There are significant crash reports coming from iOS 18 users regarding AVKit framework that starts from this line [AVPlayerController _observeValueForKeyPath:oldValue:newValue:] which seems to be coming from iOS internal SDK. There are 2 kinds of crash we found:
UI modification on background thread
From the stack trace it seems like when AVPictureInPictureController is being deallocated and its view is being removed from superview somehow the code is being executed in background thread because there is this line there _AssertAutoLayoutOnAllowedThreadsOnly highlighted before the crash.
But I’ve checked our code that plays around AVPictureInPictureController, in the locations where we would deallocate the object it will always be called on main thread which are insideviewDidLoad and deinit inside UIViewController class. From the log, it seems like the crash happened when user try to open another content when PIP player is active resulting in the current PIP instance will be replaced with a new one. My suspect is the observation logic inside AVPlayerController could be the hint to this issue, probably something broken over there since this issue happened across our app versions on iOS 18 users only.
Unfortunately, I was unable to reproduce this issue yet but one of my colleagues reproduced it once but haven’t been able to do it again since. The reports keep raising each day up to 1.3k events in the last 30 days now.
Over release object
This one has lower reports than the first one but I decided to include it since it might have relevant information regarding the first crash since the starting stack trace is similar. The crash timing seems to be similar to the first one, where we deallocate existing AVPictureInPictureController and later replace it with a new one and also found only in iOS 18 users which also refers to [AVPlayerController _observeValueForKeyPath:oldValue:newValue:]. I also was unable to reproduce this issue so far.
Oh, and both of the issues happened on both iPhone and iPad.
We’d appreciate any advice on what we can do to avoid this in the future and probably any hint on why it could happened.
I have reported this issue with bug number: FB15620734
I also attached one sample crash report for each of the crashes here.
non ui thread access.crash
over release.crash
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Our multimedia application Boinx FotoMagico displays media files of various kinds with a Metal rendering engine. At the moment we still use .bgra8Unorm pixel format and sRGB color space and only render in SDR, which is increasingly a problem, as much of the video content is HDR nowadays (e.g. videos shot on an iPhone). For that reason we would like to switch to EDR rendering with .rgba16Float pixel format and extendedLinearDisplayP3 color space.
We have already worked out how to do this for HDR image files, but still have a technical problem when rendering HDR video files. We are using AVFoundation to get the video frames as CVPixelBuffers and convert them to MTLTexture using a CVMetalTextureCache. MTLTextures are then further processed in various compute shaders before being rendered to screen. However the pixel values in the texture are not what we expected. Video frames appear too bright/overexposed.
In WWDC21 session "Explore HDR rendering with EDR" Ken Greenebaum mentioned:
“AVFoundation does not presently decode HDR formats, such as HDR10, to EDR. Consequently, these need to be adapted for use with EDR rendering. This conversion is straightforward and involves two steps. First, converting to linear light by applying the inverse transfer function. And second, dividing by the medium's reference white.”
https://developer.apple.com/videos/play/wwdc2021/10161?time=1498
However, the session does not explain, how to get or calculate the correct value for "reference white". We could not find any relevant info on the web. This is why we need DTS assistance. We need the code that calculates the correct value for reference white for any kind of video, whether it is SDR or HDR, and regardless of codec and encoding. I assume that Ken Greenebaum is the best Apple engineer to ask in this case, because he recorded most of the EDR related WWDC sessions in recent years?
We have written a small test app that renders a short sample video (HLG encoding). The window contains two views. The upper view uses an AVPlayerLayer and renders the video natively just like QuickTime Player. The video content looks correct here. BTW, the window background is SDR white, so that bright EDR pixels can be clearly identified, e.g. the clouds just above the mountains in the upper left corner of the sample video. You may need to lower display brightness a bit if these clouds do not appear brighter than the white window background.
