Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.

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How to reduce CMSampleBuffer volume
Hello, Basically, I am reading and writing an asset. To simplify, I am just reading the asset and rewriting it into an output video without any modifications. However, I want to add a fade-out effect to the last three seconds of the output video. I don’t know how to do this. So far, before adding the CMSampleBuffer to the output video, I tried reducing its volume using an extension on CMSampleBuffer. In the extension, I passed 0.4 for testing, aiming to reduce the video's overall volume by 60%. My question is: How can I directly adjust the volume of a CMSampleBuffer? Here is the extension: extension CMSampleBuffer { func adjustVolume(by factor: Float) -> CMSampleBuffer? { guard let blockBuffer = CMSampleBufferGetDataBuffer(self) else { return nil } var length = 0 var dataPointer: UnsafeMutablePointer<Int8>? guard CMBlockBufferGetDataPointer(blockBuffer, atOffset: 0, lengthAtOffsetOut: nil, totalLengthOut: &length, dataPointerOut: &dataPointer) == kCMBlockBufferNoErr else { return nil } guard let dataPointer = dataPointer else { return nil } let sampleCount = length / MemoryLayout<Int16>.size dataPointer.withMemoryRebound(to: Int16.self, capacity: sampleCount) { pointer in for i in 0..<sampleCount { let sample = Float(pointer[i]) pointer[i] = Int16(sample * factor) } } return self } }
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425
May ’25
Is AVPlayerViewController not supported on macCatalyst?
When building an application that can be built on iOS using macCatalyst, a link error like the one below will occur. Undefined symbol: OBJC_CLASS$_AVPlayerViewController The AVPlayerViewController documentation seems to support macCatalyst, but what is the reality? [AVPlayerViewController](https://developer.apple.com/documentation/avkit/avplayerviewcontroller? language=objc) Each version of the environment is as follows. Xcode 16.2 macOS deployment target: macOS 10.15 iOS deployment target: iOS 13.0 Thank you for your support.
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432
Mar ’25
Urdu Language Keyboard Bug
Hello Apple, i've been using ios for many years and never had any issues with urdu language keyboard, but since the new 18.4 beta update some words are not working correctly as it should like a name of my friend who's name is "راعنیہ" but the new updated version cannot type is together and keep seperating like "راعنی ہ" its so frustrating to use like that and its not just one but so many other words that it just cannot do properly also the new font and no gap concept its hurting my eyes so much while reading or even typing.. i hope apple fixes that asap.. thankyou
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488
Feb ’25
ShazamKit android sdk – 16 KB Page Size Support?
Hey, just wonderng if anyone knows whether the sdk for Android will be updated soon to support the new 16 KB memory page size requirement coming with Android 15? Google’s going to require all apps targeting Android 15+ to support it starting November 2025 Has anyone heard anything from Apple or the SDK team about this? Thanks!
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185
May ’25
Apple watch for child
Hi, my daughter was given an Apple Watch due to her grandfather's passing. It is not GPS/cellular, and we cannot connect it to her Apple ID because of this. It doesn't seem right to leave her logged in to his Apple ID, but we are currently out of options. Is there a workaround to this? When I try to set her up from my phone, it tells me that the watch must have GPS/cellular to set it up. Why? Am I missing something?
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146
Jun ’25
All boys wanna access Media Library (sung to All Gurls Wanna Have Fun)
Howdy. I'm trying to access media from a users song library and receive: <ICUserIdentityStoreACAccountBackend: 0x148f8af30> Failed to initialize active account, error=Error Domain=ICError Code=-7013 "Client is not entitled to access account store" UserInfo={NSDebugDescription=Client is not entitled to access account store} I'm told I need to add a Media Library Access Capability. Nothing like this shows up in Xcode under Signing & Capabilities > +Capabilities. Also I can't find anything like this in my account in dev.apple.com. How do I enable myself and a test user using another iPhone device to access my music and their music respectively? Thanks!
