I have a question regarding the behavior of AVAudioSession.sharedInstance().outputVolume. Observed behavior: When the app is in the foreground, I read audioSession.outputVolume (for example, 0.1). The app is then moved to the background. While the app is in the background, the user changes the system volume using the hardware buttons (for example, to 0.5). When the app returns to the foreground, audioSession.outputVolume still reports the previous value (0.1). From my testing, outputVolume only seems to update when the system volume is changed while the app is in the foreground. Volume changes made while the app is in the background are not reflected when the app returns to the foreground. Questions: According to Apple’s documentation for AVAudioSession.outputVolume: “The systemwide output volume set by the user.” https://developer.apple.com/documentation/avfaudio/avaudiosession/outputvolume However, based on our testing on iOS 18.6.2 and iOS 18.1, the observed behavior seems to differ from this description. Questions: The documentation states that outputVolume represents the system-wide volume set by the user. In our testing, the value does not reflect volume changes made while the app is in the background and only updates when the app is in the foreground.Is this the expected behavior of AVAudioSession.outputVolume? Is there any other recommended way in Swift to retrieve the current system volume that reflects user changes made both while the app is in the foreground and while it is in the background? Any clarification on the intended behavior or recommended handling would be greatly appreciated.

Hello, I have some confusion regarding ResidencySet. Specifically, about the requestResidency() function: how often should we call it? I have a captureOutput(_:didOutput:from:) method that is triggered at 60 or 120 fps. Inside this method, I am calling the following code every frame: computeResidencySet.removeAllAllocations() сomputeResidencySet.addAllocation(TextureA) computeResidencySet.addAllocation(TextureB) computeResidencySet.addAllocation(TextureC) computeResidencySet.commit() computeResidencySet.requestResidency() // Should we call it every frame? Please keep in mind that TextureA, TextureB, and TextureC are unique for each call (new instances are provided on every frame)."

At which point in the image processing pipeline does iOS apply the white balance gains which can be set via AVCaptureDevice.setWhiteBalanceModeLocked(with:completionHandler:)? Are those gains applied in the analog part of the camera pipeline, before the pixel voltage gets converted via the ADC to digital values? Or does the camera first convert the pixel voltages to digital values and then the gains are applied to the digital values? Is this consistent across devices or can the behavior vary from device to device?

Hello, I have a CarPlay Navigation app and utilize the AVSpeechSynthesizer to speak directions to a user. Everything works great on my CarPlay simulator as well as when plugged into my GMC truck. However, I found out yesterday that one of my users with a Ford truck the audio would cut in an out. After much troubleshooting, I was able to replicate this on my own truck when using Bluetooth to connect to CarPlay. My user was also utilizing Bluetooth. Has anyone else experienced this? Is there a fix to the problem? import SwiftUI import AVFoundation class TextToSpeechService: NSObject, ObservableObject, AVSpeechSynthesizerDelegate { private var speechSynthesizer = AVSpeechSynthesizer() static let shared = TextToSpeechService() override init() { super.init() speechSynthesizer.delegate = self } func configureAudioSession() { speechSynthesizer.delegate = self do { try AVAudioSession.sharedInstance().setCategory(.playback, mode: .voicePrompt, options: [.mixWithOthers, .allowBluetooth]) } catch { print("Failed to set audio session category: \(error.localizedDescription)") } } func speak(_ text: String) { Task(priority: .high) { let speechUtterance = AVSpeechUtterance(string: text) speechUtterance.voice = AVSpeechSynthesisVoice(language: AVSpeechSynthesisVoice.currentLanguageCode()) try AVAudioSession.sharedInstance().setActive(true, options: .notifyOthersOnDeactivation) speechSynthesizer.speak(speechUtterance) } } func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) { Task { stopSpeech() try AVAudioSession.sharedInstance().setActive(false) } } func stopSpeech() { speechSynthesizer.stopSpeaking(at: .immediate) } }

Apple provides a function to create TTS voice as a file in TTS. (AVSpeechUtterance/AVSpeechSynthesizer) Or, if the user records the video of TTS playback and uses that video I wonder what the scope of use is if I use this TTS voice to make YouTube, TikTok, or commercial videos. Is it impossible to use it commercially at all? Can I use it commercially with the source indicated? Can I use it commercially without a separate source indication? Is there a difference in commercial use license between Siri voices and regular TTS voices?

