AVFoundation

RSS for tag

Work with audiovisual assets, control device cameras, process audio, and configure system audio interactions using AVFoundation.

Posts under AVFoundation tag

200 Posts

Post

Replies

Boosts

Views

Activity

On iOS26, in our video playback app(use AVPlayer), the sound and video are out of sync when playing after seeking.
Our app plays TS files on an iPhone. The app fragments the TS files, creates an M3U8 playlist, converts them to HLS(HTTP Live Streaming), and then uses AVPlayer to play the video content. On a device running iOS 26, after starting playback and seeking, restarting playback causes the video and audio to be out of sync (by about 2-3 seconds depending on the situation). This also occurs on iPadOS/macOS 26. This issue was not observed prior to iOS 18. We are trying to fix this issue on the app side, but we have the following questions: The behavior of AVPlayer is different between iOS 26 and previous versions. Has there been any change that could be considered? Or is it a bug? We tried pausing before seeking, but it didn’t seem to have any effect. Are there any APIs or workarounds that can improve this? We would appreciate it if you could tell us any other helpful documents or URLs.
0
0
438
Sep ’25
How to use Front UW and TrueDepth in iPad
I want to use both front UW and TrueDepth cameras in iPad which has front UW camera. Firstly, I have used only front builtInDualCamera by AVFoundation and tried all the formats that can be used with builtInDualCamera, but there was no format that could capture UW. Secondly, I have tried to both front builtInDualCamera and builtInUltraWideCamera, but there was no combination that could use builtInUltraWideCamera and builtInDualCamera. Is there any way ?
0
0
170
Sep ’25
Orientation does not work on iPhone 17 and above.
I'm receiving output from avcapturesession and capturing an image using Vision, but the image is output in landscape orientation instead of portrait. Even when I set the orientation to up in ciimage, cgimage, and uiimage, the image is still output in landscape orientation. On iPhones 16 and below, the image is output in portrait orientation. But on iPhones 17 and above, the image is output in landscape orientation. Please help.
1
1
439
Dec ’25
Memory leak on processing stereoscopic video frame, makeMutablePixelBuffer()
Hi, I downloaded and ran https://developer.apple.com/documentation/realitykit/rendering-stereoscopic-video-with-realitykit and noticed that memory usage grows linearly. I replaced the sample video with a different 8k side by side video, and the app crashed almost immediately due to memory leak. it looks like the culprit is from makeMutablePixelBuffer() function and the allocated pixelBuffers are not recycled after being used. screenshot is from a physical device.
0
0
342
Sep ’25
iPhone 17 smart framing api not working
I tried to modify the AVCam sample code by copying the code here https://developer.apple.com/documentation/avfoundation/adopting-smart-framing-in-your-camera-app#Configure-the-smart-framing-monitor smart framing monitors I can ensure the activeformat supports smart framing, but the supported frames in monitor is always nil. In my another project it has supported value, but the observation has never been triggered, then I tried to keep printing the recommended frame, it's always nil. Could the engineer embed the code into AVCam rather than posting a few code pieces?
0
0
165
Sep ’25
Disabling Hardware OIS via AVFoundation — Clarification on AVCaptureVideoStabilizationMode
Hello everyone, I'm looking for a definitive clarification on how to completely disable all video stabilization, including the hardware OIS, using AVFoundation. The goal is to achieve a completely raw, unstabilized video feed, which is crucial when using external equipment like gimbals to avoid conflicting stabilization motions. My research points to using the AVCaptureConnection property preferredVideoStabilizationMode and setting it to AVCaptureVideoStabilizationMode.off. The documentation for the .off case states: A mode that doesn’t stabilize video capture. This description is slightly ambiguous. It's unclear whether this only affects software-level stabilization (EIS, EIS+OIS, etc) or if it guarantees the complete deactivation of the physical OIS module. For professional video applications, this is a critical distinction. So, I'd like to ask the community: Has anyone been able to definitively confirm that setting preferredVideoStabilizationMode to .off also disables the hardware OIS? Are there any known tests or documentation that prove this behavior? Is there an alternative or more direct method to ensure the OIS module is physically inactive during video capture? What is the community's best practice for ensuring absolutely no stabilization is applied to the video pipeline? Any insights or shared experiences on this topic would be greatly appreciated. Thank you!
0
1
314
Sep ’25
-46250 error when calling `makeSecureTokenForExpirationDateOfPersistableContentKey`
Hi there, We're working on offline playback of DRM tracks. The persistent keys (also known as track licenses) for offline playback are stored locally on the device and are served from cache when a user initiates playback of a downloaded track. Our persistent keys have a limited validity time and need to be refreshed when they expire. To prevent a situation where a persistent key expires while the user is offline, we've decided to eagerly refresh these keys one week before their expiration date. To make that happen we need to be able to obtain the expiration date of the given track license. We've been attempting to use the makeSecureTokenForExpirationDateOfPersistableContentKey API to facilitate this process. The documentation states that this API returns a secret token representing the persistent key, which we can then exchange with our license server for the expiration date: https://developer.apple.com/documentation/avfoundation/avcontentkeysession/makesecuretokenforexpirationdate(ofpersistablecontentkey:completionhandler:)?language=objc However, every time we call makeSecureTokenForExpirationDateOfPersistableContentKey, we receive an error with code -46250. We haven't been able to find any public references or documentation for this specific error code, which is preventing us from troubleshooting the issue. We are conducting our tests on a physical device, as the simulator does not support FairPlay playback. We don't use dual expiry approach. Is our understanding of how to obtain the expiration timestamp correct? Are we using the makeSecureTokenForExpirationDateOfPersistableContentKey API as it was intended? What does the -46250 error code mean, and what steps should we take to fix our FairPlay implementation to make this work? Thanks in advance for your assistance.
