0-9 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
 
Name Description
16x9 A wide screen television format in which the aspect ratio of the screen is 16 units wide by 9 high as opposed to the 4x3 of normal TV.
24-bit color Color for which each red, green, and blue component stores 8 bits of information. 24-bit color is capable of representing over one million different variations of color.
2:3 pulldown  See pulldown. 
2K An image scanned into a computer file at a resolution of 2048 horizontal pixels.
3:2 pulldown The technique used to convert 24 frames per second film to 30 frames per second video. Every other film frame is held for 3 video fields resulting in a sequence of 3 fields, 2 fields, 2 fields, etc. 
4 fsc Composite Digital video as used in D2 and D3 VTRs. Stands for 4 times the Frequency of Subcarrier, which is the sampling rate used.
4:2:2 The sampling ratio used in the D1 (CCIR 601) digital video signal. For every 4 samples of luminance there are 2 samples each of R-Y (Red minus Luminance) and B-Y (Blue minus luminance).
4:3 The aspect ratio of conventional video, television, and computer screens.
4:4:4 A sampling ratio that has equal amounts of the luminance and both chrominance channels.
4K An image scanned into a computer file at a resolution of 4096 pixels. 4 K is considered to be a full-resolution scan of 35mm film.
8mm A compact videocassette format that uses magnetic tape and is eight millimeters wide. 8mm is a world-wide standard and offers high-quality recording and playback of video and audio. 
A and B cutting A method of assembling original material in two separate rolls, allowing optical effects to be made by double printing ( A and B Printing).
a-frame edit A video edit which starts on the first frame of the 5 video frame (4 film frame) sequence created when 24 frame film is transferred to 30 frame video (see 3:2 pulldown). The A-frame is the only frame in the sequence where a film frame is completely reproduced on one complete video frame. Here is the full sequence (The letters correspond to film frames.) A-frame=video fields 1&2, B-frame= video fields 1&2&1, C-frame=video fields 2&1, D-frame=video fields 2&1&2.
A-mode  A linear method of assembling edited footage. In A-mode, the editing system performs edits in the order in which they will appear on the master, stopping whenever the edit decision list (EDL) calls for a tape that is not presently in the deck. See also B-mode, C-mode, D-mode, E-mode, source mode. 
a-mode edit An editing method where the footage is assembled in the final scene order. Scene 1, scene 2, ...
A-roll  A method of conforming that requires the compositing of all multilayer effects into a single layer (including laboratory-standard dissolves and fades) before assembly. Also called single-strand editing. 
A-to-D converter An electronic device that converts analog signals to digital. An A-to-D converter is an integral part of digital-video-related technology.
A/B roll Typically, A/B roll is an editing technique where scenes or sounds on two source reels (called roll A and roll B) are played simultaneously to create dissolves, wipes, and other effects. On nonlinear editing systems, A/B roll refers to using two source streams (.avi, .wav, .tga, and so on) to create an effect.
A/B-roll linear editing Recording edits from two video sources, such as two VCRs to a third, to achieve transition effects. See also, B-roll
A/D converter  Analog-to-digital converter. A device that transforms a continuously variable (analog) signal to discrete binary bits that represent digital samples of the original signal. 
A/V drive Audio/video drive; a high-end hard drive capable of storing high-bandwidth (i.e., high data rate) audio/video data. 
AC'97, AC'98 These are definitions by Intel for the audio I/O implementation for PCs. Two chips are defined: an analog audio I/O chip and a digital controller chip. The digital chip will eventually be replaced by a software solution. The goal is to increase the audio performance of PCs and lower cost. 
AC Coupled AC coupling passes a signal through a capacitor to remove any DC offset, or the overall voltage level that the video signal "rides" on. One way to find the signal is to remove the DC offset by AC coupling, and then do DC restoration to add a known DC offset (one that we selected). Another reason AC coupling is important is that it can remove large (and harmful) DC offsets. 
academy  Pertaining to specifications that meet the Academy of Motion Picture Arts and Sciences standards, such as academy leader, academy format (for film stock), academy countdown, and so forth. 
access time The length of time it takes to find, retrieve, and display digital information.
active picture area The part of a TV picture that contains actual picture as opposed to sync or other data. Vertically the active picture areas is 487 lines for NTSC and 576 lines for PAL. The inactive areas is called blanking.
ADC, A/D Analog-to-Digital Converter. This device is used to digitize audio and video. An ADC for digitizing video must be capable of sampling at 10 to 150 million samples per second (MSPS). 
add edit  An edit added between consecutive frames in a sequence segment within the Timeline. An add edit separates segment sections so the user can modify or add effects to a subsection of the segment. 
additive colour Colour mixture by the addition of light of the three primaries, red, green, and blue.
additive mix A mixing process that adds the colour value of a pixel in one source clip to the value of a corresponding pixel in a second source clip, and assigns the resulting value to the corresponding pixel in the output clip.
ADR  1. Automatic display replacement. The process of looping playback of a selected region in a sequence and automatically recording multiple replacement takes. 2. Automatic dialog replacement in film. Also called dubbing
advance The separation between a point on the sound track of a film and the corresponding picture image.
