALS_OverloadMessage failures because a client exceeded its I/O-cycle budget and a safety violation occurred. Steps to reproduce: Connect AirPods Pro and keep them selected for input and output. Stream audio. Run sustained CPU- and memory-intensive development work, such as multiple builds, browser workloads, simulators, or local AI agents. Observe repeated playback interruptions as CPU load and memory compression increase. Expected: macOS should protect real-time CoreAudio and Bluetooth transport deadlines on this hardware without requiring productive work to be paused or throttled. The same AirPods stream reliably from much smaller Apple devices; Apple's highest-end Mac should maintain audio continuity too. This is a platform-quality failure on a high-end Mac. This appears related to longstanding reports: Simulator/Xcode causing AirPods distortion: https://developer.apple.com/forums/thread/668170 CoreAudio overloads and dropouts associated with memory pressure: https://developer.apple.com/forums/thread/677383 Bluetooth headset interruptions on newer macOS releases: https://developer.apple.com/forums/thread/763848 If you can reproduce this, please boost this thread and file your own Feedback Assistant report with fresh Bluetooth logs and a Sysdiagnose. Include the exact occurrence time and reference FB24725256 so Apple can connect the reports.I filed FB24725256 with a live macOS Bluetooth diagnostic, Sysdiagnose, and System Information Report. Environment: MacBook Pro (Mac17,6), Apple M5 Max, 128 GB RAM macOS 26.5 (25F71) AirPods Pro 3, firmware 8B41 AirPods selected for both input and output because microphone input is required for dictation and voice typing Problem: Bluetooth playback repeatedly stutters and cuts out during sustained local development and AI-agent workloads. The AirPods signal is strong (roughly -46 to -52 RSSI), and the Mac remains otherwise usable. Unified logs recorded repeated AudioSkywalkReadLoop overwait events in bluetoothd, commonly 50–69 ms and previously up to 795 ms. CoreAudio also reported HALS_OverloadMessage failures because a client exceeded its I/O-cycle budget and a safety violation occurred. Steps to reproduce: Connect AirPods Pro and keep them selected for input and output. Stream audio. Run sustained CPU- and memory-intensive development work, such as multiple builds, browser workloads, simulators, or local AI agents. Observe repeated playback interruptions as CPU load and memory compression increase. Expected: macOS should protect real-time CoreAudio and Bluetooth transport deadlines on this hardware without requiring productive work to be paused or throttled. The same AirPods stream reliably from much smaller Apple devices; Apple's highest-end Mac should maintain audio continuity too. This is a platform-quality failure on a high-end Mac. This appears related to longstanding reports: Simulator/Xcode causing AirPods distortion: https://developer.apple.com/forums/thread/668170 CoreAudio overloads and dropouts associated with memory pressure: https://developer.apple.com/forums/thread/677383 Bluetooth headset interruptions on newer macOS releases: https://developer.apple.com/forums/thread/763848 If you can reproduce this, please boost this thread and file your own Feedback Assistant report with fresh Bluetooth logs and a Sysdiagnose. Include the exact occurrence time and reference FB24725256 so Apple can connect the reports.
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AirPlay fails when Mac is connected to iPhone Personal Hotspot
AirPlay fails when Mac is connected to iPhone Personal Hotspot I’m using AVRoutePickerView to route audio from an iPhone app to a Mac with AirPlay Receiver enabled. What works When the iPhone and Mac are connected to the same Wi-Fi network, AirPlay routing works normally. Routing audio back to the iPhone speaker or to connected AirPods over Bluetooth also works correctly. What fails When the iPhone provides a Personal Hotspot and the Mac connects to that iPhone’s hotspot, the Mac still appears as an available destination in AVRoutePickerView. However, selecting the Mac fails with: Unable to connect to “[Mac Name]” Questions Is AirPlay routing from an iPhone hosting a Personal Hotspot to a Mac connected to that hotspot a supported network topology? If it is supported, are there any additional AVAudioSession, networking, entitlement, or AirPlay configuration requirements for this scenario? The fact that the Mac is successfully discovered and displayed by AVRoutePickerView, but the connection itself fails, is the part I’m particularly trying to understand. Thank you for any guidance on the expected behavior here.
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RemoteMediaSession started while the app is in the background no longer appears in Control Center (worked in earlier betas)
My app publishes a NowPlaying.RemoteMediaSession for music playing on speakers on the local network. While the app is in the background and someone taps play on my widget, that intent runs in my app process and wakes the app in the background — it can fetch the speaker state and start and update the remote session without any trouble. As of Beta 6, the session is created successfully but never shows up in Control Center or on the Lock Screen. It only appears the moment I bring my app to the foreground. In earlier betas the same code showed the session in control center, without needing to open the app. I don't call requestToBecomeSystemPrimary() and I don’t expect it to be set as primary, only when my app is in the foreground but at least the session should appear in control center or the lock screen as an option for the user to set it to system primary. FB24439526 has been submitted with Sysdiagnose attached.
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Supported MusicKit APIs for vinyl-style speed, pitch and reverse playback of subscription songs on iOS?
I am building a personal iPhone prototype with an on-screen record platter. Before enrolling in the Apple Developer Program or developing the Apple Music integration further, I would like to establish whether the core interaction is supported by public APIs. The intended interaction is: Tap the platter to play or pause an Apple Music subscription song. Hold the platter to stop playback at its current position. Move the platter forward or backward to control the direction and speed of audible playback continuously. Change pitch together with speed, like a physical record, rather than preserving the original pitch. Release the platter to smoothly return to normal playback. Hold a separate control to listen continuously at a faster speed. A prototype using an AVAudioEngine-based renderer works with unprotected local audio. I have NOT verified these behaviors with Apple Music subscription content. I understand that this local renderer does not establish feasibility for MusicKit, and I am not seeking to extract protected audio or bypass content protection. MusicPlayer.State.playbackRate is documented as settable, with positive values for forward playback and negative values for reverse playback: https://developer.apple.com/documentation/musickit/musicplayer/state-swift.class/playbackrate For ApplicationMusicPlayer on iOS, is this vinyl-style interaction supported for full Apple Music subscription songs, rather than previews or user-owned unprotected files? In particular: What playback-rate range is supported for subscription songs? Do negative rates produce audible reverse playback, and how should zero-speed holding be implemented? Is there a documented public API to make pitch follow playback speed, or to disable pitch preservation? Are frequent rate and direction changes supported for interactive scratching? Are there documented limitations on update frequency, buffering, seeking precision or responsiveness? If this interaction is outside public MusicKit capabilities, is there an official channel where an individual developer can ask about eligibility for an approved Apple Music DJ integration? I am asking for the supported API path and its limitations, not implementation details of another app. If only ordinary variable-speed playback or seeking is supported, a clear distinction from continuous vinyl-style scratching would be very helpful. The initial goal is personal use; possible App Store distribution is undecided. I have an active Apple Music subscription but am not currently enrolled in the paid Apple Developer Program. Thank you.
