I found that the aggregated device correctly obtains input channels in the standard microphone mode. However, in voice isolation mode, it only retrieves channels from the first sub-device in the aggregated device's list. If I want to properly obtain channel information in voice isolation mode, how should I do it?
Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.
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Hello! I have been following the UsingAVFoundationToPlayAndPersistHTTPLiveStreams sample code in order to test persisting streams to disk. In addition to support for m3u8, I have noticed in testing that this also seems to work for MP3 Audio, simply by changing the plist entries to point to remote URLs with audio/mpeg content. Is this expected, or are there caveats that I should be aware of?
Thanks you!
Hi,
I'm developing a SwiftUI app using RealityKit and ARKit for an AR measuring feature. I’ve noticed that after navigating away from my AR view and performing extensive cleanup (including removing all anchors/entities, pausing the ARSession, and nil-ing out all references), memory usage remains elevated and sometimes grows with repeated AR sessions.
Each time I enter and exit the AR view, memory increases
The memory does not return to the baseline after cleanup, even though all custom objects are deallocated.
Are there best practices beyond what I’ve described to ensure all ARKit/RealityKit resources are released after an AR session?
I have an app under development - demo here - https://youtu.be/VbAfUk_eYl0?si=s6EDBx-4G6P_QbZO - which is sort of an audio player for airdropped files - something useful to musicians who dump work in progress to their phone, make notes, revise and update.
I've been testing my handling of audio session interruption notifications, but seems to be a lot of inconsistency in how, when and why iOS delivers them, and I'm wondering if there is some rhyme or reason to it that I'm just not detecting.
For example, I am playing a song in my app. Switch to Apple Music and start playing a song there. My app gets an interruption began notification - this is consistent.
Switch back to my app, and about half the time, I will get an interruption ended notification (coupled often with a blast of the tail of whatever audio buffer was partially played when the interruption started, even though the engine was stopped - and followed by call to my AVAudioPlayerNodeCompletionCallback - is there some way to avoid this?). Half the time I don't get an interruption ended notification; my app can (as expected) end the interruption by activating the AVAudioSession and playing something.
I have not been able to determine any pattern to this behavior, other than that if my app started playing using AVAudioPlayerNode.scheduleSegment rather than scheduleFile I think the notification will be consistently delivered on app activation rather than when I activate the session programmatically.
I would like my app to behave deterministically, and would appreciate any help in deciphering what causes the inconsistent behavior in notifications from iOS.
In Final Cut Pro, keyframes for transform parameters (such as Position, Scale, and Rotation) are automatically set to “Smooth” interpolation. This often results in undesired easing between keyframes, especially when linear motion is required.
Currently, we have to manually adjust each keyframe to "Linear" using the Video Animation Editor, which can be time-consuming when working with many keyframes.
Would it be possible to add an option to set the default keyframe interpolation to "Linear"—either globally in Preferences or per parameter in the Inspector?
This would greatly streamline the animation workflow for many editors.
Thank you for considering this request!
I'm developing a TTS Audio Unit Extension that needs to write trace/log files to a shared App Group container. While the main app can successfully create and write files to the container, the extension gets sandbox denied errors despite having proper App Group entitlements configured.
Setup:
Main App (Flutter) and TTS Audio Unit Extension share the same App Group
App Group is properly configured in developer portal and entitlements
Main app successfully creates and uses files in the container
Container structure shows existing directories (config/, dictionary/) with populated files
Both targets have App Group capability enabled and entitlements set
Current behavior:
Extension can access/read the App Group container
Extension can see existing directories and files
All write attempts are blocked with "sandbox deny(1) file-write-create" errors
Code example:
const char* createSharedGroupPathWithComponent(const char* groupId, const char* component) {
NSString* groupIdStr = [NSString stringWithUTF8String:groupId];
NSString* componentStr = [NSString stringWithUTF8String:component];
NSURL* url = [[NSFileManager defaultManager]
containerURLForSecurityApplicationGroupIdentifier:groupIdStr];
NSURL* fullPath = [url URLByAppendingPathComponent:componentStr];
NSError *error = nil;
if (![[NSFileManager defaultManager] createDirectoryAtPath:fullPath.path
withIntermediateDirectories:YES
attributes:nil
error:&error]) {
NSLog(@"Unable to create directory %@", error.localizedDescription);
}
return [[fullPath path] UTF8String];
}
Error output:
Sandbox: simaromur-extension(996) deny(1) file-write-create /private/var/mobile/Containers/Shared/AppGroup/36CAFE9C-BD82-43DD-A962-2B4424E60043/trace
Key questions:
Are there additional entitlements required for TTS Audio Unit Extensions to write to App Group containers?
