My current app implements a custom video player, based on a AVSampleBufferRenderSynchronizer synchronising two renderers: an AVSampleBufferDisplayLayer receiving decoded CVPixelBuffer-based video CMSampleBuffers, and an AVSampleBufferAudioRenderer receiving decoded lpcm-based audio CMSampleBuffers. The AVSampleBufferRenderSynchronizer is started when the first image (in presentation order) is decoded and enqueued, using avSynchronizer.setRate(_ rate: Float, time: CMTime), with rate = 1 and time the presentation timestamp of the first decoded image. Presentation timestamps of video and audio sample buffers are consistent, and on most streams, the audio and video are correctly synchronized. However on some network streams, on iOS, the audio and video aren't synchronized, with a time difference that seems to increase with time. On the other hand, with the same player code and network streams on macOS, the synchronization always works fine. This reminds me of something I've read, about cases where an AVSampleBufferRenderSynchronizer could not synchronize audio and video, causing them to run with independent and potentially drifting clocks, but I cannot find it again. So, any help / hints on this sync problem will be greatly appreciated! :)

I'm getting Crashlytics crashes from some my users, deep in the Apple code: Crashed: AXSpeech EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x00000007ec54b360 0 libobjc.A.dylib 0x3c9c objc_retain_x8 + 16 1 AudioToolboxCore 0x99580 auoop::RenderPipeUser::~RenderPipeUser() + 112 2 AudioToolboxCore 0xe6090 -[AUAudioUnit_XPC internalDeallocateRenderResources] + 92 3 AVFAudio 0x90a0 AUInterfaceBaseV3::Uninitialize() + 60 4 AVFAudio 0x4cbe0 AVAudioEngineGraph::PerformCommand(AUGraphNodeBaseV3&, AVAudioEngineGraph::ENodeCommand, void*, unsigned int) const + 768 5 AVFAudio 0x56b0c AVAudioEngineGraph::_Uninitialize(NSError**) + 132 6 AVFAudio 0x7834 AVAudioEngineImpl::Stop(NSError**) + 388 7 AVFAudio 0x636c -[AVAudioEngine dealloc] + 52 8 TextToSpeech 0x30674 _TTSNameForVoiceInformation + 20864 9 libobjc.A.dylib 0x20a4 object_cxxDestructFromClass(objc_object*, objc_class*) + 116 10 libobjc.A.dylib 0x6e00 objc_destructInstance + 80 11 libobjc.A.dylib 0x104fc _objc_rootDealloc + 80 12 TextToSpeech 0x2d2f4 _TTSNameForVoiceInformation + 7680 13 TextToSpeech 0x496c TTSVocalizerCopyURLForFallbackResource + 8540 14 TextToSpeech 0x26094 TTSSpeechUnitTestingMode + 5548 15 libAXSpeechManager.dylib 0x108b0 -[AXSpeechManager .cxx_destruct] + 192 16 libobjc.A.dylib 0x20a4 object_cxxDestructFromClass(objc_object*, objc_class*) + 116 17 libobjc.A.dylib 0x6e00 objc_destructInstance + 80 18 libobjc.A.dylib 0x104fc _objc_rootDealloc + 80 19 libAXSpeechManager.dylib 0x5298 -[AXSpeechManager dealloc] + 268 20 Foundation 0x3b8a4 __NSThreadPerformPerform + 272 21 CoreFoundation 0xd3208 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 22 CoreFoundation 0xdf864 __CFRunLoopDoSource0 + 176 23 CoreFoundation 0x646c8 __CFRunLoopDoSources0 + 244 24 CoreFoundation 0x7a1c4 __CFRunLoopRun + 828 25 CoreFoundation 0x7f4dc CFRunLoopRunSpecific + 612 26 Foundation 0x420c4 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 212 27 libAXSpeechManager.dylib 0x13390 -[AXSpeechThread main] + 552 28 Foundation 0x5b634 __NSThread__start__ + 716 29 libsystem_pthread.dylib 0x16b8 _pthread_start + 148 30 libsystem_pthread.dylib 0xb88 thread_start + 8 It's most likely related to my use of AVSpeechSynthesizer. I do change some of the utterance fields, including the voice that's being used (which is set to a value from speechVoices()). UtilAudioIos_tts = AVSpeechSynthesizer() let utterance = AVSpeechUtterance utterance.voice = AVSpeechSynthesisVoice(identifier: voice.voiceCode) utterance.volume = volume utterance.pitchMultiplier = pitch utterance.rate = rate UtilAudioIos_tts!.speak(utterance) By coincidence or not, the following sometimes appears in the device log: 2023-05-30 20:35:29.948078+0100 <appname>[466:12882] [catalog] Unable to list voice folder and also, sometimes: 2023-05-30 20:37:35.345933+0100 <appname>[466:13298] [catalog] Query for com.apple.MobileAsset.VoiceServices.VoiceResources failed: 2 2023-05-30 20:37:35.360854+0100 rehearserfree[466:13433] [AXTTSCommon] MauiVocalizer: 11006 (Can't compile rule): regularExpression=\Oviedo(?=, (\x1b\\pause=\d+\\)?Florida)\b, message=unrecognized character follows \, characterPosition=1 2023-05-30 20:37:35.363163+0100 <appname>[466:13433] [AXTTSCommon] MauiVocalizer: 16038 (Resource load failed): component=ttt/re, uri=, contentType=application/x-vocalizer-rettt+text, lhError=88602000 2023-05-30 20:37:35.363182+0100 <appname>[466:13433] [AXTTSCommon] Error loading rules: 2147483648 All of these crashes have been on the various versions of iOS 16. Edit: I can't reproduce the crash myself - it's just some (not all) app users. The log entries above appear locally on my device (with no crash) but I can't see the logs of the users who have the crashes. Any idea what this might be caused by, or how to go about tracking the problem down?

