Dictionary of Video and Television Technology Newnes is an imprint of Elsevier Science Copyright © 2002, Elsevier Science (USA) All rights reserved [This page intentionally left blank.] No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher Recognizing the importance of preserving what has been written, Elsevier Science prints its books on acid-free paper whenever possible Library of Congress Cataloging-in-Publication Data ISBN: 1-878707-99-X British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library The publisher offers special discounts on bulk orders of this book For information, please contact: Manager of Special Sales Elsevier Science 225 Wildwood Avenue Woburn, MA 01801-2041 Tel: 781-904-2500 Fax: 781-904-2620 For information on all Newnes publications available, contact our World Wide Web home page at: http://www.newnespress.com 10 Printed in the United States of America Dictionary of Video and Television Technology Keith Jack Vladimir Tsatsulin An imprint of Elsevier Science Amsterdam San Diego Boston London N e w Yo r k San Francisco Singapore Oxford Sydney Paris To k y o [This is a blank page.] CONTENTS Preface vii About the Authors ix # A B 22 C 39 D 75 E 100 F 113 G 129 H 135 I 146 J 159 K 161 L 164 M 176 N 193 O 199 P 205 Q 224 R 227 S 239 T 271 v U 289 V 292 W 311 X 316 Y 317 Z 319 APPENDIX A: Associations 321 APPENDIX B: Standards Organizations 325 vi PREFACE Just a few short years ago, the applications for video were fairly confined— analog broadcast and cable television, analog VCRs, analog settop boxes with limited functionality, and simple analog video capture for PCs Since that time, a tremendous and rapid conversion to digital video has taken place, with consequent changes in broadcast standards and technologies “Convergence” is the buzzword that has come to mean this rapid coming together of various technologies that were previously unrelated Today we have: • DVD and SuperVCD players and recorders, with entire movies being stored on one disc, with newer designs supporting progressive scan capability for even higher video quality • Digital VCRs and camcorders, that store digital audio and video on tape • Digital settop boxes, which interface the television to the digital cable, satellite, or broadcast system Many also now support interactivity, datacasting, sophisticated graphics, and internet access • Digital televisions, which receive and display digital TV broadcasts, either via cable, satellite, or over-the-air Both standard-definition (SDTV) and high-definition (HDTV) versions are available • Game consoles, with high-definition graphics and powerful processing, and with the newer systems supporting DVD playback and internet access vii • Video editing on the PC, using real-time MPEG decoding, fast MPEG encoding, and other powerful techniques • Digital transmission of content for broadcast, cable and satellite systems, with the conversion to HDTV underway This is a complex and ever-changing field and there is a need for a reference that documents the evolving terminology, standards, and acronyms The Dictionary of Video and Television Technology contains the most up-todate terms and their usage The book is a valuable reference for engineers working in the fields of analog and digital video, broadcast personnel, technicians, or anyone charged with the task of understanding, using, or implementing video and television signals We hope this companion volume to the popular Video Demystified, 3rd Edition proves just as valuable to those creating and working with the converging technologies of the 21st century viii ABOUT THE AUTHORS Keith Jack has architected and introduced to market over 25 multimedia ICs for the PC and consumer markets Currently director of product marketing for Sigma Designs, Inc., he is working on next-generation digital video and audio solutions He has a BSEE from Tri-State University in Angola, Indiana, and holds two patents for video processing Vladimir Tsatsulin is a retired military officer with an electronics engineering degree from MVIZRU Military Academy Following his retirement from the military, he worked as a TV technology professor at “Elektrons” state company in Riga, Latvia and later was a member of the expert group that developed a TV and PC database for the Invention Machine Co Today Tsatsulin is a technical writer and translator for the Belorussian State University of Informatics and Electronics in Minsk, Belarus He is co-author of The English-Russian Dictionary on Television and Audio/Video Equipment, a standard reference now in its third edition ix [This is a blank page.] Weber’s law ing and improving it so that it sounds more realistic TV receivers with wave resonance try to emulate large, full sound within the limited, available space of their cabinets Weber’s law The visibility of an object in an image depends on the brightness contrast between different areas As in the case with most physical sensations, the magnitude of this perception tends to be proportional to the brightness ratio rather than to the absolute brightness difference This is expressed in Weber’s law: The increase in stimulus necessary to produce an increase in sensation of any of our senses is not an absolute quantity but depends on the proportion that the increase bears to the immediately preceding stimulus The perception of contrast between two areas also depends on the sharpness of the boundary If the