I'm working on adding CarPlay support to an audio app and am running into an issue. Occasionally, when a user opens the app from CarPlay while the main app scene is either not connected or is currently in the background, I will receive an error when attempting to activate the audio session. The code below mimics my setup:
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .spokenAudio)
try AVAudioSession.sharedInstance().setActive(true)
} catch {
print(error) // NSOSStatusErrorDomain - 560557684: Session activation failed
}
That error code maps to AVAudioSession.ErrorCode.cannotInterruptOthers.
Once in this state, all subsequent attempts to play different pieces of content will fail. However, things will start working normally if the user opens the app on their phone and tries again from CarPlay (while the app is in the foreground on their phone).
I'm not sure why it would behave this way and want to note that I do have the audio background mode capability enabled.
Has anyone else encountered this? Are there any workarounds or changes I could make to prevent this from happening?
Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.
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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?
Hello, Apple video engineers.
According to the official documentation, HLS is built on HTTP and traditionally ran on top of TCP. However, with the introduction of HTTP/3, which uses QUIC (runs on top of UDP), I would like to clarify the following:
Has the official HLS specification changed in a way that allows it to be considered UDP-based when using HTTP/3? And is it fair to say that HLS supports UDP since the transport can go over HTTP/3 and QUIC?
Would it be more accurate to say that HLS remains HTTP-dependent, and the transport protocol (TCP or QUIC) only determines how HTTP requests are delivered?
My thoughts: Since HTTP/3 uses QUIC running over UDP, we still can't say that HLS supports UDP in a classical way, as it is introduced in RTP, RTSP, SRT.
I'm writing some camera functionality that uses AVCaptureVideoDataOutput.
I've set it up so that it calls my AVCaptureVideoDataOutputSampleBufferDelegate on a background thread, by making my own dispatch_queue and configuring the AVCaptureVideoDataOutput.
My question is then, if I configure my AVCaptureSession differently, or even stop it altogether, is this guaranteed to flush all pending jobs on my background thread?
I have a more practical example below, showing how I am accessing something from the foreground thread from the background thread, but I wonder when/how it's safe to clean up that resource.
I have setup similar to the following:
// Foreground thread logic
dispatch_queue_t queue = dispatch_queue_create("avf_camera_queue", nullptr);
AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];
setupInputDevice(captureSession); // Connects the AVCaptureDevice...
// Store some arbitrary data to be attached to the frame, stored on the foreground thread
FrameMetaData frameMetaData = ...;
MySampleBufferDelegate *sampleBufferDelegate = [MySampleBufferDelegate alloc];
// Capture frameMetaData by reference in lambda
[sampleBufferDelegate setFrameMetaDataGetter: [&frameMetaData]() { return &frameMetaData; }];
AVCaptureVideoDataOutput *captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
[captureVideoDataOutput setSampleBufferDelegate:sampleBufferDelegate
queue:queue];
[captureSession addOutput:captureVideoDataOutput];
[captureSession startRunning];
[captureSession stopRunning];
// Is it now safe to destroy frameMetaData, or do we need manual barrier?
And then in MySampleBufferDelegate:
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
fromConnection:(AVCaptureConnection *)connection
{
// Invokes the callback set above
FrameMetaData *frameMetaData = frameMetaDataGetter();
emitSampleBuffer(sampleBuffer, frameMetaData);
}
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
When making a call to https://api.music.apple.com/v1/me/library/artists to get a user's library artists, it returns the following (as an example):
[
{
id: 'r.FCwruQb',
type: 'library-artists',
href: '/v1/me/library/artists/r.FCwruQb?l=en-US',
attributes: { name: 'A Great Big World' }
},
{
id: 'r.7VSWOgj',
type: 'library-artists',
href: '/v1/me/library/artists/r.7VSWOgj?l=en-US',
attributes: { name: 'Aaliyah' }
},
...
]
If I try and use an artist id from that retuned data to look up additional information about the artist by calling https://api.music.apple.com/v1/catalog/us/artists/{id}, it fails.
User Library Artists don't seem to equal Catalog Artists.
It'd be great if there was a way to use these interchangeably. Am I missing something?
A bit of a novice to app development here but I have a paid developer account, I have registered the identifier for MusicKit on the developer website (using the bundle identifier I've selected in Xcode) but the option to add MusicKit as a capability is not available in Xcode?
I've manually updated the certificates, closed the app and reopened it, started a new project and tried with a different demo project?
Apologies if I am missing something obvious but could someone help me get this capability added?
Session player regions populate blank, with no sound media when tracks or regions are created.
I am working to update a live blog in Apple News. As far as I know there is an update endpoint to update a content in Apple News. Is there any feature in Apple News to trigger an event when the original content updated and pull the updated content?
When I try to send a DRM-protected video via Airplay to an Apple TV, the license request is made twice instead of once as it normally does on iOS.
We only allow one request per session for security reasons, this causes the second request to fail and the video won't play.
