Hi, I'm trying to plan out development of an app and am wondering if it is possible to have user generated content automatically populate into a custom shazamkit catalogue and be able to query this catalogue non-locally?
Storing all the submissions locally would obviously not scale.
Audio
RSS for tagDive into the technical aspects of audio on your device, including codecs, format support, and customization options.
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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.
Hello. My app uses AVAudioRecorder to generate recording files, which are consistently only 4kb in size. Most users generate audio files normally, with only a few users experiencing this phenomenon occasionally. After uninstalling and installing the app, it will work normally, but it will reappear after a period of time. I have compared that the problematic audio files generated each time are fixed and cannot be played. Added the audioRecorderDidFinishRecording proxy method, which shows that the recording was completed normally. The user also reported that the recording is normal, but there is a problem with the generated file. How should I handle this issue? Look forward to your reply.
- (void)startRecordWithOrderID:(NSString *)orderID {
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryRecord error:nil];
[audioSession setActive:YES error:nil];
NSMutableDictionary *settings = [[NSMutableDictionary alloc] init];
[settings setObject:[NSNumber numberWithFloat: 8000.0] forKey:AVSampleRateKey];
[settings setObject:[NSNumber numberWithInt: kAudioFormatLinearPCM] forKey:AVFormatIDKey];
[settings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[settings setObject:[NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey];
[settings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
[settings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];
NSString *path = [WDUtility createDirInDocument:@"audios" withOrderID:orderID withPathExtension:@"wav"];
NSURL *tmpFile = [NSURL fileURLWithPath:path];
recorder = [[AVAudioRecorder alloc] initWithURL:tmpFile settings:settings error:nil];
[recorder setDelegate:self];
[recorder prepareToRecord];
[recorder record];
}
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
I am developing an iOS app that needs to play spoken audio on demand from a server, while ducking the audio of background music from another app (e.g., SoundtrackYourBrand or Apple Music). This must work even when the app is in the background, and the server dictates when and what audio is played. Ideally, the message should be played within a minute of the server requesting it.
Current Attempt & Observations
I initially tried using Firebase Cloud Messaging (FCM) silent notifications to send a URL to an audio file, which the app would then play using AVPlayer.
This works consistently when the app is active, but in the background, it only works about 60% of the time.
In cases where it fails, iOS ducks the background music (e.g., from SoundtrackYourBrand) but never plays the spoken audio.
Interestingly, when I play the audio without enabling audio ducking, it seems to work 100% of the time from my limited testing, even in the background.
The app has background modes enabled for Audio, Background Fetch, and Remote Notifications.
Best Approach to Achieve This?
I’d like guidance on the best Apple-compliant approach to reliably play audio on command from the server, even when the app is in the background. Some possible paths:
Ensuring the app remains active in the background – Are there recommended ways to prevent the app from getting suspended, such as background tasks, a special background mode, or a persistent connection to the server?
Alternative triggering mechanisms – Would something like VoIP, Push-to-Talk, or another background service be better suited for this use case?
Built-in iOS speech synthesis (AVSpeechSynthesizer) – If playing external audio is unreliable, would generating speech dynamically from text be a more robust approach?
Streaming audio instead of sending a URL – Could continuous streaming from the server keep the app active and allow playback at the right moment?
I want to ensure the solution is reliable and works 100% of the time when needed. Any recommendations on the best approach for this would be greatly appreciated.
Thank you for your time and guidance.
I prefer to use the album fetched from the library instead of the catalog since this is faster. If doing so, how can I check if all tracks of an album are added to the library. In this case I'd like to fetch the catalog version or throw an error (for example when offline).
Using .with(.tracks) on the library album fetches the tracks added to the library.
The trackCount property is referring to the tracks that can be fetched from the library.
The isComplete property is always nil when fetching from the library.
One possible way is checking the trackNumber and discCount properties. However this only detects that not all tracks of an album are added to the library if there is a song not added ahead of one that is. I'd like to be able to handle this edge case as well.