Is this a known limitation of TTS Audio Unit Extensions?
What is the recommended way to handle logging/tracing in TTS Audio Unit Extensions?
If writing to App Group containers is not supported, what alternatives are available?
Current entitlements:
<dict>
<key>com.apple.security.application-groups</key>
<array>
<string>group.com.<company>.<appname></string>
</array>
</dict>
Short summary
When setting exposureMode to .locked or .custom the brightness of a video stream still changes depending on the composition and contrast of the visible scene. These changes seem to come from contrast enhancements or dynamic range optimizations and totally break any analysis of the image that requires to assess absolute luminance. While exposure lock seems to indeed lock the physical exposure parameters of the camera (shutter speed and ISO), I cannot find any way to control these "soft" modifiers.
Details
Background
I am the developer of the app "phyphox", an educational app that makes the phone's sensors accessible to students as measurement tools in science experiments. Currently I am working on implementing photometric measurements through the camera and one very important aspect of it is luminance measurements.
This is particularly relevant since the light sensor of the phone has no publicly accessible API and the camera could to some extend make experiments available to Apple users that are otherwise only possible on Android devices.
Implementation
The app uses AVFoundation and explicitly picks individual cameras since camera groups do not support custom exposure settings. This means that it handles camera switching during zoom by itself and even implements its own auto exposure routines to optimize for the use in experiments. Therefore it always stays in custom exposure mode. The app uses YUV420 color space and the individual frames are analyzed in Metal using compute shaders.
However, the effects discussed here still occur if I remove all code to control the camera and replace it with a simple sequence of setting the exposure mode to custom, setting custom exposure values, setting a fixed white balance and then setting the exposure mode to locked as suggested on stackoverflow. This neither helps on an iPhone 14 Pro nor on an iPhone 8 despite a report on the developer forums that it would resolve the issue for older devices.
The app is open source, so the code can be seen in our current development branch (without the changes for the tests here, though) on github.
The videos below use the implementation with the suggestion from stackoverflow, but they can be reproduced in the same way with "professional" camera apps that promise manual control over the camera (like the Blackmagic cam to quote a reputable company) as well as the stock camera app after pressing and holding on the preview to enable AE/AF lock.
Demonstration
These examples were captured on an iPhone 14 Pro. The central part of the image (highlighted by the app using metal shaders after capture) should not change with fixed exposure settings, but significant changes are noticable if there are changes at the edge of the frame when I move a black piece of cardboard in from above:
https://share.icloud.com/photos/0b1f_3IB6yAQG-qSH27pm6oDQ
The graph above the camera preview is the average luminance (gamma corrected and weighted based on sRGB) across the highlighted central area and as mentioned before it should not change because of something happening at the side of the frame (worst case it should get a bit darker because of the cardboard's shadow).
In my opinion, the iPhone changes its mind on the ideal contrast as soon as it has a different exposure histogram because of the dark image part from the cardboard, but that's just me guessing.
For completeness here is the same effect in the stock camera app with AE/AF lock enabled:
https://share.icloud.com/photos/0cd7QM8ucBZKwPwE9mybnEowg
Here you can also see that the iPhone "ramps" the changes. The brightness of the gray area does not change immediately but transitions smoothly, so this is clearly deliberate postprocessing.
So...
Any suggestion on how to prevent this behavior would be highly appreciated.
According to the doc, I did a simple demo to verify.
