M Terms

M/E: Mix/Effects or Mix Effects Amplifier. The portion (or "bank") of a video switcher where video signals are processed to select sources and create mixes, fades, wipes, keys, and other special effects.

MacBeth Chart: Color patch chart useful for colorimetry set-up.

Magneto-Optical Discs: An information storage medium that is magnetically recorded, and optically read. Two physical laws are exploited in this recorder, the Curie and Kerr effects. High power laser heat and the magnetic data combine to store the data on the disc (the Curie effect). The data is recovered by low power laser light passing through the magnetic field created by the data on the disc (the Kerr effect). The ability to tightly focus the laser greatly increases the data density over standard magnetic media. Magneto-Optical Disc drives can store up to 650 MB on a disc and have the capability of recording and erasing data for re-recording.

MAN: Metropolitan area network.

Mapping: 1.) Conversion of an audio signal from time to frequency domain by sub-band filtering and br by MDCT.

2.) The ability to take a two-dimensional graphics file of texture, wood grain, chrome, etc. and project it on an object, thus, wrapping the object with the chosen texture.

Master: The original videotape recording of a finished product.

Match Frame Edit: An edit where the video and audio do not change from where the previous edit ended. The match frame edit is primarily used to do A/B transitions such as dissolves and effects between two source decks.

Matrix Switcher: A video switching device which allows an operator to route any video signal to any source or monitor in the system.

Matrix Circuits: Any Circuit in which something new is developed from more basic elements. Within a camera, the matrix circuit creates the luminance Y signal and the two color difference signals R-Y and B-Y or I and Q signals. It creates these signals from the basic R,G, and B signals. Matrixing of the signal takes place prior to the encoding process.

Mavica: Magnetic video camera.

MBps: Megabytes per second: Million bytes per second or 8 million bits per second

Mbps: Megabits per second: Million bits per second.

MDCT: Modified Discrete Cosine Transform.

Mechanical Focus: The focusing of a camera lens or pick-up device by manual adjustment.

Media: Materials or technical means of communication using films, art, video, voice, music, computer programming, etc.

Media Integration: Apple's strategy for incorporating media such as sound and video into the Macintosh operating system so that motion video, voice, and music can be easily integrated into every application as graphics are today.

Megabyte (Mb): A unit of measurement equal to 1024 kilobytes (K) or 1,048,576 bytes. Data files: especially sound, graphics, and digital video files are measured in Mb.

MFJ: Modified Final Judgment: The federal court ruling that established the permitted lines of business and operational relationships between AT&T and the local Bell Operating Companies.

MFM: Multicarrier Frequency Modulation: FM radio and TV are examples of MFM

MHz: MegaHertz: Million Hertz. The bandwidth of the video signal is 4.2 MHz. A normal U.S. television transmission channel is 6 MHz.

Micons: Miniature Icons: Small graphic representations of media element types (Graphics, videotape, videodisc, Mac Sound, CD Sound, etc.)

Microprocessor: A central processing unit implemented on a chip.

Microwave:  1.) Electromagnetic waves with frequencies above one Gigaflertz. Used for line-of-sight, point-to-point or point-to-multipoint transmission of signals.

2.) Part of the electromagnetic spectrum, microwaves are high-frequency waves that exhibit highly directional characteristics. Microwave transmission of video signals is a common method of linking several sites in a CCTV system. Transmission by microwave requires modulating the video signal to a microwave carrier frequency, and demodulating the signal at the receiving end. Microwave transmission provides excellent picture resolution and can deliver signals in a line-of-sight over a radius of many miles.

MIDI: Acronym for Musical Instrument Digital Interface. MIDI is the communication standard for exchanging digital data between a musical instrument (e.g. a synthesizer or electric piano) and a MIDI equipped device.

Mil: One one-thousandth of an inch.

Mirror Mother Tape: In high-speed duplication Sprinter ¨ systems, a Mirror Mother machine makes a mirror image of the master tape. It is the mirror mother tape which is used on the Sprinter as a master for high-speed duplication.

Mixer: A device used to combine audio signals.

Mixing: Combining two or more audio or video sources.

MMDS: Multipoint Multichannel Distribution Systems: A video delivery system that uses microwave radio channels to broadcast signals over relatively small distances.