Hi! I'd like to share a technical sample app, SKRenderer Demo. This app demonstrates: Setting up SKRenderer Recording SpriteKit scenes to image sequences Recording SpriteKit scenes to video using IOSurface and AVFoundation Applying Core Image filters Exploring SpriteKit's simulation timing and physics determinism Use Case Record SpriteKit simulations as video or images for sharing and creating content. I explored several approaches, including the excellent view.texture(from:crop:) for live recording from SKView. The SKRenderer approach assumes recording happens asynchronously: you capture user interactions as commands during live interaction, then replay those commands through an offline render pass to generate the final output. I hope this helps others working on replay systems, simulation capture, or SpriteKit projects in general!

Environment Device: iPhone 15 Pro iOS: iOS 18.0 Framework: AVFoundation App type: Custom camera app using AVCaptureSession + AVCaptureVideoPreviewLayer I’m seeing an intermittent but frequent issue where the camera preview layer briefly flashes empty after certain interruptions, even though the capture session reports itself as running and no errors are emitted. This happens most often after: Locking and unlocking the device Switching cameras (back ↔ front) The issue is not 100% reproducible, but occurs often enough to be noticeable in normal usage. What happens The preview layer briefly flashes as empty (sometimes just a “micro-frame”) Duration: typically ~0.5–2 seconds before frames resume session.isRunning == true throughout No crash, no runtime error, no interruption end failure Focus/exposure restore correctly once frames resume Visually it looks like the preview layer loses frames temporarily, even though the session appears healthy. Repro Intermittent but frequent after: Lock → unlock device Switching camera (front/back) Timing-dependent and non-deterministic Happens multiple times per session, but not every time Key observation AVCaptureSession.isRunning == true does not guarantee that frames are actually flowing. To verify this, I added an AVCaptureVideoDataOutput temporarily: During the blank period, no sample buffers are delivered Frames resume after ~1–2s without any explicit restart Session state remains “running” the entire time What I’ve tried (did NOT fix it) Adding delays before/after startRunning() (0.1–0.5s) Calling startRunning() on different queues Restarting the session in AVCaptureSessionInterruptionEnded Verifying session.connections (all show isActive == true) Rebuilding inputs/outputs during interruption recovery Ensuring startRunning() is never called between beginConfiguration() / commitConfiguration() (Hit the expected runtime warning when attempted) None of the above removed the brief blank preview. Workaround (works visually but expensive) This visually fixes the issue, but: Energy impact jumps from Low → High in Xcode Energy Gauge AVCaptureVideoDataOutput processes 30–60 FPS continuously The gap only lasts ~1–2s, but toggling the delegate on/off cleanly is difficult Overall CPU and energy cost is not acceptable for production Additional notes CPU usage is already relatively high even without the workaround (this app is camera-heavy by nature) With the workaround enabled, energy impact becomes noticeably worse The issue feels like a timing/state desync between session state and actual frame delivery, not a UI issue Questions Is this a known behavior where AVCaptureSession.isRunning == true but frames are temporarily unavailable after interruptions? Is there a recommended way to detect actual frame flow resumption (not just session state)? Should the AVCaptureVideoPreviewLayer.connection (isActive / isEnabled) be explicitly checked or reset after interruptions? Is there a lightweight, energy-efficient way to bridge this short “no frames” gap without using AVCaptureVideoDataOutput? Is rebuilding the entire session the only reliable solution here, or is there a better pattern Apple recommends?