Advanced Television Systems Committee (ATSC) The group that recommended the new digital television standards to the FCC. They defined the SDTV and HDTV standards for the United States, using MPEG-2 for video and Dolby Digital for audio. Other countries are also adopting the ATSC HDTV standard. 
AES  Audio Engineering Society. The primary international organization of users and producers of professional audio. The AES maintains a standards committee that supervises the work of several subcommittees and working groups covering various fields of sound reinforcements. 
AES/EBU The digital audio standard set by the Audio Engineering Society and European Broadcast Union and used by most forms of digital audio from CDs to D1.
AFM Abbreviation for audio frequency modulation; the most common form of audio recording found in most consumer and professional video recording decks, especially in VHS and 8mm recorders. AFM audio is limited in dynamic range and frequency response, and can include stereo and multi-track audio.
AIFF Audio Interchange File Format. This is the format for both compressed and uncompressed audio data.
AIFF-C  Audio Interchange File Format-Condensed. A sampled-sound file format that allows for the storage of audio data. This format is primarily used as data interchange format but can be used as a storage format as well. OMF Interchange includes AIFF-C as a common interchange format for noncompressed audio data. 
aliasing Defects in the picture caused by too low a sampling frequency or poor filtering. Usually seen as "jaggies" or stair steps in diagonal lines.
alpha channel The fourth channel of a 32-bit RGB image that creates transparency in the image. The other three channels are red, green, and blue. 
Alpha Mix This is a way of combining two images. How the mixing is performed is provided by the alpha channel. The little box that appears over the left-hand shoulder of a news anchor is put there by an alpha mixer. Wherever the little box is to appear, a "1" is put in the alpha channel. Wherever it doesn't appear, a "0" is used. When the alpha mixer sees a "1" coming from the alpha channel, it displays the little box. Whenever it sees a "0", it displays the news anchor. Of course, it doesn't matter if a "1" or a "0" is used, but you get the point. 
ambient Natural, or surrounding light in a clip.
American Standard Code for Information Interchange, (ASCII) Unformatted text characters that are interchangeable across platforms and applications. Also referred to as "plain text".
Ampex Digital Optics, (ADO) Trade name for digital effects system manufactured and sold by Ampex.
amplitude The maximum distance an oscillating body (e.g., a pendulum) or wave travels from a mean point.
Amplitude Modulation, (AM) A method of encoding data onto a carrier, such that the amplitude of the carrier is proportional to the data value. 
 
analog Analog information is represented electronically as a continuously varying electronic signal.
analog recording  The common form of magnetic recording where the recorded waveform signal maintains the shape of the original waveform signal. All videotape source footage is analog. When recorded or digitized (via telecine transfer), footage is converted from the analog format to a digital format. 
analog video A video signal made of a continuous electrical signal. Your television and VCR can be analog video devices. To be stored and manipulated on a computer, analog video must be converted to digital video.
anamorphic Distortion in viewing of images or geometry related to the difference between computer monitor screen aspect ratio (in which pixels are square) and broadcast, projected or frame aspect ratio (in which image pixels are wider than they are high).
Ancillary Timecode, (ATC) BT.1366 defines how to transfer VITC and LTC as ancillary data in digital component interfaces. 
animatic Limited animation consisting of art work shot and edited to serve as a video tape storyboard. Commonly used for test commercials.
animation The recording of a sequence of still artwork or objects in a way that makes them appear to move on film or video. 24 fps is considered the appropriate speed for animation.
animation curve A curve depicting the interpolation between the various keyframes.
answer Smoothing, removing, or reducing jagged edges along the lines and curves in text, images, or geometry.
answer print The first print combining picture and sound submitted by the laboratory for the customers' approval.
Anti-Alias Filter A lowpass filter used to bandwidth-limit a signal to less than one-half the sampling rate. 
anti-aliasing A technique that smooths jagged edges in computer-generated text or graphics. The manipulation of edges (e.g., those between areas with contrasting colors) in an image, graphic, or text to make the edges appear smoother. Anti-aliased edges appear blurred up close but smooth at normal viewing distance. Anti-aliasing is important when working with high-quality graphics for television use. Contrast with aliasing.
aperture The opening which allows light to pass through a camera lens. An adjustable diaphragm is used to control the size of the opening. 

Effective Aperture
An adjustable diaphragm is used to control the size of the opening. The apparent diameter of a lens viewed from the position of the object against a diffusely illuminated background, such as a sky. 

Picture Aperture 
The rectangular opening in a metal plate at which each frame of the motion picture film is situated during exposure, printing or projection. 

Relative aperture 
The ratio of the focal length of a lens to its effective aperture for an object located at infinity.

Aperture Delay Aperture delay is the time from an edge of the input clock of the ADC until the time the ADC actually takes the sample. The smaller this number, the better. 
