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

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Non-sendable type AVMediaSelectionGroup
Hi all, we try migrate project to Swift 6 Project use AVPlayer in MainActor Selection audio and subtitiles not work Task { @MainActor in let group = try await item.asset.loadMediaSelectionGroup(for: AVMediaCharacteristic.audible) get error: Non-sendable type 'AVMediaSelectionGroup?' returned by implicitly asynchronous call to nonisolated function cannot cross actor boundary and second example `if #available(iOS 15.0, *) { player?.currentItem?.asset.loadMediaSelectionGroup(for: AVMediaCharacteristic.audible, completionHandler: { group, error in if error != nil { return } if let groupWrp = group { DispatchQueue.main.async { self.setupAudio(groupWrp, audio: audioLang) } } }) }` get error: Sending 'groupWrp' risks causing data races
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500
Feb ’25
​​Can VideoToolbox properly decode HEVC bitstreams when a single frame is split into multiple slice NALUs?​
I am currently developing an HEVC player using VideoToolbox on an iOS device. I have successfully created an HEVC decoder that receives HEVC streams from our custom image capture and encoding device, and it can decode and display images properly. However, when my image capture and encoding device configures the encoder to output HEVC streams with ​​fragmented NALUs​​ (i.e., an I-frame or P-frame is split and stored across multiple slice NALUs), the iOS decoder can be initialized successfully but fails to decode and output images. ​​Can VideoToolbox properly decode HEVC bitstreams when a single frame is split into multiple slice NALUs?​​ Key Observations: ​​1. Single-NALU frames​​ work fine. ​​2. Multi-NALU frames​​ (sliced I/P-frames) cause decoding failure. 3. The decoder session is created successfully (VTDecompressionSessionCreate returns no error).
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131
May ’25
Missing Depth Frames When Recording with AVCaptureVideoDataOutputSampleBufferDelegate/AVCaptureDataOutputSynchronizerDelegate and AVAssetWriter
I’ve tried both AVCaptureVideoDataOutputSampleBufferDelegate (captureOutput) and AVCaptureDataOutputSynchronizerDelegate (dataOutputSynchronizer), but the number of depth frames and saved timestamps is significantly lower than the number of frames in the .mp4 file written by AVAssetWriter. In my code, I save: Timestamps for each frame to a metadata file Depth frames to a binary file Video to an .mp4 file If I record a 4-second video at 30fps, the .mp4 file correctly plays for 4 seconds, but the number of stored timestamps and depth frames is much lower—around 70 frames instead of the expected 120. Does anyone know why this mismatch happens? func dataOutputSynchronizer(_ synchronizer: AVCaptureDataOutputSynchronizer, didOutput synchronizedDataCollection: AVCaptureSynchronizedDataCollection) { // Read all outputs guard let syncedDepthData: AVCaptureSynchronizedDepthData = synchronizedDataCollection.synchronizedData(for: depthDataOutput) as? AVCaptureSynchronizedDepthData, let syncedVideoData: AVCaptureSynchronizedSampleBufferData = synchronizedDataCollection.synchronizedData(for: videoDataOutput) as? AVCaptureSynchronizedSampleBufferData else { // only work on synced pairs return } if syncedDepthData.depthDataWasDropped || syncedVideoData.sampleBufferWasDropped { return } let depthData = syncedDepthData.depthData let depthPixelBuffer = depthData.depthDataMap let sampleBuffer = syncedVideoData.sampleBuffer guard let videoPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer), let formatDescription = CMSampleBufferGetFormatDescription(sampleBuffer) else { return } addToPreviewStream?(CIImage(cvPixelBuffer: videoPixelBuffer)) if !canWrite() { return } // Extract the presentation timestamp (PTS) from the sample buffer let timestamp = CMSampleBufferGetPresentationTimeStamp(sampleBuffer) //sessionAtSourceTime is the first buffer we will write to the file if self.sessionAtSourceTime == nil { //Make sure we don't start recording until the buffer reaches the correct time (buffer is always behind, this will fix the difference in time) guard sampleBuffer.presentationTimeStamp >= self.recordFromTime! else { return } self.sessionAtSourceTime = sampleBuffer.presentationTimeStamp self.videoWriter!.startSession(atSourceTime: sampleBuffer.presentationTimeStamp) } if self.videoWriterInput!.isReadyForMoreMediaData { self.videoWriterInput!.append(sampleBuffer) self.videoTimestamps.append( Timestamp( frame: videoTimestamps.count, value: timestamp.value, timescale: timestamp.timescale ) ) let ddm = depthData.depthDataMap depthCapture.addDepthData(pixelBuffer: ddm, timestamp: timestamp) } }
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Feb ’25
401 Authorization error for Music Feed API
I've established proper authorization for general music api calls, but when I use that same authorization to retrieve metadata for the latest music feeds (see https://developer.apple.com/documentation/applemusicfeed/requesting-a-feed-export), I get a 401 Unauthorized error. As per the documentation, I'm simply issuing a GET against https://api.media.apple.com/v1/feed/album/latest. Are there different entitlements needed for the Music Feed API?