boundary is sharp, a much smaller brightness difference can be perceived WebTV Microsoft trademark for set-top boxes used for interactive and regular TV Lets users access the Internet via connections to a standard TV and a phone line Supports WebPIP, which lets users simultaneously view web pages and TV programming on the same screen The WebTV service is now called the MSN TV service wedge A convergent pattern of equally spaced black and white stripes (usually from three to seven, on a gray background), that vary in repetition pitch so as to give the appearance of a wedge Used in a TV test pattern to indicate resolution Syn.: wedge mire wedge mire See Wedge weighting noise, audio component Human hearing is not equally sensitive to all frequencies This is especially true for low-level sounds, such as those in the background noise of audio systems Our ears are much more sensitive to midfrequencies than to ultra-low and ultra-high tones It follows, then, that noise delivered by a component only at the frequency extremes would be less bothersome than an equal amount of noise at midfrequencies delivered by another component Because of this, a system of measurement known as weighting has been developed, that attempts to measure signal/noise ratios in terms of their subjective effect upon the listener This system employs a specific filter so that low and high frequency noise makes less of a contribution to the final signal/noise readings than midfrequency noise If you see a specification preceded by the notation “A-weighted,” this method of measurement was used wh White whip Syn.: zip pan See also Swish pan white The mixture of red, green and blue in color TV white balance Refers to the amount of color that can be seen on a neutral object when the white balance controls on a video camera are adjusted for optimum White balance is measured in IRE: the lower the IRE number, the better the color purity A perfect white balance would measure zero IRE Adjustments for white balance are necessary when using a color video camera so that all color and light values register as true as possible Some cameras have automatic controls and meters Others have flashing warning lights and a hue control dial that is rotated until the appropriate white balance has been reached white balance control A feature on a video camera to help set or define colors by matching the white balance of the camera exactly to prevailing light conditions There are different kinds of controls for this purpose Red/blue controls are convenient but ineffective with green Independent red and blue controls can affect green by being turned all the way up (reducing green) or down (increasing green) Some cameras provide two tint dials: one for red and blue and one to balance green and magenta These controls are operated either automatically, by meters, by indicator lights, by click-stop positions, etc There are various ways to control white balance One approach is to factory-preset the red-green-blue signals to tungsten light and place color conversion filters behind the camera lens A switch then determines indoor/outdoor position (one filter) or, in some cases, indoor/hazy/sunny (two filters) Another technique for white balance control is to factory-preset average lighting condition such as tungsten, hazy light and bright sunlight The proper level is then set electrically by a switch For more flexibility, a red/ blue knob is added to change the relative balance of red and blue in the picture The knob controls red at one end of its turn and blue at the other The effects can be witnessed on a color monitor or on cameras with a meter Expensive cameras feature Automatic white balance, while others provide three controls: a switch to choose a filter or an electronic setting; then auto white balance is set; finally, the manual red/blue knob is used to check or override the white balance white balance hold A video camera feature that, when engaged, “sees” a white object and locks the unit into this position to maintain proper color as long as lighting conditions remain the same whiteboard An electronic device on which text can be written and one or more copies printed using optical sensors The material can be transmitted over telephone lines and viewed on a TV set, so that a whiteboard can be part of a teleconference white clip After emphasis, the positive-going spikes (overshoot) of the video signal might be too large for safe FM modulation A white-clip circuit is used to cut these spikes off, at an adjustable level See Dark clip white clip level extension Part of the high-quality (HQ) circuitry of particular VCRs The white clip level phase of the circuit is designed to provide sharper 312 wide screen signaling edges and a more distinct contrast between light and dark portions of the picture white compression (or white crushing) In TV, reduction of the gain at signal levels corresponding to white compared with the gain at black and midgrey levels The effect of white compression is to reduce the visibility of detail in highlight areas of the reproduced image Also called white saturation white crushing A form of peak distortion in the TV image resulting from amplitude nonlinearity, affecting the higher amplitude portions of the video signal Since the signals corresponding to white are at the peak of the waveform, they are often the first part to be distorted They usually distort to a greater degree than