2
1
389
Jan ’26
Crash iOS 26.0: [__NSSingleObjectArrayI selectedMediaOptionInMediaSelectionGroup:]: unrecognized selector sent to instance
I'm having a crash on an app that plays videos when the users activates close captions. I was able to replicate the issue on an empty project. The crash happens when the AVPlayerLayer is used to instantiate an AVPictureInPictureController These are the example project where I tested the crash: struct ContentView: View { var body: some View { VStack { VideoPlaylistView() } .frame(maxWidth: .infinity, maxHeight: .infinity) .background(Color.black.ignoresSafeArea()) } } class VideoPlaylistViewModel: ObservableObject { // Test with other videos var player: AVPlayer? = AVPlayer(url: URL(string:"https://d2ufudlfb4rsg4.cloudfront.net/newsnation/WIpkLz23h/adaptive/WIpkLz23h_master.m3u8")!) } struct VideoPlaylistView: View { @StateObject var viewModel = VideoPlaylistViewModel() var body: some View { ScrollView { VideoCellView(player: viewModel.player) .onAppear { viewModel.player?.play() } } .scrollTargetBehavior(.paging) .ignoresSafeArea() } } struct VideoCellView: View { let player: AVPlayer? @State var isCCEnabled: Bool = false var body: some View { ZStack { PlayerView(player: player) .accessibilityIdentifier("Player View") } .containerRelativeFrame([.horizontal, .vertical]) .overlay(alignment: .bottom) { Button { player?.currentItem?.asset.loadMediaSelectionGroup(for: .legible) { group,error in if let group { let option = !isCCEnabled ? group.options.first : nil player?.currentItem?.select(option, in: group) isCCEnabled.toggle() } } } label: { Text("Close Captions") .font(.subheadline) .foregroundStyle(isCCEnabled ? .red : .primary) .buttonStyle(.bordered) .padding(8) .background(Color.blue.opacity(0.75)) } .padding(.bottom, 48) .accessibilityIdentifier("Button Close Captions") } } } import Foundation import UIKit import SwiftUI import AVFoundation import AVKit struct PlayerView: UIViewRepresentable { let player: AVPlayer? func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<PlayerView>) { } func makeUIView(context: Context) -> UIView { let view = PlayerUIView() view.playerLayer.player = player view.layer.addSublayer(view.playerLayer) view.layer.backgroundColor = UIColor.red.cgColor view.pipController = AVPictureInPictureController(playerLayer: view.playerLayer) view.pipController?.requiresLinearPlayback = true view.pipController?.canStartPictureInPictureAutomaticallyFromInline = true view.pipController?.delegate = view return view } } class PlayerUIView: UIView, AVPictureInPictureControllerDelegate { let playerLayer = AVPlayerLayer() var pipController: AVPictureInPictureController? override init(frame: CGRect) { super.init(frame: frame) } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func layoutSubviews() { super.layoutSubviews() playerLayer.frame = bounds playerLayer.backgroundColor = UIColor.green.cgColor } func pictureInPictureController(_ pictureInPictureController: AVPictureInPictureController, failedToStartPictureInPictureWithError error: any Error) { print("Error starting Picture in Picture: \(error.localizedDescription)") } } class AppDelegate: NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool { let audioSession = AVAudioSession.sharedInstance() do { try audioSession.setCategory(.playback, mode: .moviePlayback) try audioSession.setActive(true) } catch { print("ERR: \(error.localizedDescription)") } return true } } UITest to make the app crash: final class VideoPlaylistSampleUITests: XCTestCase { func testCrashiOS26ToggleCloseCaptions() throws { let app = XCUIApplication() app.launch() let videoPlayer = app.otherElements["Player View"] XCTAssertTrue(videoPlayer.waitForExistence(timeout: 30)) let closeCaptionButton = app.buttons["Button Close Captions"] for _ in 0..<2000 { closeCaptionButton.tap() } } }
0
5
400
Sep ’25
AVPlayer loading performance problem in iOS 26
Hi, I have an app that displays tens of short (<1mb) mp4 videos stored in a remote server in a vertical UICollectionView that has horizontally scrollable sections. I'm caching all mp4 files on disk after downloading, and I also have a in-memory cache that holds a limited number (around 30) of players. The players I'm using are simple views that wrap an AVPlayerLayer and its AVPlayerItem, along with a few additional UI components. The scrolling performance was good before iOS 26, but with the release of iOS 26, I noticed that there is significant stuttering during scrolling while creating players with a fileUrl. It happens even if use the same video file cached on disk for each cell for testing. I also started getting this kind of log messages after the players are deinitialized: <<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1107 <<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1095 <<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1095 There's also another log message that I see occasionally, but I don't know what triggers it. << FigXPC >> signalled err=-16152 at <>:1683 Is there anyone else that experienced this kind of problem with the latest release? Also, I'm wondering what's the best way to resolve the issue. I could increase the size of the memory cache to something large like 100, but I'm not sure if it is an acceptable solution because: 1- There will be 100 player instance in memory at all times. 2- There will still be stuttering during the initial loading of the videos from the web. Any help is appreciated!
1
0
532
Dec ’25
Blurry Depth Data since iPhone 13
I tested the accuracy of the depth map on iPhone 12, 13, 14, 15, and 16, and found that the variance of the depth map after iPhone 12 is significantly greater than that of iPhone 12. Enabling depth filtering will cause the depth data to be affected by the previous frame, adding more unnecessary noise, especially when the phone is moving. This is not friendly for high-precision reconstruction. I tried to add depth map smoothing in post-processing to solve the problem of large depth map deviation, but the performance is still poor. Is there any depth map smoothing solutions already announced by Apple?
1
0
107
Sep ’25
AudioQueue Output fails playing audio almost immediately?
On macOS Sequoia, I'm having the hardest time getting this basic audio output to work correctly. I'm compiling in XCode using C99, and when I run this, I get audio for a split second, and then nothing, indefinitely. Any ideas what could be going wrong? Here's a minimum code example to demonstrate: #include &lt;AudioToolbox/AudioToolbox.h&gt; #include &lt;stdint.h&gt; #define RENDER_BUFFER_COUNT 2 #define RENDER_FRAMES_PER_BUFFER 128 // mono linear PCM audio data at 48kHz #define RENDER_SAMPLE_RATE 48000 #define RENDER_CHANNEL_COUNT 1 #define RENDER_BUFFER_BYTE_COUNT (RENDER_FRAMES_PER_BUFFER * RENDER_CHANNEL_COUNT * sizeof(f32)) void RenderAudioSaw(float* outBuffer, uint32_t frameCount, uint32_t channelCount) { static bool isInverted = false; float scalar = isInverted ? -1.f : 1.f; for (uint32_t frame = 0; frame &lt; frameCount; ++frame) { for (uint32_t channel = 0; channel &lt; channelCount; ++channel) { // series of ramps, alternating up and down. outBuffer[frame * channelCount + channel] = 0.1f * scalar * ((float)frame / frameCount); } } isInverted = !isInverted; } AudioStreamBasicDescription coreAudioDesc = { 0 }; AudioQueueRef coreAudioQueue = NULL; AudioQueueBufferRef coreAudioBuffers[RENDER_BUFFER_COUNT] = { NULL }; void coreAudioCallback(void* unused, AudioQueueRef queue, AudioQueueBufferRef buffer) { // 0's here indicate no fancy packet magic AudioQueueEnqueueBuffer(queue, buffer, 0, 0); } int main(void) { const UInt32 BytesPerSample = sizeof(float); coreAudioDesc.mSampleRate = RENDER_SAMPLE_RATE; coreAudioDesc.mFormatID = kAudioFormatLinearPCM; coreAudioDesc.mFormatFlags = kLinearPCMFormatFlagIsFloat | kLinearPCMFormatFlagIsPacked; coreAudioDesc.mBytesPerPacket = RENDER_CHANNEL_COUNT * BytesPerSample; coreAudioDesc.mFramesPerPacket = 1; coreAudioDesc.mBytesPerFrame = RENDER_CHANNEL_COUNT * BytesPerSample; coreAudioDesc.mChannelsPerFrame = RENDER_CHANNEL_COUNT; coreAudioDesc.mBitsPerChannel = BytesPerSample * 8; coreAudioQueue = NULL; OSStatus result; // most of the 0 and NULL params here are for compressed sound formats etc. result = AudioQueueNewOutput(&amp;coreAudioDesc, &amp;coreAudioCallback, NULL, 0, 0, 0, &amp;coreAudioQueue); if (result != noErr) { assert(false == "AudioQueueNewOutput failed!"); abort(); } for (int i = 0; i &lt; RENDER_BUFFER_COUNT; ++i) { uint32_t bufferSize = coreAudioDesc.mBytesPerFrame * RENDER_FRAMES_PER_BUFFER; result = AudioQueueAllocateBuffer(coreAudioQueue, bufferSize, &amp;(coreAudioBuffers[i])); if (result != noErr) { assert(false == "AudioQueueAllocateBuffer failed!"); abort(); } } for (int i = 0; i &lt; RENDER_BUFFER_COUNT; ++i) { RenderAudioSaw(coreAudioBuffers[i]-&gt;mAudioData, RENDER_FRAMES_PER_BUFFER, RENDER_CHANNEL_COUNT); coreAudioBuffers[i]-&gt;mAudioDataByteSize = coreAudioBuffers[i]-&gt;mAudioDataBytesCapacity; AudioQueueEnqueueBuffer(coreAudioQueue, coreAudioBuffers[i], 0, 0); } AudioQueueStart(coreAudioQueue, NULL); sleep(10); // some time to hear the audio AudioQueueStop(coreAudioQueue, true); AudioQueueDispose(coreAudioQueue, true); return 0; }
2
0
632
Sep ’25
How can I create my own Genlock hardware for the iPhone 17 Pro?
What options do I have if I don't want to use Blackmagic's Camera ProDock as the external Sync Hardware, but instead I want to create my own USB-C hardware accessory which would show up as an AVExternalSyncDevice on the iPhone 17 Pro? Which protocol does my USB-C device have to implement to show up as an eligible clock device in AVExternalSyncDevice.DiscoverySession?
1
0
887
Sep ’25
The behavior of AVPlayerItem.didPlayToEndTimeNotification is not as expected in iOS 26.
Hello, Environment macOS 15.6.1 / Xcode 26 beta 7 / iOS 26 Beta 9 In a simple AVFoundation video-playback sample, I’m seeing different behavior between iOS 18 and iOS 26 regarding AVPlayerItem.didPlayToEndTimeNotification. I’ve attached a minimal sample below. Please replace videoURL with a valid short video URL. Repro steps Tap “Play” to start playback and let the video finish. The AVPlayerItem.didPlayToEndTimeNotification registered with NotificationCenter should fire, and you should see Play finished. in the console. Without relaunching, tap “Play” again. This is where the issue arises. Observed behavior On iOS 18 and earlier: The video does not play again (it does not restart from the beginning), but AVPlayerItem.didPlayToEndTimeNotification is posted and Play finished. appears in the console. The same happens every time you press “Play”. On iOS 26: Pressing “Play” does not post AVPlayerItem.didPlayToEndTimeNotification. The code path that prints Play finished. is never called (the callback enclosing that line is not invoked again). Building the same program with Xcode 16.4 and running it on an iOS 26 beta device shows the same phenomenon, which suggests there has been a behavioral change for AVPlayerItem.didPlayToEndTimeNotification on iOS 26. I couldn’t find any mention of this in the release notes or API Reference. Because the semantics around AVPlayerItem.didPlayToEndTimeNotification appear to differ, we’re forced to adjust our logic. If there is a way to achieve the iOS 18–style behavior on iOS 26, I would appreciate guidance. Alternatively, if this change is intentional, could you share the reasoning? Is iOS 26 the correct behavior from Apple’s perspective and iOS 18 (and earlier) behavior considered incorrect? Any official clarification would be extremely helpful. import UIKit import AVFoundation final class ViewController: UIViewController { private let videoURL = URL(string: "https://......mp4")! private var player: AVPlayer? private var playerItem: AVPlayerItem? private var playerLayer: AVPlayerLayer? private var observeForComplete: NSObjectProtocol? // UI private let playerContainerView = UIView() private let playButton = UIButton(type: .system) private let stopButton = UIButton(type: .system) private let replayButton = UIButton(type: .system) deinit { if let observeForComplete { NotificationCenter.default.removeObserver(observeForComplete) } } override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .systemBackground setupUI() setupPlayer() } override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() playerLayer?.frame = playerContainerView.bounds } // MARK: - Setup private func setupUI() { playerContainerView.translatesAutoresizingMaskIntoConstraints = false playerContainerView.backgroundColor = .black view.addSubview(playerContainerView) // Buttons playButton.setTitle("Play", for: .normal) stopButton.setTitle("Pause", for: .normal) replayButton.setTitle("RePlay", for: .normal) [playButton, stopButton, replayButton].forEach { $0.titleLabel?.font = .systemFont(ofSize: 16, weight: .semibold) $0.translatesAutoresizingMaskIntoConstraints = false $0.contentEdgeInsets = UIEdgeInsets(top: 10, left: 16, bottom: 10, right: 16) } let stack = UIStackView(arrangedSubviews: [playButton, stopButton, replayButton]) stack.axis = .horizontal stack.spacing = 16 stack.alignment = .center stack.distribution = .equalCentering stack.translatesAutoresizingMaskIntoConstraints = false view.addSubview(stack) NSLayoutConstraint.activate([ playerContainerView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20), playerContainerView.leadingAnchor.constraint(equalTo: view.leadingAnchor), playerContainerView.trailingAnchor.constraint(equalTo: view.trailingAnchor), playerContainerView.heightAnchor.constraint(equalToConstant: 200), stack.topAnchor.constraint(equalTo: playerContainerView.bottomAnchor, constant: 20), stack.centerXAnchor.constraint(equalTo: view.centerXAnchor) ]) // Action playButton.addTarget(self, action: #selector(didTapPlay), for: .touchUpInside) stopButton.addTarget(self, action: #selector(didTapStop), for: .touchUpInside) replayButton.addTarget(self, action: #selector(didTapReplayFromStart), for: .touchUpInside) } private func setupPlayer() { // AVURLAsset -> AVPlayerItem → AVPlayer let asset = AVURLAsset(url: videoURL) let item = AVPlayerItem(asset: asset) self.playerItem = item let player = AVPlayer(playerItem: item) player.automaticallyWaitsToMinimizeStalling = true self.player = player let layer = AVPlayerLayer(player: player) layer.videoGravity = .resizeAspect playerContainerView.layer.addSublayer(layer) layer.frame = playerContainerView.bounds self.playerLayer = layer // Notification if let observeForComplete { NotificationCenter.default.removeObserver(observeForComplete) } if let playerItem { observeForComplete = NotificationCenter.default.addObserver( forName: AVPlayerItem.didPlayToEndTimeNotification, object: playerItem, queue: .main ) { [weak self] _ in guard self != nil else { return } Task { @MainActor in print("Play finished.") } } } } // MARK: - Actions @objc private func didTapPlay() { player?.play() } @objc private func didTapStop() { player?.pause() } // RePlay @objc private func didTapReplayFromStart() { player?.seek(to: .zero, toleranceBefore: .zero, toleranceAfter: .zero) { [weak self] _ in self?.player?.play() } } } I would greatly appreciate an official response from Apple engineering on whether this is an intentional change, a regression, or an API contract clarification, and what the recommended approach is going forward. Thank you.
