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

A

AAC

(Advanced Audio Coding), was popularized by Apple through its iPod and iTunes Music Store. AAC is promoted as the successor to MP3 with improved performance for audio coding at medium to high bit rates. The Codec quality is again excellent however playback is unfortunately mostly limited to Apple hardware.

AGC

Automatic Gain Control adjusts the signal to ensure a consistent amplitude regardless of input level fluctuations.

analogue

Any measure which varies continuously without distinct steps (compared to digital which is '0' or '1'). For an video signal, this refers to the continuous variation in current or voltage.

archive

A collection of files gathered and often compressed for storage or backup purposes.

aspect ratio

Describes the horizontal to vertical ratio of dimensions on a display.  For example traditional TVs are 4:3 aspect ratio.

AVI

(Audio Video Interleave), Microsoft's Video standard for Windows based computers.

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B

bandwidth

The amount of data that can be processed by a device. For example the amount of data sent through a network interface card (NIC) in a fixed amount of time. Bandwidth is measured in Kilobits or Megabits per second (Kbps or Mbps).

bit rate

The bit rate defines how much musical (or video) information is captured and stored for every second of media. Bit Rates are quoted in kilobits per second. Simply put, the higher the bitrates, the closer the encoding is to the original source.

blooming

The video equivalent of audio distortion. Most apparent on very bright subjects or high exposure.

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C

cache (memory)

A high speed storage device. For example Level 1 cache within a microprocessor core which allows for rapid manipulation of the data within the processor itself without having to request the data from 'slow' main memory.

capture

To record a still or moving image on storage media, for example tape or flash memory. Also to transfer data from one format to another by using a PC and dedicated hardware for the purpose.  For example a Video capture card can capture analogue video and convert it to Digital format.

clipping

Audible distortion as a result of flattening off the tops of an audio signal (from too loud an input or insufficient amplification to reproduce the true input signal).

CCD

(Charge Coupled Device) used in video and digital cameras to convert the image into electrical signals.

codec

A technology that compresses and decompresses data. A codec can be used to compress files for transport over a network, the Internet, or to decrease size for storage. The codec then expands files to their original size so that they can be played or viewed on a computer. Stands for compressor/decompressor.

compression

The process or result of converting data to a storage format that requires less space than the original data. Strictly speaking FLAC is a Compression (lossless) only format, whereas MP3 is an encoded (lossy) format.

convert

To change media or file from one format to another.

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D

database

An electronic filing system where a computer stores and can quickly access the data.

decode

To read (or view) a specific file format and translate it into another format.

digital

A measurable quantity represented by a numerical code of 1's & 0's. For audio it is the conversion of an analogue waveform to a digital number representing the instantaneous amplitude for each sample taken.

DIGITAL8

The next generation format after video8 & Hi8 introduced by SONY. Equipment used the same tape format to record Digitally and yet was backwards compatible with its analogue predecessors.

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E

encode

To write (or save) a specific file format often converted from a different format. Music encoding is the process of selectively compressing the original file using one of the many codecs available e.g. MP3.

encryption

A method of converting data into a secure format. You need a password or key to read an encrypted file.

EQ / Equalization

To increase or decrease certain portions of the audio spectrum to enhance the listeners pleasure or to compensate for deficiencies in the original.

export

To move data from one application to another. The data is placed into a generic format or one that the other application understands. Music files can be exported from a PC to a portable player and the Media player software may recode the files on-the-fly to conserve storage space on the portable.

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F

file format

A standard for encoding information in a file. Each type of file has a different file format that specifies how the information is organized and is generally specific to a particular application.

filter

A tool that can used to reduce an undesirable sound effect in an audio track. For example to filter out 'clicks' in an LP track.

frame

A snapshot in time making up a single picture in a video clip. For PAL systems there are 25 frames per second & 30 fps for NTSC (but a lower resolution).

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G

gamma

The range of colour values a monitor, scanner, or printer can display. Adjusting this value increases or decreases the intensity of the light spectrum. A gamma corrected image simulates the adjusted display value when it is saved. Important for getting a faithful reproduction of the original image on the chosen display device.

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H

Hertz (Hz)

The unit of frequency.

Hi8

Higher quality popular successor to Video8. To see the benefit the camcorder or player it is best to interconnect the devices with S-video cables. Capable of producing good quality video superior to VHS whilst also providing stereo sound. 

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I

import

To bring data into an application from another using a format that the receiving application understands. Quite often used when initially populating your PC Music Library with your multimedia collection. Sometimes also referred to as Syncing.

interlaced

The method by which a video picture is built up by rastering alternate horizontal lines (odd vs. even) in each frame onto the screen. Once displayed at 25 fps the eye sees the picture as one. Compare with progressive which rasters the horizontal lines in sequence.

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J

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K

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L

lossless compression (encoding)

A form of encoding where no data is lost, and therefore audio quality is maintained with a small reduction in original file size.

lossy compression

A form of compression that attempts to discard 'unnecessary' data. Taken too far, this data loss can affect the quality of the audio but greatly reduces the file size. MPEG1,2 & 4 are examples of video encoding.

lux

A measure of the light levels. Cameras capable of operating in lower lux levels produce better quality video in darker surroundings.

