HDMI (High-Definition Multimedia
Interface) is the first industry-supported, uncompressed,
all-digital audio/video interface. HDMI provides an interface
between any audio/video source, such as a set-top box, DVD
player, and A/V receiver and an audio and/or video monitor, such
as a digital television (DTV).
HDMI supports standard, enhanced, or high-definition video, plus
multi-channel digital audio on a single cable. It transmits all
ATSC HDTV standards and supports 8-channel digital audio, with
bandwidth to spare to accommodate future enhancements and
requirements.HDMI is an
interface standard used for audiovisual equipment such as
high-definition television and home theater systems. With 19
wires wrapped in a single cable that resembles a USB wire, HDMI
is able to carry a bandwidth of 5 Gbps (gigabits per second).
This is more than twice the bandwidth needed to transmit
multi-channel audio and video, future-proofing HDMI for some
time to come. This and several other factors make HDMI much more
desirable than its predecessors, component video, S-Video and
composite video.
HDMI is an uncompressed, all-digital signal, while the
aforementioned interfaces are all analog. With an analog
interface, a clean digital source is translated into less
precise analog, sent to the television, then converted back to a
digital signal to display on screen. At each translation, the
digital signal loses integrity, resulting in some distortion of
picture quality. HDMI preserves the source signal, eliminating
analog conversion to deliver the sharpest, richest picture
possible.
Previous video interfaces required separate audio cables, with
the vast majority of people using standard RCA L/R analog audio
jacks. HDMI, with its abundant bandwidth and speed, carries not
only video but also up to eight digital audio channels for
uncompromised surround-sound. It replaces the tangle of wires
behind the system with a single cable, greatly simplifying the
entire setup process of the home theater system while delivering
top tier performance.
Though standard HDMI or "Type A" has 19 wires, "Type B" will
have 29 wires. The latter is targeted for the motion picture
industry and other professional applications. Both varieties are
"Intelligent HDMI," referring to the built-in capability for
HDMI-enabled components to talk to each other via the interface.
Auxiliary information can provide all-in-one remote
functionality and other interoperable features not possible in
previous interface technologies.
HDMI supports standard video formats, enhanced video and
high-definition. It is also backwards compatible with DVI
(Digital Video Interface). High-end graphics cards featuring a
DVI port can connect to a HDMI interface via a DVI/HDMI cable.
This is simply a cable with a DVI connector on one end and a
HDMI connector on the other. As a rule, HDMI cables should not
run longer than 15 feet (5 meters), or degradation of the signal
could occur. |
