I’ve open-sourced atem-mini-emulator, a Windows C++/Qt 6 application for developing ATEM controller software without keeping a physical switcher connected.
The Qt window and a headless executable share the same protocol core. SDK clients can connect locally, change program/preview, transitions, PiP and macros, and see the resulting program picture rendered with QPainter. Camera inputs can use colours, stills or looping video files.
It targets the base ATEM Mini and is an MIT-licensed source build. Search GitHub for tin921/atem-mini-emulator; the README covers building and connecting, and docs/core.md explains the protocol implementation. Feedback from other Qt/network-tool developers is welcome.
[image: emulator.png]
Writing assistance: AI helped prepare this introduction from the project documentation.