I’m building a macOS video editor that uses AVComposition and AVVideoComposition. Initially, my renderer creates a composition with some default video/audio tracks: @Published var composition: AVComposition? @Published var videoComposition: AVVideoComposition? @Published var playerItem: AVPlayerItem? Then I call a buildComposition() function that inserts all the default video segments. Later in the editing workflow, the user may choose to add their own custom video clip. For this I have a function like: private func handlePickedVideo(_ url: URL) { guard url.startAccessingSecurityScopedResource() else { print("Failed to access security-scoped resource") return } let asset = AVURLAsset(url: url) let videoTracks = asset.tracks(withMediaType: .video) guard let firstVideoTrack = videoTracks.first else { print("No video track found") url.stopAccessingSecurityScopedResource() return } renderer.insertUserVideoTrack(from: asset, track: firstVideoTrack) url.stopAccessingSecurityScopedResource() } What I want to achieve is the same behavior professional video editors provide, after the composition has already been initialized and built, the user should be able to add a new video track and the composition should update live, meaning the preview player should immediately reflect the changes without rebuilding everything from scratch manually. How can I structure my AVComposition / AVMutableComposition and my rendering pipeline so that adding a new clip later updates the existing composition in real time (similar to Final Cut/Adobe Premiere), instead of needing to rebuild everything from zero? You can find a playable version of this entire setup at :- https://github.com/zaidbren/SimpleEditor

Avplayer encapsulates a player. After connecting to an Apple Bluetooth headset, it immediately reports an error. Non-Apple Bluetooth headsets can be played, but currently the issue is that the player works normally in one app but not in another. We are an educational app.

Hello, I requested Fairplay credentials a week ago. Where can I check the status of my request? Thank you very much. The team ID is: 6WZ8SVRYV9

We’re developing an AVFoundation-based video recording app (4K @ 60 fps required for biomechanical analysis). On most devices this works perfectly (iPhone 12/14/15/16 non-Pro models), but on several iPhone Pro models (12 Pro, 13 Pro, 14 Pro, 15 Pro/Pro Max), we consistently get 4K 30 fps recordings—even when the device should support 4K 60 fps on the wide-angle camera. What we observe We configure the session for .hd4K3840x2160. We iterate through AVCaptureDevice.formats and select formats that: have 3840×2160 resolution support ≥60 fps (videoSupportedFrameRateRanges) On some Pro devices, this format search returns no results, even though: The Camera app records 4K60 fine. External references list the wide camera as 4K60 capable. The fallback becomes the device's default 4K30 format, so final files are 3840×2160 @ 30 fps. This happens immediately on app launch (not after heating), so not thermal-related. What we’ve tried Force selecting .builtInWideAngleCamera instead of dual/triple cameras. Disabling HDR (videoHDREnabled = false). Disabling low-light boost. Allowing 59.94 fps formats (in case exact 60.0 isn’t exposed). Logging all videoSupportedFrameRateRanges per format. What we’re seeing in logs On affected Pro devices, the capture device reports only 4K formats with maxFrameRate ≈ 30 fps, despite the hardware being able to do 4K60. Main question Has anyone encountered cases where 4K60 formats are available in the Camera app but not exposed through AVFoundation, especially on Pro models or multi-camera devices? Could HEVC/HDR capability or multi-camera constraints be preventing certain formats from appearing? Are there known conditions where 4K60 formats are hidden unless specific device configuration is applied? Any guidance on reliably locking 4K60 on iPhone Pro models via AVFoundation would be hugely appreciated.

Facing an issue with audio playback using AVPlayerViewController in iOS application. We are using the native player to play recorded audio files. When the AVPlayerViewController appears, the native user interface is displayed correctly, including the playback controls and the volume slider. However, when the user interacts with the volume slider The slider UI moves and responds to touch events. The actual audio output volume does not change. The audio continues playing at the initial volume level regardless of the slider position. We initialize the player and present it modally using the following code: AVPlayerViewController *avController = [[AVPlayerViewController alloc] init]; avController.player = [AVPlayer playerWithURL:videoURL]; // Setting initial volume avController.player.volume = 1.0f; avController.modalPresentationStyle = UIModalPresentationOverFullScreen; avController.allowsPictureInPicturePlayback = NO; // Present the controller [self presentViewController:avController animated:YES completion:nil];

Has anyone tried to make an ILPD based AIME file? When I try the resulting AIME switches to USDZ Mesh instead of saving the ILPD Data.

