Glossary 0-B

3GP An MPEG video format for use in mobile terminals (such as cell phones).
3ivX An MPEG-4 “toolkit” that can support MPEG-4 video, MPEG-4 audio and MP4 files.
4:1:1 A color sampling ratio of digitized video signals used by DV, DVCAM and DVCPRO25. 4:1:1 = Luminance:R – Y:B – Y (the red and blue channels are transmitted at one-fourth the bandwidth of the luminance channel).
4:2:2, 4:4:4 and 4:4:4:4 Color sampling ratios for digitized video signals:

  • 4:2:2 = Luminance:R – Y:B – Y (the red and blue channels are transmitted at half the bandwidth of the luminance channel; this ratio has been used in broadcast television for years)
  • 4:4:4 = Luminance:R – Y:B – Y (all three channels are transmitted at the same bandwidth; this ratio is used for computer graphics)
  • 4:4:4:4 = Luminance:R – Y:B – Y:key channel (all three channels are transmitted at the same bandwidth along with a fourth key channel)
4:3 Aspect ratio of most analog television screens. In order to show wider 16:9 movies on these screens, the picture is either cropped (pan & scan) or shown with black bars above and below (letterbox).
5.1 Audio Sometimes called 5.1 Channel Surround Sound, it is a sound system made up of five separate audio channels (left, middle, right, rear left, rear right) and one subwoofer channel for low-frequency effects (LFEs). Without the subwoofer channel, the sound is called 5.0.
525/60 The NTSC television standard: 525 scanned lines per frame and 60 interlaced fields (or 30 frames) per second. In actuality, the standard is 29.97 frames per second, but 30 is used for shorthand.
6.1 Channel Surround Sound An extension of 5.1 Channel Surround Sound, also called DTS Surround EX. The change from 5 to 6 represents the addition of a new channel: back surround, or rear center.
625/50 The PAL/SECAM television standard: 625 scanned lines per frame and 50 interlaced fields (or 25 frames) per second.
7.1 Channel Surround Sound An extension of 6.1 Channel Surround Sound, also called DTS THX Surround EX. The sixth channel added in 6.1 is split into two channels: back left and back right.
16:9 Widescreen/letterbox ratio, as opposed to “standard” 4:3.
A
AAC Advanced Audio Coder. An audio-encoding standard for MPEG-2; it is not compatible with the older MPEG-1 audio.
Aberration A focusing error in the laser of a CD or DVD player, causing the disc to be misread.
AC3 A compressed audio signal used on NTSC-formatted DVDs, providing up to six separate channels of digital sound (file extension: .ac3). Also called the Dolby Digital Surround Sound System.
AES/EBU Interface The digital audio signal transmission standard created by the Audio Engineering Society and the European Broadcasting Union. This is the professional version of the standard; there is a consumer version called S/PDIF.
AIFF Audio Interchange File Format (file extensions: .aif, .aifc, .aiff). An audio format created by Apple Computer.
Aliasing A distortion caused by improper waveform reconstruction during the reproduction of an audio or video signal. Aliasing creates “noise” that is not in the original signal.
Amplifier A device that provides power to a signal, such as powering speakers in a home audio or theater system.
Anamorphic A wide video image (16:9) that has been “squeezed” horizontally so that it can be shown on a standard 4:3 television screen. When viewed on a wide-screen television, the image can expand to its regular proportions. Many DVDs have an option allowing viewers to choose a letterbox or pan & scan version of a movie if they are using a 4:3 screen.
Angle When a scene in a video is recorded from different viewpoints, each viewpoint is called an angle. DVDs that have multiple angles (angle blocks) recorded allow a viewer to choose which angle they wish to view a scene from.
Antialiasing Smoothing out the sharp edges of text or graphics by mixing colors along the edge.
Artifact A problem with video playback caused by an error in the duplication of the original signal. These can include flickering images, pixelated images, skipping and color shifting.
Aspect Ratio The width-to-height ratio of an image. Two common aspect ratios are those of TV screens (4:3) and wide screens (16:9).
ASPI Advanced SCSI Programmer’s Interface. This is a layer of software code that allows programs to communicate with SCSI and ATAPI devices, such as CD or DVD drives.
ASV Audio Still Video. A still picture on a DVD-Audio disc.
ASX Advanced Stream Redirector (file extension: .asx). A text file that contains server and media information, similar to Windows Media Redirector files (file extension: .wvx).
ATA Advanced Technology Attachment (sometimes called Parallel ATA or IDE). A disk drive implementation that integrates the controllers on a drive. There are several versions of ATA, such as ATA-2 (EIDE) and Ultra-ATA (Ultra-DMA, ATA-33 or DMA-33).
