Digital TV : Computer Hardware Buyers’ Glossary

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Digital TV
aka DTV, Digital Television: A new digital broadcast format for television, both via the air and via cable. The ATSC (Advanced Television Systems Committee) devised the American digital TV standards for resolutions from 704×480 (DTV) to 1920×1080 (HDTV 1080p).
Advantages of DTV Old Style CRT TVs
Display Technology DVR
Monitor vs Digital TV Real World Equipment
HDTV cables and Connectors Bandwidth
Cost Links

Advantages of DTV

The USA is switching on 2009-02-17 from analog NTSC to digital and dropping analog. Your analog VCR will stop working too. Thereafter you will need to buy a analog to digital converter to make your current TV work. The current VHF channels will be recycled for things like cell-phones, Internet transmissions, pagers etc. However, most cable and satellite services will continue to offer the old analog connection. In Canada, Shaw cable will continue to offer analog service until about 2011.

We will see gigantic hard disks replacing the VCR. This should bring down the cost of hard disks for computer users.

The catch is, the programming content is the same old same old you got on analog TV; it is just prettier.

Display Technologies

There are four types of display technology:
  1. CRT

    cathode rate tube. Old style. Consumes a lot of AC power and produces a lot of heat.
  2. LCD

    liquid Crystal display: sharp, low power, limited viewing angle.
  3. gas plasma

    bright, high contrast, more expensive than LCD. Uses more power.
  4. OLED

    Organic Light Emitting Diode, latest out the lab, vibrant colours, from Sony, obscenely expensive.

Monitor vs Digital TV

An LCD monitor looks very much like a digital TV. However there are some differences.

HDTV cables and Connectors

An HDTV might have a variety of possible inputs including:
HDBC connector HDMI (digital, latest and greatest). The signal is the output of a tuner, a single video channel (with theatre sound channels), uncompressed. It uses a 19-pin connector that looks at first glance similar to a USB connector. Digital means noise-free. These cables cost $50.00 CAD to $150.00 CAD so check if they are included and factor them into the cost of your new TV.
coax connector Digital coax cable from the cable/satellite company. At a casual glance these look like RCA phone jack cables. Read the label. These cables cost $25.00 USD to $100.00 USD
6-pin Firewire connector IEEE 1394 (Firewire), so you can hook up your Mac. There are 4 and 6 pin versions and three speeds 1394a, 1394b and 1394c. The 6-pin type are most commonly used in HDTV. Apple collects royalties on every Firewire port in the universe. This is mainly why they are more expensive than USB ports. These cables cost $6.00 USD to $35.00 USD
DVI-D connector DVI-D (older digital scheme).
component A/V connector Component Video (analog). Uses colour difference, not simple RGB. Connectors are labelled [Y R B] (yellow red blue) or [Y, R-Y, B-Y] (yellow, red minus yellow, blue minus yellow) or [Y, Cr, Cb] or [Y, Pr, Pb]. That handles the video. In addition you have two more cables for left and right audio. These cables cost $30.00 USD to $105.00 USD
S-Video connector S-Video (analog HDTV, low quality). The signal is the output of a tuner, a single channel, decompressed, analog. It uses a 4-pin mini DIN connector. It separates out brightness and colour signals.
vga analog PC connector PC VGA, analog, so you can hook up your computer. 15 pins, often with pin 9, a keying pin missing. That handles the video. In addition you have two more cables for left and right audio. These cables cost $7.00 USD to $30.00 USD
SP/DIF PC audio digital optical connector PC Audio, so you can hook up your computer. This could be a variety of connectors including mini plugs, RCA phono jacks, S/PDIF digital 5.1 (front left/right, back left/right, woofer) optical fibre or S/PDIF coax. You may need to buy adapter cables to convert. S/PDIF optical is shown.
composite A/V connector A/V (Composite) analog legacy, aka yellow RCA connector. You will get an old-style analog NTSC picture. These look a lot like digital coax. Make sure you read the label when you buy cables.
Above images are not shown to the same scale.

