I'm currently using ReplayKit for background screen recording, but I can't determine whether the screen is in landscape mode from the CMSampleBuffer. All other APIs for detecting screen orientation are foreground-based. What should I do?
Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.
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When I play an m3u8 video using AVPlayer, it can play smoothly at 2x speed. However, when I set it to 3x speed, the playback is not smooth and there is no sound.
Topic:
Media Technologies
SubTopic:
Video
How can I setup correctly AVSampleBufferDisplayLayer for video display when I have input picture format kCVPixelFormatType_32BGRA?
Currently video i visible in simulator, but not iPhone, miss I something?
Render code:
var pixelBuffer: CVPixelBuffer?
let attrs: [String: Any] = [
kCVPixelBufferPixelFormatTypeKey as String: kCVPixelFormatType_32BGRA,
kCVPixelBufferWidthKey as String: width,
kCVPixelBufferHeightKey as String: height,
kCVPixelBufferBytesPerRowAlignmentKey as String: width * 4,
kCVPixelBufferIOSurfacePropertiesKey as String: [:]
]
let status = CVPixelBufferCreateWithBytes(
nil,
width,
height,
kCVPixelFormatType_32BGRA,
img,
width * 4,
nil,
nil,
attrs as CFDictionary,
&pixelBuffer
)
guard status == kCVReturnSuccess, let pb = pixelBuffer else { return }
var formatDesc: CMVideoFormatDescription?
CMVideoFormatDescriptionCreateForImageBuffer(
allocator: nil,
imageBuffer: pb,
formatDescriptionOut: &formatDesc
)
guard let format = formatDesc else { return }
var timingInfo = CMSampleTimingInfo(
duration: .invalid,
presentationTimeStamp: currentTime,
decodeTimeStamp: .invalid
)
var sampleBuffer: CMSampleBuffer?
CMSampleBufferCreateForImageBuffer(
allocator: kCFAllocatorDefault,
imageBuffer: pb,
dataReady: true,
makeDataReadyCallback: nil,
refcon: nil,
formatDescription: format,
sampleTiming: &timingInfo,
sampleBufferOut: &sampleBuffer
)
if let sb = sampleBuffer {
if CMSampleBufferGetPresentationTimeStamp(sb) == .invalid {
print("Invalid video timestamp")
}
if (displayLayer.status == .failed) {
displayLayer.flush()
}
DispatchQueue.main.async { [weak self] in
guard let self = self else {
print("Lost reference to self drawing")
return
}
displayLayer.enqueue(sb)
}
frameIndex += 1
}
Hello! I have been following the UsingAVFoundationToPlayAndPersistHTTPLiveStreams sample code in order to test persisting streams to disk. In addition to support for m3u8, I have noticed in testing that this also seems to work for MP3 Audio, simply by changing the plist entries to point to remote URLs with audio/mpeg content. Is this expected, or are there caveats that I should be aware of?
Thanks you!
When trying to edit some Live Photos, calling PHLivePhotoEditingContext.saveLivePhoto results in the following error:
Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSLocalizedFailureReason=An unknown error occurred (-12815), NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x300d05380 {Error Domain=NSOSStatusErrorDomain Code=-12815 "(null)"}}
I was able to replicate it on my device by taking a new Live Photo. Not sure what's wrong with that one specifically, not all Live Photos replicate the issue.
I've submitted FB15880825 with a sysdiagnose and a Photos Diagnostics as well. Any ideas what's going on here? It's impacting multiple customers. Thanks!
Topic:
Media Technologies
SubTopic:
Photos & Camera
Tags:
Media
Photos and Imaging
PhotoKit
AVFoundation
The app registers a periodic time observer to the AVPlayer when the playback starts and it works fine. When switching to AirPlay during playback, the periodic time observation continues working as expected.
However, when switching back to local playback, the periodic time observer does not fire anymore until a seek is performed. The app removes the periodic time observer only when the playback stops.
I can see that when switching back to local playback, the timeControlStatus successively changes
to .waitingToPlayAtSpecifiedRate (reason: .evaluatingBufferingRate)
then to .waitingToPlayAtSpecifiedRate (reason: .toMinimizeStalls)
and finally to .playing
But the time observation does not work anymore.
Also, the issue is systematic with Live and VOD streams providing a program date (with HLS property #EXT-X-PROGRAM-DATE-TIME), with or without any DRM, and is never reproduced with other VOD streams.
I am developing a VOD playback app, but when I stream video to an external monitor connected via HDMI with Lightning on iOS 18 or later, the screen goes dark and I cannot confirm playback.
The app I am developing does not detect the HDMI and display the Player separately, but simply mirrors the video.
We have confirmed that the same phenomenon occurs with other services, but we were able to confirm playback with some services such as Apple TV.
Please let us know if there are any other necessary settings such as video certificates required for video playback.
We would also like to know if the problem occurs with iOS 18 or later.
