I'm experiencing audio issues while developing for visionOS when playing PCM data through AVAudioPlayerNode. Issue Description: Occasionally, the speaker produces loud popping sounds or distorted noise This occurs during PCM audio playback using AVAudioPlayerNode The issue is intermittent and doesn't happen every time Technical Details: Platform: visionOS Device: vision pro / simulator Audio Framework: AVFoundation Audio Node: AVAudioPlayerNode Audio Format: PCM I would appreciate any insights on: Common causes of audio distortion with AVAudioPlayerNode Recommended best practices for handling PCM playback in visionOS Potential configuration issues that might cause this behavior Has anyone encountered similar issues or found solutions? Any guidance would be greatly helpful. Thank you in advance!

At present, I am using the avfoundation external device API to connect my iPad to a DSLR camera for data collection. On my end, I am using AVCapture Video Data Output to obtain raw data for processing and rendering. However, the pixelbuf returned from the system layer is incomplete, with only a portion cropped in the middle. But using the Mac API is normal. I would like to ask how to obtain the complete pixelbuf of the image on iPad

Hello, I am trying to read video frames using AVAssetReaderTrackOutput. Here is the sample code: //prepare assets let asset = AVURLAsset(url: some_url) let assetReader = try AVAssetReader(asset: asset) guard let videoTrack = try await asset.loadTracks(withMediaCharacteristic: .visual).first else { throw SomeErrorCode.error } var readerSettings: [String: Any] = [ kCVPixelBufferIOSurfacePropertiesKey as String: [String: String]() ] //check if HDR video var isHDRDetected: Bool = false let hdrTracks = try await asset.loadTracks(withMediaCharacteristic: .containsHDRVideo) if hdrTracks.count > 0 { readerSettings[AVVideoAllowWideColorKey as String] = true readerSettings[kCVPixelBufferPixelFormatTypeKey as String] = kCVPixelFormatType_420YpCbCr10BiPlanarFullRange isHDRDetected = true } //add output to assetReader let output = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: readerSettings) guard assetReader.canAdd(output) else { throw SomeErrorCode.error } assetReader.add(output) guard assetReader.startReading() else { throw SomeErrorCode.error } //add writer ouput settings let videoOutputSettings: [String: Any] = [ AVVideoCodecKey: AVVideoCodecType.hevc, AVVideoWidthKey: 1920, AVVideoHeightKey: 1080, ] let finalPath = "//some URL oath" let assetWriter = try AVAssetWriter(outputURL: finalPath, fileType: AVFileType.mov) guard assetWriter.canApply(outputSettings: videoOutputSettings, forMediaType: AVMediaType.video) else { throw SomeErrorCode.error } let assetWriterInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoOutputSettings) let sourcePixelAttributes: [String: Any] = [ kCVPixelBufferPixelFormatTypeKey as String: isHDRDetected ? kCVPixelFormatType_420YpCbCr10BiPlanarFullRange : kCVPixelFormatType_32ARGB, kCVPixelBufferWidthKey as String: 1920, kCVPixelBufferHeightKey as String: 1080, ] //create assetAdoptor let assetAdaptor = AVAssetWriterInputTaggedPixelBufferGroupAdaptor( assetWriterInput: assetWriterInput, sourcePixelBufferAttributes: sourcePixelAttributes) guard assetWriter.canAdd(assetWriterInput) else { throw SomeErrorCode.error } assetWriter.add(assetWriterInput) guard assetWriter.startWriting() else { throw SomeErrorCode.error } assetWriter.startSession(atSourceTime: CMTime.zero) //prepare tranfer session var session: VTPixelTransferSession? = nil guard VTPixelTransferSessionCreate(allocator: kCFAllocatorDefault, pixelTransferSessionOut: &session) == noErr, let session else { throw SomeErrorCode.error } guard let pixelBufferPool = assetAdaptor.pixelBufferPool else { throw SomeErrorCode.error } //read through frames while let nextSampleBuffer = output.copyNextSampleBuffer() { autoreleasepool { guard let imageBuffer = CMSampleBufferGetImageBuffer(nextSampleBuffer) else { return } //this part copied from (https://developer.apple.com/videos/play/wwdc2023/10181) at 23:58 timestamp let attachment = [ kCVImageBufferYCbCrMatrixKey: kCVImageBufferYCbCrMatrix_ITU_R_2020, kCVImageBufferColorPrimariesKey: kCVImageBufferColorPrimaries_ITU_R_2020, kCVImageBufferTransferFunctionKey: kCVImageBufferTransferFunction_SMPTE_ST_2084_PQ, ] CVBufferSetAttachments(imageBuffer, attachment as CFDictionary, .shouldPropagate) //now convert to CIImage with HDR data let image = CIImage(cvPixelBuffer: imageBuffer) let cropped = "" //here perform some actions like cropping, flipping, etc. and preserve this changes by converting the extent to CGImage first: //this part copied from (https://developer.apple.com/videos/play/wwdc2023/10181) at 24:30 timestamp guard let cgImage = context.createCGImage( cropped, from: cropped.extent, format: .RGBA16, colorSpace: CGColorSpace(name: CGColorSpace.itur_2100_PQ)!) else { continue } //finally convert it back to CIImage let newScaledImage = CIImage(cgImage: cgImage) //now write it to a new pixelBuffer let pixelBufferAttributes: [String: Any] = [ kCVPixelBufferCGImageCompatibilityKey as String: true, kCVPixelBufferCGBitmapContextCompatibilityKey as String: true, ] var pixelBuffer: CVPixelBuffer? CVPixelBufferCreate( kCFAllocatorDefault, Int(newScaledImage.extent.width), Int(newScaledImage.extent.height), kCVPixelFormatType_420YpCbCr10BiPlanarFullRange, pixelBufferAttributes as CFDictionary, &pixelBuffer) guard let pixelBuffer else { continue } context.render(newScaledImage, to: pixelBuffer) //context is a CIContext reference var pixelTransferBuffer: CVPixelBuffer? CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferPool, &pixelTransferBuffer) guard let pixelTransferBuffer else { continue } // Transfer the image to the pixel buffer. guard VTPixelTransferSessionTransferImage(session, from: pixelBuffer, to: pixelTransferBuffer) == noErr else { continue } //finally append to taggedBuffer } } assetWriterInput.markAsFinished() await assetWriter.finishWriting() The result video is not in correct color as the original video. It turns out too bright. If I play around with attachment values, it can be either too dim or too bright but not exactly proper as the original video. What am I missing in my setup? I did find that kCVPixelFormatType_4444AYpCbCr16 can produce proper video output but then I can't convert it to CIImage and so I can't do the CIImage operations that I need. Mainly cropping and resizing the CIImage

