When getting CoreAudio properties for an audio device source on macOS, make sure the source is active and initialized before trying to read channel information.
Motivation and Context
If we had an audio device source on macOS, and that device was subsequently disconnected from the machine, OBS would uninitialize the source, freeing the data associated with the audio channels. libobs however would still see the channel layout information, and when trying to get the source properties, would read from the previously freed channel data.
Description
When getting CoreAudio properties for an audio device source on macOS, make sure the source is active and initialized before trying to read channel information.
Motivation and Context
If we had an audio device source on macOS, and that device was subsequently disconnected from the machine, OBS would uninitialize the source, freeing the data associated with the audio channels. libobs however would still see the channel layout information, and when trying to get the source properties, would read from the previously freed channel data.
Fixes https://github.com/obsproject/obs-studio/issues/11432, https://obsproject.com/forum/threads/crash-on-macos.181702/
Some other issues still abound in this code, and it is somewhat due for improvement, but for now, important to fix what is actually crashing.
How Has This Been Tested?
Tested locally on macOS 15.1; first reproduced the crash per the instructions in #11432. With the patch applied, the crash no longer occurs.
Types of changes
Checklist: