I've filed this as FB21446798 but figured I'd post here too.
In the first build of macOS 26.3, playback via ApplicationMusicPlayer is completely broken. When starting playback of anything at all, the console shows the following error:
applicationController: xpc service connection interrupted
Failed to obtain remoteObject: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service created from an endpoint was invalidated from this process." UserInfo={NSDebugDescription=The connection to service created from an endpoint was invalidated from this process.}
Failed to prepareToPlay with error: Error Domain=MPMusicPlayerControllerErrorDomain Code=10 "(null)" UserInfo={NSUnderlyingError=0xc92910ff0 {Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service created from an endpoint was invalidated from this process." UserInfo={NSDebugDescription=The connection to service created from an endpoint was invalidated from this process.}}}
In addition, several crash logs for RemotePlayerService are generated, showing my app as the parent process.
This issue is 100% repeatable. No matter how I load the queue, whether it’s catalog or library content, any variation I can think of all fails like this.
I really hope this can be fixed before 26.3 comes out, otherwise my app will be totally unusable. 😅
Audio
RSS for tagDive into the technical aspects of audio on your device, including codecs, format support, and customization options.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Created
Recently, after the update of 26.3 Mac OS (Tahoe), the ordering of my music app has been horrible at best - music disappearing, tracks not aligning with albums (even if the albums are different years).
It's created quite a problem, because the disappearing tracks issue seems to be replicating to iOS devices as well (although track numbering and album association seem to be stable). Has anyone else heard of this issue?
Topic:
Media Technologies
SubTopic:
Audio
Currently, I have successfully used ChannelMap to map hardware input channels and obtained audio data from the hardware device's MIC and OTG inputs. Additionally, I have used ChannelMap to map output channels to freely feed data for playback to each output channel. However, I now have a problem.
I have a hardware device that only has output channels (no input channels), and the system has set this hardware device as the default playback device. In this case, how can I obtain the audio data being played to the output channels for modification?
I'm seeing crashes in _MPRemoteCommandEventDispatch on iOS 26.x devices in 3 apps. According to Bugsnag logs they are:
NSInternalInconsistencyException: event dispatch <_MPRemoteCommandEventDispatch: <MPRemoteCommandEvent: 0x11c049500 commandID=THV0 command=<MPRemoteCommand: 0x109ad1ea0 type=Play (0) enabled=YES handlers=[0x109b6a310]> sourceID=(null) ([HostedRoutingSessionDataSource] handleControlSendingCommand<2W5E>)> state:201> deallocated without calling continuation
I attached a log from Xcode organizer matching Bugsnag crash.
mpr_remote_command_event.crash
When I set the brakpoint on the -[_MPRemoteCommandEventDispatch dealloc] I can see it it's hit every time I tap play or pause on locked screen play button.
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x00000002370420cc __pthread_kill + 8 (:-1)
1 libsystem_pthread.dylib 0x00000001e975c810 pthread_kill + 268 (pthread.c:1721)
2 libsystem_c.dylib 0x0000000198f8ff64 abort + 124 (abort.c:122)
3 libc++abi.dylib 0x000000018a7cf808 __abort_message + 132 (abort_message.cpp:66)
4 libc++abi.dylib 0x000000018a7be484 demangling_terminate_handler() + 304 (cxa_default_handlers.cpp:76)
5 libobjc.A.dylib 0x000000018a6cff78 _objc_terminate() + 156 (objc-exception.mm:496)
6 xxxxxxxxxxxxxx 0x00000001003a7db8 CPPExceptionTerminate() + 416 (BSG_KSCrashSentry_CPPException.mm:156)
7 libc++abi.dylib 0x000000018a7cebdc std::__terminate(void (*)()) + 16 (cxa_handlers.cpp:59)
8 libc++abi.dylib 0x000000018a7ceb80 std::terminate() + 108 (cxa_handlers.cpp:88)
9 CoreFoundation 0x000000018d7341c4 __CFRunLoopPerCalloutARPEnd + 256 (CFRunLoop.c:769)
10 CoreFoundation 0x000000018d70bb5c __CFRunLoopRun + 1976 (CFRunLoop.c:3179)
11 CoreFoundation 0x000000018d70aa6c _CFRunLoopRunSpecificWithOptions + 532 (CFRunLoop.c:3462)
12 GraphicsServices 0x000000022e31c498 GSEventRunModal + 120 (GSEvent.c:2049)
13 UIKitCore 0x00000001930ceba4 -[UIApplication _run] + 792 (UIApplication.m:3902)
14 UIKitCore 0x0000000193077a78 UIApplicationMain + 336 (UIApplication.m:5577)
15 xxxxxxxxxxxxxx 0x00000001000c0134 main + 308 (main.swift:15)
16 dyld 0x000000018a722e28 start + 7116 (dyldMain.cpp:1477)
Is the crash happening when the app is being terminated?