Hello, I have an iOS camera app that captures exposure brackets and performs custom HDR processing. On iOS 26, I’m observing a visual difference between: a single photo captured at –2 EV, and the –2 EV frame from an exposure bracket (–2 / 0 / +2 EV). On iOS 26: The single –2 EV image looks natural and consistent. The –2 EV image from the bracket appears clamped / distorted, most noticeably in high dynamic range scenes (highlight compression and loss of detail). On iOS 18, both approaches produce visually identical and correct –2 EV images. The issue only appears for bracketed captures on iOS 26. Attachments (examples) iOS 26 Single capture –2 EV (JPEG): /Users/danilobudimir/Downloads/ios26SingleImage/JPEG image-4006-8B77-51-0.jpeg Single capture –2 EV — Capture report (dumped settings): /Users/danilobudimir/Downloads/ios26SingleImage/UnderExposureDebug_CaptureReport_2026-01-09T15-59-20Z.md Bracket capture –2 EV frame (JPEG): /Users/danilobudimir/Downloads/bracket_iOS26/JPEG image-45CE-9793-A5-0.jpeg Bracket capture — Capture report (dumped settings): /Users/danilobudimir/Downloads/bracket_iOS26/UnderExposureDebug_CaptureReport_2026-01-09T15-55-42Z.md iOS 18 Single capture –2 EV (JPEG): /Users/danilobudimir/Downloads/ios18SingleImage/JPEG image-47FD-AF73-28-0.jpeg Single capture –2 EV — Capture report: /Users/danilobudimir/Downloads/ios18SingleImage/UnderExposureDebug_CaptureReport_2026-01-09T16-25-27Z.md Bracket capture — –2 EV frame (JPEG): /Users/danilobudimir/Downloads/bracket_iOS18/JPEG image-4A4C-9E93-46-0.jpeg Bracket capture — Capture report: /Users/danilobudimir/Downloads/bracket_iOS18/UnderExposureDebug_CaptureReport_2026-01-09T16-27-23Z.md Question Is there any new behavior in iOS 26 AVFoundation related to: AVCapturePhotoBracketSettings, tone mapping / HDR preprocessing, or internal image processing applied specifically to bracketed frames? Is there a new flag, format requirement or opt-out mechanism required to preserve linear underexposed frames in exposure brackets?

Looking to implement to UI to tell the user to clean their lens in our app. Implemented the KVO for the cameraLensSmudgeDetectionStatus but I'm having issues reliably triggering it in, both in our app and the main camera app. Tried to get inventive by putting tupperware over the lens, but I think the model driving this or the LiDAR sensor might be smart enough to detect there is something close to the lens. Is there any way to trigger this change in a similar way we can trigger thermal changes in debug? Thanks.

Hello, I am currently considering developing a Full Space app that enables a shared visionOS experience with nearby users. Intended Features A Mixed Full Space app in which dozens of 3D models are placed in the space. These 3D models may play embedded animations when tapped, be programmatically moved or rotated, or be controlled via Reality Composer Pro timelines. The app also includes audio, spatial audio, videos with audio, and videos without audio, which are rendered as VideoTextures on planes and played back in the space. Some media elements play automatically, while others are triggered by user interaction. However, it is unclear whether AVPlaybackCoordinator supports shared playback across multiple types of media, such as: audio only spatial audio video without audio video with audio I am also unsure whether there are alternative or recommended approaches for synchronizing playback in this scenario. Questions Is it technically possible to implement the experience described above using visionOS? Are there any important implementation considerations or limitations that should be taken into account? For example, when two participants experience the app simultaneously, how is the content positioned for each participant? Is the spatial placement of content shared across participants, or is it positioned relative to each participant’s viewpoint? For nearby participants, is it necessary to register a spatial Persona? My understanding is that spatial Personas are not visible for nearby users during the experience; is this correct? When experiencing SharePlay with nearby users, is it possible to share the experience without registering the other participant’s contact information? I have watched the following session, but I was unable to fully understand the feasibility of the above use case or the concrete implementation details: https://developer.apple.com/videos/play/wwdc2025/318/ Thank you.

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!

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'.

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!

Hello, I am developing a custom player SDK using AVPlayer to support HLS and LL-HLS live streaming. I have some questions about the internal logic of AVPlayer regarding ABR, as this information is not explicitly covered in the documentation. ABR Switching Logic: Does AVPlayer trigger bitrate switching primarily based on stall occurrences (buffer starvation)? I am curious if the switching logic is reactive to stalls or if it proactively switches to prevent them based on throughput estimation. Developer Controls for ABR: To influence or control the ABR selection, are preferredPeakBitRate and preferredForwardBufferDuration the only properties available to developers? Are there any other recommended APIs to assist with ABR decisions? Thank you for your help.

Hi everyone, does anybody have any resources I could check out regarding the 48->12mp binning behavior on supported sensors? I know the 48mp sensor on iPhone can automatically bin pixels for better low light performance. But not sure how to reliably make this happen in practice. On iPhone 14 Pro+ with a 48MP sensor, I want the best of both worlds for ProRAW: ∙ Bright light: 48MP full resolution ∙ Low light: 12MP pixel-binned for better noise `photoOutput.maxPhotoDimensions = CMVideoDimensions(width: 8064, height: 6048) let settings = AVCapturePhotoSettings(rawPixelFormatType: proRawFormat, processedFormat: [...]) settings.photoQualityPrioritization = .quality // NOT setting settings.maxPhotoDimensions — always get 12MP` When I omit maxPhotoDimensions, iOS always returns 12MP regardless of lighting. When I set it to 48MP, I always get 48MP. Is there an API to let iOS automatically choose the optimal resolution based on conditions, or should I detect low light myself (via device.iso / exposureDuration) and set maxPhotoDimensions accordingly? Any help or direction would be much appreciated!

