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); }

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); }

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!

I’m trying to play an Apple Immersive video in the .aivu format using VideoPlayerComponent using the official documentation found here: https://developer.apple.com/documentation/RealityKit/VideoPlayerComponent Here is a simplified version of the code I'm running in another application: import SwiftUI import RealityKit import AVFoundation struct ImmersiveView: View { var body: some View { RealityView { content in let player = AVPlayer(url: Bundle.main.url(forResource: "Apple_Immersive_Video_Beach", withExtension: "aivu")!) let videoEntity = Entity() var videoPlayerComponent = VideoPlayerComponent(avPlayer: player) videoPlayerComponent.desiredImmersiveViewingMode = .full videoPlayerComponent.desiredViewingMode = .stereo player.play() videoEntity.components.set(videoPlayerComponent) content.add(videoEntity) } } } Full code is here: https://github.com/tomkrikorian/AIVU-VideoPlayerComponentIssueSample But the video does not play in my project even though the file is correct (It can be played in Apple Immersive Video Utility) and I’m getting this error when the app crashes: App VideoPlayer+Component Caption: onComponentDidUpdate Media Type is invalid Domain=SpatialAudioServicesErrorDomain Code=2020631397 "xpc error" UserInfo={NSLocalizedDescription=xpc error} CA_UISoundClient.cpp:436 Got error -4 attempting to SetIntendedSpatialAudioExperience [0x101257490|InputElement #0|Initialize] Number of channels = 0 in AudioChannelLayout does not match number of channels = 2 in stream format. Video I’m using is the official sample that can be found here but tried several different files shot from my clients and the same error are displayed so the issue is definitely not the files but on the RealityKit side of things: https://developer.apple.com/documentation/immersivemediasupport/authoring-apple-immersive-video Steps to reproduce the issue: - Open AIVUPlayerSample project and run. Look at the logs. All code can be found in ImmersiveView.swift Sample file is included in the project Expected results: If I followed the documentation and samples provided, I should see my video played in full immersive mode inside my ImmersiveSpace. Am i doing something wrong in the code? I'm basically following the documentation here. Feedback ticket: FB19971306

When changing a camera's exposure, AVFoundation provides a callback which offers the timestamp of the first frame captured with the new exposure duration: AVCaptureDevice.setExposureModeCustom(duration:, iso:, completionHandler:). I want to get a similar callback when changing frame duration. After setting AVCaptureDevice.activeVideoMinFrameDuration or AVCaptureDevice.activeVideoMinFrameDuration to a new value, how can I compute the index or the timestamp of the first camera frame which was captured using the newly set frame duration?

I have a feature requirement: to switch the writer for file writing every 5 minutes, and then quickly merge the last two files. How can I ensure that the merged file is seamlessly combined and that the audio and video information remains synchronized? Currently, the merged video has glitches, and the audio is also out of sync. If there are experts who can provide solutions in this area, I would be extremely grateful.