2
3
870
Sep ’25
Threading guarantees with AVCaptureVideoDataOutput
I'm writing some camera functionality that uses AVCaptureVideoDataOutput. I've set it up so that it calls my AVCaptureVideoDataOutputSampleBufferDelegate on a background thread, by making my own dispatch_queue and configuring the AVCaptureVideoDataOutput. My question is then, if I configure my AVCaptureSession differently, or even stop it altogether, is this guaranteed to flush all pending jobs on my background thread? For example, does [AVCaptureSession stopRunning] imply a blocking call until all pending frame-callbacks are done? I have a more practical example below, showing how I am accessing something from the foreground thread from the background thread, but I wonder when/how it's safe to clean up that resource. I have setup similar to the following: // Foreground thread logic dispatch_queue_t queue = dispatch_queue_create("qt_avf_camera_queue", nullptr); AVCaptureSession *captureSession = [[AVCaptureSession alloc] init]; setupInputDevice(captureSession); // Connects the AVCaptureDevice... // Store some arbitrary data to be attached to the frame, stored on the foreground thread FrameMetaData frameMetaData = ...; MySampleBufferDelegate *sampleBufferDelegate = [MySampleBufferDelegate alloc]; // Capture frameMetaData by reference in lambda [sampleBufferDelegate setFrameMetaDataGetter: [&frameMetaData]() { return &frameMetaData; }]; AVCaptureVideoDataOutput *captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init]; [captureVideoDataOutput setSampleBufferDelegate:sampleBufferDelegate queue:queue]; [captureSession addOutput:captureVideoDataOutput]; [captureSession startRunning]; [captureSession stopRunning]; // Is it now safe to destroy frameMetaData, or do we need manual barrier? And then in MySampleBufferDelegate: - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // Invokes the callback set above FrameMetaData *frameMetaData = frameMetaDataGetter(); emitSampleBuffer(sampleBuffer, frameMetaData); }
2
0
451
Sep ’25
Threading guarantees with AVCaptureVideoDataOutput
I'm writing some camera functionality that uses AVCaptureVideoDataOutput. I've set it up so that it calls my AVCaptureVideoDataOutputSampleBufferDelegate on a background thread, by making my own dispatch_queue and configuring the AVCaptureVideoDataOutput. My question is then, if I configure my AVCaptureSession differently, or even stop it altogether, is this guaranteed to flush all pending jobs on my background thread? I have a more practical example below, showing how I am accessing something from the foreground thread from the background thread, but I wonder when/how it's safe to clean up that resource. I have setup similar to the following: // Foreground thread logic dispatch_queue_t queue = dispatch_queue_create("avf_camera_queue", nullptr); AVCaptureSession *captureSession = [[AVCaptureSession alloc] init]; setupInputDevice(captureSession); // Connects the AVCaptureDevice... // Store some arbitrary data to be attached to the frame, stored on the foreground thread FrameMetaData frameMetaData = ...; MySampleBufferDelegate *sampleBufferDelegate = [MySampleBufferDelegate alloc]; // Capture frameMetaData by reference in lambda [sampleBufferDelegate setFrameMetaDataGetter: [&frameMetaData]() { return &frameMetaData; }]; AVCaptureVideoDataOutput *captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init]; [captureVideoDataOutput setSampleBufferDelegate:sampleBufferDelegate queue:queue]; [captureSession addOutput:captureVideoDataOutput]; [captureSession startRunning]; [captureSession stopRunning]; // Is it now safe to destroy frameMetaData, or do we need manual barrier? And then in MySampleBufferDelegate: - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // Invokes the callback set above FrameMetaData *frameMetaData = frameMetaDataGetter(); emitSampleBuffer(sampleBuffer, frameMetaData); }
0
0
362
Sep ’25
Why does AVAudioRecorder show 8 kHz when iPhone hardware is 48 kHz?
Hi everyone, I’m testing audio recording on an iPhone 15 Plus using AVFoundation. Here’s a simplified version of my setup: let settings: [String: Any] = [ AVFormatIDKey: Int(kAudioFormatLinearPCM), AVSampleRateKey: 8000, AVNumberOfChannelsKey: 1, AVLinearPCMBitDepthKey: 16, AVLinearPCMIsFloatKey: false ] audioRecorder = try AVAudioRecorder(url: fileURL, settings: settings) audioRecorder?.record() When I check the recorded file’s sample rate, it logs: Actual sample rate: 8000.0 However, when I inspect the hardware sample rate: try session.setCategory(.playAndRecord, mode: .default) try session.setActive(true) print("Hardware sample rate:", session.sampleRate) I consistently get: `Hardware sample rate: 48000.0 My questions are: Is the iPhone mic actually capturing at 8 kHz, or is it recording at 48 kHz and then downsampling to 8 kHz internally? Is there any way to force the hardware to record natively at 8 kHz? If not, what’s the recommended approach for telephony-quality audio (true 8 kHz) on iOS devices? Thanks in advance for your guidance!
1
0
278
Sep ’25
On iOS26, in our video playback app(use AVPlayer), the sound and video are out of sync when playing after seeking.
Our app plays TS files on an iPhone. The app fragments the TS files, creates an M3U8 playlist, converts them to HLS(HTTP Live Streaming), and then uses AVPlayer to play the video content. On a device running iOS 26, after starting playback and seeking, restarting playback causes the video and audio to be out of sync (by about 2-3 seconds depending on the situation). This also occurs on iPadOS/macOS 26. This issue was not observed prior to iOS 18. We are trying to fix this issue on the app side, but we have the following questions: The behavior of AVPlayer is different between iOS 26 and previous versions. Has there been any change that could be considered? Or is it a bug? We tried pausing before seeking, but it didn’t seem to have any effect. Are there any APIs or workarounds that can improve this? We would appreciate it if you could tell us any other helpful documents or URLs.
Replies
0
Boosts
0
Views
438
Activity
Sep ’25
How to use Front UW and TrueDepth in iPad
I want to use both front UW and TrueDepth cameras in iPad which has front UW camera. Firstly, I have used only front builtInDualCamera by AVFoundation and tried all the formats that can be used with builtInDualCamera, but there was no format that could capture UW. Secondly, I have tried to both front builtInDualCamera and builtInUltraWideCamera, but there was no combination that could use builtInUltraWideCamera and builtInDualCamera. Is there any way ?
Replies
0
Boosts
0
Views
170
Activity
Sep ’25
iOS 26 DRM Content Downloading issue
In iOS 26 When we download any DRM content first time it is downloading again when we edit audios and Video Quality and start downloading it is freezing complete app. Neither it is crashing not giving any error.
Replies
0
Boosts
0
Views
140
Activity
Sep ’25
Orientation does not work on iPhone 17 and above.
I'm receiving output from avcapturesession and capturing an image using Vision, but the image is output in landscape orientation instead of portrait. Even when I set the orientation to up in ciimage, cgimage, and uiimage, the image is still output in landscape orientation. On iPhones 16 and below, the image is output in portrait orientation. But on iPhones 17 and above, the image is output in landscape orientation. Please help.
Replies
1
Boosts
1
Views
439
Activity
Dec ’25
Starting with iPhone 17, the output image of avcapturesession is displayed horizontally.
For iPhones 16 and below, orientation is applied in UIImage or CIImage, but not for iPhone 17. The camera is front-facing, and it uses Vision to capture facial images. Thanks for your help.
Replies
1
Boosts
0
Views
285
Activity
Sep ’25
Memory leak on processing stereoscopic video frame, makeMutablePixelBuffer()
Hi, I downloaded and ran https://developer.apple.com/documentation/realitykit/rendering-stereoscopic-video-with-realitykit and noticed that memory usage grows linearly. I replaced the sample video with a different 8k side by side video, and the app crashed almost immediately due to memory leak. it looks like the culprit is from makeMutablePixelBuffer() function and the allocated pixelBuffers are not recycled after being used. screenshot is from a physical device.
Replies
0
Boosts
0
Views
342
Activity
Sep ’25
iPhone 17 smart framing api not working
I tried to modify the AVCam sample code by copying the code here https://developer.apple.com/documentation/avfoundation/adopting-smart-framing-in-your-camera-app#Configure-the-smart-framing-monitor smart framing monitors I can ensure the activeformat supports smart framing, but the supported frames in monitor is always nil. In my another project it has supported value, but the observation has never been triggered, then I tried to keep printing the recommended frame, it's always nil. Could the engineer embed the code into AVCam rather than posting a few code pieces?
Replies
0
Boosts
0
Views
165
Activity
Sep ’25
Disabling Hardware OIS via AVFoundation — Clarification on AVCaptureVideoStabilizationMode
Hello everyone, I'm looking for a definitive clarification on how to completely disable all video stabilization, including the hardware OIS, using AVFoundation. The goal is to achieve a completely raw, unstabilized video feed, which is crucial when using external equipment like gimbals to avoid conflicting stabilization motions. My research points to using the AVCaptureConnection property preferredVideoStabilizationMode and setting it to AVCaptureVideoStabilizationMode.off. The documentation for the .off case states: A mode that doesn’t stabilize video capture. This description is slightly ambiguous. It's unclear whether this only affects software-level stabilization (EIS, EIS+OIS, etc) or if it guarantees the complete deactivation of the physical OIS module. For professional video applications, this is a critical distinction. So, I'd like to ask the community: Has anyone been able to definitively confirm that setting preferredVideoStabilizationMode to .off also disables the hardware OIS? Are there any known tests or documentation that prove this behavior? Is there an alternative or more direct method to ensure the OIS module is physically inactive during video capture? What is the community's best practice for ensuring absolutely no stabilization is applied to the video pipeline? Any insights or shared experiences on this topic would be greatly appreciated. Thank you!
Replies
0
Boosts
1
Views
314
Activity
Sep ’25
-46250 error when calling `makeSecureTokenForExpirationDateOfPersistableContentKey`
Hi there, We're working on offline playback of DRM tracks. The persistent keys (also known as track licenses) for offline playback are stored locally on the device and are served from cache when a user initiates playback of a downloaded track. Our persistent keys have a limited validity time and need to be refreshed when they expire. To prevent a situation where a persistent key expires while the user is offline, we've decided to eagerly refresh these keys one week before their expiration date. To make that happen we need to be able to obtain the expiration date of the given track license. We've been attempting to use the makeSecureTokenForExpirationDateOfPersistableContentKey API to facilitate this process. The documentation states that this API returns a secret token representing the persistent key, which we can then exchange with our license server for the expiration date: https://developer.apple.com/documentation/avfoundation/avcontentkeysession/makesecuretokenforexpirationdate(ofpersistablecontentkey:completionhandler:)?language=objc However, every time we call makeSecureTokenForExpirationDateOfPersistableContentKey, we receive an error with code -46250. We haven't been able to find any public references or documentation for this specific error code, which is preventing us from troubleshooting the issue. We are conducting our tests on a physical device, as the simulator does not support FairPlay playback. We don't use dual expiry approach. Is our understanding of how to obtain the expiration timestamp correct? Are we using the makeSecureTokenForExpirationDateOfPersistableContentKey API as it was intended? What does the -46250 error code mean, and what steps should we take to fix our FairPlay implementation to make this work? Thanks in advance for your assistance.
Replies
2
Boosts
1
Views
389
Activity
Jan ’26
Has the `externalMetadata` property of `AVPlayerItem` been removed?