Hi everyone, I'm developing a camera application that requires precise, predictable control over the focus system. I'm encountering unexpected behavior with face-driven autofocus in continuous autofocus mode. Issue: When using AVCaptureDevice.FocusMode.continuousAutoFocus, the system continues to prioritize faces for focus even after attempting to disable face-driven autofocus with: device.automaticallyAdjustsFaceDrivenAutoFocusEnabled = false device.isFaceDrivenAutoFocusEnabled = false Observations: The behavior is inconsistent across different scenes. In well-lit/properly exposed scenes: focus persistently locks onto faces, ignoring my configuration. . In underexposed scenes: the intended focus behavior is more consistently respected.

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 everyone, I’m seeing recurring internal AVFoundation camera logs on iOS 26.2 and I’m trying to understand whether this is expected behavior or a regression in the capture pipeline. These logs appear shortly after starting an AVCaptureSession, while video frames are being delivered, and also when the camera is stopped or the capture session is torn down. <<<< FigXPCUtilities >>>> signalled err=-17281 at <>:302 <<<< FigCaptureSourceRemote >>>> Fig assert: "err == 0 " at bail (FigCaptureSourceRemote.m:569) - (err=-17281) Even in this clean, minimal setup, the same logs appear on iOS 26.2 The exact same logic did not produce these logs on iOS 18.x. To rule out issues caused by my own code, GPT created a minimal SwiftUI example from scratch. My primary interest is to perform real-time processing on the video frames delivered by the camera (via AVCaptureVideoDataOutput), for tasks such as analysis, computer vision, or custom frame handling, while simultaneously displaying the live preview. Thanks in advance for any insight. Example Code

I am developing an iOS camera app that can record video directly to external storage connected to an iPhone. To detect whether an external USB storage device is connected and to obtain its URL, I am considering using AVExternalStorageDeviceDiscoverySession. However, when checking support using AVExternalStorageDeviceDiscoverySession.isSupported, I observe that it returns true only on Pro model iPhones, and false on non-Pro models in my environment. I have reviewed Apple’s official documentation, but I could not find any clear description of the supported devices or requirements (for example, whether this API is limited to Pro models or requires specific hardware capabilities). I would appreciate any information regarding the following points: ①The actual requirements for AVExternalStorageDeviceDiscoverySession to be supported Device limitations (Pro vs non-Pro models) Hardware requirements (USB controller, external recording capability, etc.) iOS version dependencies ②Whether support for non-Pro models is planned in the future Tested environments iPhone 16 Pro (iOS 18.7.1) → isSupported == true iPhone 16e (iOS 26.2) → isSupported == false iPhone 17 (iOS 26.2) → isSupported == false iPhone Air (iOS 26.2) → isSupported == false If anyone has observed similar behavior or has official information from Apple regarding this API, I would greatly appreciate your insights.

I am developing an iOS camera app that can record video directly to external storage connected to an iPhone. To detect whether an external USB storage device is connected and to obtain its URL, I am considering using AVExternalStorageDeviceDiscoverySession. However, when checking support using AVExternalStorageDeviceDiscoverySession.isSupported, I observe that it returns true only on Pro model iPhones, and false on non-Pro models in my environment. I have reviewed Apple’s official documentation, but I could not find any clear description of the supported devices or requirements (for example, whether this API is limited to Pro models or requires specific hardware capabilities). I would appreciate any information regarding the following points: ●The actual requirements for AVExternalStorageDeviceDiscoverySession to be supported Device limitations (Pro vs non-Pro models) Hardware requirements (USB controller, external recording capability, etc.) iOS version dependencies ●Whether support for non-Pro models is planned in the future Tested environments iPhone 16 Pro (iOS 18.7.1) → isSupported == true iPhone 16e (iOS 26.2) → isSupported == false iPhone 17 (iOS 26.2) → isSupported == false iPhone Air (iOS 26.2) → isSupported == false If anyone has observed similar behavior or has official information from Apple regarding this API, I would greatly appreciate your insights.