HDMI - High-Definition Multimedia Interface

By: Preethi Ramkumar

Meaning of HDMI - "High-Definition Multimedia Interface" is an industry-supported, uncompressed, all-digital audio/video interface. HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, DVD player, and A/V receiver and a compatible digital 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 is independent of the various HDTV standards such as ATSC, DVB (-T,-S,-C), as these are encapsulations of the MPEG data streams, which are passed off to a decoder, and output as uncompressed high-resolution video data. This video data is then encoded into TMDS for transmission digitally over HDMI. HDMI also includes support for 8-channel uncompressed digital audio.  

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 and Samsung.

The standard Type A HDMI connector has 19 pins, and a higher resolution version called Type B, has been defined, although it is not yet in common use. Type B has 29 pins, allowing it to carry an expanded video channel for use with high-resolution displays. Type-B is designed to support resolutions higher than 1080i. Type A HDMI is backwards-compatible with the single-link Digital Visual Interface (DVI) used on modern computer monitors and graphics cards. This means that a DVI source can drive an HDMI monitor, or vice versa, by means of a suitable adapter or cable, but the audio and remote control features of HDMI will not be available. Additionally, without support for HDCP, the video quality and resolution may be downgraded by the player unit. Type B HDMI is similarly backwards-compatible with dual-link DVI.

Other Related Definitions:

“…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. ” [HDMI Licensing, LLC] 

“…High Definition Multimedia Interface Keeps TV at Center of Connected Home Television has transformed the way families enjoy their leisure time. However, in recent years televisions have also been changing, and lately the pace of change has accelerated dramatically. The arrival of new devices - starting with VCRs and cable TV set-top boxes, and most recently high-performance DVD-players - has raised customer expectations about television to new heights. The big challenge has been to find an elegant way to integrate each new development as part of the connected home. The answer may already be here in the form of a new high definition multimedia interface known as HDMI. [NE Asia ] 

“…The HD Multi-Media Interface is provided for transmitting digital TV audio-visual signals from DVD players, set-top boxes and other audio-visual sources to television sets, projectors and other video displays. HDMI cable assemblies can carry high quality multi-channel audio data and can carry all standard and high-definition consumer electronics video formats. Content protection technology is available. HDMI can also carry control and status information in both directions. “ [connectworld.net]

“…The HDMI interface is an all-digital interface, eliminating the signal degradation that occurs in the signal conversion process. A typical audio or video cable is designed to carry an analog signal from one device to another. The audio and video signals generated by a DVD player originate as digital signals. The DVD player must convert the digital signals to analog signals before sending the signals across the cables. Once the analog signals are received, they are then converted back to digital before being processed and displayed as a picture on a screen or heard sonically as music or voice. The analog to digital and digital to analog conversions reduce the integrity of the signal and degrade the quality of the audio and video. HDMI is an all-digital, uncompressed standard, using the original digital signal without the need for signal degrading conversions or compressions. ” [By Michael Weizer, Accell Corporation ] 

“…OCP Group, Inc. is pleased to announce that it has developed a line of High Definition Multimedia Interface (HDMI) Cable and Adapter products for the emerging standard. HDMI 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, A/V receiver and an audio or video monitor like Digital Television.” [GlobalSpec] 

Related Links:

How do consumers benefit from HDMI? – Matsushita Electric Industrial Co., Ltd
High-Definition Multimedia Interface, HDMI review – A1 Electronics.net
The HDMI interface – Very informative website
Latest news and analysis of HDMI – Toshiba
HDMI Receiver IC is suited for use in design of HDTVs – ThomasNet
CE companies define multimedia standard - The Circuit - Electronic News
Indiantelevision.com's TV Technology Update – HDMI founders release the final 1.0 specification

Products and Solutions:

Hitachi - Hitachi Cable Manchester, Inc.
High Definition Multimedia Interface (HDMI) Cable – TriState Electronics
HDMI Male to DVI Digital Dual Link – Directron - Computer Superstore
TOSHIBA's HDD-J35 high definition set-top box – Castel Electronics
Why HDMI? - Samsung

Books About:

Guide to High Definition Video Production, The : Preparing for a Widescreen World - by Clay Gordon

See Also:

HDMI Resources

(C) Copyright Birds-Eye.Net, All rights reserved.
It is against the law to reproduce this content or any portion of it in any form without the explicit written permission of Birds-Eye Network Services, LLC. Federal copyright law (17 USC 504) makes it illegal, punishable with fines up to $100,000 per violation plus attorney's fees.