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233
Jun ’25
MusicKit API returns 500 Internal Server Error despite valid JWT and setup
My app is properly configured with MusicKit. I've generated a JWT using my valid credentials (Team ID, Key ID, private key), and I’ve ensured the time settings are correct via NTP. When I call: https://api.music.apple.com/v1/catalog/jp/search?term=ado&amp;types=songs I consistently receive a 500 Internal Server Error. The JWT is generated using ES256 with valid iat and exp values. I’ve confirmed the token decodes properly using jwt.io, and it's passed via the Authorization: Bearer header. Things I’ve confirmed: Key ID, Team ID, private key are correct App ID is configured with MusicKit capability JWT is generated and signed correctly macOS time is synced via NTP Used both curl and Python to test — same result Is there anything else I should check on the Apple Developer Console (like App ID, Certificates, or provisioning profile)? Or could this be a backend issue on Apple’s side? Any guidance would be appreciated.
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Nov ’25
AVSpeechSynthesizer read Mandarin as Cantonese(iOS 26 beta 3))
In iOS 26, AVSpeechSynthesizer read Mandarin into Cantonese pronunciation. No matter how you set the language, and change the settings of my phone system, it doesn't work. let utterance = AVSpeechUtterance(string: "你好啊") //let voice = AVSpeechSynthesisVoice(language: "zh-CN") // not work let voice = AVSpeechSynthesisVoice(language: "zh-Hans") // not work too utterance.voice = voice et synth = AVSpeechSynthesizer() synth.speak(utterance)
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Aug ’25
Why does CADisplayLink of an external UIScreen drift in time?
I am using Apple's original Lightning Digital AV-adapter (Lightning-to-HDMI dongle) to connect my iPhone to an external display via a HDMI cable. I need to synchronize rendering with the external display's refresh rate, so I create a new CADisplayLink tied to the external display's UIScreen: UIScreen.screens[externalDisplayIdx].displayLink(withTarget:, selector:). The callback is being called regularly, but with increasing delay relative to the CADisplayLink.timestamp, so the next time the callback is called, I have less and less time to draw the next frame (see the snippet below). Assuming 60 FPS, the value of secondsTillDeadline starts at an arbitrary value in the range of approx -0.0001 to 0.0166667, and then it slowly decreases towards zero (and for a brief period it goes into small negative numbers). Once it reaches zero, it flips back to 0.0166667 and continues to decrease again. This cycle repeats indefinitely. Changing the external display's resolution (UIScreen's mode) or the CADisplayLink's preferredFrameRateRange to a lower FPS does not seem to have any effect on the temporal drifting (even the rate of change seem to be the same). When I create a new CADisplayLink for the iPhone's main screen, the value of secondsTillDeadline is stable, it does not drift and it is very close to 0.0166667, as expected. Is this drift caused by the external monitor or by Apple's Lightning-to-HDMI dongle ...or is the problem somewhere else? Can the drifting be stopped? func onDisplayLinkUpdate(displayLink: CADisplayLink) { // Gradually decreases from 0.01667 to -0.0001, then flips back to 0.01667 and continues to decrease let secondsTillDeadline = displayLink.targetTimestamp - CACurrentMediaTime() }
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Aug ’25
BackgroundAssets `url(for:` throws error for locally available asset
On an iPhone running iOS 26 beta 5, url(for: FilePath("subdir/asset.mov")) most always throws this error: The URL for “subdir/asset.mov” couldn’t be retrieved: “asset.mov” couldn’t be copied to “subdir” because an item with the same name already exists. Yet, contents(at: FilePath("subdir/asset.mov")) always returns Data for a playable AVMovie. How can I avoid this url(for:) error? The asset pack in question is downloaded. The error persists even after pack deletion, redownload, relaunch, and combinations of that. // Assets repo root subdir.aar subdir/asset.mov subdir/asset_thumb.heic subdir/Manifest.json // Manifest.json { "assetPackID": "subdir", "downloadPolicy": { "onDemand": {} }, "fileSelectors": [ { "directory": "subdir", }, ], "platforms": [ "iOS", "visionOS" ] } xcrun ba-package subdir/Manifest.json -o subdir.aar xcrun ba-serve --host 192.168.0.10 -p 443 subdir.aar
