Hi, Recently I encountered troubles uploading a binary with temporary-exception.audio-unit-host entitlement using Transporter. I would love to make use of in my application and distribute in the AppStore. What is necessary to do so? regards, Joël

hi, Is there an Audio Unit logo I can show on my website? I would love to show that my application is able to host Audio Unit plugins. regards, Joël

Hi, I have just implemented an Audio Unit v3 host. AgsAudioUnitPlugin *audio_unit_plugin; AVAudioUnitComponentManager *audio_unit_component_manager; NSArray<AVAudioUnitComponent *> *av_component_arr; AudioComponentDescription description; guint i, i_stop; if(!AGS_AUDIO_UNIT_MANAGER(audio_unit_manager)){ return; } audio_unit_component_manager = [AVAudioUnitComponentManager sharedAudioUnitComponentManager]; /* effects */ description = (AudioComponentDescription) {0,}; description.componentType = kAudioUnitType_Effect; av_component_arr = [audio_unit_component_manager componentsMatchingDescription:description]; i_stop = [av_component_arr count]; for(i = 0; i < i_stop; i++){ ags_audio_unit_manager_load_component(audio_unit_manager, (gpointer) av_component_arr[i]); } /* instruments */ description = (AudioComponentDescription) {0,}; description.componentType = kAudioUnitType_MusicDevice; av_component_arr = [audio_unit_component_manager componentsMatchingDescription:description]; i_stop = [av_component_arr count]; for(i = 0; i < i_stop; i++){ ags_audio_unit_manager_load_component(audio_unit_manager, (gpointer) av_component_arr[i]); } But this doesn't show me Audio Unit v2 plugins, why? regards, Joël

Hi, I just started to develop audio unit hosting support in my application. Offline rendering seems to work except that I hear no output, but why? I suspect with the player goes something wrong. I connect to CoreAudio in a different location in the code. Here are some error messages I faced so far: 2025-08-14 19:42:04.132930+0200 com.gsequencer.GSequencer[34358:18611871] [avae] AVAudioEngineGraph.mm:4668 Can't retrieve source node to play sequence because there is no output node! 2025-08-14 19:42:04.151171+0200 com.gsequencer.GSequencer[34358:18611871] [avae] AVAudioEngineGraph.mm:4668 Can't retrieve source node to play sequence because there is no output node! 2025-08-14 19:43:08.344530+0200 com.gsequencer.GSequencer[34358:18614927] AUAudioUnit.mm:1417 Cannot set maximumFramesToRender while render resources allocated. 2025-08-14 19:43:08.346583+0200 com.gsequencer.GSequencer[34358:18614927] [avae] AVAEInternal.h:104 [AVAudioSequencer.mm:121:-[AVAudioSequencer(AVAudioSequencer_Player) startAndReturnError:]: (impl->Start()): error -10852 ** (<unknown>:34358): WARNING **: 19:43:08.346: error during audio sequencer start - -10852 I have implemented an AVAudioEngine based AudioUnit host. Here I instantiate player and effect: /* audio engine */ audio_engine = [[AVAudioEngine alloc] init]; fx_audio_unit_audio->audio_engine = (gpointer) audio_engine; av_format = (AVAudioFormat *) fx_audio_unit_audio->av_format; /* av audio player node */ av_audio_player_node = [[AVAudioPlayerNode alloc] init]; /* av audio unit */ av_audio_unit_effect = [[AVAudioUnitEffect alloc] initWithAudioComponentDescription:[((AVAudioUnitComponent *) AGS_AUDIO_UNIT_PLUGIN(base_plugin)->component) audioComponentDescription]]; av_audio_unit = (AVAudioUnit *) av_audio_unit_effect; fx_audio_unit_audio->av_audio_unit = av_audio_unit; /* audio sequencer */ av_audio_sequencer = [[AVAudioSequencer alloc] initWithAudioEngine:audio_engine]; fx_audio_unit_audio->av_audio_sequencer = (gpointer) av_audio_sequencer; /* output node */ [[AVAudioOutputNode alloc] init]; /* audio player and audio unit */ [audio_engine attachNode:av_audio_player_node]; [audio_engine attachNode:av_audio_unit]; [audio_engine connect:av_audio_player_node to:av_audio_unit format:av_format]; [audio_engine connect:av_audio_unit to:[audio_engine outputNode] format:av_format]; ns_error = NULL; [audio_engine enableManualRenderingMode:AVAudioEngineManualRenderingModeOffline format:av_format maximumFrameCount:buffer_size error:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("enable manual rendering mode error - %d", [ns_error code]); } ns_error = NULL; [[av_audio_unit AUAudioUnit] allocateRenderResourcesAndReturnError:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("Audio Unit allocate render resources returned error - ErrorCode %d", [ns_error code]); } Then I render in a dedicated thread. ns_error = NULL; [audio_engine startAndReturnError:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("error during audio engine start - %d", [ns_error code]); } [av_audio_sequencer prepareToPlay]; ns_error = NULL; [av_audio_sequencer startAndReturnError:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("error during audio sequencer start - %d", [ns_error code]); } [av_audio_player_node play]; while(is_running){ /* pre sync */ /* IO buffers */ av_output_buffer = (AVAudioPCMBuffer *) scope_data->av_output_buffer; av_input_buffer = (AVAudioPCMBuffer *) scope_data->av_input_buffer; /* fill input buffer */ /* schedule av input buffer */ frame_position = 0; // (gint64) ((note_offset * absolute_delay) + delay_counter) * buffer_size; av_audio_player_node = (AVAudioPlayerNode *) fx_audio_unit_audio->av_audio_player_node; AVAudioTime *av_audio_time = [[AVAudioTime alloc] initWithHostTime:frame_position sampleTime:frame_position atRate:((double) samplerate)]; [av_audio_player_node scheduleBuffer:av_input_buffer atTime:av_audio_time options:0 completionHandler:nil]; /* render */ ns_error = NULL; status = [audio_engine renderOffline:AGS_FX_AUDIO_UNIT_AUDIO_FIXED_BUFFER_SIZE toBuffer:av_output_buffer error:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("render offline error - %d", [ns_error code]); } } regards, Joël

