According to the header file the outputVolume properties supported range is 0.0-1.0:
/*! @property outputVolume
@abstract The mixer's output volume.
@discussion
This accesses the mixer's output volume (0.0-1.0, inclusive).
@property (nonatomic) float outputVolume;
However when setting the volume to 2.0 the audio does indeed play louder. Is the header file out of date and if so, what is the supported range for outputVolume?
Thanks
Audio
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Title: Unable to Access Microphone in Control Center Widget – Is It Possible?
Hello everyone,
I'm attempting to create a widget in the Control Center that accesses the microphone, similar to how Shazam does it. However, I'm running into an issue where the widget always prints "Microphone permission denied." It's worth mentioning that microphone access works fine when I'm using the app itself.
Here's the code I'm using in the widget:
swift
Copy code
func startRecording() async {
logger.info("Starting recording...")
print("Starting recording...")
recognizedText = ""
isFinishingRecognition = false
// First, check speech recognition authorization
let speechAuthStatus = await withCheckedContinuation { continuation in
SFSpeechRecognizer.requestAuthorization { status in
continuation.resume(returning: status)
}
}
guard speechAuthStatus == .authorized else {
logger.error("Speech recognition not authorized")
return
}
// Then, request microphone permission using our manager
let micPermission = await AudioSessionManager.shared.requestMicrophonePermission()
guard micPermission else {
logger.error("Microphone permission denied")
print("Microphone permission denied")
return
}
// Continue with recording...
}
Issues:
The code consistently prints "Microphone permission denied" when run from the widget.
Microphone access works without issues when the same code is executed from within the app.
Questions:
Is it possible for a Control Center widget to access the microphone?
If yes, what might be causing the "Microphone permission denied" error in the widget?
Are there additional permissions or configurations required to enable microphone access in a widget?
Any insights or suggestions would be greatly appreciated!
Thank you.
I am trying to use SpeechTranscriber from Speech framework. Is it possible to use it on Simulator of iOS 26 (Mac OS Tahoe)? Function "supportedLocales" returns an empty array.
Hi,
May I ask if there is any API or similar way inside the iOS app to set up/switch the transparency and ANC modes of the AirPods Pro 2? One way is to set up one shortcut and activate that shortcut in the app, but it requires manually setting for a shortcut, which is not convenient.
Thx for any advice on that!
I'm trying to load Music Kit on the server with solid js. I can confirm that my implementation has been sufficient to return authentication tokens and for MusicKit.isAuthorized to return true. My issue is that if I reload the page, it only succeeds intermittently (perhaps 25% of the time?). My question is - what is wrong with my implementation? Removing the async keyword ensures it loads every time but playing and queuing music no longer works. I'm currently assuming this is an SSR issue but the docs haven't explicitly specified this isn't possible.
I have the following boilerplate:
export default createHandler(
() => (
<StartServer
document={({ assets, children, scripts }) => {
return (
<html lang="en">
<head>
<meta name="apple-music-developer-token" content={authResult.token} />
<meta name="apple-music-app-name" content="app name" />
<meta name="apple-music-app-build" content="1978.4.1" />
{assets}
<script
src="https://js-cdn.music.apple.com/musickit/v3/musickit.js"
async
/>
</head>
<body>
<div id="app">{children}</div>
{scripts}
</body>
</html>
)
}}
/>
))
When I first load my app, I'll encounter:
musickit.js:13 Uncaught TypeError: Cannot read properties of undefined (reading 'node')
at musickit.js:13:10194
at musickit.js:13:140
at musickit.js:13:209
The intermittence signals an issue relating to the async keyword. An expansion on this issue can be found here.
Hi,
May I ask if there is any iOS API or similar way to switch between the transparency and ANC modes of AirPods Pro 2? I know there is one way to configure and activate the shortcut in the APP, which requires an inconvenient manual setting. May I ask for any other advice? Thx in advance!