(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'
Replies
5
Boosts
0
Views
278
Activity
Sep ’25
Crash iOS 26.0: [__NSSingleObjectArrayI selectedMediaOptionInMediaSelectionGroup:]: unrecognized selector sent to instance
I'm having a crash on an app that plays videos when the users activates close captions. I was able to replicate the issue on an empty project. The crash happens when the AVPlayerLayer is used to instantiate an AVPictureInPictureController These are the example project where I tested the crash: struct ContentView: View { var body: some View { VStack { VideoPlaylistView() } .frame(maxWidth: .infinity, maxHeight: .infinity) .background(Color.black.ignoresSafeArea()) } } class VideoPlaylistViewModel: ObservableObject { // Test with other videos var player: AVPlayer? = AVPlayer(url: URL(string:"https://d2ufudlfb4rsg4.cloudfront.net/newsnation/WIpkLz23h/adaptive/WIpkLz23h_master.m3u8")!) } struct VideoPlaylistView: View { @StateObject var viewModel = VideoPlaylistViewModel() var body: some View { ScrollView { VideoCellView(player: viewModel.player) .onAppear { viewModel.player?.play() } } .scrollTargetBehavior(.paging) .ignoresSafeArea() } } struct VideoCellView: View { let player: AVPlayer? @State var isCCEnabled: Bool = false var body: some View { ZStack { PlayerView(player: player) .accessibilityIdentifier("Player View") } .containerRelativeFrame([.horizontal, .vertical]) .overlay(alignment: .bottom) { Button { player?.currentItem?.asset.loadMediaSelectionGroup(for: .legible) { group,error in if let group { let option = !isCCEnabled ? group.options.first : nil player?.currentItem?.select(option, in: group) isCCEnabled.toggle() } } } label: { Text("Close Captions") .font(.subheadline) .foregroundStyle(isCCEnabled ? .red : .primary) .buttonStyle(.bordered) .padding(8) .background(Color.blue.opacity(0.75)) } .padding(.bottom, 48) .accessibilityIdentifier("Button Close Captions") } } } import Foundation import UIKit import SwiftUI import AVFoundation import AVKit struct PlayerView: UIViewRepresentable { let player: AVPlayer? func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<PlayerView>) { } func makeUIView(context: Context) -> UIView { let view = PlayerUIView() view.playerLayer.player = player view.layer.addSublayer(view.playerLayer) view.layer.backgroundColor = UIColor.red.cgColor view.pipController = AVPictureInPictureController(playerLayer: view.playerLayer) view.pipController?.requiresLinearPlayback = true view.pipController?.canStartPictureInPictureAutomaticallyFromInline = true view.pipController?.delegate = view return view } } class PlayerUIView: UIView, AVPictureInPictureControllerDelegate { let playerLayer = AVPlayerLayer() var pipController: AVPictureInPictureController? override init(frame: CGRect) { super.init(frame: frame) } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func layoutSubviews() { super.layoutSubviews() playerLayer.frame = bounds playerLayer.backgroundColor = UIColor.green.cgColor } func pictureInPictureController(_ pictureInPictureController: AVPictureInPictureController, failedToStartPictureInPictureWithError error: any Error) { print("Error starting Picture in Picture: \(error.localizedDescription)") } } class AppDelegate: NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool { let audioSession = AVAudioSession.sharedInstance() do { try audioSession.setCategory(.playback, mode: .moviePlayback) try audioSession.setActive(true) } catch { print("ERR: \(error.localizedDescription)") } return true } } UITest to make the app crash: final class VideoPlaylistSampleUITests: XCTestCase { func testCrashiOS26ToggleCloseCaptions() throws { let app = XCUIApplication() app.launch() let videoPlayer = app.otherElements["Player View"] XCTAssertTrue(videoPlayer.waitForExistence(timeout: 30)) let closeCaptionButton = app.buttons["Button Close Captions"] for _ in 0..<2000 { closeCaptionButton.tap() } } }
Replies
0
Boosts
5
Views
400
Activity
Sep ’25
AVPlayer loading performance problem in iOS 26
Hi, I have an app that displays tens of short (<1mb) mp4 videos stored in a remote server in a vertical UICollectionView that has horizontally scrollable sections. I'm caching all mp4 files on disk after downloading, and I also have a in-memory cache that holds a limited number (around 30) of players. The players I'm using are simple views that wrap an AVPlayerLayer and its AVPlayerItem, along with a few additional UI components. The scrolling performance was good before iOS 26, but with the release of iOS 26, I noticed that there is significant stuttering during scrolling while creating players with a fileUrl. It happens even if use the same video file cached on disk for each cell for testing. I also started getting this kind of log messages after the players are deinitialized: <<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1107 <<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1095 <<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1095 There's also another log message that I see occasionally, but I don't know what triggers it. << FigXPC >> signalled err=-16152 at <>:1683 Is there anyone else that experienced this kind of problem with the latest release? Also, I'm wondering what's the best way to resolve the issue. I could increase the size of the memory cache to something large like 100, but I'm not sure if it is an acceptable solution because: 1- There will be 100 player instance in memory at all times. 2- There will still be stuttering during the initial loading of the videos from the web. Any help is appreciated!
Replies
1
Boosts
0
Views
532
Activity
Dec ’25
Blurry Depth Data since iPhone 13
I tested the accuracy of the depth map on iPhone 12, 13, 14, 15, and 16, and found that the variance of the depth map after iPhone 12 is significantly greater than that of iPhone 12. Enabling depth filtering will cause the depth data to be affected by the previous frame, adding more unnecessary noise, especially when the phone is moving. This is not friendly for high-precision reconstruction. I tried to add depth map smoothing in post-processing to solve the problem of large depth map deviation, but the performance is still poor. Is there any depth map smoothing solutions already announced by Apple?
Replies
1
Boosts
0
Views
107
Activity
Sep ’25
AudioQueue Output fails playing audio almost immediately?