I want the audio session to always use the built-in microphone. However, when using the setPreferredInput() method like in this example private func enableBuiltInMic() { // Get the shared audio session. let session = AVAudioSession.sharedInstance() // Find the built-in microphone input. guard let availableInputs = session.availableInputs, let builtInMicInput = availableInputs.first(where: { $0.portType == .builtInMic }) else { print("The device must have a built-in microphone.") return } // Make the built-in microphone input the preferred input. do { try session.setPreferredInput(builtInMicInput) } catch { print("Unable to set the built-in mic as the preferred input.") } } and calling that function once in the initializer, the audio session still switches to the external microphone once one is plugged in. The session's preferredInput is nil again at that point, even if the built-in microphone is still listed in availableInputs. So, why is the preferredInput suddenly reset? when would be the appropriate time to set the preferredInput again? Observing the session’s availableInputs did not work and setting the preferredInput again in the routeChangeNotification handler seems a bad choice as it’s already a bit too late then.

Dear Sirs, I'd like to add an icon to my audio driver based on AudioDriverKit. This icon should show up left of my audio device in the audio devices dialog. For an Audio Server Plugin I managed to do this using the property kAudioDevicePropertyIcon and CFBundleCopyResourceURL(...) but how would you do this with AudioDriverKit? Should I use IOUserAudioCustomProperty or IOUserAudioControl and how would I refer to the Bundle? Is there an example available somewhere? Thanks and best regards, Johannes

I'm developing iPad app that will be mostly dedicated for certain external camera for visually impaired people. The linux UVC api (e.g. using guvcview) allows to enable automatic exposure for the camera. IOs api "isExposureModeSupported" unfortunately returns false for any of the exposure modes. Is it a bug? Or perhaps AVFoundation doesn't support UVC exposure yet?

Hi, I am creating an app that can include videos or images in it's data. While @Attribute(.externalStorage) helps with images, with AVAssets I actually would like access to the URL behind that data. (as it would be stupid to load and then save the data again just to have a URL) One key component is to keep all of this clean enough so that I can use (private) CloudKit syncing with the resulting model. All the best Christoph

Hi everyone, I'm the owner of a radio station called Radio Krimi and we have an official APP on iOS but because the technician, don't replied anymore to our message, we would like to update it with a new audio link. Then deeply sorry but I really don't know how to do it, basically it sould be easy because is a just a new link instead an old one. Please someone could help us with the process ? Thanks a lot ! Seb https://apps.apple.com/fr/app/radio-krimi/id1034088733

