I am struggling to see why the following low-level audio recording function - which is based on tn2091 - Device input using the HAL Output Audio Unit - (a great article, btw, although a bit dated, and it would be wonderful if it was updated to use Swift and non deprecated stuff at some point!) fails to work under macOS: func createMicUnit() -> AUAudioUnit { let compDesc = AudioComponentDescription( componentType: kAudioUnitType_Output, componentSubType: kAudioUnitSubType_HALOutput, // I am on macOS, os this is good componentManufacturer: kAudioUnitManufacturer_Apple, componentFlags: 0, componentFlagsMask: 0) return try! AUAudioUnit(componentDescription: compDesc, options: []) } func startMic() { // mic permision is already granted at this point, but let's check let status = AVCaptureDevice.authorizationStatus(for: AVMediaType.audio) precondition(status == .authorized) // yes, all good let unit = createMicUnit() unit.isInputEnabled = true unit.isOutputEnabled = false precondition(!unit.canPerformInput) // can't record yet, and know why? print(deviceName(unit.deviceID)) // "MacBook Pro Speakers" - this is why let micDeviceID = defaultInputDeviceID print(deviceName(micDeviceID)) // "MacBook Pro Microphone" - this is better try! unit.setDeviceID(micDeviceID) // let's switch device to mic precondition(unit.canPerformInput) // now we can record print("\(String(describing: unit.channelMap))") // channel map is "nil" by default unit.channelMap = [0] // not sure if this helps or not let sampleRate = deviceActualFrameRate(micDeviceID) print(sampleRate) // 48000.0 let format = AVAudioFormat( commonFormat: .pcmFormatFloat32, sampleRate: sampleRate, channels: 1, interleaved: false)! try! unit.outputBusses[1].setFormat(format) unit.inputHandler = { flags, timeStamp, frameCount, bus in fatalError("never gets here") // now the weird part - this is never called! } try! unit.allocateRenderResources() try! unit.startHardware() // let's go! print("mic should be working now... why it doesn't?") // from now on the (UI) app continues its normal run loop } All sanity checks pass with flying colors but unit's inputHandler is not being called. Any idea why? Thank you!

Using CoreBluetooth I am getting these values from CBCentralManagerDelegate's didDiscover peripheral delegate method: kCBAdvDataTxPowerLevel: 12 (could be other number like 7, 0 or a small negative number) This one is taken from advertisementData parameter. This key might be absent. rssi: -68 (or -60, -100, etc) this is taken from the "rssi" parameter (always present). I am looking for a formula to calculate approximate distance based on these two numbers. Is that possible? I know that ideally I need to know rssi0 (rssi at 1 meter), but I don't see how I can get that via CoreBluetooth API or other means (without actually measuring rssi at one meter distance which is not good for me). How could I approximate rssi0 value with "kCBAdvDataTxPowerLevel"?

Hi, is it possible to have the SwiftUI's NavigationView set to show both panels side by side in landscape mode on iPhone Plus/Max sized devices? Similar to how Messages.app does it. Thank you.

When calling CBCentralManager's connectPeripheral:options: with some Bluetooth devices I'm getting the "Bluetooth Pairing Request" alert on iOS and a similar "Connection Request from:" alert on macOS. Is there a way to determine upfront if the alert is going to be presented or not? Alternatively is there a way to prohibit presenting this alert (in which case the connect request could fail, which is totally fine)? I tried specifying these options: var manager: CBCentralManager ... manager.connect( peripheral, options: [ CBConnectPeripheralOptionNotifyOnConnectionKey: false, CBConnectPeripheralOptionNotifyOnDisconnectionKey: false, CBConnectPeripheralOptionNotifyOnNotificationKey: false ] ) but those didn't help (and by the doc they shouldn't help as they relate to the use case of app running in background, which is not applicable in my case – my app runs and calls connect when it is in foreground, the unwanted alert is displayed immediately).

Posting this on behalf of my colleague, who has a project in mind that requires a huge amount of RAM. Is it true that modern Mac Pro's can only have up to 192GB of RAM which is about 8 times less than 5 years old intel based Mac Pros?