Thank you!
I'm using the new SpeechAnalyzer framework to detect certain commands and want to improve accuracy by giving context. Seems like AnalysisContext is the solution for this, but couldn't find any usage example. So I want to make sure that I'm doing it right or not.
let context = AnalysisContext()
context.contextualStrings = [
AnalysisContext.ContextualStringsTag("commands"): [
"set speed level",
"set jump level",
"increase speed",
"decrease speed",
...
],
AnalysisContext.ContextualStringsTag("vocabulary"): [
"speed", "jump", ...
]
]
try await analyzer.setContext(context)
With this implementation, it still gives outputs like "Set some speed level", "It's speed level", etc.
Also, is it possible to make it expect number after those commands, in order to eliminate results like "set some speed level to" (instead of two).
The sysEx struct in the MIDIUniversalMessage struct has a channel member but the System Exclusive (7-Bit) Message doesn't have a channel field.
The System Exclusive (7-Bit) Message has a # of bytes field but the sysEx struct doesn't have a nrOfBytes, byteCount or bytesUsed member.
It looks like the channel member of the sysEx struct contains the number of used bytes.
Is this a mistake in the header or did I misunderstand something?
using iOS 26.2; Airpods 4
Long press stem to launch Siri
Speak "Record Voice Memo" -> Recording starts
Recording in progress...
Long press stem to launch Siri -> Nothing happens.
To stop recording need use phone.
is this intended behaviour?
i would like to be able to stop recording with Siri
I am able to launch Siri from phone while recording, but point is to keep phone in pocket and start/stop recordings only via Airpods.
My app utilizes background audio to play music files. I have the audio background mode enabled and I initialize the AVAudioSession in playback mode with the mixWithOthers option. And it usually works great while the app is backgrounded. I listen for audio interruptions as well as route changes and I am able to handle them appropriately and I can usually resume my background audio no problem.
I discovered an issue while connected to CarPlay though. Roughly 50% of the time when I disconnect from a phone call while connected to CarPlay I get the following error after calling the play() method of my AVAudioPlayer instance:
"ATAudioSessionClientImpl.mm:281 activation failed. status = 561015905"
If I instead try to start a new audio session I get a similar error:
Error Domain=NSOSStatusErrorDomain Code=561015905 "Session activation failed" UserInfo={NSLocalizedDescription=Session activation failed}
Like I said, this isn't reproducible 100% of the time and is so far only seen while connected to CarPlay. I don't think Im forgetting so additional capability or plist setting, but if anyone has any clues it would be greatly appreciated. Otherwise this is likely just a bug that I need to report to Apple.
One very important note, and reason I believe it's just a bug, is that while I was testing I found that other music apps like Spotify will also fail to resume their audio at the same time my app fails.
Another important detail is that when it works successfully I receive the audio session interruption ended notification, and when it doesn't work I only receive a route configuration change or route override notification. From there I am able to still successfully granted background time to execute code, but my call to resume audio fails with the above mentioned error codes.
I'm encountering errors while using AVAudioEngine with voice processing enabled (setVoiceProcessingEnabled(true)) in scenarios where the input and output audio devices are not the same. This issue arises specifically with mismatched devices, preventing the application from functioning as expected.
Works: Paired devices (e.g., MacBook Pro mic → MacBook Pro speakers) Fails: Mismatched devices (e.g., AirPods mic → MacBook Pro speakers)
When using paired input and output devices:
The setup works as expected. Example: MacBook Pro microphone → MacBook Pro speakers. When using mismatched devices:
AVAudioEngine setup fails during aggregate device construction. Example: AirPods microphone → MacBook Pro speakers. Error logs indicate a channel count mismatch.
Here are the partial logs. Due to the content limit, I cannot post the entire logs.