Is there a way to destroy MIDIUMPMutableEndpoint again?
In my app, the user has a setting to enable and disable MIDI 2.0. If MIDI 2.0 should not be supported (or if iOS version < 18), it creates a virtual destination and a virtual source. And if MIDI 2.0 should be enabled, it instead creates a MIDIUMPMutableEndpoint, which itself creates the virtual destination and source automatically.
So here is my problem: I didn't find any way to destroy the MIDIUMPMutableEndpoint again. There is a method to disable it (setEnabled:NO), but that doesn't destroy or hide the virtual destination and source. So when the user turns MIDI 2.0 support off, I will have two virtual destinations and sources, and cannot get rid of the 2.0 ones.
What is the correct way to get rid of the MIDIUMPMutableEndpoint once it is created?
I'm developing an app that plays a WAV file through the Lightning headphone adapter. When i connect the adapter, a prompt appears asking whether to select "Headphones" or "Other Device" What does this setting actually do? I've noticed that it affects the maximum amplitude (volume) of the WAV output. Could you explain the precise difference between these two modes?
Topic:
Media Technologies
SubTopic:
Audio
Environment
Windows 11 [edition/build]: [e.g., 23H2, 22631.x]
Apple Music for Windows version: [e.g., 1.x.x from Microsoft Store]
Library folder: C:\Users<user>\Music\Apple Music\Apple Music Library.musiclibrary
Summary
I need a supported way to programmatically enumerate the local Apple Music library on Windows (track file paths, playlists, etc.) for reconciliation with the on-disk Media folder. On macOS this used to be straightforward via scripting/export; on Windows I can’t find an equivalent.
What I’m seeing in the library bundle
Library.musicdb → not SQLite. First 4 bytes: 68 66 6D 61 ("hfma").
Library Preferences.musicdb → also starts with "hfma".
artwork.sqlite → SQLite but appears to be artwork cache only (no track file paths).
Extras.itdb → has SQLite format 3 header but (from a quick scan) not seeing track locations.
Genius.itdb → not a SQLite database on this machine.
What I’ve tried
Attempted to open Library.musicdb with SQLite providers → error: “file is not a database.”
Binary/string scans (ASCII, UTF-16LE/BE, null-stripped) of Library.musicdb → did not reveal file paths or obvious plist/XML/JSON blobs.
The Windows Apple Music UI doesn’t appear to expose “Export Library / Export Playlist” like legacy iTunes did, and I can’t find a public API for local library enumeration on Windows.
What I’m trying to accomplish
Read local track entries (absolute or relative paths), detect broken links, and reconcile against the Media folder. A read-only solution is fine; I do not need to modify the library.
Questions for Apple
Is the Library.musicdb file format documented anywhere, or is there a supported SDK/API to enumerate the local library on Windows?
Is there a supported export mechanism (CLI, UI, or API) on Windows Apple Music to dump the local library and/or playlists (XML/CSV/JSON)?
Is there a Windows-specific equivalent to the old iTunes COM automation or any MusicKit surface that can return local library items (not streaming catalog) and their file locations?
If none of the above exist today, is there a recommended workaround from Apple for library reconciliation on Windows (e.g., documented support for importing M3U/M3U8 to rebuild the local library from disk)?
Are there any plans/timeline for adding Windows feature parity with iTunes/Music on macOS for exporting or scripting the local library?
Why this matters
For large personal libraries, users occasionally end up with orphaned files on disk or broken links in the app. Without an export or API, it’s difficult to audit and fix at scale on Windows.
Reference details (in case it helps triage)
Library.musicdb header bytes: 68-66-6D-61-A0-00-00-00-10-26-34-00-15-00-01-00 (ASCII shows hfma…).
artwork.sqlite is readable but doesn’t contain track file paths (appears limited to artwork).
I can supply a minimal repro tool and logs if that’s helpful.