Aperture Jitter The uncertainty in the aperture delay. This means the aperture delay time changes a little bit each time, and that little bit of change is the aperture jitter. 
architecture In digital video, architecture (sometimes also known as format) refers to the structure of the software responsible for creating, storing, and displaying video content. A architecture may include such things such as compression support, system extensions, and browser plug-ins. Different multimedia architectures offer different features and compression options, and store video data in different file formats. QuickTime, RealVideo, and MPEG are examples of video architectures (though MPEG is also a type of compression). 
Artifacts A side effect in video or audio caused by signal processing. In the video domain, artifacts are blemishes, noise, snow, spots, whatever. When you have an image artifact, something is wrong with the picture from a visual standpoint. Don't confuse this term with not having the display properly adjusted. For example, if the hue control is set wrong, the picture will look bad, but this is not an artifact. An artifact is some physical disruption of the image. 
ASA Exposure Index or speed rating that denotes the film sensitivity, defined by the American National Standards Institution. Actually defined only for black-and-white films, but also used in the trade for colour films.
Aspect Ratio The ratio of the width of the picture to the height. Displays commonly have a 4:3 or 16:9 aspect ratio. Program material may have other aspect ratios (such as 20:9), resulting in it being "letterboxed" on the display. 
aspect ratio  The numerical ratio of a viewing area's width to its height. In video and television, the standard aspect ratio is 4:3, which can be reduced to 1.33:1 or simply 1.33. HDTV video format has an aspect ratio of 16:9. In film, some aspect ratios include: 1.33:1, 1.85:1, and 2.35:1. 
assemble edit Adding material that has a different signal to the end of a pre-recorded section of a video tape. Adding an assemble edit to the middle of an existing segment causes an abrupt and undesirable change in the sync of the video signal. Contrast with insert edit.
asynchronous When digital communication (e.g., that between computers) is not synchronized by a mutual timing signal or clock.Refers to circuitry without a common clock or timing signal. 
ATM  Asynchronous transfer mode. A network technology based on transferring data in packets of a fixed size. The packet used with ATM is relatively small compared to units used with older technologies. The small, constant packet size allows ATM equipment to transmit video, audio, and computer data over the same network and ensures that no single type of data ties up the line. Current implementations of ATM support data transfer rates of 25 to 622 Mb/s (megabits per second). This compares to a maximum of 100 Mb/s for Ethernet, the current technology used for most local area networks (LANs). 
ATR  Audiotape recorder. A device for recording and reproducing sound on magnetic recording tape. 
ATSC Advanced Television Systems Committee. They defined the SDTV and HDTV standards for the United States, using MPEG-2 for video and Dolby Digital for audio. Other countries are also adopting the ATSC HDTV standard. 
ATSC A/49 Defines the ghost cancellation reference signal for NTSC. Download the specification. 
ATSC A/52 Defines the (Dolby Digital) audio compression for ATSC HDTV. Download the specification. 
ATSC A/53, A/54 Defines ATSC HDTV for the USA. Download the A/53 and A/54 specifications. 
ATSC A/57 Defines the program, episode, and version ID for ATSC HDTV. Download the specification. 
ATSC A/63 Defines the method for handling 25 and 50 Hz video for ATSC HDTV. Download the specification. 
ATSC A/65 Defines the program and system information protocol (PSIP) for ATSC HDTV. Download the specification. 
ATSC A/70 Defines the conditional access system for ATSC HDTV. Download the specification. 
ATSC A/90 Defines the data broadcast standard for ATSC HDTV. Download the specification. 
ATSC A/92 Defines the IP multicast standard for ATSC HDTV. Download the specification. 
attenuation A decrease in an electrical signal's amplitude.
Attic folder  The folder containing backups of your files or bins. Every time you save or the system automatically saves your work, copies of your files or bins are placed in the Attic folder, until the folder reaches the specified maximum. The Attic folder copies have the file name extension .bak and a number added to the file name. The number of backup files for one project can be changed (increased or decreased) in the Bin Settings dialog box. 
attribute clip  A mechanism that applications can use to store supplemental information in a special track that is synchronized to the other tracks in a track group. 
audio effects board Similar to a switcher, an audio effects board is the primary router and mixer for source audio, and for adjusting, mixing, and filtering audio. Usually, a digital audio workstation is used to perform more complex audio work.
Audio Modulation Refers to modifying an audio subcarrier with audio information so that it may be mixed with the video information and transmitted. 
audio scrub  See scrubbing. 
Audio Subcarrier A specific frequency that is modulated with audio data. 
audio subframe There are 100 subframes of audio for every frame of video.
audio sweetening  The mixing of sound effects, music, and announcer audio tracks with the audio track of the edited master tape, usually during the mixing stages of a production. Also called audio postproduction for video. 
audio timecode  Longitudinal timecode (LTC) recorded on an audio track. 
AudioVision  A registered trademark of Avid Technology, Inc. A digital, nonlinear audio editing system that locks digital video in sync with audio for audio editing and sweetening. 
auto-assembly The automatic assembling of an edited video tape on a computerized editing system (controller), based on an edit decision list (EDL). Auto-assembly is used in assemble editing.