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

We have a Push To Talk application which allow user to record video and audio. When user is recording a video using AVCaptureSession and receive's an Push To Talk call, from moment the Push To Talk call is received the audio in the video which is being captured is stopped while the video capture is still in progress. Here after the PTT call is completed, we have tried restarting the audio session, there are no errors that are getting printed but we still don't see the audio getting restarted in video capture. We have also tried to add a new input for AVCaptureSession we are receiving error that is resulting in video capture stopping, error mentioned below: [OS-PLT] [CameraManager] Movie file finished with error: Error Domain=AVFoundationErrorDomain Code=-11818 "Recording Stopped" UserInfo={AVErrorRecordingSuccessfullyFinishedKey=true, NSLocalizedDescription=Recording Stopped, NSLocalizedRecoverySuggestion=Stop any other actions using the recording device and try again., AVErrorRecordingFailureDomainKey=1, NSUnderlyingError=0x3026bff60 {Error Domain=NSOSStatusErrorDomain Code=-16414 "(null)"}}, success We have also raised a Feedback Ticket on same: https://feedbackassistant.apple.com/feedback/16050598

Hi, I am recording video using my app. And setting up fps also using below code. But sometime video is being recorded using 20 FPS. Can someone please let me know what I am doing wrong? private func eightBitVariantOfFormat() -> AVCaptureDevice.Format? { let activeFormat = self.videoDeviceInput.device.activeFormat let fpsToBeSupported: Int = 60 debugPrint("fpsToBeSupported - \(fpsToBeSupported)" as AnyObject) let allSupportedFormats = self.videoDeviceInput.device.formats debugPrint("all formats - \(allSupportedFormats)" as AnyObject) let activeDimensions = CMVideoFormatDescriptionGetDimensions(activeFormat.formatDescription) debugPrint("activeDimensions - \(activeDimensions)" as AnyObject) let filterBasedOnDimensions = allSupportedFormats.filter({ (CMVideoFormatDescriptionGetDimensions($0.formatDescription).width == activeDimensions.width) && (CMVideoFormatDescriptionGetDimensions($0.formatDescription).height == activeDimensions.height) }) if filterBasedOnDimensions.isEmpty { // Dimension not found. Required format not found to handle. debugPrint("Dimension not found" as AnyObject) return activeFormat } debugPrint("filterBasedOnDimensions - \(filterBasedOnDimensions)" as AnyObject) let filterBasedOnMaxFrameRate = filterBasedOnDimensions.compactMap({ format in let videoSupportedFrameRateRanges = format.videoSupportedFrameRateRanges if !videoSupportedFrameRateRanges.isEmpty { let contains = videoSupportedFrameRateRanges.contains(where: { Int($0.maxFrameRate) >= fpsToBeSupported }) if contains { return format } else { return nil } } else { return nil } }) debugPrint("allFormatsToBeSupported - \(filterBasedOnMaxFrameRate)" as AnyObject) guard !filterBasedOnMaxFrameRate.isEmpty else { debugPrint("Taking default active format as nothing found when filtered using desired FPS" as AnyObject) return activeFormat } var formatToBeUsed: AVCaptureDevice.Format! if let four_two_zero_v = filterBasedOnMaxFrameRate.first(where: { CMFormatDescriptionGetMediaSubType($0.formatDescription) == kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange}) { // 'vide'/'420v' formatToBeUsed = four_two_zero_v } else { // Take the first one from above array. formatToBeUsed = filterBasedOnMaxFrameRate.first } do { try self.videoDeviceInput.device.lockForConfiguration() self.videoDeviceInput.device.activeFormat = formatToBeUsed self.videoDeviceInput.device.activeVideoMinFrameDuration = CMTimeMake(value: 1, timescale: Int32(fpsToBeSupported)) self.videoDeviceInput.device.activeVideoMaxFrameDuration = CMTimeMake(value: 1, timescale: Int32(fpsToBeSupported)) if videoDeviceInput.device.isFocusModeSupported(.continuousAutoFocus) { self.videoDeviceInput.device.focusMode = AVCaptureDevice.FocusMode.continuousAutoFocus } self.videoDeviceInput.device.unlockForConfiguration() } catch let error { debugPrint("\(error)" as AnyObject) } return formatToBeUsed }

