– This changes everything!

When historians look back on this period, they may view the introduction of HDMI cables as more significant than the introduction of DTV/HDTV. Home entertainment equipment has been going through a shift from analog based to being digitally based. It began with the introduction of the Compact Disc (CD) back in 1982. Since that time we have seen a progression from analog VCR to DVD and DVR; the Walkman replaced by CD Walkman, and later by the MP3 player; and lately analog TV has been giving way to digital TV, and not just the sets themselves but the manner in which television programming is broadcast and received. Indeed everything has been going digital in home entertainment except for speakers and the wiring that connected everything together.

A group of consumer electronics companies, comprised of Hitachi, Matsushita (parent to Panasonic), Philips, Silicon Image, Sony, Thomson (parent to RCA) and Toshiba, got together and decided to bring the wiring into the digital age. Their goal was to design a digital interconnect cable to replace the analog cables in use today, and in so doing, change the way that home entertainment equipment communicated. Their solution is called High Definition Multimedia Interface (HDMI). It was introduced in 2002 and it has had a rapid rate of adoption into not only in HDTVs, Blu-ray and HD DVD players, but also in gaming consoles, set-to-boxes, computers and DVDs.

HDMI is a purely digital interconnection system, which carries audio and video on the same wire. Two key benefits of a digital connection system are:

• You avoid the need to convert the signal from digital to analog (so that it can travel across an analog cable), and from analog back to digital so that the digital device receiving the signal can process it.
• The quality of a digital signal doesn’t lose data and degrade as much as it would with analog transmission.

HDMI has global relevance, supporting not just the NTSC and ATSC video formats used in North America, Japan, Indonesia and most of South America, but it also supports the PAL format used in Europe and most of the rest of the world. HDMI can support all current video resolutions (480p, 720p, 1080i and 1080p), as well as the next generation 1440p and higher. In addition, it can also support all compressed and uncompressed audio formats, including Dolby TrueHD and DTS-HD Master Audio.

Having the ability to carry both audio and video on a single wire greatly simplifies connecting audio and video equipment together. With a typical home entertainment setup (receiver, DVD, TV), HDMI reduces your wire count to 2 from as high as 7 if you were using high fidelity Monster Cable (or similar) component video and optical audio cables. This reduces the unsightly “spaghetti” you see when you look behind home entertainment components, and more important, you get improved fidelity.

The latest revision to the original HDMI standard is version 1.3a, and most of the components introduced in 2007 are version 1.3a compliant. Version 1.3a addresses a lot of technical issues (doubling of the bandwidth to 340MHz or 10.2 Gbps; a 120Hz refresh rate, support for the xvYCC color space and a new mini-connector for use in portable devices) that are probably not that important to most consumers at this point. If you’re like me, it’s annoying to see characters’ lips move out of sync with the sound. Version 1.3a addresses this issue. This sync problem is a result of the different amount of processing required for audio and video portions of the content. Every time something is processed it introduces latency, and the difference in the amount latency introduced by separate audio and video processing causes the sync problem. With version 1.3a the two separate processes can share their latency information, and make adjustment in their timing to correct the sync problem.

One great thing about HDMI that doesn’t get much fanfare is the enabling of 2-way communication between devices. This, I believe, is the greatest benefit of HDMI, and it will make the introduction of HDMI more significant than the switch to DTV. The details of 2-way communications will be covered in a separate article.

Suffice to say, if you are considering purchasing any new home entertainment equipment, having an HDMI connection on that product is must! Don’t even consider any products that don’t have an HDMI connector.