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

I’m using the shared instance of AVAudioSession. After activating it with .setActive(true), I observe the outputVolume, and it correctly reports the device’s volume. However, after deactivating the session using .setActive(false), changing the volume, and then reactivating it again, the outputVolume returns the previous volume (before deactivation), not the current device volume. The correct volume is only reported after the user manually changes it again using physical buttons or Control Center, which triggers the observer. What I need is a way to retrieve the actual current device volume immediately after reactivating the audio session, even on the second and subsequent activations. Disabling and re-enabling the audio session is essential to how my application functions. I’ve tested this behavior with my colleagues, and the issue is consistently reproducible on iOS 18.0.1, iOS 18.1, iOS 18.3, iOS 18.5 and iOS 18.6.2. On devices running iOS 17.6.1 and iOS 16.0.3, outputVolume correctly reflects the current volume immediately after calling .setActive(true) multiple times.

Hello. My team and I think we have an issue where our app is asked to gracefully shutdown with a following SIGTERM. As we’ve learned, this is normally not an issue. However, it seems to also be happening while our app (an audio streamer) is actively playing in the background. From our perspective, starting playback is indicating strong user intent. We understand that there can be extreme circumstances where the background audio needs to be killed, but should it be considered part of normal operation? We hope that’s not the case. All we see in the logs is the graceful shutdown request. We can say with high certainty that it’s happening though, as we know that playback is running within 0.5 seconds of the crash, without any other tracked user interaction. Can you verify if this is intended behavior, and if there’s something we can do about it from our end. From our logs it doesn’t look to be related to either memory usage within the app, or the system as a whole. Best, John

I'm creating Live Photos programmatically in my app using the Photos and AVFoundation frameworks. While the Live Photos work perfectly in the Photos app (long press shows motion), users cannot set them as motion wallpapers. The system shows "Motion not available" message. Here's my approach for creating Live Photos: // 1. Create video with required metadata let writer = try AVAssetWriter(outputURL: videoURL, fileType: .mov) let contentIdentifier = AVMutableMetadataItem() contentIdentifier.identifier = .quickTimeMetadataContentIdentifier contentIdentifier.value = assetIdentifier as NSString writer.metadata = [contentIdentifier] // Video settings: 882x1920, H.264, 30fps, 2 seconds // Added still-image-time metadata at middle frame // 2. Create HEIC image with asset identifier var makerAppleDict: [String: Any] = [:] makerAppleDict["17"] = assetIdentifier // Required key for Live Photo metadata[kCGImagePropertyMakerAppleDictionary as String] = makerAppleDict // 3. Generate Live Photo PHLivePhoto.request( withResourceFileURLs: [photoURL, videoURL], placeholderImage: nil, targetSize: .zero, contentMode: .aspectFit ) { livePhoto, info in // Success - Live Photo created } // 4. Save to Photos library PHAssetCreationRequest.forAsset().addResource(with: .photo, fileURL: photoURL, options: nil) PHAssetCreationRequest.forAsset().addResource(with: .pairedVideo, fileURL: videoURL, options: nil) What I've Tried Matching exact video specifications from Camera app (882x1920, H.264, 30fps) Adding all documented metadata (content identifier, still-image-time) Testing various video durations (1.5s, 2s, 3s) Different image formats (HEIC, JPEG) Comparing with exiftool against working Live Photos Expected Behavior Live Photos created programmatically should be eligible for motion wallpapers, just like those from the Camera app. Actual Behavior System shows "Motion not available" and only allows setting as static wallpaper. Any insights or workarounds would be greatly appreciated. This is affecting our users who want to use their created content as wallpapers. Questions Are there additional undocumented requirements for Live Photos to be wallpaper-eligible? Is this a deliberate restriction for third-party apps, or a bug? Has anyone successfully created Live Photos that work as motion wallpapers? Environment iOS 17.0 - 18.1 Xcode 16.0 Tested on iPhone 16 Pro

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

My MusicKit developer token returns 401 (empty body) on every Apple Music API catalog endpoint. I've tried two different keys — both fail identically. Setup: Team ID: K79RSBVM9G Key ID: URNQV5UDGB (MusicKit enabled, associated with Media ID media.audio.explore.musickit) Apple Developer Program License Agreement accepted April 14, 2026 Token format (matches docs exactly): Header: {"alg":"ES256","kid":"URNQV5UDGB"} Payload: {"iss":"K79RSBVM9G","iat":,"exp":<now+15777000>} What works: /v1/storefronts/us returns 200 What fails: Every catalog endpoint returns 401 with empty body: /v1/catalog/us/search?types=artists&term=test /v1/catalog/us/artists/5920832 /v1/catalog/us/genres /v1/test The token self-verifies (signature is valid). I've tried with and without typ:"JWT", with the origin claim, and with a manually signed JWT bypassing the jsonwebtoken library. Same 401 every time. What am I missing?

