Hi all, I have spent a lot of time reading the tech note and watching the WDDC video that introduce the PTTFramework on iOS. I currently have a custom setup where I am using AVAudioEngine to schedule and play buffers that are being streamed through a call. I am looking to use the PTTFramework to allow a user to trigger this push to talk behavior from the lock screen and the various places with the system UI it provides. However I am unsure what the correct behavior is regarding the handling of the audio session. Right now I am using .playback when there is no active voice transmission so that devices such as AirPods can be in AD2P mode where applicable, and then transitioning to .playbackAndRecord category only when the mic input should become active. Following this change in my AVAudioEngine manager I am then manually activating and deactivating the audio session manually when the engine is either playing/recording or idle. In the documentation it states that you should not attempt to activate or deactivate your audio session directly, but allow the framework to handle it. Does that mean that I need to either call the request to transmit delegate function or set an active participant on the channel manager first, and then wait for the didBecomeActive delegate method to trigger before I actually attempt to play or record any audio? (I am using the fullDuplex mode currently.) I noticed that that delegate method will only trigger if the audio session wasn't active before doing one of the above (setting active participant, requesting transmit). Lastly, when using the PTTFramework it also mentions that we get support for PTT devices and I notice on the didBeginTransmittingFrom property we have a handsfreeButton case. Is there any documentation or resources for what is actually supported out of the box for this? I am currently working on handling a lot of the push to talk through bluetooth LE, and wanted to make sure there wasn't overlap with what the system provides. Thank you!

I've been generating new Audio Unit Extension apps with Xcode 16 (and newer), and although they generally work initially, it is easy (although I'm not sure how to do it reliably) to cause the app to no longer be able to instantiate the audiounit. Generally the call to AVAudioUnit.findComponent fails and SimplePlayEngine hits the fatalError("Failed to find component with type...") In the most recent project, merely adding files to the extension (without making any use of them) caused it to go off the rails. If I "Archive" the app+plugin, there is no audio unit extension in the bundle. If I switch to the audiounit extension and build it it's fine. If I look at the build folder in Library/Developer/Xcode/project_folder the extension_name.appex is there. Any ideas? If I can coax an unmodified audio unit extension project to exhibit this behavior I'll attach it here. Right now what I have has code I don't want to share.

