Digital Media Glossary



ACM: Standing for Association for Computing Machinery - A large and longstanding professional organization dedicated to most of the important issues related to computers.

ADSL: Standing for Asymmetric Digital Subscriber Loop. ADSL is a technology that enables digital material to be sent down existing copper telephone lines.

API: Standing for Application Program Interface - An interface, used by application programmers, to gain access to an operating system, a device, another program, or a network. It typically consists of a collection of procedure calls with parameters.

Artifacts Refers to "undesirable" side effects of digitization and/or compression. Typical artifacts from compression include a "blockiness" in elements of the video.

ASDL:Standing for Asymmetric Digital Subscriber Loop. ASDL is a technology that enables digital material to be sent down existing copper telephone lines.

ATM:Standing for Asynchronous Transfer Mode. ATM is a high speed switching technology that facilitates the transfer of large volumes of audio-visual data involved in, say, high definition television (HDTV) or digital video.

ATV: Standing for Advanced Television. ATV is a term used to generally describe all types of television distribution technologies that deliver higher quality audio and video than the current NTSC standard.

ATWG: Standing for Architecture Technical Working Group - The primary technical working group of the IMA Compatibility Project.

Authoring : Refers to a process implemented by a "developer" whereby a multimedia application is "programmed" into a series of icons, menus, hypermedia, etc.

BRI: Standing for Basic Rate Interface. BRI is the smallest and simplest type of ISDN line available; also called 2B&D

Bandwidth: The volume of information, measured in hertz or bits, that a modem or communications device can transmit in a specified period of time.

Broad band: Any transmission system that can deliver more voice, video and data than a standard voice-grade telephone line in terms of capacity

Cable: Cable is generally used to describe the services that are transmitted over wires rather than over the airways.

Cableco: Abbreviated form of cable company

CATV: Standing for Co-Axial Television. So called because the wire used is a copper-based co-axial cable... Also referred to as Cable TV

Cable Act of 1994: The Cable "Punishment" Act in which Cable Operators were forced to reduce their costs to subscribers and simplify their packaging of services.

Cable Labs: Develops technology and standards for the Cable TV industry. It is funded by major Cable operators.

Cable Modem: A device that enables a user to connect their computer to existing Cable TV networks at Ethernet speeds and access Internet and/or On-line services. This can be much faster than a telephone modem, even operating at 14.4Kbs or 28.8Kbs.

Channel capacity: The number of channels that can be carried on a given system

CD: Standing for Compact Disk A "compact disk" that plays music when placed in a CD player. The audio is actually in digital format and sampled at 44.1KhzThis disk looks and feels the same as a CD-ROM, but a CD has only music whereas a CD-ROM has anything a computer can read plus audio and video.

CD-I: Standing for Com Disc Interactive, CD-i It is the interactive multimedia platform developed by Philips.

CDMA: Standing for Code Division Multiple Access - A method of concurrent transmission whereby packets of data are "coded" to differentiate them from other packets. This is the latest technology and relates to TDMA, an older technique, still widely in use, but not as fast.

CD-ROMs : Standing for Compact Disk Read-Only-Memory - A compact 5-1/4 inch optical disk, typically used to store text, images, audio, video, and programs which can run on suitably equipped computers. CD-ROM drives come in single, double, and quad speeds (150KBs, 300KBs, and 600KBs,

CDROM-XA: The prevalent standard for pressing CD-ROM disks which includes the interleaving of digital audio and digital video for playback on computers.

CISC: Standing for Complex Instruction Set Computer - This type of computer architecture has long/complex instructions which are general purpose and powerful, but considered to be slower than RISC computers (see elsewhere). The Intel x86 chips are CISC technology.

Codec: Refers to a "device" that Encodes/Decodes

Compression: The art/science of reducing the number of bits required to store and/or transmit digital media. Predominant schemes include MPEG 1, MPEG 2, motion JPEG. MPEG performs intra-frame compression as well as inter-frame (or differences from frame-to-frame) compression. JPEG, which is predominantly a still-image compression scheme, performs only intra-frame compression.