Is there currently a way to do this? I'd prefer to not rely on the apple music catalog for this since this is supposed to work offline as well. Fetching and storing all trackIDs when connected and later comparing against these would work, but this would potentially mean storing tens of thousands of track ids.
Thank you
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
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 folks - I'm having trouble finding specific documentation about Audio Unit MIDI plugins - as in MIDI -only. Any suggestions welcome as searches aren't returning much. (too niche? user error?)
Topic:
Media Technologies
SubTopic:
Audio
I am developing a VOD playback app, but when I stream video to an external monitor connected via HDMI with Lightning on iOS 18 or later, the screen goes dark and I cannot confirm playback.
The app I am developing does not detect the HDMI and display the Player separately, but simply mirrors the video.
We have confirmed that the same phenomenon occurs with other services, but we were able to confirm playback with some services such as Apple TV.
Please let us know if there are any other necessary settings such as video certificates required for video playback.
We would also like to know if the problem occurs with iOS 18 or later.
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.
We are currently working on a CarPlay navigation app and so far everything is working well except for speaking turn notifications.
Our TTS implementation works fine on the phone and works fine on CarPlay if the voice is spoken over the speaker in the car. If users connect a BT headset to the car and listen through that headset, then the voice commands are chopped up / stutter.
Why would users use BT headset? Well, we are working on a motorcycle app, and there are no speakers usually on a motorcycle.
It sounds like the BT channel is opened and closed repeatedly for every character / word spoken. This happens on different CarPlay devices and different Bluetooth headsets, we have reports from multiple users that they find this behavior annoying and that other apps work fine.
Is this a known issue? Are there possible workaround?
Two issues:
No matter what I set in
try audioSession.setPreferredSampleRate(x)
the sample rate on both iOS and macOS is always 48000 when the output goes through the speaker, and 24000 when my Airpods connect to an iPhone/iPad.
Now, I'm checking the current output loudness to animate a 3D character, using
mixerNode.installTap(onBus: 0, bufferSize: y, format: nil) { [weak self] buffer, time in
Task { @MainActor in
// calculate rms and animate character accordingly
but any buffer size under 4800 is just ignored and the buffers I get are 4800 sized.
This is ok, when the sampleRate is currently 48000, as 10 samples per second lead to decent visual results.
But when AirPods connect, the samplerate is 24000, which means only 5 samples per second, so the character animation looks lame.
My AVAudioEngine setup is the following:
audioEngine.connect(playerNode, to: pitchShiftEffect, format: format)
audioEngine.connect(pitchShiftEffect, to: mixerNode, format: format)
audioEngine.connect(mixerNode, to: audioEngine.outputNode, format: nil)
Now, I'd be fine if the outputNode runs at whatever if it needs, as long as my tap would get at least 10 samples per second.
PS: Specifying my favorite format in the
let format = AVAudioFormat(standardFormatWithSampleRate: 48_000, channels: 2)!
mixerNode.installTap(onBus: 0, bufferSize: y, format: format)
doesn't change anything either
AVAudioFormat has no Swift concurrency annotations but the documentation states "Instances of this class are immutable."
This made me always assume it was safe to pass AVAudioFormat instances around. Is this the case? If so can it be marked as Sendable? Am I missing something?
I've got a problem with my app where I'm testing it on my own phone.
I'm using audio kit to generate tones as part of the app. Everything seems to work fine. Sounds start, Stop, etc. They play when the app is closed and when the phone is locked, so background is working.
However, I'm seeing an issue where, even when STOP is pressed and the application exited, if I get a notification such as a text message, the base tone for the app starts to play.
If I then open the app, check the Start/Stop button - it says start so that. hasnt' been activated. If I click Start, then a 2nd tone starts. This one stops with the Stop button. However the original tone that was set off by an incoming message carries on playing.
Until I go to the Open Apps View on the phone and slide the application upwards.