Hello! I am building a video camera app and trying to implement Apple log for iPhone 15 Pro and 16 Pro. I am not seeing a lot of documentation on it and notice the amount of apps that use it on the app is rather limited. Less an 5 to be exact. Is Apple Log recording a feature that is accessible to developers? Here is a link to documentation: https://developer.apple.com/documentation/avfoundation/avcapturecolorspace/applelog

Can some one please answer me How Can I update the cookies of the previously set m3u8 video in AVPlayer without creating the new AVURLAsset and replacing the AVPlayer current Item with it

I want to understand the utility of using AsyncStream when iOS 17 introduced @Observable macro where we can directly observe changes in the value of any variable in the model(& observation tracking can happen even outside SwiftUI view). So if I am observing a continuous stream of values, such as download progress of a file using AsyncStream in a SwiftUI view, the same can be observed in the same SwiftUI view using onChange(of:initial) of download progress (stored as a property in model object). I am looking for benefits, drawbacks, & limitations of both approaches. Specifically, my question is with regards to AVCam sample code by Apple where they observe few states as follows. This is done in CameraModel class which is attached to SwiftUI view. // MARK: - Internal state observations // Set up camera's state observations. private func observeState() { Task { // Await new thumbnails that the media library generates when saving a file. for await thumbnail in mediaLibrary.thumbnails.compactMap({ $0 }) { self.thumbnail = thumbnail } } Task { // Await new capture activity values from the capture service. for await activity in await captureService.$captureActivity.values { if activity.willCapture { // Flash the screen to indicate capture is starting. flashScreen() } else { // Forward the activity to the UI. captureActivity = activity } } } Task { // Await updates to the capabilities that the capture service advertises. for await capabilities in await captureService.$captureCapabilities.values { isHDRVideoSupported = capabilities.isHDRSupported cameraState.isVideoHDRSupported = capabilities.isHDRSupported } } Task { // Await updates to a person's interaction with the Camera Control HUD. for await isShowingFullscreenControls in await captureService.$isShowingFullscreenControls.values { withAnimation { // Prefer showing a minimized UI when capture controls enter a fullscreen appearance. prefersMinimizedUI = isShowingFullscreenControls } } } } If we see the structure CaptureCapabilities, it is a small structure with two Bool members. These changes could have been directly observed by a SwiftUI view. I wonder if there is a specific advantage or reason to use AsyncStream here & continuously iterate over changes in a for loop. /// A structure that represents the capture capabilities of `CaptureService` in /// its current configuration. struct CaptureCapabilities { let isLivePhotoCaptureSupported: Bool let isHDRSupported: Bool init(isLivePhotoCaptureSupported: Bool = false, isHDRSupported: Bool = false) { self.isLivePhotoCaptureSupported = isLivePhotoCaptureSupported self.isHDRSupported = isHDRSupported } static let unknown = CaptureCapabilities() }