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Aug ’25
Metal CIKernel instances with arbitrarily structured data arguments
Hi, In the iOS13 and macOS Catalina release notes it says: Metal CIKernel instances now support arguments with arbitrarily structured data. I've been trying to use this functionality in a CIKernel with mixed results. I'm particularly interested in passing data in the form of a dynamically sized array. It seems to work up to a certain size. Beyond the threshold excessive data is discarded and the kernel becomes unstable. I assume there is some kind of memory alignment issue going on, but I've tried various types in my array and always get a similar result. I have not found any documentation or sample code regarding this. It would be great to know how this is intended to work and what the limitations are. In the forums there are two similar unanswered questions about data arguments, so I'm sure there are a few out there with similar issues. Thanks! Michael
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Oct ’25
How to display artwork images from MusicKit with UIKit?
In SwiftUI there is a built-in component for displaying album artworks called Artwork but there is no equivalent for UIKit. My current approach is to use the .url() method to read image's URL and download the image or read it from the disk but the performance is much worse than it was previously with MPMediaItem's artworkImage method. let artworkQueue = DispatchQueue( label: "MusicKit-ArtworkQueue", qos: .default, attributes: .concurrent ) let artworkSemaphore = DispatchSemaphore(value: 5) extension Song { func artworkImage(for size: CGSize, completion: @escaping (UIImage?) -> Void) { artworkQueue.async { artworkSemaphore.wait() defer { artworkSemaphore.signal() } let imageURL = artwork?.url( width: Int(size.width), height: Int(size.height) ) // I hate doing this as it might very well break in the future guard let imageURL, imageURL.scheme == "musicKit" else { return completion(nil) } guard let imageData = try? Data(contentsOf: imageURL), let image = UIImage(data: imageData) else { return completion(nil) } completion(image) } } } I really dislike this approach because it feels hacky but somewhat works. You might ask what's the semaphore for? Well, without it I could notice that MusicKit was choking and after reading too many artworks at once. Can someone from Apple please provide us with an example on how to use MusicKit with UIKit properly? Ideally (IMO) we would have a method defined on Song and other MusicKit structures that returns the image for us, just like MPMediaItem had the .artwork() method. It would make our lives so much easier.
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1k
Mar ’25
"Remote call timed out" error when trying to play large collection of music items with MusicKit's ApplicationMusicPlayer
I am using MusicKit ApplicationMusicPlayer to play music in my app. Everything works fine as long as I'm not playing large playlists that contain hundreds of songs. When I to play collection of songs that is larger than around 300 I'm always getting the error message saying: "Prepare to play failed" UserInfo={NSDebugDescription=Prepare to play failed, NSUnderlyingError=0x121d42dc0 {Error Domain=MPMusicPlayerControllerErrorDomain Code=9 "Remote call timed out" UserInfo={NSDebugDescription=Remote call timed out}}})) It doesn't matter if songs are downloaded to the device or not. I am aware that there is another initializer for player's queue that accepts Playlist instances but in my app users can choose to sort playlist tracks in different order than the default and that makes using that initializer not feasible for me. I tried everything I could think of, I tried to fall back on MPMusicPlayerController and pass array of MPMusicPlayerPlayParameters to it but the result was the same. typealias QueueEntry = ApplicationMusicPlayer.Queue.Entry let player = ApplicationMusicPlayer.shared let entries: [QueueEntry] = tracks .compactMap { guard let song = $0 as? Song else { return nil } return QueueEntry(song) } Task(priority: .high) { [player] in do { player.queue = .init(entries, startingAt: nil) try await player.play() // prepareToPlay failed } catch { print(error) } }