AUVPAggregate.cpp:1000 client-side input and output formats do not match (err=-10875)
AUVPAggregate.cpp:1036 err=-10875
AVAEInternal.h:109 [AVAudioEngineGraph.mm:1344:Initialize: (err = PerformCommand(*outputNode, kAUInitialize, NULL, 0)): error -10875
AggregateDevice.mm:329 Failed expectation of constructed aggregate (312): mInput.streamChannelCounts == inputStreamChannelCounts
AggregateDevice.mm:331 Failed expectation of constructed aggregate (312): mInput.totalChannelCount == std::accumulate(inputStreamChannelCounts.begin(), inputStreamChannelCounts.end(), 0U)
AggregateDevice.mm:182 error fetching default pair
AggregateDevice.mm:329 Failed expectation of constructed aggregate (336): mInput.streamChannelCounts == inputStreamChannelCounts
AggregateDevice.mm:331 Failed expectation of constructed aggregate (336): mInput.totalChannelCount == std::accumulate(inputStreamChannelCounts.begin(), inputStreamChannelCounts.end(), 0U)
AUHAL.cpp:1782 ca_verify_noerr: [AudioDeviceSetProperty(mDeviceID, NULL, 0, isInput, kAudioDevicePropertyIOProcStreamUsage, theSize, theStreamUsage), 560227702]
AudioHardware-mac-imp.cpp:3484 AudioDeviceSetProperty: no device with given ID
AUHAL.cpp:1782 ca_verify_noerr: [AudioDeviceSetProperty(mDeviceID, NULL, 0, isInput, kAudioDevicePropertyIOProcStreamUsage, theSize, theStreamUsage), 560227702]
AggregateDevice.mm:182 error fetching default pair
AggregateDevice.mm:329 Failed expectation of constructed aggregate (348): mInput.streamChannelCounts == inputStreamChannelCounts
AggregateDevice.mm:331 Failed expectation of constructed aggregate (348): mInput.totalChannelCount == std::accumulate(inputStreamChannelCounts.begin(), inputStreamChannelCounts.end(), 0U)
Is it possible to use voice processing with different input/output devices?
If yes, are there any specific configurations required to handle mismatched devices? How can we resolve channel count mismatch errors during aggregate device construction?
Are there settings or API adjustments to enforce compatibility between input/output devices? Are there any workarounds or alternative approaches to achieve voice processing functionality with mismatched devices?
For instance, can we force an intermediate channel configuration or downmix input/output formats?
I have a flutter iOS app that has some simple sound FX for button clicks, swipes, etc.
In simulator and on real device the sound works fine, but when i upload the app to testflight (and App store) the sound FX don't play. When I upload the app to my phone via xcode I am using the release profile so I don't see what the difference could be.
I have also gone through the archive that i uploaded and verified that the sound files are indeed there.
I have other flutter apps that use sound but non since the iOS 26 update. I've tried 3 different flutter sound libraries and all face the same issue.
Wondering if anyone else is seeing this issue or if I'm missing a simple permission or something that has changed recently?
Thanks in advanced
Topic:
Media Technologies
SubTopic:
Audio
Hello,
I've discovered a buffer initialization bug in AVAudioUnitSampler that happens when loading presets with multiple zones referencing different regions in the same audio file (monolith/concatenated samples approach).
Almost all zones output silence (i.e. zeros) at the beginning of playback instead of starting with actual audio data.
The Problem
Setup:
Single audio file (monolith) containing multiple concatenated samples
Multiple zones in an .aupreset, each with different sample start and sample end values pointing to different regions of the same file
All zones load successfully without errors
Expected Behavior:
All zones should play their respective audio regions immediately from the first sample.
Actual Behavior:
Last zone in the zone list: Works perfectly - plays audio immediately
All other zones: Output [0, 0, 0, 0, ..., _audio_data] instead of [real_audio_data]
The number of zeros varies from event to event for each zone. It can be a couple of samples (<30) up to several buffers.
After the initial zeros, the correct audio plays normally, so there is no shift in audio playback, just missing samples at the beginning.