Automatic Frequency Control (AFC) A technique to lock onto and track a desired frequency. 
Automatic Gain Control, (AGC) A circuit that automatically adjusts audio or video input levels.
AutoSave  A feature that saves your work at intervals you specify. Backups are placed in the Attic folder. 
AUX  Auxiliary track. In a video editing system, a channel reserved for connecting an external audio device, video device, or both. 
AV Abbreviation for audiovisual; the making use of or relating to both hearing and sight and to electronic media in general.
AVI Abbreviation for Audio-Video Interleaved; the algorithm created by Microsoft for synchronizing and compressing analog audio and video signals. AVI is also the file format used by Video for Windows
Avid disk  The disk on the Macintosh platform that contains the operating system files. The computer needs operating system information in order to run. 
Avid Projects folder  The folder containing your projects. 
AVR  Avid Video Resolution. The compression level at which visual media is stored by the Avid system. The system creates media in a particular AVR using proprietary conversion algorithms to convert analog video to digital form.
axis the component of an object that you use to determine its two or three dimensional space and movement.
B'-Y' The blue-minus-luma signal, also called a color difference signal. When added to the luma (Y') signal, it produces the blue video signal. 
b-frame Bi-directional frame. The frame in an MPEG sequence created by comparing the difference between the current frame and the frames before and after it.
B-mode  "A ""checkerboard"" or nonsequential method of assembly. In B-mode, the edit decision list (EDL) is arranged by source tape number. The edit system performs all edits from the tapes currently assigned to decks, leaving gaps that will be filled by material from subsequent reels. See also A-mode, C-mode, D-mode, E-mode, source mode. "
b-mode edit An editing method where the footage is assembled in the order it appears on the source reels. Missing scenes are left as black holes to be filled in by a later reel. Requires fewer reel changes and generally results in a faster edit session.
B-roll Refers to secondary or duplicated footage of a fill or secondary nature usually played from the B source player in an A/B-roll linear editing system. B roll does not refer to all tapes played from the B source player.
backplane PCB (printed circuit board) on a Movie-2 bus connector.
backtiming  A method of calculating the IN point by subtracting the duration from a known OUT point so that, for example, music and video or film end on the same note. 
backup  A duplicate copy of a file or disk in another location if the original file or disk becomes corrupted. See also Attic folder. 
balanced cable In audio systems, typically refers an a specific cable configuration that cancels induced noise.
Bandpass Filter A circuit that allows only a selected range of frequencies to pass through. 
Bandwidth (BW) The range of frequencies a circuit will respond to or pass through. It may also be the difference between the highest and lowest frequencies of a signal. 
Bandwidth Segmented Orthogonal Frequency Division Multiplexing BST-OFDM attempts to improve on COFDM by modulating some OFDM car­riers differently from others within the same multiplex. A given transmission channel may therefore be "segmented", with different segments being modu­lated differently. 
bar code  A pattern of vertical stripes of varying width and spacing that encodes information. Bar codes can be used to encode timecode on film. 
base board Printed circuit board (and mounted components such as integrated cirucuits, etc.) that is inserted into the computer's expansion slot. A module board isoften attached to the base board.
Baseband When applied to audio and video, baseband means an audio or video signal that is not modulated onto another carrier (such as RF modulated to channel 3 or 4 for example). In DTV, baseband also may refer to the basic (unmodulated) MPEG stream. 
batch capture The automated process of capturing clips in a list. (see batch list) 
batch digitize  The automated process in which groups of clips, sequences, or both are digitized (recorded digitally). 
batch list A list of clips to be batch captured. 
batch record  The automated process in which groups of clips, sequences, or both are digitized (recorded digitally). 
baud  The number of electrical oscillations that occur each second. Baud was the prevalent measure for bandwidth or data transmission capacity, but bps (bits per second) is used most often now and is more accurate. 
BBC British Broadcasting Corporation. 
beam the directed flow of bombarding electrons in a TV picture tube.
beam-splitter prism The optical block in a video camera onto which three CCD sensors are mounted. The optics split the red, green and blue wavelengths of light for the camera.
Bento  A registered trademark of Apple Computer, Inc. A general container format and software API (application programming interface). Bento is used by OMF Interchange as a storage and access system for the information in an OMF Interchange file. 
best light  A telecine transfer performed with optimum settings of the color grade controls but without precise scene-by-scene color correction. 
Betacam, Betacam SP  Trademarks of Sony Electronics, Inc. Two component videotape and video recording standards. Sony Betacam was the first high-end cassette-based system, recording video onto 1/2-inch magnetic tape. The SP version arrived 3 years after the first Betacam, improving on signal-to-noise ratios, frequency responses, the number of audio channels, and the amount of tape available on cassettes. SP is now the only type sold. 
bezier A curve that connects the vertices of a polygon; each vertex has two tangents, or handles, which you can use to adjust the slope of the adjacent curve or side of a polygon.
bi-phase Electrical pulses from the tachometer of a telecine, used to update the film footage encoder for each new frame of film being transferred.
bicubic surface A surface that you can add to a layer with four control handles that you can use for four-point tracking.
bid sheet A written estimate, or quote, for video or production services.
bilinear surface A surface that you can add to a layer with more than four control handles for creating non-linear effects.
bin  A database in which master clips, subclips, effects, and sequences are organized for a project. Bins provide database functions to simplify organizing and manipulating material for recording, digitizing, and editing. 
