HD-SDI - Computer Definition
(High Definition-Serial Digital Interface) An interface for professional broadcasting and surveillance systems that supports 720p/1080p digital signals. Unlike Ethernet, SDI transmits over coaxial cable, which allows it to be used in existing surveillance networks. For example, a hybrid DVR, which supports both analog and digital, allows HD-SDI cameras to co-exist with earlier analog cameras. See SDI and HD Analog.