I’m trying to record videos with AvAssetWriter but sometimes my videos exempt audio buffers recorded and when audio is included, the stream of video buffers stops. the gist below is my code. https://gist.github.com/kwameaj67/70a3409c84d48cf758b3734c08a46244

Hi All, I am working on a DJ playout app (MACOS). The app has a few AVAudioPlayerNode's combined with the ApplicationMusicPlayer from Musickit. I can route the output of the AVaudioPlayer to a hardware device so that the audio files are directed to their own dedicated output on my Mac. The ApplicationMusicPlayer is following the default output and this is pretty annoying. Has anyone found a solution to chain the ApplicationMusicPlayer and get it set to a output device? Thanks Pancras

I noticed that AVSampleBufferDisplayLayerContentLayer is not released when the AVSampleBufferDisplayLayer is removed and released. It is possible to reproduce the issue with the simple code: import AVFoundation import UIKit class ViewController: UIViewController { var displayBufferLayer: AVSampleBufferDisplayLayer? override func viewDidLoad() { super.viewDidLoad() let displayBufferLayer = AVSampleBufferDisplayLayer() displayBufferLayer.videoGravity = .resizeAspectFill displayBufferLayer.frame = view.bounds view.layer.insertSublayer(displayBufferLayer, at: 0) self.displayBufferLayer = displayBufferLayer DispatchQueue.main.asyncAfter(deadline: .now() + 1) { self.displayBufferLayer?.flush() self.displayBufferLayer?.removeFromSuperlayer() self.displayBufferLayer = nil } } } In my real project I have mutliple AVSampleBufferDisplayLayer created and removed in different view controllers, this is problematic because the amount of leaked AVSampleBufferDisplayLayerContentLayer keeps increasing. I wonder that maybe I should use a pool of AVSampleBufferDisplayLayer and reuse them, however I'm slightly afraid that this can also lead to strange bugs. Edit: It doesn't cause leaks on iOS 18 device but leaks on iPad Pro, iOS 17.5.1

Periodically when testing I am running into a situation where the app hangs and beach balls forever when using AVAudioEngine. This seems to log out when this affect happens: Now when this happens if I pause the debugger it's hanging at a call to: [engine connect:playerNode to:engine.mainMixerNode format:buffer.format]; #0 0x000000019391ca9c in __psynch_mutexwait () #1 0x0000000104d49100 in _pthread_mutex_firstfit_lock_wait () #2 0x0000000104d49014 in _pthread_mutex_firstfit_lock_slow () #3 0x00000001938928ec in std::__1::recursive_mutex::lock () #4 0x00000001ef80e988 in CADeprecated::RealtimeMessenger::_PerformPendingMessages () #5 0x00000001ef818868 in AVAudioNodeTap::Uninitialize () #6 0x00000001ef7fdc68 in AUGraphNodeBase::Uninitialize () #7 0x00000001ef884f38 in AVAudioEngineGraph::PerformCommand () #8 0x00000001ef88e780 in AVAudioEngineGraph::_Connect () #9 0x00000001ef8b7e70 in AVAudioEngineImpl::Connect () #10 0x00000001ef8bc05c in -[AVAudioEngine connect:to:format:] () Current all my audio engine related calls are on the main queue (though I am curious about this https://forums.developer.apple.com/forums/thread/123540?answerId=816827022#816827022). In any case, anyone know where I'm going wrong here?

Is there any way to change lens correction on iPad programatically using AVCapture?