Content Packager: A company, organization, or person that "packages" a collection of applications together into a service. A content packager typically does not own the content.

Content Provider: A company, organization, or person that has/owns content and provides it to users, typically packaged in an application or service.

Convergence: The term used to describe both the coming together of computing, telecommunications and TV technologies and the formation of alliances between technological companies

Couch Potato: The person who sits on their couch and watches the TV passively for hours. These people are keeping Interactive TV providers awake 24 hours a day worrying.

Data stream protocol: The platform media independent part of a data stream that facilitates the time critical delivery and sychronization of time-based media.

DAVIC: Standing for Digital Audio Visual Council - Digital Audio Visual Council. International group of approximately 250 companies developing an "End-to-End" standard for Interactive Digital Media including interfaces and requirements for applications, systems, servers, set top units, and networks. This group is a spinoff from the MPEG committee.

DAVID: Standing for Direct Broadcast Services it is through this technology, satellites are able to beam digital television signals that have CD-quality sound and laserdisc quality images directly to the home.

DBS: Standing for Direct Broadcast Services it is through this technology, satellites are able to beam digital television signals that have CD-quality sound and laserdisc quality images directly to the home.

Delayed Broadcast: A proposed video service whereby a program is viewed at a later time by the viewer in addition to its "live" slot or "primetime" slot.

Digital: In contrast to the analog process, the encoding of electronic information in the form of discrete "on" or "off" pulses. Digital signals use binary codes (0s and 1s) to represent the original signal

Digital Editing: Refers to the editing of audio, images, video, text, etc. on PCs, Macintoshes, or workstations. In digital editing systems, the media are edited in their digital formats (as opposed to analog). Some editing products provide for "offline" editing, in which the final pass is done back in the analog domain via EDLs (Edit Decision Lists). Others provide "online" editing in which the final edited sequence is itself in digital format.

Digital Media: Refers to video and audio after having been digitized into 1s and 0s.

Digital Set Top: Refers to the new generation of television set top units that accept digital video as well as analog (traditional) video. Some digital set top units enable interactivity and therefore support shopping, banking, games, etc.Also referred generically as Set Top Unit (STU)

Digitization: The art/science of converting analog video, images, or audio into digital format (i.e., 1s and 0s)

Distance Learning: A new form of learning whereby a student can learn from anybody or any source from anywhere via their computer or television. This is being enabled technologically by things such as Internet, multimedia, etc., and has great promise as it is a student "pull" model as opposed to a teacher "push". It also enables learning by doing and discovering, as well as learning when/where you want.

DSMCC: Standing for Digital Store Management Command & Control - Part 6 of the MPEG 2 specification which specifies a control protocol for MPEG 2. DSMCC is not a standard as of this definition.

DSP: Standing for Digital Signal Processor - A specialized chip and/or system that is dedicated to processing real-time signals. Typically used for modems, audio, imaging, and video applications.

DVD: Standing for Digital Video Disk - A new standard for supplying video on CD-ROMs utilizing MPEG 2

EIA: Standing for Engineering Interface Association - An standards setting "engineering" body.

Encryption: The art/science of "encoding" data so that it cannot be interpreted by anybody or any machine that does not have the "code". Cable TV calls this process "scrambling" in a traditional cable TV system.

Ethernet: The prevalent network topology for LANs. Ethernet is a 10Mbs network.

FCC: Standing for Federal Communications Commission - Chief "communications" regulatory agency of the US Government.

Fiber Optics: Optical fiber. A flexible, hairlike, glass or plastic conduit for light waves. The light waves can be modulated by a television signal and sent great distances without experiencing many of the disadvantages of other point-to-point links

Forelash: Similar to "backlash" except that it involves negative feedback on something that doesn't even exist yet, such as forelash to Interactive TV.