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Building a library playlist on macOS that mixes catalog songs and the user's own uploads in a fixed order – supported route, and how to know when an upload is registered?
Our sandboxed macOS app digitises audio cassettes and builds one playlist per cassette in the user's Apple Music library that follows the tape's order: catalog songs where a title was recognised, and the user's own recordings (AAC files the app exported from the tape) where it was not. The user has an Apple Music subscription and Sync Library on. On macOS every write on MusicLibrary is marked @available(macOS, unavailable) in the 26.5 SDK – add, add(_:to:), createPlaylist and edit (see thread 844114, which got no answer). So we build the playlist through Music.app's scripting interface: make new user playlist, duplicate <library track> to <playlist> for catalog songs, add <file> to <playlist> for own recordings. That works, with one exception that leads to our questions. What we observe Reproducible on macOS 26.6.2 / Music 26; a standalone AppleScript is at the end. A playlist built in one go from 14 subscription tracks keeps all 14. The same playlist with one local file added after the second track: all 15 entries are there right after the build and one second later. About 15 s later the playlist has 3 entries – the two catalog entries before the file, the file, and nothing that was added after it. No error anywhere. If the file has been in the library for several minutes before the playlist is built, everything stays. Adding it to the library and waiting 45 s is not enough. Meanwhile the track's cloud status stays unknown, and GET /v1/me/library/search?types=library-songs does not list it (checked for 10 minutes). Emptying the playlist and building it again ~30 s after the entries were removed keeps everything, every time. That is what we do today; it costs 30–40 s per import, and we have to tell the user that entries were removed and put back. Our reading: while the freshly added file is not yet registered in iCloud Music Library, the playlist as pushed to the server is cut at the first item the server cannot reference, and the next sync adopts the shorter list for cloud items while keeping the local-only item in place. Questions Is there a supported way for a macOS app to create a library playlist and add tracks to it? Specifically: is the Apple Music API (POST /v1/me/library/playlists with relationships.tracks, and POST /v1/me/library/playlists/{id}/tracks) the intended route from a macOS app holding a MusicKit user token, and can such a playlist reference the user's own uploaded songs by their library id (i.…)? After a local file has been added to the library (via Music.app's add, or any other supported way), how can an app learn that iCloud Music Library has registered it, and what its library song id is? A notification, a MusicKit property, an Apple Music API endpoint? We would wait on that signal instead of rebuilding. Is the removal described above expected behaviour? Catalog ids are re-resolved at import time via id, ISRC and search as recommended in thread 122110, so stale catalog ids are not the cause. Reproduction Needs Sync Library on, at least 14 subscription tracks in the library, and a local audio file the library does not know yet. Prints the counts after 1 s, 21 s and 41 s, then cleans up. on run argv set localFile to POSIX file (item 1 of argv) tell application "Music" set cloudTracks to (every track of library playlist 1 whose cloud status is subscription) set idsBefore to persistent ID of every track of library playlist 1 set pl to make new user playlist with properties {name:"Reconciliation repro"} repeat with i from 1 to 2 duplicate (item i of cloudTracks) to pl end repeat set fileTrack to add localFile to pl set fileID to persistent ID of fileTrack repeat with i from 3 to 14 duplicate (item i of cloudTracks) to pl end repeat set n0 to count of tracks of pl delay 1 set n1 to count of tracks of pl delay 20 set n2 to count of tracks of pl delay 20 set n3 to count of tracks of pl delete pl if fileID is not in idsBefore then delete (first track of library playlist 1 whose persistent ID is fileID) return "after build: " & n0 & ", after 1 s: " & n1 & ", after 21 s: " & n2 & ", after 41 s: " & n3 end tell end run Output here: after build: 15, after 1 s: 15, after 21 s: 3, after 41 s: 3.
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visionOS Developer Strap: UVC video works, but how can I access the capture device’s USB Audio Class (UAC) audio?
I’m developing a native visionOS application that uses an external HDMI capture device connected to Apple Vision Pro through the Developer Strap. The goal is to use Apple Vision Pro as a low-latency display for external HDMI sources such as an Xbox Series X, including both the HDMI video and the original digital game audio. My current hardware path is: Xbox Series X → HDMI → Elgato 4K X → USB-C → Apple Vision Pro Developer Strap The Elgato 4K X receives both video and audio from the Xbox over HDMI. What is working UVC video capture is working successfully on visionOS. The external Elgato capture device can be used as the video source and the Xbox video is displayed correctly inside the Vision Pro application. I have also verified the Elgato 4K X independently on macOS, where the device is recognized correctly. The problem I cannot find a supported way on visionOS to access the USB Audio Class (UAC) audio interface associated with the capture device. I specifically need the digital game audio originating from: Xbox HDMI → Elgato 4K X → USB/UAC → visionOS I do not want to use the Apple Vision Pro’s built-in microphone. Selecting/capturing the Vision Pro microphone would only record environmental sound and is not a substitute for the digital HDMI audio stream. Apple’s visionOS documentation for external devices through the Developer Strap appears to focus on UVC video capture. I haven’t been able to determine whether the accompanying UAC interface of a UVC/UAC composite capture device is exposed to visionOS applications. What I’ve tried / verified Connected an Xbox Series X to the HDMI input of an Elgato 4K X. Connected the 4K X to Apple Vision Pro through the Developer Strap. Successfully discovered and received the external UVC video stream. Successfully displayed the Xbox video feed in visionOS. Confirmed that the 4K X itself is recognized and functional on macOS. Attempted to obtain audio corresponding to the external capture source. The Vision Pro microphone is available as an audio source, but this is not the audio source required. I have not found a documented visionOS API that exposes the 4K X’s USB/UAC audio endpoint through the Developer Strap. Questions Does visionOS currently support USB Audio Class input devices connected through the Apple Vision Pro Developer Strap? If a device exposes both UVC video and UAC audio interfaces, is there a supported way to associate/access both interfaces from a visionOS application? If UAC is supported, which framework/API should be used to discover the external audio endpoint — AVFoundation, Core Audio, or another API? Does accessing the UAC interface require an entitlement in addition to UVC device access? If generic UAC access through the Developer Strap is currently unavailable to third-party visionOS applications, is there a restricted/managed entitlement that developers can request? If this isn’t currently supported, what is Apple’s recommended architecture for receiving synchronized video and audio from an HDMI capture device on Apple Vision Pro? Ultimately, I’m trying to achieve: HDMI source → UVC video + UAC audio → visionOS application → video displayed in Vision Pro + audio played through Vision Pro speakers/AirPods Since UVC video from this exact hardware is already working, I’m primarily trying to determine whether access to the accompanying USB audio interface is possible with the current visionOS SDK, requires another entitlement/API, or is currently unsupported. Any guidance from Apple or developers who have worked with composite UVC/UAC devices on Vision Pro would be greatly appreciated.