Cost

When you double the size of a screen, you have four times as many pixels. In the manufacturing process it is much more difficult to manufacture a large screen than a small one with no defects. If four small screens have one defect among them, the manufacturer discards one screen and sells three. If a big screen, the equivalent in size to four small screens, has a defect, the manufacturer discards the big screen and has nothing to sell. That is partly why large screen TVs are so much more expensive than smaller ones.

The cost of a new HDTV can really add up, because you will also be strongly tempted to buy:

Before you buy a TV, note the model number and check it out on the Internet. You should be able to find detailed specs, comparative prices, diagrams of the connectors, and even the manual.

Old Style CRT TVs

Be careful because retailers often don’t tell you a new TV is actually a CRT (Cathode Ray Tube). They hope you will be fooled and imagine it is an LCD flat panel because they advertised it as flat panel. One giveaway is the weight. A CRT will be a whopping 40 kg for a 27” CRT TV. CRT TVs are not desirable, unless you rarely turn them on, since they use so much electricity. Oddly, even though they are much heavier, they are cheaper. CRTs come in three flavours: round, virtual flat and true flat.
round TV Tube type virtual flat TV Tube type true flat TV Tube type
Round televisions have a rounded picture tube, with a rounded cabinet. This gives the television a bubble effect. Virtual Flat televisions have a rounded picture tube, with a flat frontal cabinet. This gives the television and picture a flat effect (but is still a rounded tube) True Flat televisions have a flat tube and flat cabinet giving a true flat picture effect.

Digital Video Recorder

A DVR (Digital Video Recorder), sometimes called a TiVo (though that is actually a brand name of a premium quality DVR) is a small computer with a hard drive that can record television shows on a hard disk. It is the digital equivalent of the VCR. Unlike a VCR, it can record only so many hours before it is full and you have to erase something to make room for more. There is no cartridge that you can replace to give it infinite capacity. Though it would seem to me, it should be relatively easy for DVR makers to add a DVD burner so you can export recorded shows. It can also do instant replay in slow motion, or full speed. It can instantly jump to anything previously recorded, unlike a VCR which must slew tape. I was astounded to learn there is no proper protocol for the DVR to control the cable company’s channel changer box, unless you buy your DVR from the cable company. The DVR works in a rinky dink, unreliable way by pretending to be an infrared remote control. DVRs are usually much cleverer than VCRs. You can, for example, tell them to record episodes of House that you do not already have recorded, without telling it when to record or which channel. It automaticaly consults the computerised TV listings to discover when it is on.

Real World Equipment

Amazon is a fun place to “window shop” since they tend to have a fair bit of technical information about the various models. You can search sorting by price, which is a way to sort out what various features cost you. The following links are to high end equipment. High end models tend to have the best explanations of what the various features buy you. Further, you can Google the model numbers to find even more information from the manufacturer and online reviews all over the web. From there you can find more reasonably priced items.

Check the native resolution. If it is not 1920×1080 or higher, your screen will not do full HDTV. It may display the image, but not in full detail. Only the largest TVs offer 1920×1080. Most offer 1366×768, 3/4 the full resolution.

