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Frequently asked questions about HDTV [Provided by TitanTV]

What do 1080i and 720p mean?
The most common high definition formats are: 720p and 1080i. The 720p format makes a picture with 720 vertical lines, each with 1280 pixels horizontally. It uses progressive scanning, like computers, which sends a complete picture 60 times per second. The 1080i format creates a picture with 1080 vertical lines, each with 1920 pixels horizontally. 1080i uses interlaced scanning, like traditional TV, which alternates sending odd lines and even lines and thus sends a complete picture 30 times per second. Both formats make for a clearer, sharper picture than analog television.

What is 1080p?
1080p resolution is a fairly new format that is 1080 lines of progressively scanned video. A television set’s inputs must be able to process a 1080p signal and be designed to accept 1080p/24/30/60 fps signal from an external 1080p progressive source.

What is the difference between Digital Television (DTV) and High Definition Television (HDTV)?
DTV is the umbrella term used to describe the new digital television system adopted by the FCC in December 1996. DTV is a new way of transmitting television signals. It will eventually replace analog, the way television has been transmitted for the last 50 years. HDTV uses the entire “channel” and offers superior picture and CD quality sound.

Is all digital programming in high definition?
No. Digital programming can either be in standard definition (SD) or high definition (HD). Standard definition broadcasts can have a format of either 480i or 480p. High definition broadcasts can be e720p, 1080i or 1080p format.

What are the advantages of High Definition Television?
The first noticeable difference of high definition TV from the analog television system is that the screen is much wider. With analog TV, the width of the picture is divided by the height of the picture and will always produce a 4/3 ratio. High definition television, on the other hand, has a width to height ratio of 16/9, which closely approximates that of a movie screen. The second advantage is that HD has over six times the sharpness and clarity of analog TV. The HDTV picture contains 1080 vertical picture elements (pixels) by 1920 horizontal pixels for a total of over 2.0 million pixels. The current standard definition picture contains only 480 vertical pixels by 720 pixels for a total of 345,600 pixels. Third, the color resolution of HDTV is also more than twice the resolution of analog. High definition television also has six channels of CD-quality surround sound (left, right, center, left rear, right rear, and low frequency effects).

How can I find out what programs are broadcast in High Definition?
TitanTV takes a member’s street address and predicts the digital over-the-air stations one can expect to receive. Programs available in high definition are marked with a red HD symbol in the program grid cell. In addition to providing listings and HD designation information for over-the-air channels, TitanTV also provides this information for digital cable and satellite lineups.

What do I need to start watching TV in HD?
First, you need a digital TV and a digital TV tuner. You can buy the tuner and display in an integrated DTV, with both built in. If you purchase a DTV monitor (an analog TV with the capability to display DTV) you will need to buy a DTV tuner in a separate set-top box. DTV tuners can be included in a DTV satellite receiver, a DTV capable digital cable box or an over-the-air DTV tuner.

Second, you must be able to receive a digital signal at your location. Depending on where you live, DTV signals can be delivered through digital cable, digital satellite or an over-the-air antenna that receives digital signals. TitanTV provides a comprehensive list of the digital channels available at your address. To receive a free over-the-air signal, you will need an over-the-air antenna. The type of antenna required depends on your location and distance from transmitters and local terrain. In many instances, a rooftop antenna will be most effective. To find out what antenna works for your home, use TitanTV’s antenna selector section.

Third, a program must originate in HDTV and be broadcast in HDTV. Just because you have an HDTV set and signal does not mean that everything you watch will be in High Definition. And just because a program arrives through a digital cable or a digital satellite does not mean it is in HD. Much of the programming today, even that received from a digital satellite, digital cable, or even a digital channel broadcast over the air, is delivered in what is known as standard definition. You will get a better picture than you would get with the analog broadcasts TV has used for all these years, because a digital picture will be free from the ghosts and snow that can plague analog transmissions. A standard definition digital picture will be good, but not nearly as sharp and crisp as HD.

What types of HD sets are there?
There are different types of high definition TV sets suited for various room layouts, budgets and priorities:

Flat-panel LCDs and plasma TVs offer space-savings but may be more expensive than other options.

Rear projection TVs offer large images at more affordable prices but may not fit in certain rooms given their size.

Front projectors offer the largest HD images but room brightness have adverse effects on the overall viewing experience.

Direct-view HDTV sets offer reliability of television picture tube technology but also can be fairly large in size.

What is the difference between LCD and Plasma TVs?
The foundation of the Plasma TVs is over a million tiny glass cells that are charged with a mixture of neon and xenon. Behind these cells are colored phosphors, which are chemical compounds that emit light when energized. Each cell has three phosphors; one red, one blue, and one green. When activated by an electrode, the plasma cells emit invisible UV light. The UV light strikes the red, green and blue phosphors on the back of the display and thus creates the pixels that form the image you see on the screen.

LCD (Liquid Crystal Display) technology works differently. Liquid is suspended between two transparent panels. Within the liquid are crystals that, when activated by voltage, re-position themselves so that they either allow the light to pass through the panel and/or block the light. This process is similar to turning on and off a million light bulbs. Fluorescent tubes behind the panels supply the light source. Both the lit and unlit crystals create visible pixels that cumulatively compose the image on the screen.

Is there a cut-off date by which broadcasters must be broadcasting in digital?
Yes. February 17, 2009, is the date that broadcasters must end transmitting their analog television signals.

What is multicasting?
A digital signal has the capability for up to19.4 Mbs of content—allowing a station to provide multiple Standard DTV channels in digital, a process called multicasting. This means that a station can transmit multiple channels in the same bandwidth instead of just one.

