Station Information

In Depth: All About Digital TV and HDTV

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Click the links below to visit various parts of this page, and find answers to your questions about the new world of digital television and HDTV.

  • What is Digital Television or DTV?
  • How is my current television different from DTVs?
  • Do I need a new television set to watch WABC-TV's HDTV broadcasts?
  • Where can I find WABC-TV's digital channels, and where can I watch in HD?
  • Is HDTV replacing standard television?
  • Are digital televisions compatible with my existing video equipment?

  • What is the difference between HDTV, EDTV, and SDTV?
  • What are the different display technologies used in Digital Televisions?
  • How is a HDTV/EDTV/SDTV different from a HDTV/EDTV/SDTV Monitor?
  • What are the benefits of a Digital Television?
  • Are digital broadcasts available now?

  • What are the 18 formats of ATSC standard?
  • What are Vertical Scan Lines?
  • What are Horizontal Pixels
  • What is Aspect Ratio?
  • What do you mean by Scan Mode?
  • What is Frame Rate?

  • Do I need component inputs or RGB inputs for my DTV?
  • Can I connect a DTV to my PC or Laptop?
  • What does "down-convert" mean?
  • What does "up-convert" mean?
  • What will the future of digital television look like?
  • *Return to the WABC-TV -HDTV Index

    What is Digital Television or DTV?

    Digital TVs are television sets that can receive and display digital television broadcasts sent using any one of eighteen digital signaling methods. Consumer Electronics Association (CEA) classifies digital televisions in three broad categories: HDTV (High Definition TV), EDTV (Enhanced Digital TV), and SDTV (Standard Definition TV). Top of page

    How is my current television different from a DTV?

    The TV you watch today is based on an analog system developed over 50 years ago. Due to the analog nature of the system, it is likely that your current TV was designed to receive analog signals only. You can receive and display digital broadcasts on your existing analog TV by connecting a digital-to-analog converter box; however, the picture quality is compromised by the display limitations of the analog technology inside your TV. Top of page

    What is the difference between HDTV, EDTV, and SDTV?

    HDTV, EDTV, and SDTV reference the ability of a digital television to display various digital TV pictures. Digital TV broadcasts can be transmitted using any one of eighteen resolution-formats (see chart below); however, digital televisions differ in their ability to redisplay the image, especially when a high-definition image is received.

    HDTVs can receive all 18 formats and re-display high-definition images using 540 lines (1080 lines interlaced) or 720 lines (progressive scanning method) without down converting.

    EDTVs can receive all 18 formats including high-definition broadcasts and all 18 formats are re-displayed at 480 lines using progressive scan method. This method reduces flicker; however, picture quality may not necessarily outperform 480 interlaced when viewed at normal viewing distances.

    SDTVs can receive all 18 formats including high-definition broadcasts and all 18 formats are re-displayed at 480 lines using interlacing (same resolution as current analog TVs). This means that high-definition broadcasts are down-converted in order to display the image at 480 lines. Top of page

    Do I need a new television set to watch HDTV?

    Although HDTV is available over the air using a standard antenna or via digital cable or satellite, you must have a high-definition tuner and monitor to properly decode HDTV signals and display them accurately. WABC-TV's programs are also broadcast in standard format, so there are no programs that are ONLY for HDTV. Your regular television set simply ignores HDTV signals that are being broadcast. Still, the quality of your picture will be dramatically better whether or not you have an high definition television set. Top of page

    Is HDTV replacing standard television?

    Not immediately. WABC-TV and other broadcasters will continue to offer programs in the standard format for at least the next several years. By February 2009, every TV station in the U.S. will be required by law to "switch off" their analog or traditional television signals and begin broadcasting only in digital format. WABC-TV is ahead of the game and taking it one step further by going high-def. Top of page

    How do I get Eyewitness News and WABC-TV programs on digital TV and in HD?

    You can watch our digital signal and our HD programming either over the air, via digital cable or via satellite. If you want to receive WABC-DT over-the-air, here is our free, digital channel lineup:

  • 7-0: WABC-TV
  • 7-1: WABC-HD (High Definition)
  • 7-2: WABC Plus
  • 7-3: WABC Eyewitness News Now

    Over the air viewers: If you are using either a set-top receiver or a digital TV with a built-in ATSC/8VSB receiver, your set should identify WABC-TV's News Channel as "7-2", or one channel above WABC-DT's High Definition TV channel 7-1. In some cases, you may need to either tune your receiver to Channel 45 (the actual broadcast channel used by WABC-DT), or have your set automatically search for new channels, for your receiver to locate and remember how to tune into 7-2.

