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
Audio
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Hi,
when a CoreMIDI driver controls physical HW it is probably quite commune to have to control the amount of MIDI data received from the system.
What comes to mind is to just delay returning control of the MIDIDriverInterface::Send() callback to the calling process. While the application trying to send MIDI really stalls until the callback returns it seems only to be a side effect of a generally stalled CoreMIDI server. Between the callbacks the application can send as much MIDI data as it wants to CoreMIDI, it's buffering seems to be endless... However the HW might not be able to play out all the data.
It seems there is no way to indicate an overflow/full buffer situation back the application/CoreMIDI. How is this supposed to work?
Thanks, any hints or pointers are highly appreciated!
Hagen.
Hi,
I’m an iOS developer building an app with an use case that needs advanced playback on Apple Music subscription streams, specifically:
• Real-time tempo change (BPM) during playback — i.e., time-stretch with key-lock, not just crossfade.
• Beat-matched transitions between tracks.
From what I can tell, this capability seems to exist only for approved partners and isn’t available through public MusicKit.
Question: What’s the official request path to be evaluated for that restricted partner entitlement (application form, questionnaire, NDA, or internal team/BD contact)? If the entitlement identifier is internal, how can I get my account routed to the right Apple Music team?
For reference, publicly announced partners include Algoriddim djay, Serato DJ Pro, rekordbox (AlphaTheta), and Engine DJ—all of which appear to implement mixing features that imply advanced playback (tempo/beat-matching) on Apple Music content. I’d prefer not to share product details publicly for the moment and can provide specifics privately if needed.
Thanks in advance!
Topic:
Media Technologies
SubTopic:
Audio
Tags:
Apple Music API
FairPlay Streaming
MusicKit
AVFoundation
I'm writing a simple app for iOS and I'd like to be able to do some text to speech in it. I have a basic audio manager class with a "speak" function:
import Foundation
import AVFoundation
class AudioManager {
static let shared = AudioManager()
var audioPlayer: AVAudioPlayer?
var isPlaying: Bool {
return audioPlayer?.isPlaying ?? false
}
var playbackPosition: TimeInterval = 0
func playSound(named name: String) {
guard let url = Bundle.main.url(forResource: name, withExtension: "mp3") else {
print("Sound file not found")
return
}
do {
if audioPlayer == nil || !isPlaying {
audioPlayer = try AVAudioPlayer(contentsOf: url)
audioPlayer?.currentTime = playbackPosition
audioPlayer?.prepareToPlay()
audioPlayer?.play()
} else {
print("Sound is already playing")
}
} catch {
print("Error playing sound: \(error.localizedDescription)")
}
}
func stopSound() {
if let player = audioPlayer {
playbackPosition = player.currentTime
player.stop()
}
}
func speak(text: String) {
let synthesizer = AVSpeechSynthesizer()
let utterance = AVSpeechUtterance(string: text)
utterance.voice = AVSpeechSynthesisVoice(language: "en-GB")
synthesizer.speak(utterance)
}
}
And my app shows text in a ScrollView:
ScrollView {
Text(self.description)
.padding()
.foregroundColor(.black)
.font(.headline)
.background(Color.gray.opacity(0))
}.onAppear {
AudioManager.shared.speak(text: self.description)
}
However, the text doesn't get read out (in the simulator). I see some output in the console:
Error fetching voices: Swift.DecodingError.dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "Invalid container metadata for _UnkeyedDecodingContainer, found keyedGraphEncodingNodeID", underlyingError: nil)). Using fallback voices.
I'm probably doing something wrong here, but not sure what.
Topic:
Media Technologies
SubTopic:
Audio
After upgrading to watchOS 26, users report that when playing music on Apple Watch, if a fitness reminder is received, the music automatically pauses and users need to manually tap the play button to resume music playback. This phenomenon occurs with multiple music and podcast apps.
This issue did not exist before the upgrade. We would like to know if this is an Apple bug or if there are any special development configurations needed?"