signals corresponding to other tonal values, with the possible exception of signals at or near black The nonlinearity causes the video signal to be compressed, so that the tonal values no longer have the same range The resulting compression on the TV screen is a loss of detail in the whites of the picture If the amplitude distortion is severe, the white compression becomes white clipping, showing as a complete loss of tonal detail in the white parts of the picture white field brightness The upper limit of the TV transfer function (S-shaped curve) It is usually established by the limitations of the display device, ordinarily a kinescope white flag See Multiburst waveform — NTSC VITS white level (US: reference white level) TV signal level representing full peak excursion above or below the sync level, according to whether modulation is positive or negative It represents a peak-white object This level defines what white is for the particular video system In black and white TV, the maximum permitted level of the picture signal (or, in color TV, of the luminance component) white level set White set A camera control that establishes the luminance level for a color camera white light Light that is comparable in wavelength content to average noon sunlight white object An object that reflects all wavelengths of light with substantially equal high efficiencies and considerable diffusion white peak (US) A peak excursion of the picture signal in the white direction Syn.: peak white, picture white white peak carrier Part of a carrier wavelength that holds the luminance signal When the white peak carrier is increased, the amount of space available for recording video detail on tape is expanded This contributes to the number of horizontal lines of resolution, which, in some cases, may be raised to 400 lines or more white peaking circuit Advanced circuitry used on some TV monitor/receivers designed to produce a purer white on screen This is accomplished by reducing the red beam of the electron gun and amplifying the blue beam whiter-than-white An excursion of the TV waveform signal above the normal peak (white) level white saturation White compression white set See White level set white uniformity On inferior TV sets, white objects on the screen may not always appear as white as they should White objects farthest from the screen’s center may display as gray A 100 IRE white field is used to measure how consistently whites are reproduced on the set without any gray areas or areas of color contamination whiz Syn.: zip pan wholesale politics Chiefly American Electoral campaigning via the media, especially TV, rather than by the politician’s traditional methods of addressing meeting, canvassing, etc Wide Area Network (WAN) A data network typically extending a LAN outside the building, over telephone common carrier lines to link to other LANs in remote buildings in possibly remote cities A WAN typically uses common-carrier lines A LAN doesn’t WANs typically run over leased phone lines—from one analog phone line to T1 (1.544 Mbps) The jump between a LAN and a WAN is made through a device called a bridge or a router wide-angle lens An optical lens with a very short focal length; a lens that has a large angular field (angle of view), generally greater than 80 degrees wideband Broadband Refers to a channel wider in bandwidth than a voice-grade channel Denoting an electronic device or circuit, such as an amp, that operates satisfactorily over a large range of input signal frequencies wideband axis The direction of the phasor that represents the fine chrominance primary (the I signal) in NTSC color TV; it has a bandwidth from to 1.5 MHz wideband switch Switch capable of handling channels wider in bandwidth than voice-grade lines Radio and TV switches are examples of wideband switches wideband video amplifier An electronic circuit, often found in TV monitor/receivers, designed to capture and reproduce the entire range of an incoming video signal The wideband video amplifier boosts the video signal by rasing its frequency response, which affects the horizontal resolution TV monitor/ receivers equipped with this active circuitry often attain 800 lines or more of horizontal resolution wide open Descriptive of a lens set at its lowest f-stop rating so that the iris is opened as wide as possible widescreen Viewed picture format with aspect ratio higher than in conventional TV and full screen occupation—e.g., 16:9 This is the aspect ratio used by HDTV wide screen signaling (WSS) Method of transmission of information about aspect ratio and some other parameters towards the TV receiver by data 313 width inserted in the vertical blanking interval Data embedded in the video signal containing information on the image aspect ratio and its position, on helper signal presence, on the position of the subtitles and on the camera/film mode selection In 625-lines systems—e.g., in the PALplus system—WSS data are transmitted during first half of TV line 23 WSS may be used on (B, D, G, H, I) PAL line 23 and (M) NTSC lines 20 and 283 to specify the aspect ratio of the program and other information 16:9 TVs may use this information to allow displaying of the program in the correct aspect ratio ITU-R BT.1119, ETSI EN300294 and IEC 61880 specify the WSS signal for PAL and NTSC systems EIAJ CPX-1204 also specifies another WSS signal for NTSC systems width The horizontal dimension of a TV picture