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680
Mar ’25
Musickit Media player missing output device selection
Hi All, I am working on a DJ playout app (MACOS). The app has a few AVAudioPlayerNode's combined with the ApplicationMusicPlayer from Musickit. I can route the output of the AVaudioPlayer to a hardware device so that the audio files are directed to their own dedicated output on my Mac. The ApplicationMusicPlayer is following the default output and this is pretty annoying. Has anyone found a solution to chain the ApplicationMusicPlayer and get it set to a output device? Thanks Pancras
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598
Feb ’25
AVPlayer error: Too many open files
For some users in production, there's a high probability that after launching the App, using AVPlayer to play any local audio resources results in the following error. Restarting the App doesn't help. issue: [error: Error Domain=AVFoundationErrorDomain Code=-11800 "这项操作无法完成" UserInfo={NSLocalizedFailureReason=发生未知错误(24), NSLocalizedDescription=这项操作无法完成, NSUnderlyingError=0x30311f270 {Error Domain=NSPOSIXErrorDomain Code=24 "Too many open files"}} I've checked the code, and there aren't actually multiple AVPlayers playing simultaneously. What could be causing this?
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434
Feb ’25
SFSpeechRecognizer throws User denied access to speech recognition
I have created an app where you can speak using SFSpeechRecognizer and it will recognize you speech into text, translate it and then return it back using speech synthesis. All locales for SFSpeechRecognizer and switching between them work fine when the app is in the foreground but after I turn off my screen(the app is still running I just turned off the screen) and try to create new recognitionTask it it receives this error inside the recognition task: User denied access to speech recognition. The weird thing about this is it only happens with some languages. The error happens with Croatian or Hungarian locale for speech recognition but doesn't with English or Spanish locale.
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386
Mar ’25
HDR video metadata
On an iOS 18 phone, I use AVCaptureSession to capture HDR with x420 format. The output CMSampleBuffer is HLG colorspace, the propagated attachments contain kCVImageBufferAmbientViewingEnvironmentKey and kCVImageBufferSceneIlluminationKey. Now I use CAMetalLayer to render the CVPixelBuffer to the screen, but the brightness is brighter than AVSampleBufferDisplayLayer. Here is my code. - (void)_updateColorSpaceIfNeed:(CVPixelBufferRef)pixelBuffer { CAMetalLayer *layer = (CAMetalLayer *)_mtkView.layer; if (![layer isKindOfClass:CAMetalLayer.class]) return; layer.wantsExtendedDynamicRangeContent = YES; CFDataRef ambientViewingEnvironment = (CFDataRef)CVBufferCopyAttachment(pixelBuffer, kCVImageBufferAmbientViewingEnvironmentKey, NULL); NSData *data = (__bridge NSData *)ambientViewingEnvironment; if (ambientViewingEnvironment) CFRelease(ambientViewingEnvironment); CAEDRMetadata *metadata = [CAEDRMetadata HLGMetadataWithAmbientViewingEnvironment:data]; // CAEDRMetadata *metadata = [CAEDRMetadata HLGMetadata]; layer.EDRMetadata = metadata; layer.pixelFormat = MTLPixelFormatRGBA16Float; CGColorSpaceRef colorspace = CGColorSpaceCreateWithName(kCGColorSpaceITUR_2100_HLG); layer.colorspace = colorspace; if (colorspace) CGColorSpaceRelease(colorspace); } Why does the CAEDRMetadata class have "HLGMetadataWithAmbientViewingEnvironment:" and "HLGMetadata" methods, but does not provide the "HLGMetadataWithAmbientViewingEnvironment:sceneIllumination" method? I want to know how kCVImageBufferAmbientViewingEnvironmentKey and kCVImageBufferSceneIlluminationKey affect tone mapping. Is there any documentation I can refer to?
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463
Mar ’25