BIOS Basic Input/Output System settings for system components, peripherals, etc. This information is stored in a special battery-powered memory an is usually accessible for changes at computer start-up.
bit One binary digit. An eight-bit byte can define 256 brightness or colour values.
bit rate The amount of data transported in a given amount of time, usually defined in Mega (million) bits per second (Mbps). Bit rate is one means used to define the amount of compression used on a video signal. Uncompressed D1 has a bit rate of 270 Mbps. Mpeg 1 has a bit rate to 1.2 Mbps. HDTV has a bit rate of 1.5Gbps (giga bits per second).
bit stream A continuous series of bits, commonly used to describe a large file such as MPEG video that is read as a stream instead of all at once.
BITC Burned-In Time Code. The timecode information is displayed within a portion of the picture, and may be viewed on any monitor or TV. 
bitmap A pixel-by-pixel description of an image. Bitmap images are also referred to as raster images.
black and code  Video black, timecode, and control track that are prerecorded onto videotape stock. Tapes with black and code are referred to as striped or blacked tapes. 
black box A term used to describe a piece of equipment dedicated to one specific function.
black burst  A video signal that has no luminance or chrominance components (except burst) but contains all the other elements of a video signal. Black burst is the reference signal commonly used for timing audio and video samples. An electronic device that emits a signal that registers as pure black when recorded on videotape. 
black edits  1. A video source with no image. 2. A special source you can fade into, out of, or use for other effects.
Black Level This level represents the darkest an image can get, defining what black is for a particular video system. If for some reason the video goes below this level, it is referred to as blacker-than-black. You could say that sync is blacker-than-black. 
black point  The luminance value in a video image that you set to be equal to reference black when making a color adjustment. Compare with white point. 
black stripe See striping.
blacked tapes  See black and code. 
blackout The fading of a video signal to black to indicate, for example, the end of a show.
blanket fee Typically used for musical selections. One who pays a blanket fee has permission to use the musical selection the fee covers in an unlimited number of released projects and videos. 
blanking Portions of the video signal during which both camera and receiver complete a scan line (horizontal blanking) or field (vertical blanking), and retrace to begin the next scan. Blanking is the part of the video signal that contains no picture information. This is the time that the scanning beam in a TV picture tube is blanked to allow it to track back to the beginning without drawing diagonal lines across the screen.
blanking level The level of a video signal separating the range that contains synchronizing information from the range that contains picture information. Also known as a pedestal. 
bleach 1. Converting a metallic silver image to a halide or other salt which can be removed from the film with hypo. When bleaching is not carried to completion, it is called reducing. 2. Any chemical reagent that can be used for bleaching.
Blooming This is an effect, sometimes caused when video becomes whiter-than-white, in which a line that is supposed to be nice and thin becomes fat and fuzzy on the screen. 
blue screen  A special effects procedure in which a subject is photographed in front of a uniformly illuminated blue or green background. A new background image can be substituted for the blue or green during the shoot or in postproduction through the use of chroma key. 
BNC connector Standard twist-connector for attaching coaxial cable to professional video equipment.
bps  Bits per second. The standard measure of data transmission speeds. 
break-down The separation of a roll of camera original negative into its individual scenes.
Breezeway That portion of the video waveform between the trailing edge of horizontal sync and the start of color burst. 
brightness (1) The intensity of a color as determined on a scale from black (no brightness) to white (maximum brightness). The combination of brightness, hue, and saturation determines the appearance of the colors of a polychromatic image, whereas the brightness alone determines the appearance of a monochromatic image's color. (2) The luminance of a video signal. (3) The brightness of a monitor or video projector measured in lumens.
broadcast monitor Television set without receiving circuitry, wired directly to a VTR or other output device.
broadcast quality A quality standard for composite video signals set by the NTSC and conforming to FCC rules. If you plan to record video signal or videotape for broadcast, it is important to note that devices providing NTSC signals do not necessarily meet FCC broadcast standards.
BS.707 This ITU recommendation specifies the stereo audio specifications (Zweiton and NICAM 728) for the PAL and SECAM video standards. Purchase the specification. 
bspline A smooth curve that passes on the inner side of the vertices of a polygon to connect the vertices to interpolate or draw the polygon. 2. A curve used to define a motion path.
BST-OFDM See Bandwidth Segmented Orthogonal Frequency Division Multiplexing. 
BT.1119 Defines the widescreen signaling (WSS) information for NTSC and PAL video signals. For (B, D, G, H, I) PAL systems, WSS may be present on line 23, and on lines 22 and 285 for (M) NTSC. Purchase the ITU specification. 
BT.1124 Defines the ghost cancellation reference (GCR) signal for NTSC and PAL. Purchase the specification. 