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

I am trying to get MIDI output from the AU Host demo app using the recent MIDI processor example. The processor works correctly in Logic Pro, but I cannot send MIDI from the AUv3 extension in standalone mode using the default host app to another program (e.g., Ableton). The MIDI manager, which is part of the standalone host app, works fine, and I can send MIDI using it directly—Ableton receives it without issues. I have already set the midiOutputNames in the extension, and the midiOutBlock is mapped. However, the MIDI data from the AUv3 extension does not reach Ableton in standalone mode. I suspect the issue is that midiOutBlock might never be called in the plugin, or perhaps an input to the plugin is missing, which prevents it from sending MIDI. I am currently using the default routing. I have modified the MIDI manager such that it works well as described above. Here is a part of my code for SimplePlayEngine.swift and my MIDIManager.swift for reference: @MainActor @Observable public class SimplePlayEngine { private let midiOutBlock: AUMIDIOutputEventBlock = { sampleTime, cable, length, data in return noErr } var scheduleMIDIEventListBlock: AUMIDIEventListBlock? = nil public init() { engine.attach(player) engine.prepare() setupMIDI() } private func setupMIDI() { if !MIDIManager.shared.setupPort(midiProtocol: MIDIProtocolID._2_0, receiveBlock: { [weak self] eventList, _ in if let scheduleMIDIEventListBlock = self?.scheduleMIDIEventListBlock { _ = scheduleMIDIEventListBlock(AUEventSampleTimeImmediate, 0, eventList) } }) { fatalError("Failed to setup Core MIDI") } } func initComponent(type: String, subType: String, manufacturer: String) async -> ViewController? { reset() guard let component = AVAudioUnit.findComponent(type: type, subType: subType, manufacturer: manufacturer) else { fatalError("Failed to find component with type: \(type), subtype: \(subType), manufacturer: \(manufacturer))" ) } do { let audioUnit = try await AVAudioUnit.instantiate( with: component.audioComponentDescription, options: AudioComponentInstantiationOptions.loadOutOfProcess) self.avAudioUnit = audioUnit self.connect(avAudioUnit: audioUnit) return await audioUnit.loadAudioUnitViewController() } catch { return nil } } private func startPlayingInternal() { guard let avAudioUnit = self.avAudioUnit else { return } setSessionActive(true) if avAudioUnit.wantsAudioInput { scheduleEffectLoop() } let hardwareFormat = engine.outputNode.outputFormat(forBus: 0) engine.connect(engine.mainMixerNode, to: engine.outputNode, format: hardwareFormat) do { try engine.start() } catch { isPlaying = false fatalError("Could not start engine. error: \(error).") } if avAudioUnit.wantsAudioInput { player.play() } isPlaying = true } private func resetAudioLoop() { guard let avAudioUnit = self.avAudioUnit else { return } if avAudioUnit.wantsAudioInput { guard let format = file?.processingFormat else { fatalError("No AVAudioFile defined.") } engine.connect(player, to: engine.mainMixerNode, format: format) } } public func connect(avAudioUnit: AVAudioUnit?, completion: @escaping (() -> Void) = {}) { guard let avAudioUnit = self.avAudioUnit else { return } engine.disconnectNodeInput(engine.mainMixerNode) resetAudioLoop() engine.detach(avAudioUnit) func rewiringComplete() { scheduleMIDIEventListBlock = auAudioUnit.scheduleMIDIEventListBlock if isPlaying { player.play() } completion() } let hardwareFormat = engine.outputNode.outputFormat(forBus: 0) engine.connect(engine.mainMixerNode, to: engine.outputNode, format: hardwareFormat) if isPlaying { player.pause() } let auAudioUnit = avAudioUnit.auAudioUnit if !auAudioUnit.midiOutputNames.isEmpty { auAudioUnit.midiOutputEventBlock = midiOutBlock } engine.attach(avAudioUnit) if avAudioUnit.wantsAudioInput { engine.disconnectNodeInput(engine.mainMixerNode) if let format = file?.processingFormat { engine.connect(player, to: avAudioUnit, format: format) engine.connect(avAudioUnit, to: engine.mainMixerNode, format: format) } } else { let stereoFormat = AVAudioFormat(standardFormatWithSampleRate: hardwareFormat.sampleRate, channels: 2) engine.connect(avAudioUnit, to: engine.mainMixerNode, format: stereoFormat) } rewiringComplete() } } and my MIDI Manager @MainActor class MIDIManager: Identifiable, ObservableObject { func setupPort(midiProtocol: MIDIProtocolID, receiveBlock: @escaping @Sendable MIDIReceiveBlock) -> Bool { guard setupClient() else { return false } if MIDIInputPortCreateWithProtocol(client, portName, midiProtocol, &port, receiveBlock) != noErr { return false } for source in self.sources { if MIDIPortConnectSource(port, source, nil) != noErr { print("Failed to connect to source \(source)") return false } } setupVirtualMIDIOutput() return true } private func setupVirtualMIDIOutput() { let virtualStatus = MIDISourceCreate(client, virtualSourceName, &virtualSource) if virtualStatus != noErr { print("❌ Failed to create virtual MIDI source: \(virtualStatus)") } else { print("✅ Created virtual MIDI source: \(virtualSourceName)") } } func sendMIDIData(_ data: [UInt8]) { print("hey") var packetList = MIDIPacketList() withUnsafeMutablePointer(to: &packetList) { ptr in let pkt = MIDIPacketListInit(ptr) _ = MIDIPacketListAdd(ptr, 1024, pkt, 0, data.count, data) if virtualSource != 0 { let status = MIDIReceived(virtualSource, ptr) if status != noErr { print("❌ Failed to send MIDI data: \(status)") } else { print("✅ Sent MIDI data: \(data)") } } } } }

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.

