Make your own free website on Tripod.com

 

M...

MAC (A, B, C, D2)

Multiplexed analog component color video transmission system. Subtypes refer to the various methods used to transmit audio and data signals.

Macroblock

The four 8 by 8 blocks of luminance data and the two (for 4:2:0 chroma format), four (for 4:2:2 chroma format) or eight (for 4:4:4 chroma format) corresponding 8 by 8 blocks of chrominance data coming from a 16 by 16 section of the luminance component of the picture. Macroblock is sometimes used to refer to the pel data and sometimes to the coded representation of the pel values and other data elements defined in the macroblock header.

Margin

The amount of signal in dB by which the satellite system exceeds the minimum levels required for operation.

Master Antenna Television (MATV)

An antenna system that serves a concentration of television sets such as in apartment buildings, hotels or motels.

Mbps

Mega bits per seconds. Millions of bits per second.

MC - Management Component.

MCS - Message Control System.

Megahertz (MHz)

Refers to a frequency equal to one million Hertz, or cycles per second.

Microwave

Line-of sight, point-to-point transmission of signals at high frequency. Many CATV systems receive some television signals from a distant antenna location with the antenna and the system connected by microwave relay. Microwaves are also used for data, voice, and indeed all types of information transmission. The growth of fiber optic networks have tended to curtail the growth and use of  terrestrial microwave relays.

Microwave Interference

Interference which occurs when an earth station aimed at a distant satellite picks up a second, often stronger signal, from a local telephone terrestrial microwave relay transmitter. Microwave interference can also be produced by nearby radar transmitters as well as the sun itself. Relocating the antenna by only several feet will often completely eliminate the microwave interference.

Modulation

The process of manipulating the frequency or amplitude of a carrier in relation to an incoming video, voice or data signal.

Modulator

A device which modulates a carrier. Modulators are found as components in broadcasting transmitters and in satellite transponders. Modulators are also used by CATV companies to place a baseband video television signal onto a desired VHF or UHF channel. Home video tape recorders also have built-in modulators which enable the recorded video information to be played back using a television receiver tuned to VHF channel 3 or 4.

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.

Motion Estimation

The process of estimating motion vectors during the encoder 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.

MPEG - Motion Picture Experts Group

A proposed International Standards organization (ISO) standard for digital video and audio compression for moving images.

MPEG-1

1/4 broadcast quality which translates to 352 x 240 pixels. Typically compressed at 1.5 Mbs.

MPEG-2

Similar to MPEG-1, but includes extensions to cover a wider range of applications. MPEG-2 translates to 704 x 480 pixels at 30 frames per second in North America and 704 x 576 fps at 25 fps in Europe. Typically compressed at higher than 5 Mbs. The primary application targeted during the MPEG-2 definition process was the all-digital transmission of broadcast TV quality video.

MPS - Master Program Scheduler

Multiplex

The output signal from an encoder that is divided into two phases. One half is called the I multiplex, and the other is called the Q multiplex. UCS channels 0 through 4 are transmitted in the I multiplex and channels 5 through 9 are transmitted in the Q multiplex. Each multiplex contains control channel messages (messages addressed to the decoders originating from the encoder and the UCS), as well as video, audio, and data information.

Multicast

A special form of broadcast where copies of the packet are delivered to only a subset of all possible destinations.

Multiplexing

A means of transmitting two or more signals over a single wire or carrier wave.

 

Please choose another letter or use the back button.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
BACK