the problem is when using HLS live stream with AVPlayer on iOS/ tvOS the player chooses first highest bandwidth then slowly steps down to lowest (within 1-3min) and eventually steps up again then repeats to step down. the AVPlayer error log sends events: errorStatusCode: -12888, errorDomain: Optional("CoreMediaErrorDomain"), errorComment: Optional("The operation couldn't be completed. (CoreMediaErrorDomain error -12888 - Playlist File unchanged for longer than 1.5 * target duration we use standard segments in CMAF format, 2sec duration #EXTM3U #EXT-X-VERSION:6 #EXT-X-TARGETDURATION:2 #EXT-X-MEDIA-SEQUENCE:147065903 #EXT-X-MAP:URI="video_1_4660000_init.mp4?device_profile=cmaf_cbcs_verimatrix_cei%26seg_size=2%26cmaf=2" #EXT-X-PROGRAM-DATE-TIME:2025-04-30T12:51:07 #EXTINF:2.000, video_1_4660000_t17460174670001555.mp4?device_profile=cmaf_cbcs_verimatrix_cei%26seg_size=2%26cmaf=2 #EXTINF:2.000, video_1_4660000_t17460174690001555.mp4?device_profile=cmaf_cbcs_verimatrix_cei%26seg_size=2%26cmaf=2 #EXTINF:2.000, video_1_4660000_t17460174710001555.mp4?device_profile=cmaf_cbcs_verimatrix_cei%26seg_size=2%26cmaf=2 when using 6sec segments the player stays stable at highest bandwidth. is there a way to avoid this error? in AVPlayer or HLS configuration?

In my app I use AVAssetReaderTrackOutput to extract PCM audio from a user-provided video or audio file and display it as a waveform. Recently a user reported that the waveform is not in sync with his video, and after receiving the video I noticed that the waveform is in fact double as long as the video duration, i.e. it shows the audio in slow-motion, so to speak. Until now I was using CMFormatDescription.audioStreamBasicDescription.mSampleRate which for this particular user video returns 22'050. But in this case it seems that this value is wrong... because the audio file has two audio channels with different sample rates, as returned by CMFormatDescription.audioFormatList.map({ $0.mASBD.mSampleRate }) The first channel has a sample rate of 44'100, the second one 22'050. If I use the first sample rate, the waveform is perfectly in sync with the video. The problem is given by the fact that the ratio between the audio data length and the sample rate multiplied by the audio duration is 8, double the ratio for the first audio file (4). In the code below this ratio is given by Double(length) / (sampleRate * asset.duration.seconds) When commenting out the line with the sampleRate variable definition in the code below and uncommenting the following line, the ratios for both audio files are 4, which is the expected result. I would expect audioStreamBasicDescription to return the correct sample rate, i.e. the one used by AVAssetReaderTrackOutput, which (I think) somehow merges the stereo tracks. The documentation is sparse, and in particular it’s not documented whether the lower or higher sample rate is used; in this case, it seems like the higher one is used, but audioStreamBasicDescription for some reason returns the lower one. Does anybody know why this is the case or how I should extract the sample rate of the produced PCM audio data? Should I always take the higher one? I created FB19620455. let openPanel = NSOpenPanel() openPanel.allowedContentTypes = [.audiovisualContent] openPanel.runModal() let url = openPanel.urls[0] let asset = AVURLAsset(url: url) let assetTrack = asset.tracks(withMediaType: .audio)[0] let assetReader = try! AVAssetReader(asset: asset) let readerOutput = AVAssetReaderTrackOutput(track: assetTrack, outputSettings: [AVFormatIDKey: Int(kAudioFormatLinearPCM), AVLinearPCMBitDepthKey: 16, AVLinearPCMIsBigEndianKey: false, AVLinearPCMIsFloatKey: false, AVLinearPCMIsNonInterleaved: false]) readerOutput.alwaysCopiesSampleData = false assetReader.add(readerOutput) let formatDescriptions = assetTrack.formatDescriptions as! [CMFormatDescription] let sampleRate = formatDescriptions[0].audioStreamBasicDescription!.mSampleRate //let sampleRate = formatDescriptions[0].audioFormatList.map({ $0.mASBD.mSampleRate }).max()! print(formatDescriptions[0].audioStreamBasicDescription!.mSampleRate) print(formatDescriptions[0].audioFormatList.map({ $0.mASBD.mSampleRate })) if !assetReader.startReading() { preconditionFailure() } var length = 0 while assetReader.status == .reading { guard let sampleBuffer = readerOutput.copyNextSampleBuffer(), let blockBuffer = sampleBuffer.dataBuffer else { break } length += blockBuffer.dataLength } print(Double(length) / (sampleRate * asset.duration.seconds))

I am unable to find any clearcut documentation on configuring AVCaptureSession pipeline to capture video with proResRAW codec type, which is 16 bit format. Is it supported only with AVCaptureMovieFileOutput or one can have AVCaptureVideoDataOutput emitting 16-bit sample buffers that can be vended to AVAssetWriter?