Hi, I am recording a video at 240 FPS within my application and saving it to the Photos app. The recorded video retains 240 FPS in the Photos app. However, after trimming the video using the Photos app and importing it back into my app, the FPS is reduced to 30 FPS. Steps to Reproduce: Record a video inside the application at 240 FPS. Save the recorded video to the Photos app. Verify that the video retains 240 FPS in the Photos app. Trim the video using the built-in Photos app editor. Import the trimmed video back into the application. The FPS of the imported video is now reduced to 30 FPS. Code Used for Importing Video: I am using the following code to fetch the video from the Photos app: let options: PHVideoRequestOptions = PHVideoRequestOptions() options.version = .current // Using `.original` preserves FPS, but I need `.current` for other changes options.deliveryMode = .highQualityFormat options.isNetworkAccessAllowed = true PHImageManager.default().requestAVAsset(forVideo: self, options: options) { (avAsset, audioMix, info) in if let urlAsset = avAsset as? AVURLAsset { completionHandler(urlAsset.url, self) } else { self.askForOriginal(completionHandler: completionHandler) } } Observations: The original video retains 240 FPS until it is trimmed in the Photos app. After trimming, the FPS automatically drops to 30 FPS when imported back into the app. If I use options.version = .original, the FPS is preserved, but I need .current to apply other modifications. Questions: Is this an expected behavior of PHImageManager when requesting a video with options.version = .current? Is there a way to preserve the original FPS while still using .current? Are there any workarounds to extract the trimmed video without FPS reduction? Any insights or solutions would be greatly appreciated. Thanks in advance!