New to iOS development and I've been trying to make heads or tails of the documentation. I know there is a difference between the data fields returned from songs from the user library and from the category, but whenever I search on the apple site I can't find a list of each. For example, Im trying to get the releaseDate of a song in my library, but it seems I'll have to cross-query either the catalog entry for the using song.catalogID or the song.irsc but when I try to use them I can't find a cross reference between the two. I'm totally turned around.
Also trying to determine if a song in my library has been favorited or not? isFavorited (or something similar) doesn't seem to be a thing. Using this code and trying to find a way to display a solid star if the song has been favorited or an empty one if it's not. Seems like a basic request but I can't find anything on how to do it. I've searched docs, googled, tried.
Does apple want us to query the user's Favorited Songs playlist or something? How do I know which playlist that is?
I know isFavorited isn't a thing, just using it here so you can see what my intension is:
HStack(spacing: 10) {
Image(systemName: song.isFavorited ? "star.fill" : "star")
.foregroundColor(song.isFavorited ? .yellow : .gray)
Image(systemName: "magnifyingglass")
}
The AVB AVnu MILAN Convention has a groweing Population. Many big companies (Cisco, Meyer Sound, d&b Audio, l‘acoustics, Presonus, digico etc.) implements the AVB AVnu Milan Standards. Is there a plan on the Apple side to also implement AVnu Milan on top of the AVB Protocol?
The advantage for Apple Sound would be a great Integration in the professionell Audio market and a more stable intergration on top of the AVB protocol. The atdecc work, but Not that stable.
Topic:
Media Technologies
SubTopic:
Audio
We require assistance in resolving a critical audio design conflict within our Push-to-Talk (PTT) application. Our current volume amplification strategy—which relies on applying a GAIN factor to PCM samples in conjunction with setting the AVAudioSession category to Playback—is working successfully when PTT is used independently. However, upon integrating and reporting the same PTT call through the CallKit framework, this amplification effect is lost. The CallKit integration appears to be forcing a different, non-amplifying audio session category or configuration, negatively impacting the user's perceived call volume. We need guidance on how to maintain the AVAudioSessionCategoryPlayback setting, or an equivalent high-volume configuration, while operating under the control of CallKit.
Hi,
I'm still stuck getting a basic record-with-playthrouh pipeline to work.
Has anyone a sample of setting up a AVAudioEngine pipeline for recording with playthrough?
Plkaythrough works with AVPlayerNode as input but not with any microphone input. The docs mention the "enabled state" of the outputNode of the engine without explaining the concept, i.e. how to enable an output.
When the engine renders to and from an audio device, the AVAudioSession category and the availability of hardware determines whether an app performs output. Check the output node’s output format (specifically, the hardware format) for a nonzero sample rate and channel count to see if output is in an enabled state.
Well, in my setup the output is NOT enabled, and any attempt to switch (e.g. audioEngine.outputNode.auAudioUnit.setDeviceID(deviceID) )/ attach a dedicated device / ... results in exceptions / errors
Using the PushToTalk library, call requestBeginTransmitting (channelUUID: UUID) on a Bluetooth device and then use the PTChannelManagerial Delegate proxy method channelManager:(PTChannelManager *)channelManager didActivateAudioSession:(AVAudioSession *)audioSession Start recording sound inside. Completed recording
Hello!
We stumbled upon a problem with our karaoke app where user on iPhone 16e/iOS 18.5 has problem with mic capture, other users cannot hear him. The mic capture is working fine on 17.5, 16.8. Maybe there is something else we need when configuring AVAudioSession for iOS 18.5?
Currently it's set up like this:
override func viewDidLoad() {
super.viewDidLoad()
UIApplication.shared.isIdleTimerDisabled = true
mRoomId = appDelegate.getRoomId()
let audioSession = AVAudioSession.sharedInstance()
try! audioSession.setCategory(.playAndRecord, mode: .voiceChat, options: [.defaultToSpeaker])
try! audioSession.setPreferredSampleRate(48000)
try! audioSession.setActive(true, options: [])
}
Topic:
Media Technologies
SubTopic:
Audio
I have both apple devices, AirPods Pro 3 is up to date and Ultra 3 is on watch os 26.1 latest public beta.