My app want Converting iphone12 HDR Video to SDR，to edit。 follow the doc Apple-HDR-Convert. My code setting the pixBuffAttributes        [pixBuffAttributes setObject:(id)(kCVImageBufferYCbCrMatrix_ITU_R_709_2) forKey:(id)kCVImageBufferYCbCrMatrixKey];       [pixBuffAttributes setObject:(id)(kCVImageBufferColorPrimaries_ITU_R_709_2) forKey:(id)kCVImageBufferColorPrimariesKey];       [pixBuffAttributes setObject:(id)kCVImageBufferTransferFunction_ITU_R_709_2 forKey:(id)kCVImageBufferTransferFunctionKey];       playerItemOutput = [[AVPlayerItemVideoOutput alloc] initWithPixelBufferAttributes:pixBuffAttributes]; but I get the playerItemOutput's output buffer   CFTypeRef colorAttachments = CVBufferGetAttachment(pixelBuffer, kCVImageBufferYCbCrMatrixKey, NULL);     CFTypeRef colorPrimaries = CVBufferGetAttachment(pixelBuffer, kCVImageBufferColorPrimariesKey, NULL);     CFTypeRef colorTransFunc = CVBufferGetAttachment(pixelBuffer, kCVImageBufferTransferFunctionKey, NULL);      NSLog(@"colorAttachments = %@", colorAttachments);     NSLog(@"colorPrimaries = %@", colorPrimaries);     NSLog(@"colorTransFunc = %@", colorTransFunc); log output: colorAttachments = ITU_R_2020 colorPrimaries = ITU_R_2020 colorTransFunc = ITU_R_2100_HLG pixBuffAttributes setting output format invalid，please help！

Hello, I have been running into issues with setting nowPlayingInfo information, specifically updating information for CarPlay and the CPNowPlayingTemplate. When I start playback for an item, I see lock screen information update as expected, along with the CarPlay now playing information. However, the playing items are books with collections of tracks. When I select a new track(chapter) within the book, I set the MPMediaItemPropertyTitle to the new chapter name. This change is reflected correctly on the lock screen, but almost never appears correctly on the CarPlay CPNowPlayingTemplate. The previous chapter title remains set and never updates. I see "Application exceeded audio metadata throttle limit." in the debug console fairly frequently. From that a I figured that I need to minimize updates to the nowPlayingInfo dictionary. What I did: I store the metadata dictionary in a local dictionary and only set values in the main nowPlayingInfo dictionary when they are different from the current value. I kick off the nowPlayingInfo update via a task that initially sleeps for around 2 seconds (not a final value, just for my current testing). If a previous Task is active, it gets cancelled, so that only one update can happen within that time window. Neither of these things have been sufficient. I can switch between different titles entirely and the information updates (including cover art). But when I switch chapters within a title, the MPMediaItemPropertyTitle continues to get dropped. I know the value is getting set, because it updates on the lock screen correctly. In total, I have 12 keys I update for info, though with the above changes, usually 2-4 of them actually get updated with high frequency. I am running out of ideas to satisfy the throttling thresholds to accurately display metadata. I could use some advice. Thanks.