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

We use BassDSDPlayer / SFBAudioEngine to play just about any file, but playing Apple Music is failing. All subscriptions are up to date. We stop the SFBAudioEngine and the BassDSDPlayer before playing Apple Music to no avail. PRINTS: Supported files in /Users/dorian/Music/Music/Media.localized/Music/4: 28364 Apple Music is authorized and can play catalog. Resetting default output device... Releasing BassDSDPlayer audio device... BassDSDPlayer: Audio device released. STOPPED sfbAudioDevice Default output device is ID: 76 applicationQueuePlayer _establishConnectionIfNeeded timeout [ping did not pong] applicationQueuePlayer _establishConnectionIfNeeded timeout [ping did not pong] Player State - After resetting output: Playback Status: stopped Queue Count: 0 No track is playing. Music player reset successfully. BassDSDPlayer: Audio device released. Default output device set successfully: 76 Default output device is ID: 76 Default output device set successfully: 76 Default output device ID: 76 Validated PlayParameters for track: squabble up PlayParameters: PlayParameters(id: 1781270321, kind: "song", isLibrary: nil, catalogID: nil, libraryID: nil, deviceLocalID: nil, rawValues: [:]) Starting playback... Player State - After playback: Playback Status: stopped Queue Count: 1 No track is playing. Notification BASS DSD NSConcreteNotification 0x600007ce2b00 {name = kUpdateSongInfo; object = { AlbumTitle = GNX; ArtistName = "Kendrick Lamar"; SongArtwork = "<NSImage 0x6000041b7ca0 Size={300, 300} RepProvider=<NSImageArrayRepProvider: 0x600003518770, reps:(\n "NSBitmapImageRep 0x600009ed9dc0 Size={300, 300} ColorSpace=(not yet loaded) BPS=8 BPP=(not yet loaded) Pixels=300x300 Alpha=NO Planar=NO Format=(not yet loaded) CurrentBacking=nil (faulting) CGImageSource=0x600007ce15c0"\n)>>"; SongLength = "157.992"; SongTitle = "squabble up"; Source = AppleMusic; }} Apple Music track loaded: squabble up by Kendrick Lamar Player State - Before play: Playback Status: stopped Queue Count: 1 No track is playing. prepareToPlay failed [no target descriptor] NSError Code: 1, Domain: MPMusicPlayerControllerErrorDomain Player State - After play: Playback Status: stopped Queue Count: 1 No track is playing. func playAppleMusicTracks(tracks: [Track]) { AppleMusicManager.shared.isAuthorizedAndReadyForPlayback { isAuthorized in guard isAuthorized else { print("Apple Music authorization or capabilities insufficient for playback.") return } print("Resetting default output device...") self.stopSFBAudioDevice() self.resetMusicPlayer() self.resetAudioSystem() self.ensureOutputDeviceReady() Task { for track in tracks { guard self.validatePlayParameters(for: track) else { continue } do { try await ApplicationMusicPlayer.shared.queue.insert(track, position: .afterCurrentEntry) guard !ApplicationMusicPlayer.shared.queue.entries.isEmpty else { print("Queue is empty after queuing. Playback cannot proceed.") return } self.notifyAppleMusicTrackInfo(track) } catch { print("Error starting playback: \(error)") if let nsError = error as NSError? { print("NSError Code: \(nsError.code), Domain: \(nsError.domain)") } } } MusicKitWrapper.shared.logPlayerState(message: "After playback") } } } @objc public class MusicKitWrapper: NSObject { @objc public static let shared = MusicKitWrapper() private let player = ApplicationMusicPlayer.shared // Play the current track @objc public func play() { guard !player.queue.entries.isEmpty else { print("Queue is empty. Cannot start playback.") return } logPlayerState(message: "Before play") Task { do { try await player.prepareToPlay() try await player.play() print("Playback started successfully.") } catch { if let nsError = error as NSError? { print("NSError Code: \(nsError.code), Domain: \(nsError.domain)") } } logPlayerState(message: "After play") } } Any help would be appreciated. Thanks!

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

I'm working with modern Core Audio API introduced in macOS Sequoia. I have an AudioHadwareDevice which has several controls of type AudioHardwareControl. I figured out to filter only volume controls I can use classID == kAudioVolumeControlClassID condition. Some devices have volume controls for both input and output. How I can determine the direction of the control? Streams, i.e. AudioHardwareStream object have direction, but I didn't found a way to map controls to streams. There are kAudioObjectPropertyScopeInput and kAudioObjectPropertyScopeOutput property scopes, but no matter what I tried controls always return false to any control.hasProperty(address: whatever). Any other ideas?

Hi all, I'm trying to diagnose and resolve an issue with stuttering video playback using the standard AVPlayer. The video in question is a 4K, 39-second file in *.mov format, being played on an iOS device. It's served via a local HTTP server that proxies requests to a backend to fetch and process the content. The project uses end-to-end encrypted storage, which necessitates the proxy for handling data processing. While playback in offline scenarios is smooth, we are encountering issues with smooth playback during streaming. The same video streams smoothly on other platforms using the same connection, so network limitations are not a factor. On iOS, playback is consistently choppy, with pauses every 1-3 seconds. The video does not appear to buffer adequately for smooth playback. One particularly curious aspect is the seemingly random pattern of Content-Range requests made by the AVPlayer when streaming the video. Below is an example of the range requests:

Hello, I am having difficulties with configuring MusicKit correctly for my web app that I am building, seeking assistance with the issues I am having. Would greatly appreciate any help! After allowing access to the following, "Access Request media.mydomain.com would like to access Apple Music, media library, and listening activity for myemail'@icloud.com.", I get a popup error that states, "Authorization failed. Please try again.". Following is the information that is given in developer console: [Error] Failed to load resource: the server responded with a status of 403 () (webPlayerLogout, line 0) [Error] Authorization failed: AUTHORIZATION_ERROR: Unauthorized (anonymous function) (media.mydomain.com:398)

I am trying to get access to raw audio samples from mic. I've written a simple example application that writes the values to a text file. Below is my sample application. All the input samples from the buffers connected to the input tap is zero. What am I doing wrong? I did add the Privacy - Microphone Usage Description key to my application target properties and I am allowing microphone access when the application launches. I do find it strange that I have to provide permission every time even though in Settings > Privacy, my application is listed as one of the applications allowed to access the microphone. class AudioRecorder { private let audioEngine = AVAudioEngine() private var fileHandle: FileHandle? func startRecording() { let inputNode = audioEngine.inputNode let audioFormat: AVAudioFormat #if os(iOS) let hardwareSampleRate = AVAudioSession.sharedInstance().sampleRate audioFormat = AVAudioFormat(standardFormatWithSampleRate: hardwareSampleRate, channels: 1)! #elseif os(macOS) audioFormat = inputNode.inputFormat(forBus: 0) // Use input node's current format #endif setupTextFile() inputNode.installTap(onBus: 0, bufferSize: 1024, format: audioFormat) { [weak self] buffer, _ in self!.processAudioBuffer(buffer: buffer) } do { try audioEngine.start() print("Recording started with format: \(audioFormat)") } catch { print("Failed to start audio engine: \(error.localizedDescription)") } } func stopRecording() { audioEngine.stop() audioEngine.inputNode.removeTap(onBus: 0) print("Recording stopped.") } private func setupTextFile() { let tempDir = FileManager.default.temporaryDirectory let textFileURL = tempDir.appendingPathComponent("audioData.txt") FileManager.default.createFile(atPath: textFileURL.path, contents: nil, attributes: nil) fileHandle = try? FileHandle(forWritingTo: textFileURL) } private func processAudioBuffer(buffer: AVAudioPCMBuffer) { guard let channelData = buffer.floatChannelData else { return } let channelSamples = channelData[0] let frameLength = Int(buffer.frameLength) var textData = "" var allZero = true for i in 0..<frameLength { let sample = channelSamples[i] if sample != 0 { allZero = false } textData += "\(sample)\n" } if allZero { print("Got \(frameLength) worth of audio data on \(buffer.stride) channels. All data is zero.") } else { print("Got \(frameLength) worth of audio data on \(buffer.stride) channels.") } // Write to file if let data = textData.data(using: .utf8) { fileHandle!.write(data) } } }

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

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

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

Hi everyone, I wanted to bring up a question about Core Audio and its potential for future updates or improvements, specifically regarding latency optimization. As someone who relies on Core Audio for real-time audio processing, any enhancements in this area would be incredibly beneficial for professionals in the industry. Does anyone know if Apple has shared any plans or updates regarding Core Audio’s performance, particularly for low-latency applications? I’d appreciate any insights or advice from the community! Thanks so much! Best, Michael

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!

