DVI, short for Digital Video Interface, is a device that was originally designed to produce high quality images on types of digital monitors. It was originally created by the Digital Display Working Group. Similar to HDMI (High Definition Multimedia Interface), it was designed to transfer uncompressed high quality high definition video content.

DVI to HDMI

HDMI and DVI signals are comparable to each in that they both deliver uncompressed digital video. DVI does not supply any type of audio data though. To transfer a signal via a DVI cable to an HDMI cable, an adapter is needed. In recent years, computer video card companies began implementing DVI into their cards. In order to avoid having to purchase a digital monitor specifically for the computer, an adapter was developed to convert the DVI plug to an HDMI capable signal that can be transferred to a high definition television.

Technical Specifications

The format that DVI uses to transfer data was developed by Silicon Image Inc. A DVI connection works by transmitting 24 bits of data per pixel via a red, green, blue, and clock wire. Because of the nature of the connection, it is impossible for a DVI signal to be “split” and only transmit the missing data of the picture. It must refresh the entire frame at the same time. Although, it has been rumored that this feature will be available in future versions.

Operating at a frequency of 60Hz, the largest possible resolution of a DVI connection is 2.75 megapixels. Resolutions may have to be greater than this so the DVI connection has a secondary link that may be activated. This added second link can provide resolutions up to 4 megapixels. When using a single link connection, the clock frequency is limited to anything up to 165Hz. Anything requiring a resolution that operates at greater than 165Hz must use the dual-link mode. DVI connectors are capable of transferring up to 1.65 gigabits per second on each data pair within the connector.

Connector Types

DVI connectors are backwards compatible to also transmit analog video via a VGA connection using a simple adapter. Because they are backwards compatible, each DVI connector is rated as to what it is capable of transmitting. DVI-A is capable of analog signals only. DVI-D is capable of digital signals only. DVI-I (Integrated) is capable of transmitting both analog and digital signals. In some cases, if a USB data transmission is also capable, a denotation of M1-DA is given. M1-DA is all of the capabilities in one. On devices that require a higher resolution of up to 4 megapixels, the adapter must be capable of dual link which is denoted as DVI-DL.

Device Implementation

Some devices such as DVD players use the DVI format. These DVI connections are usually the encrypted type and are encrypted using the HDCP (High-bandwidth Digital Content Protection) protocol.

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