I wrote this article originally for the HDTVetc journal for the August 2003 issue, and it was later published on the HDTV Journal in 2006. Consumers still go through the same struggle at national-chain stores today. I updated the article to include current HD equipment and technologies. Its tutorial substance and analysis are still applicable today, and are intended to help consumers in making the right purchasing decisions. Enjoy the reading.
The following topics are covered in this segment:
H/DTV and NTSC TV Systems, What are they?
The First Work of the DTV Transition
Quality HDTV, or Quantity DTV, or Both?
Backward Compatibility with Legacy Analog TV for Digital Broadcast
Satellite/Cable, and the DTV Transition
Tuner Integration
The Effect DVD had for DTV
The Rush for Knowledge
You have been hearing about HDTV and decided to start looking for one. A mate of yours reminds you that the general knowledge about purchasing regular TVs from the CRT analog period is not sufficient to select a digital product today, so you quickly review what you read about widescreen, black bars, digital tuners and resolution, and hope things would clear out at the store.
You get in to the typical nationwide consumer electronic store most people go to, and suddenly see several dozens of HDTV demo sets staring back at you. A salesperson is approaching you, the person’s face is familiar; the salesperson is the one that sold you the new dishwasher five weeks ago; now the person is selling HDTVs with authority. At that point you start feeling worried, but you hang in there.
Obviously this store is not a quality dedicated A/V retail place. Lots of consumers make their purchases based on the uninformed advice of untrained staff from typical nationwide consumer electronic chains.
In the near past, a typical store could only have one of those HDTVs actually displaying HD, the one that had an HD tuner; the rest were showing the same picture from a video distribution loop not suitable for HD quality.
Today perhaps the whole store feed is all HD, and the sets that are staring at you show the same picture, but with different colors, contrast, picture enhancements, blacks, whites, etc. because no one bothered to set them correctly. So you start wondering why HDTV is not consistently ideal as is being preached, is that what HDTV is about?
The salesperson turns toward you and, in the midst of your consumer panic assault, tells you: “trust me, buy this TV, it would look much better at home two times connected to an HD tuner”. Would you buy a automobile without test-driving it?
Millions of people went through similar experiences since HDTV was introduced in November 1998. Fortunately, some improvement is gradually seen in the stores, in dedicated A/V retail stores, which ought to take more time to help consumers understand the ideas behind each display know-how, and not quickly sell the HDTV stock with the red tags, as most national consumer electronic chains do.
Most consumers love red tag savings, and lots of leave the stores wallet-happy with a product they do not understand. Perhaps lots of of those do not actually require to understand because the HDTV know-how has been introduced with a complexity level they refuse to deal with to receive a TV.
To illustrate the complexity of an HDTV purchase decision you may require to read Is HDTV Complex ?
The aim of the article you are reading is to help you make your purchase with more confidence, but first let me cover the following basic subjects about HDTV:
H/DTV and NTSC TV Systems, What are they?
You might already know of the US plan to replace our current analog interlaced TV process (NTSC) dated from the 1940′s by a digital DTV process, by February 17, 2009. Curiously the idea started as “analog” HDTV until General Instruments proposed an all-digital process in 1990.
The DTV standard consists of 18 digital formats grouped in to five levels of quality, as approved by the ATSC (American Tv Systems Committee) in 1995:
1) SD: Standard Definition, with 480i/p (i:interlaced, p:progressive) viewable horizontal lines of vertical resolution (rows counted from top to bottom), each line with up to 704 total pixels of horizontal resolution (counted from left to right), and with a side ratio (relation of width to height in units) of 4×3 (as regular TV), or widescreen 16×9.
2) HD: High Definition, with 720p and 1080i/p viewable horizontal lines of vertical resolution (rows counted from top to bottom), each line with respectively 1280 (for 720p) or 1920 (for 1080i/p) total pixels of horizontal resolution (counted from left to right), and only in widescreen 16×9 aspect ratio.
Note that, because is not complex , the horizontal lines (rows) are expressed as “vertical” resolution (480, 720, 1080), and the vertical columns made of the aligned pixels on the horizontal lines are expressed as “horizontal” resolution (704, 1280, 1920).
DTV was 15 years in the making before it went on the air in November 1998. HDTV is the quality part of DTV, but its implementation is not mandatory, SD is. I will use the term DTV only when addressing the digital TV process in general.
Later in 2000, the Consumer Electronics Association (CEA), allegedly to help confused consumers, created another resolution level in between: ED (enhanced definition).
This promoted the 480p SD format to ED level, leaving only the 480i format in the SD level. It also granted any TV the right to be labelled HDTV if capable to display only 810i lines of vertical resolution within the displayed picture, than 1080i.
One can argue how much this intervention from the CEA helped consumers over helped manufacturers getting rid of mediocre sets. But that returned when CRT based DTV sets were the strength of the market; now most DTV sets are fixed pixel displays and their resolution is clearly specified as a pixel count in both directions.