The bottom view uses a CAMetalLayer and low-level Metal rendering. The CVPixelBuffers we receive from AVFoundation still need to be scaled down so that SDR reference white reaches pixel value 1.0. Entering a value of 9.0 to 10.0 for reference white in the text field makes it look about right on my Studio Display. But that is just experimental for this sample video file. We need code to calculate the correct value for reference white for any kind of video file!
We have a couple of questions:
SDR videos should probably use 1.0 as reference white, as their encoded pixel values can already be used as is? Is this assumption correct?
Different video encoding of HDR video (HLG, PQ, etc) will probably lead to different values for reference white?
Is the value for reference white constant throughout a video, or can it vary over time, either scene by scene, or even frame by frame?
If it can vary, does the CVPixelBuffer of the current video frame contain all the necessary metadata to calculate the correct value?
Does the NSScreen.maximumExtendedDynamicRangeColorComponentValue also influence the reference white value?
The attached sample project is structured in a way that the only piece of code that needs to be modified is the ViewController.sdrReferenceWhiteValue() function. Please read the comments and the #warning in this function. This is where the code for calculating the reference white value should be inserted.
Here is the download link for the sample project:
https://www.dropbox.com/scl/fi/4w5gmftav5xhbixu9u6pb/HDRMetalTest.zip?rlkey=n8cm02soux3rx03vplgo6h1lm&dl=0
Topic:
Media Technologies
SubTopic:
Video
Hi All I have some problem when I using the IOS 18.4.1
I have iphone16 pro and ipad Air, both are updated to IOS 18.4.1
I tried to following sample code.
However, when I run the app around 30 seconds to 1 minutes, the application would be crashed
When I using another Ipad with IOS 17, it would not have the same problem.
https://developer.apple.com/documentation/createml/creating-an-action-classifier-model
https://developer.apple.com/documentation/createml/detecting_human_actions_in_a_live_video_feed#overview%29,
Our iOS/AppleTV video content playback app uses AVPlayer to play HLS video streams and supports both custom and system playback UIs. The Fairplay content key is retrieved using AVContentKeySession. AirPlay is supported too.
When the iPhone is connected to a TV through the lightning Apple Digital AV Adapter (A1438), the app is mirrored as expected.
Problem: when using an iPhone or iPad on iOS 18.1.1, FairPlay-protected HLS streams are not played and a CoreMediaErrorDomain -12035 error is received by the AVPlayerItem. Also, once the issue has occurred, the mirroring freezes (the TV indefinitely displays the app playback screen) although the app works fine on the iOS device.
The content key retrieval works as expected (I can see that 2 content key requests are made by the system by the way, probably one for the local playback and one for the adapter, as when AirPlaying) and the error is thrown after providing the AVContentKeyResponse.
Unfortunately, and as far as I know, there is not documentation on CoreMediaErrorDomain errors so I don't know what -12035 means.
The issue does not occur:
on an iPhone on iOS 17.7 (even with FairPlay-protected HLS streams)
when playing DRM-free video content (whatever the iOS version)
when using the USB-C AV Adapter (whatever the iOS version)
Also worth noting: the issue does not occur with other video playback apps such as Apple TV or Netflix although I don't have any details on the kind of streams these apps play and the way the FairPlay content key is retrieved (if any) so I don't know if it is relevant.
(This only started happening as of Xcode 26.)
I know macOS and watchOS don't support this property, but all other platforms do (did?) up until I upgraded Xcode. Now when I compile I get this:
Value of type 'AVPlayerItem' has no member 'externalMetadata'
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!
When setting the now playing info for playing media in MPNowPlayingInfoCenter we can set artwork. But it seems the Apple API for creating the artwork is crashing on iOS 18 (FB15145734).
On iOS 17 this gave the warning that the completion handler was not run on the main thread.
I've tried to seek help here: https://stackoverflow.com/questions/78989543/swift-data-race-with-appkit-mpmediaitemartwork-function/78990231?noredirect=1#comment139277425_78990231
but it seems that it's not possible to override the completion handler and therefor it's up to Apple to fix this issue.