When I try to send a DRM-protected video via Airplay to an Apple TV, the license request is made twice instead of once as it normally does on iOS. We only allow one request per session for security reasons, this causes the second request to fail and the video won't play. We've tested DRM-protected videos without token usage limits and it works, but this creates a security hole in our system. Why does it request the license twice in function: func contentKeySession(_ session: AVContentKeySession, didProvide keyRequest: AVContentKeyRequest)? Is there a way to prevent this?

AVAudioSessionCategoryOptionAllowBluetooth is marked as deprecated in iOS 8 in iOS 26 beta 5 when this option was not deprecated in iOS 18.6. I think this is a mistake and the deprecation is in iOS 26. Am I right? It seems that the substitute for this option is "AVAudioSessionCategoryOptionAllowBluetoothHFP". The documentation does not make clear if the behaviour is exactly the same or if any difference should be expected... Has anyone used this option in iOS 26? Should I expect any difference with the current behaviour of "AVAudioSessionCategoryOptionAllowBluetooth"? Thank you.

In my app I use AVAssetReaderTrackOutput to extract PCM audio from a user-provided video or audio file and display it as a waveform. Recently a user reported that the waveform is not in sync with his video, and after receiving the video I noticed that the waveform is in fact double as long as the video duration, i.e. it shows the audio in slow-motion, so to speak. Until now I was using CMFormatDescription.audioStreamBasicDescription.mSampleRate which for this particular user video returns 22'050. But in this case it seems that this value is wrong... because the audio file has two audio channels with different sample rates, as returned by CMFormatDescription.audioFormatList.map({ $0.mASBD.mSampleRate }) The first channel has a sample rate of 44'100, the second one 22'050. If I use the first sample rate, the waveform is perfectly in sync with the video. The problem is given by the fact that the ratio between the audio data length and the sample rate multiplied by the audio duration is 8, double the ratio for the first audio file (4). In the code below this ratio is given by Double(length) / (sampleRate * asset.duration.seconds) When commenting out the line with the sampleRate variable definition in the code below and uncommenting the following line, the ratios for both audio files are 4, which is the expected result. I would expect audioStreamBasicDescription to return the correct sample rate, i.e. the one used by AVAssetReaderTrackOutput, which (I think) somehow merges the stereo tracks. The documentation is sparse, and in particular it’s not documented whether the lower or higher sample rate is used; in this case, it seems like the higher one is used, but audioStreamBasicDescription for some reason returns the lower one. Does anybody know why this is the case or how I should extract the sample rate of the produced PCM audio data? Should I always take the higher one? I created FB19620455. let openPanel = NSOpenPanel() openPanel.allowedContentTypes = [.audiovisualContent] openPanel.runModal() let url = openPanel.urls[0] let asset = AVURLAsset(url: url) let assetTrack = asset.tracks(withMediaType: .audio)[0] let assetReader = try! AVAssetReader(asset: asset) let readerOutput = AVAssetReaderTrackOutput(track: assetTrack, outputSettings: [AVFormatIDKey: Int(kAudioFormatLinearPCM), AVLinearPCMBitDepthKey: 16, AVLinearPCMIsBigEndianKey: false, AVLinearPCMIsFloatKey: false, AVLinearPCMIsNonInterleaved: false]) readerOutput.alwaysCopiesSampleData = false assetReader.add(readerOutput) let formatDescriptions = assetTrack.formatDescriptions as! [CMFormatDescription] let sampleRate = formatDescriptions[0].audioStreamBasicDescription!.mSampleRate //let sampleRate = formatDescriptions[0].audioFormatList.map({ $0.mASBD.mSampleRate }).max()! print(formatDescriptions[0].audioStreamBasicDescription!.mSampleRate) print(formatDescriptions[0].audioFormatList.map({ $0.mASBD.mSampleRate })) if !assetReader.startReading() { preconditionFailure() } var length = 0 while assetReader.status == .reading { guard let sampleBuffer = readerOutput.copyNextSampleBuffer(), let blockBuffer = sampleBuffer.dataBuffer else { break } length += blockBuffer.dataLength } print(Double(length) / (sampleRate * asset.duration.seconds))

I'm working on a video player app that has the basic functionality of viewing a video and then be able to trim and crop that video and then save it. My flow of trimming a video and then saving it works well with any and every video. Cropping, however, doesn't work in the sense that I am unable to Save the video and export it. Whenever I crop a video, in the video player, I can see the cropped version of the video (it plays too!) but on saving said video, I get the error: Export failed with status: 4, error: Cannot Decode I've been debugging for 2 days now but I'm still unsure as to why this happens. I'm almost certain the bug is somewhere cause of cropping and then saving/exporting. If anyone has dealt with this before, please let me know what the best step to do is! If you could help me refine the flow for cropping and exporting, that'd be really helpful too. Thanks!