The time duration of a pulse width control In TV receivers, the control that determines the amplitude of horizontal deflection and hence the width of the displayed picture The control is often a variable inductor connected in series with the line deflection coils In stereo sound reproduction, a control that determines the apparent width of the sound source It is often a variable resistor bridging the two channels and, in the zeroresistance position, parallels them so that the sound appears to originate from a point source located midway between the two loudspeakers wild footage Audio tape recorded out of sync with any particular video picture for use in post-production as an audio track; video tape recorded without audio for use as visual material in post-production to which narration will be added wind The manner in which magnetic tape is wound onto a reel In an A wind, the coated surface faces the hub In a B wind, the coated surface faces away from the hub wind noise switch A camcorder feature that helps to minimize some types of unwanted extraneous audio interference that may reach the built-in microphone window Test pattern in a form of a white box on a black or gray background A change of window size provides an easy way to control the average picture level A mode of test pattern generation where the main test signal is gated by a window signal to provide a gray or black background at the main test perimeter In 3D-TV systems, the position of a reference frontal place See also Depth matrix window dub A copy of a videotape that contains a box in the lower third of the tape that displays the time code on the tape Window dubs are generally only used when logging tape and during the offline edit windowing The videotape slippage that sometimes results from a loosely wound spool; also called clinching window mode [of HDTV down conversion] Mode of HDTV down conversion where the output TV pic- ture is produced from part of an HDTV source picture with on-line control of its size and position Syn.: zoom mode window of correction The maximum amount of time base error a time base corrector (TBC) can correct, measured in video lines A TBC with a four-line window might be fine for VTRs and tapes that never leave the climate-controlled confines of a studio, but it would be almost useless with tape that is shot in the field A TBC with a 32-line window costs a good deal more money, but it should be able to handle anything shot in the studio or the field Windows CE Microsoft Windows CE is a 32-bit realtime embedded operating system (RTOS) designed from the ground up to empower the development of a new range of emerging computing appliances, including set-top boxes, digital versatile disc (DVD) drives, entertainment consoles, smart phones, highly portable and personal computing devices like handheld computers, and home appliances Windows CE is modular, allowing use of a minimum set of software components needed to support receiver requirements This uses less memory and improves operating system performance Windows CE provides a subset of the Win32 application program interface (API) set, which provides an effective amount of application source-code level portability and compatibility and user interface consistency with other Microsoft Windows operating systems and Windows applications Windows Media Player Leading digital media platform for PCs that delivers the most popular streaming and local audio and video formats, including ASF, WAV, AVI, MPEG, QuickTime, and more Windows Media Player can play anything from low-bandwidth audio to full-screen video wind screen Similar to a pop filter; a heavy foam rubber cover for a microphone, used outdoors to diminish wind noise, etc wipe A special effect in which one image replaces another by means of a predetermined pattern In video, hundreds of different wipes can be produced by using a professional device called a mix/effects switcher Two of the more popular wipes are the rotary wipe and matrix wipe wire broadcasting The distribution of sound and/or TV programs to a number of receivers over a wired distribution system using audio frequencies or modulated carrier frequencies wired city A city or area with a high level of fiber optic networks and Internet services; popular slang in U.S for a city that is attuned to the latest in telecommunications and information technology wireless cable A TV service in which a TV signal is received from a satellite and retransmitted to a viewer’s rooftop antenna on a superhigh-frequency microwave channel See Multichannel Multipoint Distribution Service (MMDS) 314 WYSIWYG Wireless Cable Association (WCA) An organization of cable operators who use microwave transmitters, as opposed to coaxial cable, to broadcast cable programming to subscribers Wireless cable service requires a microwave antenna and an addressable receiver/descrambler See Multipoint distribution service wireless camcorder microphone A short-range, lowpower FM transmitter Consists of three main sections: the microphone element, the audio amp, and the RF oscillator The best receiver for the wireless camcorder microphone is a good-quality (sensitive) Walkman-type FM receiver because it is portable and lightweight The only requirement for the receiver is that it must have a headphone jack wireless infrared See Remote control wireless remote control See Remote control wireless video sender A device (transmitter and