Our current NTSC over-the-air (OTA) TV process is 480i analog interlaced (actually 525i with 480i viewable horizontal lines of vertical resolution). The regular channels of digital satellite and digital cable could be compared to digital SD of broadcast DTV, but they are also transmitting dozens of channels in HDTV.
To facilitate the transition, broadcasters got one additional channel slot from the FCC for the simultaneous broadcasting of the analog and digital versions of their programming. It is a gigantic investment for TV stations to build a DTV facility with new cameras, production, equipment, etc.
When DTV is fully implemented, broadcasters must return one of the five channels, analog over-the-air broadcasting will cease, and current analog TVs, VCRs, TiVos with analog tuners would cease “tuning” as well (but they will still work as display devices if fed with a 480i analog signal from a converter, VHS tape, DVD player, etc). This date was originally set for January 2007 but has been extended to February 17, 2009. Two times DTV is implemented, the FCC will auction that spectrum of airwaves.
Most OTA terrestrial TV stations are already broadcasting DTV in SD and HD widescreen, and consumers are purchasing HDTV sets at accelerated pace every year.
The First Work of the DTV Transition a glance back at CEA’s 2003 statistics, on the first 5 years of HDTV about 6 million DTVs (of which only 300,000 where integrated with DTV tuners) and 400,000 tuner set-top-boxes (STBs), were sold between 1999 and 2003. By the finish of 2007, the HDTV count was 8 times fold, and about 50% of households have digital TV sets, according to the CEA.
Back in 1998/9 it was not unusual for first generation HDTV monitors to cost $10,000, and HD STB tuners to cost from $700 to $3,000. It was expensive for early adopters.
By the finish of 2007, a gigantic variety in technologies and TV sets was obtainable for every viewing surroundings. DTV sets are much better in quality, and sell for a small fraction of the cost they sold back in 1998.
Quality HDTV, or Quantity DTV, or Both?
All of us love the brilliant video quality of HD, however, since HD is not mandated within the DTV plan, it allows a broadcasting station to make use of the allotted 6 MHz space (for the HD channel), to multicast in lieu several sub-channels of lower SD quality, as it is actually happening on lots of stations across the US.
When sharing the same 6MHz total bandwidth, SD sub-channels rob about 2-3 Mbps each from the needed bandwidth of an HD channel that by itself ought to broadcast at 19.4 Mbps (if the station also multicasts an HD sub-channel). The parallel broadcast forces further compression of the 19.4 Mbps HD signal to a lower bit rate to make room for the SD sub-channel, compromising HD quality.
In lots of cases, over one SD sub-channel is multicast together with the HD sub-channel. When the reduced HD bit rate compresses the signal beyond acceptable limits, it renders a lower quality picture with noticeable artifacts, on speedy moving images in sports, which are more evident, and unacceptable, on gigantic screens (more on it later).
It might even be feasible that the TV station desires to share some of the bandwidth for data-casting interactive services, or for mobile DTV applications for hand-held transportable devices (because there will be no analog broadcasting to those transportable devices as well). For more information, check the articles I wrote on the “Mobile DTV” series, where I analyze the potential impact of mobile applications on the quality of an HD channel when robbing from its bandwidth.
All of us hope that HD will reign, and HD quality will prevail over the digital-quantity business models, and you need to encourage DTV broadcasters to do so, besides, most consumers bought an HDTV not a SDTV.
Backward Compatibility with Legacy Analog TV for Digital Broadcast
When the DTV broadcast is fully implemented in February 17, 2009, there would be backward compatibility together with your current analog equipment, but there is a catch, in order for you to watch DTV terrestrial digital channels on your current analog TV you would need a digital over-the-air STB tuner connected to it. Your current analog TV would display an analog interlaced 480i version of the digital picture. There is no need to rush for the replacement of an analog TV that might be in nice working condition in case you require to continue watching similar quality TV, but you would need to buy a STB digital tuner for broadcast DTV.
This is applicable also to your analog VCR, DVD recorder, TiVo, etc., in case you require them to have broadcast tuning independence. A few years ago, DTV STB tuners were comparatively expensive, in the $400-$1000 cost range, imagine purchasing a $400 digital tuner for a $30 analog VCR, but they are gradually coming down in cost.
The US government has approved a subsidy coupon program to help people purchase DTV tuners to facilitate the analog-to-digital transition so existing analog TV sets can continue to be used for broadcast digital DTV.
For that purpose, Congress approved a fund of $1.5 billion dollars, with an preliminary allocation of $990 million dollars to subsidize up to five $40 coupons per household. The coupons became obtainable in January 2008 and can be requested by consumers until March 2009, to make use of them toward the acquisition of five DTV tuners.
The five coupons cannot be used together to buy one DTV tuner, neither they can be used to buy another type of OTA tuner/DVR STBs, satellite STBs with broadcast DTV tuners in to them, or cable STBs.
The tuners offered by this program are expected to cost in the $50-$70 range each; the consumer would must pay the difference after applying the $40 coupon. According to the plan, the tuners would become obtainable by mid February 2008 through the national chains of Best Buy, Circuit City, etc.
