Editing Digital Visual Interface (section)

====Digital data encoding====
One of the purposes of DVI stream encoding is to provide a [[DC-balanced]] output that reduces decoding errors. This goal is achieved by using 10-bit symbols for 8-bit or less characters and using the extra bits for the DC balancing.

Like other ways of transmitting video, there are two different regions: the active region, where pixel data is sent, and the control region, where synchronization signals are sent. The active region is encoded using [[transition-minimized differential signaling]], where the control region is encoded with a fixed [[8b/10b encoding]]. As the two schemes yield different 10-bit symbols, a receiver can fully differentiate between active and control regions.

When DVI was designed, most computer monitors were still of the [[cathode-ray tube]] type that require analog video synchronization signals. The timing of the digital synchronization signals matches the equivalent analog ones, so the process of transforming DVI to and from an analog signal does not require extra (high-speed) memory, expensive at the time.

[[High-bandwidth Digital Content Protection|HDCP]] is an extra layer that transforms the 10-bit symbols before transmitting. Only after correct authorization can the receiver undo the HDCP encryption. Control regions are not encrypted in order to let the receiver know when the active region starts.