FTTC: Standing for Fiber to the Curb

FTTH: Standing for Fiber to the Home

FTTO: Standing for Fiber to the Office

HDTV: Standing for High Definition Television, HDTV is a broadcast standard that produces images at least twice as sharp as the current NTSC and PAL/SECAM standards. There is no world-wide standard, although a leading contender is the NHK/Sony Hi-Vision system

HFC: Standing for Hybrid Fiber Coax - Refers to a broadband network (usually Cable TV or Interactive TV) that utilizes Fiber from a centralized location(often referred to as a "head-end") to an optical node (typically serving a neighborhood) from which coax cable runs to the home.

Home Shopping: In Interactive TV, you will be able to browse products, stores, prices, etc. at your convenience and even order the product(s) without your hand ever leaving the remote control or your derriere leaving the couch. They'll even be delivered to you house.

Hypermedia: A term referring to the ability to associate an object (such as a word, picture, icon, graphic, audio, or video) with another object. These objectsmay be physically on different computers and/or different countries, all ofwhich are transparent to theuser. A user can traverse over the hypermedia link by "clicking"on theobject. It's cool and also the prime enabler of the World Wide Web on Internet.

IDE: Standing for Internal Device Equipment - Typically refers to a type of disk controller. Most internal floppy drives and many internal hard drives are IDE

IDL: Standing for Interface Definition Language - A meta-language for describing computer and network-based algorithms and/or protocols. It is implementation independent.

IEEE: Standing for Institute of Electrical and Electronics Engineering - Develops electrical standards and also local area network and some cable network standards

IHU: Standing for In-Home Unite it is a microprocessor-based device connected to the television that has memory to store interactive applications and other information.

IHV: Standing for Independent Hardware Vendor - A vendor of hardware independent from the manufacture of the hardware in which the hardware runs.

IMF: Standing for Interactive Media Forum - Interactive Media Forum. The primary meeting body of the IMA for addressing business and technology issues surrounding multimedia.

Indeo: Intel's version of digital video system. Can be played on PCs without additional hardware.

Information Superhighway: Refers to the concept of a high bandwidth network that links everyone with everyone and can transport all media types. The Information Superhighway links the concepts of on-line services, Internet, and Interactive TV together.

Interactive Advertising: A new form of advertising in which the user actually selects an Ad and interacts with it, rather than it being forced upon the viewer.

Interactivity: Refers to computer programs, online services, and "Interactive TV" whereby the user can make inputs which direct subsequent delivery of services. Channel surfing is a crude form of interactivity. Internet and Online Services provide simple forms of interactivity, i.e., point-and-click.

Internet: Originally a network funded by the US Defense Department (DARPA) to provide a network of interconnected computers with multiple paths to each so that if any single computer or network link was destroyed in a war, information could still be transmitted and received by alternative computers and network paths.Today Internet has become the Global Information Super Highway connecting almost every country in the world together. Anybody with a computer, a modem, and some money can connect. Most Online Services are also providing Internet connectivity in order to survive.Internet is not a broadband network. It is a network of networks operating wide area computer networks topologies.

Interoperability: The ability to seamlessly mix and match pieces of gear from different manufacturers.

IPR: Standing for Intellectual Property Rights - The protection of content and ownership, primarily in the area of digital media.

ISA: Standing for Industry Standard Architecture - A de facto standard I/O channel, generally for IBM PC compatible computers.

ISDN: Standing for Integrated Services Digital Network - A scheme for sending digitized voice and data over existing phone lines

ISO: Standing for International Standards Organization

Isochronous: A constant-rate of transmission. This is needed for video and audio streams. Networks typically allocate, or reserve, bandwidth for Isochronous services.

ISV: Standing for Independent Software Vendor - An organization that develops software which is independent of any hardware product or platform vendor.

JPEG: Standing for Joint Photography Experts Group - A still image compression standard developed by ISO.

Kilo: One thousand.

Kbps: Standing for Kilo bits per second - Thousands of bits per second. Hence 14.4Kbps means 14,400 bits per second.

Khz: Standing for Kilohertz - Kilo means thousand and "hertz" means cycles so 1 Khz means 1 thousand cycles per second.