I want to build an app for ios using react native. preferably expo. The app will be for recording user experiences with technology. the SLUDGE that they face while navigating through technology. I want to have basic login, signup. The main feature would be to have 2 recording modes. First is record the screen and the front camera simultaneously. Second is to record the back camera and the front camera simultaneously. I can then patch the two outputs later on that is the screen recording and the front camera clip in post processing. I want to know if this is possible as I was told that react native and expo does not have the support yet. if not is there any library or another approach to make this app come alive.

I am developing an app that plays HLS audio. When using AVPlayerItem with AVURLAsset, can AVAssetResourceLoaderDelegate correctly handle HLS segments? My goal is to use AVAssetResourceLoaderDelegate to add authentication HTTP headers when accessing HLS .m3u8 and .ts files. I can successfully download the files, but playback fails with errors. Specifically, I am observing the following cases: A. AVAssetResourceLoaderDelegate is canceled, and CoreMediaErrorDomain -12881 occurs In NSURLConnectionDataDelegate’s didReceiveResponse method, set contentInformationRequest In didReceiveData, call dataRequest respondWithData resourceLoader didCancelLoadingRequest is called CoreMediaErrorDomain -12881 occurs B. CoreMediaErrorDomain -12881 occurs In NSURLConnectionDataDelegate’s didReceiveResponse method, set contentInformationRequest In connection didReceiveData, buffer all received data until the end In connectionDidFinishLoading, pass the buffered data to respondWithData Call loadingRequest finishLoading CoreMediaErrorDomain -12881 occurs In both cases, dataRequest.requestsAllDataToEndOfResource is YES. For this use case, I am not using AVURLAssetHTTPHeaderFieldsKey because I need to apply the most up-to-date authentication data at the moment each file is accessed. I would appreciate any advice or suggestions you might have. Thank you in advance!

After updating to iOS 18.5, we’ve observed that outgoing audio from our app intermittently stops being transmitted during VoIP calls using AVAudioSession configured with .playAndRecord and .voiceChat. The session is set active without errors, and interruptions are handled correctly, yet audio capture suddenly ceases mid-call. This was not observed in earlier iOS versions (≤ 18.4). We’d like to confirm if there have been any recent changes in AVAudioSession, CallKit, or related media handling that could affect audio input behavior during long-running calls. func configureForVoIPCall() throws { try setCategory( .playAndRecord, mode: .voiceChat, options: [.allowBluetooth, .allowBluetoothA2DP, .defaultToSpeaker]) try setActive(true) }

Since iOS 18, the system setting “Allow Audio Playback” (enabled by default) allows third-party app audio to continue playing while the user is recording video with the Camera app. This has created a problem for the app I’m developing. ➡️ The problem: My app plays continuous audio in both foreground and background states. If the user starts recording video using the iOS Camera app, the app’s audio — still playing in the background — gets captured in the video — obviously an unintended behavior. Yes, the user could stop the app manually before starting the video recording, but that can’t be guaranteed. As a developer, I need a way to stop the app’s audio before the video recording begins. So far, I haven’t found a reliable way to detect when video recording starts if ‘Allow Audio Playback’ is ON. ➡️ What I’ve tried: — AVAudioSession.interruptionNotification → doesn’t fire — devicesChangedEventStream → not triggered I don’t want to request mic permission (app doesn’t use mic). also, disabling the app from playing audio in the background isn’t an option as it is a crucial part of the user experience ➡️ What I need: A reliable, supported way to detect when the Camera app begins video recording, without requiring mic access — so I can stop audio and avoid unintentional overlap with the user’s recordings. Any official guidance, workarounds, or AVFoundation techniques would be greatly appreciated. Thanks.

