Digital video was first used to improve computer screen presentations and later for home entertainment systems. The technology started with digital video interface (DVI) for computer screens and evolved into high definition multimedia interface (HDMI) for home entertainment systems using high-definition screens. Since HDMI is more versatile, computer manufacturers now offer HDMI ports on laptops and on graphics cards for desktop computers.
DVI
Digital video interface first appeared in 1999 to present a digital video signal to flat screens for computers in order to replace the analog format, video graphics array (VGA). For a short time, some home entertainment system manufacturers added DVI ports to video equipment like DVD players, cable and satellite receivers, game consoles and television sets. Although some still add them, most have changed to the more versatile HDMI. DVI only carries video signals and not audio.
HDMI
Developed three years later in 2002, high definition multimedia interface provides an all digital video signal much the same as DVI, but adds up to eight channels of digital audio and an Ethernet channel to connect computers and home entertainment system components together with a single cable. Both computer and home entertainment equipment manufacturers are adding HDMI technology and ports for easier connections without the need for conversion. Systems connected with HDMI can receive Internet support via the Ethernet channel.
DVI to HDMI Adapter Cable
Since the video portion of DVI and HDMI are essentially the same, conversion cables can send the video signals from one format to another without the need for electronic conversion. However, signals included in HDMI but not in DVI, such as audio and Ethernet, need additional cables to make connections between equipment. Any video signal source with a DVI output can connect to an HDMI screen, or from an HDMI source to a DVI screen, with such an adapter cable.
Audio Connections
For a video signal source using DVI to make an audio connection to an HDMI device, the source must have auxiliary analog audio output connectors and the HDMI device must have auxiliary analog audio input connectors. Most equipment that has this option uses RCA "push-in" type connectors color-coded red for the right audio channel and white for the left. Since DVI to HDMI conversion does not transfer audio, some system configurations present an audio connection problem that the user must work around, depending on the equipment options.
Tags: home entertainment, video signal, analog audio, audio connection, audio Ethernet, auxiliary analog, auxiliary analog audio