So I've spent the last five years optimizing my video AI system so that it runs with less than 5% CPU while processing a 30fps video feed on a Macbook Pro M2, and everything is great, until Sonoma comes out, and I find myself consuming 40% CPU for the exact same workload. So I fire up Instruments, and the "heaviest stack trace" (see screenshot) turns out to be Espresso doing some completely unasked-for and absolutely useless processing on my video frames. I turn off Reactions, but nothing helps - the CPU consumptions stays at 40%. "Reactions" is nothing but a useless toy to please some WWDC keynote fanboys, I don't want it anywhere near my app or my users, and I especially do not want to take the blame for it pissing away the user's CPU cycles and battery. Now, how do I make it go away, for ever? Best regards Jacob

Hello, Starting in iOS 17, our application started having some issue publishing to our video session. More specifically the video capture seems to be broken in some, but not all sessions. What's troubling is that we're seeing that it fails consistently every 4 sessions. It also fails silently, without reporting any problems to the app. We only notice that there are no frames being rendered or sent to the remote devices. Here's what shows-up in the console: <<<< FigCaptureSourceRemote >>>> Fig assert: "! storage->connectionDied" at bail (FigCaptureSourceRemote.m:235) - (err=0) <<<< FigCaptureSourceRemote >>>> Fig assert: "err == 0 " at bail (FigCaptureSourceRemote.m:253) - (err=-16453) Anyone seeing this? Any idea what could be the cause? Our sessions work perfectly on iOS16 and below. Thanks

My app uses the AVFoundation to pronounce some words. Running the app from Xcode, either to a simulator or device, I frequently get this crash at start-up: AXSpeech (13): EXC_BAD_ACCESS (code=EXC_I386_GPFLT). It seems to occur randomly, maybe 20%-30% of the time I launch the app. When it does not crash, using audio works as expected. When launched from the device, it never crashes (so far, at least). Here's the code that outputs speech: Declared at the top level of the View struct: @State var synth = AVSpeechSynthesizer() In the View, as part of a Button's action closure: let utterance = AVSpeechUtterance(string: answer) utterance.voice = AVSpeechSynthesisVoice(language: "en_US") synth.speak(utterance) Any idea on how to stop this? It's annoying having to launch the app multiple times to test on a simulator or device.

I have a PCM audio buffer (AVAudioPCMFormatInt16). When I try to play it using AVPlayerNode / AVAudioEngine an exception is thrown: "[[busArray objectAtIndexedSubscript:(NSUInteger)element] setFormat:format error:&nsErr]: returned false, error Error Domain=NSOSStatusErrorDomain Code=-10868 (related thread https://forums.aninterestingwebsite.com/forums/thread/700497?answerId=780530022#780530022) If I convert the buffer to AVAudioPCMFormatFloat32 playback works. My questions are: Does AVAudioEngine / AVPlayerNode require AVAudioPCMBuffer to be in the Float32 format? Is there a way I can configure it to accept another format instead for my application? If 1 is YES is this documented anywhere? If 1 is YES is this required format subject to change at any point? Thanks! I was looking to watch the "AVAudioEngine in Practice" session video from WWDC 2014 but I can't find it anywhere (https://forums.aninterestingwebsite.com/forums/thread/747008).

Hi, I'm new to AVAudioEngine(and macOS programming in general). I'm trying to mix microphone audio with ScreenCaptureKit audio using AVAudioEngine without playing it back. I've created a AVAudioPlayerNode and scheduling buffers in my SCStream handler: playerNode.scheduleBuffer(samples) and have connected the playerNode to the mainMixerNode. audioEngine.connect(audioEngine.inputNode, to: audioEngine.mainMixerNode, format: micFormat) audioEngine.connect(playerNode, to: audioEngine.mainMixerNode, format: format) The problem is that mainMixerNode plays the audio to the speaker creating a feedback loop. How can I prevent the mixer output from being played back. Also: Is this the best way of mixing microphone input with some other input? I ran into AVAudioEngine's manual rendering mode, which seems like the way to go for mixing audio without playing it back. However, I couldn't figure out how to connect microphone input to the AVAudioEngine in manual rendering mode?

Is it possible to find IDR frame (CMSampleBuffer) in AVAsset h264 video file?