We are using AVAssetDownloadURLSession to download content with multiple audio tracks. Still, we are facing an issue where only one audio language is being downloaded, despite explicitly requesting multiple audio languages. However, all subtitle variants are being downloaded successfully. Issue Details: Observed Behaviour: When initiating a download using AVAssetDownloadURLSession, only one audio track (Hindi, in this case) is downloaded, even though the content contains multiple audio tracks. Expected Behaviour: All requested audio tracks should be downloaded, similar to how subtitle variants are successfully downloaded. Please find sample app implementation details: https://drive.google.com/file/d/1DLcBGNnuWFYsY0cipzxpIHqZYUDJujmN/view?usp=sharing Manifest file for the asset looks something like below #EXTM3U #EXT-X-VERSION:6 #EXT-X-INDEPENDENT-SEGMENTS #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="A1",NAME="Hindi",LANGUAGE="hi",URI="indexHindi/Hindi.m3u8",AUTOSELECT=YES,DEFAULT=YES #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="A2",NAME="Bengali",LANGUAGE="bn",URI="indexBengali/Bengali.m3u8",AUTOSELECT=YES,DEFAULT=YES #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="A3",NAME="Kannada",LANGUAGE="kn",URI="indexKannada/Kannada.m3u8",AUTOSELECT=YES,DEFAULT=YES #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="A4",NAME="Malayalam",LANGUAGE="ml",URI="indexMalayalam/Malayalam.m3u8",AUTOSELECT=YES,DEFAULT=YES #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="A5",NAME="Tamil",LANGUAGE="ta",URI="indexTamil/Tamil.m3u8",AUTOSELECT=YES,DEFAULT=YES #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="A6",NAME="Telugu",LANGUAGE="te",URI="indexTelugu/Telugu.m3u8",AUTOSELECT=YES,DEFAULT=YES #EXT-X-STREAM-INF:BANDWIDTH=832196,AVERAGE-BANDWIDTH=432950,RESOLUTION=640x360,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A1",SUBTITLES="subs" index-4k360p/360p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=832196,AVERAGE-BANDWIDTH=432950,RESOLUTION=640x360,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A2",SUBTITLES="subs" index-4k360p/360p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=832196,AVERAGE-BANDWIDTH=432950,RESOLUTION=640x360,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A3",SUBTITLES="subs" index-4k360p/360p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=832196,AVERAGE-BANDWIDTH=432950,RESOLUTION=640x360,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A4",SUBTITLES="subs" index-4k360p/360p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=832196,AVERAGE-BANDWIDTH=432950,RESOLUTION=640x360,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A5",SUBTITLES="subs" index-4k360p/360p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=832196,AVERAGE-BANDWIDTH=432950,RESOLUTION=640x360,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A6",SUBTITLES="subs" index-4k360p/360p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1317051,AVERAGE-BANDWIDTH=607343,RESOLUTION=854x480,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A1",SUBTITLES="subs" index-4k480p/480p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1317051,AVERAGE-BANDWIDTH=607343,RESOLUTION=854x480,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A2",SUBTITLES="subs" index-4k480p/480p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1317051,AVERAGE-BANDWIDTH=607343,RESOLUTION=854x480,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A3",SUBTITLES="subs" index-4k480p/480p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1317051,AVERAGE-BANDWIDTH=607343,RESOLUTION=854x480,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A4",SUBTITLES="subs" index-4k480p/480p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1317051,AVERAGE-BANDWIDTH=607343,RESOLUTION=854x480,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A5",SUBTITLES="subs" index-4k480p/480p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1317051,AVERAGE-BANDWIDTH=607343,RESOLUTION=854x480,FRAME-RATE=25.0,CODECS="hvc1.2.4.L93.b0,mp4a.40.2",AUDIO="A6",SUBTITLES="subs" index-4k480p/480p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1715498,AVERAGE-BANDWIDTH=717018,RESOLUTION=1024x576,FRAME-RATE=25.0,CODECS="hvc1.2.4.L123.b0,mp4a.40.2",AUDIO="A1",SUBTITLES="subs" index-4k576p/576p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1715498,AVERAGE-BANDWIDTH=717018,RESOLUTION=1024x576,FRAME-RATE=25.0,CODECS="hvc1.2.4.L123.b0,mp4a.40.2",AUDIO="A2",SUBTITLES="subs" index-4k576p/576p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1715498,AVERAGE-BANDWIDTH=717018,RESOLUTION=1024x576,FRAME-RATE=25.0,CODECS="hvc1.2.4.L123.b0,mp4a.40.2",AUDIO="A3",SUBTITLES="subs" index-4k576p/576p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1715498,AVERAGE-BANDWIDTH=717018,RESOLUTION=1024x576,FRAME-RATE=25.0,CODECS="hvc1.2.4.L123.b0,mp4a.40.2",AUDIO="A4",SUBTITLES="subs" index-4k576p/576p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1715498,AVERAGE-BANDWIDTH=717018,RESOLUTION=1024x576,FRAME-RATE=25.0,CODECS="hvc1.2.4.L123.b0,mp4a.40.2",AUDIO="A5",SUBTITLES="subs" index-4k576p/576p.m3u8 #EXT-X-STREAM-INF:BANDWIDTH=1715498,AVERAGE-BANDWIDTH=717018,RESOLUTION=1024x576,FRAME-RATE=25.0,CODECS="hvc1.2.4.L123.b0,mp4a.40.2",AUDIO="A6",SUBTITLES="subs" index-4k576p/576p.m3u8 #EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,LANGUAGE="en",URI="subtitle_en/sub_en_vtt.m3u8"

No video is playing and the same error is coming. I have tried everything by resetting. Please get an update as soon as possible. error-The operation couldn't be completed. (CoreMediaErrorDomain error -42709.)

operation couldn't be completed. (CoreMediaErrorDomain error -42709.) this error shows after update He has been coming here for the last 10 days. Please! please correct it as soon as possible

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

I have been using SDAVAssetExportSession to compress videos in an app I am building, everything goes very smoothly until I have my new Iphone16, on the device, the spatial audio in camera setting is turned on by default, then the SDAVAssetExportSession starts to fail. I know it has something to do with audioSetting. the current setting is something like this: exportSession.audioSettings = [ AVFormatIDKey: kAudioFormatMPEG4AAC, AVNumberOfChannelsKey: 2, AVSampleRateKey: 44100, AVEncoderBitRateKey: 128000 ] And also, this is passed to the underlying object AVAssetReader or AVAssetWriter. I am not experienced in this area, and I really had a hard time trying to figure out. Does anyone know how to set up AVAssetReader or AVAssetWriter to process video with spatial audio tracks ? thanks in advance.

