Optional: video recording

JNEXT can record a session to an MP4 (chapter 5.5). That feature — and only that feature — needs ffmpeg installed and on your PATH. Everything else works without it.

JNEXT does not bundle ffmpeg: it runs whichever ffmpeg it finds on your PATH, so you install it the same way you install anything else on your system.

Platform	Install
Fedora / RHEL	sudo dnf install ffmpeg
Debian / Ubuntu	sudo apt install ffmpeg
macOS	brew install ffmpeg
Windows	winget install ffmpeg, or unpack a build from ffmpeg.org and put ffmpeg.exe on your PATH. Windows support landed in issue #56; it was verified by cross-build only, not yet exercised on real Windows hardware, so please report problems on the issue tracker.

Restart JNEXT after installing — it checks for ffmpeg once at startup, so a running instance still shows recording as unavailable.