Editing Digital Visual Interface (section)

==Technical overview==
DVI's digital video transmission format is based on [[panelLink]], a serial format developed by [[Silicon Image Inc.|Silicon Image]] that utilizes a high-speed serial link called [[Transition Minimized Differential Signaling|transition minimized differential signaling]] (TMDS).

===TMDS===
Digital video [[pixel]] data is transported using multiple TMDS [[twisted pair]]s. At the electrical level, these pairs are highly resistant to [[electrical noise]] and other forms of analog [[distortion]].

====Single link====
A ''single link'' DVI connection has four TMDS pairs. Three data pairs carry their designated 8-bit RGB component (red, green, or blue) of the video signal for a total of 24&nbsp;bits per [[pixel]]. The fourth pair carries the TMDS clock. The binary data is encoded using [[8b/10b encoding]]. DVI does not use [[packet (information technology)|packetization]], but rather transmits the pixel data as if it were a [[rasterized]] analog video signal. As such, the complete frame is ''drawn'' during each vertical refresh period. The full active area of each frame is always transmitted without compression. Video modes typically use horizontal and vertical refresh timings that are compatible with [[cathode-ray tube]] (CRT) displays, though this is not a requirement. In single link mode, the maximum TMDS clock frequency is 165&nbsp;MHz, which supports a maximum resolution of 2.75&nbsp;[[megapixels]] (including [[blanking interval]]) at 60&nbsp;Hz refresh. For practical purposes, this allows a maximum 16:10 screen resolution of 1920&nbsp;×&nbsp;1200 at 60&nbsp;Hz.

====Dual link====
To support higher-resolution display devices, the DVI specification contains a provision for ''dual link''. Dual link DVI doubles the number of TMDS data pairs, effectively doubling the video bandwidth, which allows higher resolutions up to 2560&nbsp;×&nbsp;1600 at 60&nbsp;Hz or higher refresh rates for lower resolutions.

===Compatibility===
For [[backward compatibility]] with displays using analog VGA signals, some of the contacts in the DVI connector carry the analog VGA signals.

To ensure a basic level of interoperability, DVI compliant devices are required to support one baseline [[display mode]], "low pixel format" (640&nbsp;×&nbsp;480 at 60&nbsp;Hz).

===DDC===
Like modern analog [[VGA connector]]s, the DVI connector includes pins for the [[display data channel]] (DDC), which allows the graphics adapter to read the monitor's [[extended display identification data]] (EDID). When a source and display using the DDC2 revision are connected, the source first queries the display's capabilities by reading the monitor EDID block over an [[Inter-Integrated Circuit|I²C]] link. The EDID block contains the display's identification, color characteristics (such as gamma value), and table of supported video modes. The table can designate a preferred mode or [[native resolution]]. Each mode is a set of timing values that define the duration and frequency of the horizontal/vertical sync, the positioning of the active display area, the horizontal resolution, vertical resolution, and refresh rate.

===Cable length===
The maximum length recommended for DVI cables is not included in the specification, since it is dependent on the TMDS clock frequency. In general, cable lengths up to {{Convert|4.5|m}} will work for display resolutions up to 1920&nbsp;×&nbsp;1200. Longer cables up to {{Convert|15|m}} in length can be used with display resolutions 1280&nbsp;×&nbsp;1024 or lower. For greater distances, the use of a DVI booster—a signal repeater which may use an external power supply—is recommended to help mitigate signal degradation.