My env:
ProductName: macOS
ProductVersion: 15.5
BuildVersion: 24F74
2.4 GHz 四核Intel Core i5
Info.plist:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>IOKitPersonalities</key>
<dict>
<key>UVCamera</key>
<dict>
<key>CFBundleIdentifierKernel</key>
<string>com.apple.kpi.iokit</string>
<key>IOClass</key>
<string>IOUserService</string>
<key>IOMatchCategory</key>
<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
<key>IOProviderClass</key>
<string>IOUserResources</string>
<key>IOResourceMatch</key>
<string>IOKit</string>
<key>IOUserClass</key>
<string>UVCamera</string>
<key>IOUserServerName</key>
<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
<key>IOProbeScore</key>
<integer>100000</integer>
<key>idVendor</key>
<integer>1452</integer>
<key>idProduct</key>
<integer>34068</integer>
</dict>
</dict>
<key>OSBundleUsageDescription</key>
<string></string>
</dict>
</plist>
UVCamera.cpp
//
// UVCamera.cpp
// UVCamera
//
// Created by DTEN on 2025/6/12.
//
#include <os/log.h>
#include <DriverKit/IOUserServer.h>
#include <DriverKit/IOLib.h>
#include "UVCamera.h"
kern_return_t
IMPL(UVCamera, Start)
{
kern_return_t ret;
ret = Start(provider, SUPERDISPATCH);
os_log(OS_LOG_DEFAULT, "Hello World");
return ret;
}
UVCamera.iig
//
// UVCamera.iig
// UVCamera
//
// Created by DTEN on 2025/6/12.
//
#ifndef UVCamera_h
#define UVCamera_h
#include <Availability.h>
#include <DriverKit/IOService.iig>
class UVCamera: public IOService
{
public:
virtual kern_return_t
Start(IOService * provider) override;
};
#endif /* UVCamera_h */
Then I build by xcode and mv it to /Library/DriverExtensions:
sudo mv com.lqs.MyVirtualCam.UVCamera.dext /Library/DriverExtensions
sudo kmutil install -R / -r /Library/DriverExtensions
kmutil rebuild done
However,the dext can't be loaded:
kmutil showloaded --list-only | grep UVCamera
No variant specified, falling back to release
What's the problem? anyone can help me?
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
It sounds simple but searching for the name "Favorite Songs" is a non-starter because it's called different names in different countries, even if I specify "&l=en_us" on the query.
So is there another property, relationship or combination thereof which I can use to tell me when I've found the right playlist?
Properties I've looked at so far:
canEdit: will always be false so narrows things down a little
inFavorites: not helpful as it depends on whether the user has favourite the favourites playlist, so not relevant
hasCatalog: seems always true so again may narrow things down a bit
isPublic: doesn't help
Adding the catalog relationship doesn't seem to show anything immediately useful either.
Can anyone help?
Ideally I'd like to see this as a "kind" or "type" as it has different properties to other playlists, but frankly I'll take anything at this point.
I am developing an app that uses MusicKit to play music and then I need to have spoken words played to the user, while ducking the audio coming from MusicKit (application music player)
the built in Siri voices are not off sufficient quality so I am using an external service to create an mp3 file and then play this back using AVAudioSession
Sample code below
the problem I am having is that .duckOthers is not ducking the Application Music Player output
Is this a bug or am I doing this wrong?
// Configure audio session for system-wide ducking
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .spokenAudio, options: [.duckOthers, .mixWithOthers])
try AVAudioSession.sharedInstance().setActive(true)
// Set the ducking level to maximum
try AVAudioSession.sharedInstance().setPreferredIOBufferDuration(0.005)
// Create and configure audio player
self.audioPlayer = try AVAudioPlayer(data: audioData)
self.audioPlayer?.delegate = self
self.audioPlayer?.volume = 1.0 // Ensure full volume for speech
self.audioPlayer?.prepareToPlay()
// Set the audio player's settings for maximum clarity
self.audioPlayer?.enableRate = false
self.audioPlayer?.pan = 0.0 // Center the audio
self.audioPlayer?.play()
I have an app that displays artwork via MPMediaItem.artwork, requesting an image with a specific size. How do I get a media item's MPMediaItemAnimatedArtwork, and how to get the preview image and video to display to the user?
who can help me to make app for iOS with XCode
Topic:
Media Technologies
SubTopic:
Streaming
We have a React website build to scan qr codes. The website is properly working for Android devices but for Iphone we see a camera glitch causing delay in scan which is unexpected.
