There has never been a better time to be a boob. (As in, the person addicted to the boob tube.) That’s because digital technology has elevated the TV medium to a much higher level of quality. (The picture quality, not the programming quality, unless you watch The Sopranos 24 hours a day.) Here are some of the byproducts of the digital revolution.
High Definition Digital Television
HDTV has been in R&D since the early 1980s. But it had been originally planned as an analog format and therefore of only marginal improvement over current sets. High-speed digital technology has allowed some dramatic improvements in television. In fact, the changeover from the analog NTSC format, to the digital ATSC format will be one of the most auspicious transitions in U.S. history, akin perhaps to the transition from the telegraph to the telephone!
All of the nation’s TV stations are scheduled to convert over to digital broadcasting within the next 18 months. And current analog TV signals are scheduled to terminate by 2006. This date will most likely not be met since the FCC will require that 85% of U.S. sets be able to receive a digital signal by this time, and that probably won’t happen. Even if current analog signals go away, present TVs will not be instantly obsolete because there will be a digital-to-analog set top box that will convert any digital signal to one that present-day sets can use. And those boxes will probably sell for cheap (like $100 or so).
“So what does digital television mean to moi?” you might ask. Well, a few things really. First of all, digital TV will offer two basic types of pictures: high definition (HDTV) and standard definition (SDTV). A high definition picture is characterized by a vertical resolution of 720 pixels per square inch or greater. The two main HDTV specifications are 720 and 1080. SDTV is characterized by less than 720 pixels, and will mostly feature 480 pixels per square inch. A 1080 HDTV picture is about 6 times higher resolution than today’s best-quality TV picture garners through a satellite or DVD player. Even the 480 SDTV picture is still about 35% better. Another major difference between digital and analog TV is the use of progressive scanning. Analog TV uses interlace scanning-every other “line” on the set is produced 30 times per second and these are interlaced together so fast that the eye perceives just one picture being produced. progressive scanning produces all of the lines all of the time. Computers use progressive scanning because it reduces flutter and works better for text and still graphics. The current analog bandwidth doesn’t allow for progressive scanning, but the digital bandwidth does. You can tell which type of signal is being produced by the letter that follows the number of pixels. HDTV is characterized by 1080i (Interlace) and 720p (Progressive). SDTV uses 480p or 480i.
If you find this difficult to follow thus far, you’ll be horrified to know that there are actually 18 different ATSC formats! But don’t be too scared-all digital TV sets will automatically detect the format and deliver a picture-you won’t have to do a thing, and you probably won’t even know about it.
Why are there so many? Simply because the digital bandwidth allows each station to broadcast either one HDTV signal, or up to five SDTV signals. And it is unclear which format the stations will choose. One thought is that prime-time movies and sports will be in HD, while daytime soaps and the evening news will be in SD. But your guess is as good as ours at this point, so we’ll have to take a look back in a year from now and see what happens.
Other exciting attributes of digital television are data simulcasting and Dolby Digital surround sound. Because the digital broadcast spectrum can accommodate so much data, you will be able to receive additional information about the show that you are watching, as well as some ability to be interactive. It is unclear yet how this will be used, but suffice it to say that you will be able to access synopses about the show before you decide to dedicate your evening to watching it.
Also, all digital television signals will boast the latest Dolby Digital surround sound-whether they are in HD or in SD. This is the current sound available on DVDs and through many DIRECTV satellite broadcasts. Since sound makes up half of the TV experience, any HDTV without an accompanying surround sound set up will be half-naked!
The final attribute of digital television is its aspect ratio. A 35mm film has different proportions than a TV set-it is wider and shorter. This ratio is called 16:9, whereas a TV set boasts a 4:3 ratio. Presently, most movies that are converted to video lose some picture around the sides. That is why when you rent a video, it says at the beginning that the picture has been modified to fit your TV set. True digital TV uses a 16:9 ratio-also referred to as “letterbox.” So if you are in the process of designing a new wall unit, make sure that your carpenter is aware of this change so you can fit the latest TV.