Feature request (if no current API)
Add an official Export Library/Playlists action on Windows Apple Music, or
Provide a read-only Windows API (or schema doc) that surfaces track file locations and playlist membership from the local library.
Thanks in advance for any guidance or pointers to docs I might have missed.
Hi. I am working on an audio app for iOS. I have added the CPNowPlayingPlaybackRateButton to my CPNowPlayingTemplate.
When the button is clicked, my handler changes the rate in the AVPlayer and updates the MPNowPlayingInfoCenter to the new rate, for example, 2.0.
Throughout, the Carplay button always displays "0x". I am wondering how to get this UI to accurately reflect the playback rate the user has selected, as always displaying 0x is a poor user experience.
You may suggest MPChangePlaybackRateCommand is relevant here, but I have not been able to get that to work either, and judging by posts online, not many other people have either. I have made a post about that here: https://developer.apple.com/forums/thread/773099
Is this a known Apple bug? Is there a way to get the UI to accurately reflect the playback rate of my audio?
Kind regards.
Topic:
Media Technologies
SubTopic:
Audio
Hi, I believe I've found a potential error in the sample code on the documentation page for creating and using a process tap with an aggregate device. The issue is in the section explaining how to add a tap to the aggregate device. I have already filed a Feedback Assistant ticket on this (ID: FB17411663) but haven't heard back for months.
Capturing system audio with Core Audio taps
The sample code for modifying the kAudioAggregateDevicePropertyTapList incorrectly uses the tapID as the target AudioObjectID when calling AudioObjectSetPropertyData.
// (Code to get the list and potentially modify listAsArray)
if var listAsArray = list as? [CFString] {
// ... (modification logic) ...
// Set the list back on the aggregate device. <--- The comment is correct
list = listAsArray as CFArray
_ = withUnsafeMutablePointer(to: &list) { list in
// INCORRECT: This call uses tapID as the target object.
AudioObjectSetPropertyData(tapID, &propertyAddress, 0, nil, propertySize, list)
}
}
The kAudioAggregateDevicePropertyTapList is a property that belongs to the aggregate device, not the individual tap. Therefore, to set this property, the AudioObjectSetPropertyData function must target the AudioObjectID of the aggregate device itself. Using tapID as the first argument is logically incorrect for this operation and will not update the aggregate device as intended.
Furthermore, the preceding AudioObjectGetPropertyData call to fetch the list also appears to use the incorrect tapID as its target in the sample.
The AudioObjectID for both getting and setting this property should be the ID of the aggregate device.
_ = AudioObjectGetPropertyData(aggregateDeviceID, &propertyAddress, 0, nil, &propertySize, &list)
_ = AudioObjectSetPropertyData(aggregateDeviceID, &propertyAddress, 0, nil, propertySize, newList)
Thank you!
Your draft looks great! Here's a refined version with the iOS 17 comparison emphasized and slightly better flow:
Hi Apple Engineers and fellow developers,
I'm experiencing a critical regression with ShazamKit's background operation on iOS 18. ShazamKit's SHManagedSession stops identifying songs in the background after approximately 20 seconds on iOS 18, while the exact same code works perfectly on iOS 17.
The behavior is consistent: the app works perfectly in the foreground, but when backgrounded or device is locked, it initially works for about 20 seconds then stops identifying new songs. The microphone indicator remains active suggesting audio access is maintained, but ShazamKit doesn't send identified songs in the background until you open the app again. Detection immediately resumes when bringing the app to foreground.
My technical setup uses SHManagedSession for continuous matching with background modes properly configured in Info.plist including audio mode, and Background App Refresh enabled. I've tested this on physical devices running iOS 18.0 through 18.5 with the same results across all versions. The exact same code running on iOS 17 devices works flawlessly in the background.
To reproduce: initialize SHManagedSession and start matching, begin song identification in foreground, background the app or lock device, play different songs which are initially detected for about 20 seconds, then after the timeout period new songs are no longer identified until you bring the app to foreground.
