disable audio on lock από Oleksandr Molodchyk

disable audio on lock stops Firefox audio when your Windows session locks.

The add-on listens for local Windows lock/unlock events through Firefox native messaging, then mutes Firefox tabs, pauses HTML audio and video, suspends Web Audio contexts used by custom sound apps, and blocks new playback attempts while the computer is locked.

When Windows unlocks, the add-on restores only the tabs it muted. It does not add a popup, settings page, analytics, tracking, or remote service.

This add-on is built for the case where music, video, or ambient sound pages continue playing behind the Windows lock screen.

disable audio on lock is open source. Source code, build scripts, and the native messaging host are available at:
https://github.com/molodchyk/disable-audio-on-lock