Dive into the world of video on Apple platforms, exploring ways to integrate video functionalities within your iOS,iPadOS, macOS, tvOS, visionOS or watchOS app.

Video Documentation

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Adding AVCaptureMovieFileOutput and AVCaptureVideoDataOutput with ProRes422
Adding both AVCaptureMovieFileOutput and AVCaptureVideoDataOutput is supported in AVCaptureSession as seen in documentation (copied snippet below) but then when AVCaptureDevice is configured with ProRes422 codec, it fails unless one of the two outputs is removed from the capture session. It is very much reproducible on iPhone 14 pro running iOS 26.0. Prior to iOS 16, you can add an AVCaptureVideoDataOutput and an AVCaptureMovieFileOutput to the same session, but only one may have its connection active. If you attempt to enable both connections, the system chooses the movie file output as the active connection and disables the video data output’s connection. For apps that link against iOS 16 or later, this restriction no longer exists.
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Nov ’25
General iOS/iPadOS 26 decoding bug: MP4 unexpectedly hangs, video image frozen, audio goes on
Playback of any kind of HD H.264 MP4 files (720p, 50fps) could randomly cause a stalled image. Playback does not stop in such a case. Image is frozen/stalled. Audio goes on. Timeline goes on. By tapping play/pause or scrubbing in the timeline, the playback recovers. It could also happen, if you are scrubbing in the timeline, especially to areas not loaded already (progressive MP4 download). Behaviour is always the same: image is stalled/frozen, audio goes on. To reproduce: use example project https://developer.apple.com/documentation/AVKit/playing-video-content-in-a-standard-user-interface Example file: https://www.keepinmind.info/test.mp4
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Nov ’25
How to dynamically update an existing AVComposition when users add a new custom video clip?
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
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310
Nov ’25
Attaching color properties to CVPixelBufferRef
I believe this should work: CFMutableDictionaryRef attrs = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); CFDictionaryAddValue(attrs, kCVImageBufferColorPrimariesKey, kCVImageBufferColorPrimaries_ITU_R_709_2); CFDictionaryAddValue(attrs, kCVImageBufferTransferFunctionKey, kCVImageBufferTransferFunction_ITU_R_709_2); CFDictionaryAddValue(attrs, kCVImageBufferYCbCrMatrixKey, kCVImageBufferYCbCrMatrix_ITU_R_709_2); CVPixelBufferRef pixelBuffer = NULL; CVPixelBufferCreate(kCFAllocatorDefault, width, height, kCVPixelFormatType_32ARGB, attrs, &pixelBuffer); assert(CFDictionaryGetCount(CVBufferGetAttachments(pixelBuffer, kCVAttachmentMode_ShouldPropagate)) > 0); But that last assert fails, so it appears the color info does not get attached. kCVImageBufferColorPrimariesKey and the others are not one of the keys listed under BufferAttributeKeys, but I think they're supposed to be allowed because they're listed by CMVideoFormatDescriptionGetExtensionKeysCommonWithImageBuffers(). I'm hoping that putting the color matrix info in there will control how AVAssetWriter converts the RGB to YCbCr.
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Nov ’25
AVCaptureSession setting preset has no effect if HDR configured with AVCaptureVideoDataOutput
I want to confirm if this is a bug or a programming error. Very easy to reproduce it by modifying AVCam sample code. Steps to reproduce: Add AVCaptureVideoDataOutput to AVCaptureSession, no need to set delegate in AVCam sample code (CaptureService actor) private let videoDataOutput = AVCaptureVideoDataOutput() and then in configureSession method, add the following line try addOutput(videoDataOutput) if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) { videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_420YpCbCr8BiPlanarFullRange] } And next modify set HDR method: /// Sets whether the app captures HDR video. func setHDRVideoEnabled(_ isEnabled: Bool) { // Bracket the following configuration in a begin/commit configuration pair. captureSession.beginConfiguration() defer { captureSession.commitConfiguration() } do { // If the current device provides a 10-bit HDR format, enable it for use. if isEnabled, let format = currentDevice.activeFormat10BitVariant { try currentDevice.lockForConfiguration() currentDevice.activeFormat = format currentDevice.unlockForConfiguration() isHDRVideoEnabled = true if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange) { videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange] } } else { captureSession.sessionPreset = .high isHDRVideoEnabled = false if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_32BGRA) { print("Setting sdr pixel format \(kCVPixelFormatType_32BGRA)") videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_32BGRA] } try currentDevice.lockForConfiguration() currentDevice.activeColorSpace = .sRGB currentDevice.unlockForConfiguration() } } catch { logger.error("Unable to obtain lock on device and can't enable HDR video capture.") } The problem now is toggling HDR on and off no longer works in video mode. If after setting HDR on, you set HDR to off, active format of device does not change (setting sessionPreset has no effect). This does not happen if video data output is not added to session. Is there any workaround available?
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Nov ’25
VTFrameRateConversionConfiguration don't support 640x480
hello, I'm using VideoTololbox VTFrameRateConversionConfiguration to perform frame interpolation: https://developer.apple.com/documentation/videotoolbox/vtframerateconversionconfiguration?language=objc ,when using 640x480 vidoe input, I got error: Error ! Invalid configuration [VEEspressoModel] build failure : flow_adaptation_feature_extractor_rev2.espresso.net. Configuration: landscape640x480 [EpsressoModel] Cannot load Net file flow_adaptation_feature_extractor_rev2.espresso.net. Configuration: landscape640x480 Error: failed to create FRCFlowAdaptationFeatureExtractor for usage 8 Failed to switch (0x12c40e140) [usage:8, 1/4 flow:0, adaptation layer:1, twoStage:0, revision:2, flow size (320x240)]. Could not init FlowAdaptation initFlowAdaptationWithError fail tried 2048x1080 is ok.
