I am developing a MacOS video/audio chat app that uses the audio input + audio only intermittently. The rest of the time I need to stop and tear down AVAudioEngine to allow other applications such as music players to use audio.
I have found that just pausing or stopping the engine is not enough, I need to completely tear it down and force a deinit by setting engine = nil in my objective C code (with ARC enabled).
What I have learned is that I have to make sure to tear down and detach absolutely everyhing, otherwise AVAudioEngine will fail to start the next time, especially when using a bluetooth headset. However, after months of trial and error, I have something that appears to be almost stable. However, I am sometimes hitting the crash show below after alloc + init of AVAudioEngine instance, when enabling voice processing. The crash is found when building with address-sanitizer enabled, and the logging above the line is my own:
stopping audio engine disabling voice processing... voice processing disabled engine stopped waiting for engine... starting audio engine... enabling voice processing...
==75508==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x000111e11be0 at pc 0x000103123360 bp 0x00016d231c90 sp 0x00016d231450 WRITE of size 52 at 0x000111e11be0 thread T218 #0 0x10312335c in wrap_memcpy+0x244 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x1b35c) (BuildId: f0a7ac5c49bc3abc851181b6f92b308a32000000200000000100000000000b00) #1 0x1077f407c (CoreAudio:arm64e+0xc07c) (BuildId: 3318bd64e64f3e69991d605d1bc10d7d32000000200000000100000000030d00) #2 0x1078f1484 (CoreAudio:arm64e+0x109484) (BuildId: 3318bd64e64f3e69991d605d1bc10d7d32000000200000000100000000030d00) #3 0x1a3d661a0 in AudioUnitGetProperty+0x1c0 (AudioToolboxCore:arm64e+0x2101a0) (BuildId: 3a76e12cd37d3545bb42d52848e0bd7032000000200000000100000000030d00) #4 0x207d8be38 in AVAudioIOUnit_OSX::_GetHWFormat(unsigned int, unsigned int*)+0x76c (AVFAudio:arm64e+0xbde38) (BuildId: 4a3f05007b8c35c98be4e78396ca9eeb32000000200000000100000000030d00) #5 0x207d8aea4 in invocation function for block in AVAudioIOUnit::IOUnitPropertyListener(void*, ComponentInstanceRecord*, unsigned int, unsigned int, unsigned int)+0x15c (AVFAudio:arm64e+0xbcea4) (BuildId: 4a3f05007b8c35c98be4e78396ca9eeb32000000200000000100000000030d00) #6 0x103149f74 in __wrap_dispatch_async_block_invoke+0xc0 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x41f74) (BuildId: f0a7ac5c49bc3abc851181b6f92b308a32000000200000000100000000000b00) #7 0x1a1d4a870 in _dispatch_call_block_and_release+0x1c (libdispatch.dylib:arm64e+0x2870) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #8 0x1a1d4c3fc in _dispatch_client_callout+0x10 (libdispatch.dylib:arm64e+0x43fc) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #9 0x1a1d53a84 in _dispatch_lane_serial_drain+0x298 (libdispatch.dylib:arm64e+0xba84) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #10 0x1a1d545f4 in _dispatch_lane_invoke+0x17c (libdispatch.dylib:arm64e+0xc5f4) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #11 0x1a1d5f240 in _dispatch_workloop_worker_thread+0x284 (libdispatch.dylib:arm64e+0x17240) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #12 0x1a1ef8070 in _pthread_wqthread+0x11c (libsystem_pthread.dylib:arm64e+0x3070) (BuildId: b401cfb38dfe32db92b3ba8af0f8ca6e32000000200000000100000000030d00) #13 0x1a1ef6d90 in start_wqthread+0x4 (libsystem_pthread.dylib:arm64e+0x1d90) (BuildId: b401cfb38dfe32db92b3ba8af0f8ca6e32000000200000000100000000030d00)
0x000111e11be0 is located 0 bytes to the right of 32-byte region [0x000111e11bc0,0x000111e11be0) allocated by thread T218 here: #0 0x10314ae68 in wrap_malloc+0x94 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x42e68) (BuildId: f0a7ac5c49bc3abc851181b6f92b308a32000000200000000100000000000b00) #1 0x207d8bdd4 in AVAudioIOUnit_OSX::_GetHWFormat(unsigned int, unsigned int*)+0x708 (AVFAudio:arm64e+0xbddd4) (BuildId: 4a3f05007b8c35c98be4e78396ca9eeb32000000200000000100000000030d00) #2 0x207d8aea4 in invocation function for block in AVAudioIOUnit::IOUnitPropertyListener(void*, ComponentInstanceRecord*, unsigned int, unsigned int, unsigned int)+0x15c (AVFAudio:arm64e+0xbcea4) (BuildId: 4a3f05007b8c35c98be4e78396ca9eeb32000000200000000100000000030d00) #3 0x103149f74 in __wrap_dispatch_async_block_invoke+0xc0 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x41f74) (BuildId: f0a7ac5c49bc3abc851181b6f92b308a32000000200000000100000000000b00) #4 0x1a1d4a870 in _dispatch_call_block_and_release+0x1c (libdispatch.dylib:arm64e+0x2870) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #5 0x1a1d4c3fc in _dispatch_client_callout+0x10 (libdispatch.dylib:arm64e+0x43fc) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #6 0x1a1d53a84 in _dispatch_lane_serial_drain+0x298 (libdispatch.dylib:arm64e+0xba84) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #7 0x1a1d545f4 in _dispatch_lane_invoke+0x17c (libdispatch.dylib:arm64e+0xc5f4) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #8 0x1a1d5f240 in _dispatch_workloop_worker_thread+0x284 (libdispatch.dylib:arm64e+0x17240) (BuildId: 8e87dc0ea5703933b37d5e05ad51620632000000200000000100000000030d00) #9 0x1a1ef8070 in _pthread_wqthread+0x11c (libsystem_pthread.dylib:arm64e+0x3070) (BuildId: b401cfb38dfe32db92b3ba8af0f8ca6e32000000200000000100000000030d00) #10 0x1a1ef6d90 in start_wqthread+0x4 (libsystem_pthread.dylib:arm64e+0x1d90) (BuildId: b401cfb38dfe32db92b3ba8af0f8ca6e32000000200000000100000000030d00)
This is on a Macbook M2 Pro running MacOS 13.3.1 (a) (22E772610a).
What is the best way to proceed with this, it looks to me like a bug in AVAudioEngine/CoreAudio.
Best regards, Jacob Gorm Hansen