.task {
await MainActor.run {
let nowPlayingInfoCenter = MPNowPlayingInfoCenter.default()
var nowPlayingInfo = [String: Any]()
let image = NSImage(named: "image")!
// warning: data race detected: @MainActor function at MPMediaItemArtwork/ContentView.swift:22 was not called on the main thread
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size, requestHandler: { _ in
// Not on main thread here!
return image
})
nowPlayingInfoCenter.nowPlayingInfo = nowPlayingInfo
}
}
I'm wondering if there is an alternative method to set the now playing artwork?
I noticed that AVSampleBufferDisplayLayerContentLayer is not released when the AVSampleBufferDisplayLayer is removed and released.
It is possible to reproduce the issue with the simple code:
import AVFoundation
import UIKit
class ViewController: UIViewController {
var displayBufferLayer: AVSampleBufferDisplayLayer?
override func viewDidLoad() {
super.viewDidLoad()
let displayBufferLayer = AVSampleBufferDisplayLayer()
displayBufferLayer.videoGravity = .resizeAspectFill
displayBufferLayer.frame = view.bounds
view.layer.insertSublayer(displayBufferLayer, at: 0)
self.displayBufferLayer = displayBufferLayer
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
self.displayBufferLayer?.flush()
self.displayBufferLayer?.removeFromSuperlayer()
self.displayBufferLayer = nil
}
}
}
In my real project I have mutliple AVSampleBufferDisplayLayer created and removed in different view controllers, this is problematic because the amount of leaked AVSampleBufferDisplayLayerContentLayer keeps increasing.
I wonder that maybe I should use a pool of AVSampleBufferDisplayLayer and reuse them, however I'm slightly afraid that this can also lead to strange bugs.
Edit: It doesn't cause leaks on iOS 18 device but leaks on iPad Pro, iOS 17.5.1
Our streaming app uses FairPlay-protected video streams, which previously worked fine when using AVAssetResourceLoaderDelegate to provide CKCs.
Recently, we migrated to AVContentKeySession, and while everything works as expected during regular playback, we encountered an issue with AirPlay.
Our CKC has a 120-second expiry, so we renew it by calling renewExpiringResponseData..
This trigger the didProvideRenewingContentKeyRequest delegate and we respond with updated CKC.
However, when streaming via AirPlay, both video and audio freeze exactly after 120 seconds.
To validate the issue, I tested with AVAssetResourceLoaderDelegate and found that I can reproduce the same freeze if I do not renew the key. This suggests that AirPlay is not accepting the renewed CKC when using AVContentKeySession.
Additional Details:
This issue occurs across different iOS versions and various AirPlay devices.
The same content plays without issues when played directly on the device.
The renewal process is successful, and segments continue to load, but playback remains frozen.
Tried renewing the CKC bit early (100s).
I also tried setting player.usesExternalPlaybackWhileExternalScreenIsActive = true, but the issue persists.
We don't use persistentKey.
Is there anything else that needs to be considered for proper key renewal when AirPlaying?
Any help on how to fix this or confirmation if this is a known issue would be greatly appreciated.
Does anyone have a template of an Apple Projected Media Profile Format Description or a File of a Stereo wideFOV video?
Use case I have 2 compatible cameras that I stereo sync and I want to move the projection information from the compatible video to the Spatial video that combines them.
Every version I can come up with crashes the AVP and when viewing as Spatial in Tahoe I just get a black screen.
When i use AVPlayer to obtain the video frame CVPixelBufferRef of an HDR video, and use AVSampleBufferDisplayLayer to display it on the screen, after a period of time, the HDR video content and screen gradually darken, losing the HDR effect.
Steps to reproduce:
Create an AVPlayer to loop an HDR video, specify the video frame format as kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange
Create a timer to get the video frame CVPixelBufferRef at 30 frames per second
Use AVSampleBufferDisplayLayer to display CVPixelBufferRef on the screen
Don't operate the phone, wait for a period of time (such as 40 minutes), the HDR effect disappears and the screen darkens
Note:
You need to use an iPhone device, iOS 18.5 and below operating system
You need to ensure that the HDR video is played in a loop, that is, to ensure that the screen continues to display HDR content, wait for a period of time, depending on different devices, you need to wait for 20-40 minutes.
In the iPhone Photos app,the same problem will occur after playing HDR video in a loop for a long time
Expected Results:
When rendering HDR content for a long time, it is guaranteed that there is always an HDR effect, and the HDR content and screen will not be darkened.
Current Results:
After about 20-40 minutes, the HDR effect disappears and the screen darkens.
Hi everyone,
I am currently on MacOS Tahoe (26.1), and for some weird reason my mac is not connecting via HDMI. To be accurate: it is connecting and the LG TV shows up in the Displays settings, but no image shows up in it, I have no idea why. This used to work as I've tried this cable before with the same exact tv. The cable is a basic Amazon Basics HDMI one.
Allow me just to advanced this question a little: usually terminal commands are more advanced recommendations, whereas basic questions like "have you connected it right" are just a waste of time
Topic:
Media Technologies
SubTopic:
Video
Hi all,
I'm trying to diagnose and resolve an issue with stuttering video playback using the standard AVPlayer. The video in question is a 4K, 39-second file in *.mov format, being played on an iOS device. It's served via a local HTTP server that proxies requests to a backend to fetch and process the content. The project uses end-to-end encrypted storage, which necessitates the proxy for handling data processing. While playback in offline scenarios is smooth, we are encountering issues with smooth playback during streaming. The same video streams smoothly on other platforms using the same connection, so network limitations are not a factor.
On iOS, playback is consistently choppy, with pauses every 1-3 seconds. The video does not appear to buffer adequately for smooth playback.
One particularly curious aspect is the seemingly random pattern of Content-Range requests made by the AVPlayer when streaming the video. Below is an example of the range requests:
Topic:
Media Technologies
SubTopic:
Video
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)
}
}
I'm working on an application that uses the iPhone camera for scientific purposes - and, as a result would like to receive video in as unprocessed format as possible.
In particular, I'm interested in getting pixel buffers that contain pretty much the bayer data as the sensor sees it - with the minimum processing of color possible.
Currently we configure the AVCaptureDevice to fix the focus and exposure, use a low ISO with no gain and set the white balance gains to 1. AVCaptureVideoDataOutput is using 32BGRA.
What I'd like to do is remove any additional color and brightness processing such that the data is effectively processed with a linear transfer function (i.e. gamma function is 1).
I thought that this might be down to using the AVCaptureDevice activeColorSpace - we currently use P3_D65 for this. But there only seems to be a few choices (e.g. sRGB, HLG_BT2020) all of which I think affect the gamma.
So:
is it possible to control or specify the gamma / transfer function when using CaptureVideoDelegate?
if not, does one of the color space settings have a defined gamma function that I can effectively reverse it from the pixel data without losing too much information?
or is there a better way to capture video-ish speed images (15-30fps) from the camera sensor that skips processing like this?
Many thanks for any suggestions.
I am working on a project for macOS where I am taking an AVCaptureSession's CVPixelBuffer and I need to convert it into a MTLTexture for rendering. On macOS the pixel format is 2vuy, there does not seem to be a clear format conversion while converting to a metal texture. I have been able to convert it to a texture but the color space seems to be off as it is rendering distorted colors with a double image.
I believe 2vuy is a single pane color space and I have tried to account for that, but I am unaware of what is off.
I have attached The CVPixelBuffer and The distorted MTLTexture along with a laundry list of errors.
On iOS my conversions are fine, it is only the macOS 2vuy pixel format that seems to have issues.
My code for the conversion is also attached.
If there are any suggestions or guidance on how to properly convert a 2vuy CVPixelBuffer to a MTLTexture I would greatly appreciate it.