On macOS 26.2 (Tahoe), the Preview app fails to render many USDZ models correctly. The issue appears inconsistent: • Some USDZ files open normally in Preview • Some USDZ files open but the viewport turns completely black (no geometry, no material, no lighting) • All the same files open correctly when opened using “Open With → Xcode” This was not the behavior on macOS 15.7.2, where the exact same USDZ files rendered consistently in Preview without failures.

Hello, We are trying to use the new Background Upload Extension to improve uploads of assets (Photos, Live Photos, Videos) in the background in our application. 1 - We implemented the code to upload still images. We would like to do the same for Live Photos but we are not sure how to proceed since a Live Photo is composed of 2 resources that we would like to upload in the same job so that we keep the association between the 2 resources. Steps: A Live Photo is captured on the device. Our application is notified for new content in the Photo Library and the asset is queued for upload by our application. The system calls the background upload extension and the Live Photo is prepared for upload but we can schedule a job only for one resource (still photo or paired video) so we can not upload both resources in a single job. 2 - Is there a way to synchronise the application and the extension so that the application would not process the same data or execute the same requests than the extension. For example: our application is working with tokens and we would like to prevent those tokens to be consumed by the application and the extension at the same time. 3 - is there a command in xcode or terminal to start or stop the extension, something similar to what exists for processing tasks (https://developer.apple.com/documentation/backgroundtasks/starting-and-terminating-tasks-during-development).

Hello, My company has an in-store app with FPS SDK 4.x (1024) keys. We've handed those keys over to a trusted third-party and we do not have them. We've been in-store for several years. The person that created the keys in our organization mistakenly stored them encrypted to our third-party's PGP keys, so we cannot decrypt them, and the third party also has no mechanism to provide us with the keys even though it is in their runtime environment. They only have secure mechanisms for us to upload keys onto their servers. We are trying to migrate to a different third-party DRM provider, and would like to obtain new keys. Unfortunately, the developer portal won't let me create new keys, saying that we have exceeded the number of keys allowed, which I assume is one. Additionally, the new DRM provider can only support SDK 4.x keys, and it appears that we can only request SDK 5.x keys on the Apple Developer portal, as the SDK 4.0 option is grayed out. Regardless, it seems that we are not able to request any keys. We've submitted a request to the support e-mail address and received an automated e-mail that the response should take a few days, but may take longer on occasion. It's now been a month. The e-mail says that the reply address is not monitored. Is there any way we can accelerate this? Thank you, Carlos

getting an interesting error attempting to compile my app in Xcode 26 beta. error: Unable to find module dependency: '_MediaPlayer_AppIntents' (in target 'icatcher' from project 'icatcher') note: A dependency of main module 'MainModuleCrossImportOverlays' (in target 'icatcher' from project 'icatcher') Unable to find module dependency: '_MediaPlayer_AppIntents' Not sure what to try and pull to fix this issue

With older iOS versions, when user taps Mute/Volume button on AVPLayerViewController to unmute, the system restores the sound volume of device to the level when user muted before. On iOS 26, when user taps unmute button on screen, the volume starts from 0 (not restore). (but it still restores if user unmutes by pressing physical volume buttons). As I understand, the Volume bar/button on AVPlayerViewController is MPVolumeView, and I can not control it. So this is a feature of the system. But I got complaints that this is a bug. I did not find documents that describe this change of Mute button behavior. I need some bases to explain this situation. Thank you.

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'.