Minimal Reproduction
1. Create Test Monolith Audio File
Create a single Wav file with 3 concatenated 1-second samples (44.1kHz):
Sample 1: frames 0-44099 (constant amplitude 0.3)
Sample 2: frames 44100-88199 (constant amplitude 0.6)
Sample 3: frames 88200-132299 (constant amplitude 0.9)
2. Create Test Preset
Create an .aupreset with 3 zones all referencing the same file:
Pseudo code
<Zone array>
<zone 1> start : 0, end: 44099, note: 60, waveform: ref_to_monolith.wav;
<zone 2> start sample: 44100, note: 62, end sample: 88199, waveform: ref_to_monolith.wav;
<zone 3> start sample: 88200, note: 64, end sample: 132299, waveform: ref_to_monolith.wav;
</Zone array>
3. Load and Test
// Load preset into AVAudioUnitSampler
let sampler = AVAudioUnitSampler()
try sampler.loadAudioFiles(from: presetURL)
// Play each zone (MIDI notes C4=60, D4=62, E4=64)
sampler.startNote(60, withVelocity: 64, onChannel: 0) // Zone 1
sampler.startNote(62, withVelocity: 64, onChannel: 0) // Zone 2
sampler.startNote(64, withVelocity: 64, onChannel: 0) // Zone 3
4. Observed Result
Zone 1 (C4): [0, 0, 0, ..., 0.3, 0.3, 0.3] ❌ Zeros at beginning
Zone 2 (D4): [0, 0, 0, ..., 0.6, 0.6, 0.6] ❌ Zeros at beginning
Zone 3 (E4): [0.9, 0.9, 0.9, ...] ✅ Works correctly (last zone)
What I've Extensively Tested
What DOES Work
Separate files per zone:
Each zone references its own individual audio file
All zones play correctly without zeros
Problem: Not viable for iOS apps with 500+ sample libraries due to file handle limitations
What DOESN'T Work (All Tested)
1. Different Audio Formats:
CAF (Float32 PCM, Int16 PCM, both interleaved and non-interleaved)
M4A (AAC compressed)
WAV (uncompressed)
SF2 (SoundFont2)
Bug persists across all formats
2. CAF Region Chunks:
Created CAF files with embedded region chunks defining zone boundaries
Set zones with no sampleStart/sampleEnd in preset (nil values)
AVAudioUnitSampler completely ignores CAF region metadata
Bug persists
3. Unique Waveform IDs:
Gave each zone a unique waveform ID (268435456, 268435457, 268435458)
Each ID has its own file reference entry (all pointing to same physical file)
Hypothesized this might trigger separate buffer initialization
Bug persists - no improvement
4. Different Sample Rates:
Tested: 44.1kHz, 48kHz, 96kHz
Bug occurs at all sample rates
5. Mono vs Stereo:
Bug occurs with both mono and stereo files
Environment
macOS: Sonoma 14.x (tested across multiple minor versions)
iOS: Tested on iOS 17.x with same results
Xcode: 16.x
Frameworks: AVFoundation, AudioToolbox
Reproducibility: 100% reproducible with setup described above
Impact & Use Case
This bug severely impacts professional music applications that need:
Small file sizes: Monolith files allow sharing compressed audio data (AAC/M4A)
iOS file handle limits: Opening 400+ individual sample files is not viable on iOS
Performance: Single file loading is much faster than hundreds of individual files
Standard industry practice: Monolith/concatenated samples are used by EXS24, Kontakt, and most professional samplers
Current Impact:
Cannot use monolith files with AVAudioUnitSampler on iOS
Forced to choose between: unusable audio (zeros at start) OR hitting iOS file limits
No viable workaround exists
Root Cause Hypothesis
The bug appears to be in AVAudioUnitSampler's internal buffer initialization when:
Multiple zones share the same source audio file
Each zone specifies different sampleStart/sampleEnd offsets
Key observation: The last zone in the zone array always works correctly.
This is NOT related to:
File permissions or security-scoped resources (separate files work fine)
Audio codec issues (happens with uncompressed PCM too)
Preset parsing (preset loads correctly, all zones are valid)
Questions
Is this a known issue? I couldn't find any documentation, bug reports, or discussions about this.
Is there ANY workaround that allows monolith files to work with AVAudioUnitSampler?
Alternative APIs? Is there a different API or approach for iOS that properly supports monolith sample files?
I wrote a Swift macOS app to control a PCI audio device. The code switches between the default output and input channels. As soon as I launch the Audio-Midi Setup utility, channel switching stops working. The driver properties allow switching, but the system doesn't respond. I have to delete the contents of /Library/Preferences/Audio and reset Core Audio. What am I missing?
func setDefaultChannelsOutput() {
guard let deviceID = getDeviceIDByName(deviceName: "PCI-424") else { return }
let selectedIndex = DefaultChannelsOutput.indexOfSelectedItem
if selectedIndex < 0 || selectedIndex >= 24 { return }
let channel1 = UInt32(selectedIndex * 2 + 1)
let channel2 = UInt32(selectedIndex * 2 + 2)
var channels: [UInt32] = [channel1, channel2]
var propertyAddress = AudioObjectPropertyAddress(
mSelector: kAudioDevicePropertyPreferredChannelsForStereo,
mScope: kAudioDevicePropertyScopeOutput,
mElement: kAudioObjectPropertyElementWildcard
)
let dataSize = UInt32(MemoryLayout<UInt32>.size * channels.count)
let status = AudioObjectSetPropertyData(deviceID, &propertyAddress, 0, nil, dataSize, &channels)
if status != noErr {
print("Error setting default output channels: \(status)")
}
}
Topic:
Media Technologies
SubTopic:
Audio
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
【溦N51888M】腾龙公司会员申请流程步骤【罔纸 211239.com 】输入官惘到浏览器打开联系24小时在线业务人员办理上下,打开公司官网.