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RemoteMediaSessionExtension: Lock Screen / Dynamic Island occasionally fail to redraw mid-track; only recovers at the next track change or by foregrounding the app
I'm seeing an intermittent split between how different Now Playing surfaces reconcile with a RemoteMediaSessionExtension (the iOS 27 com.apple.nowplaying.remote-media extension point). Control Center and Apple Watch reliably show the current track. The Lock Screen and Dynamic Island occasionally get stuck on the previous track for the remainder of that track. They'll often self-correct once the next track change happens — but not always and never mid-track. The only way to fix it before the track ends is to bring the host app to the foreground. Setup: the extension receives APNs pushes carrying playback/metadata payloads from a third-party speaker system. Each push either resumes an already-alive extension process (update(:)) or cold-starts it (session(:)), which sets content/the Artwork provider closure and returns. All three surfaces read from that exact same synchronous content value — there is no code path in the extension that could serve them differently. Cleanest isolated repro on record (device log timestamps): one track was displaying correctly everywhere. The next track triggered a cold start; the extension decoded the push, resolved and prefetched real artwork, and had content fully populated within under a second. Moments later, that cached artwork was requested and served at Control Center's own request sizes, and Control Center updated correctly. Lock Screen and Dynamic Island made zero requests of any kind — no content query, no artwork fetch — for the entire remainder of that track. This doesn’t appear to be a problem with the apns pushes, I can see from my server that they are successfully sent and Control Center updates correctly but lockscreen and Dynamic Island do not. I tried reducing the artwork size as a test to see if this worked more reliably, but still faced similar issues. Apple Watch remains a consistently-correct surface alongside Control Center, reinforcing that this is isolated to whatever presentation machinery Lock Screen and Dynamic Island specifically share. Ruled out on my side: • Push delivery/decoding — the extension's own receive-time debug dump shows the correct decoded attributes before any surface renders. • Process suspension — this has been observed with the extension actively running throughout, proven by Control Center rendering fresh data from it during the same window. Questions: Is there a known issue where Lock Screen/Dynamic Island stop re-querying a RemoteMediaSessionExtension's content mid-track, after it's already been correctly delivered and rendered elsewhere (Control Center, Watch)? Is Lock Screen/Dynamic Island's own redraw path gated on the app process being foreground, similar to requestToBecomeSystemPrimary()'s documented foreground-only effect? If so, is there any supported way to trigger that reconciliation from a background extension update, short of the user opening the app? Is there a supported way to force-invalidate/redraw Lock Screen's and Dynamic Island's cached presentation for an existing session, without ending and restarting it (which would reset the user's Lock Screen state)?
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Using MusicKit to display a user’s currently playing Apple Music track
Hello, I’m evaluating a possible MusicKit integration and would like to clarify whether the following use is permitted. With the user’s explicit and revocable consent, our iOS app would read the song currently playing in Apple Music while our app is active and display the song title and artist to other users of our application. Our app would not play, stream, host, download or redistribute Apple Music audio. Music playback would remain entirely within Apple Music. When our app is closed, it would stop accessing Apple Music. The last synchronized song may remain displayed until the user opens our app again, at which point the currently playing song would be refreshed. If a displayed song is tapped, the user would be redirected to Apple Music. We are happy to follow Apple’s required formatting, attribution and linking rules. Album artwork is not required and can be omitted if necessary. The Apple Music functionality itself would remain free. Any monetization would relate only to separate features of the application. Could someone clarify: Is this use permitted under the MusicKit / Apple Music requirements? May the current song title and artist be displayed to other users in this way? Which official Apple framework/API is recommended for detecting the song currently playing in Apple Music while our app is active? Are there specific attribution or linking requirements for this use? Thank you.
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Picture-In-Picture not starting with Custom Player
Team, I am trying to start PictureInPicture for my video from custom player as mentioned in the following link, but I am getting an error Steps: Created a player using AVPlayer. Initiated AVPictureInPictureController with AVPlayerLayer Added observer on PIP button enable status When PIP button is tapped executed pipController.startPictureInPicture() statement. PIP is not getting started & getting following error Project created in Xcode11 & currently using Xcode13.2 Error Domain=AVKitErrorDomain Code=-1001 "Failed to start picture in picture." UserInfo={NSLocalizedDescription=Failed to start picture in picture., NSLocalizedFailureReason=The UIScene for the content source has an activation state other than UISceneActivationStateForegroundActive, which is not allowed.} I didn't get any solutions online, plz help me on this issue. FYI: PIP button/mode is working if I use AVPlayerViewController(with default playerItem buttons) instead of AVPlayer & AVPictureInPictureController with custom controls Thanks in advance. Adopting Picture in Picture in a Custom Player
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3d
macOS 27 regression: HDMI + DisplayPort Multi-Output audio fails with Core Audio error 1937010544
Hi, I believe I have found a Core Audio regression in macOS 27. This exact hardware configuration worked correctly on macOS 26, and the issue started immediately after upgrading to macOS 27. Hardware: Mac mini M2 2 × MSI MP243X monitors Monitor 1 connected via HDMI Monitor 2 connected via DisplayPort Both monitors expose a 2-channel audio output to macOS On macOS 26: I used Audio MIDI Setup to create a Multi-Output Device containing both MSI MP243X audio outputs. Audio played simultaneously through both monitors without any issues. On macOS 27: Both audio devices are still detected correctly and both work perfectly when selected individually: HDMI only: WORKS DisplayPort only: WORKS HDMI + DisplayPort simultaneously: FAILS This is reproducible even immediately after a full reboot. When I create a new Multi-Output Device containing both MSI outputs and select it as the system output, audio playback cannot start. For example: afplay /System/Library/Sounds/Glass.aiff returns: Error: AudioQueueStart failed ('stop') I captured Core Audio debug logs while reproducing the problem. Core Audio initially reports that StartIO succeeded, but the physical display audio device then fails to establish a timeline. Relevant log messages include: HALS_IOEngine2::_StartIO succeeded Device 3669B540-0000-0000-2623-0104A5351D78 is not running. could not establish a timeline after waiting 10000000 microseconds stopping with error 1937010544 StartIOThread: the IO thread failed to start, Error: 1937010544 I have already tested the following: Both devices at 44.1 kHz / 24-bit Both devices at 48 kHz / 16-bit Recreating the Multi-Output Device from scratch Using the HDMI device as clock source Using the DisplayPort device as