I’m an amateur developer working on a free utility for composers/producers, for which the macOS release needs to create and name RTP-MIDI sessions in Audio MIDI Setup from the command line (so I can ship a small C helper instead of telling users to click through the UI). Here’s what I’ve tried so far, without luck: • Plist hacks: Injecting entries into ~/Library/Audio/MIDI Configurations/*.mcfg works when AMS is closed, but AMS immediately locks and reverts my changes when it’s open. • CoreMIDI C API: I can create virtual ports with MIDISourceCreate, but attempting MIDIObjectGetDataProperty on the apple.midirtp.session plugin always returns err –10836. • Obj-C & Swift: Loading MIDINetworkSession and calling defaultSession, init, setNetworkName: and setting enabled = YES doesn’t produce a new session object in the Network panel. • dlopen/dlsym: I extracted the real CoreMIDI binary out of the dyld shared cache and tried binding _MIDINetworkSessionCreate, _SetName, _SetEnabled, etc., but all the symbols come back null or my tool segfaults. • Plugin registration: I’ve pulled the factory UUID (70C9C5EA-7C65-11D8-B317-000393A34B5A) from /System/Library/Extensions/AppleMIDIRTPDriver.plugin/Contents/Info.plist and called CFPlugInRegisterFactories, but it still never exposes the session-creation calls. At this point I’m convinced I’m either loading the wrong binary or missing one critical step in registering the RTP-MIDI plugin’s private API. Can anyone point me to: The exact path of the dylib or bundle that actually exports the MIDINetworkSessionCreate/MIDINetworkSessionSetName/MIDINetworkSessionSetEnabled symbols? A minimal working snippet (C or Obj-C) that reliably creates and names a Network-MIDI session? Any pointers, sample code, or even ideas about where Apple hides this functionality on macOS 15 would be hugely appreciated. Thanks!

I'm developing an audio player app that uses AVAudio​File to read PCM data from various formats. I'm experiencing severe performance issues when seeking in FLAC, while other compressed formats (M4A/AAC) work correctly. I don't intend to use them in my app, but I also tested mp3 files just by curiosity and they also have this issue. Environment: macOS 26 (Tahoe) Xcode 26.3 Apple Silicon (M1) The issue: After setting AVAudio​File​.frame​Position to a position mid-file, the subsequent call to AVAudio​File​.read(into​:frame​Count:) blocks for an unreasonable amount of time for FLAC and MP3 files. The delay scales linearly with the seek target, seeking near the beginning is fast, seeking toward the end is proportionally slower, which suggests the decoder is decoding linearly from the beginning of the file rather than using any seek index. (My app deals with “images” of Audio CDs ripped as a single long audio file.) The issue is particularly severe when reading files from an SMB network share (server on Ethernet, client on Wi-Fi with the access point ~2 meters away in line of sight). Quick Benchmark results: I tested with the same 75-minute audio content (16-bit/44.1 kHz stereo, 200,502,708 frames) encoded in five formats, seeking to the midpoint. Over SMB (Local Network, Server on Ethernet, Client on WiFi): Format | Seek + Read Time ----------|------------------ WAV | 0.007 s AIFF | 0.009 s Apple | 0.015 s Lossless | MP3 | 9.2 s FLAC | 30.2 s Locally (MacBook Air M1 SSD) : Format | Seek + Read Time ----------|------------------ WAV | 0.0005 s AIFF | 0.0004 s Apple | 0.0011 s Lossless | MP3 | 0.1958 s FLAC | 0.7528 s WAV, AIFF, and M4A all seek virtually instantly (< 15 ms). MP3 and FLAC exhibit linear-time behavior, with FLAC being the worst affected. Note that M4A (AAC) is also a compressed format that requires decoding after seeking, yet it completes in 15 ms. This rules out any inherent limitation of compressed formats, the MP4 container's packet index (stts/stco) is clearly being used for fast random access. Both MP3 (Xing/LAME TOC) and FLAC (SEEKTABLE metadata block) have their own seek mechanisms that should provide similar performance. Minimal CLI tool to reproduce: import Foundation guard CommandLine.arguments.count > 1 else { print("Usage: FLACSpeed <audio-file-path>") exit(1) } let path = CommandLine.arguments[1] let fileURL = URL(fileURLWithPath: path) do { let file = try AVAudioFile(forReading: fileURL) let format = file.processingFormat let buffer = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: 8192)! let totalFrames = file.length let seekTarget = totalFrames / 2 print("File: \(fileURL.lastPathComponent)") print("Format: \(format)") print("Total frames: \(totalFrames)") print("Seeking to frame: \(seekTarget)") file.framePosition = seekTarget let start = CFAbsoluteTimeGetCurrent() try file.read(into: buffer, frameCount: 8192) let elapsed = CFAbsoluteTimeGetCurrent() - start print("Read after seek took \(elapsed) seconds") } catch { print("Error: \(error.localizedDescription)") exit(1) } Expected behavior: AVAudio​File​.read(into​:frame​Count:) after setting frame​Position should use the available seek mechanisms in FLAC and MP3 files for fast random access, as it already does for M4A (AAC). Even accounting for the fact that seek tables provide approximate (not sample-precise) positioning, the "jump to nearest index point + decode forward" approach should complete in milliseconds, not seconds. Workaround: For FLAC, I've worked around this by using libFLAC directly, which provides instant seeking via FLAC__stream​_decoder​_seek​_absolute(). libFLAC Performance: For comparison, libFLAC's FLAC__stream​_decoder​_seek​_absolute() performs the same seek + read on the same FLAC file in around 0.015, using the FLAC seek table to jump to the nearest preceding seek point, then decoding forward a small number of frames to the exact target sample.