Topic:
Media Technologies
SubTopic:
Audio
We have the necessary background recording entitlements, and for many users... do not run into any issues.
However, there is a subset of users that routinely get recordings ending.. we have narrowed this down and believe it to be the work of the watch dog.
First we removed the entire view hierarchy when app is backgrounded. There is just 'Text("Recording")'
This got the CPU usage in profiler down to 0%. We saw massive improvements to recording success rate.
We walked away assuming that was enough. However we are still seeing the same sort of crashes. All in the background. We're using Observation to drive audio state changes to a Live Activity.
Are those Observations causing the problem? Why doesn't apple provide a better API to background audio? The internet is full of weird issues
https://stackoverflow.com/questions/76010213/why-is-my-react-native-app-sometimes-terminated-in-the-background-while-tracking
https://stackoverflow.com/questions/71656047/why-is-my-react-native-app-terminating-in-the-background-while-recording-ios-r
https://github.com/expo/expo/issues/16807
This is such a terrible user experience. And we have very little visibility into what is happening and why.
No where in apple documentation states that in order for background recording to work, the app can only be 'Text("Recording")'
It does not outline a CPU or memory threshold. It just kills us.
I have an app that displays artwork via MPMediaItem.artwork, requesting an image with a specific size. How do I get a media item's MPMediaItemAnimatedArtwork, and how to get the preview image and video to display to the user?
I’m currently working on a project where I capture both depth frames and RGB frames using AVCaptureDataOutputSynchronizer. Depth frames are stored as raw binary data and RGB frames are saved with AVAssetWriter.
The issue I’m facing is that AVAssetWriter enforces a fixed framerate, meaning it adds or discards frames to maintain that rate (as I understand it). This causes a desynchronization between the depth and RGB frames, which is a problem because I need each depth frame to be exactly matched with the corresponding RGB frame as they were captured.
How can I ensure that the RGB frames are saved without AVAssetWriter modifying the frame count?
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.)
Short summary
When setting exposureMode to .locked or .custom the brightness of a video stream still changes depending on the composition and contrast of the visible scene. These changes seem to come from contrast enhancements or dynamic range optimizations and totally break any analysis of the image that requires to assess absolute luminance. While exposure lock seems to indeed lock the physical exposure parameters of the camera (shutter speed and ISO), I cannot find any way to control these "soft" modifiers.
Details
Background
I am the developer of the app "phyphox", an educational app that makes the phone's sensors accessible to students as measurement tools in science experiments. Currently I am working on implementing photometric measurements through the camera and one very important aspect of it is luminance measurements.
This is particularly relevant since the light sensor of the phone has no publicly accessible API and the camera could to some extend make experiments available to Apple users that are otherwise only possible on Android devices.
Implementation
The app uses AVFoundation and explicitly picks individual cameras since camera groups do not support custom exposure settings. This means that it handles camera switching during zoom by itself and even implements its own auto exposure routines to optimize for the use in experiments. Therefore it always stays in custom exposure mode. The app uses YUV420 color space and the individual frames are analyzed in Metal using compute shaders.
However, the effects discussed here still occur if I remove all code to control the camera and replace it with a simple sequence of setting the exposure mode to custom, setting custom exposure values, setting a fixed white balance and then setting the exposure mode to locked as suggested on stackoverflow. This neither helps on an iPhone 14 Pro nor on an iPhone 8 despite a report on the developer forums that it would resolve the issue for older devices.
The app is open source, so the code can be seen in our current development branch (without the changes for the tests here, though) on github.
The videos below use the implementation with the suggestion from stackoverflow, but they can be reproduced in the same way with "professional" camera apps that promise manual control over the camera (like the Blackmagic cam to quote a reputable company) as well as the stock camera app after pressing and holding on the preview to enable AE/AF lock.
Demonstration
These examples were captured on an iPhone 14 Pro. The central part of the image (highlighted by the app using metal shaders after capture) should not change with fixed exposure settings, but significant changes are noticable if there are changes at the edge of the frame when I move a black piece of cardboard in from above:
https://share.icloud.com/photos/0b1f_3IB6yAQG-qSH27pm6oDQ
The graph above the camera preview is the average luminance (gamma corrected and weighted based on sRGB) across the highlighted central area and as mentioned before it should not change because of something happening at the side of the frame (worst case it should get a bit darker because of the cardboard's shadow).
In my opinion, the iPhone changes its mind on the ideal contrast as soon as it has a different exposure histogram because of the dark image part from the cardboard, but that's just me guessing.
For completeness here is the same effect in the stock camera app with AE/AF lock enabled:
https://share.icloud.com/photos/0cd7QM8ucBZKwPwE9mybnEowg
Here you can also see that the iPhone "ramps" the changes. The brightness of the gray area does not change immediately but transitions smoothly, so this is clearly deliberate postprocessing.
So...