receiver) to extend cable, TV and VCR signals throughout a house Wollaston prism In a laser-type videodisc player, an optical component through which the laser passes before reaching the disc surface It then returns in polarized form word graphics The titles, credits, announcements or other word messages that appear superimposed on the TV screen Word graphics may crawl vertically up or down on the screen or move horizontally across the bottom, announcing news flashes, election returns and so on without interrupting program content Word graphics are usually white or light-colored against a dark background, often created by means of a technique called “keying.” word register See Digital image superimposer World Administrative Radio Conference (WARC) The ITU meetings that work out standards for international radio communications (including satellite TV) World Standard Teletext (WST) A British-developed teletext system Based on the successful experiences with both the Oracle and Ceefax one-way teletext operations in the UK, WST has been aggressively promoted as the standard for all teletext systems See also Electra World System Teletext See WST World Wide Web Another name for the Internet, used loosely Actually refers to the entire constellation of resources that can be accessed via Gopher, FTP, HTTP, telnet, USENET, and other tools, plus the universe of hypertext servers (HTTP servers) that allows graphics, text, sound files, video files, etc., to be mixed together WORM Write once, read many times Refers to the type of storage devices that can be written to only once, but read many times In other words, once the data is written, it cannot be erased Being optical, WORMs provide very high recording densities and are removable, making them useful for archiving wow Refers to tape speed variations that result in the distortion of the audio signal Wraase A family of amateur SSTV transmission modes first introduced with Wraase SC-1 scan converter developed by Volker Wraase, DL2RZ, of Wraase Electronic, Germany wraparound controls In videotex, a set of rules that govern what happens when the active position attempts to move off the defined display area wrap-around theater sound Surround sound writing speed The effective speed at which videotape moves past the recording heads in relation to the tape travel speed On VHS and VCRs, the video heads rotate at 1800 rpm while the linear tape speed is (3.34 cm or 1.32" per second in SP Therefore, the effective writing speed equals 230 ips for VHS See also Transverse recording WSS Wide screen signaling WST World Standard Teletext; World System Teletext Based on the British teletext standard in which a one-to-one correspondence exists between transmitted characters, page memory, word addresses and the display screen character locations Over 98% of the world’s TT decoders are WST compatible WTBS A superstation transmitted by satellite, offering baseball, basketball, professional wrestling, movies, TV reruns and some original shows WTBS, owned by Ted Turner, was the first superstation in the US It began operations in 1976 and offers programming 24 hours a day W-VHS Compatible analog HDTV recording system, JVC The system is available in Japan for recording and playback of standard, widescreen, and HDTV signals www See World Wide Web WYSIWYG Stands for “what you see is what you get” but screens don’t always work that way in reality Refers to the accuracy of a screen display in showing how the final result will look—for example, how a brochure will appear in it’s final printed form 315 X X Frequency band 8-12 GHz No one under 17 admitted; see Movie rating systems X-1 The original Beta tape speed, providing 60 minutes of recording and playing time on an L-500 videocassette Today, Beta I is reserved for professional and industrial machines XGA Extended Graphics Array Computer graphics display standard introduced by IBM in 1990 XGA-2 offers 800 x 600 pixel resolution in true color (16 million colors) and 1024 x 768 resolution in 65,536 colors x-ray television A closed-circuit television system replaces photographic film during X-ray inspection of welded joints and other industrial X-ray applications The technique gives instant images, without the time and cost of developing film It can show enlargements of as much as 50x, for detecting small defects For permanent records, a VTR can be added, or the images on the TV screen can be photographed selectively The TV monitor can be located remotely from the inspection area, so personnel are protected from harmful x-ray radiation XSVCD Abbreviation for eXtended Super VideoCD See Super VideoCD XVCD Abbreviation for eXtended VideoCD See VideoCD 316 Y Y Yellow In NTSC, PAL, SECAM and component video, the luminance signal, so named because it is the Y-axis of the chart of the spectral sensitivity of the human visual system In HDMAC, YL and YH are the low- and high-frequency components of the luminance signal Y adapter A connecting audio cable that is used to join two lines into a single input or output The Y adapter can be applied to many tasks, such as copying a stereo tape onto a mono VCR Using the stereo recorder as the playback machine, the owner connects the Y adapter from the two audio channel outputs of the stereo to the single audio input of the mono VCR It comes with various plugs or jacks Also known as Y connector or Y splitter Yagi aerial A sharply directional aerial array from