ATAPI Advanced Technology Attachment Packet Interface. An interface that supports CD and DVD drives using a computer’s ATA (IDE/EIDE) connections. ATAPI makes it possible to connect devices other than hard drives via ATA.
A-Time Absolute Time. Time elapsed since the beginning of a disc.
ATSC Advanced Television Systems Committee, Inc. An international organization that develops voluntary standards for digital television and coordinates TV standards across different media, such as digital television, interactive systems, broadband multimedia, HDTV and satellite broadcasting.
Audio Frequency Sound frequencies within the range of human hearing, roughly 20 Hz–20 kHz.
Audio Streams Different audio tracks (up to eight) that can be recorded on the same DVD. Usually used for foreign language tracks and director’s commentary tracks.
AUDIO_TS Universal Disc Format file name used for the DVD-Audio directory on a DVD disc.
Author Formatting video so it can be either burned onto a disc or streamed across the Internet.
Authoring Creating an application or video to be stored on disc, such as a game or a multimedia presentation.
Auto-Insert Notification A Windows feature that automatically starts an application or an audio/video player when an appropriate disc is inserted into a computer’s CD or DVD drive.
AVC Advanced Video Codec. A new MPEG-4 standard, one of the best video coding formats available.
Average Bit Rate DVD uses variable bit rates in order to optimize a disc’s storage capacity; average bit rate is a measure of volume of data accessed over time, usually in kilobytes per second (kbps).
AVI Audio Video Interleaved. A file format for storing sound and moving pictures in Microsoft’s RIFF format (file extension: .avi).
B
B Frame Bi-directional frame. A type of MPEG picture created by comparing the differences between the frames before and after it. See I Frame, P Frame.
Bandwidth The amount of data that can be transferred or processed in a specific unit of time. Also used to describe the range of frequencies a device operates within; wider bandwidth (measured in kHz) usually means better performance.
Barcode A unique code printed in the clear inner ring of a disc.
Bass The lowest audible sound frequencies, roughly 20 Hz–160 Hz.
BIN/CUE A CD image format: .CUE files contain VCD, SVCD or other data track layout information; .BIN files contain the actual data.
Bit A binary digit. 0 is “off” and 1 is “on.”
Bit Rate (or Data Rate) The amount of data processed during a specific time period, usually expressed in bits per second (bps) or kilobits per second (kbps). Higher bit rates produce higher quality sound/video, but also create larger file sizes. A typical MP3 audio file has a bit rate of 128 kbps, while a DVD video file runs around 4500 kbps.
Bitmap An array of pixels, or an image made up of these pixels.
Bits per Pixel The number of bits used to represent a pixel’s color. A single bit per pixel only permits 21, or 2 colors (black and white); 24 bits per pixel allow for 224, or 16,777,216 colors.
Bit Setting A small group of bits found at the beginning of a DVD which identify what type of DVD it is: DVD-ROM, DVD+R or DVD+RW.
Bitstream A data stream which is processed sequentially, like Dolby Digital sound on a DVD.
Block An eight-by-eight two-dimensional array of elements, either adjacent luminance/chrominance samples or Discrete Cosine Transform (DCT) coefficients.
Blue Book The official formatting standard for CD Extra (CD Plus) discs.
Blue Screen (or Chroma Key) Process When shooting a video, all images at a set luminance level are removed (or “keyed out”) and replaced with another image. A common example is a meteorologist on TV that appears to be standing in front of an interactive weather map. The blank wall he/she is actually standing in front of is all one luminance level; this is the level that is keyed out and replaced with the image of the map.
Blu-Ray Disc The newest disc format (developed by Sony, Matsushita and Philips) which can hold 23–30 GB of data per layer. This is equivalent to about four hours of high-definition video.
Bonded Disc Refers to the physical structure of a DVD disc: it is made of two 0.6 mm-thick layers bonded together.
Bootable A disc or other storage media which contains all the operating system software a computer needs in order to run.
Bootleg To illegally produce, distribute, or sell media. Also refers to the product itself: a bootleg DVD.
bps Bits per second. See bit rate.
Brightness A pixel’s value along a black-to-white scale.
Buffer Computer memory that temporarily stores data to compensate for different data transfer rates between two devices.
Buffer Underrun An error caused in the CD or DVD burning process where the recorder’s internal memory buffer fails to handle a long interruption or becomes completely empty. This usually results in a bad burn, creating an unusable disc.

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