Level 1 Gateway: Also referred to as Video Dialtone. A Level 1 Gateway enables multiple Video Service Providers to connect over a broadband network to a user or subscriber. It enables the user to select the Video Service Provider of their choice, which may not be the "owner" of the fiber or wires that deliver the service.

LAN: Standing for Local Area Network - A scheme allowing computers to communicate with each other over short distances. Typical LANs are Ethernet and Token Ring.

MMDS: Standing for Multichannel Multipoint Distribution. Microwave transmissions are received by rooftop antennas; technology is limited to line-of-sight transmission

Mbps: Standing for Mega bits per second - Millions of bits per second

Mega: One million. Mhz: Standing for Megahertz - Mega means million and "hertz" means cycles so 1 Mhz means 1 million cycles per second.

MIDI: Standing for Musical Instrument Digital Interface - Interface used to connect musical instruments to computers.

MIME: Standing for Multipurpose Internet Mail Extensions

MMDS: Standing for Multichannel Multipoint Distribution. Microwave transmissions are received by rooftop antennas; technology is limited to line-of-sight transmission

Modem: Refers to a device that modulates/demodulates. A modem is typically used to connect a computer to a telephone line.

MPEG 1: Motion Picture Experts Group; a group within ISO. Compressed digital video/audio stream. MPEG 1 is 1/4 broadcast quality which translates to 352x240 pixels. Currently an ISO standard. Typically compressed at 1.5Mbs. Pronounced "m-peg".

MPEG 2: Standing for Motion Picture Experts Group, MPEG is the consortium of hardware, software and publishing interests dedicated to developing international standards for the compression of moving video images in digital systems. MPEG 1 is designed for use in CD-ROM drives, whereas MPEG 2 addresses broadcasting and videoconferencing

MSO: Standing for Multiple System Operator. A MSO is a compnay that owns more than one cable television system

Multimedia: A technology that takes 3 trips to the car and 4 phone calls to the manufacturer or store to install. Historically referred to as "rocket science". Also a $0 million dollar business quickly growing to a $0 billion dollar business.

NAB: Standing for National Association of Broadcasters - An association which helps you take advantage of current and future multimedia technologies and applications.

NDL: Standing for National Demonstration Laboratory

NIST: Standing for National Institute for Standards & Technology - US-based standards organization. Pronounced "nist"

NSP: Standing for Network Service Provider - Refers to the owner of the network. The service provider may be a different organization In telephony, when you place a long distance call, you utilize two network providers (your local phone company and your long distance phone company).In Cable TV, the cable operator provides both the network and the television service.Online Services don't typically own the network, but utilize a network provider to deliver their service.

NTSC: Standing for National Television Standards Committee. NTSC is the broadcasting standard used in the US, Canada, Mexico and in some Latin American and Asian Countries

NVOD: Standing for Near Video on Demand. NVOD is the system of scheduling multiple movies, with closely staggered starting times, to approximate true video on demand without the cost or complexity of new technology

OC x: Standing for Optical Carrier - Optical Carrier at a multiple of 51Mbs. Hence an OC 12 connection is 12 * 51Mbs or approximately 612Mbs.

OMF & MFI: Standing for Open Media Framework & Open Media Framework Interchange - Defacto standard put forth by Avid Technologies for specifying multimedia data and control in an open manner for digital editing and playback.

OMG: Standing for Object Management Group - An organization that has developed standards and products associated with Object Management in a distributed networked environment. OMG is best known for its CORBA work (The Object Request Broker).

PAL: Standing for Phased Alternate Line. PAL is the broadcasting standard used primarily in Europe and Austrailia, as well as some Latin American and Asian countries

Parallel: Typically refers to a "port" on a computer used to send several bits in parallel (usually 8-bits). Many printers connect to a parallel port.

PIC: Standing for Picture Image Compression, PIC is a compression standard for still mages and one of three compression levels. The other two being RTV and PLV .

Pinking: A process, developed by Phillips for blending elementary audio and video into a combined stream which can be stored and played on CD-I players.

Point-to-Multipoint: A single source of information/service deliver to many. Typically involved in broadcast television.