BT.1197 Defines the PALplus standard, allowing the transmission of 16:9 programs over normal PAL transmission systems. Purchase the specification. 
BT.1302 Defines the transmission of 16:9 BT.601 4:2:2 YCbCr digital video between pro-video equipment. It defines a parallel interface (8-bit or 10-bit, 36 MHz) and a serial interface (360 Mbps). Purchase the specification. 
BT.1303 Defines the transmission of 16:9 BT.601 4:4:4:4 YCbCrK and RGBK digital video between pro-video equipment. Two parallel interfaces (8-bit or 10-bit, 36 MHz) or two serial interfaces (360 Mbps) are used. Purchase the specification. 
BT.1304 Specifies the checksum for error detection and status for pro-video digital interfaces. Purchase the specification. 
BT.1305 Specifies the digital audio format for ancillary data for pro-video digital interfaces. Purchase the specification. Also see SMPTE 272M. 
BT.1358 720 x 480 (59.94 Hz) and 720 x 576 (50 Hz) 4:2:2 YCbCr pro-video progressive standards. Purchase the specification. Also see SMPTE 293M. 
BT.1362 Pro-video serial interface for the transmission of BT.1358 digital video between equipment. Two 270 Mbps serial interfaces are used. Purchase the specification. 
BT.1364 Specifies the ancillary data packet format for pro-video digital interfaces. Purchase the specification. Also see SMPTE 291M. 
BT.1365 Specifies the 24-bit digital audio format for pro-video HDTV serial interfaces. Purchase the specification. Also see SMPTE 299M. 
BT.1366 Specifies the transmission of timecode as ancillary data for pro-video digital interfaces. Purchase the specification. Also see SMPTE 266M. 
BT.1381 Specifies a serial digital interface-based (SDI) transport interface for compressed television signals in networked television production based on BT.656 and BT.1302. Purchase the specification. 
BT.470 Specifies the various NTSC, PAL, and SECAM video standards used around the world. SMPTE 170M also specifies the (M) NTSC video standard used in the United States. BT.470 has replaced BT.624. Purchase the specification. 
BT.601 720 x 480 (59.94 Hz), 960 x 480 (59.94 Hz), 720 x 576 (50 Hz), and 960 x 576 (50 Hz) 4:2:2 YCbCr pro-video interlaced standards. Purchase the specification. 
BT.653 Defines the various teletext standards used around the world. Systems A, B, C, and D for both 525-line and 625-line TV systems are defined. Purchase the specification. 
BT.656 Defines a parallel interface (8-bit or 10-bit, 27 MHz) and a serial interface (270 Mbps) for the transmission of 4:3 BT.601 4:2:2 YCbCr digital video between pro-video equipment. Purchase the specification. Also see SMPTE 125M. 
BT.709 This ITU recommendation specifies the 1920 x 1080 RGB and 4:2:2 YCbCr interlaced and progressive 16:9 digital video standards. Frame refresh rates of 60, 59.94, 50, 30, 29.97, 25, 24, and 23.976 Hz are supported. Purchase the specification. 
BT.799 Defines the transmission of 4:3 BT.601 4:4:4:4 YCbCrK and RGBK digital video between pro-video equipment. Two parallel interfaces (8-bit or 10-bit, 27 MHz) or two serial interfaces (270 Mbps) are used. Purchase the specification. 
BTSC This EIA TVSB5 standard defines a technique of implementing stereo audio for NTSC video. One FM subcarrier transmits a L+R signal, and an AM subcarrier transmits a L-R signal. 
bug An error in a computer program.
bump-up Copying from one recording medium onto another that is more suitable for post-production purposes because, for example, it offers better bandwidth or timecode capabilities.
bumping up  The transfer of a program recorded on a lower quality videotape to a higher quality videotape (such as from 3/4-inch to 1-inch videotape, or S-VHS to MII). 
burn-in  A visible timecode permanently superimposed (burned in) on footage, usually in the form of white numbers in a black rectangle. Burned-in timecode is normally used for tracking timecode during previews or offline editing. A videotape with burn-in is also called a burn-in dub or window dub. 
burn-in-dub A duplicate of an original or master tape that includes the time code reference on-screen and is used as a reference for logging and locating scenes.
burnt-in timecode Time code numbers that are superimposed on the picture, generally created using the overlay feature of a VTR. Used for rought-cut and edit-list processing. Also called burn in.
burst The part of the sync signal that controls the hue and color accuracy of television pictures. 
Burst Gate This is a signal that tells a video decoder where the color burst is located within the scan line. 
bus 1. Electrical signal path between different physical connection points. 2. System bus on computers, represented by the expansion slot connectors. 3. Movie-2 bus.
BVB  Black-Video-Black. A preview mode that displays black, newly inserted video, and then black again. 
byte A sequence of bits. In general, the amount of memory needed for one character (for example, the letter A) of a specified size, usually 8 or 16 bits.
