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.

Hi all, I am developing a digital signal processing application using AudioToolbox to capture audio from an audio loop application (BlackHole). Environment: MacOS Sonoma 14.4.1 Xcode 15.4 Quicktime 10.5 (I also tested with JRive Media Center) BlackHole 2ch and 16ch Problem: All audio samples received are zero. Steps to recreate: Set Mac Settings Sound audio output to BlackHole 2ch. Set Mac Settings Sound audio input to BlackHole 2ch. Authorise Xcode to access Microphone. In Audio MIDI set "Use this device for sound input" and "Use this device for sound output". Set volume of both to 1.0 . Play a 44.1 16-bit signed integer stereo FLAC file using Quicktime. Start C++ application . Key details of my code below... AudioStreamBasicDescription asbd = { 0 }; asbd.mFormatID = kAudioFormatLinearPCM; asbd.mFormatFlags = kLinearPCMFormatFlagIsFloat | kLinearPCMFormatFlagIsPacked; asbd.mSampleRate = 48000; asbd.mBitsPerChannel = 32; asbd.mBytesPerFrame = 8; asbd.mChannelsPerFrame = 2; asbd.mBytesPerPacket = asbd.mBytesPerFrame; asbd.mFramesPerPacket = 1; status = AudioQueueNewInput(&asbd, read_audio_callback, &userdata, NULL, NULL, 0, &queue_ref); for (uint8_t b = 0; b < num_buffers; b++) { AudioQueueBufferRef buf_ref; status = AudioQueueAllocateBuffer(queue_ref, audio_buf_size, &buf_ref); printf("Allocate buffer status: %d length %d\n", status, buf_ref->mAudioDataByteSize); status = AudioQueueEnqueueBuffer (queue_ref, buf_ref, 0, NULL); printf ("Initial Enqueue Buffer status: %d\n", status); } status = AudioQueueStart(queue_ref, NULL); Here is my callback: void read_audio_callback(void * ptr, AudioQueueRef queue_ref, AudioQueueBufferRef buf_ref, const AudioTimeStamp * ts_not_used, uint32_t num_packets, const AudioStreamPacketDescription * aspd_not_used) { if (num_packets > 0) { uint32_t bytesize = buf_ref -> mAudioDataByteSize; float * sample_buf_float = (float *)buf_ref -> mAudioData; float data[bytesize / 4]; memcpy(data, sample_buf_float, bytesize); OSStatus status = AudioQueueEnqueueBuffer(queue_ref, buf_ref, 0, NULL); printf ("Enqueue buffer status: %d\n", status); printf("Buffer length %d Packets received %d\n", bytesize, num_packets); for (int j = 0; j < bytesize / 4; j++) { printf("%f",data[j]); } } printf("read_audio_callback called!\n"); } All calls to Apple Audio functions return status of 0. The samples in the buffer are all 0.0 . Why would this be the case? Also, my callback is called even when playback is stopped. num_packets is always > 0 . Appreciate any help. Thanks in advance, Geoff.

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?

The following is my playground code. Any of the apple audio units show the plugin view, however anything else (i.e. kontakt, spitfire, etc.) does not. It does not error, just where the visual is expected is blank. import AppKit import PlaygroundSupport import AudioToolbox import AVFoundation import CoreAudioKit let manager = AVAudioUnitComponentManager.shared() let description = AudioComponentDescription(componentType: kAudioUnitType_MusicDevice, componentSubType: 0, componentManufacturer: 0, componentFlags: 0, componentFlagsMask: 0) var deviceComponents = manager.components(matching: description) var names = deviceComponents.map{$0.name} let pluginName: String = "AUSampler" // This works //let pluginName: String = "Kontakt" // This does not var plugin = deviceComponents.filter{$0.name.contains(pluginName)}.first! print("Plugin name: \(plugin.name)") var customViewController:NSViewController? AVAudioUnit.instantiate(with: plugin.audioComponentDescription, options: []){avAudioUnit, error in var ilip = avAudioUnit!.auAudioUnit.isLoadedInProcess print("Loaded in process: \(ilip)") guard error == nil else { print("Error: \(error!.localizedDescription)") return } print("AudioUnit successfully created.") let audioUnit = avAudioUnit!.auAudioUnit audioUnit.requestViewController{ vc in if let viewCtrl = vc { customViewController = vc var b = vc?.view.bounds PlaygroundPage.current.liveView = vc print("Successfully added view controller.") }else{ print("Failed to load controller.") } } }

It’s been established that generally speaking background apps cannot record audio while the foreground app is already reading audio data from the microphone, but are there exceptions? For instance, is there an exception for certain Apple apps? If so, and there’s a special exception that most programmers don’t know about but some Apple’s engineers do and perhaps some hackers do as well, wouldn’t the mechanism that allows that eventually be exploited?

I'd like to know: Let's say there's a backgrounded app which has microphone access, such as Signal or SoundHound or Shazam. It's established that these apps are allowed to record audio in the user's environment even after being backgrounded, seemingly for as long as they want and even upload that sound data. But can they ALSO continue recording even while another app that is in the foreground is using the microphone, such as the Phone app or Signal?

I’m looking to add DAW-like capabilities to my macOS music app, and AVAudioEngine seems like the right tool for the job. However, I haven’t been able to find any documentation on how to save the user’s AVAudioEngine configuration—specifically the connections between nodes and the internal states of each node—to a file. Does AVAudioEngine provide any API for saving and restoring this state, or does it need to be handled manually? If it’s manual, are there any sample "DAW" apps or resources that demonstrate how this can be implemented? Any guidance would be greatly appreciated. Thanks, BD

Hello We have an application that play some sound via the system sound APIs from the AudioToolbox framework. AudioServicesCreateSystemSoundID(url as CFURL, &soundID) AudioServicesPlaySystemSoundWithCompletion(soundID) Our make sure that an active audio session is available before playing the system sound. But when the device is connected to a BluetoothA2DP device. The sound are played on through the device speaker and not through the bluetooth A2DP device. Our AudioSesison is configured with the following categories [.allowBluetooth, .defaultToSpeaker, .allowBluetoothA2DP] Sound played from the AVAudioPlayer are played on the allowBluetoothA2DP device with similar code. Is this a bug in the AudioToolbox framework?

I'm trying to make an app that is able to quietly run in the background. It needs to detect other apps' or the system's incoming video and/or audio, using only on-device resources to determine if it might be a scam caller. It will tap into an escalating cascade of resources to do so. For video/image scam detection, it uses OpenCV to detect faces, then refers to a known database of reported scam imagery. For audio scam calls, we defer to known techniques of voice modulation in frequency and/or amplitude. Each video and/or audio result will be relayed via notification banner as well as recorded in-app. Crucially, if the results are uncertain, users have the option to submit it to a global collaborative cloud database for investigative teams; 60 second audio snippets or series of images where faces were detected (60 second equivalent). In the end, we expect to deploy this app across most parts of Asia and Africa, thereby protecting generations of iPhone and iPad users. However, we have not been able to find a method that does this, and there is no known correspondance able to provide such technical guidance. Please assist.