For the life of me, I can't figure out whats happening here.
iPadOS 18.3 beta 3 (22D5055b) fixed the issue for me and my 7th generation iPad.
Topic:
Media Technologies
SubTopic:
Audio
I have a simple AVAudioEngine graph as follows:
AVAudioPlayerNode -> AVAudioUnitEQ -> AVAudioUnitTimePitch -> AVAudioUnitReverb -> Main mixer node of AVAudioEngine.
I noticed that whenever I have AVAudioUnitTimePitch or AVAudioUnitVarispeed in the graph, I noticed a very distinct crackling/popping sound in my Airpods Pro 2 when starting up the engine and playing the AVAudioPlayerNode and unable to find the reason why this is happening. When I remove the node, the crackling completely goes away. How do I fix this problem since i need the user to be able to control the pitch and rate of the audio during playback.
import AVKit
@Observable @MainActor
class AudioEngineManager {
nonisolated private let engine = AVAudioEngine()
private let playerNode = AVAudioPlayerNode()
private let reverb = AVAudioUnitReverb()
private let pitch = AVAudioUnitTimePitch()
private let eq = AVAudioUnitEQ(numberOfBands: 10)
private var audioFile: AVAudioFile?
private var fadePlayPauseTask: Task<Void, Error>?
private var playPauseCurrentFadeTime: Double = 0
init() {
setupAudioEngine()
}
private func setupAudioEngine() {
guard let url = Bundle.main.url(forResource: "Song name goes here", withExtension: "mp3") else {
print("Audio file not found")
return
}
do {
audioFile = try AVAudioFile(forReading: url)
} catch {
print("Failed to load audio file: \(error)")
return
}
reverb.loadFactoryPreset(.mediumHall)
reverb.wetDryMix = 50
pitch.pitch = 0 // Increase pitch by 500 cents (5 semitones)
engine.attach(playerNode)
engine.attach(pitch)
engine.attach(reverb)
engine.attach(eq)
// Connect: player -> pitch -> reverb -> output
engine.connect(playerNode, to: eq, format: audioFile?.processingFormat)
engine.connect(eq, to: pitch, format: audioFile?.processingFormat)
engine.connect(pitch, to: reverb, format: audioFile?.processingFormat)
engine.connect(reverb, to: engine.mainMixerNode, format: audioFile?.processingFormat)
}
func prepare() {
guard let audioFile else { return }
playerNode.scheduleFile(audioFile, at: nil)
}
func play() {
DispatchQueue.global().async { [weak self] in
guard let self else { return }
engine.prepare()
try? engine.start()
DispatchQueue.main.async { [weak self] in
guard let self else { return }
playerNode.play()
fadePlayPauseTask?.cancel()
playPauseCurrentFadeTime = 0
fadePlayPauseTask = Task { [weak self] in
guard let self else { return }
while true {
let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: true)
// Ramp up volume until 1 is reached
if volume >= 1 { break }
engine.mainMixerNode.outputVolume = volume
try await Task.sleep(for: .milliseconds(10))
playPauseCurrentFadeTime += 0.01
}
engine.mainMixerNode.outputVolume = 1
}
}
}
}
func pause() {
fadePlayPauseTask?.cancel()
playPauseCurrentFadeTime = 0
fadePlayPauseTask = Task { [weak self] in
guard let self else { return }
while true {
let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: false)
// Ramp down volume until 0 is reached
if volume <= 0 { break }
engine.mainMixerNode.outputVolume = volume
try await Task.sleep(for: .milliseconds(10))
playPauseCurrentFadeTime += 0.01
}
engine.mainMixerNode.outputVolume = 0
playerNode.pause()
// Shut down engine once ramp down completes
DispatchQueue.global().async { [weak self] in
guard let self else { return }
engine.pause()
}
}
}
private func updateVolume(for x: Double, rising: Bool) -> Float {
if rising {
// Fade in
return Float(pow(x, 2) * (3.0 - 2.0 * (x)))
} else {
// Fade out
return Float(1 - (pow(x, 2) * (3.0 - 2.0 * (x))))
}
}
func setPitch(_ value: Float) {