Hello, I'm writing a program to create CMAF compliant HLS files, with encryption. I have a copy of ISO_IEC_23001-7_2023 to attempt to follow the spec. I am following the 1:9 pattern encryption using CBCS, so for every 16 bytes of encrypted NAL unit data (of type 1 and 5), there's 144 bytes of clear data. When testing my output in Safari with 'identity' keys Quickly Diagnosing Content Key and IV Issues, Safari will request the identity key from my test server and first few bytes of the CMAF renditions, but will not play and console gives away no clues to the error. I am setting the subsample bytesofclear/protected data in the senc boxes. What I'm not sure of, is whether HLS/Safari/iOS acknowledges the senc/saiz/saio boxes of the MP4. There are other third party packagers Bento4, who suggest that they do not: those clients ignore the explicit encryption layout metadata found in saio/saiz boxes, and instead rely purely on the video slice header size to determine the portions of the sample that is encrypted So now I'm fairly sure I need to decipher the video slice header size, and apply the protected blocks from that point on. My question is, is that all there is to it? And is there a better way to debug my output? mediastreamvalidator will only work against unencrypted variants (which I'm outputting okay). Thanks in advance!

In our app we have implemented a AVAssetResourceLoaderDelegate to handle encrypted downloaded files. We have it working on all iOS versions but we are seeing issues on iOS 15 (15.8.3) with large files (> 1 Gb). We have so far seen two cases where either the load method on the AVURLAsset fails early and throws an unknown error code or starts requesting more data than the device has available RAM. The CPU usage is almost always over 100%, even after pausing playback. The memory issue can happen even though the player has successfully started playback. When running this on devices running iOS 16 and above we set the isEntireLengthAvailableOnDemand to true on the AVAssetResourceLoadingContentInformationRequest. This seems to be key to solving the issue those devices that support it. If we set the property to false we see the same memory issue as on iOS 15. So we have a solution for iOS 16 and upwards but are at a loss for how to handle iOS 15. Is there something we have overlooked or is it in fact an issue with that iOS version?

In an m3u8 manifest, audio EXT-X-MEDIA tags usually contain CHANNELS tag containing the audio channels count like so: #EXT-X-MEDIA:TYPE=AUDIO,URI="audio_clear_eng_stereo.m3u8",GROUP-ID="default-audio-group",LANGUAGE="en",NAME="stream_5",AUTOSELECT=YES,CHANNELS="2" Is it possible to get this info from AVPlayer, AVMediaSelectionOption or some related API?

Hi everyone, I am working on a 3D reconstruction project. Recently I have been able to retrieve the intrinsics from the two cameras on the back of my iPhone. One consideration is that I want this app to run regardless if there is no LiDAR, but at least two cameras on the back. IF there is a LiDAR that is something I have considered to work later on the course of the project. I am using a AVCaptureSession with the two cameras AVCaptureDevice: builtInWideAngleCamera builtInUltraWideCamera The intrinsic matrices seem to be correct. However, the when I retrieve the extrinsics, e.g., builtInWideAngleCamera w.r.t. builtInUltraWideCamera the matrix I get looks like this: Extrinsic Matrix (Ultra-Wide to Wide): [0.9999968, 0.0008149305, -0.0023960583, 0.0] [-0.0008256607, 0.9999896, -0.0044807075, 0.0] [0.002392382, 0.0044826716, 0.99998707, 0.0]. [-14.277955, -8.135408e-10, -0.3359985, 0.0] The extrinsic matrix of the form: [R | t], seems to be correct for the rotational part, but the translational vector is ALL ZEROS. Which suggests that the cameras are physically overlapped as well the last element not being 1 (homogeneous coordinates). Has anyone encountered this 'issue' before? Is there a flaw in my reasoning or something I might be missing? Any comments are very much appreciated.

I've seen the Multiview feature on tvOS that displays a small grid icon when available. However, I only see this functionality in VisionOS using the AVMultiviewManager. Does a different name refer to this feature on tvOS? Relevant Links: https://www.reddit.com/r/appletv/comments/12opy5f/handson_with_the_new_multiview_split_screen/ https://www.pocket-lint.com/how-to-use-multiview-apple-tv/#:~:text=You'll%20see%20a%20grid,running%20at%20the%20same%20time.

