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At 3:38-4:00 in the session video, it seems Baek San Chang says that AudioDriverKit will not be allowed to be used for virtual audio devices... Keep in mind that the sample code presented is purely for demonstrative purpses and creates a virtual audio driver that is not associated with a hardware device, and so entitlements will not be granted for that kind of use case. For virtual audio driver, where device is all that is needed, the audio server plugin driver model should continue to be used. The mentioning of sample code is a little confusing; Does he mean the entitlements for hardware access won't be granted for a virtual device? That would seem obvious. But if he means the entitlements for driver kit extensions (com.apple.developer.driverkit and com.apple.developer.driverkit.allow-any-userclient-access) won't be granted for virtual audio devices, and this is why AudioServerPlugins should still be used, then that's another story. Are we allowed to use AudioDriverKit Extension for Virtual Devices? The benefit of having the extension bundled with the app rather than requiring an installer is a significant reason to use an extension if allowed.

What I'm looking to do is load a movie file and have it playback in real-time (synchronized with a particular clock) and have video and audio samples fed to me in the format I want (a lot like the AVCapture APIs do). When using an AVPlayer + AVPlayerItem, I can create a AVPlayerItemVideoOutput to get the video frames. Great. For audio though, it requires using a MTAudioProcessingTap added into the player item's audioMix.What's really odd about MTAudioProcessingTap on a player item is that I'm apparently at the mercy of whatever audio format AVFoundation wants to give me. There's seemingly no guarantee on what the format will look like. Compressed? LPCM? Floating point? Integer? Interleaved? Sample rate? I'm betting it's always at least floating LPCM (a canonical/Standard format), but what about sample rate? That I have no control over, and in my situation I need/want the sample rate to be a specific rate. (As well as wanting mixed down to stereo [or split up from mono].)Having no choice over the format is really inconvenient, because it seems that I have to convert the audio coming out of the tap. The real unfortunate part of this is that when sample rate conversion is involved, it seems there's a need to have an intermediate (small) ring buffer between the tap and the audio conversion because of the potentially fractional ratio of input:output frames in the conversion, and needing to keep the unused input frames from one tap "process" callback around until the next tap "process" callback where they would be used.Anybody following me? Am I wrong? Is there no simpler way to simply get the AVPlayerItem's audio fed to me in real-time in my specified format? I find it hard to imagine I'm the first going down this path, but so far I can't find any info from anyone's prior experience.