What is HDMI?
HDMI (High-Definition Multimedia Interface) is the first and only 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, or A/V receiver and an audio and/or video monitor, such as a digital television (DTV), over a single cable.
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.

Who supports HDMI?
The HDMI Founders include leading consumer electronics manufacturers Hitachi , Matsushita Electric Industrial (Panasonic), Philips, Sony, Thomson (RCA), Toshiba, and Silicon Image. Digital Content Protection, LLC (a subsidiary of Intel) is providing High-bandwidth Digital Content Protection (HDCP) for HDMI. In addition, HDMI has the support of major motion picture producers Fox, Universal, Warner Bros. and Disney, and system operators DirecTV, EchoStar (Dish Network) as well as CableLabs.

How do consumers benefit from HDMI?
The new HDMI digital interconnect provides:

1. Superior, uncompressed digital video and audio quality
2. A simple, single cable and user-friendly connector that replaces the maze of cabling behind the entertainment center
3. Integrated remote control
4. A popular interface enabling the transmission of high-definition content. HDMI opens the floodgate of digital content from major motion picture producers

What is the life expectancy of HDMI?
HDTV uses less than 1/2 of HDMI's available 5 Gbps bandwidth. With capacity to spare, HDMI can incorporate new technology advancements and capabilities long into the foreseeable future.

What are the advantages of HDMI over existing analog interfaces such as composite, S-Video and component video?

Quality: HDMI transfers uncompressed digital audio and video for the highest, crispest image quality.

All-Digital: HDMI ensures an all-digital rendering of video without the losses associated with analog interfaces and their unnecessary digital-to-analog conversions.

Low-cost: HDMI provides the quality and functionality of a digital interface while also supporting uncompressed video formats in a simple, cost-effective manner.
Audio: HDMI supports multiple audio formats, from standard stereo to multi-channel surround-sound.

Ease-of-use: HDMI combines video and multi-channel audio into a single cable, eliminating the cost, complexity, and confusion of multiple cables currently used in A/V systems.

Intelligence: HDMI supports two-way communication between the video source (such as a DVD player) and the DTV, enabling new functionality.

Is HDMI backward-compatible with DVI (Digital Visual Interface)?
Yes, HDMI is fully backward-compatible with DVI using the CEA-861 profile for DTVs. HDMI DTVs will display video received from existing DVI-equipped products, and DVI-equipped TVs will display video from HDMI sources.

Will current HD TVs and set-top boxes using DVI-HDTV be compatible with HDMI devices?
Yes. Currently there are TVs with DVI-HDTV inputs available from a wide variety of manufacturers. These devices will be compatible with future HDMI-equipped products.

What types of video does HDMI support?
HDMI has the capacity to support existing high-definition video formats (720p, 1080i, and even 1080p). It also has the flexibility to support enhanced definition formats such as 480p, as well as standard definition formats such as NTSC or PAL.

Does HDMI support Dolby 5.1 audio and high-resolution audio formats?
Yes. From the start, HDMI was defined to carry 8-channels, of 192kHz, 24-bit uncompressed audio, which exceeds all current consumer media formats. In addition, HDMI can carry any flavor of compressed audio format such as Dolby or DTS. (Such compressed formats are the only multi-channel or high-resolution audio formats that can be carried across the older S/PDIF or AES/EBU interfaces.) The fact that the vast majority of HDMI products shipped are two-channel TVs that don’t support more than two-channel audio doesn’t make this any less the case. Most existing HDMI sources can output any compressed stream, and the newer sources can output uncompressed 6-channel, 96kHz audio from a DVD-Audio disk. There are several A/V receivers on the market that can accept and process the 6- or 8-channel audio from HDMI and more are expected to be available shortly.

Will HDMI support SACD?
The HDMI Founders designed the HDMI specification to be dynamic. HDMI has plenty of extra bandwidth to accommodate future audio and video requirements, and the Founders are committed to evaluating and updating the specification to help accommodate new audio and video formats that may be introduced in the foreseeable future. As an example, since the introduction of the initial HDMI 1.0 specification, the HDMI 1.1 specification supporting DVD-Audio has already been introduced. The HDMI Founders do not comment on future revisions of the spec, however there is no technical reason why HDMI could not support SACD.

How can a consumer identify which HDMI products support DVD Audio?
In most cases, any HDMI-equipped DVD player capable of supporting DVD-Audio will be capable of sending the DVD-Audio over the HDMI link. Consumers interested in confirming whether a particular consumer electronics product supports DVD-Audio over HDMI are urged to review users’ manuals and product reviews and check with manufacturers directly.

Does HDMI accommodate long cable lengths?
Yes. HDMI technology has been designed to use standard copper cable construction at long lengths. In order to allow cable manufacturers to improve their products through the use of new technologies, HDMI specifies the required performance of a cable but does not specify a maximum cable length. Cable manufacturers are expected to sell reasonably priced copper cables at lengths of up to 15 meters. As semiconductor technology improves, even longer stretches can be reached with fiber optic cables, and with active cable technologies such as amplifiers or repeaters