Introduction

HDTV: Coming to a PC near you

Slowly but surely, digital technology is playing an increasing role in the lives of not just technophiles, but your typical “average Joe” consumer as well: satellite providers have offered digital service since their inception, even the good ‘ol telephone is beginning to go digital. This transition is occurring in the television sector as well. In fact, many believe the arrival of digital television is the most significant advance in television technology since the introduction of color in the 1950s.

By 2006 the FCC has mandated that all television broadcasting be digital. At that point, the FCC will begin to phase out current analog NTSC TV broadcasting, a system that has been in place in America for over 50 years. In fact, already over 82% of American households get five or more DTV channels, while 56% of US homes get eight or more digital stations. Basically, if you live in a major population center, chances are you can pick up at least one DTV station, 99.35% US households get at least one digital channel, this represents over 95 million households.

US DTV broadcast towers in July 2003

Broadcasters have already begun the transition to HDTV. All of CBS’ and ABC’s prime time shows are broadcast in HDTV; this includes popular shows such as CSI and Survivor, as well as Alias and the NBA/NHL Finals. Many of NBC’s prime time shows are also broadcast in HDTV as well, examples include the The West Wing and Law and Order.

Kobe shooting a free throw

Looks like a pick and roll setup here

Miami skyline

Leno in Hi-Def

Another shot from Leno last night

Note the difference in this 480i signal

DTV 101

In order to understand how DTV compares to HDTV it’s important to know the basics. The conventional analog television we watch today is only capable of displaying up to 480 vertical lines of information in an interlaced format, meaning that every other line is drawn per frame on the screen and thus reducing the amount of data that needs to be generated. This is frequently referred too as 480i or standard definition television (SDTV) and would be the equivalent of 640x480 at 30Hz on your monitor. The next step up is 480p (640x480 at 60Hz) with the “p” denoting progressive scan. 480p delivers the same 480 lines, only all of the lines are drawn every frame. This is considered DVD-level quality and produces a flicker-free image where text or fast motion video is used.

Formats compared

A single interlaced frame

A single progressive frame

HDTV goes one level beyond DTV, whereas conventional DTV is limited to just 480 lines, HDTV offers two formats: 720p and 1080i. As its name implies, 720p is a progressive scan format, delivering 720 vertical lines for a base resolution of 1280x720 at 60Hz. In comparison, 1080i is interlaced, but delivers more lines, 1920 horizontal, 1080 vertical (1920x1080 at 30Hz).

Besides improved video quality, DTV and HDTV also provide six-channel 5.1 digital audio, while many HDTV programs are broadcast in a 16:9 format with Dolby Digital audio, just like going to the movies (SDTV programming may be either). DTV broadcasters can also send multiple digital channels with the same frequency (multicasting): this allows TV stations to broadcast multiple programs at once, weather or traffic information can be sent, or additional programming information is provided. In fact, the local PBS station here in Austin provides four different channels, while ABC and NBC both offer secondary weather channels.

Weather reports on minor channels

Bad weather incoming

The biggest limitation to DTV has been its cost. Manufacturers still charge a pretty hefty premium for HD-capable television sets, even cable and satellite providers get in on the action. ATI has decided to tap into this growing market by providing a low-cost alternative capable of displaying crystal clear images on your PC. After all, most monitors are more than capable of driving HD resolutions. Their solution? The ATI HDTV WONDER.