Digital TV Equipment
HDTV Component Standard Digital TV
Amazon product imagerecommend Amazon⇒LG Plasma HDTV
Bright plasma display. It is 71" wide. It has 1920 x 1080 resolution, full HDTV 1080p. Does not contain a tuner. The cable company set top box must provide channel selection logic. Has two HDMI connections.
American flag amazon.com.
Plasma TV
Amazon product imagerecommend Amazon⇒Panasonic Plasma Digital TV
It is 50" wide. It has 1366 × 768 resolution, not up to full 1080p HDTV snuff. S-Video, 9 and 15 pin VGA. RGB component video in. HDMI is an optional accessory.
American flag amazon.com.
Amazon product imagerecommend Amazon⇒Samsung Series 4 PN58A650 Plasma HDTV
I like Samsung. They make solid no-nonsense gear that does not break down, and that gives good value for the money. This model is 58" wide. It has 1920 × 1080 resolution, full HDTV 1080p. 100,000 to 1 contrast ratio (bigger is better).
American flag amazon.com.
Plasma TV
Amazon product imagerecommend Amazon⇒Samsung PN42A450 Plasma Digital TV
I like Samsung. They make solid no-nonsense gear that does not break down, and that gives good value for the money. This model is 42" wide. It has 1365×768 resolution. 100,000 to 1 contrast ratio (bigger is better).
American flag amazon.com.
Amazon product imagerecommend Amazon⇒Sharp Aquos LCD HDTV
This is the biggest LCD TV you can buy, and of course, the most expensive. It is 65" wide. It has 1920 × 1080 resolution, full HDTV 1080p. Has a CableCard slot for the cable company to insert its electronics. Has component, S-Video, DVI, Firewire and HDMI inputs.
American flag amazon.com.
LCD TV
Amazon product imagerecommend Amazon⇒Toshiba LCD Digital TV
It is 32" wide. It has 1366 × 768 resolution, not up to full 1080p HDTV snuff. DVI input.
American flag amazon.com.
Amazon product imagerecommend Amazon⇒Samsung Series 7 LN52A750 LCD HDTV
I like Samsung. They make solid no-nonsense gear that does not break down, and that gives good value for the money. This model is 52" wide. It has 1920 × 1080 resolution, full HDTV 1080p. 50,000 to 1 contrast ratio (bigger is better). 4 ms response time (smaller is better). 4 × HDMI inputs.
American flag amazon.com.
LCD TV
Amazon product imagerecommend Amazon⇒Samsung Series 6 LN22A650 LCD HDTV
I like Samsung. They make solid no-nonsense gear that does not break down, and that gives good value for the money. It is 22" wide. It has 1280×720 resolution. 50,000 to 1 contrast ratio (bigger is better). 4 ms response time (smaller is better). 4 × HDMI inputs.
American flag amazon.com.
Amazon product imagerecommend Amazon⇒TiVo Digital Recorder
Magnetic tape-style VCRs will not longer work with digital TV. Instead you use a digital recorder. This one from TiVo will record your favourite programs for you without you having to explicitly tell it when they are on since it consults an online TV guide it accesses via a telephone call. Further it will let you pause and rewind a show you are watching live. It can record 180 hours digitally. Can record a basic and digital channel simultaneously, but not two digital channels. Some TVs come bundled with a digital recorder.
American flag amazon.com.
Digital Recorder
Amazon product imagerecommend Amazon⇒TiVo Digital Recorder
Magnetic tape-style VCRs will not longer work with digital TV. Instead you use a digital recorder. This one from TiVo will record your favourite programs for you without you having to explicitly tell it when they are on since it consults an online TV guide it accesses via a telephone call. Further it will let you pause and rewind a show you are watching live. It can record 80 hours digitally. Some TVs come bundled with a digital recorder.
American flag amazon.com.
Amazon product imagerecommend Amazon⇒Sony Blu-Ray DVD player
You can no longer rent movies to play on magnetic tape-style VCRs with digital TV. Instead you use a DVD player. Ordinary DVD players cannot provide the full HDTV resolution. This one can, when it plays the new Blu-Ray discs, at 1080p. Some TVs come bundled with a DVD player, as do home theatre speaker systems. Make sure it is HDTV-Blu-Ray capable. HDMI output.
American flag amazon.com.
HD-DVD player
Amazon product imagerecommend Amazon⇒Toshiba DVD/DivX Player
This can play ordinary and DivX DVDs, often used for ordinary resolution movie rentals. This player provides inputs to a digital TV, or a HDTV, but it cannot read the high res HD-DVD or Blu-Ray DVDs. Output S-video.
American flag amazon.com.
Amazon product imagerecommend Amazon⇒Sony Blu-Ray Player
You can no longer rent movies to play on magnetic tape-style VCRs with digital TV. Instead you use a DVD player. Ordinary DVD players cannot provide the full HDTV resolution. Blu-Ray is an ultra high capacity disk that can display full 1080p. It is not clear whether HD-DVD or Blu-Ray DVD will become the standard for rented HDTV movies. I suspect HD-DVD will win out, but if Blu-Ray wins out, you will need this DVD Player. HDMI output.
American flag amazon.com.
Blu-Ray DVD player There is no point in an expensive Blu-Ray DVD player with ordinary DTV.
Amazon product imagerecommend Amazon⇒Samsung DVD Home Theater System
This is a high end six-speaker system, front pair, back pair, center, subwoofer, 1000 watts, optionally wireless, bundled with an HD-DVD.
American flag amazon.com.
home theatre surround speaker system
Amazon product imagerecommend Amazon⇒Audiovox DVD Home Theater System
This is a six-speaker system, front pair, back pair, center, subwoofer, 200 watts, bundled with an an ordinary DVD that cannot read HD-DVD or Blu-Ray.
American flag amazon.com.
Amazon product imagerecommend Amazon⇒Haupauge HTDV tuner card
This is a cheap way to get HTDV. Fits inside your computer. Uses your computer monitor and computer speakers. It has 1920 × 1080 resolution, 1080i not full HDTV 1080p. It can connect to an over-the-air antenna or a S-Video connection to a cable box. If you buy a tuner make sure it accepts suitable inputs. The catches:
  • You can’t use your computer while people are watching TV.
  • The screen likely won’t be all that big.
  • The viewing angle on your screen will be narrower than for a true TV.
  • You need to hook your computer up to your stereo to get decent sound.
American flag amazon.com.
Computer HDTV Tuner card Nobody makes pure DTV tuner cards, either they are HDTV/DTV or analog.