clock source Different drift correction configurations Restarting coreaudiod Full macOS reboot Testing both outputs individually immediately after reboot Alternative multi-device audio routing software The behavior is always reproducible. Each MSI MP243X audio endpoint works correctly by itself. The failure only occurs when both HDMI and DisplayPort audio endpoints are opened simultaneously. system_profiler correctly detects both devices at 48 kHz: MSI MP243X Output Channels: 2 Current Sample Rate: 48000 Transport: HDMI MSI MP243X Output Channels: 2 Current Sample Rate: 48000 Transport: DisplayPort This does not appear to be a problem with either monitor or connection individually, because both outputs continue to work independently. The important difference is the macOS version: macOS 26: HDMI + DisplayPort Multi-Output = WORKING macOS 27: HDMI only = WORKING DisplayPort only = WORKING HDMI + DisplayPort Multi-Output = FAILS with AudioQueueStart 'stop' / Core Audio error 1937010544 No hardware, monitor, cable, or connection changes were made between the working macOS 26 configuration and the macOS 27 configuration. This therefore appears to be a regression in the Core Audio/display-audio path introduced with macOS 27 when two display audio endpoints (HDMI + DisplayPort) are opened simultaneously. Has anyone else been able to reproduce this on macOS 27, particularly on Apple Silicon? I can provide the complete coreaudiod logs and run additional Core Audio diagnostics if needed. Additional isolation tests: Both monitors can remain physically connected to the Mac at the same time. With both HDMI and DisplayPort connected: Selecting the HDMI MSI MP243X as the only output works correctly. Selecting the DisplayPort MSI MP243X as the only output works correctly. Opening both audio endpoints simultaneously causes the failure. Therefore, simply having both displays connected does not trigger the issue. The failure appears specifically when Core Audio attempts to run both display-audio endpoints at the same time. I also tested this using third-party multi-device audio routing implementations instead of relying only on Audio MIDI Setup. The same behavior occurs: either MSI MP243X can be opened and used independently, but attempting to route audio to both devices simultaneously fails. This suggests that the issue is below the Multi-Output Device configuration itself and may be related to starting/synchronizing two display-audio IO engines simultaneously. During the failure, the Core Audio log sequence is particularly interesting: The physical device is detected normally. The audio format is configured successfully. Core Audio reports that StartIO succeeded. The device subsequently reports that it is not running. Core Audio waits 10 seconds for a timeline. Timeline establishment fails. The IO thread terminates with error 1937010544 ('stop'). One captured conversion path was: 2 ch, 48000 Hz, Float32, interleaved -> 2 ch, 48000 Hz, Int16, interleaved so both sides were operating at 48 kHz during this test. Another important observation is that restarting coreaudiod does not resolve the simultaneous-output problem. A complete reboot also does not resolve it: immediately after a fresh boot, before launching any third-party audio-routing software, both physical outputs work individually but a newly created Multi-Output Device still reproduces the failure. This makes the issue highly reproducible on this machine. Minimal reproduction: Boot macOS 27 with both MSI MP243X monitors connected. Open Audio MIDI Setup. Verify both MSI MP243X devices work independently. Set both devices to 48,000 Hz. Create a new Multi-Output Device. Select both MSI MP243X devices. Select the new Multi-Output Device as the system audio output. Run: afplay /System/Library/Sounds/Glass.aiff Expected result: The sound is reproduced simultaneously through both monitors, as it was on macOS 26. Actual result: Error: AudioQueueStart failed ('stop') Switching the system output back to either individual MSI MP243X restores audio playback. The problem can then be reproduced again by selecting the Multi-Output Device.
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3d
MusicKit API — Compatibility question regarding user-initiated scoring method
Hi everyone, I'm building Sidetick, a concert ticketing and cultural discovery platform. I have an active Apple Developer Program account with MusicKit access. I want to implement the following flow and need to know if it complies with the MusicKit License Agreement: User authenticates via MusicKit (explicit OAuth consent) We read their heavy-rotation and library/artists in memory We calculate a fan affinity score per artist (e.g. "480 XP with Angèle") — entirely in-memory, never written to our DB We show the user: "We found these artists — which ones do you want to follow on Sidetick?" User explicitly picks their favorites ALL Apple Music API data is immediately deleted from our systems What we store is only the user's Sidetick declaration: {artist: "Angèle", xp: 480} — no Apple Music raw data retained After this, ALL gamification (fan ranking, ticket priority, rewards) is based exclusively on Sidetick first-party actions (ticket purchases, attended concerts, referrals) — zero Apple Music data involved. The intent: MusicKit is used as a one-time discovery bootstrap to help users identify which artists to follow on Sidetick. Apple Music data is never stored, never shared with third parties, never used for advertising. My questions: Is this use case compatible with the MusicKit License Agreement? Is storing the calculated XP score (after deleting the source Apple Music data) considered retaining Apple Music data? Is there a specific clause we should be careful about? Thanks in advance — any Apple engineer or experienced MusicKit dev input is very welcome. =D
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fail to get HLS realtime stream via AVPlayerItemSampleBufferOutputDelegate
Hi, I'm trying to do some realtime audio processing on audio served from an HLS stream (i.e. an AVPlayer created using an M3U HTTP URL). And I find that new APIs(AVPlayerItemSampleBufferOutput) are available in iOS 27.0 to achieve it. However, I failed to get the available data via the AVPlayerItemSampleBufferOutputDelegate. And I found some error in the system log: I create AVPlayerItemSampleBufferOutput and set the delegate after receiving the AVPlayerItemStatusReadyToPlay event. And here's my code: @interface OCAudioSamplebuffer () <AVPlayerItemSampleBufferOutputDelegate> @property (nonatomic, strong) AVPlayerItemSampleBufferOutput *bufferOutput; @property (nonatomic, strong) dispatch_queue_t bufferOutputQueue; @property (nonatomic, strong) AVPlayerItem *playerItem; @end - (void)playItem:(AVPlayerItem *)item { if (@available(iOS 27, *)) { AVAudioSession *audioSession = [AVAudioSession sharedInstance]; if([NSThread mainThread]){ [audioSession setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryPlayback error:nil]; [audioSession setActive:YES error:nil]; }else{ dispatch_async(dispatch_get_main_queue(), ^{ [audioSession setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryPlayback error:nil]; [audioSession setActive:YES error:nil]; }); } AVPlayerItemSampleBufferOutputAudioConfiguration *cfg = [[AVPlayerItemSampleBufferOutputAudioConfiguration alloc] init]; CMFormatDescriptionRef formatDescription = [self createPCMFormatDescriptionWithSampleRate:44100.0 channels:2 isFloat:YES]; cfg.requestedAudioFormat = formatDescription; if (formatDescription) { NSLog(@"create PCM Format Description success"); CFRelease(formatDescription); } else { NSLog(@"fail to create PCM Format Description"); } self.bufferOutput = [[AVPlayerItemSampleBufferOutput alloc] initWithConfiguration:cfg]; NSLog(@"create buffer success, PCM Format Description%@---,%@", cfg.requestedAudioFormat, formatDescription); self.bufferOutputQueue = dispatch_queue_create("audioSamplebufferQueue", DISPATCH_QUEUE_CONCURRENT); [self.bufferOutput setDelegate:self queue:self.bufferOutputQueue]; [item addOutput:self.bufferOutput]; self.playerItem = item; } else { // Fallback on earlier versions } } Any help. Thank you