On macOS Sequoia, I'm having the hardest time getting this basic audio output to work correctly. I'm compiling in XCode using C99, and when I run this, I get audio for a split second, and then nothing, indefinitely. Any ideas what could be going wrong? Here's a minimum code example to demonstrate: #include &lt;AudioToolbox/AudioToolbox.h&gt; #include &lt;stdint.h&gt; #define RENDER_BUFFER_COUNT 2 #define RENDER_FRAMES_PER_BUFFER 128 // mono linear PCM audio data at 48kHz #define RENDER_SAMPLE_RATE 48000 #define RENDER_CHANNEL_COUNT 1 #define RENDER_BUFFER_BYTE_COUNT (RENDER_FRAMES_PER_BUFFER * RENDER_CHANNEL_COUNT * sizeof(f32)) void RenderAudioSaw(float* outBuffer, uint32_t frameCount, uint32_t channelCount) { static bool isInverted = false; float scalar = isInverted ? -1.f : 1.f; for (uint32_t frame = 0; frame &lt; frameCount; ++frame) { for (uint32_t channel = 0; channel &lt; channelCount; ++channel) { // series of ramps, alternating up and down. outBuffer[frame * channelCount + channel] = 0.1f * scalar * ((float)frame / frameCount); } } isInverted = !isInverted; } AudioStreamBasicDescription coreAudioDesc = { 0 }; AudioQueueRef coreAudioQueue = NULL; AudioQueueBufferRef coreAudioBuffers[RENDER_BUFFER_COUNT] = { NULL }; void coreAudioCallback(void* unused, AudioQueueRef queue, AudioQueueBufferRef buffer) { // 0's here indicate no fancy packet magic AudioQueueEnqueueBuffer(queue, buffer, 0, 0); } int main(void) { const UInt32 BytesPerSample = sizeof(float); coreAudioDesc.mSampleRate = RENDER_SAMPLE_RATE; coreAudioDesc.mFormatID = kAudioFormatLinearPCM; coreAudioDesc.mFormatFlags = kLinearPCMFormatFlagIsFloat | kLinearPCMFormatFlagIsPacked; coreAudioDesc.mBytesPerPacket = RENDER_CHANNEL_COUNT * BytesPerSample; coreAudioDesc.mFramesPerPacket = 1; coreAudioDesc.mBytesPerFrame = RENDER_CHANNEL_COUNT * BytesPerSample; coreAudioDesc.mChannelsPerFrame = RENDER_CHANNEL_COUNT; coreAudioDesc.mBitsPerChannel = BytesPerSample * 8; coreAudioQueue = NULL; OSStatus result; // most of the 0 and NULL params here are for compressed sound formats etc. result = AudioQueueNewOutput(&amp;coreAudioDesc, &amp;coreAudioCallback, NULL, 0, 0, 0, &amp;coreAudioQueue); if (result != noErr) { assert(false == "AudioQueueNewOutput failed!"); abort(); } for (int i = 0; i &lt; RENDER_BUFFER_COUNT; ++i) { uint32_t bufferSize = coreAudioDesc.mBytesPerFrame * RENDER_FRAMES_PER_BUFFER; result = AudioQueueAllocateBuffer(coreAudioQueue, bufferSize, &amp;(coreAudioBuffers[i])); if (result != noErr) { assert(false == "AudioQueueAllocateBuffer failed!"); abort(); } } for (int i = 0; i &lt; RENDER_BUFFER_COUNT; ++i) { RenderAudioSaw(coreAudioBuffers[i]-&gt;mAudioData, RENDER_FRAMES_PER_BUFFER, RENDER_CHANNEL_COUNT); coreAudioBuffers[i]-&gt;mAudioDataByteSize = coreAudioBuffers[i]-&gt;mAudioDataBytesCapacity; AudioQueueEnqueueBuffer(coreAudioQueue, coreAudioBuffers[i], 0, 0); } AudioQueueStart(coreAudioQueue, NULL); sleep(10); // some time to hear the audio AudioQueueStop(coreAudioQueue, true); AudioQueueDispose(coreAudioQueue, true); return 0; }
Replies
2
Boosts
0
Views
632
Activity
Sep ’25
How can I create my own Genlock hardware for the iPhone 17 Pro?
What options do I have if I don't want to use Blackmagic's Camera ProDock as the external Sync Hardware, but instead I want to create my own USB-C hardware accessory which would show up as an AVExternalSyncDevice on the iPhone 17 Pro? Which protocol does my USB-C device have to implement to show up as an eligible clock device in AVExternalSyncDevice.DiscoverySession?
Replies
1
Boosts
0
Views
887
Activity
Sep ’25
iPhone 17 Pro's Genlock feature
Where can I find the documentation of the Genlock feature of the iPhone 17 Pro? How does it work and how can I use it in my app?
Replies
7
Boosts
4
Views
1.9k
Activity
Oct ’25
The behavior of AVPlayerItem.didPlayToEndTimeNotification is not as expected in iOS 26.
Hello, Environment macOS 15.6.1 / Xcode 26 beta 7 / iOS 26 Beta 9 In a simple AVFoundation video-playback sample, I’m seeing different behavior between iOS 18 and iOS 26 regarding AVPlayerItem.didPlayToEndTimeNotification. I’ve attached a minimal sample below. Please replace videoURL with a valid short video URL. Repro steps Tap “Play” to start playback and let the video finish. The AVPlayerItem.didPlayToEndTimeNotification registered with NotificationCenter should fire, and you should see Play finished. in the console. Without relaunching, tap “Play” again. This is where the issue arises. Observed behavior On iOS 18 and earlier: The video does not play again (it does not restart from the beginning), but AVPlayerItem.didPlayToEndTimeNotification is posted and Play finished. appears in the console. The same happens every time you press “Play”. On iOS 26: Pressing “Play” does not post AVPlayerItem.didPlayToEndTimeNotification. The code path that prints Play finished. is never called (the callback enclosing that line is not invoked again). Building the same program with Xcode 16.4 and running it on an iOS 26 beta device shows the same phenomenon, which suggests there has been a behavioral change for AVPlayerItem.didPlayToEndTimeNotification on iOS 26. I couldn’t find any mention of this in the release notes or API Reference. Because the semantics around AVPlayerItem.didPlayToEndTimeNotification appear to differ, we’re forced to adjust our logic. If there is a way to achieve the iOS 18–style behavior on iOS 26, I would appreciate guidance. Alternatively, if this change is intentional, could you share the reasoning? Is iOS 26 the correct behavior from Apple’s perspective and iOS 18 (and earlier) behavior considered incorrect? Any official clarification would be extremely helpful. import UIKit import AVFoundation final class ViewController: UIViewController { private let videoURL = URL(string: "https://......mp4")! private var player: AVPlayer? private var playerItem: AVPlayerItem? private var playerLayer: AVPlayerLayer? private var observeForComplete: NSObjectProtocol? // UI private let playerContainerView = UIView() private let playButton = UIButton(type: .system) private let stopButton = UIButton(type: .system) private let replayButton = UIButton(type: .system) deinit { if let observeForComplete { NotificationCenter.default.removeObserver(observeForComplete) } } override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .systemBackground setupUI() setupPlayer() } override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() playerLayer?.frame = playerContainerView.bounds } // MARK: - Setup private func setupUI() { playerContainerView.translatesAutoresizingMaskIntoConstraints = false playerContainerView.backgroundColor = .black view.addSubview(playerContainerView) // Buttons playButton.setTitle("Play", for: .normal) stopButton.setTitle("Pause", for: .normal) replayButton.setTitle("RePlay", for: .normal) [playButton, stopButton, replayButton].forEach { $0.titleLabel?.font = .systemFont(ofSize: 16, weight: .semibold) $0.translatesAutoresizingMaskIntoConstraints = false $0.contentEdgeInsets = UIEdgeInsets(top: 10, left: 16, bottom: 10, right: 16) } let stack = UIStackView(arrangedSubviews: [playButton, stopButton, replayButton]) stack.axis = .horizontal stack.spacing = 16 stack.alignment = .center stack.distribution = .equalCentering stack.translatesAutoresizingMaskIntoConstraints = false view.addSubview(stack) NSLayoutConstraint.activate([ playerContainerView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20), playerContainerView.leadingAnchor.constraint(equalTo: view.leadingAnchor), playerContainerView.trailingAnchor.constraint(equalTo: view.trailingAnchor), playerContainerView.heightAnchor.constraint(equalToConstant: 200), stack.topAnchor.constraint(equalTo: playerContainerView.bottomAnchor, constant: 20), stack.centerXAnchor.constraint(equalTo: view.centerXAnchor) ]) // Action playButton.addTarget(self, action: #selector(didTapPlay), for: .touchUpInside) stopButton.addTarget(self, action: #selector(didTapStop), for: .touchUpInside) replayButton.addTarget(self, action: #selector(didTapReplayFromStart), for: .touchUpInside) } private func setupPlayer() { // AVURLAsset -> AVPlayerItem → AVPlayer let asset = AVURLAsset(url: videoURL) let item = AVPlayerItem(asset: asset) self.playerItem = item let player = AVPlayer(playerItem: item) player.automaticallyWaitsToMinimizeStalling = true self.player = player let layer = AVPlayerLayer(player: player) layer.videoGravity = .resizeAspect playerContainerView.layer.addSublayer(layer) layer.frame = playerContainerView.bounds self.playerLayer = layer // Notification if let observeForComplete { NotificationCenter.default.removeObserver(observeForComplete) } if let playerItem { observeForComplete = NotificationCenter.default.addObserver( forName: AVPlayerItem.didPlayToEndTimeNotification, object: playerItem, queue: .main ) { [weak self] _ in guard self != nil else { return } Task { @MainActor in print("Play finished.") } } } } // MARK: - Actions @objc private func didTapPlay() { player?.play() } @objc private func didTapStop() { player?.pause() } // RePlay @objc private func didTapReplayFromStart() { player?.seek(to: .zero, toleranceBefore: .zero, toleranceAfter: .zero) { [weak self] _ in self?.player?.play() } } } I would greatly appreciate an official response from Apple engineering on whether this is an intentional change, a regression, or an API contract clarification, and what the recommended approach is going forward. Thank you.