which most aerials used for TV have been developed The active part of the aerial consists of one or two dipole aerials together with a parallel reflector and a set of parallel directors The directors are relatively closely spaced, being from 0.15 to 0.25 of a wavelength apart When the aerial is used for transmission, the directors absorb energy from the back lobe of the dipole radiation pattern and re-reflect it in the forward direction; the major lobe is thus reinforced at the expense of the back lobe When used for reception the inverse process occurs, causing the signal to be focused on the dipole yaw A term borrowed from aeronautics to describe the effective static rotation of the aircraft about an imaginary vertical pin Thus, the aircraft can be moving forward but not necessarily facing forward, offset by the yaw angle In digital video effects, this term can be used to describe the positioning of the effect (rotation about the Y axis) Y/C Y equals the luminance portion and C equals the chrominance portions of the video signal A Y/C piece of equipment or system will keep the components separate as much as possible See S-video Y’CbCr, YCbCr Y’CbCr is the color space defined by BT.601 and BT.709 Y’ is the luma component and the Cb and Cr components are color difference signals The technically correct notation is Y’Cb’Cr’ since all three components are derived from R’G’B’ Many people use the YcbCr notation rather than Y’CbCr or Y’Cb’Cr’ Y/C connection Popular two-signal interface format, where Y is a luminance component and C is a chrominance component at NTSC or PAL color subcarrier frequency Because the C signal is transmitted separately there are no cross-effects, so the decoded picture looks almost as good as the original The Y/C interface is used in DVD players, S-VHS and 8-mm VCRs, set-top boxes, televisions, plus related equipment Syn.: S-Video; Y/C interface Y/C connector A multipin input that helps to eliminate several types of video interference by processing the brightness (Y) and (C) portions of the signal separately Previously, the luminance and chrominance signals were mixed and had to be separated by the TV set By avoiding this intermediate step, the Y/C connector eliminates such interference problems as crosstalk Y/C connectors, usually installed on more recent TV monitor/receivers and other similar equipment, accept connections from DVD players, SuperVHS and Beta VCRs, set-top boxes, and some models of laserdisc players These inputs are sometimes known as S-video inputs or S-connectors YC-2 board Y (luminance) signal and C (chroma) signal record/playback circuits, Betamax VCR Y/C interface See Y/C connection Y/C separator A Y/C separator is what is used in a NTSC/PAL decoder to separate the luma and chroma This is the first thing that any video decoder must The composite video signal is fed to a Y/C separator so that the chroma can then be decoded further Y/C video See S-video yellow The color obtained by mixing equal intensities of green and red light yield strength Refers to the degree of force necessary to produce a 5% elongation in a videotape If a tape is stretched beyond this point, it may affect the overall quality so that the tape is unwatchable Y’IQ, YIQ The components of the NTSC system: luminance and chroma Also Y’IQ A color space optionally used in the NTSC video system The Y’ component is the black-and-white portion of the image The I and Q parts are the color difference compo- 317 Y matrix nents; these are effectively nothing more than color placed over the black and white, or luma, component Many people use the YIQ notation rather than Y’IQ or Y’I’Q’ The technically correct notation is Y’I’Q’ since all three components are derived from R’G’B’ Y matrix A circuit to construct luminance signal according to the equation Y = 0.299R’ + 0.587F’ + 0.114B’ (SDTV) or Y = 0.213R’ + 0.715G’ + 0.072B’ (HDTV) yoke Deflection yoke See also Flyback transformer Y’PbPr, YPbPr Y’PbPr is a scaled version of the YUV color space, with specific levels and timing signals, designed to interface equipment together Consumer video standards are defined by EIA-770; the professional video standards are defined by numerous SMPTE standards VBI data formats for EIA-770 are defined by EIA-805 Many people use the YPbPr notation rather than Y’PbPr or Y’Pb’Pr’ The technically correct notation is Y’Pb’Pr’ since all three components are derived from R’G’B’ Y signal Luminance signal Y’UV, YUV The components of the PAL system: lu- minance and chroma Also Y’UV The color space used by the NTSC and PAL video systems As with the Y’IQ color space, the Y’ is the luma component while the U and V are the color difference components Many people use the Y’UV notation when they actually mean Y’CbCr data Most use the YUV notation rather than Y’UV or Y’U’V’ The technically correct notation is Y’U’V’ since all three components are derived from R’G’B’ YUV9 Intel’s compressed YUV (actually YCbCr) format, providing a compression ratio of up to 3:1 The picture is divided into blocks, with each block comprising x pixels For each block, 16 values of Y, one value of U (Cb), and one value of V (Cr) are assigned The result is an average of nine bits per pixel YUV12 Intel’s notation for 4:2:0 YCbCr stored in memory in a planar format The picture is divided into blocks, with each block comprising x pixels For each block, four values of Y, one value of Cb, and one value of Cr