I'm using an iPhone 15 Pro, which has switched from Lightning to USB Type-C. My iOS version is 18.3. According to Apple's documentation, AVCaptureDevice.DeviceType should support external device types. 🔗 Apple's Official Documentation: https://developer.apple.com/documentation/avfoundation/avcapturedevice/devicetype-swift.struct/external The documentation clearly states that iPadOS 17.0+ and iOS 17.0+ support external devices. However, in my actual tests: On iPhone, discoverySession does not detect any external devices. On iPad, discoverySession can detect external devices without any issues. My Question: Does iPhone USB-C actually support external devices (e.g., UVC cameras)? If not, why does Apple's documentation claim that iOS 17 supports external devices instead of specifying iPadOS 17 only?

It's 2025, and I see that trends in video storage and streaming have changed significantly. Nowadays, CDN combined with domain-based video protection is the most popular solution. Does anyone have more insights into this technology or real-world experience with it?

We're experiencing significant issues with AVPlayer when attempting to play partially downloaded HLS content in offline mode. Our app downloads HLS video content for offline viewing, but users encounter the following problems: Excessive Loading Delay: When offline, AVPlayer attempts to load resources for up to 60 seconds before playing the locally available segments Asset Loss: Sometimes AVPlayer completely loses the asset reference and fails to play the video on subsequent attempts Inconsistent Behavior: The same partially downloaded asset might play immediately in one session but take 30+ seconds in another Network Activity Despite Offline Settings: Despite configuring options to prevent network usage, AVPlayer still appears to be attempting network connections These issues severely impact our offline user experience, especially for users with intermittent connectivity. Technical Details Implementation Context Our app downloads HLS videos for offline viewing using AVAssetDownloadTask. We store the downloaded content locally and maintain a dictionary mapping of file identifiers to local paths. When attempting to play these videos offline, we experience the described issues. Current Implementation Here's our current implementation for playing the videos: - (void)presentNativeAvplayerForVideo:(Video *)video navContext:(NavContext *)context { NSString *localPath = video.localHlsPath; if (localPath) { NSURL *videoURL = [NSURL URLWithString:localPath]; NSDictionary *options = @{ AVURLAssetPreferPreciseDurationAndTimingKey: @YES, AVURLAssetAllowsCellularAccessKey: @NO, AVURLAssetAllowsExpensiveNetworkAccessKey: @NO, AVURLAssetAllowsConstrainedNetworkAccessKey: @NO }; AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:options]; AVPlayerViewController *playerViewController = [[AVPlayerViewController alloc] init]; NSArray *keys = @[@"duration", @"tracks"]; [asset loadValuesAsynchronouslyForKeys:keys completionHandler:^{ dispatch_async(dispatch_get_main_queue(), ^{ AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:asset]; AVPlayer *player = [AVPlayer playerWithPlayerItem:playerItem]; playerViewController.player = player; [player play]; }); }]; playerViewController.modalPresentationStyle = UIModalPresentationFullScreen; [context presentViewController:playerViewController animated:YES completion:nil]; } } Attempted Solutions We've tried several approaches to mitigate these issues: Modified Asset Options: NSDictionary *options = @{ AVURLAssetPreferPreciseDurationAndTimingKey: @NO, // Changed to NO AVURLAssetAllowsCellularAccessKey: @NO, AVURLAssetAllowsExpensiveNetworkAccessKey: @NO, AVURLAssetAllowsConstrainedNetworkAccessKey: @NO, AVAssetReferenceRestrictionsKey: @(AVAssetReferenceRestrictionForbidRemoteReferenceToLocal) }; Skipped Asynchronous Key Loading: AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:asset automaticallyLoadedAssetKeys:nil]; Modified Player Settings: player.automaticallyWaitsToMinimizeStalling = NO; [playerItem setPreferredForwardBufferDuration:2.0]; Added Network Resource Restrictions: playerItem.canUseNetworkResourcesForLiveStreamingWhilePaused = NO; Used File URLs Instead of HTTP URLs where possible Despite these attempts, the issues persist. Expected vs. Actual Behavior Expected Behavior: AVPlayer should immediately begin playback of locally available HLS segments When offline, it should not attempt to load from network for more than a few seconds Once an asset is successfully played, it should be reliably available for future playback Actual Behavior: AVPlayer waits 10-60 seconds before playing locally available segments Network activity is observed despite all network-restricting options Sometimes the player fails completely to play a previously available asset Behavior is inconsistent between playback attempts with the same asset Questions: What is the recommended approach for playing partially downloaded HLS content offline with minimal delay? Is there a way to force AVPlayer to immediately use available local segments without attempting to load from the network? Are there any known issues with AVPlayer losing references to locally stored HLS assets? What diagnostic steps would you recommend to track down the specific cause of these delays? Does AVFoundation have specific timeouts for offline HLS playback that could be configured? Any guidance would be greatly appreciated as this issue is significantly impacting our user experience. Device Information iOS Versions Tested: 14.5 - 18.1 Device Models: iPhone 12, iPhone 13, iPhone 14, iPhone 15 Xcode Version: 15.3-16.2.1