C-mode  A nonsequential method of assembly in which the edit decision list (EDL) is arranged by source tape number and ascending source timecode. See also A-mode, B-mode, D-mode, E-mode, source mode. 
calibrate  To fine-tune video levels for maximum clarity during digitizing (from videotape). 
camcorder A combination camera and recording device that records continuous pictures and generates a signal for display or recording.
Camera Control Unit (CCU) The remote control device used to set parameters for one or more television cameras.
camera log A record sheet giving details of the scenes photographed on a roll of original negative.
capstan servo The regulating device of the capstan as it passes tape through a video tape recorder.
capture The process of digitizing video or audio material, usually from a VTR, and storing it in a file on a hard disk.
capture card Sometimes called a capture or video board, the logic card installed into a computer and used to digitize video. Or, for video that is already digitized, the device that simply transfers the file to the hard disk. Using a hardware or software codec, the capture card also compresses video in and decompresses video out for display on a television monitor.
Capture Mask effect  An effect that converts the format of source data during playback. For example, it could convert video frame data between PAL (25 fps) and NTSC (29.97 fps) formats. 
capturing Refers to capturing source video for use on a computer. If analog, the captured video is converted to digital.
Cathode Ray Tube (CRT) Display device, or picture tube, for video information.
CATV Community antenna television, now generally meaning cable TV. 
CBC Canadian Broadcasting Corporation. 
CBR, (Constant Bit Rate) MPEG video compression where the amount of compression does not change.
CCIR Comite Consultatif International des Radiocommunications or International Radio Consultative Committee. The CCIR no longer exists-it has been absorbed into the parent body, the ITU. For a given "CCIR xxx" specification, see "BT.xxx". 
CCIR 601 The standard for digitizing component video. Also sometimes called D1 after the VTR format that first used this signal.
CCITT Abbreviation for Consultative Committee on International Telegraphy and Telephony; the organization that sets standards and makes recommendations for international communication.
CD Abbreviation for compact disc; the digital data storage media proposed by Philips and Sony. CD is the preferred medium for storing digital multimedia files because it is inexpensive and has a fairly large capacity (640 MB).
CD-ROM Abbreviation for compact disc read-only memory; A CD that cannot be written to.
cell animation Also called onion skinning, an animation technique in which a background painting is held in place while a series of transparent sheets of celluloid containing objects are placed over the background painting, producing the illusion of movement. One of the two main types of animation associated with digital video. Compare frame-based 2-D animation. 
cell side The base (celluloid) surface of a strip of film.
CGI Abbreviation for computer graphic imagery. 
CGMS-A Copy Generation Management System - Analog (CGMS-A). See EIA-608. 
change list  A list of instructions produced by Film Composer that is used to track and compare the differences between two versions of a digital sequence. A change list is used to update a work print cutting with specified new edits and revisions. 
change-over In projection, the act of changing from one projector to another, preferably without interrupting the continuity of projection; or, the points in the picture at which such a change is made.
channel  1. physical audio input or output. 2. One of several color components that combine to define a color image. An RGB image is made up of red, green, and blue color channels. In color correction, you can redefine color channels by blending color components in different proportions. 3. See track.
channel editor The tool used to set keyframes and modify animation curves of the channels.
channel hierarchy A set of animation parameters arranged and displayed in a logical group. A group, or upper-level, channel is called a folder. For example, the Camera folder contains channels for camera settings such as position, interest and focal length.
Chaoji VideoCD Another name for Super VideoCD. 
character generator (CG) A device or software application running on a computer and used for creating text for display over video (e.g., titles and credits).
Charge-Coupled Device, (CCD) A light sensitive semi-conductor used as an image sensor in video camera.
chassis  The housing for removable disk modules. The chassis contains a power supply, drives, and connectors for each module. 
checker-board cutting A method of assembling alternate scenes of negative in A and B rolls allowing prints to be made without visible splices.
Checksum An error-detecting scheme which is the sum of the data values transmitted. The receiver computes the sum of the received data values and compares it to the transmitted sum. If they are equal, the transmission was error-free. 
Chroma The NTSC, PAL, or SECAM video signal contains two parts that make up what you see on the display: the intensity part, and the color part. Chroma is the color part. 
Chroma Bandpass In a NTSC or PAL video signal, the luma (black and white) and the chroma (color) information are combined together. If you want to decode an NTSC or PAL video signal, the luma and chroma must be separated. A chroma bandpass filter removes the luma from the video signal, leaving the chroma relatively intact. This works reasonably well except in images where the luma and chroma information overlap, meaning that we have luma and chroma stuff at the same frequency. The filter can't tell the difference between the two and passes everything. This can make for a funny-looking picture. Next time you're watching TV and someone is wearing a herringbone jacket or a shirt with thin, closely spaced stripes, take a good look. You may see a rainbow color effect moving through that area. What's happening is that the video decoders thinks that the luma is chroma. Since the luma isn't chroma, the video decoder can't figure out what color it is and it shows up as a rainbow pattern. This problem can be overcome by using a comb filter. 
Chroma Burst See color burst. 
chroma corrector A device that corrects problems related to a video signal's chroma, color balance, and color noise.