are assigned The result is an average of 12 bits per pixel YUY2 Intel’s notation for 4:2:2 YCbCr format 318 Z zap The use of a remote-control device to change TV channels or turn off the sound during commercial messages; the use of a device to blip out commercials, as with a pause button in videotaping; also called zapping The A.C Nielsen company defines the term as the practice of eliminating commercials on a videocassette during playback, but most industry practitioners use zipping to describe that process zapping See Zap Z-axis modulation Intensity modulation Z.B An instruction to a camera operator to zoom back zelda A mannequin, generally just the head and shoulders, used to focus film or TV cameras zeroing Zeroing is what’s done to the bank of comparators in a CMOS flash A-to-D converter to keep them accurate Without zeroing, the comparators build up enough error so that the output of the flash ADC would no longer be correct To solve the problem, the comparators are “zeroed,” or the accumulated error removed Z demodulator Same as the X demodulator, except it is for the blue (B-Y) signal zebra tube A color display tube, so called from the vertical red, green and blue-emitting stripes that make up the phosphor screen, that closely resembles the apple tube It is one of the index types and, like the apple tube, makes use of index strips over the phosphors These index strips, instead of giving out secondary electrons, emit ultraviolet (UV) light that is amplified in a photomultiplier By ingenious circuitry, the need for a separate pilot electron beam is eliminated Zenith Spectrum-Compatible HDTV system Also SC-HDTV system, Spectrum-Compatible HDTV system A single-channel noncompatible simulcast HDTV system specifically designed to coexist with NTSC in the existing TV bands of terrestrial broadcasting Sharing of the existing TV bands requires the use of the so-called “Taboo” channels The camera of the SC-HDTV system progressively scans 787.5 lines, at 59.94 frames/s for a horizontal deflection frequency of 47.203 kHz, exactly three times the NTSC rate The R, G, B bandwidths extend over 37 The aspect ratio is 16:9 The number of active lines per frame is 720 and there are 1280 active pixels per line The video encoder applies adaptive + transform/sub-band coding Potentially, a full picture’s content is retained but in flat areas with little detail and little variation in the image, little information is transmitted This makes time available for the transmission of more information needed for areas of greater detail Adaptation and control information are transmitted separately during the vertical blank interval as part of the digital data signal zero frame dissolve A dissolve with a duration of zero frames, equivalent to a cut; a technique used to synchronize two source machines so that manual audio or video transitions can be made between them zero-subcarrier chromaticity The chromaticity that is intended to be displayed when the subcarrier amplitude is zero in a color TV system zip pan A rapid movement of the TV or film camera; also called blur, whip, or whiz See also Swish pan zipper On a TV or broadcast, an inconsequential, humorous, or even zany final item; also called kicker See Creepy-crawlies zipping TV-commercial avoidance during playback accomplished by fast-forwarding through taped commercials zonal mixing Keying mode when a key signal of the mixer (e.g., a diamond-shaped wipe pattern) comes from a source other than the video that will eventually fill the hole The key source, in this case, may be either internal or external Syn.: in-lay zone satellite See Satellite focus zoom To increase or reduce the size of a TV image, usually in a gradual way Zooming can be accomplished by means of electronics or optics See Digital zoom zoomed video port Used on laptops, the ZV Port is a point-to-point uni-directional bus between the PC Card host adapter and the graphics controller, enabling video data to be transferred real-time directly from the PC Card into the graphics frame buffer The PC Card host adapter has a special multimedia mode configuration If a non-ZV PC Card is plugged into the slot, the host adapter is not switched into the multimedia mode, and the PC Card behaves as expected Once a ZV card has been 319 zoom in plugged in and the host adapter has been switched to the multimedia mode, the pin assignments change zoom in Expansion of the picture details within the zoomed picture area Syn.: expand zoom lens Special lens that has a continuously variable focal length (and thus magnification) over a certain range without moving the camera Most video cameras come equipped with a standard 6:1 zoom lens (relationship of the longest focal length to its shortest) while some consumer models offer an 8x, 10x or even 12x variable power zoom lens The zoom may go from wide angle through normal viewing to close-up or vice versa This feature is usually adjusted by a zoom ring, a zoom ring lever or a power zoom that works electronically The focal lengths for video lenses are different from those used in still photography For example, a 12-75mm range in video would be equivalent to a 45-350mm lens on a 35mm camera zoom light An accessory normally used indoors with a video camera Some zoom lights can be connected to wall outlets while other models, if used in the field, can be plugged into the cigarette-lighter socket of an automobile zoom mode Mode of