When using AVSampleBufferDisplayLayer to play uncompressed H.264 and H.265 video with B-frames more than 7, frame drops occur. The more B-frames there are, the more noticeable the frame drops become, for example 15 bframes. Use FFmpeg to transcode a video file with visible timestamps and frame numbers (x264 or x265 ): ffmpeg -i test.mp4 -vf "drawtext=fontsize=45:text=%{pts} %{n}:y=400" -c:v libx264 -x264-params "bframes=15:b-adapt=0" -crf 30 -y x264_bf15.mp4 ffmpeg -i test.mp4 -vf "drawtext=fontsize=45:text=%{pts} %{n}:y=400" -c:v libx265 -x265-params "bframes=15:b-adapt=0" -crf 30 -y x265_bf15.mp4 Use the demo player from this repository to reproduce the issue: https://github.com/msfrms/CustomPlayer frame drops can be observed. And following log can be found in devices console. mediaserverd <<<< IQ-CA >>>> piqca_gmstats_dump: FIQCA(0x1266f4000) recent frames: enqueued: 184, displayed: 138, dropped: 42, flushed: 0, evicted: 3, >16ms late: 2 PS. I was using iphone11 iOS14.6, to replay this issue. May I ask why frame drops occur in this case? Is there any configuration or API usage change that could help fix the frame drop issue? Many thanks!

Recurring crash on install of any app with the new sourceVideoTrackProvider.next() dyld[41966]: Symbol not found: _$sSo19AVAssetReaderOutputC12AVFoundationE8ProviderC4nextxSgyYaKFTjTu Referenced from: <79AA2BE0-A6B4-32F5-A804-E84BBE5D1AEA> /Users/<username>/Library/Developer/Xcode/DerivedData/TrackProviderCrash-bbbhjptcxnmfdcackxtpucnunxyc/Build/Products/Debug-maccatalyst/TrackProviderCrash.app/Contents/MacOS/TrackProviderCrash.debug.dylib Expected in: <1B847AF9-7973-3B28-95C2-09E73F6DD50B> /usr/lib/swift/libswiftAVFoundation.dylib Can be reproduced with the current Xcode Beta 4 by running on to MacCatalyst and macOS https://developer.apple.com/documentation/AVFoundation/converting-projected-video-to-apple-projected-media-profile Crash goes away of you comment out lines 154-158 and 164-170 which are while let sampleBuffer = try await sourceVideoTrackProvider.next(){/*other code*/} Can also be reproduced if you add the code below to a MacCatalyst project import AVKit let asset: AVURLAsset = .init(url: Bundle.main.url(forResource: "SomeVideo.mp4", withExtension: nil)!) let videoReader = try! AVAssetReader(asset: asset) let videoTracks = try! await asset.loadTracks(withMediaCharacteristic: .visual) // Get the side-by-side video track. let videoTrack = videoTracks.first! let videoInputTrack = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: nil) let sourceVideoTrackProvider: AVAssetReaderOutput.Provider<CMReadySampleBuffer<CMSampleBuffer.DynamicContent>> = videoReader.outputProvider(for: videoInputTrack) //Comment out this while let sb = try! await sourceVideoTrackProvider.next() { }