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5d
Tracks missing from Apple Music API listening history
I have a product that relies on the Apple Music API's "recently played tracks" endpoint. Recently, a few users are reporting that there are songs missing from their history. I was able to observe this myself—the issue corrected itself after re-authenticating with Apple Music, but unfortunately for at least one user this is not helping in their case. What's odd is that there is some inconsistency about what shows in the recently played tracks endpoint. Some examples My own account: ✅ Music from my playlists ✅ Albums and singles ✅ Apple editorial playlists ❌ Playlists created by other users User 1: ❌ Music from their playlists ✅ Albums and singles ❌ Apple editorial playlists ❌ Playlists created by other users In most cases, all four of these would appear in the recent tracks API. What could cause these tracks to be missing from the listening history endpoint? Listening history is already enabled for the devices they're using, but the songs are appearing inconsistently.
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5d
Push-to-start RemoteMediaSession never appears on Lock Screen/Control Center without opening the app — expected behavior?
I'm implementing the new NowPlaying framework's remote-session push-to-start flow (per Publishing remote media sessions) to show a Sonos-like remote speaker's playback on the Lock Screen/Control Center without requiring my app to be running. The docs say: Your server can start, update, or end sessions when your app isn't running. Use this approach when playback starts from a remote device without someone opening your app. That section never mentions requestToBecomeSystemPrimary() — that's only documented under "Start and update sessions from your app," with a note that it's a no-op unless the app is foregrounded. In my testing, though, a session created purely via a push-to-start "event":"start" push never shows up anywhere in system UI (not Control Center, not the Lock Screen) until I open the app at least once. The mechanism itself works correctly — RemoteMediaSessionExtension.session(_:) fires reliably, decodes the attributes correctly, and returns a valid RemoteMediaSessionRepresentable (confirmed via on-device logging: no errors, clean construction every time, across dozens of test pushes). It just isn't surfaced. To rule out anything on my end, I've tested: Sending via my own server (correct apns-topic/apns-push-type headers, confirmed working via HTTP/2 200 and correct decode) Sending via the Push Notifications Console directly, with Environment explicitly set to Production (my push-to-start token only validates against production, matching the known dev-signed-token-provisions-against-production quirk) A hand-built, minimal, fully valid payload for a completely fresh, never-before-registered session id Every combination produces a correctly-constructed session that's invisible until the app opens — at which point my own app code (unrelated to the push) independently constructs and promotes its own session via RemoteMediaSession.start() + requestToBecomeSystemPrimary() in the foreground. Has anyone gotten a push-to-start session to actually appear on the Lock Screen/Control Center without opening the app first? Is there an additional step beyond what's in the current docs (some other registration, entitlement, or timing requirement) that's needed for that, or is this expected behavior right now and the docs are ahead of the implementation? FB24876585 filed on Feedback Assistant with app logs attached.
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5d
Music.app hangs on Library tab with Sync Library enabled — iOS 27.2 beta
On iPhone 17 Pro Max running iOS 27.2 beta (24B5084k), Music.app hangs and is watchdog-terminated when opening the Library tab, but only with Sync Library enabled. to reproduce: 1. Settings › Apps › Music › Sync Library OFF — app works normally. 2. Enable Sync Library, let it finish syncing. 3. Open Music and navigate to the Library tab. Result: The app freezes immediately and is terminated. Home, Radio and Search all play normally with Sync Library on — the hang is isolated to the Library tab. The stackshot from Analytics Data shows multiple threads blocked on a single thread, including com.apple.SwiftUI.AsyncRenderer, with the watchdog reporting "Failed to terminate gracefully after 5.0s". No VPN, no automatic downloads, no local files. The same Apple Music account works normally on iPadOS 26 and on Apple Music for Windows. 100% reproducible. Filed as FB24865181. Has anyone else hit this? If so, does your Music- analytics log show the same blocked-thread signature?
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6d
AVSpeechSynthesizer does not work on "Mac (Designed for iPad)", with some voices
The iOS 26 sample below speaks well on iPhone/iPad devices and the iOS simulator. But it does not speak on "Mac (Designed for iPad)", with a voice downloaded via the macOS settings. Instead it issues this warning : Invalid maui voice identifier com.apple.voice.enhanced.en-US.Samantha How to make an iOS app speak on "Mac (Designed for iPad)", with a downloaded voice ? Note : I use iOS 26.5.2 and macOS 26.5.2. I use voices that can be found in System Settings > Accessibility > Read & Speak > System voice. I have checked that "Samantha (Enhanced)" is the "System voice" in the macOS settings. I have checked that the same issue occurs with other voices and other languages. There is no such issue for a voice that never needs to be downloaded. import AVFAudio import SwiftUI @main struct SampleApp: App { var body: some Scene { WindowGroup { SampleView() } } } struct SampleView: View { private var synthesizer = AVSpeechSynthesizer() var body: some View { Button("Speak", action: speak) } private func speak() { let utterance = AVSpeechUtterance(string: "I speak English.") utterance.voice = AVSpeechSynthesisVoice(language: "en") self.synthesizer.speak(utterance) } }
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Issues with AVRoutePickerView channel switching
We are developing a voice call application that uses AVRoutePickerView, allowing users to switch between an iPhone, a speaker, and Bluetooth earphones. However, we have encountered an intermittent issue: when switching from the speaker to Bluetooth earphones, the earphones remain in a loading state, and the audio channel subsequently switches back to the speaker. How can we resolve this issue? Here is the sample code: let session = AVAudioSession.sharedInstance() do { try session.setCategory(.playAndRecord, mode: .default, options: [.allowBluetooth]) try session.overrideOutputAudioPort(isBluetoothConnected ? .none : .speaker) try session.setPreferredSampleRate(48000) try session.setPreferredIOBufferDuration(0.02) try session.setActive(true, options: []) INFO(" >>> start: hasBluetooth=\(isBluetoothConnected), inputs: \(session.currentRoute.inputs.map { $0.portType }) outputs: \(session.currentRoute.outputs.map { $0.portType })") } catch { ERROR("(error.localizedDescription)") }
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Public API availability for AirPods custom EQ in iOS 27
Hi, Is there a public API in iOS 27 to read or modify the Low, Mid, and High values of the AirPods custom EQ shown in Settings? Specifically, I’m asking about the device-level EQ on AirPods Pro, rather than in-app audio processing using AVAudioUnitEQ. If no public API is available, is there a system-provided Shortcuts action or another officially supported way to access these settings? Thank you.