I’ve been struggling with a very frustrating issue using the new iOS 26 Swift Concurrency APIs for video processing. My pipeline reads frames using AVAssetReader, processes them via CIContext (Lanczos upscale), and then appends the result to an AVAssetWriter using the new PixelBufferReceiver. The Problem: The execution randomly stops at the ]await append(...)] call. The task suspends and never resumes. It is completely unpredictable: It might hang on the very first run, or it might work fine for 4-5 runs and then hang on the next one. It is independent of video duration: It happens with 5-second clips just as often as with long videos. No feedback from the system: There is no crash, no error thrown, and CPU usage drops to zero. The thread just stays in the suspended state indefinitely. If I manually cancel the operation and restart the VideoEngine, it usually starts working again for a few more attempts, which makes me suspect some internal resource exhaustion or a deadlock between the GPU context and the writer's input. The Code: Here is a simplified version of my processing loop: private func proccessVideoPipeline( readerOutputProvider: AVAssetReaderOutput.Provider<CMReadySampleBuffer<CMSampleBuffer.DynamicContent>>, pixelBufferReceiver: AVAssetWriterInput.PixelBufferReceiver, nominalFrameRate: Float, targetSize: CGSize ) async throws { while !Task.isCancelled, let payload = try await readerOutputProvider.next() { let sampleBufferInfo: (imageBuffer: CVPixelBuffer?, presentationTimeStamp: CMTime) = payload.withUnsafeSampleBuffer { sampleBuffer in return (sampleBuffer.imageBuffer, sampleBuffer.presentationTimeStamp) } guard let currentPixelBuffer = sampleBufferInfo.imageBuffer else { throw AsyncFrameProcessorError.missingImageBuffer } guard let pixelBufferPool = pixelBufferReceiver.pixelBufferPool else { throw NSError(domain: "PixelBufferPool", code: -1, userInfo: [NSLocalizedDescriptionKey: "No pixel buffer pool available"]) } let newPixelBuffer = try pixelBufferPool.makeMutablePixelBuffer() let newCVPixelBuffer = newPixelBuffer.withUnsafeBuffer({ $0 }) try upscale(currentPixelBuffer, outputPixelBuffer: newCVPixelBuffer, targetSize: targetSize ) let presentationTime = sampleBufferInfo.presentationTimeStamp try await pixelBufferReceiver.append(.init(unsafeBuffer: newCVPixelBuffer), with: presentationTime) } } Does anyone know how to fix it?

Please consider adding the ability to programatically download Premium and Enhanced voices. At the moment it is extremely inconvenient for our users, as they have to navigate to settings themselves to download voices. Our app relies heavily on SpeechSynthesis integration, and it would greatly benefit from this feature. FB16307193

Hello, As far as I know and in all of my testing there is no way for a user or a developer to change the frame rate of the video output on iPadOS. If you connect an iPad via a USB Hub or a USB to HDMI Adaptor and then connect it to an external monitor it will output at 59.94fps. I have a video app where a user monitors live video at 25fps and 30fps, they often output to an external display and there are times when the external display will stutter due to the mismatch in frame rate, ie. using 25fps and outputting at 59.94fps. I thought it was impossible to change the video output frame rate, then in V3.1 of the Blackmagic Camera App I saw an interesting change in their release notes: ‘Support for HDMI Monitoring at Sensor Rate and Resolution’ This means there is some way to modify it, not sure if this is done via a Private API that Apple has allowed Blackmagic to use. If so, how can we access this or is there a way to enable this that is undocumented? Thanks!

Hi, I understand that AVPlayer/AVFoundation doesn’t natively play MPEG-DASH manifests (.mpd) today, while HLS is supported and widely documented by Apple. I’m not asking for roadmap commitments, but I’d like to understand whether there is any publicly documented rationale for not supporting DASH/MPD in AVFoundation (e.g., technical constraints, platform integration, DRM ecosystem, power/performance considerations, etc.). Questions: Is there any Apple statement / documentation explaining why DASH (MPD) isn’t supported in AVFoundation? Is Apple’s recommended approach still “provide HLS for Apple clients” (potentially sharing CMAF segments and generating separate manifests)? If there’s no public rationale, is filing Feedback Assistant the best channel for requesting MPD playback support? Thanks!

Hi, I’m trying to better understand how AVAssetDownloadConfiguration selects video variants when downloading HLS content for offline playback. Suppose I have an HLS master playlist (.m3u8) that contains several video variants defined with #EXT-X-STREAM-INF. For example, the master playlist may contain multiple video streams like this: Same resolution, different BANDWIDTH Or different resolutions (for example 720p, 1080p, etc.) My question is: How many video variants are actually downloaded when using AVAssetDownloadConfiguration without specifying any variantQualifiers? In other words: If the master playlist contains multiple video variants, will the download task fetch only one variant, or multiple variants? Does the behavior differ depending on whether the variants differ only by BANDWIDTH or also by RESOLUTION? What I observed in testing In my tests, I always end up with only one video variant downloaded, specifically the one with the highest BANDWIDTH parameter. In the m3u8 files I tested, all video variants had identical parameters (resolution, codec, frame rate, etc.) and differed only by the BANDWIDTH attribute in the master playlist. However, when inspecting the downloaded .movpkg, I noticed something interesting in boot.xml. It lists two video streams: one with complete="true" (the one with highest bandwidth) another with complete="no" (the one with lowest bandwidth) I actually had 3 video streams listed in m3u8, but the one with middle bandwidth wasn't listed in boot.xml file at all. There are also additional streams for audio and subtitles in boot.xml file. This made me wonder whether the system initially attempts to download another video variant (possibly a lower bitrate one), but then switches to the highest-quality variant and only completes that one. Additional question about variantQualifiers If I provide a predicate such as: NSPredicate(format: "peakBitRate > 0") which should theoretically match all variants, will the download task attempt to download all matching video variants, or will it still select only one? Summary So the main questions are: Without variantQualifiers, does AVAssetDownloadConfiguration always download a single video variant, and if so, how is it chosen? Does the behavior differ if variants have different resolutions vs only different bitrates? When a predicate matches multiple variants, can multiple video variants actually be downloaded in a single .movpkg? Why might boot.xml list multiple video streams when only one appears to be fully downloaded? Any clarification on the intended behavior would be greatly appreciated. Thanks!