We've tested DRM-protected videos without token usage limits and it works, but this creates a security hole in our system.
Why does it request the license twice in function: func contentKeySession(_ session: AVContentKeySession, didProvide keyRequest: AVContentKeyRequest)?
Is there a way to prevent this?
After Picture-in-Picture is opened on the camera interface, the custom UI cannot be displayed. Is there any way to make the custom UI visible? If custom UI cannot be displayed, how do teleprompter-type apps in the store manage to show custom teleprompter text within the camera?
Currently, I am using the Broadcast UploadExtension function to obtain samplebuffer data through APP Group and IPC (based on the local Unix Domain Socket) The screen recording data transmission method of the domain socket is transmitted to the APP. However, when the APP goes back to the background to view videos in the album or other audio and video, the data transmission stops and the APP cannot obtain the screen recording data. I would like to ask how to solve this problem. I suspect that the system has suspended the extended screen recording
Topic:
Media Technologies
SubTopic:
Video
Hi all,
i can successfully match music using shazamkit on Apple using SwiftUI, a simple app that let user to load an audio file and exctracts the relative match, while i am unable to match music using shamzamkit on Android. I am trying to make the same simple app but i cannot match music as i get MATCH_ATTEMPT_FAILED every time i try to. I don't know what i am doing wrong but the shazam part in the kotlin Android code is in this method :
suspend fun processAudioFileInBackground(
filePath: String,
developerTokenProvider: DeveloperTokenProvider
) = withContext(Dispatchers.IO) {
val bufferSize = 1024 * 1024
val audioFile = FileInputStream(filePath)
val byteBuffer = ByteBuffer.allocate(bufferSize)
byteBuffer.order(ByteOrder.LITTLE_ENDIAN)
var bytesRead: Int
while (audioFile.read(byteBuffer.array()).also { bytesRead = it } != -1) {
val signatureGenerator = (ShazamKit.createSignatureGenerator(AudioSampleRateInHz.SAMPLE_RATE_44100) as ShazamKitResult.Success).data
signatureGenerator.append(byteBuffer.array(), bytesRead, System.currentTimeMillis())
val signature = signatureGenerator.generateSignature()
println("Signature: ${signature.durationInMs}")
val catalog = ShazamKit.createShazamCatalog(developerTokenProvider, Locale.ENGLISH)
val session = (ShazamKit.createSession(catalog) as ShazamKitResult.Success).data
val matchResult = session.match(signature)
println("MatchResult : $matchResult")
setMatchResult(matchResult)
byteBuffer.clear()
}
audioFile.close()
}
I noticed that changing Locale in catalog creation results in different result as i get NoMatch without exception. Can you please help me with this?
Topic:
Media Technologies
SubTopic:
Audio
Hello, my company is developing a product that will send data to/from the phone over cable and Wi-Fi. I have three questions:
Do we need an MFi authentication chip in our product if we plan to send video and commands to the iPhone/iPad over USB or Lightning cable?
Likewise, do we need an MFI authentication chip for communication over Wi-Fi? (Informal research suggests that the answer is no to this one.)
And, do we even still need MFI certification at all for Wi-Fi comms? (We are not using HomeKit.)
Thank you!
Topic:
Media Technologies
SubTopic:
Photos & Camera
When creating and activating AVPictureInPictureController on iPhone 11 running iOS 18.x, the main screen viewport unexpectedly changes from the native 375×812 logical points to 414×896 points (the size of a different device such as iPhone XR/11 Plus). Additionally, a separate UIWindow with zero CGRect is created. This causes UIKit layout calculations, especially related to the keyboard and safeAreaInsets, to malfunction and results in issues like keyboard clipping and general UI misalignment. The problem appears tied specifically to iOS 18+ behavior and does not manifest on earlier iOS versions or other devices consistently.
Steps to Reproduce:
Run the app on iPhone 11 with iOS 18.x (including the latest minor updates).
Instantiate and start an AVPictureInPictureController during app runtime.
Observe that UIScreen.main.bounds changes from 375×812 (native iPhone 11 size) to 414×896.
Notice a secondary UIWindow appears with frame CGRectZero.
Interact with text inputs that cause the keyboard to appear.
The keyboard is clipped or partially obscured, causing UI usability issues.
Layout elements dependent on UIScreen.main.bounds or safeAreaInsets behave incorrectly.
Expected Behavior:
UIScreen.main.bounds should not dynamically change upon PiP controller creation. The coordinate space and viewport should remain accurate to device native dimensions. The keyboard and UI layout should adjust properly with respect to the actual on-screen size and safe areas.
Actual Behavior:
UIScreen.main.bounds changes to 414×896 upon PiP controller creation on iPhone 11 iOS 18+.
A zero-rect secondary UIWindow is created, impacting layout queries.
Keyboard clipping and UI layout bugs occur.
The app viewport and coordinate space are inconsistent with device hardware.
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.