Each morning when I would go on my mindfulness app and start a meditation or listen to Apple Music on my watch and AirPods Pro 3, it will play for a few seconds then disconnects. My bluetooth settings on my watch says my AirPods is connected to my watch. I also have removed the tick about connecting automatically to iPhone on the AirPods setting in my iPhone.
To fix this I invariably turn off my Apple Watch Ultra 3 and turn it on again. Then the connection becomes stable. I am not sure why I have to do this each morning. It is frustrating. I am not sure why this fix does not last long? Is there something wrong with my AirPods?
Has anyone encountered this before?
Hi everyone, I’m working on an iOS MusicKit app that overlays a metronome on top of Apple Music playback. To line the clicks up perfectly I’d like access to low-level audio analysis data—ideally a waveform / spectrogram or beat grid—while the track is playing. I’ve noticed that several approved DJ apps (e.g. djay, Serato, rekordbox) can already: • Display detailed scrolling waveforms of Apple Music songs • Scratch, loop or time-stretch those tracks in real time That implies they receive decoded PCM frames or at least high-resolution analysis data from Apple Music under a special entitlement. My questions: 1. Does MusicKit (or any public framework) expose real-time audio buffers, FFT bins, or beat markers for streaming Apple Music content? 2. If not, is there an Apple program or entitlement that developers can apply for—similar to the “DJ with Apple Music” initiative—to gain that deeper access? 3. Where can I find official documentation or a point of contact for this kind of request? I’ve searched the docs and forums but only see standard MusicKit playback APIs, which don’t appear to expose raw audio for DRM-protected songs. Any guidance, links or insider tips on the proper application process would be hugely appreciated! Thanks in advance.
Topic:
Media Technologies
SubTopic:
Audio
{
"aps": { "content-available": 1 },
"audio_file_name": "ding.caf",
"audio_url": "https://example.com/audio.mp3"
}
When the app is in the background or killed, it receives a remote APNs push. The data format is roughly as shown above. How can I play the MP3 audio file at the specified "audio_url"? The user does not need to interact with the device when receiving the APNs. How can I play the audio file immediately after receiving it?
Hi,
I try to record audio on the iPhone with the AVAudioRecorder and Xcode 26.0.1.
Maybe the problem is that I can not record audio with the simulator. But there's a menu for audio.
In the plist I added 'Privacy - Microphone Usage Description' and I ask for permission before recording.
if await AVAudioApplication.requestRecordPermission() {
print("permission granted")
recordPermission = true
} else {
print("permission denied")
}
Permission is granted.
let settings: [String : Any] = [
AVFormatIDKey: kAudioFormatMPEG4AAC,
AVSampleRateKey: 12000,
AVNumberOfChannelsKey: 1,
AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
]
recorder = try AVAudioRecorder(url: filename, settings: settings)
let prepared = recorder.prepareToRecord()
print("prepared started: \(prepared)")
let started = recorder.record()
print("recording started: \(started)")
started is always false and I tried many settings.
Error messages
AddInstanceForFactory: No factory registered for id <CFUUID 0x600000211480> F8BB1C28-BAE8-11D6-9C31-00039315CD46
AudioConverter.cpp:1052 Failed to create a new in process converter -> from 0 ch, 12000 Hz, .... (0x00000000) 0 bits/channel, 0 bytes/packet, 0 frames/packet, 0 bytes/frame to 1 ch, 12000 Hz, aac (0x00000000) 0 bits/channel, 0 bytes/packet, 1024 frames/packet, 0 bytes/frame, with status -50
AudioQueueObject.cpp:1892 BuildConverter: AudioConverterNew returned -50
from: 0 ch, 12000 Hz, .... (0x00000000) 0 bits/channel, 0 bytes/packet, 0 frames/packet, 0 bytes/frame
to: 1 ch, 12000 Hz, aac (0x00000000) 0 bits/channel, 0 bytes/packet, 1024 frames/packet, 0 bytes/frame
prepared started: true
AudioQueueObject.cpp:7581 ConvertInput: aq@0x10381be00: AudioConverterFillComplexBuffer returned -50, packetCount 5
recording started: false
All examples I find are the same, but apparently there must be something different.