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May ’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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417
Feb ’25
How to write RGB & Depth Frames Without Losing Synchronization
I’m currently working on a project where I capture both depth frames and RGB frames using AVCaptureDataOutputSynchronizer. Depth frames are stored as raw binary data and RGB frames are saved with AVAssetWriter. The issue I’m facing is that AVAssetWriter enforces a fixed framerate, meaning it adds or discards frames to maintain that rate (as I understand it). This causes a desynchronization between the depth and RGB frames, which is a problem because I need each depth frame to be exactly matched with the corresponding RGB frame as they were captured. How can I ensure that the RGB frames are saved without AVAssetWriter modifying the frame count?
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363
Feb ’25
MusicKit playbackTime Accuracy
Hello, Has anyone else experienced variations in the accuracy of the playbackTime value? After a few seconds of playback, the reported time adjusts by a fraction of a second, making it difficult to calculate the actual playbackTime of the audio. This can be recreated by playing a song in MusicKit, recording the start time of the audio, playing for at least 10-20 seconds, and then comparing the playbackTime value to one calculated using the start time of the audio. In my experience this jump occurs after about 10 seconds of playback. Any help would be appreciated. Thanks!
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117
May ’25
Does PHAsset localIdentifier change after device transfer?
Hi, I’m working on a photo backup app. I track the PHAsset localIdentifier to determine which photos have been backed up and which haven’t. Recently, I’ve noticed that two users seem to have experienced the localIdentifier changes after transferring data to a new iPhone using Quick Start. Additionally, others on StackOverflow have mentioned that the localIdentifier sometimes changes after updating the iOS version. https://stackoverflow.com/questions/40094728/phobject-localidentifier-reliability I’d like to confirm the reliability of the localIdentifier after an iOS version upgrade or device transfer. Can I continue using these locally stored localIdentifiers? Or is there another recommended approach, such as using PHCloudIdentifier?
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383
Feb ’25
AirDropped Videos from Photos Save to Files Instead of Photos on Receiving Device
My app allows users to capture and save videos to the Photos app using the following Swift code: PHPhotoLibrary.shared().performChanges { PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: fileURL) } completionHandler: { success, error in Videos are successfully saved to Photos and play correctly. However, users report that when they AirDrop these videos from the Photos app to another device (e.g., iPad to iPhone), the videos are saved in the Files app on the receiving device instead of the Photos app. This issue is more common with higher-resolution videos, such as 2K, recorded in HEVC format at 30 fps. I wasn't able to reproduce the issue locally. I've found a thread in public apple forum: https://discussions.apple.com/thread/255276865?sortBy=rank but I wonder maybe there are some special flags that I should clear or add to my videos (e.g. PHAssetChangeRequest)? Thank you!
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May ’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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568
Feb ’25
PhotosPicker obtains the result information of the selected video
In the AVP project, a selector pops up, only wanting to filter spatial videos. When selecting the material of one of the spatial videos, the selection result returns empty. How can we obtain the video selected by the user and get the path and the URL of the file The code is as follows: PhotosPicker(selection: $selectedItem, matching: .videos) { Text("Choose a spatial photo or video") } func loadTransferable(from imageSelection: PhotosPickerItem) -> Progress { return imageSelection.loadTransferable(type: URL.self) { result in DispatchQueue.main.async { // guard imageSelection == self.imageSelection else { return } print("加载成功的图片集合:(result)") switch result { case .success(let url?): self.selectSpatialVideoURL = url print("获取视频链接:(url)") case .success(nil): break // Handle the success case with an empty value. case .failure(let error): print("spatial错误:(error)") // Handle the failure case with the provided error. } } } }
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May ’25
AVSpeechSynthesizer & Bluetooth Issues
Hello, I have a CarPlay Navigation app and utilize the AVSpeechSynthesizer to speak directions to a user. Everything works great on my CarPlay simulator as well as when plugged into my GMC truck. However, I found out yesterday that one of my users with a Ford truck the audio would cut in an out. After much troubleshooting, I was able to replicate this on my own truck when using Bluetooth to connect to CarPlay. My user was also utilizing Bluetooth. Has anyone else experienced this? Is there a fix to the problem? import SwiftUI import AVFoundation class TextToSpeechService: NSObject, ObservableObject, AVSpeechSynthesizerDelegate { private var speechSynthesizer = AVSpeechSynthesizer() static let shared = TextToSpeechService() override init() { super.init() speechSynthesizer.delegate = self } func configureAudioSession() { speechSynthesizer.delegate = self do { try AVAudioSession.sharedInstance().setCategory(.playback, mode: .voicePrompt, options: [.mixWithOthers, .allowBluetooth]) } catch { print("Failed to set audio session category: \(error.localizedDescription)") } } func speak(_ text: String) { Task(priority: .high) { let speechUtterance = AVSpeechUtterance(string: text) speechUtterance.voice = AVSpeechSynthesisVoice(language: AVSpeechSynthesisVoice.currentLanguageCode()) try AVAudioSession.sharedInstance().setActive(true, options: .notifyOthersOnDeactivation) speechSynthesizer.speak(speechUtterance) } } func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) { Task { stopSpeech() try AVAudioSession.sharedInstance().setActive(false) } } func stopSpeech() { speechSynthesizer.stopSpeaking(at: .immediate) } }
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428
Feb ’25
Crash in Photos framework
Hi This is one of our top crashes. It does not contain any of our code in the stacktrace and we can't reproduce it. Those points make this crash very hard to understand and fix. We know that most of the crashes are happening on iPhone 13 with iOS 18.x.x. Also we see that a lot of cases happen when app goes into background (stacktrace contains -[UIApplication _applicationDidEnterBackground]). 2025-03-04_16-06-00.3670_-0500-6a273c7d5da97f098b5cc24898bb9761dc45208e.crash 2025-03-04_20-21-08.6609_-0500-2c08f640900f8a62c4f8a4f6f2a61feb052e66dd.crash 2025-03-04_20-46-27.7138_+0000-4d7ea89b1b564eda22ca63e708f7ad3909c7b768.crash
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436
Mar ’25
how to enumerate build-in media devices?
