Capstan crease

Wrinkles or creases pressed into the tape by the capstan/pinch roller assembly. See Crease. [BAVC]

Carbon black

An anti-static agent added to tape binder, which also attracts debris to tape. [BAVC]


The physical medium on which the video/data is recorded. [AMIA]


A case or container, inserted into a larger piece of equipment, which is easily exchanged, for example a game cartridge in a console, or an ink cartridge in a printer. [EAI]


A list of items that records, describes, and indexes the resources of a collection, a library, or a group of libraries. [UPF]


The process of creating and arranging records that describe materials so as to facilitate identification, search and retrieval, acquisitions, circulation, preservation, rights, evaluation, and collocation. A record generally consists of a description; headings for topics, persons, places, etc.; an identification number; and links to related resources, such as authority records. Differs from a simple listing by the imposition of controlled vocabularies and by mechanisms allowing users to draw relationships between various entities. [Getty]

CAV (Constant Angular Velocity)

The disc speed remains constant while the head-to-disc speed changes. Magnetic discs spin at a Constant Angular Velocity.[AMIA]


Charged Coupled Device. "The computer chip in video cameras that converts light images into an electronic signal." [BAVC]

Cellulose diacetate.

The type of basefilm used for making audio tapes until the 1960s. It is related in chemical composition to cellulose acetate. [AMIA]


The separate color components used by various color models. By default, RGB images have three channels: red, green, and blue; CMYK images have four: cyan, magenta, yellow, and black. Extra or 'alpha' channels can be added to describe, for example, levels of transparency, or be used as masks that allow or restrict the output of color. [Getty]

Character generator

Electronic device which produces graphics and characters for creating video titles. [BAVC]


A text-based interface allowing multiple users to write messages and reply to each other in real time. Examples include ICQ and Instant Messaging. [Variable Media]


Video color, or saturation. [BAVC]

Chroma crawl

An artifact of encoded video also known as dot crawl or cross-luminance. Occurs in the video picture around the edges of highly saturated colors as a continuous series of crawling dots and is a result of color information being confused as luminance information by the decoder circuits. [BAVC]

Chroma level

A reference to amount of color saturation; high level chroma that produces pastel, washed out color; low level chroma produces heavy, saturated colors. The absence of chroma would result in black and white. [BAVC]

Chroma noise

A condition in which colors appear to be moving on screen. In color areas of picture, chroma noise is usually most noticeable in highly saturated reds. [BAVC]


Studio technique combining two video images by replacing a given chroma level from one image with the content of the other content. [Montevideo]


The color part of a signal relating to the hue and saturation, but not to the brightness or luminance of the signal. E.g., black, gray and white have no chrominance, but any colored signal has both chrominance and luminance. U,V; Cr,Cb; I,Q (R-Y, B-Y) represent the chrominance information of a signal. [BAVC]


The wrinkling, or folding over, of tape on itself in a loose tape pack. Normally occurs when a loose tape pack is stopped suddenly, causing outer tape layers to slip past inner layers, which in turn causes buckling of tape in the region of the slip. Results in large dropout or higher error rates. [BAVC]


Debris between the head and the surface of a tape will cause errors in playback. However, the term "cleaning" is sometimes used in a general way to refer to more than the removal of debris from the surface of a tape, but to the removal of products of deterioration and other actions of the "cleaning" machines. For example, it may be that one of the important functions of "cleaning" systems is to smooth deformations in the surface of the tape and this function could not correctly be described as cleaning but may be one of the actions being carried out by machines. These cleaning systems have a number of elements - contact with Pellon cloth, a vacuum chamber and a polishing stone. Research could valuably be conducted to establish what the effect of these cleaning systems are, what is being removed, the effect of the different elements and whether modifications could usefully be made. In addition to the systems described on the BAVC DVD Playback: Preserving Analog Video, there are also professionals who have skills and experience to hand clean videotape. [BAVC]

Clipping level

An electronic limit to avoid overdriving the video or audio portion of the television signal [BAVC]


In digital media, a perfect copy of a given file or files. Unlike traditional media such as analog photography or film, cloned copies are indistinguishable from the original. [Variable Media]

Closed-circuit installation

Installation consisting of one single camera and a monitor that simultaneously displays the recorded images [or live feed]..[Montevideo]

CLV (Constant Linear Velocity)

The disc changes speed as the head moves from the inner track to the outer track. Compact discs (CDs) spin at a Constant Linear Velocity. [AMIA]


(Color, Magenta, Yellow, Black) Often referred to as four-color process, CMYK is a subtractive color model, using a mix of cyan, magenta, yellow, and black inks to reproduce a range of colors. CMYK is the most basic color process used in print. [See also RGB]. [Getty]


Instructions written in a language a computer can understand and execute. Examples inlcude Java and JavaScript. [Variable Media]


A compression/ decompression (sometimes coder/decoder) algorithm or scheme that reduces the volume of bits necessary to store a data object such as an image file (compression) but that allows the reconstruction of the compressed data into a usable format for display, processing, etc. (decompression). There are many different codecs, and they are often used to minimize file transfer time in order to optimize images or data for Web use. [Getty]


The level of demagnetizing force that would need to be applied to a tape or magnetic particle to reduce the remanent magnetization to zero. A demagnetizing field of a level in excess of the coercivity must be applied to a magnetic particle in order to coerce it to change the direction of its magnetization. Coercivity is the property of a tape that indicates its resistance to demagnetization and determines the maximum signal frequency that can be recorded by a tape. Hc is the common abbreviation for coercivity. [AMIA]

Cohesive force

The force that holds a material together. [AMIA]

Color bars

Standard color test signal, displayed as rows or bars of color, used in the alignment of color video equipment. See also: NTSC Color Bars. [BAVC]

Control number

A unique number assigned to a specific element of a work.[IMAP]


A strict version of the free software license that requires any modification of the original code to remain free software. For example, programmers who base a product on copylefted code cannot hide the source code from other users. The most common example of a copyleft license is Richard Stallman's GPL (GNU General Public License). [Variable Media]


A tape deformity, which may cause horizontal or vertical lines in the playback picture. See wrinkle. [BAVC]