Modem: 1.) Modulator/demodulator: A device that uses frequency shift keying to modulate a low rate digital signal onto a carrier suitable for telephone line transmission. It can also receive low rate digital signals by demodulating the received carrier.

2.) A device used to accept digital signals and add them onto, or modulate them on, analog signals for transmission between sites. Modem is an abbreviation for MOdulator/DEModulator. A modem acts not only to convert digital signals to be transmitted in analog form, but likewise to demodulate the signals.

Modular vs. Built-in: Modular systems offer users the flexibility to relocate their equipment when facility plans change. Built-in systems offer greater ability to customize equipment to fit a unique application; for example, where more than two monitors are used or where very large monitors are required.

Modulation:  1.) The process by which some characteristic (i.e. amplitude, phase) of one RF wave is varied in accordance with another wave ( message signal).

2.) The process of adding information in the form of an analog signal to an existing signal carried by a transmission medium, i.e., a carrier. The added signal effectively "rides along" the transmission signal.

Motion Compensation: The use of motion vectors to improve the efficiency of the prediction of pel values. The prediction uses motion vectors to provide offsets into the past and/or future reference pictures containing previously decoded pel values that are used to form the prediction error signal.

Monitor: In video, a television without a tuner. A computer monitor usually accepts RGB rather than composite input. To watch or listen to, or the device through which monitoring takes place. In audio, the speakers used while recording tracks or mixing down.

Monochrome: Black and white.

Motion Estimation: The process of estimating motion vectors during the encoding process.

Motion Vector: A two-dimensional vector used for motion compensation that provides an offset from the coordinate position in the current picture to the coordinates in a reference picture.

Moving Coil Microphone: A low-impedance type of microphone that operates on electromagnetic principals.

MPEG: Motion Picture Experts Group.

1.) The standards committee made up of representatives from many manufacturers who are meeting to set standards for the compression of motion video images. Like JPEG, it is both a group and an algorithm.

2.) The ISOIIEC sanctioned group responsible for standardization of compression techniques for transmission and storage of moving images.

MPEG 1: Standard (1991) for compressing (in principal) progressive scanned images. Bit rate is 1.5 Mbps.

MPEG 2: Standard for compression of progressive scanned and interlaced video signals over a large range of compression rates with a range of bit rates from 1.5 to 100 Mbps.

MSO: Multiple System Operator of cable Systems in two or more places (i.e. TCI, Time Warner).

Multi-Cassette System: The primary hardware portion of a Library Management Systemª (LMS). It consists of a number of internal VTRs, an audio/video matrix switcher, cart controller, cassette storage console, VTR console, and elevator mechanism.

Multiscan¨ Monitor: A monitor capable of scanning at a range of frequencies, thus, allowing the use of various graphics adapters.

Multi-Track Recording: Recording technique where multiple tracks or channels of audio material are recorded separately and later mixed down to achieve optimum results for mono or stereo playback.

Multimedia: Usually refers to any presentation of information using more than one medium; for example, a presentation using text and video. More commonly refers to the integration of various media (especially videodisc, computer graphics, and text) through the use of a Personal Computer.

Multiplex: A method of transmission where more than one channel of information or video signal is transmitted over a single signal path. Demultiplexing separates each signal on receipt. Multiplexing would be used to provide transmission of several video sources over one carrier, thereby reducing total transmission costs. Fiber optics, coaxial cable, and microwave transmission schemes are all capable of multiplex transmission. TDM and FDM are examples of two methods of multiplexing.

Multipoint: A communication system which allows three or more sites to both transmit and receive signals. Using telephone conversations as an example, a typical individual-to-individual telephone call is referred to as a point-to-point call. A conference call is referred to as a multipoint call.

Multipoint Videoconference: A videoconference of three or more sites. A Multipoint Control Unit (MCU) can link up to eight or more remote sites into a single conference or manage as many as three simultaneous, independent conferences (segmenting). Multiple MCUs can be combined to increase the maximum number of sites in a single conference (cascading).

MUSE: Multiple sub-Nyquist encoding.

Musicam: MPEG 1/ MPEG 2 sanctioned audio encoding system.