Although the subsidized tuners are designed to tune digital SD and HD channels, they cannot output the tuned signal other than 480i analog resolution to an analog TV. In other words, the subsidized tuners would not perform as typical HD tuners passing resolutions of 480p, 720p, or 1080i to HDTV devices for HD viewing. Their functionality is to downconvert because their purpose is backward compatibility to analog TVs, but their cost is lower than typical ATSC HDTV tuners with variable output resolutions and digital outputs.
Satellite/Cable, and the DTV Transition
In case you are a satellite subscriber you already have the satellite STB you need for their digital SD/HD services. Additionally, most satellite boxes also have a terrestrial ATSC tuner in case you require to get free local channels using a VHF/UHF antenna. However, DirecTV introduced a new model in late 2007 without antenna input; the local channels would must be viewed from the satellite feed, a service they have already for most major cities.
In case you are a cable subscriber, when the cable company decides to disable the analog feed to your household and supply only the digital feed, you would need a digital-to-analog cable STB to view the digital channels on each analog TV in your house, similar to the approach of the coupon program for broadcast DTV above, but you would need to lease or buy the cable STB, no coupons.
Cable companies were authorized by the FCC in late 2007 to continue their analog feed service for another 5 years (up to 2012) in the event that they prefer, but they are not obliged to do so. Cable STBs do not have DTV digital terrestrial tuners in to them so you cannot use their STB connected to a UHF/VHF antenna to get free local channels.
Cable companies face at least five options on the analog-to-digital transition between 2007 and 2012:
a) If their subscriber base is mostly digital, a cable company might have the incentive to make a gigantic up front investment to acquire digital STBs to convert all the remaining analog subscribers as soon as feasible to digital tier services, who would must lease one digital STB for each analog TV. That would release the bandwidth occupied by the analog broadcast channels on the cable feed, which could be used for additional digital channels, and get an increased revenue if those are premium, VOD, PPV, etc. paid services.
b) If the subscriber’s base is mostly analog, a cable company might prefer to keep the existing mix of analog and digital STBs, and maintain the analog tier as long as needed until 2012. Since the cable feed bandwidth allocation for the analog broadcast channels must continue with this alternative, the company would must postpone the potential growth of digital channels and services, but there won’t be a necessity for an up front gigantic investment for expensive digital STBs because there is no forced conversion. This option seems economical for both the company and the subscriber, because a subscriber would not be forced to lease a digital STB for each analog TVs that might be currently connected to the wall coax without a STB, as many non-primary TVs are in most households.
While the up front investment of a large number of digital STBs could be expensive to a cable company, there could be a partial offset with the potential revenue received from additional digital pay services such as VOD, PPV, or premium channels. Additionally, the number of digital STBs required for a full digital conversion of the cable feed might be further reduced when considering the growing base of integrated HDTVs with CableCARD tuners expected to increase in 2008 and 2009.
However, since the integrated CableCARD tuners within HDTV sets are only unidirectional, there might still be a cable subscriber’s base that would still require the bi-directional capabilities of cable HD-STBs for VOD, PPV, and cable supplied programming guide. Each cable company would have to balance those factors until 2012.
Tuner Integration
In 2002 the FCC issued a “mandatory” plan to gradually integrate digital broadcast tuners into DTV monitors and other tuning devices, such HD DVRs. The plan has been already implemented in 2007 for all the sets larger than 13″, and all DTVs on sale today are mandated to include digital terrestrial tuners (except for some industrial/professional models). In most cases they also include a cable on-the-clear tuner for non-premium unscrambled channels, or even include a CableCARD tuner for premium channels and services.
As mentioned above, the CableCARD tuners are unidirectional only, and lack the bi-directional features of Video-on-Demand, Impulse Pay-per-View, and cable-company supplied programming guide, for which a separate set-top-box from the cable company would still be needed until integrated TV sets are designed to have bi-directional capabilities on their integrated CableCARD tuners.
Industry analysts commented for years that economies of scale would bring down the price of digital tuners to the level of today’s very low price analog NTSC tuners within TVs, but the reality is that STBs for ATSC terrestrial, or for cable, satellite, DVRs, etc. (not the down-converting government-coupon STBs) still have a high price, considering that comparatively, large HDTVs came down from the $5,000-$10,000 in 98/99 to more accessible prices below $1000.
More on this subject is covered further down.
The Effect DVD had for DTV
Most of the 6 million people that bought HDTVs on the first 5 years of the transition (98-03) did so NOT to view HD, but rather to enjoy playing widescreen DVDs at 480p. Even now in 2008, after Hi-Def DVD has been already introduced in early 2006, regular DVDs are still a favorite content for DTV, because they certainly display quite well as progressive 480p, or upscaled to 720p or 1080i/p to the native resolution of the digital set (by either the DVD player or the TV set). The same DVD played on an analog TV would only show the image as a 480i interlaced scanning.
In addition, an HDTV has the capability to show widescreen DVDs in anamorphic format displaying all the original vertical resolution stored on the disc, while 4×3 analog TVs would show the same DVD letterboxing the image between larger top/bottom bars in order to maintain the wider aspect ratio of the movie, and with less vertical resolution for the image itself.
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