Why do digital stations sometimes have two channel numbers?
The FCC has assigned a digital or RF channel number to all digital stations. In addition, some local affiliates are using Program and System Information Protocol (PSIP) to remap to their analog channel numbers. PSIP is data that is transmitted along with a station’s DTV signal that tells DTV receivers important information about the station and what is being broadcast (what channel to tune to for reception of the station, helps maintain current (analog) channel number branding, tells receiver whether multiple programs are being broadcast, etc.).

How do I know if a station is multicasting?
TitanTV takes your street address and predicts what digital over-the-air stations you can expect to receive, including stations that are multicasting. TitanTV presents all sub-channels that a station has programming on. These stations are typically represented with a major channel and a minor channel (example: 54-1, 54-2, 54-3, etc.)

What types of information (programming) is typically multicast?
Local affiliates can broadcast any type of programming content on their sub-channels. Common programming that is available from stations that are multicasting include: weather radar, sports, re-broadcasts of local news, educational programming and much, much more.

Why do stations use their digital spectrum to multicast?
Many broadcast stations choose to multicast programming like Weather and Traffic. This gives viewers more programming content (for free, over-the-air) and broadcasters more advertising opportunities. Some stations choose to multicast all of the time in addition to their high definition broadcast.

What is datacasting?
Datacasting is the use of digital television bitstreams to send data packets in place of television. An 8-VSB terrestrial broadcast signal sends up to 19.4 Mbps of data directly to the receiver. A standard DTV program requires only 4-5 Mbps of data for DVD quality television. This leaves about 15 Mbps of unassigned bandwidth available 24 hours a day, 7 days a week from 8-VSB broadcast stations. Datacasting provides data at high speed, utilizing wireless transmission in point-to-multipoint (one message sent through a network multiple times for each user) mode rather than the Internet’s point-to-point transmission. Point-to-multipoint allows all recipients to receive the signal at its highest quality.

What stations are datacasting?
Datacasting is still a fairly new component to digital television and many stations do not have immediate plans for datacasting. The opportunities and technology continue to be researched with public television stations the primary datacasters at this time.

Why would a broadcaster choose to datacast?
Broadcasters may choose to use their digital spectrum to broadcast additional information and content of their own or they may choose to ‘rent’ their spectrum to other datacasters to generate additional revenue.

How can I as a consumer benefit from datacasting?
Datacasting provides consumers with the opportunity to receive additional content such as video, music, games and many other options.

Glossary of HD Terms

 

16:9: Ratio of the dimension (also know as aspect ratio) of a widescreen TV. While the typical analog TVs have square screens, newer TVs look like movie theater screens. DVDs and high definition broadcast are formatted for the 16:9 ratio.
4:3: Ratio of the dimensions of a traditional TV set. This shape is suitable for TV broadcasts but is not wide enough for big-screen movies. To show these on a traditional TV, the movies have to be edited (trimmed by 25 percent) or be shown in letterbox format which involved blacking out a strip at the top and bottom of the TV screen.
8-VSB: The transmission standard for digital TV in the US, endorsed by the Federal Communications Commission in 2001. The letters indicate that it is the number 8 mode of vestigial sideband modulation. All receivers made in the US are 8-VSB compatible.
NTSC: National Television Standards Committee or the body that originally developed the black and white, and subsequently color television system that has been in use for over 50 years in the US and elsewhere.
ATSC: Advanced Television Systems Committee or the group that formed in 1993 and offers technical guidelines on how digital television should be broadcast.
Aspect Ratio: The proportion of a TV screen’s width to its height. Most TVs are either 4:3 or 16:9.
Active Scan Lines: The tiny rows of pixels on a television screen. There are 480 lines on a typical analog NTSC TV screen and 1,080 on an HD set.
CableCARD: A device supplied by a cable company that slides into a set-top box or television. The card identifies the user account and turns off protection safeguards to HDTV channels can be viewed.
Plug-and-play or digital cable ready: A DTV or other device for digital cable customers that plugs directly into the cable jack and does not require a separate set-top box. Plug-and-play TV owners must obtain a CableCARD from their cable company in order to view scrambled programming services.
HDTV (high definition TV): A TV set with a built-in tuner that can show HD broadcasts in true HD resolution. Also refers to the broadcasts themselves. According to the Consumer Electronics Association, a fully integrated TV set will receive all ATSC terrestrial digital transmissions and decode all ATSC Table 3 video formats. It must display active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i) or higher in a 16:9 widescreen aspect ratio. It must also receive and decode or pass-through for decoding Dolby® Digital audio. It must also receive and decode or pass through for decoding 5.1 digital surround sound.
Standard Definition Television: Digital broadcast that has 480 active scan lines (like traditional analog signals). The format does have clearer sound and a picture free of interference. According to the CEA, SDTV now refers to fully integrated television receivers that receive all ATSC terrestrial digital transmissions and decode all ATSC Table 3 video formats to produce a usable picture. It can have active vertical scanning lines less than EDTV quality. No aspect ratio is specified and it must receive some form of usable audio signal.
Letterbox: Format sometimes used to show wide-screen movies on traditionally shaped 4:3 TV sets. A letterboxed movie has black bars above and below the image.
Receiver: Device that tunes an analog or digital TV broadcast. A digital receiver, which also decodes the signal, can be built into the TV set or work as a part of another piece of hardware like a set-top box. A digital TV receiver pulls in frequencies from a TV antenna, satellite signal or cable connection.

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