private var audioEngine = AVAudioEngine() private var inputNode: AVAudioInputNode! func startAnalyzing() { inputNode = audioEngine.inputNode let recordingFormat = inputNode.outputFormat(forBus: 0) let hardwareSampleRate = recordingSession.sampleRate inputNode.removeTap(onBus: 0) if recordingFormat.sampleRate != hardwareSampleRate { print("。") let newFormat = AVAudioFormat(commonFormat: recordingFormat.commonFormat, sampleRate: hardwareSampleRate, channels: recordingFormat.channelCount, interleaved: recordingFormat.isInterleaved) inputNode.installTap(onBus: 0, bufferSize: 1024, format: newFormat) { buffer, time in self.processAudioBuffer(buffer, time: time) } } else { inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { buffer, time in self.processAudioBuffer(buffer, time: time) } } do { audioEngine.prepare() try audioEngine.start() } catch { print(": \(error)") } } I back the app to the background and then call startAnalyzing(), which reports an error and the background recording permissions are configured。 error： [10429:570139] [aurioc] AURemoteIO.cpp:1668 AUIOClient_StartIO failed (561145187) [10429:570139] [avae] AVAEInternal.h:109 [AVAudioEngineGraph.mm:1545:Start: (err = PerformCommand(*ioNode, kAUStartIO, NULL, 0)): error 561145187 Audio engine couldn't start. Is background boot not allowed？

I see in most of the old sample codes from Apple that when using AVAssetWriter to append audio, video, and metadata samples in a real time camera recording setup, calls to .append(sampleBuffer) are either synchronised using an NSLock or all the samples are sent to the asset writer on the same dispatch queue thereby preventing concurrent writes. However I can't find any documentation that calls to assetWriterInput.append(sampleBuffer) for different media samples such as Audio and Video should not be done concurrently. Is it not valid for these methods to be executed in parallel for instance? `videoSamplesAssetWriterInput.append(videoSampleBuffer)` from DispatchQueue 1 `audioSamplesAssetWriterInput.append(audioSampleBuffer)` from DispatchQueue 2

Hello, I'm sporadically getting the unknown CoreHaptics error described in the title, when trying to create a CHHapticPatternPlayer from an .ahap file — this does not occur in a repeatable manner, unfortunately... This occurs in a SpriteKit game, running on both iOS 17 and 18. Anyone know what the error means, since it's apparently undocumented? Note that the haptics engine is started right before creating the pattern, and the start request doesn't appear to fail... Thanks, D.

ApplicationMusicPlayer with queue created from playlist crashes with random occurrence shortly after skipping back or forth using controls embedded in the notification, with the error on console log: applicationController: xpc service connection interrupted. I've noticed that the issue occurs more frequently the shorter is time between skipping entries. Since ApplicationMusicPlayer is run on a remote process, the main app does not crash, but the music stops playing without any exception, and the playback control turns uninitiated. Here is how I'm initiating the queue: let entries = playlist .with(.entries).entries! .map { ApplicationMusicPlayer.Queue.Entry($0) } ApplicationMusicPlayer.shared.queue = .init( entries, startingAt: entries.last ) Please give me some tips on how to solve this. EDIT: The issue does not occur when navigating quickly through the station.

I've got a web app built with MusicKit that displays a list of songs. I have player controls for play, pause, skip next, skip, previous, toggle shuffle and set repeat mode. All of these work by using music. The play button, when nothing is playing and nothing is in the queue, will enqueue all the tracks and start playing with the below, for example: await music.setQueue({ songs, startPlaying: true }); I've implemented a progress slider based on feedback from the "playbackProgressDidChange" listener. Now, how in the world can I set the volume? This seems like it should be simple, but I am at a complete loss here. The docs say: "The volume of audio playback, which is set directly on the HTMLMediaElement as the HTMLMediaElement.volume property. This value ranges between 0, which would be muting the audio, and 1, which would be the loudest possible." Given that all my controls work off the music instance, I don't understand how I can do that. In this video from WWDC 2022, music web components are touched on briefly. These are also documented very sparsely. The volume docs are here. For the life of me, I can't even get the volume web component to display in the UI. It appears that MusicKit Web is hobbled compared to the native implementation, but surely adjusting volume shouldn't be that hard right? I'd appreciate any insight on how to do this, including how to get web components to work (in a Next JS app). Thanks.

I set both the AVCapturePhotoOutput and the AVCapturePhotoSettings with maxPhotoDimensions = .init(width: 8064, height: 6048), but still get the 12mp photo.