pitch.pitch = value
}
func setReverbMix(_ value: Float) {
reverb.wetDryMix = value
}
}
struct ContentView: View {
@State private var audioManager = AudioEngineManager()
@State private var pitch: Float = 0
@State private var reverb: Float = 0
var body: some View {
VStack(spacing: 20) {
Text("🎵 Audio Player with Reverb & Pitch")
.font(.title2)
HStack {
Button("Prepare") {
audioManager.prepare()
}
Button("Play") {
audioManager.play()
}
.padding()
.background(Color.green)
.foregroundColor(.white)
.cornerRadius(10)
Button("Pause") {
audioManager.pause()
}
.padding()
.background(Color.red)
.foregroundColor(.white)
.cornerRadius(10)
}
VStack {
Text("Pitch: \(Int(pitch)) cents")
Slider(value: $pitch, in: -2400...2400, step: 100) { _ in
audioManager.setPitch(pitch)
}
}
VStack {
Text("Reverb Mix: \(Int(reverb))%")
Slider(value: $reverb, in: 0...100, step: 1) { _ in
audioManager.setReverbMix(reverb)
}
}
}
.padding()
}
}
Hi,
I'm working on a project that uses the AVSpeechSynthesizer and AVSpeechUtterance.
I discovered by chance that the AVSpeechSynthesizer automatically completes some words instead of just outputting what it's supposed to.
These are abbreviations for days of the week or months, but not all of them. I don't want either of them automatically completed, but only the specified text. The completion transcends languages.
I have written a short example program for demonstration purposes.
import SwiftUI
import AVFoundation
import Foundation
let synthesizer: AVSpeechSynthesizer = AVSpeechSynthesizer()
struct ContentView: View {
var body: some View {
VStack {
Button {
utter("mon")
} label: {
Text("mon")
}
.buttonStyle(.borderedProminent)
Button {
utter("tue")
} label: {
Text("tue")
}
.buttonStyle(.borderedProminent)
Button {
utter("thu")
} label: {
Text("thu")
}
.buttonStyle(.borderedProminent)
Button {
utter("feb")
} label: {
Text("feb")
}
.buttonStyle(.borderedProminent)
Button {
utter("feb", lang: "de-DE")
} label: {
Text("feb DE")
}
.buttonStyle(.borderedProminent)
Button {
utter("wed")
} label: {
Text("wed")
}
.buttonStyle(.borderedProminent)
}
.padding()
}
private func utter(_ text: String, lang: String = "en-US") {
let utterance = AVSpeechUtterance(string: text)
let voice = AVSpeechSynthesisVoice(language: lang)
utterance.voice = voice
synthesizer.speak(utterance)
}
}
#Preview {
ContentView()
}
Thank you
Christian
I’ve been researching how to achieve a recording playback effect in iOS similar to the hands-free calling effect in the system’s phone app. How can this be implemented? I tried using the voice chat recording method, but found that the volume of the speaker output is too low. How should this issue be addressed? I couldn’t find a suitable API. Could you provide me with some documentation or sample code? Thank you.
Hi!
I get personal recommendations MusicItemCollection using this code:
func getRecommendations() async throws -> MusicItemCollection<MusicPersonalRecommendation> {
let request = MusicPersonalRecommendationsRequest()
let response = try await request.response()
let recommendations = response.recommendations
return recommendations
}
However, all recommendations contain no more than 12 MusicItem's, while the Music.app application provides much more for some recommendations, for example, for the You recently listened recommendation, the Music.app application displays 40 items. Each recommendation has an items property that contains a collection of musical items MusicItemCollection<MusicPersonalRecommendation.Item>, the hasNextBatch property for these collections is always false. I expected that for some collections loading of new items would be available. Please tell me if I'm doing something wrong or is this a MusicKit bug?
Thank you!