I am trying to achieve an animated gradient effect that changes values over time based on the current seconds. I am also using AVPlayer and AVMutableVideoComposition along with custom instruction and class to generate the effect. I didn't want to load any video file, but rather generate a custom video with my own set of instructions. I used Metal Compute shaders to generate the effects and make the video to be 20 seconds. However, when I run the code, I get a frozen player with the gradient applied, but when I try to play the video, I get this warning in the console :- Visual isTranslatable: NO; reason: observation failure: noObservations Here is the screenshot :- My entire code :- import AVFoundation import Metal class GradientVideoCompositorTest: NSObject, AVVideoCompositing { var sourcePixelBufferAttributes: [String: Any]? = [ kCVPixelBufferPixelFormatTypeKey as String: kCVPixelFormatType_32BGRA ] var requiredPixelBufferAttributesForRenderContext: [String: Any] = [ kCVPixelBufferPixelFormatTypeKey as String: kCVPixelFormatType_32BGRA ] private var renderContext: AVVideoCompositionRenderContext? private var metalDevice: MTLDevice! private var metalCommandQueue: MTLCommandQueue! private var metalLibrary: MTLLibrary! private var metalPipeline: MTLComputePipelineState! override init() { super.init() setupMetal() } func setupMetal() { guard let device = MTLCreateSystemDefaultDevice(), let queue = device.makeCommandQueue(), let library = try? device.makeDefaultLibrary(), let function = library.makeFunction(name: "gradientShader") else { fatalError("Metal setup failed") } self.metalDevice = device self.metalCommandQueue = queue self.metalLibrary = library self.metalPipeline = try? device.makeComputePipelineState(function: function) } func renderContextChanged(_ newRenderContext: AVVideoCompositionRenderContext) { renderContext = newRenderContext } func startRequest(_ request: AVAsynchronousVideoCompositionRequest) { guard let outputPixelBuffer = renderContext?.newPixelBuffer(), let metalTexture = createMetalTexture(from: outputPixelBuffer) else { request.finish(with: NSError(domain: "com.example.gradient", code: -1, userInfo: nil)) return } var time = Float(request.compositionTime.seconds) renderGradient(to: metalTexture, time: time) request.finish(withComposedVideoFrame: outputPixelBuffer) } private func createMetalTexture(from pixelBuffer: CVPixelBuffer) -> MTLTexture? { var texture: MTLTexture? let width = CVPixelBufferGetWidth(pixelBuffer) let height = CVPixelBufferGetHeight(pixelBuffer) let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor( pixelFormat: .bgra8Unorm, width: width, height: height, mipmapped: false ) textureDescriptor.usage = [.shaderWrite, .shaderRead] CVPixelBufferLockBaseAddress(pixelBuffer, .readOnly) if let textureCache = createTextureCache(), let cvTexture = createCVMetalTexture(from: pixelBuffer, cache: textureCache) { texture = CVMetalTextureGetTexture(cvTexture) } CVPixelBufferUnlockBaseAddress(pixelBuffer, .readOnly) return texture } private func renderGradient(to texture: MTLTexture, time: Float) { guard let commandBuffer = metalCommandQueue.makeCommandBuffer(), let commandEncoder = commandBuffer.makeComputeCommandEncoder() else { return } commandEncoder.setComputePipelineState(metalPipeline) commandEncoder.setTexture(texture, index: 0) var mutableTime = time commandEncoder.setBytes(&mutableTime, length: MemoryLayout<Float>.size, index: 0) let threadsPerGroup = MTLSize(width: 16, height: 16, depth: 1) let threadGroups = MTLSize( width: (texture.width + 15) / 16, height: (texture.height + 15) / 16, depth: 1 ) commandEncoder.dispatchThreadgroups(threadGroups, threadsPerThreadgroup: threadsPerGroup) commandEncoder.endEncoding() commandBuffer.commit() } private func createTextureCache() -> CVMetalTextureCache? { var cache: CVMetalTextureCache? CVMetalTextureCacheCreate(kCFAllocatorDefault, nil, metalDevice, nil, &cache) return cache } private func createCVMetalTexture(from pixelBuffer: CVPixelBuffer, cache: CVMetalTextureCache) -> CVMetalTexture? { var cvTexture: CVMetalTexture? let width = CVPixelBufferGetWidth(pixelBuffer) let height = CVPixelBufferGetHeight(pixelBuffer) CVMetalTextureCacheCreateTextureFromImage( kCFAllocatorDefault, cache, pixelBuffer, nil, .bgra8Unorm, width, height, 0, &cvTexture ) return cvTexture } } class GradientCompositionInstructionTest: NSObject, AVVideoCompositionInstructionProtocol { var timeRange: CMTimeRange var enablePostProcessing: Bool = true var containsTweening: Bool = true var requiredSourceTrackIDs: [NSValue]? = nil var passthroughTrackID: CMPersistentTrackID = kCMPersistentTrackID_Invalid init(timeRange: CMTimeRange) { self.timeRange = timeRange } } func createGradientVideoComposition(duration: CMTime, size: CGSize) -> AVMutableVideoComposition { let composition = AVMutableComposition() let instruction = GradientCompositionInstructionTest(timeRange: CMTimeRange(start: .zero, duration: duration)) let videoComposition = AVMutableVideoComposition() videoComposition.customVideoCompositorClass = GradientVideoCompositorTest.self videoComposition.renderSize = size videoComposition.frameDuration = CMTime(value: 1, timescale: 30) // 30 FPS videoComposition.instructions = [instruction] return videoComposition } #include <metal_stdlib> using namespace metal; kernel void gradientShader(texture2d<float, access::write> output [[texture(0)]], constant float &time [[buffer(0)]], uint2 id [[thread_position_in_grid]]) { float2 uv = float2(id) / float2(output.get_width(), output.get_height()); // Animated colors based on time float3 color1 = float3(sin(time) * 0.8 + 0.1, 0.6, 1.0); float3 color2 = float3(0.12, 0.99, cos(time) * 0.9 + 0.3); // Linear interpolation for gradient float3 gradientColor = mix(color1, color2, uv.y); output.write(float4(gradientColor, 1.0), id); }