Website URL : https://react-qr-code-scanner-app.vercel.app/
Topic:
Media Technologies
SubTopic:
Photos & Camera
On some devices, loadFileRepresentation(forTypeIdentifier: completionHandler) take a loong time(about two minute) to callback result for some large video(about 200 MB, take by device camera).
environment:
Model: iPhone 12
Model Number: MGGM3CH/A
iOS Version: 18.3.2
PHPickerResult.NSItemProvider.loadFileRepresentation()
// import PhotosUI
func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
picker.dismiss(animated: true, completion: nil)
guard let provider = results.last?.itemProvider else { return }
guard provider.hasItemConformingToTypeIdentifier(UTType.movie.identifier) else {
return
}
Task {
provider.loadFileRepresentation(forTypeIdentifier: UTType.movie.identifier) { url, error in
guard let url = url else {
return
}
// Do some stuff...
}
}
}
ps: I also try some other function, eg: provide.loadItem(forTypeIdentifier:), but not work too.
hi,
i need to read wether the transport is playing or stopped but my current method that works for vst does not work for au.
is there a lpx resource available for developers anywhere?
if (auto* playHead = processor->getPlayHead())
{
juce::AudioPlayHead::CurrentPositionInfo posInfo;
if (playHead->getCurrentPosition(posInfo))
{
bool isCurrentlyPlaying = posInfo.isPlaying;
if (isCurrentlyPlaying != wasTransportPlaying)
{
if (isCurrentlyPlaying)
{
wasTransportPlaying = isCurrentlyPlaying;
startAllTimers();
}
else
{
wasTransportPlaying = isCurrentlyPlaying;
stopAllTimers();
}
}
}
}
thanks :)
The device is connected to Bluetooth A and Bluetooth B, currently the audio is played through Bluetooth A, click the interface button, how to realize the code to switch to Bluetooth B?
ImageIO encoding to HEICS fails in macOS 15.5.
log
writeImageAtIndex:1246: *** CMPhotoCompressionSessionAddImageToSequence: err = kCMPhotoError_UnsupportedOperation [-16994] (codec: 'hvc1')
seems to be related with
https://github.com/SDWebImage/SDWebImage/issues/3732
affected version
iOS 18.4 (sim and device), macOS 15.5
unaffected version
iOS 18.3 (sim and device), macOS 15.3
I have integrated the ShazamKit SDK into my iOS app and would like to implement the same functionality in my Android app.
My question is: Can I use the Android version of the ShazamKit SDK for commercial purposes?
After extensive research, I could not find any official information regarding the license of the Android version of the ShazamKit SDK.
Could you please provide a formal license statement?
Hi guys,
I am having issue in live-streaming audio from Bluetooth headset and playing it live on the iPhone speaker.
I am able to redirect audio back to the headset but this is not what I want.
The issue happens when I am trying to override output - the iPhone switches to speaker but also switches a microphone.
This is example of the code:
import AVFoundation
class AudioRecorder {
let player: AVAudioPlayerNode
let engine:AVAudioEngine
let audioSession:AVAudioSession
let audioSessionOutput:AVAudioSession
init() {
self.player = AVAudioPlayerNode()
self.engine = AVAudioEngine()
self.audioSession = AVAudioSession.sharedInstance()
self.audioSessionOutput = AVAudioSession()
do {
try self.audioSession.setCategory(AVAudioSession.Category.playAndRecord, options: [.defaultToSpeaker])
try self.audioSessionOutput.setCategory(AVAudioSession.Category.playAndRecord, options: [.allowBluetooth]) // enables Bluetooth HFP profile
try self.audioSession.setMode(AVAudioSession.Mode.default)
try self.audioSession.setActive(true)
// try self.audioSession.overrideOutputAudioPort(.speaker) // doens't work
} catch {
print(error)
}
let input = self.engine.inputNode
self.engine.attach(self.player)
let bus = 0
let inputFormat = input.inputFormat(forBus: bus)
self.engine.connect(self.player, to: engine.mainMixerNode, format: inputFormat)
input.installTap(onBus: bus, bufferSize: 512, format: inputFormat) { (buffer, time) -> Void in
self.player.scheduleBuffer(buffer)
print(buffer)
}
}
public func start() {
try! self.engine.start()
self.player.play()
}
public func stop() {
self.player.stop()
self.engine.stop()
}
}
I am not sure if this is a bug or not.
Can somebody point me into the right direction?
I there a way to design a custom audio routing?
I would also appreciate some good documentation besides AVFoundation docs.