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Signaling Mach semaphores from an IOProc
What is the official stance on the safety of signaling Mach semaphores from within a Core Audio real-time context? The most recent guidance I can find says: To ensure glitch-free performance, audio processing must occur in a real-time safe context. Don’t allocate memory, perform file I/O, take locks, or interact with the Swift or Objective-C runtimes when rendering audio. Mach semaphores have internal synchronization primitives (a spinlock and perhaps others) but I also believe that the scheduling priority level is elevated internally to prevent priority inversion. So while it seems that Mach semaphores could be prohibited I wonder if that is truly the case here. So while a call to semaphore_signal does involve locks, in a Core Audio real-time context, is it safe?
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iOS 27 Public Beta 6: CallKit UI remains after ending two outgoing calls in modified Apple Speakerbox sample
Summary On an iPhone 17 running iOS 27 Public Beta 6, the system CallKit UI remains visible after ending two outgoing calls individually. This is reproducible using Apple's “Making and Receiving VoIP Calls with CallKit” sample (Speakerbox), with only two minimal changes to support multiple simultaneous calls. After both calls end, Speakerbox displays “No Calls”, but the system CallKit UI still shows 111, and the Dynamic Island retains a call-related status. Environment Device: iPhone 17 (physical device) OS: iOS 27 Public Beta 6 App: Apple's Speakerbox sample with the modifications below Backend: None. The sample's original simulated calls are used; no external VoIP SDK is involved. Changes to the original sample Only two files were modified. 1. ProviderDelegate.swift Added: providerConfiguration.maximumCallGroups = 3 The original setting remains unchanged: providerConfiguration.maximumCallsPerCallGroup = 1 2. SpeakerboxCallManager.swift Before starting a new outgoing call, hold existing calls that are not already on hold. The hold actions and new start action are submitted in the same transaction: let transaction = CXTransaction() for call in calls where !call.isOnHold { transaction.addAction( CXSetHeldCallAction(call: call.uuid, onHold: true) ) } transaction.addAction(startCallAction) requestTransaction(transaction) No changes were made to the simulated connection timing, startedConnectingAt/connectedAt reporting, CXEndCallAction handling, call removal, or audio handling. The original end-call handler finds the call by UUID, calls endSpeakerboxCall(), fulfills the end action, and removes the call from the app's list. Steps to reproduce Launch the modified Speakerbox sample. Create an outgoing call to 111. Create a second outgoing call to 222. The first call is placed on hold. Wait until Speakerbox shows 111 — On Hold and 222 — Active, with call durations displayed. In Speakerbox, select 222 - End Call. Select 111 - End Call. Confirm that Speakerbox displays “No Calls”. Open the app switcher and inspect the system CallKit UI. Also inspect the Dynamic Island. Open the remaining system call UI and tap End. Expected result After both calls end, the system should no longer display an ongoing call in the CallKit UI or Dynamic Island. Actual result Speakerbox displays “No Calls”. The system CallKit UI continues to display the first call, 111. The Dynamic Island continues to show a call-related “Hold” status. Tapping End in the remaining system call UI does not clear the residual state during the recording. The issue occurs even after waiting for both simulated calls to connect before ending them. This is the system-provided CallKit UI, not an active-call view implemented by the sample app. Reproduction video Recording: 4b03d30e507b874d9c19c0523632e9d6.mp4 00:24–00:26 (approximately): Both calls are present; 111 is on hold and 222 is active. 00:26–00:31 (approximately): End 222, then end 111. Speakerbox displays “No Calls”. 00:31–01:03 (approximately): The system CallKit UI and Dynamic Island retain the call state despite further attempts to end it. Questions Is this an iOS 27 regression, or is additional lifecycle handling required when extending Speakerbox to support multiple calls? Please advise what additional diagnostics would help investigate why the system UI retains an ongoing-call state after both calls have been ended using the sample's original end-call handling. Source and video downloads https://github.com/willbin/callkit-ios27-repro/releases/tag/repro-v1
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AirPods audio repeatedly cuts out under CPU and memory pressure on M5 Max MacBook Pro
I filed FB24725256 with a live macOS Bluetooth diagnostic, Sysdiagnose, and System Information Report. Environment: MacBook Pro (Mac17,6), Apple M5 Max, 128 GB RAM macOS 26.5 (25F71) AirPods Pro 3, firmware 8B41 AirPods selected for both input and output because microphone input is required for dictation and voice typing Problem: Bluetooth playback repeatedly stutters and cuts out during sustained local development and AI-agent workloads. The AirPods signal is strong (roughly -46 to -52 RSSI), and the Mac remains otherwise usable. Unified logs recorded repeated AudioSkywalkReadLoop overwait events in bluetoothd, commonly 50–69 ms and previously up to 795 ms. CoreAudio also reported HALS_OverloadMessage failures because a client exceeded its I/O-cycle budget and a safety violation occurred. Steps to reproduce: Connect AirPods Pro and keep them selected for input and output. Stream audio. Run sustained CPU- and memory-intensive development work, such as multiple builds, browser workloads, simulators, or local AI agents. Observe repeated playback interruptions as CPU load and memory compression increase. Expected: macOS should protect real-time CoreAudio and Bluetooth transport deadlines on this hardware without requiring productive work to be paused or throttled. The same AirPods stream reliably from much smaller Apple devices; Apple's highest-end Mac should maintain audio continuity too. This is a platform-quality failure on a high-end Mac. This appears related to longstanding reports: Simulator/Xcode causing AirPods distortion: https://developer.apple.com/forums/thread/668170 CoreAudio overloads and dropouts associated with memory pressure: https://developer.apple.com/forums/thread/677383 Bluetooth headset interruptions on newer macOS releases: https://developer.apple.com/forums/thread/763848 If you can reproduce this, please boost this thread and file your own Feedback Assistant report with fresh Bluetooth logs and a Sysdiagnose. Include the exact occurrence time and reference FB24725256 so Apple can connect the reports.I filed FB24725256 with a live macOS Bluetooth diagnostic, Sysdiagnose, and System Information Report. Environment: MacBook Pro (Mac17,6), Apple M5 Max, 128 GB RAM macOS 26.5 (25F71) AirPods Pro 3, firmware 8B41 AirPods selected for both input and output because microphone input is required for dictation