Hello, I have an existing AUv3 instrument plugin. In the plug in, users can access files (audio files, song projects) via a UIDocumentPickerViewController In Logic Pro, (and some other hosts, but not all), the document picker is unable to receive touches, while a keyboard case is attached to the iPad. Removing the case (this is an Apple brand iPad case) allows the interactions to resume and allows me to pick files in the usual way. One of my users reports this non-responsive behavior occurs even after disconnecting their keyboard. I have fiddled with entitlements all day, and have determined that is not the issue, since the keyboard disconnection appears to fix it every time for me. Here is my, very boilerplate, presentation code : guard let type = UTType("com.my.type") else { return } let fileBrowser = UIDocumentPickerViewController(forOpeningContentTypes: [type]) fileBrowser.overrideUserInterfaceStyle = .dark fileBrowser.delegate = self fileBrowser.directoryURL = myFileFolderURL() self.present(fileBrowser, animated: true) {

Sequoia 15.4.1 (24E263) XCode: 16.3 (16E140) Logic Pro: 11.2.1 I’ve been developing a complex audio unit for Mac OS that works perfectly well in its own bespoke host app and is now well into its beta testing stage. It did take some effort to get it to work well in Logic Pro however and all was fine and working well until: The AU part is an empty app extension with a framework containing its code. The framework contains Swift code for the UI and C code for the DSP parts. When the framework is compiled using the Swift 5 compiler the AU will run in Logic with no problems. (I should also mention that AU passes the most strict auval tests). But… when the framework is compiled with Swift 6 Logic Pro cannot load it. Logic displays a message saying the audio unit could not be loaded and to contact the developer. My own host app loads the AU perfectly well with the Swift 6 version, so I know there’s nothing wrong with the audio unit. I cannot find any differences in any of the built output files except, of course, the actual binary code in the framework. I’ve worked for hours on this and cannot find a solution other than to build the framework in Swift 5. (I worked hard to get all the async code updated and working with Swift 6! so I feel a little cheated!) What is happening? Is this a bug in Logic? Is this a bug in Swift 6 compiler/linker? I’m at the Duh! hands in the air, tearing out hair stage! ( once again!)

I created a virtual audio device to capture system audio with a sample rate of 44.1 kHz. After capturing the audio, I forward it to the hardware sound card using AVAudioEngine, also with a sample rate of 44.1 kHz. However, due to the clock sources being unsynchronized, problems occur after a period of playback. How can I retrieve the clock source of the hardware device and set it for the virtual device?

Previously it was needed to attach XCode (16.3) to the AUHostingService. This does not show up in the list of attachable processes any more. Just attaching to Logic Pro skips all breakpoints. I am trying to debug output-configuration as Logic offers versions of our Plugin that employ mono outputs which we do not actually provide. Any hints how I can trace through the plug-ins init code??

