DVD Glossary Part 3 (E

edge enhancement - When films are transferred to video in preparation for DVD encoding, they are commonly run through digital processes that attempt to clean up the picture. These processes include noise reduction (DVNR) and image enhancement. Enhancement increases contrast (similar to the effect of the "sharpen" or "unsharp mask" filters in PhotoShop), but can tend to overdo areas of transition between light and dark or different colors, causing a "chiseled" look or a ringing effect like the haloes you see around streetlights when driving in the rain. Video noise reduction is a good thing, when done well, since it can remove scratches, spots, and other defects from the original film. Enhancement, which is rarely done well, is a bad thing. The video may look sharper and clearer to the casual observer, but fine tonal details of the original picture are altered and lost.

EDS - Enhanced data services. Additional information in NTSC line such as a time signal.

EDTV - Enhanced-definition television. A system which uses existing transmission equipment to send an enhanced signal which looks the same on existing receivers but carries additional information to improve the picture quality on new enhanced receivers. PALPlus is an example of EDTV. (Contrast with HDTV and IDTV.)

EFM - Eight-to-fourteen modulation. A modulation method used by CD, where eight data bits are represented by 14 channel bits. The 8/16 modulation used by DVD is sometimes called EFM plus.

EIA - Electronics Industry Association. (See Appendix C.)

E-IDE - Enhanced Integrated Drive Electronics. Extensions to the IDE standard providing faster data transfer and allowing access to larger drives, including CD-ROM and tape drives, using ATAPI. E-IDE was adopted as a standard by ANSI in 1994. ANSI calls it Advanced Technology Attachment-2 (ATA-2) or Fast ATA.

elementary stream - A general term for a coded bitstream such as audio or video. Elementary streams are made up of packs of packets.

emulate - To test the function of a DVD disc on a computer after formatting a complete disc image.

encode - To transform data for storage or transmission, usually in such a way that redundancies are eliminated or complexity is reduced. Most compression is based on one or more encoding methods. Data such as audio or video is encoded for efficient storage or transmission and is decoded for access or display.

encoder - 1) A circuit or program that encodes (and thereby compresses) audio or video; 2) a circuit that converts component digital video to composite analog video. DVD players include TV encoders to generate standard television signals from decoded video and audio; 3) a circuit that converts multichannel audio to two-channel matrixed audio.

Enhanced CD - A general term for various techniques that add computer software to a music CD, producing a disc which can be played in a music player or read by a computer. Also called CD Extra, CD Plus, hybrid CD, interactive music CD, mixed-mode CD, pre-gap CD, or track-zero CD.

entropy coding - Variable-length, lossless coding of a digital signal to reduce redundancy. MPEG-2, DTS and Dolby Digital apply entropy coding after the quantization step. MLP also uses entropy coding.

EQ - Equalization of audio.

error-correction code - Additional information added to data to allow errors to be detected and possibly corrected. See Chapter 3.

ETSI - European Telecommunications Standards Institute. (See Appendix C.)

father - The metal master disc formed by electroplating the glass master. The father disc is used to make mother discs, from which multiple stampers (sons) can be made.

field - A set of alternating scan lines in an interlaced video picture. A frame is made of a top (odd) field and a bottom (even) field.

file system - A defined way of storing files, directories, and information about them on a data storage device.

file - A collection of data stored on a disc, usually in groups of sectors.

filter - (verb) To reduce the amount of information in a signal. (noun) A circuit or process that reduces the amount of information in a signal. Analog filtering usually removes certain frequencies. Digital filtering (when not emulating analog filtering) usually averages together multiple adjacent pixels, lines, or frames to create a single new pixel, line, or frame. This generally causes a loss of detail, especially with complex images or rapid motion. See letterbox filter. Compare to interpolate.