Hi, I am getting into a trap. Please check stack-trace, howto fix this? regards, Joël stack-trace with ExtAudioFileWrite

Is there any feasible way to get a Core Audio device's system effect status (Voice Isolation, Wide Spectrum)? AVCaptureDevice provides convenience properties for system effects for video devices. I need to get this status for Core Audio input devices.

The same H265 encrypted Fairplay content can be played in all Apple devices except A1625. The clear H265 content is played in A1625. The question is: will this model (A1625) support H265 Fairplay encrypted content? A ticket was created here: https://discussions.apple.com/thread/255658006?sortBy=best

AVAudioFormat has no Swift concurrency annotations but the documentation states "Instances of this class are immutable." This made me always assume it was safe to pass AVAudioFormat instances around. Is this the case? If so can it be marked as Sendable? Am I missing something?

I've been using CGWindowListCreateImage which automatically creates an image with the size of the captured window. But SCScreenshotManager.captureImage(contentFilter:configuration:) always creates images with the width and height specified in the provided SCStreamConfiguration. I could be setting the size explicitly by reading SCWindow.frame or SCContentFilter.contentRect and multiplying the width and height by SCContentFilter.pointPixelScale , but it won't work if I want to keep the window shadow with SCStreamConfiguration.ignoreShadowsSingleWindow = false. Is there a way and what's the best way to take full-resolution screenshots of the correct size? import Cocoa import ScreenCaptureKit class ViewController: NSViewController { @IBOutlet weak var imageView: NSImageView! override func viewDidAppear() { imageView.imageScaling = .scaleProportionallyUpOrDown view.wantsLayer = true view.layer!.backgroundColor = .init(red: 1, green: 0, blue: 0, alpha: 1) Task { let windows = try await SCShareableContent.excludingDesktopWindows(false, onScreenWindowsOnly: true).windows let window = windows[0] let filter = SCContentFilter(desktopIndependentWindow: window) let configuration = SCStreamConfiguration() configuration.ignoreShadowsSingleWindow = false configuration.showsCursor = false configuration.width = Int(Float(filter.contentRect.width) * filter.pointPixelScale) configuration.height = Int(Float(filter.contentRect.height) * filter.pointPixelScale) print(filter.contentRect) let windowImage = try await SCScreenshotManager.captureImage(contentFilter: filter, configuration: configuration) imageView.image = NSImage(cgImage: windowImage, size: CGSize(width: windowImage.width, height: windowImage.height)) } } }

Here is the demo from Apple's site This issues is specific to iOS 18. When running this demo, we are getting new text when we have a gap in speaking, the recognitionTask(with:resultHandler:) provides new text which is only spoken after the gap and not the concatenation of old text and the new spoken text.