HDTV down-conversion in which the output picture is produced from part of an HDTV source picture with on-line control of its size and position Syn.: window mode [of HDTV down conversion] zoom out A zoom effect with objects being decreased in size Syn.: compression; reduction zoom ratio The telescoping range of a lens A mathematical expression of the two extremes of focal length available on a particular zoom lens The ratio depends on how close or large the subject appears in the finder compared to its original distance or size The typical zoom ratio is 6:1 although some cameras feature an 8:1 ratio Extender lenses are available; these extensions increase the zoom ratio For example, a particular extender lens may increase an 8:1 ratio to a 12:1 telephoto zoom zoom ring A control encircling the zoom lens Its backand-forth movement permits the mechanical adjustment of the focal length When the zoom ring is rotated, the focus is changed Other zoom controls are the zoom ring lever and the power zoom zoom ring lever A control on the zoom lens with an extended handle to help facilitate changing the focal length An intermediate control, it is easier to operate than the basic zoom ring, but not as sophisticated as the power zoom zoom To increase or reduce the size of a TV image, usually in a gradual way ZV port See Zoomed video port zweiton A technique of implementing stereo or dualmono audio for NTSC and PAL video One FM subcarrier transmits a L+R signal, and a second FM subcarrier transmits a R signal (for stereo) or a second L+R signal It is discussed in ITU-T BS.707, and is similar to the BTSC technique Z-wheel In the digital video effects sense, it describes a single coordinate control used for changing effects parameters in the Z-axis (perpendicular to the screen plane) Syn.: spinwheel Zworykin, Vladimir (1889–1982) Russian inventor of the iconoscope, a television transmitting tube, and the kinetoscope, a CRT that projects pictures it receives onto a screen 320 APPENDIX A ASSOCIATIONS Advanced Television Enhancement Forum (ATVEF) http://www.atvef.com/ Advanced Television Forum (ATVF) http://www.atvf.org/ Canadian Association of Broadcasters http://www.cab-acr.ca/ CEA Consumer Electronics Association (formerly CEMA) http://www.ce.org/ Digital Display Working Group http://www.ddwg.org/ Digital Television Group http://www.dtg.org.uk/ DTVIA Digital Television Industrial Alliance of China Enterprise Confederation http://www.dtvia.com/ DVB-MHP DVB-MHP (Multimedia Home Platform) http://www.mhp.org/ DVDA DVD Assocation http://www.dvda.org/ ETG Entertainment Technology Group http://www.etg.tv/ 321 ICDIA International CD-i Assocation http://www.icdia.org/ IEEE 1394 Trade Organization http://www.1394ta.org/ IMTC International Multimedia Telecommunications Consortium http://www.imtc.org/ Korea Multimedia Association http://www.multimedia.or.kr/ Linux4.tv http://www.linux4.tv/ LinuxTV.org http://www.linuxtv.org/ Media Communications Association http://www.mca-i.org/ MHP Forum Multimedia Home Platform Forum http://www.mhp-forum.de/ MIDI Manufacturers Association http://www.midi.org/ MPEG Industry Forum http://www.m4if.org/ Multimedia Benchmark Committee http://www.spec.org/gpc/ Multimedia CD Consortium Marantz Japan, Inc 35-1, 7-Chome, Sagamiono Sagamihara-shi, Kangawa Japan, 228 (81) 427-44-0431 FAX: (81) 427-48-1007 322 National Association of Broadcasters http://www.nab.org/ RTSP.org Real Time Streaming Protocol information and updates http://www.rtsp.org/ Satellite Broadcasting and Communications Association of America (SBCA) http://www.sbca.com/ 323 [This page left blank.] APPENDIX B STANDARDS ORGANIZATIONS AES Audio Engineering Society http://www.aes.org/ ATSC Advanced Television Systems Committee http://www.atsc.org/ DAVIC Digital Audio Visual Council http://www.davic.org/ DVB Digital Video Broadcast http://www.dvb.org/ DVD Forum http://www.dvdforum.org/ EBU European Broadcasting Union http://www.ebu.ch/ EIA Electronic Industries Association http://www.eia.org/ ETSI European Telecommunications Standards Institute http://www.etsi.org/ IEC International Electrotechnical Commission http://www.iec.ch/ IEEE Institute of Electrical and Electronics Engineers http://www.ieee.org/ 325 ISO International Organization for Standardization http://www.iso.ch/ ISMA Internet Streaming Media Alliance http://www.isma.tv/ ITU International Telecommunication Union http://www.itu.ch/ MPEG Moving Picture Experts Group http://mpeg.telecomitalialab.com/ OpenCable http://www.opencable.com/ SCTE Society of Cable Telecommunications Engineers http://www.scte.org/ SMPTE Society of Motion Picture and Television Engineers http://www.smpte.org/ TV Anytime http://www.tv-anytime.org/ TV Linux Alliance http://www.tvlinuxalliance.org/ VESA Video Electronics Standards Association http://www.vesa.org/ 326 ... weatherproof twist-lock coax connector standard on commercial video equipment and used on some brands of satellite receivers The most popular type of connector in professional TV and video BNR... (CD, phono, tape and line) and several video inputs (VCRs, DVD and cable/satellite set-top box) Some units permit two-way dubbing, includes S -video and component video terminals and offer memory... voice, video and data bandwidth efficiency In TV, the ratio of picture quality to RF bandwidth bandwidth, HDTV (color set and color-difference set) See SMPTE 240 standard bandwidth on demand Say you