二、点击主页右上角注册按钮.
三、填写账号信息.
四、输入手机号,验证码,密码.
五、勾选用户协议,完成注册协议,完成注册.
注意:若出现账号已存在」提示,需重新设置唯一账号名称
Topic:
Media Technologies
SubTopic:
Audio
hi all,
as soon an audio is played in a whatever app, coreaudiod inserts a sleep prevent assertion for both, the system AND the display.
can i somehow stop the insertion of the display sleep assertion?
pid 223(coreaudiod): [0x00004e9e00058dc2] 00:03:18 PreventUserIdleDisplaySleep named: "com.apple.audio.AppleGFXHDAEngineOutputDP:10001:0:{B31A-08C6-00000000}.context.preventuseridledisplaysleep"
Created for PID: 4145.
where PID 4145 is spotify.
but it doesn't matter which app is playing the audio.
any help would be appreciated
thanks
Topic:
Media Technologies
SubTopic:
Audio
I have a Catalyst app ('container') which hosts an embedded AUv3 Audio Unit extension ('plugin'). This used to work for years and has worked with this project until a few days ago.
it still works on iOS as expected
on MacOS the extension is never registered/installed and won't load
extension won't show up with AUVal
seems to have stopped working with the 26.1 XCode update
I'm fairly certain the problem is not code related (i.e. likely build settings, project settings, entitlements, signing, etc.)
I have compared all settings with another still-working project and can't find any meaningful difference
(I can't request code-level support because even the minimal thing vastly exceeds the 250 lines of code limit.)
How can I debug the issue? I literally don't know where to start to fix this problem, short of rebuilding the entire thing and hope that it magically starts working again.
I have the new iOS 26 SpeechTranscriber working in my application. The issue I am facing is how to determine if the device I am running on supports SpeechTranscriber. I was able to create code that tests if the device supports transcription but it takes a bit of time to run and thus the results are not available when the app launches. What I am looking for is a list of what iOS 26 devices it doesn't run on. I think its safe to assume any new devices will support it so if we can just have a list of what devices that can run iOS 26 and not able to do transcription it would be much faster for the app. I have determined it doesn't work on a SE 2nd Gen, it works on iPhone 12, SE 3rd Gen, iPhone 14 Pro, 15 Pro. As the SpeechTranscriber doesn't work in the simulator I can't determine that way. I have checked the docs and it doesn't list the devices it doesn't work on.
Hi, everyone, I downloaded the source code EditingSpatialAudioWithAnAudioMix.zip from https://developer.apple.com/documentation/Cinematic/editing-spatial-audio-with-an-audio-mix, when I carried out one of the actions named "process" in command line the program crashed!!
Form the source code, I found that the value of componentType is set to kAudioUnitType_FormatConverter:
// The actual `AudioUnit`.
public var auAudioMix = AVAudioUnitEffect()
init() {
// Generate a component description for the audio unit.
let componentDescription = AudioComponentDescription(
componentType: kAudioUnitType_FormatConverter,
componentSubType: kAudioUnitSubType_AUAudioMix,
componentManufacturer: kAudioUnitManufacturer_Apple,
componentFlags: 0,
componentFlagsMask: 0)
auAudioMix=AVAudioUnitEffect(audioComponentDescription: componentDescription)
}
But in the document from https://developer.apple.com/documentation/avfaudio/avaudiouniteffect/init(audiocomponentdescription:), it seems that componentType can not be set to kAudioUnitType_FormatConverter and :
Has everyone encountered this problem?
Hi there,
I recently launched a dj app to the mac app store, and was wondering how I could access songs for mixing purposes via Apple Music just like how serato, rekordbox, djay, and other DJ apps do?
Thanks,
Gunek
I’m running the iOS 26.2 Public Beta update and my album artwork is missing from the music app (I’m not using Apple Music). I use google to get my album artwork. Do I need to wait for a new update?
Topic:
Media Technologies
SubTopic:
Audio