FireWire - A standard for transmission of digital data between external peripherals, including consumer audio and video devices. The official name is IEEE 1394, based on the original FireWire design by Apple Computer.

fixed rate - Information flow at a constant volume over time. See CBR.

forced display - A feature of DVD-Video allowing subpictures to be displayed even if the player’s subpicture display mode is turned off. Designed for showing subtitles in a scene where the language is different from the native language of the film.

formatting - 1) Creating a disc image. 2) Preparing storage media for recording.

fps - Frames per second. A measure of the rate at which pictures are shown for a motion video image. In NTSC and PAL video, each frame is made up of two interlaced fields.

fragile watermark - A watermark designed to be destroyed by any form of copying or encoding other than a bit-for-bit digital copy. Absence of the watermark indicates that a copy has been made.

frame doubler - A video processor that increases the frame rate (display rate) in order to create a smoother-looking video display. Compare to line doubler.

frame rate - The frequency of discrete images. Usually measured in frames per second (fps). Film has a rate of 24 frames per second, but usually must be adjusted to match the display rate of a video system.

frame - The piece of a video signal containing the spatial detail of one complete image; the entire set of scan lines. In an interlaced system, a frame contains two fields.

frequency - The number of repetitions of a phenomenon in a given amount of time. The number of complete cycles of a periodic process occurring per unit time.

G byte - One billion (10⁹) bytes. Not to be confused with gigabyte (2³⁰ bytes).

G - Giga. An SI prefix for denominations of 1 billion (10⁹).

Galaxy Group - The group of companies proposing the Galaxy watermarking format. (IBM/NEC, Hitachi/Pioneer/Sony.)

GB - Gigabyte.

Gbps - Gigabits/second. Billions (10⁹) of bits per second.

gigabyte - 1,073,741,824 (2³⁰) bytes. See the end of Chapter 1 (p. 12) for more information.

GOP - Group of pictures. In MPEG video, one or more I pictures followed by P and B pictures. A GOP is the atomic unit of MPEG video access. GOPs are limited in DVD-Video to 18 frames for 525/60 and 15 frames for 625/50.

gray market - Dealers and distributors who sell equipment without proper authorization from the manufacturer.

Green Book - The document developed in 1987 by Philips and Sony as an extension to CD-ROM XA for the CD-i system.

H/DTV - High-definition/digital television. A combination of acronyms that refers to both HDTV and DTV systems.

Half D1 - MPEG-2 picture resolution of 352 x 480 (NTSC) or 352 x 576 (PAL/SECAM). See HHR.

HAVi - A consumer electronics industry standard for interoperability between digital audio and video devices connected via a network in the consumer’s home.

HDCD - High-definition Compatible Digital. A proprietary method of enhancing audio on CDs.

HDTV - High-definition television. A video format with a resolution approximately twice that of conventional television in both the horizontal and vertical dimensions, and a picture aspect ratio of 16:9. Used loosely to refer to the U.S. DTV System. Contrast with EDTV and IDTV.

Hertz - See Hz.

hexadecimal - Representation of numbers using base 16.

HFS - Hierarchical file system. A file system used by Apple Computer’s Mac OS operating system.

HHR - Horizontal Half Resolution. MPEG-2 picture resolution of 352 x 480 (NTSC) or 352 x 576 (PAL/SECAM). Supported by the DVD-Video specification. Encoding video at HHR greatly reduces the bandwidth with a minor reduction in picture quality. Also called Half D1.

High Sierra - The original file system standard developed for CD-ROM, later modified and adopted as ISO 9660.

horizontal resolution - See lines of horizontal resolution.

HQ-VCD - High-quality Video Compact Disc. Developed by the Video CD Consortium (Philips, Sony, Matsushita and JVC) as a successor to VCD. Evolved into SVCD.

HRRA - Home Recording Rights Association.

HSF - See High Sierra.

HTML - Hypertext markup language. A tagging specification, based on SGML (standard generalized markup language), for formatting text to be transmitted over the Internet and displayed by client software.

hue - The color of light or of a pixel. The property of color determined by the dominant wavelength of light.

Huffman coding - A lossless compression technique of assigning variable-length codes to a known set of values. Values occurring most frequently are assigned the shortest codes. MPEG uses a variation of Huffman coding with fixed code tables, often called variable-length coding (VLC).

Hz - Hertz. A unit of frequency measurement. The number of cycles (repetitions) per second.