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HDMI, DVI, and HDCP

From Matthew Torres,
Your Guide to TV / Video.
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High Speed and Copy Protected Digital

The following is a question posed to me by a reader:

If I purchase a new HDTV is it better to purchase one with DVI/HDCP? If I don't, how can it become DVI/HDCP-compliant? Some cable/satellite dealers have told me that a HDTV without DVI/HDCP is going to be useless in a year or two by around 2007 and unable to receive HD programming since those companies are probably heading in that direction. I want to purchase the right HDTV for the best viewing experience and one that will last me, at least, 7-10 years from now. Are these rumors true?

This is a good question, especially since over-the-air signals in the United States will become 100% digital after December 31, 2006, according to the Federal Communications Commission. It’s also a very complicated answer, so to keep things simple, let’s begin to answer by defining the technology at stake.

DIGITAL VIDEO

Digital video is standard (480i), enhanced (480p), and high definition (720p, 1080i, 1080p).

HDCP - HIGH-BANDWIDTH DIGITAL CONTENT PROTECTION

HDCP stands for High-Bandwidth Digital Content Protection and was developed by Intel Corporation. Politics aside, HDCP is a technology embraced by the Motion Picture Association of America as it eliminates the reproduction of copyrighted material.

DVI - DIGITAL VISUAL INTERFACE

DVI was created by the Digital Display Working Group, and stands for Digital Visual Interface. It allows for a high speed uncompressed connection between a digital television, personal computer, and other DVI-based consumer electronics devices. The input is something like you’d find on the back of your computer. One big benefit of DVI is the uncompressed transfer of high definition video.

While you don’t see it when you receive HD programming, it goes through a conversion from the source to the set-top box to your screen. Usually, component cables are used to transfer the red-blue-green signal. The advantage of DVI is that it only requires one cable to transfer the red-blue-green signal, and the speed it transfers an image is significantly faster than the analog component cables, which benefits the overall viewing experience on DLP, Plasma, and LCD televisions.

Combined with HDCP, DVI was the standard for digital television until a few years ago when HDMI was introduced.

HDMI - HIGH-DEFINITION MULTIMEDIA INTERFACE

HDMI stands for High-Definition Multimedia Interface, and like DVI, it allows for the uncompressed data transfer of video between a digital TV and HDMI-enabled consumer electronics devices. The big difference between HDMI and DVI is that HDMI transfers the video and audio signal. DVI only carries the video signal.

According to the HDMI’s official Web site, the advantages of HDMI are:

1) The highest quality video seen and audio heard
2) Fewer cables behind the TV means less mess and confusion-free connection
3) Automatically configures remote controls of devices connected by HDMI
4) Automatically adjusts video content to most effective format
5) HDMI is compatible with DVI, which means it will allow connection to PCs

Because it combines the audio and video signal, HDMI has tremendous support from the MPAA. It was created by some of the heavyweights in the consumer electronics industry - Hitachi, Matsushita, Philips, Silicon Image, Sony, Thomson, and Toshiba. The HDMI input is similar to a USB connector on a PC.

With a very simplistic understanding of the technology, it’s time to answer the original questions listed above:

If I purchase a new HDTV is it better to purchase one with DVI/HDCP?

Yes, you will want to purchase a television with DVI/HDCP or HDMI/HDCP. In my opinion, the best purchase option for a TV or any consumer electronics device (DVD player, DVR, set-top box) is one with HDMI/HDCP. DVI is an old format, and is secondary to HDMI. HDMI has room for growth, and because it has support from some of the major consumer electronics manufacturers, it’s hard to see it being replaced in the next decade or so. Regardless, buying a TV without either input would be a bad decision if you want to ensure usability of the TV a decade from now. Some televisions come with both inputs.

If I don't, how can it become DVI/HDCP-compliant?

Whether you have DVI or HDMI, there’s no way to convert the DVI or HDMI signal other than through a DVI or HDMI cable.

Some cable/satellite dealers have told me that a HDTV without DVI/HDCP is going to be useless in a year or two by around 2007 and unable to receive HD programming since those companies are probably heading in that direction. I want to purchase the right HDTV for the best viewing experience and one that will last me, at least, 7-10 years from now. Are these rumors true?

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