I am working on an app which plays audio - https://youtu.be/VbAfUk_eYl0?si=nJg5ayy2faWE78-g - and one of the features is, on restart, if you had paused playback of a file at the time the app was previously shut down (or were playing one at the time of shutdown), the paused state and position in the file is restored exactly as it was, on restart.
The functionality works. However, it seems impossible to get the "now playing" information in iOS into the right state to reflect that via the MediaPlayer API. On restart, handlers are attached to the play/pause/togglePlayPause actions on MPRemoteCommandCenter.shared(), and the map of media info is updated on MPNowPlayingInfoCenter.default().nowPlayingInfo.
What happens is that iOS's media view shows the audio as playing and offers a pause button - even though the play action is enabled and the pause action is disabled.
Once playback has been initiated (my workaround is to have the pause action toggle the play state, since otherwise you wouldn't be able to initiate playback from controls in a car without initiating it once from a device first).
I've created a simplified white-noise-player demo to illustrate the problem - simply build and deploy it, and then start the app, lock your device and look at the playback controls on the lock screen. It will show a pause button - same behavior I've described.
https://github.com/timboudreau/ios-play-pause-demo
I've tried a few things to narrow down the source of the issue - for example, thinking that not MPNowPlayingInfoPropertyPlaybackProgress and MPMediaItemPropertyPlaybackDuration might be the culprit (since the system interpolates elapsed time and it's recommended to update those properties infrequently) on startup might do the trick, but the result is the same, just without a duration or progress shown.
What governs this behavior, and is there some way to explicitly tell the media player API your current state is paused?
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?
I'm developing a video capture app using AVFoundation, designed specifically for use on a boat pylon to record slalom water skiing. This setup involves considerable vibration.
As you may know, the OIS that Apple began adding to lenses since the iPhone 7 is actually very problematic in high vibration circumstances, ironically creating very shaky video, whereas lenses without OIS produce perfectly stable video. Because of this, up until iPhone 14, the solution for my app was simply to use the Selfie lens, which did not have OIS.
Starting with iPhone 14 through iPhone 16 (non-Pro models), technical specs suggest the selfie lens still does not include OIS. However, I’m still seeing the same kind of shaky video behavior I see on OIS-equipped lenses. The one hardware change I see in this camera module is the addition of PDAF (Phase Detection Autofocus), so that is my best guess as to what is causing the unstable video.
1- Does that make any sense - that in high vibration settings, PDAF could create unstable video in the same way that OIS does? Or could it be something else that was changed between the iPhone 13 and 14 Selfie lens?
Thinking that the issue was PDAF, I figured that if I enabled my app to set a Manual Focus level, that ought to circumvent PDAF (expecting that if a lens is manually focusing, it can’t also be autofocusing via PDAF).
However, even with manual focus locked via AVCaptureDevice in my app, on the Selfie lens of an iPhone 16, the video still comes out very shaky, basically unusable. I also tested with the built-in Apple Camera app (using the press-and-hold to lock focus and exposure) and another 3rd party camera app to lock focus, all with the same results, so it's not that my app just isn't correctly doing manual focus.
So I'm stuck with these questions:
2- Does the selfie camera on iPhones 14–16 use PDAF even when focus is set to locked/manual mode?
3- Is there any way in AVFoundation to disable or suppress PDAF during video recording (e.g., a flag, device format setting, or private API)?
4- Is PDAF behavior or suppression documented or controllable via AVCaptureDevice or any related class?
5- If no control of PDAF is available, are there any best practices for stabilizing or smoothing this effect programmatically?
Note that I also have set my app to use the most aggressive form of stabilization available, so it defaults to .cinematicExtendedEnhanced, if that’s not available, then .cinematicExtended, etc. On the 16 Selfie lens, it is using .cinematicExtended. As an additional question:
6- Would those be the most appropriate stabilization settings for a high vibration environment, and if not, what would be best?
Hi, I’ve been experiencing a strange issue with video playback on my iPhone. While watching videos, the image will suddenly shift it becomes more greyish, then sometimes briefly goes black, and then returns to normal bright quality. This can happen multiple times during a single video.
This is not limited to the Photos app. I’ve seen it happen:
In the Photos app when playing videos I recorded myself
In Snapchat when watching videos sent by others
Occasionally in other social media apps as well
Additional details:
HDR Video is turned off
Apple ProRes is turned off
Tried both 4K 60fps and 4K 30fps
Camera format set to “Most Compatible”
Low Power Mode is off
Issue happens whether the phone is cool or warm
Doesn’t seem related to the video file itself the same file exported to another device looks fine all the way through
These exact same videos play back completely normally on my iPad with no brightness or contrast shifts at all
I’m currently on the iOS 17 public beta, but this issue was happening before I installed the beta as well, so it’s not beta-specific
It almost feels like the display or system is switching between different brightness/contrast profiles mid playback, regardless of the app.
Has anyone else experienced this, and is there a way to disable this behavior so the brightness and color stay consistent during video playback?
Thanks in advance!