This regression has impacted my production app as users who rely on continuous background music identification are experiencing a broken feature. I submitted this as Feedback ID FB15255903 last September with no solution so far.
I've created a minimal demo project that reproduces this issue: https://github.com/tfmart/ShazamKitBackground
Has anyone else experienced this ShazamKit background regression on iOS 18? Are there any known workarounds or alternative approaches? Given the time this issue has persisted, could we please get acknowledgment of this regression, expected timeline for a fix, or any recommended workarounds?
Testing environment is Xcode 16.0+ on iOS 18.0-18.5 across multiple physical device models.
Any guidance would be greatly appreciated.
I'm working on a project to support spatial audio editing, using this sample project as a reference: https://developer.apple.com/documentation/Cinematic/editing-spatial-audio-with-an-audio-mix
This sample works well on an unedited capture, but does not work for a capture that has already been edited.
The failure is occurring at "let audioInfo = try await CNAssetSpatialAudioInfo(asset: myAsset)", which is throwing "no eligible audio tracks in asset".
I also find that for already edited captures, if i use CNAssetSpatialAudioInfo.assetContainsSpatialAudio, it returns false.
What i mean by "already edited" is that if I take a spatial capture with my iPhone 16, and then edit that capture in the Photos app using the Cinematic effect, and then save the edited output (e.g. edited_capture.mov), I can't import that edited_capture.mov into my project as a spatial audio asset.
Is this intentional behavior or a bug?
If it's intentional, can you describe why?
Topic:
Media Technologies
SubTopic:
Audio
I am trying to get MIDI output from the AU Host demo app using the recent MIDI processor example. The processor works correctly in Logic Pro, but I cannot send MIDI from the AUv3 extension in standalone mode using the default host app to another program (e.g., Ableton).
The MIDI manager, which is part of the standalone host app, works fine, and I can send MIDI using it directly—Ableton receives it without issues. I have already set the midiOutputNames in the extension, and the midiOutBlock is mapped. However, the MIDI data from the AUv3 extension does not reach Ableton in standalone mode. I suspect the issue is that midiOutBlock might never be called in the plugin, or perhaps an input to the plugin is missing, which prevents it from sending MIDI. I am currently using the default routing.
I have modified the MIDI manager such that it works well as described above. Here is a part of my code for SimplePlayEngine.swift and my MIDIManager.swift for reference:
@MainActor
@Observable
public class SimplePlayEngine {
private let midiOutBlock: AUMIDIOutputEventBlock = { sampleTime, cable, length, data in return noErr }
var scheduleMIDIEventListBlock: AUMIDIEventListBlock? = nil
public init() {
engine.attach(player)
engine.prepare()
setupMIDI()
}
private func setupMIDI() {
if !MIDIManager.shared.setupPort(midiProtocol: MIDIProtocolID._2_0, receiveBlock: { [weak self] eventList, _ in
if let scheduleMIDIEventListBlock = self?.scheduleMIDIEventListBlock {
_ = scheduleMIDIEventListBlock(AUEventSampleTimeImmediate, 0, eventList)
}
}) {
fatalError("Failed to setup Core MIDI")
}
}
func initComponent(type: String, subType: String, manufacturer: String) async -> ViewController? {
reset()
guard let component = AVAudioUnit.findComponent(type: type, subType: subType, manufacturer: manufacturer) else {
fatalError("Failed to find component with type: \(type), subtype: \(subType), manufacturer: \(manufacturer))" )
}
do {
let audioUnit = try await AVAudioUnit.instantiate(
with: component.audioComponentDescription, options: AudioComponentInstantiationOptions.loadOutOfProcess)
self.avAudioUnit = audioUnit
self.connect(avAudioUnit: audioUnit)
return await audioUnit.loadAudioUnitViewController()
} catch {
return nil
}
}
private func startPlayingInternal() {
guard let avAudioUnit = self.avAudioUnit else { return }
setSessionActive(true)
if avAudioUnit.wantsAudioInput { scheduleEffectLoop() }
let hardwareFormat = engine.outputNode.outputFormat(forBus: 0)
engine.connect(engine.mainMixerNode, to: engine.outputNode, format: hardwareFormat)
do { try engine.start() } catch {
isPlaying = false
fatalError("Could not start engine. error: \(error).")
