Digital Cable - A service provided by many cable providers, digital cable offers viewers more channels. Contrary to many consumers' beliefs, digital cable is not the same as High-Definition Television or digital television; rather digital cable simply offers cable subscribers the options of paying for more services. Digital Monitor - DTV monitors are televisions that can display a digital signal but lack an integrated tuner (unlike an integrated digital set), and thus cannot receive a digital broadcast signal without an additional set-top box.
EDTV - (enhanced definition TV) - Essentially DVD quality, it is a small step up from NTSC. An EDTV will convert all 18 ATSC formats to 480p.
Convergence - An adjustment that must be made occasionally to CRT sets. This adjustment makes the three colors coincide perfectly.
8-VSB - Acronym for the transmission method used for over-the-air DTV broadcasting in Canada and the USA. Eight discreet amplitude level, "vestigial side-band" broadcast transmission technology. VSB is an analog modulation technique used to reduce the amount of spectrum needed to transmit information through cable TV, or terrestrial broadcasting.
VSB - " Vestigial side band." VSB is an analog modulation technique used to reduce the amount of spectrum needed to transmit information through cable TV, or over-the-air broadcasts.
Set-top box (STB) - A box, similar to the familiar cable box, that is capable of receiving, decoding and sending to the associated television the picture and sound of the selected DTV broadcast. The use of an STB would allow the use of conventional televisions to receive DTB programs, but at reduced levels of resolution and with imperfections due to aspect ratio differences, leading to letterboxing or cropping of the sides of the picture.
DirecTV - (see DBS)
Interlaced Scanning - Some HD televisions and most conventional televisions use the "interlace" method of scanning, in which the picture is transmitted and painted on the screen in two passes. In the first pass, every other line is painted and in the second, the lines in between. Some display types, such as LCD, plasma and DLP cannot display directly images transmitted as interlaced signals and must convert them to a progressive format prior to their display.
Digital Tuner - A digital tuner serves as the decoder required to receive and display digital broadcasts. It can be included inside TV sets or via a set-top box.
MTS - (Multi-channel Television Sound) - This refers to an analog NTSC TV equipped with stereo and SAP (separate audio program) features.
YPrPb - Color representation requires three independent variables. CRTs - prefer red, green, and blue. Ink jet printers prefer yellow, magenta, and cyan. NTSC encodes color as luminance (brightness), hue (color), and saturation (absence of white in colors). Storage media such as DVDs prefer Y, Pr, and Pb, where Y is luminance, Pr is Y-red, and Pb is Y-blue. This is because Pr and Pb can be at lower resolution and not degrade the image noticeably, thus saving storage space.
Pixel - A picture element; a single displayable video dot. HDTV requires from 1 to 2 million pixels in the display for full resolution images to be shown.
Composite Video - An analog video signal (NTSC, PAL or SECAM) that includes both luminance (brightness) and chrominance (color) signals encoded together to form a single signal.
Standard Definition TV Format (SDTV) - There are two main digital formats - HDTV and SDTV. SDTV typically does produce better quality images than that of traditional analog TV and pictures somewhat akin to digital cable. However, its images are not nearly as sharp as the images from the ultimate form of digital television _ High-definition TV (HDTV).
A/D - Electronic device that connects an analog television signal to a digital system.
HDTV - High Definition Television - HDTV is a TV system having approximately twice the vertical and horizontal picture resolution of today's NTSC TV and having a wide aspect ratio of 16 - 9. Two HDTV formats are currently in use; (a) 1920 pixels per line and 1080i lines per frame and (b) 1280 pixels per line and 720p lines per frame. HDTV can be recognised by its spectacular picture resolution, freedom from annoying artefacts and impressive 5.1 channel surround sound.
MPEG-2 - (Motion Picture Experts Group technical standard 2) - This is a widely used standard for digital encoding of motion pictures. It typically achieves a 50 to 1 compression of data. It achieves this mainly by not retransmitting areas of the screen that have not changed since the previous frame.
Dolby Digital 2.0 - This is a two channel (stereo or Pro Logic) version of Dolby Digital. It is often used by DBS systems.
Multicasting - The option to multicast was made possible by digital technology to allow each digital broadcast station to split its bit stream into 2, 3, 4 or more individual channels of programming and/or data services. (For example, on channel 7, you could watch 7-1, 7-2, 7-3 or 7-4.)