Hello everyone, I’m looking for more detailed information regarding UVC (USB Video Class) over MFi within the Apple ecosystem and would appreciate some clarification. I’m interested in developing (or interfacing with) an accessory that transmits video over USB using the UVC standard, and I’d like to better understand how this works within the MFi (Made for iPhone) program. Here are my main questions: 1. Do iOS devices provide native support for UVC over USB-C or Lightning within the MFi framework? 2. Are there any specific firmware or authentication requirements when the accessory is MFi-certified? 3. Does UVC support depend solely on the hardware interface (USB-C vs Lightning), or are there additional software-level requirements? 4. Is there any official documentation outlining the recommended flow for implementing UVC-based video capture accessories on iOS? From what I understand, USB-C iPads appear to offer more direct support for standard UVC devices, but it’s not entirely clear how this integrates with the MFi ecosystem with iOS, especially for commercial product development. If anyone has gone through this process or can point me to relevant technical documentation, I would greatly appreciate the guidance. Thank you!

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

Description: I have identified a specific issue when recording acoustic guitar and other instruments on the iPhone 17 Pro Max using native applications (Voice Memos, Camera). The recordings contain an unnatural metallic resonance (ringing artifacts) that should not be present. Testing and Methodology: Hardware Verification: Initially, I suspected a hardware defect in the audio chip or microphone. However, extensive testing with third-party software suggests this is likely a software-level issue. AudioShare Test: I conducted a test using the AudioShare app in "Measurement Mode" (which bypasses standard iOS system-wide audio processing). In this mode, the audio remains perfectly clean, and the metallic ringing disappears entirely. Conclusion: The issue is rooted in the DSP (Digital Signal Processing) algorithms that iOS applies for noise suppression or voice enhancement. These algorithms appear to misinterpret the high-frequency overtones of acoustic instruments as background noise and attempt to "filter" them, resulting in audible digital artifacts. Comparison Results: This issue has not been observed on devices from other brands or on older iPhone models (preliminary tests suggest older versions handle this better). Notably, the problem persists even in GarageBand, as the app still utilizes certain system-level processing layers. Proposed Solution: I suggest adding a "Raw Audio" or "Instrument Mode" toggle within the Microphone/Audio settings for native apps. This mode should disable aggressive DSP processing, similar to how the AVAudioSession.Mode.measurement works in specialized apps. Attachments: I am attaching 4 archives, including a final "Measurement Mode" folder with comparative samples (Measurement Mode vs. Standard Mode). The artifacts are most prominent when monitored through headphones.

In iOS 26 (Developer Beta), the AVCaptureMetadataOutputObjectsDelegate no longer receives callbacks when metadataOutput.metadataObjectTypes = [.face] is set. On earlier iOS versions the issue does not occur. Interestingly, face detection works if I set the sessionPreset to .medium, but not with .high — except on the iPhone 16 Pro Max, where it works regardless.

Hello, I'm developing an app that displays a photo library using UICollectionView and PHCachingImageManager. I'd like to achieve a user experience similar to the native iOS Photos app, where low-quality images are shown quickly while scrolling, and higher-quality images are loaded for visible cells once scrolling stops. I'm currently using the following approach: While Scrolling: I'm using the UICollectionViewDataSourcePrefetching protocol. In the prefetchItemsAt method, I call startCachingImages with low-quality options to cache images in advance. After Scrolling Stops: In the scrollViewDidEndDecelerating method, I intend to load high-quality images for the currently visible cells. I have a few questions regarding this approach: What is the best practice for managing both low-quality and high-quality images efficiently with PHCachingImageManager? Is it correct to call startCachingImages with fastFormat options and then call it again with highQualityFormat in scrollViewDidEndDecelerating? How can I minimize the delay when a low-quality image is replaced by a high-quality one? Are there any additional strategies to help pre-load high-quality images more effectively?

iOS 26 added smoothness to CIRoundedRectangleGenerator, for use with CIFilter.roundedRectangleGenerator. What should the smoothness value be to achieve the same corner curve as CALayerCornerCurve.continuous? Does it need to be calculated based on the extent size, if so, how?