Hi guys, I noticed that Apple created a really engaging visual effect for browsing spatial videos in the app. The video appears embedded in glass panel with glowing edges and even shows a parallax effect as you move around. When I tried to display the stereo video using RealityView, however, the video entity always floats above the panel. May I ask how does VisionOS implement this effect? Is there any approach to achieve this effect or example code I can use in my own code. Thanks!

I have a question regarding the behavior of AVAudioSession.sharedInstance().outputVolume. Observed behavior: When the app is in the foreground, I read audioSession.outputVolume (for example, 0.1). The app is then moved to the background. While the app is in the background, the user changes the system volume using the hardware buttons (for example, to 0.5). When the app returns to the foreground, audioSession.outputVolume still reports the previous value (0.1). From my testing, outputVolume only seems to update when the system volume is changed while the app is in the foreground. Volume changes made while the app is in the background are not reflected when the app returns to the foreground. Questions: According to Apple’s documentation for AVAudioSession.outputVolume: “The systemwide output volume set by the user.” https://developer.apple.com/documentation/avfaudio/avaudiosession/outputvolume However, based on our testing on iOS 18.6.2 and iOS 18.1, the observed behavior seems to differ from this description. Questions: The documentation states that outputVolume represents the system-wide volume set by the user. In our testing, the value does not reflect volume changes made while the app is in the background and only updates when the app is in the foreground.Is this the expected behavior of AVAudioSession.outputVolume? Is there any other recommended way in Swift to retrieve the current system volume that reflects user changes made both while the app is in the foreground and while it is in the background? Any clarification on the intended behavior or recommended handling would be greatly appreciated.

AVAudioFormat has no Swift concurrency annotations but the documentation states "Instances of this class are immutable." This made me always assume it was safe to pass AVAudioFormat instances around. Is this the case? If so can it be marked as Sendable? Am I missing something?

AlarmKit custom sounds are universally broken in iOS 26.0 stable - instead of playing your custom sound, it plays a system error/timeout beep. I've spent days investigating why custom sounds result in what sounds like an error beep (like when you cancel an operation or hit a timeout) instead of the actual audio file. I can now prove this is an Apple bug, not implementation error. Evidence: Test 1: My Implementation Followed Apple's documentation exactly Tried both bundle and Library/Sounds (as documented) Result: System error beep (not my audio) Test 2: Professional Apps Tested ADHDAlarms (popular AlarmKit example by jacobsapps) https://github.com/jacobsapps/ADHDAlarms Their airhorn.mp3 custom sound: same error beep (not an airhorn) Their default sound: works perfectly Test 3: Device Testing Physical iPhone (iOS 26.0 - 23A341): broken iOS Simulator: broken Not device-specific Files are found correctly, but the actual audio file is never played. Instead, you hear what sounds like a system error/cancellation tone. What I've Eliminated Not a Library/Sounds vs Bundle issue (both broken) Not a file format issue (.mp3, .caf, .m4a all broken) Not an implementation issue (professional apps broken too) Not a device issue (simulator and device both broken) Not a file size issue (5KB to 2MB all broken) The Documentation Lie: Apple's docs for AlertConfiguration.AlertSound.named(_:) state: "Choose a file that's in your app's main bundle or the Library/Sounds folder" https://developer.apple.com/documentation/activitykit/alertconfiguration/alertsound/named(_:) Both locations are broken. Tested on: iOS 26.0 (23A341), Xcode 26.0.1, Swift 6.2 Impact: This affects any app trying to: Provide personalized wake-up sounds Use custom alarm tones Create meditation/sleep apps Differentiate from default iOS alarms Current Status: Multiple bug reports filed: FB19900024, FB18237648, FB19779004 Apple engineer claimed "fixed in latest beta" in August Still broken in iOS 26.0 stable (September) Workaround: None that I know of. You must use .default sound. For apps needing custom audio, play it with AVAudioPlayer after the alarm fires and user opens the app. Question: Has ANYONE gotten custom AlarmKit sounds working in iOS 26.0 stable? If so, plzzz help I'd be so grateful.