Bandwidth

To support digital TV and HDTV takes considerable extra bandwidth, even with compression, since the HDTV image has (1920×1080) / (648×486) = 6.6 times as many pixels per frame (though full 1080p would rarely be delivered via cable and never by air broadcast). In addition, the cable or broadcaster might provide three or more versions of the program: analog, digital and HDTV. Where does all the extra bandwidth come from? The HDTV versions could not be broadcast in the same VHF frequency band as the original analog TV station. It must be carved out of new UHF bandwidth. On cable, the carrier can be creative with agile frequency assignments, assigning frequencies dynamically as needed for the various combinations of programming. This is transparent to the TV. HDTV always appears to it an a fixed channel/frequency, usually in the 200s. For a station that broadcasts sometimes in HDTV and sometimes in normal resolution, all the programs will appear on the HDTV channel. There would be a second channel that always broadcasts in regular resolution. There is no automatic channel hopping when an HDTV show comes on.

Besides the air, cable, satellite, and DVD rentas you can also downoad programming over the Internet sometimes free and sometimes for a fee.

Stages

Here are the stages in evolving TV. The longer you stall to adopt the new technology, the lower the prices will drop.
  1. Analog. Problem with interference on some channels, with mild to severe degradation of picture and sound.
  2. Digital box with analog TV. Removes interference introduced in the cable system. Still has minor interference on the cable from the box to the TV.
  3. Digital box with digital TV. Removes all interference. You can still get complete loss of picture with a weak signal, but you won’t get snow.
  4. HD box with HD TV. No interference. Large clear picture, at least for shows broadcast in HDTV and for HD DVDs.
  5. HD box with record function and HD TV. Ability to record shows while you watch another one. Ability to pause shows you are watching live, or replay.
  6. HD Box with record function and HD TV and theatre speaker system. Theatre-like surround sound.

Unfortunately, the more channels there are the lower the quality of each channel. There is a fixed advertising budget spread over more and more channels. The future Internet based on fibre will allow each channel to have world wide distribution. This should cause the total number of channels to drop, and hence for quality of each channel to rise again, along with tens of thousands of amateur, low-budget and niche channels, some of which will be available on a subscription basis.

ATSC Standards
Bell Expressvu: Canadian HDTV satellite provider
Converting an analog TV for digital over-the-air reception
DirecTV: American HDTV satellite provider
Dish Network: American HDTV satellite provider
DVD
DVI
HDMI
HDTV in the USA
HDTV overview
Motorola set top boxes: typical of HDTV tuners you buy/rent from the cable company. Shaw.ca uses the DCT1616
Rogers.com: Canadian HDTV cable provider
S-Video
Shaw.ca: Canadian HDTV cable provider
Star Choice: Canadian HDTV satellite provider

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