I was advised to post here by a Code-Level Support representative. Below will be a copy of my initial issue report, and my minimally reproductive test project can be found at the following GitHub repository URL... https://github.com/PierceLBrooks/vtUudSeiNalCmake DESCRIPTION OF PROBLEM When encoding H264 video codec data using the VTCompressionSession API facilities available through the VideoToolbox framework on MacOS, the resultant bitstream will invariably include Unregistered User Data SEI NAL units that carry the UUID "47564adc-5c4c-433f-94ef-c5113cd143a8". The proprietary decoders we are working with currently struggle with filtering out these NAL units. Can you explain what purpose this serves, what the meaning of the byte-wise unit payloads are, and which configuration settings the VideoToolbox encoder instance specifically depends upon for triggering the insertion of them? STEPS TO REPRODUCE 1. Invoke the instantiation of a new VideoToolbox H264 encoder object by calling VTCompressionSessionCreate with appropriate configuration flags. 2. Push frames through the encoder, receiving their encoded byte buffer counterparts through an asynchronous callback. 3. Write that encoded data to some buffer which will contain the totality of the encoder's output. 4. Inspect the NAL units of the initial portion of this output bitstream buffer. 5. Observe the presence of at least one Unregistered User Data SEI NAL unit carrying the "47564adc-5c4c-433f-94ef-c5113cd143a8" UUID near the beginning of the output segment.