Hello, I have a command line application that uses iTunesLibrary to "save" the state of what I have listened to. I have it run every night via a LaunchAgent. You can see the source here: https://github.com/bolsinga/itunes_json Prior to Sequoia it would run nightly. I'd just have to grant it access to the Music library once, and it would be fine thereafter. However with Sequoia it requires UI interaction to grant it access every time. This makes it no longer run unattended overnight, defeating its purpose. I have the console logs of when this happens. You can see it in my issue tracking it here: https://github.com/bolsinga/itunes_json/issues/410 One thing that makes me wonder is that it is a command line application, not a bundle. How do I make a command line application get access to MusicKit / iTunesLibrary, and keep it thereafter? I'd like to get my pre-Sequoia behavior back. I've filed FB15592660 too. I've granted it access to run in the background, as well as access to my Music library (please see attached screenshots). AMPLibraryAgent 10:48:29.489944-0700 xpc Connection from framework client invalidated pid:57606 clientname:iTunesLibrary(itunes_json) AMPLibraryAgent 10:48:29.492763-0700 service Unloading domains(14) for ClientID:iTunesLibrary(itunes_json)-1229 previous open:15 new open:1 itunes_json 10:48:59.980864-0700 connection [0x157f05800] activating connection: mach=true listener=false peer=false name=com.apple.amp.library.framework tccd 10:48:59.982568-0700 access AUTHREQ_ATTRIBUTION: msgID=1795.214, attribution={accessing={TCCDProcess: identifier=itunes_json, pid=57652, auid=501, euid=501, binary_path=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json}, requesting={TCCDProcess: identifier=com.apple.AMPLibraryAgent, pid=1795, auid=501, euid=501, binary_path=/System/Library/PrivateFrameworks/AMPLibrary.framework/Versions/A/Support/AMPLibraryAgent}, }, tccd 10:48:59.982651-0700 access requestor: TCCDProcess: identifier=com.apple.AMPLibraryAgent, pid=1795, auid=501, euid=501, binary_path=/System/Library/PrivateFrameworks/AMPLibrary.framework/Versions/A/Support/AMPLibraryAgent is checking access for accessor TCCDProcess: identifier=itunes_json, pid=57652, auid=501, euid=501, binary_path=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json tccd 10:48:59.995636-0700 access AUTHREQ_SUBJECT: msgID=1795.214, subject=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json, tccd 10:48:59.996283-0700 access -[TCCDAccessIdentity staticCode]: static code for: identifier /Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json, type: 1: 0xc00341b00 at /Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json tccd 10:49:00.018205-0700 access Failed to match existing code requirement for subject /Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json and service kTCCServiceMediaLibrary cdhash H"6bc380972f4df49b337a2a05308fb7b98fbe6473" or cdhash H"0708bcaabbfbab8770522050f7e2642d4d864f31" cdhash H"6bc380972f4df49b337a2a05308fb7b98fbe6473" or cdhash H"0708bcaabbfbab8770522050f7e2642d4d864f31" tccd 10:49:00.018997-0700 access AUTHREQ_PROMPTING: msgID=1795.214, service=kTCCServiceMediaLibrary, subject=Sub:{/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json}Resp:{TCCDProcess: identifier=itunes_json, pid=57652, auid=501, euid=501, binary_path=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json}, AMPLibraryAgent 10:49:02.489170-0700 xpc ampld> register framework ClientName:iTunesLibrary(itunes_json) tccd 10:49:02.488189-0700 events Publishing <TCCDEvent: type=Create, service=kTCCServiceMediaLibrary, identifier_type=Path, identifier=/Users/bolsinga/Applications/itunes_json/Products/usr/local/bin/itunes_json> to 4 subscribers: { 633 = "<TCCDEventSubscriber: token=633, state=Initial, csid=(null)>"; 628 = "<TCCDEventSubscriber: token=628, state=Passed, csid=com.apple.chronod>"; 464 = "<TCCDEventSubscriber: token=464, state=Passed, csid=com.apple.cloudd>"; 513 = "<TCCDEventSubscriber: token=513, state=Passed, csid=com.apple.photolibraryd>"; } AMPLibraryAgent 10:49:02.490391-0700 xpc ampld> registered framework ClientName:iTunesLibrary(itunes_json) with clientID:1230 itunes_json 10:49:02.792084-0700 connection [0x147e04340] activating connection: mach=true listener=false peer=false name=com.apple.amp.artworkd itunes_json 10:49:02.801482-0700 <Missing Description> openDatabase 0xe4af30f4493e5ef5 artwork folder Y '<private>' itunes_json 10:49:02.805087-0700 <Missing Description> openDatabase 0xf2db6e8d7672edc9 artwork folder Y '<private>' itunes_json 10:49:02.806736-0700 <Missing Description> openDatabase 0xfb2acd898c951851 artwork folder Y '<private>' itunes_json 10:49:02.813286-0700 <Missing Description> openDatabase 0xf0f4919c5ff0e88 artwork folder Y '<private>' itunes_json 10:49:09.634928-0700 connection [0x600002b6a0d0] activating connection: mach=true listener=false peer=false name=com.apple.cfprefsd.daemon itunes_json 10:49:09.635019-0700 connection [0x600002b78000] activating connection: mach=true listener=false peer=false name=com.apple.cfprefsd.agent AMPLibraryAgent 10:49:12.382878-0700 xpc Connection from framework client invalidated pid:57652 clientname:iTunesLibrary(itunes_json) AMPLibraryAgent 10:49:12.383474-0700 service Unloading domains(14) for ClientID:iTunesLibrary(itunes_json)-1230 previous open:15 new open:1 itunes_json.log