and voice typing Problem: Bluetooth playback repeatedly stutters and cuts out during sustained local development and AI-agent workloads. The AirPods signal is strong (roughly -46 to -52 RSSI), and the Mac remains otherwise usable. Unified logs recorded repeated AudioSkywalkReadLoop overwait events in bluetoothd, commonly 50–69 ms and previously up to 795 ms. CoreAudio also reported HALS_OverloadMessage failures because a client exceeded its I/O-cycle budget and a safety violation occurred. Steps to reproduce: Connect AirPods Pro and keep them selected for input and output. Stream audio. Run sustained CPU- and memory-intensive development work, such as multiple builds, browser workloads, simulators, or local AI agents. Observe repeated playback interruptions as CPU load and memory compression increase. Expected: macOS should protect real-time CoreAudio and Bluetooth transport deadlines on this hardware without requiring productive work to be paused or throttled. The same AirPods stream reliably from much smaller Apple devices; Apple's highest-end Mac should maintain audio continuity too. This is a platform-quality failure on a high-end Mac. This appears related to longstanding reports: Simulator/Xcode causing AirPods distortion: https://developer.apple.com/forums/thread/668170 CoreAudio overloads and dropouts associated with memory pressure: https://developer.apple.com/forums/thread/677383 Bluetooth headset interruptions on newer macOS releases: https://developer.apple.com/forums/thread/763848 If you can reproduce this, please boost this thread and file your own Feedback Assistant report with fresh Bluetooth logs and a Sysdiagnose. Include the exact occurrence time and reference FB24725256 so Apple can connect the reports.
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AirPlay fails when Mac is connected to iPhone Personal Hotspot
AirPlay fails when Mac is connected to iPhone Personal Hotspot I’m using AVRoutePickerView to route audio from an iPhone app to a Mac with AirPlay Receiver enabled. What works When the iPhone and Mac are connected to the same Wi-Fi network, AirPlay routing works normally. Routing audio back to the iPhone speaker or to connected AirPods over Bluetooth also works correctly. What fails When the iPhone provides a Personal Hotspot and the Mac connects to that iPhone’s hotspot, the Mac still appears as an available destination in AVRoutePickerView. However, selecting the Mac fails with: Unable to connect to “[Mac Name]” Questions Is AirPlay routing from an iPhone hosting a Personal Hotspot to a Mac connected to that hotspot a supported network topology? If it is supported, are there any additional AVAudioSession, networking, entitlement, or AirPlay configuration requirements for this scenario? The fact that the Mac is successfully discovered and displayed by AVRoutePickerView, but the connection itself fails, is the part I’m particularly trying to understand. Thank you for any guidance on the expected behavior here.
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RemoteMediaSession started while the app is in the background no longer appears in Control Center (worked in earlier betas)
My app publishes a NowPlaying.RemoteMediaSession for music playing on speakers on the local network. While the app is in the background and someone taps play on my widget, that intent runs in my app process and wakes the app in the background — it can fetch the speaker state and start and update the remote session without any trouble. As of Beta 6, the session is created successfully but never shows up in Control Center or on the Lock Screen. It only appears the moment I bring my app to the foreground. In earlier betas the same code showed the session in control center, without needing to open the app. I don't call requestToBecomeSystemPrimary() and I don’t expect it to be set as primary, only when my app is in the foreground but at least the session should appear in control center or the lock screen as an option for the user to set it to system primary. FB24439526 has been submitted with Sysdiagnose attached.
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Supported MusicKit APIs for vinyl-style speed, pitch and reverse playback of subscription songs on iOS?
I am building a personal iPhone prototype with an on-screen record platter. Before enrolling in the Apple Developer Program or developing the Apple Music integration further, I would like to establish whether the core interaction is supported by public APIs. The intended interaction is: Tap the platter to play or pause an Apple Music subscription song. Hold the platter to stop playback at its current position. Move the platter forward or backward to control the direction and speed of audible playback continuously. Change pitch together with speed, like a physical record, rather than preserving the original pitch. Release the platter to smoothly return to normal playback. Hold a separate control to listen continuously at a faster speed. A prototype using an AVAudioEngine-based renderer works with unprotected local audio. I have NOT verified these behaviors with Apple Music subscription content. I understand that this local renderer does not establish feasibility for MusicKit, and I am not seeking to extract protected audio or bypass content protection. MusicPlayer.State.playbackRate is documented as settable, with positive values for forward playback and negative values for reverse playback: https://developer.apple.com/documentation/musickit/musicplayer/state-swift.class/playbackrate For ApplicationMusicPlayer on iOS, is this vinyl-style interaction supported for full Apple Music subscription songs, rather than previews or user-owned unprotected files? In particular: What playback-rate range is supported for subscription songs? Do negative rates produce audible reverse playback, and how should zero-speed holding be implemented? Is there a documented public API to make pitch follow playback speed, or to disable pitch preservation? Are frequent rate and direction changes supported for interactive scratching? Are there documented limitations on update frequency, buffering, seeking precision or responsiveness? If this interaction is outside public MusicKit capabilities, is there an official channel where an individual developer can ask about eligibility for an approved Apple Music DJ integration? I am asking for the supported API path and its limitations, not implementation details of another app. If only ordinary variable-speed playback or seeking is supported, a clear distinction from continuous vinyl-style scratching would be very helpful. The initial goal is personal use; possible App Store distribution is undecided. I have an active Apple Music subscription but am not currently enrolled in the paid Apple Developer Program. Thank you.
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Building a library playlist on macOS that mixes catalog songs and the user's own uploads in a fixed order – supported route, and how to know when an upload is registered?
