Advantages of DTV

• higher resolution, optionally including HDTV (High Definition Tele vision).

  Analog NTSC	DTV	HDTV 720p broadcast	HDTV 1080p DVD
  648×486	704×480	1280×720	1920×1080

• clearer picture since transmission static is automatically removed.
• more efficient use of bandwidth. Only as much is used as is needed for a given resolution.
• Theatre format 16×9 (aka widescreen or letterbox) rather than TV’s box format 4×3.

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

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

• A TV is about twice as bright so you can sit back.
• A monitor usually has more adjustments for position and angle.
• A monitor usually has higher resolution e.g. 1920 × 1200 pixels. An HDTV will have only 720p: 1280×720 progressive, 1080i: 1920×1080 interlaced(half speed) or 1080p: 1920×1080 progressive. SDTV (Standard DTV) will have only 480i: 704×480 interlaced or 480p: 704×480 progressive. In other words HDTV images are relatively wider but not as tall compared with monitors.
• A computer monitor will have an 15-pin analog connector, or four discrete analog cable, or sometimes a digital connection.
• The TV contains a tuner to filter out one channel out of many on a coax cable. A monitor can deal with only one signal on its input.
• Monitors typically update the screen 70 times a second. Progressive scan TV updates it 60 times a second, and interlaced 30 times a second. This makes monitors more immune to flickering in the presence of fluorescent light.
• Monitors are usually faster, with a response time of perhaps 6 ms (milliseconds) where a DTV might be 12 ms. The smaller the number, the crisper the picture during action shots.

HDTV cables and Connectors

	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.
	Digital coax cable from the cable/satellite company. At a casual glance these look like RCA phone jack cables. Read the label.
	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.
	DVI (older digital scheme).
	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.
	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.
	PC VGA, analog, so you can hook up your computer. 15 pins, often with pin 9, a keying pin missing.
	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.
	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

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

• An HD-capable DVD player. Your old DVD won’t do HD. Should you get a Blu-Ray or an HD-DVD? It is not clear which format will predominate in the video movie rental market. I suspect HD-DVD since the players cost half as much.
• An HD-capable digital recorder. You old analog VCR won’t work.
• HDTV cable or satellite service, or at least digital service. You will need a set top box which may cost more than the TV (or a TV with a built-in cable ready unit), and a DTV or HDTV cable subscription that costs perhaps 3 times what it does now. Because of the expense we may see computers and Internet video content (U-tube) competition growing explosively.
• You need some electronics called a tuner to extract the channel data feed from the broadcast signal containing all channels. It also decompresses the MPEG stream. Currently HDTV in North America uses MPEG-2, but there is a gradual switch to the denser MPEG-4. This tuner functionality might be inside the TV, a separate box, or something you rent or buy from your cable/satellite provider.
• Home theatre sound. The assumption is sound will be processed through your stereo system, and its speakers so you will need to have some sort of stereo system beside your TV. Home theatre 5.1 sound uses 6 speakers 3+2+1.
  • Front left, front centre and front right (3).
  • Rear left and rear right surround sound (2).
  • Center woofer LFE (low-frequency effects channel) (1).
  There are even more advanced schemes with up to 14 channels, but you won’t see these in digital TV, at least for now.

Old Style CRT TVs

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

Real World Equipment

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
recommend 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. amazon.com	Plasma TV	recommend 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. amazon.com
recommend 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. amazon.com	LCD TV	recommend Amazon⇒Toshiba LCD Digital TV It is 32" wide. It has 1366 × 768 resolution, not up to full 1080p HDTV snuff. DVI input. amazon.com
recommend 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. amazon.com	Digital Recorder	recommend 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. amazon.com
recommend Amazon⇒Toshiba HD-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 HD-DVD discs, at 1080p. It in 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 also need a Blu-Rray DVD Player. Some TVs come bundled with a DVD player, as do home theatre speaker systems. Make sure it is HDTV capable. HDMI output. amazon.com	HD-DVD player	recommend 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. amazon.com
recommend 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. amazon.com	Blu-Ray DVD player	There is no point in an expensive Blu-Ray DVD player with ordinary DTV.
recommend 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. amazon.com	home theatre surround speaker system	recommend 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. amazon.com
recommend 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. amazon.com	Computer HDTV Tuner card	Nobody makes pure DTV tuner cards, either they are HDTV/DTV or analog.

Bandwidth

Stages

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.