}
if avAudioUnit.wantsAudioInput { player.play() }
isPlaying = true
}
private func resetAudioLoop() {
guard let avAudioUnit = self.avAudioUnit else { return }
if avAudioUnit.wantsAudioInput {
guard let format = file?.processingFormat else { fatalError("No AVAudioFile defined.") }
engine.connect(player, to: engine.mainMixerNode, format: format)
}
}
public func connect(avAudioUnit: AVAudioUnit?, completion: @escaping (() -> Void) = {}) {
guard let avAudioUnit = self.avAudioUnit else { return }
engine.disconnectNodeInput(engine.mainMixerNode)
resetAudioLoop()
engine.detach(avAudioUnit)
func rewiringComplete() {
scheduleMIDIEventListBlock = auAudioUnit.scheduleMIDIEventListBlock
if isPlaying { player.play() }
completion()
}
let hardwareFormat = engine.outputNode.outputFormat(forBus: 0)
engine.connect(engine.mainMixerNode, to: engine.outputNode, format: hardwareFormat)
if isPlaying { player.pause() }
let auAudioUnit = avAudioUnit.auAudioUnit
if !auAudioUnit.midiOutputNames.isEmpty { auAudioUnit.midiOutputEventBlock = midiOutBlock }
engine.attach(avAudioUnit)
if avAudioUnit.wantsAudioInput {
engine.disconnectNodeInput(engine.mainMixerNode)
if let format = file?.processingFormat {
engine.connect(player, to: avAudioUnit, format: format)
engine.connect(avAudioUnit, to: engine.mainMixerNode, format: format)
}
} else {
let stereoFormat = AVAudioFormat(standardFormatWithSampleRate: hardwareFormat.sampleRate, channels: 2)
engine.connect(avAudioUnit, to: engine.mainMixerNode, format: stereoFormat)
}
rewiringComplete()
}
}
and my MIDI Manager
@MainActor
class MIDIManager: Identifiable, ObservableObject {
func setupPort(midiProtocol: MIDIProtocolID,
receiveBlock: @escaping @Sendable MIDIReceiveBlock) -> Bool {
guard setupClient() else { return false }
if MIDIInputPortCreateWithProtocol(client, portName, midiProtocol, &port, receiveBlock) != noErr {
return false
}
for source in self.sources {
if MIDIPortConnectSource(port, source, nil) != noErr {
print("Failed to connect to source \(source)")
return false
}
}
setupVirtualMIDIOutput()
return true
}
private func setupVirtualMIDIOutput() {
let virtualStatus = MIDISourceCreate(client, virtualSourceName, &virtualSource)
if virtualStatus != noErr {
print("❌ Failed to create virtual MIDI source: \(virtualStatus)")
} else {
print("✅ Created virtual MIDI source: \(virtualSourceName)")
}
}
func sendMIDIData(_ data: [UInt8]) {
print("hey")
var packetList = MIDIPacketList()
withUnsafeMutablePointer(to: &packetList) { ptr in
let pkt = MIDIPacketListInit(ptr)
_ = MIDIPacketListAdd(ptr, 1024, pkt, 0, data.count, data)
if virtualSource != 0 {
let status = MIDIReceived(virtualSource, ptr)
if status != noErr {
print("❌ Failed to send MIDI data: \(status)")
} else {
print("✅ Sent MIDI data: \(data)")
}
}
}
}
}
Hi,
I've had a new deck installed in my car for about 1.5 weeks.