Our sandboxed macOS app digitises audio cassettes and builds one playlist per cassette in the user's Apple Music library that follows the tape's order: catalog songs where a title was recognised, and the user's own recordings (AAC files the app exported from the tape) where it was not. The user has an Apple Music subscription and Sync Library on. On macOS every write on MusicLibrary is marked @available(macOS, unavailable) in the 26.5 SDK – add, add(_:to:), createPlaylist and edit (see thread 844114, which got no answer). So we build the playlist through Music.app's scripting interface: make new user playlist, duplicate <library track> to <playlist> for catalog songs, add <file> to <playlist> for own recordings. That works, with one exception that leads to our questions. What we observe Reproducible on macOS 26.6.2 / Music 26; a standalone AppleScript is at the end. A playlist built in one go from 14 subscription tracks keeps all 14. The same playlist with one local file added after the second track: all 15 entries are there right after the build and one second later. About 15 s later the playlist has 3 entries – the two catalog entries before the file, the file, and nothing that was added after it. No error anywhere. If the file has been in the library for several minutes before the playlist is built, everything stays. Adding it to the library and waiting 45 s is not enough. Meanwhile the track's cloud status stays unknown, and GET /v1/me/library/search?types=library-songs does not list it (checked for 10 minutes). Emptying the playlist and building it again ~30 s after the entries were removed keeps everything, every time. That is what we do today; it costs 30–40 s per import, and we have to tell the user that entries were removed and put back. Our reading: while the freshly added file is not yet registered in iCloud Music Library, the playlist as pushed to the server is cut at the first item the server cannot reference, and the next sync adopts the shorter list for cloud items while keeping the local-only item in place. Questions Is there a supported way for a macOS app to create a library playlist and add tracks to it? Specifically: is the Apple Music API (POST /v1/me/library/playlists with relationships.tracks, and POST /v1/me/library/playlists/{id}/tracks) the intended route from a macOS app holding a MusicKit user token, and can such a playlist reference the user's own uploaded songs by their library id (i.…)? After a local file has been added to the library (via Music.app's add, or any other supported way), how can an app learn that iCloud Music Library has registered it, and what its library song id is? A notification, a MusicKit property, an Apple Music API endpoint? We would wait on that signal instead of rebuilding. Is the removal described above expected behaviour? Catalog ids are re-resolved at import time via id, ISRC and search as recommended in thread 122110, so stale catalog ids are not the cause. Reproduction Needs Sync Library on, at least 14 subscription tracks in the library, and a local audio file the library does not know yet. Prints the counts after 1 s, 21 s and 41 s, then cleans up. on run argv set localFile to POSIX file (item 1 of argv) tell application "Music" set cloudTracks to (every track of library playlist 1 whose cloud status is subscription) set idsBefore to persistent ID of every track of library playlist 1 set pl to make new user playlist with properties {name:"Reconciliation repro"} repeat with i from 1 to 2 duplicate (item i of cloudTracks) to pl end repeat set fileTrack to add localFile to pl set fileID to persistent ID of fileTrack repeat with i from 3 to 14 duplicate (item i of cloudTracks) to pl end repeat set n0 to count of tracks of pl delay 1 set n1 to count of tracks of pl delay 20 set n2 to count of tracks of pl delay 20 set n3 to count of tracks of pl delete pl if fileID is not in idsBefore then delete (first track of library playlist 1 whose persistent ID is fileID) return "after build: " & n0 & ", after 1 s: " & n1 & ", after 21 s: " & n2 & ", after 41 s: " & n3 end tell end run Output here: after build: 15, after 1 s: 15, after 21 s: 3, after 41 s: 3.
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visionOS Developer Strap: UVC video works, but how can I access the capture device’s USB Audio Class (UAC) audio?
I’m developing a native visionOS application that uses an external HDMI capture device connected to Apple Vision Pro through the Developer Strap. The goal is to use Apple Vision Pro as a low-latency display for external HDMI sources such as an Xbox Series X, including both the HDMI video and the original digital game audio. My current hardware path is: Xbox Series X → HDMI → Elgato 4K X → USB-C → Apple Vision Pro Developer Strap The Elgato 4K X receives both video and audio from the Xbox over HDMI. What is working UVC video capture is working successfully on visionOS. The external Elgato capture device can be used as the video source and the Xbox video is displayed correctly inside the Vision Pro application. I have also verified the Elgato 4K X independently on macOS, where the device is recognized correctly. The problem I cannot find a supported way on visionOS to access the USB Audio Class (UAC) audio interface associated with the capture device. I specifically need the digital game audio originating from: Xbox HDMI → Elgato 4K X → USB/UAC → visionOS I do not want to use the Apple Vision Pro’s built-in microphone. Selecting/capturing the Vision Pro microphone would only record environmental sound and is not a substitute for the digital HDMI audio stream. Apple’s visionOS documentation for external devices through the Developer Strap appears to focus on UVC video capture. I haven’t been able to determine whether the accompanying UAC interface of a UVC/UAC composite capture device is exposed to visionOS applications. What I’ve tried / verified Connected an Xbox Series X to the HDMI input of an Elgato 4K X. Connected the 4K X to Apple Vision Pro through the Developer Strap. Successfully discovered and received the external UVC video stream. Successfully displayed the Xbox video feed in visionOS. Confirmed that the 4K X itself is recognized and functional on macOS. Attempted to obtain audio corresponding to the external capture source. The Vision Pro microphone is available as an audio source, but this is not the audio source required. I have not found a documented visionOS API that exposes the 4K X’s USB/UAC audio endpoint through the Developer Strap. Questions Does visionOS currently support USB Audio Class input devices connected through the Apple Vision Pro Developer Strap? If a device exposes both UVC video and UAC audio interfaces, is there a supported way to associate/access both interfaces from a visionOS application? If UAC is supported, which framework/API should be used to discover the external audio endpoint — AVFoundation, Core Audio, or another API? Does accessing the UAC interface require an entitlement in addition to UVC device access? If generic UAC access through the Developer Strap is currently unavailable to third-party visionOS applications, is there a restricted/managed entitlement that developers can request? If this isn’t currently supported, what is Apple’s recommended architecture for receiving synchronized video and audio from an HDMI capture device on Apple Vision Pro? Ultimately, I’m trying to achieve: HDMI source → UVC video + UAC audio → visionOS application → video displayed in Vision Pro + audio played through Vision Pro speakers/AirPods Since UVC video from this exact hardware is already working, I’m primarily trying to determine whether access to the accompanying USB audio interface is possible with the current visionOS SDK, requires another entitlement/API, or is currently unsupported. Any guidance from Apple or developers who have worked with composite UVC/UAC devices on Vision Pro would be greatly appreciated.
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