    Tuning in Via Cable

    Time Warner

  • 7-1: Channel 707
  • 7-2: Channel 164
  • 7-3 Channel 163

    Comcast

  • 7-2 Channel 231 (NJ)
  • 7-2 Channel 232 (CT)
  • 7-3 Channel 246

    RCN:

  • 7-1 Channel 185 .
  • 7-2 Not Carried Currently

    Cablevision

  • 7-1 Channel 707
  • 7-2 Channel 107 (NY and NJ)
  • 7-2 Channel 114 (CT)
  • 7-3 Channel 108 (NY and NJ)
  • 7-3 Channel 117 (CT) Top of page

    What are the 18 formats of ATSC standard?

    There are 18 digital television formats prescribed by the Advanced Televisions Systems Committee. Six are considered HDTV formats (1080p, 1080i, and 720p). Each format has a different combination of screen resolution, scan mode, frame rate, and aspect ratio requirements.

    Format

    Vertical Scan Lines

    Horizontal Pixels

    Aspect Ratio

    Scan Mode

    Frame Rate (fps)

    1080p

    1080

    1920

    16:9

    Progressive

    24

    1080p

    1080

    1920

    16:9

    Progressive

    30

    1080i

    1080

    1920

    16:9

    Interlaced

    30

    720p

    720

    1280

    16:9

    Progressive

    24

    720p

    720

    1280

    16:9

    Progressive

    30

    720p

    720

    1280

    16:9

    Progressive

    60

    480p

    480

    704

    16:9

    Progressive

    24

    480p

    480

    704

    16:9

    Progressive

    30

    480p

    480

    704

    16:9

    Progressive

    60

    480p

    480

    704

    4:3

    Progressive

    24

    480p

    480

    704

    4:3

    Progressive

    30

    480p

    480

    704

    4:3

    Progressive

    60

    480p

    480

    640

    4:3

    Progressive

    24

    480p

    480

    640

    4:3

    Progressive

    30

    480p

    480

    640

    4:3

    Progressive

    60

    480i

    480

    704

    16:9

    Interlaced

    30

    480i

    480

    704

    4:3

    Interlaced

    30

    480i

    480

    640

    4:3

    Interlaced

    30

    Top of page

    Vertical Scan Lines

    Vertical scan lines refer to the number of horizontal lines a television can display to create an image. As the number of lines increase, more information is displayed, resulting in better picture quality. Traditional analog TVs can display approximately 480 lines, while high-definition television can display up to 1080 lines. Top of page

    Horizontal Pixels

    Each horizontal line in a TV is made up of individual dots (pixels). The higher the number of pixels, the finer the TV picture becomes. Horizontal pixel measurements using today's technology can range from 250 for a VCR to as much as 500 for a DVD player. Typical digital TV broadcasts have at least 640 pixels. Top of page

    Aspect Ratio

    Aspect ratio identifies the ratio of the TV screen's width over its height. A 16:9 aspect ratio refers to a wide-screen picture format, while a 4:3 refers to a standard TV format. Top of page

    Scan Mode

    Interlaced scanning is a method that creates a TV picture with alternating lines of information and is the cause for flickering. Progressive scanning is a method that creates a TV picture with consecutive lines of information that results in flicker-free picture quality. Top of page

    Frame Rate

    Motion picture on your TV is generated by a series of still pictures that changes from picture to picture at a very fast rate. This rate is measured by the number of still pictures (frames) displayed within one second of time. The higher the frame-rate, the smoother the picture displayed. Top of page

    What are the different display technologies used in Digital Televisions?

    Digital televisions use the same display technologies available today for analog TVs and computer monitors. They include CRT (Cathode Ray Tubes), LCD (Liquid Crystal Displays), front and rear projection, and PDP (Plasma Display Panels). Most digital TVs today use CRT and projection technologies; however, the CRT maintains an advantage over projection technologies with a wider viewing angle that makes it more suitable for living room viewing. Top of page

    How is a HDTV/EDTV/SDTV different from a HDTV/EDTV/SDTV Monitor?