PLV:Standing for Production Level Video Compression, PLV is the highest level of compression that currently can create VCR quality images. It is one of the three standards, the other two being RTV and PIC

PLV: Standing for Production Level Video Compression, PLV is the highest level of compression that currently can create VCR quality images. It is one of the three standards, the other two being RTV and PIC

POTS: Standing for Plain Old Telephone System is the twisted copper wire, presently in place, that most telecommunications are replacing

QOS: Standing for Quality of Service - A methodology for delivering similar "content" at different "levels" of quality and/or service. This is determined by both the content provider and user. Pronounced 'q-o-s'

Quicktime: Apple Computer's version of digital video system.

RBOC:Standing for Regional Bell Operating Companies

RISC: Standing for Reduced Instruction Set Computer - A type of computer architecture which has a small, or reduced, set of instructions that execute very quickly.

RBOC: Standing for Regional Bell Operating Companies

ROM: Standing for Read Only Memory, ROM is a read only memory that can be read but not written to. Unsurprisingly, programmable ROMıs and Erasable ROMs can be programmed and reprogrammed respectively.

RTV: Standing for Real Time Video Compression, RTV is a compression level that handles video images. It is one of three. The other two being PIC and PLV

Teleco: Abbreviated form of telecommunications company

SCSI: Standing for Small Computer System Interconnect - SCSI refers to a type of controller system that enables users to connect devices to their computer. It is an alternative to IDE for disk controllers. SCSI is both a connection and bus. SCSI enables the user to connect up to 7 devices, in a daisy chain, to one SCSI port.

SMATV: Standing for Satellitie Master Antenna Television. SMATV is an established technology used in densely populated areas where a master satellite dish recives a signal for multiple customers, who are connected to the dish by conventional wiring.

SMDS: Standing for Switched Multi-megabit Data Services - A "fast-packet" service that sets up high-speed connections between sites.

SMPTE: Standing for Society of Motion Picture Television Engineers - Is an international technical society devoted to advancing the theory and application of film, television, video, computer imaging, telecommunications, and the related arts and sciences.

SONET: Standing for Synchronous Optical Network. SONET is a standard for extremely high speed transmission technology

STU & STB: Standing for Set Top Unit & Set Top Box - Typically refers to the device that sits on top of the TV for current Cable TV reception. Also refers to digital set top units which accept digital media and sometimes support interactivity.

TDMA: Standing for Time Division Multiple Access - A method of sharing a transmission medium by dividing the time into "slots" and allocating those slots to users on a network.

Teleco: Abbreviated form of telecommunications company

Telecommunications Act: Current bills in US Congress to eliminate measures such as RBOCs from entering long distance service, video services, and manufacturing of equipment.

TIA: Standing for Telecommunications Industry Association -Develops and sets telecom network and equipment standards.

Touchscreen: A device/technology that enables a user to touch a computer monitor to make a selection. Typically used in a kiosk.

VASP: Standing for Value Added Service Provider - Refers to the company, organization or person that provides digital media services.

VDT: Standing for Video Dial Tone. VDT is a general term encompassing the wiring and equipping of a specific location to recieve video programming on a selective basis

VEIL: Standing for Video Encoded Invisible Light the VEIL technology allows digital information to be encoded directly into the picture portion of a video signal for delivery to an interactive receiver in the home without the need for additional bandwidth to deliver data. The VEIL technology embeds information by changing the luminance of alternating lines of resolution in the picture fields that comprise a video signal, the net result of which is an electronically detectable data signal. VEIL is imperceptible, does not interfere with existing broadcast or cable television systems, and is compatible with existing television sets.

VASP:Standing for Video Encoding and Transport System, this component encodes the interactive information onto the actual video signal transmitted to the television.

Video Server: Refers to a specialized server that delivers constant-rate "streams" of digital video and/or audio. Used extensively for VOD

VOD: Standing for Video on Demand. VOD is the ability for a system user to select from a list of available movies, select one, and begin to view it immediately, at any time.

X.25: The premier packet service, often used in large "value-added networks" to move text information from terminals to large computer systems.