I have an AUv3 that passes all validation and can be loaded into Logic Pro without issue. The UI for the plug in can be any aspect ratio but Logic insists on presenting it in a view with a fixed aspect ratio. That is when resizing, both the height and width are resized. I have never managed to work out what it is I need to do specify to Logic to allow the user to resize width or height independently of each other. Can anyone tell me what I need to specify in the AU code that will inform Logic that the view can be resized from any side of the window/panel?

I have a custom USB Audio Class 2 (UAC2) compatible device. When I connect this custom device to a MacBook with a configuration of up to 10 channels (16-bit), everything seems to work fine. However, when I increase the channel count to 12, the MacBook does not recognize the 12 channels. It only shows the channel count as 0. TN2274 is the only source where I found some information about Apple's Audio Class Drivers, but it doesn't mention any limitations regarding channel counts. Could you let me know the current limitations of the Audio Class Drivers on the latest macOS versions? What configuration should I use to get 12 channels working? P.S. I also found that a 12-channel, 8-bit configuration is detected by the MacBook, bit I want it to work with 16bits. For more detail please check FB17098863

Hi there! We have a suite of AudioUnit v2 plugins that have been shipped for some time as aufx plugins, and we are looking into MIDI-related platform upgrades, so we need a way to update these plugins to request MIDI from Logic (and other AU hosts) but avoid changing our AU type and subtype so we don't break existing sessions. Any ideas on how we can do this?

hi, i need to read wether the transport is playing or stopped but my current method that works for vst does not work for au. is there a lpx resource available for developers anywhere? if (auto* playHead = processor->getPlayHead()) { juce::AudioPlayHead::CurrentPositionInfo posInfo; if (playHead->getCurrentPosition(posInfo)) { bool isCurrentlyPlaying = posInfo.isPlaying; if (isCurrentlyPlaying != wasTransportPlaying) { if (isCurrentlyPlaying) { wasTransportPlaying = isCurrentlyPlaying; startAllTimers(); } else { wasTransportPlaying = isCurrentlyPlaying; stopAllTimers(); } } } } thanks :)

im currently trying to build even the most basic sample plugin. Xcode forces me to do cross-platofrm audio app. so there is immediately 2 targets. i developed my code, testing in logic, now im ready to deploy and cannot find the component file. i only see appex. so what is logic loading when im testing? please advise. i did all the info.plist stuff, added audio unit framework, im totally lost. my most exerienced contacts all tell me to go to juce. im not convinced. im at final steps. please advise

Hello All, It seems that it's "very easy" (😬) to implement a little Swift code inside the prepared AU using Xcode 16.2 on Sequoia 15.1.1 and a Mac Studio M1 Ultra, but my issue is that I finally don't know... where. The documentation says that I've to find the AudioUnitViewController.swift file and then modify the render block : audioUnit.renderBlock = { (numFrames, ioData) in // Process audio here } in the Xcode project automatically generated, but I didn't find such a file... If somebody can help me in showing where is the file to be modified, I'll be very grateful ! Thank you very much. J

I have spent a long time refactoring lots of older Swift code to compile without error in Swift 6. The app is a v3 audio unit host and audio unit. Having installed Sonoma and XCode 16 I compile the code using Swift 6 and it compiles and runs without any warnings or errors. My host will load my AU no problem. LOGIC PRO is still the ONLY audio unit host that will load native Mac V3 audio units and so I like to test my code using Logic. In Sonoma with XCode 16... My AU passes the most stringent AUVAL tests both in terminal and Logic pro. If I compile the AU source in Swift 5 Logic will see the AU, load it and run it without problems. But when I compile the AU in Swift 6 Logic sees the AU, will scan it and verify it passes the tests but will not load the AU. In XCode I see a log message that a "helper application failed to run" but the debugger never connects to the AU and I don't think Logic even gets as far as instantiating the AU. So... what is causing this? I'm stumped.. Developing AUv3 is a brain-aching maze of undocumented hurdles and I'm hoping someone might have found a solution for this one. Meanwhile I guess my only option is to continue using the Swift 5 compiler. (appending a little note just to mention that all the DSP code is written in C/C++, Swift is used mainly for the user interface and also does some offline thready work )

Hello! I used the Apple CA Playthrough example code that pipes audio between devices. It uses AudioUnit callbacks to pipe the input to an output device, and I created a system equalizer with it - however users reported it stopped working in macOS 15. I am getting the error HALPlugIn.cpp:552 HALPlugIn::DeviceGetCurrentTime: got an error from the plug-in routine, Error: 1937010544 (stop) for the output device and no sound coming out of the speakers. The error only occurs when using a virtual device as an input, not using the microphone. First I thought the problem was in the loopback driver, but it also does not work with other loopback drivers like Blackhole. STEPS TO REPRODUCE Install a virtual device, for example "brew install blackhole-2ch" and run the CAPlayThrough example code (you need to add Mic Permission in the info.plist). Then set your system audio output to the virtual device, select the device as input in CAPlayThrough and hit start. You should see the error in console. My question: What did change in macOS 15 that could cause this? Is it something with the new permission handling maybe?

