Hi! I am creating a aumi AUv3 extension and I am trying to achieve simultaneous connections to multiple other avaudionodes. I would like to know it is possible to route the midi to different outputs inside the render process in the AUv3. I am using connectMIDI(_:to:format:eventListBlock:) to connect the output of the AUv3 to multiple AvAudioNodes. However, when I send midi out of the AUv3, it gets sent to all the AudioNodes connected to it. I can't seem to find any documentation on how to route the midi only to one of the connected nodes. Is this possible?

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?

For an upcoming update of one of my apps, I’m facing an issue: The .rate parameter of a AVAudioUnitTimePitch allows me to slow down an audio track without any issues: setting .rate to 0.7 or 0.8 results in an almost perfect playback without changing pitch. However, whenever the .rate parameter is greater than 1 (e.g. 1.1 or 1.15), I’m starting to hear audio artifacts (“flattering”) in the audio output which is not so nice (even at .overlap = 32). Intuitively, I’d’ve thought that speeding up the file should contain less artifacts than slowing it down?? I’ve tried different sample rates (44.1 kHz and 48 kHz), but same result. Grateful for any input on this 🙏

I’m working on a memo app that records audio from the iPhone’s microphone (and other devices like MacBook or iPad) and processes it in 10-second chunks at a target sample rate of 16 kHz. However, I’ve encountered limitations with installTap in AVAudioEngine, which doesn’t natively support configuring a target sample rate on the mic input (the default being 44.1 kHz). To address this, I tried using AVAudioMixerNode to downsample the mic input directly. Although everything seems correctly configured, no audio is recorded—just a flat signal with zero levels. There are no errors, and all permissions are granted, so it seems like an issue with downsampling rather than the mic setup itself. To make progress, I implemented a workaround by tapping and resampling each chunk tapped using installTap (every 50ms in my case) with AVAudioConverter. While this works, it can introduce artifacts at the beginning and end of each chunk, likely due to separate processing instead of continuous downsampling. Here are the key issues and questions I have: 1. Can we change the mic input sample rate directly using AVAudioSession or another native API in AVAudio? Setting up the desired sample rate initially would be ideal for my use case. 2. Are there alternatives to installTap for recording audio at a different sample rate or for continuously downsampling the live input without chunk-based artifacts? This issue seems longstanding, as noted in a 2018 forum post: https://forums.developer.apple.com/forums/thread/111726 Any guidance on configuring or processing mic input at a lower sample rate in real-time would be greatly appreciated. Thank you!

I'm experimenting with getting my AUv3 plugins working correctly on iOS and MacOS using Catalyst. I'm having trouble getting the plugin windows to look right in Logic Pro X on MacOS. My plugin is designed to look right in Garageband's minimal 'letterbox' layout (1024x335, or ~1:3 aspect ratio) I have implemented supportedViewConfigurations to help the host choose the best display dimensions On iOS this works, although Logic Pro iPad doesn't seem to call supportedViewConfigurations at all, only Garageband does. On MacOS, Logic Pro does call supportedViewConfigurations but only provides oversized screen sizes, making the plugins look awkward. I can also remove the supportedViewConfigurations method on MacOS, but this introduces other issues: I guess my question boils down to this: how do I tell Logic Pro X on MacOS what the optimal window size of my plugin is, using Mac Catalyst?

Somehow I have a corrupted audio plugin authentication problem. I’m on a silicon Mac M1 and two audio plugins that were installed and working will now not authenticate. The vendors both are unable to troubleshoot and I think the issue is a corrupted low level file. One product authenticates correctly when I created a new user but another plugin only authenticates on the original user account and not on the newly created user. Reinstalling the plugins and the Mac OS does not fix the issue. Any thoughts?