News and Reviews....

HDTV ..... As I See It    October 2001

By Bob Lieto

It has been quite some time since I first heard the acronym HDTV or Digital TV as it was called in the beginning, sometime in 1986 as I recall. The foreign markets tried to dictate to us the use of their scheme (MUSE), which was in place  in Asia and Europe. It was an analog process which expounded upon our NTSC system. Our Government wanted a new process, one that would spur a new growth in the industry. The plan was to have it developed, up and running by 1992. That time schedule never came to bear fruit.

By 1993 the FCC stepped up to form the GRAND ALLIANCE of manufacturers, developers and a who's  who in the industry and asked them to come up with a "STANDARD". The result took us to about 1995-6, and that result was roughly 18 variations on a standard, listed for all manufactures to follow. Follow .... ?????

Once the dust cleared and we understood more about the complexity and differences of the "standard", we began to sort out what parts of the standard we really needed to keep and what was repetitious by virtue of each manufacturer's pride in becoming incorporated into the "standard". Keep in mind there were different electronic schemes of encode and decode in providing the signal as well. It finally boiled down to about eight (8) variations which get us from 480P to 1080i picture quality.

Now what does 480P stand for you ask. Well it means the total (picture) signal is send to the receiver in four hundred and eighty lines in Progressive format. This basically means the picture is displayed in whole frames, one on top of another as oppose to "Interlaced" where the picture is displayed in two frames that are scanned, first the even lines and then the odd lines. Extrapolate the term of "interlace" to 1080i and you understand the picture is made up of one thousand, eighty lines of information in an interlaced format. To cover the variations in the standard, manufacturers decided to make the sets either upgradeable or sell a box which could serve as the upgradeable piece of the puzzle.

To understand picture quality, let us compare 1080i to something we know in today's terms. Our system of today is the NTSC standard, an analog interlaced picture capable of a maximum 525 lines of which 483 are visible. The average analog cable system provides about 200 -330 lines of information. The average VCR provides about 240 lines of information. The average VHS-VCR provides about 400 lines of information and the average DVD provides about 500 lines of information. So you can see that 1080 lines of anything is going to be twice as good (more resolution) as the best picture we have available today.

Let me get back to our topic of HDTV. So the industry still sees variations and is trying to make its TV sets upgradeable, but the problem is that one manufacture upgrade scheme is not the same as the other. And so, if you purchase, lets say a upgradeable Mitsubishi TV, and find that the RCA set top converter box is better or has an unique feature which is desirable, you may not be able to get connectivity between the two. Add to this the Hollywood factor. Hollywood movie makers are afraid that movies are going to be copied in digital form, which is almost perfect from one copy to another. And so, they are supporting not one, but two different scrambling schemes. The TV set purchased to receive and decode one format, might not be able to produce the second. This zest to protect may have rendered most HDTV-ready monitors today (2001) and ones sold within the last two years, as not being ready for HDTV at all.

Custom Audio-Video Systems strives to be on the cutting edge of information for our clients. We design our systems to be as flexible as can be foreseen. We do not sell our equipment stockpiled from our warehouse, most system designs are completed and orders filled on an as needed basis. This accomplishes two things for our client, (1) they are assured that the products sold to them are going to work together and, (2) they are not sold product that "needs to be moved" due to inventory. This "as needed" scheme also falls in line with the way our projects progress from design through installation. All pieces are provided as the installation process dictates.

We will be writing more on the HDTV progression into the industry. As we all know the NTSC format is scheduled to be discontinued in 2006, with all stations having DTV replications of their analog signals on air by December 31, 2004. So be it.

Added September 2003 - The NTSC shutdown has been extended to year 2007. This extension is directly related to the pace at which the Television Networks have upgraded their "headends" or in other terms their output facilities.

Added June 2004 - The NTSC shutdown has been extended to year 2009 with probability to after 2010. This extension is directly related to the 85% factor. Where the change over and eliminating of the analog signal and channels we know today is based on 85% of the markets ability to receive over-the-air digital signals. As of today 84 million households have cable digital signals available, 9 million households have High Def Monitors, 1.2 million have over-the air HD Tuners, 1.4 million have cable HD tuners, and 600 thousand have DBS HD Tuners. A rush to eliminate the analog signals has lead to the FERREE FACTOR (Kenneth Ferree is chief of the FCC Media Bureau). What Mr. Feree wants is to calculate the 85% rule by requiring the cable companies to retransmit all local DTV channels in a down-converted analog format. Hence, if 85% of cable or satellite viewers in a market could see the DTV shows - even in lower resolution on today's analog TV monitors - the analog broadcast channels would go dark. Custom Audio-Video Systems will keep this page updated due to the importance we feel, to our clients, in understanding how the transition is progressing. 

Added November 2005 - The NTSC shutdown has been written into proposed law  to end on April 7 in the year 2009.

Added January 2006 - The NTSC shutdown has been written into law  to end on February 17 in the year 2009.

To get a listing of HDTV stations, by state available (on air) go to "http://www.fcc.gov/mb/video/files/dtvonair.html".