Hi everyone, I’m encountering a crash in my app and need help understanding what’s causing it and how to resolve it. As stated in the crash report, the issue is caused by exceeding the system-wide per-process port limit. Can you tell me how to locate and identify why this is happening? Below are the full report of the crash log: crash.log Summary of Crash: ------------------------------------- Translated Report (Full Report Below) ------------------------------------- Incident Identifier: B509FF2B-C8D8-4E9F-B664-E24464CFD5F8 CrashReporter Key: b390cfe931a83efde49bd8b523023a275b55ef64 Hardware Model: iPhone14,2 Process: MyApp [22515] Path: /private/var/containers/Bundle/Application/F73212A7-4CB9-485A-A8B7-8114F4E9A9AB/MyApp.app/MyApp Identifier: com.beeasy.app.id.enterprise Version: 3.41.38-ID-MySDKMemory-12261114 (3.41.38-ID-MySDKMemory-12261114) Code Type: ARM-64 (Native) Role: Foreground Parent Process: launchd [1] Coalition: com.beeasy.app.id.enterprise [515] Date/Time: 2024-12-29 01:29:48.3023 +0800 Launch Time: 2024-12-26 16:38:36.7895 +0800 OS Version: iPhone OS 16.6.1 (20G81) Release Type: User Baseband Version: 2.80.01 Report Version: 104 Exception Type: EXC_RESOURCE (SIGKILL) Exception Codes: 0x000000000001c1d6, 0x0000000000000000 Termination Reason: PORT_SPACE 14123288431433990614 (Limit 115158 ports) Exceeded system-wide per-process Port Limit Triggered by Thread: 64 Thread 64 name: AURemoteIO::IOThread Thread 64 Crashed: 0 libsystem_kernel.dylib 0x20ce5eca4 mach_msg2_trap + 8 1 libsystem_kernel.dylib 0x20ce71b74 mach_msg2_internal + 80 2 libsystem_kernel.dylib 0x20ce71e4c mach_msg_overwrite + 540 3 libsystem_kernel.dylib 0x20ce5f1e8 mach_msg + 24 4 libEmbeddedSystemAUs.dylib 0x238bb2148 void* caulk::thread_proxy<std::__1::tuple<caulk::thread::attributes, AURemoteIO::IOThread::IOThread(AURemoteIO&, caulk::thread::attributes const&, caulk::mach::os_workgroup_managed const&)::'lambda'(), std::__1::tuple<>>>(void*) + 556 5 libsystem_pthread.dylib 0x22dcda6b8 _pthread_start + 148 6 libsystem_pthread.dylib 0x22dcd9b88 thread_start + 8

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'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 have a werid case that shouldn't happen according to https://forums.developer.apple.com/forums/thread/706390 I have an audio unit which runs in FCP and I want it to launch a sandboxed app as a child process. If I sign the child app with just "com.apple.security.app-sandbox" entitlement it crashes with SYSCALL_SET_PROFILE error. According to the article referenced above: "This indicates that the process tried to setup its sandbox profile but that failed, in this case because it already has a sandbox profile." This makes sense because audio units run in a sandboxed environment (in AUHostingService process). So I added "com.apple.security.inherit" to the entitlements plist and now I get "Process is not in an inherited sandbox." error. According to the article referenced above: "Another cause of a trap within _libsecinit_appsandbox is when a nonsandboxed process runs another program as a child process and that other program’s executable has the com.apple.security.app-sandbox and com.apple.security.inherit entitlements. That is, the child process wants to inherit its sandbox from its parent but there’s nothing to inherit." And this doesn't make sense at all. The first error indicates the child process is trying to create a sandboxed environment within a parent sandboxed environment while the second error indicates there's no a parent sandboxed environment... I specifically checked the child process has "com.apple.security.app-sandbox" and "com.apple.security.inherit" entitlements only. If I remove all entitlements from the child process it launches and runs fine from the audio unit plugin. And if I remove "com.apple.security.inherit" but leave "com.apple.security.app-sandbox" I can successfully launch the app in standalone mode (in Finder). For the testing puroses I use a simple Hello World desktop application generated by XCode (Obj-C). Does anybody have an idea what can be the reason for such a weird behavior?