HDMI-CEC
Consumer Electronics Control — extra signal wire in HDMI cable that lets devices control each other. TV + soundbar + Apple TV via one remote, auto-switch input on power-on, auto-turn-off on HDMI source off. Vendor-specific names: Anynet+ (Samsung), Bravia Sync (Sony), Simplink (LG).
Use case: press play on Apple TV → TV turns on, switches to correct input, soundbar powers on. Auto-Standby: TV-off → connected devices power down. Default off on many modern TVs — must be enabled in settings. ARC/eARC (Audio Return Channel) related: TV sends audio to soundbar over same HDMI. Anti-feature: cheap HDMI switches break CEC. CEC can control Raspberry Pi (libcec) — Kodi builds use TV remote for media control.