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Nov ’25
Changing Frame Rate of External Display on iPad
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!
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Dec ’25
FPS not able to do > 30 fps for Pro and ProMax models only
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.
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Dec ’25
VideoPlayer crashes on Archive build
I have found that following code runs without issue from Xcode, either in Debug or Release mode, yet crashes when running from the binary produced by archiving - i.e. what will be sent to the app store. import SwiftUI import AVKit @main struct tcApp: App { var body: some Scene { WindowGroup { VideoPlayer(player: nil) } } } This is the most stripped down code that shows the issue. One can try and point the VideoPlayer at a file and the same issue will occur. I've attached the crash log: Crash log Please note that this was seen with Xcode 26.2 and MacOS 26.2.
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Dec ’25
AVPlayerViewController volume slider UI changes but audio output level remains constant
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];
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Dec ’25
is the output frame rate of a CMIOExtension rounded or capped?
I made a CMIOExtension (a virtual camera) which generates its own output, for use in our in-house software testing. I wanted to make a video source with 29.97, 30, 59.94 and 60fps output. To this end, I created a CMIOExtensionDeviceSource which creates a CMIOExtensionDevice with one CMIOExtensionStreamSource with various stream formats contained in [CMIOExtensionStreamFormat], including one with both maxFrameDuration and minFrameDuration = CMTimeMake(value: 1000, timescale: 30000) and another with both maxFrameDuration and minFrameDuration = CMTimeMake(value: 1001, timescale: 30000) I've held off on the creation of the 59.94/60fps source for now until this problem is resolved. my virtual camera works, it produces a signal, but when I examine its associated AVCaptureDevice in the debugger, I find (lldb) po self.captureDevice?.formats[0].videoSupportedFrameRateRanges[0].maxFrameDuration ▿ Optional<CMTime> ▿ some : CMTime - value : 1000000 - timescale : 30000000 ▿ flags : CMTimeFlags - rawValue : 1 - epoch : 0 I get the same value, 1000000/30000000, or exactly 30fps, for all the formats of my AVCaptureDevice. Is there something I'm doing wrong, or do CMIOExtensionDevices always round the frame rates? I can't force CoreMediaIO to produce frames at exactly my desired frame interval, but I'd like to ensure that the average frame rate is my desired rate. How can I do that? Frame emission is governed by a repeating DispatchSourceTimer with a repeat time specified in nanoseconds with the TimerFlags set to 'strict'.
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AVPlayerView. Internal constraints conflicts
I’m getting Auto Layout constraint conflict warnings related to AVPlayerView in my project. I’ve reproduced the issue on macOS Tahoe 26.2. The conflict appears to originate inside AVPlayerView itself, between its internal subviews, rather than in my own layout code. This issue can be easily reproduced in an empty project by simply adding an AVPlayerView as a subview using the code below. class ViewController: NSViewController { override func viewDidLoad() { super.viewDidLoad() let playerView = AVPlayerView() view.addSubview(playerView) } } After presenting that view controller, the following Auto Layout constraint conflict warnings appear in the console: Conflicting constraints detected: <decode: bad range for [%@] got [offs:346 len:1057 within:0]>. Will attempt to recover by breaking <decode: bad range for [%@] got [offs:1403 len:81 within:0]>. Unable to simultaneously satisfy constraints: ( "<NSLayoutConstraint:0xb33c29950 H:|-(0)-[AVDesktopPlayerViewContentView:0x10164dce0](LTR) (active, names: '|':AVPlayerView:0xb32ecc000 )>", "<NSLayoutConstraint:0xb33c299a0 AVDesktopPlayerViewContentView:0x10164dce0.right == AVPlayerView:0xb32ecc000.right (active)>", "<NSAutoresizingMaskLayoutConstraint:0xb33c62850 h=--& v=--& AVPlayerView:0xb32ecc000.width == 0 (active)>", "<NSLayoutConstraint:0xb33d46df0 H:|-(0)-[AVEventPassthroughView:0xb33cfb480] (active, names: '|':AVDesktopPlayerViewContentView:0x10164dce0 )>", "<NSLayoutConstraint:0xb33d46e40 AVEventPassthroughView:0xb33cfb480.trailing == AVDesktopPlayerViewContentView:0x10164dce0.trailing (active)>", "<NSLayoutConstraint:0xb33ef8320 NSGlassView:0xb33ed8c00.trailing == AVEventPassthroughView:0xb33cfb480.trailing - 6 (active)>", "<NSLayoutConstraint:0xb33ef8460 NSGlassView:0xb33ed8c00.width == 180 (active)>", "<NSLayoutConstraint:0xb33ef84b0 NSGlassView:0xb33ed8c00.leading >= AVEventPassthroughView:0xb33cfb480.leading + 6 (active)>" ) Will attempt to recover by breaking constraint <NSLayoutConstraint:0xb33ef8460 NSGlassView:0xb33ed8c00.width == 180 (active)> Set the NSUserDefault NSConstraintBasedLayoutVisualizeMutuallyExclusiveConstraints to YES to have -[NSWindow visualizeConstraints:] automatically called when this happens. And/or, set a symbolic breakpoint on LAYOUT_CONSTRAINTS_NOT_SATISFIABLE to catch this in the debugger. Is it system bug or maybe someone knows how to fix that? Thank you.
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