Hello everyone, I'm looking for a definitive clarification on how to completely disable all video stabilization, including the hardware OIS, using AVFoundation. The goal is to achieve a completely raw, unstabilized video feed, which is crucial when using external equipment like gimbals to avoid conflicting stabilization motions. My research points to using the AVCaptureConnection property preferredVideoStabilizationMode and setting it to AVCaptureVideoStabilizationMode.off. The documentation for the .off case states: A mode that doesn’t stabilize video capture. This description is slightly ambiguous. It's unclear whether this only affects software-level stabilization (EIS, EIS+OIS, etc) or if it guarantees the complete deactivation of the physical OIS module. For professional video applications, this is a critical distinction. So, I'd like to ask the community: Has anyone been able to definitively confirm that setting preferredVideoStabilizationMode to .off also disables the hardware OIS? Are there any known tests or documentation that prove this behavior? Is there an alternative or more direct method to ensure the OIS module is physically inactive during video capture? What is the community's best practice for ensuring absolutely no stabilization is applied to the video pipeline? Any insights or shared experiences on this topic would be greatly appreciated. Thank you!

Is it possible to stream video from a UVC (USB Video Class) camera on an iPhone 15? If so, are there any specific hardware or software requirements to enable this functionality?

Please include the line below in follow-up emails for this request. Case-ID: 11089799 When using AVSpeechUtterance and setting it to play in Mandarin, if Siri is set to Cantonese on iOS 18, it will be played in Cantonese. There is no such issue on iOS 17 and 16. 1.let utterance = AVSpeechUtterance(string: textView.text) let voice = AVSpeechSynthesisVoice(language: "zh-CN") utterance.voice = voice 2.In the phone settings, Siri is set to Cantonese

Hi everyone, We're encountering an unexpected issue with our iPhone-only camera app: 👉 TimeMark - Photo Proof https://apps.apple.com/us/app/timemark-photo-proof/id6446071834 Problem Description: Our app uses a full-screen camera view via AVCaptureSession. In some cases reported by users, the camera fails immediately upon app launch, and we receive this interruption reason: AVCaptureSessionInterruptionReasonVideoDeviceNotAvailableWithMultipleForegroundApps According to the Apple documentation https://developer.apple.com/documentation/avfoundation/avcapturesession/interruptionreason/videodevicenotavailablewithmultipleforegroundapps?language=objc , this interruption typically occurs when the app is running in a multi-app layout such as Slide Over, Split View, or Picture in Picture — all of which are iPad-only features. However, this issue is being reported on iPhones, and our app does not support iPad at all. Also noted in the documentation: "Given your present AVCaptureSession configuration, the session may only be run if your app occupies the full screen." Additional Context: The issue occurs immediately on app launch, before the user can interact with the camera. We don’t enable multitaskingCameraAccessEnabled. We are 100% sure this is happening on iPhone, not iPad. It’s hard to reproduce; users report it happening sporadically. Locally, we tried playing Picture-in-Picture videos (e.g., Safari/YouTube) before launching our app, but we could not reproduce the issue. Questions: Why is this interruption reason occurring on iPhone, which doesn’t officially support Slide Over or Split View? Could this be caused by some system-level multitasking or resource contention (e.g., Picture in Picture from FaceTime or Safari)? Would enabling multitaskingCameraAccessEnabled help prevent this issue on iPhone, even though it's designed for iPad? Enabling multitaskingCameraAccessEnabled seems to require enabling UIBackgroundModes → voip. Would adding this background mode cause any App Store review risk or rejection if our app doesn't actually use VoIP functionality? Any help, insight, or suggestions would be greatly appreciated. Thanks in advance!

For iPhones 16 and below, orientation is applied in UIImage or CIImage, but not for iPhone 17. The camera is front-facing, and it uses Vision to capture facial images. Thanks for your help.

Hi I know it's possible to play equirectangular VR180 video either SBS or MV-HEVC. And for fisheye video, the only way I know is to convert it into an AIVU for playback. Is there any way to directly play fisheye video using AVPlayer? Thanks a lot!