Hello, I need to enumerate built-in media devices (cameras, microphones, etc.). For this purpose, I am using the CoreAudio and CoreMediaIO frameworks. According to the table 'Daemon-Safe Frameworks' in Apple’s TN2083, CoreAudio is daemon-safe. However, the documentation does not mention CoreMediaIO. Can CoreMediaIO be used in a daemon? If not, are there any documented alternatives to detect built-in cameras in a daemon (e.g., via device classes in IOKit)? Thank you in advance, Pavel
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92
May ’25
Using the AVPlayer to play encrypted streams causes the system to reboot
When we use AVPlayer to play DRM encrypted streams, it will not play normally under iOS 17.6.1 system version, and there is a high probability of system restart. This is the relevant core error log: error 14:47:53.323369+0800 audiomxd [AirPlayError] carManager_copyProperty_block_invoke:499: got error -12784/0xFFFFCE10 kCMBaseObjectError_PropertyNotFound error 14:47:53.323414+0800 audiomxd [SPEndpointManagerFactory] SidePlay Endpoint Manager creation failed with -72390/0xFFFEE53A error 14:47:53.364949+0800 audiomxd [APBrowserCarSessionHelper] [0xF6AA] [Bonjour/WiFi] Unrecognized ConnectivityHelper event 101 error 14:47:53.375313+0800 audiomxd AddInstanceForFactory: No factory registered for id <CFUUID 0xa5c5118c0> F8BB1C28-BAE8-11D6-9C31-00039315CD46
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249
Mar ’25
Memory leak AVAudioPlayer
Let's consider the following code. I've created an actor that loads a list of .mp3 files from a Bundle and then makes it available for audio reproduction. Unfortunately, I'm experiencing a memory leak. At the play method. player.play() From Instruments I get _malloc_type_malloc_outlined libsystem_malloc.dylib start_wqthread libsystem_pthread.dylib private actor AudioActor { enum Failure: Error { case soundsNotLoaded([AudioPlayerClient.Sound: Error]) } enum Player { case music(AVAudioPlayer) } var players: [Sound: Player] = [:] let bundles: [Bundle] init(bundles: UncheckedSendable<[Bundle]>) { self.bundles = bundles.wrappedValue } func load(sounds: [Sound]) throws { try AVAudioSession.sharedInstance().setActive(true, options: []) var errors: [Sound: Error] = [:] for sound in sounds { guard let url = bundle.url(forResource: sound.name, withExtension: "mp3") else { continue } do { self.players[sound] = try .music(AVAudioPlayer(contentsOf: url)) } catch { errors[sound] = error } } guard errors.isEmpty else { throw Failure.soundsNotLoaded(errors) } } func play(sound: Sound, loops: Int?) throws { guard let player = self.players[sound] else { return } switch player { case let .music(player): player.numberOfLoops = loops ?? -1 player.play() } } func stop(sound: Sound) throws { guard let player = self.players[sound] else { throw Failure.soundsNotLoaded([:]) } switch player { case let .music(player): player.stop() } } }
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101
Mar ’25
3D scanning and 3D model with texture mapping
I am new here and would appreciate help in coding or an explanation what to use in swift for an app which will be able to capture LiDAR scanning and RGB data from taken pictures, generate a 3D mesh, and create .OBJ, .MTL, and .JPEG file set for further manipulation of 3D model. I am able to create from LiDAR scanning 3D mesh and .OBJ file but can not generate .MTL and .JPEG for a texture of 3D model.
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385
Feb ’25
Ducking MusicKit output when playing another sound
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()
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48
Apr ’25