    In order to receive digital broadcasts, a digital decoder must be used to receive and decode digital broadcast signals. Digital decoders can be built into the digital television itself or they may come in the form of a set-top box that is added separately to the television. HDTV/EDTV/SDTV Monitors are digital televisions without a digital decoder built into the television. HDTV/EDTV/SDTV Monitors give you the flexibility to add a digital decoder in the future when digital broadcasts are more prevalent. Top of page

    What are the benefits of a Digital Television?

    The primary benefits of digital televisions are superior picture quality and better sound. The analog TV signals we watch today are made of 525 interlaced lines and are subject to screen flickering, ghost-shadows, and blurring. Digital televisions are dramatically different in that they receive signals digitally in the form of 0s and 1s so problems with ghost-shadows and blurring go away. Digital signals also produce a higher quality TV picture, displaying crisp, sharp and vivid images using up to 1080 lines instead of 525 lines. Additionally, digital television signals can deliver cinema-quality sound effects using 6-channel Dolby Digital surround sound instead of only two regular stereo channels. Top of page

    Are digital broadcasts available now?

    Digital broadcasts are available through terrestrial (antenna), satellite, and in the near future, cable systems. Major television networks such as ABC, have already begun broadcasting digital TV programming. Top of page

    Do I need component inputs or RGB inputs for my DTV?

    RGB inputs and component inputs are the best connectivity interface for use with todays high-resolution digital sources such as DVD players (standard or progressive) and HDTV decoder set-top boxes. RGB and component inputs work with video signals that are split into its base components, resulting in a cleaner and purer video signal than all other connection options. There are two types of component inputs and Sampo HDTV Monitors/TVs are equipped with both. The standard component inputs can accept 480i signals while the high-definition component inputs can handle 480i, 480p, 720p, and 1080i signals from progressive DVD players and HDTV decoder set-top boxes. Top of page

    Can I connect a DTV to my PC or Laptop?

    Yes, as long as the digital television is equipped with an RGB input (15-pin D-sub connector). A digital television is essentially a high quality computer monitor capable of displaying various resolutions from today's advanced video cards. All Sampo HDTV Monitors/TVs are equipped with an RGB-output that lets you connect multiple monitors in series for multimedia presentation purposes. Top of page

    What does "down-convert" mean?

    Down-convert takes place when a digital broadcast signal exceeds the display capabilities of the digital television and the broadcast signal is reduced to match the television's limited display capabilities. For example, if NBC broadcasts a digital program using 1080 lines (1080i format) while the digital television is only able to display 480 lines (480i or 480p), the 1080i signal is reduced or down-converted to only 480 lines, resulting in inferior picture quality. Sampo HDTV Monitors/TVs can display all digital resolutions from 480 lines to high-definition 1080 lines, eliminating the need for the HDTV decoder to down-convert broadcast signals. Top of page

    What does "up-convert" mean?

    Up-convert takes place when a digital television's display capabilities exceed the digital broadcast signal and the broadcast signal is increased to match the TV's display program using 480 lines (480i or 480p) and the digital television is able to display 1080 lines, the signal is increased or up-converted to match the TV, resulting in hazy picture quality. Sampo HDTV Monitors/TVs can display all digital resolutions from 480 lines to high-definition 1080 lines, eliminating the need for the HDTV decoder to up-convert broadcast signals. Top of page

    Are digital televisions compatible with my existing video equipment?

    Most digital televisions are compatible with your existing video equipment; however, this depends on the types of connectivity options available on the digital TV. All Sampo HDTV Monitors/TVs are equipped with multiple connection options for connections with your existing video equipment including VCRs, DVD players, Progressive DVD players, LaserDisc/VideoCD Players, analog and digital camcorders, Digital VHS players, and video game machines. Top of page

    What will the future of digital television look like?

    The broad bandwidth of the new digital television system facilitates a whole new spectrum of programming and data services for your home. For example, this bandwidth allows at least 4 standard-definition TV broadcasts to simultaneously display on your digital TV screen, in addition to displaying data content such as news, stock reports, email, and other data related services. In the near future, your digital television will become an information resource hosting multiple broadcasts in multiple windows while displaying data content in banner strips. Top of page

    Where can I find out more?

  • FCC
  • National Association of Broadcasters
  • Consumer Electronics Association
  • The Advanced Television Systems Committee
  • Audio-Video Science Forum
  • This information available from http://www.110220volts.com.