Hello, I develop an audio processing demo app that has been working fine on iOS/iPad and on Mac ("developed for iPad") until I upgraded to MacOS27.
The app is demonstrating low latency / high temporal resolution audio spectral analysis. I am using AVAudioSession, I request the audio IO buffer to be 32 samples. This still works fine on iOS/iPadOS, but it seems that when running on MacOS27 the buffer size always defaults to 512 samples no matter what I request (smaller or larger). This applies to the "Designed for iPad" version running on MacOS and any version running in the iPhone and iPad simulators on MacOS. The app seems to be working as intended on physical iPhones and iPads.
I made a catalyst version and used AudioObjectSetPropertyData to force the IO bugger sizes to 32 samples on the system's active hardware device. This seems to succeed but still results in incorrect behaviour in my app; I am still diagnosing but I believe it's because this leaves AVAudioSession with incorrect data, and I am using AudioKit which relies on AVAudioSession (not confirmed).
Regardless, is this change in behaviour intentional in MacOS27? Is there a way around it? The whole point of my app is to demonstrate efficient audio processing with very low latency - I need small input buffer size for that.
Thank you for any help with this