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M

miniDV

A popular digital video recording format on the smallest tape form factor. MiniDV can be imported directly into a PC for editing whilst maintaining the original quality perfectly.

MP3

The most popular digital audio encoding format. Originally invented in 1991 by Engineers of the Fraunhofer Society in Germany. It was designed as a lossy format to greatly reduce the amount of data required and yet still sound like the original uncompressed audio. This is achieved to differing degrees using bit rate & by discarding sounds inaudible to most listeners.

mp3 / mp4 player

The name for portable music players and so named because of the MP3 format being the most widely adopted. The recent addition of video enabled devices has spawned a new class of devices called MP4 players named after the video codec.

multimedia

The collective term used to describe the integration, & playback, of graphics, music and video.

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N

noise

White streaks or flashes observed during playback due to flaws in the original tape or poor tracking.

NTSC

(National Television Standards Committee) stands for the TV format used in the USA. PAL is the European equivalent.

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O

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P

PAL

(Phase Alternating Line) is the analogue broadcast TV standard used the majority of the World outside of USA. PAL uses 625 lines at 25 fps vs. NTSC's 525 lines at 30fps. DVDs will show which standard they are with PAL offering the higher resolution.

progressive

A video display mechanism whereby the video frame is built up by the horizontal lines in sequence (vs. interlaced). Progressive is the preferred display method for better quality pictures as it has a perceived better resolution and is less subject to flicker.

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Q

QTIF

Quick Time Format.

QuickTime

A video and animation system developed by Apple Computer and built into the Macintosh operating system and iTunes.

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R

raster

A rectangular pattern of parallel scanning lines on a TV screen or PC Monitor..

RealVideo

A widely adopted standard for streaming video & audio data across the internet.

recode

The process of reading a specific file format and encoding it again into a modified form. Uses include reducing the original bit rate (in audio or video) to reduce the file size to enable it to fit the target device e.g. MPEG2 to MP4 or DVD-9 to DVD-5 formats.

resolution

The quality and clarity of an picture, measured in horizontal lines and/or pixels for video media.

ripping

Also known as Digital Audio Extraction. The process of copying Digital audio or video data from an optical disc to a PC's hard disc. Sometimes also used to describe the digitization of analogue data e.g. LP, Cassettes or VHS tapes in a similar manner. The copied data is usually encoded into MP4, WMV, etc. to conserve storage space.

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S

sample

An audio wave, measured in bits. The more bits in a sample, the better the clarity and fidelity.

sample rate

The number of samples used per second to digitally represent a sound, measured in Hertz (Hz - cycles per second). The more samples taken per second, the more accurate the digital representation of the sound. The sample rate of an audio recording is one of the factors that determines the overall sound quality.

sample size

The size of each sample, measured in bits.

streaming

Playing an audio or video file simultaneously as it downloads from the Internet.

S-VHS or Super VHS

An improved and higher resolution VHS format. To see the benefit the camcorder or player it is best to interconnect the devices with S-video cables. Capable of producing good quality video superior to VHS whilst also providing stereo sound.

S-Video

The video signal used in higher end VHS & Video8 formats i.e. SVHS & Hi8. The signal keeps the luminance and chrominance signals separated thereby maintaining improved video integrity when compared to composite video signal. Look for a 4 pin DIN plug type connected vs. the usual Red, White & Yellow of a composite A/V cable.

syncing

The process of synchronizing the content of an MP3 player with a Media Player in a PC.  Used to copy favourite tracks from the PC to play on the portable device.

Sync

The process by which video & audio signals are co-ordinated to display simultaneous during playback.

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T

timestamp

The dates and times associated with a file or video recording.

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U

USB (Universal Serial Bus)

A computer port for connecting peripheral devices, such as mouse devices, keyboards, cameras, and scanners.

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V

VHS & VHS-C

(Video Home System) invented by JVC in Japan and the winner of the original VHS / Betamax format wars. Popular right up until the DVD which has replaced it as the format of choice for commercial video material. Original VHS camcorders were popular because tapes could be immediately played back on the home video machine. The larger size of the tape and camcorders prompted the introduction of the VHS-C (Compact) tape which shared the same benefits but in a smaller form factor.

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W

watermark

In photography it is a small semitransparent graphic added to an image, usually to provide copyright protection. The musical equivalent is a digital signature embedded into the encoded files containing the original owner's identity also to provide copyright protection.

WMV

Microsoft's proprietary compressed Windows Media A/V file format.

Windows Media Player

Microsoft's media player bundled with every copy of its operating system. Plays most formats of digital music and can be used to Rip CDs to MP3, WMA & WAV formats. Recent versions act as a Media Library & catalog Photos, Videos as well as music.

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X

XML (Extensible Markup Language)

A standard language for documents on the Web.

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Y

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Z

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