I'm having compatibility issues with my 15PM.
It happens both wired and wirelessly, I get the error "Accessory not supported by this device". It used to happen all the time, now it's 50/50. Sometimes it works.
I've removed and added Bluetooth multiple times on phone and deck, I bought a belkin usb-c to usb-a cable today and it seems to fix it but the problem comes back.
I've changed the setting "FaceID and passcode-allow access when locked-accessories."
The car stereo guy reckons it's definitely an issue with the phone not the deck, I'm inclined to believe him since the error states "by this device".
Any advice appreciated.
Topic:
Media Technologies
SubTopic:
Audio
Since iOS 18, the system setting “Allow Audio Playback” (enabled by default) allows third-party app audio to continue playing while the user is recording video with the Camera app. This has created a problem for the app I’m developing.
➡️ The problem:
My app plays continuous audio in both foreground and background states. If the user starts recording video using the iOS Camera app, the app’s audio — still playing in the background — gets captured in the video — obviously an unintended behavior.
Yes, the user could stop the app manually before starting the video recording, but that can’t be guaranteed. As a developer, I need a way to stop the app’s audio before the video recording begins.
So far, I haven’t found a reliable way to detect when video recording starts if ‘Allow Audio Playback’ is ON.
➡️ What I’ve tried:
— AVAudioSession.interruptionNotification → doesn’t fire
— devicesChangedEventStream → not triggered
I don’t want to request mic permission (app doesn’t use mic). also, disabling the app from playing audio in the background isn’t an option as it is a crucial part of the user experience
➡️ What I need:
A reliable, supported way to detect when the Camera app begins video recording, without requiring mic access — so I can stop audio and avoid unintentional overlap with the user’s recordings.
Any official guidance, workarounds, or AVFoundation techniques would be greatly appreciated.
Thanks.
Session player regions populate blank, with no sound media when tracks or regions are created.
I noticed that while playing back the same tracks via MusicKit on different OSes I get different results regarding the audio files being streamed.
Playing back a lossless file with 24Bit 48kHz and watching the Console for RemotePlayerService I get:
on iPadOS: Lossless; groupID: audio-alac-stereo-48000-24; bitDepth: 24-bit; sampleRate: 48khz; codec: alac; channels: 2; layout: Stereo;
on macOS: Creating AudioQueue with format:'paac', framesPerPacket:1024, sampleRate:44100
While the iPad looks perfect, the Mac does not. Is there a way to fix this issue on macOS.
BTW: I switched the Audio-Midi Settings before, after and while the macOS App was lunched. I also switched to different output devices. I wasn't able to change the bad audio-output on the mac. I tested this under Sequoia 15.5 and Tahoe beta 1, Xcode 16.4 and 26 beta 1.
The AudioVariants of the Album/Tracks are .dolbyAtmos, .lossless, .lossyStereo
Apple Music displays Lossless 24 Bit/48 kHz ALAC when clicking on the playercontroll icon on macOS
I hope there are only some missing or misconfigured properties to get macOS up to par.
Thanks :-)
I developed an educational app that implements audio-video communication through RTC, while using WebView to display course materials during classes. However, some users are experiencing an issue where the audio playback from WebView is very quiet. I've checked that the AVAudioSessionCategory is set by RTC to AVAudioSessionCategoryPlayAndRecord, and the AVAudioSessionCategoryOption also includes AVAudioSessionCategoryOptionMixWithOthers. What could be causing the WebView audio to be suppressed, and how can this be resolved?
My audio app shows a control bar at the bottom of the window. The controls show nicely, but there is a black "slab" appearing behind the inline controls, the same size as the playerView. Setting the player view background color does nothing:
playerView.wantsLayer = true playerView.layer?.backgroundColor = NSColor.clear.cgColor
How can I clear the background?
If I use .floating controlsStyle, I don't get the background "slab".
Topic:
Media Technologies
SubTopic:
Audio