Replies
2
Boosts
3
Views
870
Activity
Sep ’25
Threading guarantees with AVCaptureVideoDataOutput
I'm writing some camera functionality that uses AVCaptureVideoDataOutput. I've set it up so that it calls my AVCaptureVideoDataOutputSampleBufferDelegate on a background thread, by making my own dispatch_queue and configuring the AVCaptureVideoDataOutput. My question is then, if I configure my AVCaptureSession differently, or even stop it altogether, is this guaranteed to flush all pending jobs on my background thread? For example, does [AVCaptureSession stopRunning] imply a blocking call until all pending frame-callbacks are done? I have a more practical example below, showing how I am accessing something from the foreground thread from the background thread, but I wonder when/how it's safe to clean up that resource. I have setup similar to the following: // Foreground thread logic dispatch_queue_t queue = dispatch_queue_create("qt_avf_camera_queue", nullptr); AVCaptureSession *captureSession = [[AVCaptureSession alloc] init]; setupInputDevice(captureSession); // Connects the AVCaptureDevice... // Store some arbitrary data to be attached to the frame, stored on the foreground thread FrameMetaData frameMetaData = ...; MySampleBufferDelegate *sampleBufferDelegate = [MySampleBufferDelegate alloc]; // Capture frameMetaData by reference in lambda [sampleBufferDelegate setFrameMetaDataGetter: [&frameMetaData]() { return &frameMetaData; }]; AVCaptureVideoDataOutput *captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init]; [captureVideoDataOutput setSampleBufferDelegate:sampleBufferDelegate queue:queue]; [captureSession addOutput:captureVideoDataOutput]; [captureSession startRunning]; [captureSession stopRunning]; // Is it now safe to destroy frameMetaData, or do we need manual barrier? And then in MySampleBufferDelegate: - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // Invokes the callback set above FrameMetaData *frameMetaData = frameMetaDataGetter(); emitSampleBuffer(sampleBuffer, frameMetaData); }
Replies
2
Boosts
0
Views
451
Activity
Sep ’25
Threading guarantees with AVCaptureVideoDataOutput
I'm writing some camera functionality that uses AVCaptureVideoDataOutput. I've set it up so that it calls my AVCaptureVideoDataOutputSampleBufferDelegate on a background thread, by making my own dispatch_queue and configuring the AVCaptureVideoDataOutput. My question is then, if I configure my AVCaptureSession differently, or even stop it altogether, is this guaranteed to flush all pending jobs on my background thread? I have a more practical example below, showing how I am accessing something from the foreground thread from the background thread, but I wonder when/how it's safe to clean up that resource. I have setup similar to the following: // Foreground thread logic dispatch_queue_t queue = dispatch_queue_create("avf_camera_queue", nullptr); AVCaptureSession *captureSession = [[AVCaptureSession alloc] init]; setupInputDevice(captureSession); // Connects the AVCaptureDevice... // Store some arbitrary data to be attached to the frame, stored on the foreground thread FrameMetaData frameMetaData = ...; MySampleBufferDelegate *sampleBufferDelegate = [MySampleBufferDelegate alloc]; // Capture frameMetaData by reference in lambda [sampleBufferDelegate setFrameMetaDataGetter: [&frameMetaData]() { return &frameMetaData; }]; AVCaptureVideoDataOutput *captureVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init]; [captureVideoDataOutput setSampleBufferDelegate:sampleBufferDelegate queue:queue]; [captureSession addOutput:captureVideoDataOutput]; [captureSession startRunning]; [captureSession stopRunning]; // Is it now safe to destroy frameMetaData, or do we need manual barrier? And then in MySampleBufferDelegate: - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // Invokes the callback set above FrameMetaData *frameMetaData = frameMetaDataGetter(); emitSampleBuffer(sampleBuffer, frameMetaData); }
Replies
0
Boosts
0
Views
362
Activity
Sep ’25
Why does AVAudioRecorder show 8 kHz when iPhone hardware is 48 kHz?
Hi everyone, I’m testing audio recording on an iPhone 15 Plus using AVFoundation. Here’s a simplified version of my setup: let settings: [String: Any] = [ AVFormatIDKey: Int(kAudioFormatLinearPCM), AVSampleRateKey: 8000, AVNumberOfChannelsKey: 1, AVLinearPCMBitDepthKey: 16, AVLinearPCMIsFloatKey: false ] audioRecorder = try AVAudioRecorder(url: fileURL, settings: settings) audioRecorder?.record() When I check the recorded file’s sample rate, it logs: Actual sample rate: 8000.0 However, when I inspect the hardware sample rate: try session.setCategory(.playAndRecord, mode: .default) try session.setActive(true) print("Hardware sample rate:", session.sampleRate) I consistently get: `Hardware sample rate: 48000.0 My questions are: Is the iPhone mic actually capturing at 8 kHz, or is it recording at 48 kHz and then downsampling to 8 kHz internally? Is there any way to force the hardware to record natively at 8 kHz? If not, what’s the recommended approach for telephony-quality audio (true 8 kHz) on iOS devices? Thanks in advance for your guidance!
Replies
1
Boosts
0
Views
278
Activity
Sep ’25