Mobile Video: Glossary of mobile video terms
Active Matrix Display
Active Matrix also known as TFT (thin film transistor) Active Matrix offers better resolution than a conventional LCD monitor due to the faster refresh rate.
Aspect ratio
Is the ratio between the height and width of an image on a monitor. NTSC native aspect ratio is 4:3 or (1.33:1). When recorded, movies are made to fit a cinema widescreen, which is proportionally wider than a conventional TV. Generally cinema screens are at a ratio of 1.85:1 or 2.35:1 this number is usually referred to as 16:9 or letter box.
Letter box
Is a method of shrinking the video image so that the original aspect ratio is displayed on a 4:3 monitor. Letter box displays black bars at the top and bottom of the screen displaying the wide screen image as it was
Pan-and-scan
Is a method of displaying a widescreen movie on a normal 4:3 aspect ratio monitor. The outer portions of the movie a removed by the DVD player allowing a full screen video image.
Composite Video Output
A composite video signal is a signal that combines the color and black and white video information into a single cable. A “RCA” type cable is the most common type of composite video cable.<.p>
Digital Output
Digital outputs transmit a bitstream digital data. This data is used to carry a Dolby Digital or DTS audio program. A compatible decoder is needed to receive the signal. Digital outputs offer a broader frequency response, immunity to interference, and a single cable connection. Digital outputs come in two forms optical, and digital. For both a special cable is needed.
Diversity Antenna System
When a vehicle is moving, TV reception is difficult to get. TV tuners incorporating Diversity Antenna Systems monitor the antenna signal and select the antenna with the best reception. Diversity antennas require the installation of more than one antenna.
Dolby® Digital
Is a discrete, multichannel digital audio program. Dolby Digital is a 5.1-channel surround sound encoding method used to get a cinema like experience. A 5.1-channel system offers five discrete full-range channels, plus a subwoofer channel.
DVD players generally do not come with Dolby Digital Decoders. A sound processor and Dolby Digital encoded discs are needed to take advantage of Dolby Digital.
Dolby® ProLogic™
Dolby ProLogic is a matrix form of surround sound. Using an encoded 2 channel stereo audio program a decoder processes the information into three full range channels (left, center, right) and 1 limited range monaural channel (rear speakers). Dolby Pro logic provides a nice alternative to true discreet audio systems.
Digital Theater Systems (DTS®)
DTS is a multichannel audio format. DTS is a 5.1-channel format. The compression algorithm used in DTS compresses significantly less increasing the sound quality to a higher level than Dolby Digital. DTS to an astute listener sounds better. DTS soundtracks and titles are limited.
DVD Player
A DVD player plays DVD movies. Generally a DVD player can play CD’s. Certain DVD players come with MP3 decoders allowing the playback of an MP3 encoded CD. Specific units also come equipped with a TV tuner for of air TV reception.
LCD Monitor
A Liquid crystal Display is screen that converts a video signal into a picture. A monitor can be mounted in a seat back, floor console, or on the roof as a flip down.
S-video
S-Video unlike composite video carry the color information (chrominance) and the black and white information (luminance) on separate wires. An S-Video cable is a special four-pin connector, which gives improved color and reduces distortion.
Signal to Noise Ratio >
Is a measure of Signal to Noise in an audio or video program. In audio and video signal-to-noise is measured in decibels (dB). 6db is twice as loud as 3db. To put signal to noise ratio in a more understandable way, it is a way of measuring how clean a signal is. The higher signal to noise ratio the cleaner the signal, which makes for improved listening.
SRS®
Known as Sound Retrieval System is a device that processes a 2 channel stereo audio program and creates a matrix 360-degree type surround sound giving a cinema type experience.
TFT Screen
A type of LCD screen that uses thin film transistor (TFT) technology. Each pixel is controlled from 1 to 4 transistors, giving TFT screens the best resolution of all flat-panel displays.
TV Tuner
A TV tuner receives UHF and VHF television broadcasts (from channels 2 to 69), providing local programming for a mobile video system.
Video Cassette Player (VCP)
A video cassette player (VCP) is designed strictly for playback — it does not have the ability to record.