I am creating an AVComposition and using it with an AVPlayer. The player works fine and doesn't consume much memory when I do not set playerItem.videoComposition. Here is the code that works without excessive memory usage: func configurePlayer(composition: AVMutableComposition, videoComposition: AVVideoComposition) { player.pause() player.replaceCurrentItem(with: nil) let playerItem = AVPlayerItem(asset: composition) player.play() } However, when I add playerItem.videoComposition = videoComposition, as in the code below, the memory usage becomes excessive: func configurePlayer(composition: AVMutableComposition, videoComposition: AVVideoComposition) { player.pause() player.replaceCurrentItem(with: nil) let playerItem = AVPlayerItem(asset: composition) playerItem.videoComposition = videoComposition player.play() } Issue Details: The memory usage seems to depend on the number of video tracks in the composition, rather than their duration. For instance, two videos of 30 minutes each consume less memory than 40 videos of just 2 seconds each. The excessive memory usage is showing up in the Other Processes section of Xcode's debug panel. For reference, 42 videos, each less than 30 seconds, are using around 1.4 GB of memory. I'm struggling to understand why adding videoComposition causes such high memory consumption, especially since it happens even when no layer instructions are applied. Any insights on how to address this would be greatly appreciated. Before After I initially thought the problem might be due to having too many layer instructions in the video composition, but this doesn't seem to be the case. Even when I set a videoComposition without any layer instructions, the memory consumption remains high.

I tried adding watermarks to the recorded video. Appending sample buffers using AVAssetWriterInput's append method fails and when I inspect the AVAssetWriter's error property, I get the following: Error Domain=AVFoundation Error Domain Code=-11800 "This operation cannot be completed" UserInfo={NSLocalizedFailureReason=An unknown error occurred (-12780), NSLocalizedDDescription=This operation cannot be completed, NSUnderlyingError=0x302399a70 {Error Domain=NSOSStatusErrorDomain Code=-12780 "(null)"}} As far as I can tell -11800 indicates an AVErrorUknown, however I have not been able to find information about the -12780 error code, which as far as I can tell is undocumented. Thanks! Here is the code

Hi, I have a usecase where I'd like to handle and prevent automatic retries whenever certain errors occur during FairPlay content key requests. Here's the current flow: FairPlay certificate is requested and obtained from my server makeStreamingContentKeyRequestData is called on the keyRequest The license server will return a 403 along with a body response containing a json with the detailed code and message The error is caught and handled properly by calling AVContentKeyRequest.processContentKeyResponseError The AVContentKeySession automatically retries up to 8 times by providing a new key request through public func contentKeySession(_ session: AVContentKeySession, didProvide keyRequest: AVContentKeyRequest) My license server gets hit with 8 requests that will always result in a 403, these retries are useless My custom error is succesfully caught later down the line through AVPlayerItem.observe(\.status), this is great Thing is.. I'd like to catch the 403 error and prevent any retry from being made at step 5, ideally through public func contentKeySession(_ session: AVContentKeySession, contentKeyRequest keyRequest: AVContentKeyRequest, didFailWithError err: Error) I've looked for quite a while and just can't seem to find any way of achieving this. Is this not supported at all?

Our iOS/AppleTV video content playback app uses AVPlayer to play HLS video streams and supports both custom and system playback UIs. The Fairplay content key is retrieved using AVContentKeySession. AirPlay is supported too. When the iPhone is connected to a TV through the lightning Apple Digital AV Adapter (A1438), the app is mirrored as expected. Problem: when using an iPhone or iPad on iOS 18.1.1, FairPlay-protected HLS streams are not played and a CoreMediaErrorDomain -12035 error is received by the AVPlayerItem. Also, once the issue has occurred, the mirroring freezes (the TV indefinitely displays the app playback screen) although the app works fine on the iOS device. The content key retrieval works as expected (I can see that 2 content key requests are made by the system by the way, probably one for the local playback and one for the adapter, as when AirPlaying) and the error is thrown after providing the AVContentKeyResponse. Unfortunately, and as far as I know, there is not documentation on CoreMediaErrorDomain errors so I don't know what -12035 means. The issue does not occur: on an iPhone on iOS 17.7 (even with FairPlay-protected HLS streams) when playing DRM-free video content (whatever the iOS version) when using the USB-C AV Adapter (whatever the iOS version) Also worth noting: the issue does not occur with other video playback apps such as Apple TV or Netflix although I don't have any details on the kind of streams these apps play and the way the FairPlay content key is retrieved (if any) so I don't know if it is relevant.