Awesome

🔊 SimplyCoreAudio

SimplyCoreAudio (formerly known as AMCoreAudio) is a Swift framework that aims to make Core Audio use less tedious in macOS.

Features

Enumerating audio devices (see SimplyCoreAudio)
Getting/setting default input, output and system device (see SimplyCoreAudio)
Creating and destroying aggregate devices (see SimplyCoreAudio)
Querying audio device properties such as: name, manufacturer, UID, volume, mute, sample rate, clock source, etc. (see AudioDevice)
Managing (physical and virtual) audio streams associated to an audio device (see AudioStream)
Subscribing to audio hardware, audio device, and audio stream notifications (see Notification Extensions)

Resources

Requirements

Xcode 12+
Swift 4.0+
macOS 10.12+

Installation

To install the Swift Package, please follow the steps below:

Add https://github.com/rnine/SimplyCoreAudio.git as a Swift Package Manager dependency to your project.
When asked to Choose Package Options, use the default settings provided by Xcode.
When asked to Add Package, add SimplyCoreAudio to your desired target(s).

Usage

Import SimplyCoreAudio
```
import SimplyCoreAudio
```
Instantiate SimplyCoreAudio
```
let simplyCA = SimplyCoreAudio()
```

Interact with SimplyCoreAudio

// Get the default output device
let device = simplyCA.defaultOutputDevice

// Get all output devices
simplyCA.allOutputDevices

// You can also filter devices by the scope needed
simplyCA.allDevices.filter { $0.channels(scope: .output) > 0 }

// For example, list all devices that aren't aggregate ones that support input 
simplyCA.allNonAggregateDevices.filter { $0.channels(scope: .input) > 0 }

// After you've chosen a device you can set it as the default.
// This will switch the selected device in the system
device.isDefaultOutputDevice = true

// Set the default input device to a new device
device.isDefaultInputDevice = true

// Get preferred output channels
if let stereoPair = device.preferredChannelsForStereo(scope: .output) {
    let leftChannel = stereoPair.left
    let rightChannel = stereoPair.right
    // Use channels...
}

// Get device samplerate
if let sampleRate = device.nominalSampleRate {
    // Use samplerate...
}

// Get device virtual main volume
if let outVolume = device.virtualMainVolume(scope: .output) {
    // Use output volume...
}

Subscribe to hardware-related notifications

// e.g., subscribing to `deviceListChanged` notification.
var observer = NotificationCenter.default.addObserver(forName: .deviceListChanged,
                                                       object: nil,
                                                        queue: .main) { (notification) in
    // Get added devices.
    guard let addedDevices = notification.userInfo?["addedDevices"] as? [AudioDevice] else { return }

    // Get removed devices.
    guard let removedDevices = notification.userInfo?["removedDevices"] as? [AudioDevice] else { return }
}

// Once done observing, remove observer and nil it.
NotificationCenter.default.removeObserver(observer)
observer = nil

Subscribe to notifications from a specific audio device

// Get the default output device
let device = simplyCA.defaultOutputDevice

// e.g., subscribing to `deviceNominalSampleRateDidChange` notification.
var observer = NotificationCenter.default.addObserver(forName: .deviceNominalSampleRateDidChange,
                                                       object: device,
                                                        queue: .main) { (notification) in
    // Handle notification.
}

// Once done observing, remove observer and nil it.
NotificationCenter.default.removeObserver(observer)
observer = nil

Subscribe to notifications from a specific audio stream

// Get the default output device
let device = simplyCA.defaultOutputDevice

// Get the first output stream
guard let streams = device.streams(scope: .output) else { return }
guard let stream0 = streams.first else { return }

// e.g., subscribing to `streamPhysicalFormatDidChange` notification.
var observer = NotificationCenter.default.addObserver(forName: .streamPhysicalFormatDidChange,
                                                       object: stream0,
                                                        queue: .main) { (notification) in
    // Handle notification.
}

// Once done observing, remove observer and nil it.
NotificationCenter.default.removeObserver(observer)
observer = nil

Supported Notifications

Audio Hardware Notifications

Name	Purpose	User Info
`defaultInputDeviceChanged`	Called whenever the default input device changes.	N/A
`defaultOutputDeviceChanged`	Called whenever the default output device changes.	N/A
`defaultSystemOutputDeviceChanged`	Called whenever the default system output device changes.	N/A
`deviceListChanged`	Called whenever the list of hardware devices and device subdevices changes.	`addedDevices: [AudioDevice]`, `removedDevices: [AudioDevice]`

Audio Device Notifications

Name	Purpose	User Info
`deviceNominalSampleRateDidChange`	Called whenever the audio device's sample rate changes.	N/A
`deviceAvailableNominalSampleRatesDidChange`	Called whenever the audio device's list of nominal sample rates changes.	N/A
`deviceClockSourceDidChange`	Called whenever the audio device's clock source changes.	N/A
`deviceNameDidChange`	Called whenever the audio device's name changes.
`deviceOwnedObjectsDidChange`	Called whenever the list of owned audio devices on this audio device changes.	N/A
`deviceVolumeDidChange`	Called whenever the audio device's volume for a given channel and scope changes.	`channel: UInt32`, `scope: Scope`
`deviceMuteDidChange`	Called whenever the audio device's mute state for a given channel and scope changes.	`channel: UInt32`, `scope: Scope`
`deviceIsAliveDidChange`	Called whenever the audio device's list of nominal sample rates changes.	N/A
`deviceIsRunningDidChange`	Called whenever the audio device's is running property changes.	N/A
`deviceIsRunningSomewhereDidChange`	Called whenever the audio device's is running somewhere property changes.	N/A
`deviceIsJackConnectedDidChange`	Called whenever the audio device's is jack connected property changes.	N/A
`devicePreferredChannelsForStereoDidChange`	Called whenever the audio device's preferred channels for stereo property changes.	N/A
`deviceHogModeDidChange`	Called whenever the audio device's hog mode property changes.	N/A

Audio Stream Notifications

Name	Purpose	User Info
`streamIsActiveDidChange`	Called whenever the audio stream `isActive` flag changes state.	N/A
`streamPhysicalFormatDidChange`	Called whenever the audio stream physical format changes.	N/A

Further Development & Patches

Do you want to contribute to the project? Please fork, patch, and then submit a pull request!

Running Tests

Please make sure to install NullAudio.driver before attempting to run tests:

Installing `NullAudio.driver`

Download and build NullAudio.driver located at:

Creating an Audio Server Driver Plug-in

Install into the system HAL Plug-Ins folder
```
/Library/Audio/Plug-Ins/HAL
```

Reload coreaudiod

sudo launchctl kill KILL system/com.apple.audio.coreaudiod

Demo Project

SimplyCoreAudioDemo — a basic SwiftUI-based demo showcasing device enumeration and notifications.

License

SimplyCoreAudio was written by Ruben Nine (@rnine) in 2013-2014 (open-sourced in March 2014) and is licensed under the MIT license. See LICENSE.md.