Many Thanks
Conversion_Logs.txt
ConversionCode.swift
I'm using an AVCaptureSession to send video and audio samples to an AVAssetWriter. When I play back the resultant video, sometimes there is a significant lag between the audio compared with the video, so they're just not in sync. But sometimes they are, with the same code.
If I look at the very first presentation time stamps of the buffers being sent to the delegate, via
func captureOutput(_: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection)
I see something like this:
Adding audio samples for pts time 227711.0855328798,
Adding video samples for pts time 227710.778785374
That is, the clock for audio vs video is behind: the first audio sample I receive is at 11.08 something, while the video video sample is earlier in time, at 10.778 something. The times are the presentation time stamps of the buffer, and the outputPresentationTimeStamp is the exact same number.
It feels like "video" vs the "audio" clock are just mismatched.
This doesn't always happen: sometimes they're synced. Sometimes they're not.
Any ideas? The device I'm recording is a webcam, on iPadOS, connected via the usb-c port.
I'm capturing video stream from GoPro camera (I demux UDP MPEG-TS packets) and create CMSampleBuffers from them, this works fine when I display them using CMSampleBufferLayer.
However when I dump them to disk using AVAssetWriter and then playback it with AVPlayer, AVPlayer has problems with scrubbing, it also cannot render previous frames, it needs to go back to key frames. Also thumbnails generated with AVAssetImageGenerator are mostly distorted and green, even though I set the requestedTimeToleranceAfter longer than the key frames frequency.
When I re-encode saved video once again with AVAssetExportSession and play it back then I can scrub the video just fine.
Is it because re-transcoding adds additional metadata to enable generating frames when rewinding the video and scrubbing?
If so is there a way to achieve it with AVAssetWriter without much time penalty? I need the dump/save operation to be very fast.
I also considered the following: Instead of de-muxing video and creating CMSampleBuffers, maybe I could directly dump the stream to disk and somehow add moov atoms with timing information. Would this approach work? If so where I can find information how to do it?
Thank you!
I'm working on an app where a user needs to select a video from their Photos library, and I need to get the original, unmodified HEVC (H.265) data stream to preserve its encoding.
The Problem
I have confirmed that my source videos are HEVC. I can record a new video with my iPhone 15 Pro Max camera set to "High Efficiency," export the "Unmodified Original" from Photos on my Mac, and verify that the codec is MPEG-H Part2/HEVC (H.265).
However, when I select that exact same video in my app using PHPickerViewController, the itemProvider does not list public.hevc as an available type identifier. This forces me to fall back to a generic movie type, which results in the system providing me with a transcoded H.264 version of the video.
Here is the debug output from my app after selecting a known HEVC video:
⚠️ 'public.hevc' not found. Falling back to generic movie type (likely H.264).
What I've Tried
My code explicitly checks for the public.hevc identifier in the registeredTypeIdentifiers array. Since it's not found, my HEVC-specific logic is never triggered.
Here is a minimal version of my PHPickerViewControllerDelegate implementation:
import UniformTypeIdentifiers
// ... inside the Coordinator class ...
func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
picker.dismiss(animated: true)
guard let result = results.first else { return }
let itemProvider = result.itemProvider
let hevcIdentifier = "public.hevc"
let identifiers = itemProvider.registeredTypeIdentifiers
print("Available formats from itemProvider: \(identifiers)")
if identifiers.contains(hevcIdentifier) {
print("✅ HEVC format found, requesting raw data...")
itemProvider.loadDataRepresentation(forTypeIdentifier: hevcIdentifier) { (data, error) in
// ... process H.265 data ...
}
} else {
print("⚠️ 'public.hevc' not found. Falling back to generic movie type (likely H.264).")
itemProvider.loadFileRepresentation(forTypeIdentifier: UTType.movie.identifier) { url, error in
// ... process H.264 fallback ...
}
}
}
My Environment
Device: iPhone 15 Pro Max
iOS Version: iOS 18.5
Xcode Version: 16.2
My Questions
Are there specific conditions (e.g., the video being HDR/Dolby Vision, Cinematic, or stored in iCloud) under which PHPickerViewController's itemProvider would intentionally not offer the public.hevc type identifier, even for an HEVC video?
What is the definitive, recommended API sequence to guarantee that I receive the original, unmodified data stream for a video asset, ensuring that no transcoding to H.264 occurs during the process?
Any insight into why public.hevc might be missing from the registeredTypeIdentifiers for a known HEVC asset would be greatly appreciated. Thank you.
Because I want to control the grid size and number of HEIC images myself, I decided to perform HEVC encoding manually and then generate the HEIC image. Previously, I used VTCompressionSession to accomplish this task, and the results were satisfactory. It worked perfectly on iOS 16 through iOS 18 — in other words, it was able to generate correct HEVC encoding, and its CMFormatDescription should also have been correct, since I relied on it to generate the decoderConfig; otherwise, the final image would have decoding issues.
However, it can no longer generate a valid HEIC image on a physical device running iOS 26. Interestingly, it still works fine on the iOS 26 simulator — it only fails on real hardware. The abnormal result is that the image becomes completely black, although the image dimensions are still correct.
After my troubleshooting, I suspect that the encoding behavior of VTCompressionSession has been modified on iOS 26, which causes the final hvc1 encoding I pass in to be incorrect.
I created a VTCompressionSession using the following configuration.
var newSession: VTCompressionSession!
var status = VTCompressionSessionCreate(
allocator: kCFAllocatorDefault,
width: Int32(frameSize.width),
height: Int32(frameSize.height),
codecType: kCMVideoCodecType_HEVC,
encoderSpecification: nil,
imageBufferAttributes: nil,
compressedDataAllocator: nil,
outputCallback: nil,
refcon: nil,
compressionSessionOut: &newSession
)
try check(status, VideoToolboxErrorDomain)
let properties: [CFString: Any] = [
kVTCompressionPropertyKey_AllowFrameReordering: false,
kVTCompressionPropertyKey_AllowTemporalCompression: false,
kVTCompressionPropertyKey_RealTime: false,
kVTCompressionPropertyKey_MaximizePowerEfficiency: false,
kVTCompressionPropertyKey_ProfileLevel: profileLevel,
kVTCompressionPropertyKey_Quality: quality.rawValue,
]
status = VTSessionSetProperties(newSession, propertyDictionary: properties as CFDictionary)
try check(status, VideoToolboxErrorDomain) {
VTCompressionSessionInvalidate(newSession)
}
Then use the following code to encode each Grid of the image.
let status = VTCompressionSessionEncodeFrame(
session,
imageBuffer: buffer,
presentationTimeStamp: presentationTimeStamp,
duration: frameDuration,
frameProperties: nil,
infoFlagsOut: nil) { [weak self] status, _, sampleBuffer in
try check(status, VideoToolboxErrorDomain)
if let sampleBuffer {
let encodedImage = try self.encodedImage(from: sampleBuffer)
// handle encodedImage
}
}
try check(status, VideoToolboxErrorDomain)
If I try to display this abnormal image in the App, my console outputs the following error, so it can be inferred that the issue probably occurred during decoding.
createImageBlock:3029: *** ERROR: CGImageBlockCreate {0, 0, 2316, 6176} - data is NULL
callDecodeImage:2411: *** ERROR: decodeImageImp failed - NULL _blockArray
createImageBlock:3029: *** ERROR: CGImageBlockCreate {0, 0, 2316, 6176} - data is NULL
callDecodeImage:2411: *** ERROR: decodeImageImp failed - NULL _blockArray
createImageBlock:3029: *** ERROR: CGImageBlockCreate {0, 0, 2316, 6176} - data is NULL
callDecodeImage:2411: *** ERROR: decodeImageImp failed - NULL _blockArray
It needs to be emphasized again that this code used to work fine in the past, and the issue only occurs on an iOS 26 physical device. I noticed that iOS 26 has introduced many new properties, but I’m not sure whether some of these new properties must be set in the new system, and there’s no information about this in the official documentation.