i'm trying to work on a simple screen recording app on macOS that always records the last 'x' seconds of your screen and saves it whenever you want, as a way to get comfortable with swift programming and apple APIs. i was able to get it running for the past '30 seconds' and record and store it. however i realised that there was a core issue with my solution: i was defining the SCStreamConfiguration.queueDepth = 900 (to account for 30fps for 30 seconds) which goes completely against apple's instructions: https://developer.apple.com/documentation/screencapturekit/scstreamconfiguration/queuedepth?language=objc now when i changed queueDepth back to 8, i am only able to record 8 frames and it saves only those first 8 frames. i am unsure what the flow of the apis should be while dealing with screenCaptureKit. for context, here's my recording manager code that handles this logic (queueDepth = 900) import Foundation import ScreenCaptureKit import AVFoundation class RecordingManager: NSObject, ObservableObject, SCStreamDelegate { static let shared = RecordingManager() @Published var isRecording = false private var isStreamActive = false // Custom state flag private var stream: SCStream? private var streamOutputQueue = DispatchQueue(label: "com.clipback.StreamOutput", qos: .userInteractive) private var screenStreamOutput: ScreenStreamOutput? // Strong reference to output private var lastDisplayID: CGDirectDisplayID? private let displayCheckQueue = DispatchQueue(label: "com.clipback.DisplayCheck", qos: .background) // In-memory rolling buffer for last 30 seconds private var rollingFrameBuffer: [(CMSampleBuffer, CMTime)] = [] private let rollingFrameBufferQueue = DispatchQueue(label: "com.clipback.RollingBuffer", qos: .userInteractive) private let rollingBufferDuration: TimeInterval = 30.0 // seconds // Track frame statistics private var frameCount: Int = 0 private var lastReportTime: Date = Date() // Monitor for display availability private var displayCheckTimer: Timer? private var isWaitingForDisplay = false func startRecording() { print("[DEBUG] startRecording called.") guard !isRecording && !isWaitingForDisplay else { print("[DEBUG] Already recording or waiting, ignoring startRecording call") return } isWaitingForDisplay = true isStreamActive = true // Set active state checkForDisplay() } private func setupAndStartRecording(for display: SCDisplay, excluding appToExclude: SCRunningApplication?) { print("[DEBUG] setupAndStartRecording called for display: \(display.displayID)") let excludedApps = [appToExclude].compactMap { $0 } let filter = SCContentFilter(display: display, excludingApplications: excludedApps, exceptingWindows: []) let config = SCStreamConfiguration() config.width = display.width config.height = display.height config.minimumFrameInterval = CMTime(value: 1, timescale: 30) // 30 FPS config.queueDepth = 900 config.showsCursor = true print("[DEBUG] SCStreamConfiguration created: width=\(config.width), height=\(config.height), FPS=\(config.minimumFrameInterval.timescale)") stream = SCStream(filter: filter, configuration: config, delegate: self) print("[DEBUG] SCStream initialized.") self.screenStreamOutput = ScreenStreamOutput { [weak self] sampleBuffer, outputType in guard let self = self else { return } guard outputType == .screen else { return } guard sampleBuffer.isValid else { return } guard let attachments = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, createIfNecessary: false) as? [[SCStreamFrameInfo: Any]], let statusRawValue = attachments.first?[.status] as? Int, let status = SCFrameStatus(rawValue: statusRawValue), status == .complete else { return } self.trackFrameRate() self.handleFrame(sampleBuffer) } do { try stream?.addStreamOutput(screenStreamOutput!, type: .screen, sampleHandlerQueue: streamOutputQueue) stream?.startCapture { [weak self] error in print("[DEBUG] SCStream.startCapture completion handler.") guard error == nil else { print("[DEBUG] Failed to start capture: \(error!.localizedDescription)") self?.handleStreamError(error!) return } DispatchQueue.main.async { self?.isRecording = true self?.isStreamActive = true // Update state on successful start print("[DEBUG] Recording started. isRecording = true.") } } } catch { print("[DEBUG] Error adding stream output: \(error.localizedDescription)") handleStreamError(error) } } private func handleFrame(_ sampleBuffer: CMSampleBuffer) { rollingFrameBufferQueue.async { [weak self] in guard let self = self else { return } let pts = CMSampleBufferGetPresentationTimeStamp(sampleBuffer) var retainedBuffer: CMSampleBuffer? CMSampleBufferCreateCopy(allocator: kCFAllocatorDefault, sampleBuffer: sampleBuffer, sampleBufferOut: &retainedBuffer) guard let buffer = retainedBuffer else { print("[DEBUG] Failed to copy sample buffer") return } self.rollingFrameBuffer.append((buffer, pts)) if let lastPTS = self.rollingFrameBuffer.last?.1 { while let firstPTS = self.rollingFrameBuffer.first?.1, CMTimeGetSeconds(CMTimeSubtract(lastPTS, firstPTS)) > self.rollingBufferDuration { self.rollingFrameBuffer.removeFirst() } } } } func stream(_ stream: SCStream, didStopWithError error: Error) { print("[DEBUG] Stream stopped with error: \(error.localizedDescription)") displayCheckQueue.async { [weak self] in // Move to displayCheckQueue for synchronization self?.handleStreamError(error) } } what could be the reason for this and what would be the possible fix logically? i dont understand why it's dependant on queueDepth, and if it is, how can I empty and append new recorded frames to it so that it continues working? any help or resource is greatly appreciated!