Swift 4.1 Platforms: macOS & Linux

Atem network protocol implementation

Implementation of BlackMagicDesign’s ATEM communication protocol in Swift. It is written on top of Apple’s new networking library NIO and implements both sides of the protocol: the control panel and the switcher side. This means that you can not only use it to control atem switchers but also to connect to your control panels without the need for a switcher. Opening a whole new world of applications for the Atem control panels. An example can be found at Atem-Simulator

Tested platforms

  • macOS 10.13.4 on a MacBook Pro retina 15" late 2013
  • Raspbian GNU/Linux 9 stretch on a Raspberry Pi model 3 B


When starting a new project: create a Swift package via SPM

# Shell
> swift package init # --type empty|library|executable|system-module

Then add this library to the package description‘s dependencies

.package(url: "https://github.com/Dev1an/Swift-Atem", from: "0.1.0")

And resolve this new dependency

# Shell
> swift package resolve

Finally import the Atem module in your code

import Atem

You are now ready to create atem controllers and switchers 😎 !


After looking at the following examples, study the API reference for more details.


This example shows how to create a controller that connects to a swicther at ip address and print a message whenever the preview bus changes.

try Controller(ipAddress: "") { handler in
    handler.when{ (change: PreviewBusChanged) in
        print(change) // prints: 'Preview bus changed to input(x)'


The following example shows how to emulate the basic functionality of an atem switcher. It will forward incoming messages containing transition and preview & program bus changes to the connected controller.

try Switcher { handler in
    handler.when { (change: ChangePreviewBus) in
        return [PreviewBusChanged(to: change.previewBus, mixEffect: change.mixEffect)]
    handler.when{ (change: ChangeProgramBus) in
        return [ProgramBusChanged(to: change.programBus, mixEffect: change.mixEffect)]
    handler.when { (change: ChangeTransitionPosition) in
        return [
                to: change.position,
                remainingFrames: 250 - UInt8(change.position/40),
                mixEffect: change.mixEffect