Any suggestion on how to prevent this behavior would be highly appreciated.
Hi! I am making an app for Apple Vision pro (VisionOS 2.5) that is scanning the surroundings and recognises all the texts around you. I tried to use the AVCaptureSession library, but when I run the app from xcode on the real AVP device, the camera is not accessible. I enabled the camera access in my Info.plist: NSCameraUsageDescription Used for live text recognition and I checked camera settings in the AVP, there are no restrictions. However I have always a black square with a crossed camera icon displayed instead of the image from the camera.
I tried a couple of different apps from Github using the AVCaptureSession and they all display the black square instead of the picture.
What can be wrong with the camera?
Topic:
Media Technologies
SubTopic:
Photos & Camera
Hi Team,
We are using AVFoundation to read metadata from a stream and have noticed some delay between when the stream provides metadata and when the app receives it. Could someone from the team advise on ways to reduce this?
Thanks
I'm reaching out regarding a recurring issue I'm experiencing with MusicKit developer tokens.
I'm using a valid .p8 private key to sign JWTs for Apple MusicKit integration. Each token I generate includes the appropriate claims (iss, iat, exp) and is signed with the ES256 algorithm, with an expiration date set approximately 6 months ahead.
Everything works as expected immediately after generating the token. However, after a few days, the same JWT (still well within its expiration period) suddenly begins returning invalid/unauthorized responses when used in Postman and other API clients.
Importantly:
I did not delete or revoke the .p8 key during this time.
I verified the JWT contains valid claims and a proper structure.
The issue consistently resolves only when I create a new .p8 file and regenerate a fresh JWT with it—after which the cycle repeats.
This issue occurs even when the environment and app identifiers remain unchanged.
I would greatly appreciate it if you could help me understand:
Why these tokens become invalid after a few days, despite having a long exp value and an unchanged key.
Whether there's any automatic revocation or timeout policy on .p8 keys that could explain this behavior.
If there's a better way to maintain long-lived developer tokens without requiring new .p8 key generation every few days.
Thank you for your help and clarification on this issue.
Best regards,
Liad Altif
I have an app under development - demo here - https://youtu.be/VbAfUk_eYl0?si=s6EDBx-4G6P_QbZO - which is sort of an audio player for airdropped files - something useful to musicians who dump work in progress to their phone, make notes, revise and update.
I've been testing my handling of audio session interruption notifications, but seems to be a lot of inconsistency in how, when and why iOS delivers them, and I'm wondering if there is some rhyme or reason to it that I'm just not detecting.
For example, I am playing a song in my app. Switch to Apple Music and start playing a song there. My app gets an interruption began notification - this is consistent.
Switch back to my app, and about half the time, I will get an interruption ended notification (coupled often with a blast of the tail of whatever audio buffer was partially played when the interruption started, even though the engine was stopped - and followed by call to my AVAudioPlayerNodeCompletionCallback - is there some way to avoid this?). Half the time I don't get an interruption ended notification; my app can (as expected) end the interruption by activating the AVAudioSession and playing something.
I have not been able to determine any pattern to this behavior, other than that if my app started playing using AVAudioPlayerNode.scheduleSegment rather than scheduleFile I think the notification will be consistently delivered on app activation rather than when I activate the session programmatically.
I would like my app to behave deterministically, and would appreciate any help in deciphering what causes the inconsistent behavior in notifications from iOS.
When I create a SFSpeechRecognizer object, I find SFLocalSpeechRecognitionClient remains in memory and never gets released.
You can create a demo with a single UIButton whose touch action is
SFSpeechRecognizer(locale: Locale(identifier: "zh_CN"))
We noticed the behaviour of expiration of FairPlay license changed from iOS 16.x to some version iOS 17 and the latest iOS 18.3.2 and Safari.
On iOS 16.x, the video playback will stop when the license expires, but on iOS 17.x + the video continues but no audio and no error fired.
On latest Safari the video and audio all continues.
Any changes for the latest FairPlay and how we adapt this from the license server?
Thanks
In iOS 18, CarPlay shows an error: “There was a problem loading this content” after playback starts. Audio works fine, but the Now Playing screen doesn’t load. I’m using MPPlayableContentManager. This worked fine in iOS 17. Anyone else seeing this error in iOS 18?
Hi, I’m working on a photo backup app.
I track the PHAsset localIdentifier to determine which photos have been backed up and which haven’t.
Recently, I’ve noticed that two users seem to have experienced the localIdentifier changes after transferring data to a new iPhone using Quick Start.
Additionally, others on StackOverflow have mentioned that the localIdentifier sometimes changes after updating the iOS version.
https://stackoverflow.com/questions/40094728/phobject-localidentifier-reliability
I’d like to confirm the reliability of the localIdentifier after an iOS version upgrade or device transfer.
Can I continue using these locally stored localIdentifiers?
Or is there another recommended approach, such as using PHCloudIdentifier?