After update,WeChat voice chatting no sounds, please help
Hi everyone 👋
I’m building an iOS app in Swift where I want to do the following:
Record the user’s voice
Transcribe the spoken sentence (speech-to-text)
Auto-detect the spoken language
Translate it to another language selected by the user (e.g., English → Spanish or Hindi → English)
Speak back (text-to-speech) the translated text on the same device
Is this possible to record via phone mic and play the transcribe voice into headphone's audio?
Hi,
I'm trying to setup a AVAudioEngine for USB Audio recording and monitoring playthrough.
As soon as I try to setup playthough I get an error in the console: AVAEInternal.h:83 required condition is false: [AVAudioEngineGraph.mm:1361:Initialize: (IsFormatSampleRateAndChannelCountValid(outputHWFormat))]
Any ideas how to fix it?
// Input-Device setzen
try? setupInputDevice(deviceID: inputDevice)
let input = audioEngine.inputNode
// Stereo-Format erzwingen
let inputHWFormat = input.inputFormat(forBus: 0)
let stereoFormat = AVAudioFormat(commonFormat: inputHWFormat.commonFormat, sampleRate: inputHWFormat.sampleRate, channels: 2, interleaved: inputHWFormat.isInterleaved)
guard let format = stereoFormat else {
throw AudioError.deviceSetupFailed(-1)
}
print("Input format: \(inputHWFormat)")
print("Forced stereo format: \(format)")
audioEngine.attach(monitorMixer)
audioEngine.connect(input, to: monitorMixer, format: format)
// MonitorMixer -> MainMixer (Output)
// Problem here, format: format also breaks.
audioEngine.connect(monitorMixer, to: audioEngine.mainMixerNode, format: nil)
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.
I have an iPadOS M-processor application with two different running configurations.
In config1, the shared AVAudioSession is configured for .videoChat mode using the built-in microphone. The input/output nodes of the AVAudioEngine are configured with voice processing enabled. The built-in mic is formatted for 1 channel at 48KHz.
In config2, the shared AVAudioSession is configured for .measurement mode using an external USB microphone. The input/output nodes of the AVAudioEngine are configured with voice processing disabled. The external mic is formatted for 2 channels at 44.1KHz
I've written a configuration manager designed to safely switch between these two configurations. It works by stopping AVAudioEngine and detaching all but the input and output nodes, updating the shared audio session for the desired mic and sample-rates, and setting the appropriate state for voice processing to either true or false as required by the configuration. Finally the new audio graph is constructed by attaching appropriate nodes, connecting them, and re-starting AVAudioEngine
I'm experiencing what I believe is a race-condition between switching voice processing on or off and then trying to re-build and start the new audio graph. Even though notifications, which are dumped to the console indicate that my requested input and sample-rate settings are in place, I crash when trying to start the audio engine because the sample-rate is wrong. Investigating further it looks like the switch from remote I/O to voice-processing I/O or vice-versa has not yet actually completed. I introduced a 100ms second delay and that seems to help but is obviously not a reliable way to build software that must work consistently.
How can I make sure that what are apparently asynchronous configuration changes to the shared audio session and the input/output nodes have completed before I go on?
I tried using route change notifications from the shared AVAudioSession but these lie. They say my preferred mic input and sample-rate setting is in place but when I dump the AVAudioEngine graph to the debugger console, I still see the wrong sample rate assigned to the input/output nodes. Also these are the wrong AU nodes. That is, VPIO is still in place when RIO should be, or vice-versa.
How can I make the switch reliable without arbitrary time delays?
Is my configuration manager approach appropriate (question for Apple engineers)?