Chroma Demodulator After the NTSC or PAL video signal makes its way through the Y/C separator, the colors must be decoded. That's what a chroma demodulator does. It takes the chroma output of the Y/C separator and recovers two color difference signals (typically I and Q or U and V). Now, with the luma information and two color difference signals, the video system can figure out what colors to display. 
chroma key A video effect wherein a particular area of color (i.e., range of chrominance) is removed from one video signal and replaced with a different signal. This effect is often used during newscasts when a weather map is inserted behind a meteorologist during a newscast.
Chroma Trap In a NTSC or PAL video signal, the luma (black and white) and the chroma (color) information are combined together. If you want to decode the video signal, the luma and chroma must be separated. The chroma trap is one method for separating the chroma from the luma, leaving the luma relatively intact. How does it work? The NTSC or PAL signal is fed to a trap filter. For all practical purposes, a trap filter allows certain frequencies to pass through, but not others. The trap filter is designed with a response to remove the chroma so that the output of the filter only contains the luma. Since this trap stops chroma, it's called a chroma trap. The sad part about all of this is that not only does the filter remove chroma, it removes luma as well if it exists within the frequencies where the trap exists. The filter only knows ranges and, depending on the image, the luma information may overlap the chroma information. The filter can't tell the difference between the luma and chroma, so it traps both when they are in the same range. What's the big deal? Well, you lose luma and this means that the picture is degraded somewhat. Using a comb filter for a Y/C separator is better than a chroma trap or chroma bandpass. 
chrominance The color portion of a video signal that is a mixture of hue and saturation, but not of luminance (brightness). Every color signal has both chrominance and luminance.
chrominance-to-burst phase The difference between the expected phase and the actual phase of the chrominance portion of the video signal relative to burst phase.
chrominance-to-luminance delay The difference in time that it takes for the chrominance portion of the video signal to pass through a system relative to the time it takes for the luminance portion. Also called relative chroma time.
chrominance-to-luminance gain The difference between the gain of the of the chrominance portion of the video signal and the gain of the luminance portion as they pass through a system.
chunking  The transfer on media files in segments so other workgroup users can access and use the media before complete files have been sent. 
CIF Common Interface Format or Common Image Format. The Common Interface Format was developed to support video conferencing. It has an active resolution of 352 x 288 and a refresh rate of 29.97 frames per second. The High-Definition Common Image Format (HD-CIF) is used for HDTV production and distribution, having an active resolution of 1920 x 1080 with a frame refresh rate of 23.976, 24, 29.97, 30, 50, 59.94, or 60 Hz. 
cinch marks Short scratches on the surface of a motion picture film, running parallel to its length; these are caused by improper winding of the roll, permitting one coil of film to slide against another.
cinching  Videotape damage due to creasing or folding. 
cinemascope Trade name of a system of anamorphic widescreen presentation.
Cinepak A commonly used QuickTime codec for compression of video files on CD-ROM. Cinipak offers temporal and spatial compression, and data-rate limiting.
cinex strip A short test print in which each frame has been printed at a different exposure level.
circle take  A take from a film shoot that has been marked for use or printing by a circled number on the camera report. 
Clamp This is basically another name for the DC-restoration circuit. It can also refer to a switch used within the DC-restoration circuit. When it means DC restoration, then it's usually used as "clamping". When it's the switch, then it's just "clamp". 
clean list (clean EDL) An edit decision list (EDL) used for linear editing that has no redundant or overlapping edits. Changes made during off-line editing often result in edits that overlap or become redundant. Most computer-based editing systems can clean an EDL automatically. Contrast with dirty list (dirty EDL). See also, on-line editing.
clip  1. A segment of source material recorded or digitized into your system at selected IN and OUT points and referenced in a project bin. The clip contains pointers to the media files in which the actual digital video and audio data is stored. 2. In a record in a log, which stands for one shot, the clip includes information about the start and end timecode for the shot, the source tape name, and the tracks selected for editing. 3. In OMFI, a general class of objects in the OMF Interchange class hierarchy representing shared properties of source clips, filler clips, attribute clips, track references, timecode clips, and edge code clips. A clip is a subclass of a component. See also master clip, media files, subclip. 
clip properties A clip's specific settings, including frame size, compressor, audio rate, etc. 
clipping The cropping of peaks (overmodulation) of the white or the black portions of a video signal.
Clipping Logic A circuit used to prevent illegal conversion. Some colors can exist in one color space but not in another. Right after the conversion from one color space to another, a color space converter might check for illegal colors. If any appear, the clipping logic is used to limit, or clip, part of the information until a legal color can be represented. Since this circuit clips off some information and is built using logic, it's not too hard to see how the name "clipping logic" was developed. 
clock timecode  See drop-frame timecode. 
Closed Captioning A service which decodes text information transmitted with the video signal and displays it on the display. For NTSC, the caption signal may be present on lines 21 and 284. For PAL, the caption signal may be present on lines 22 and 334. See the EIA-608 specification for (M) NTSC usage of closed captioning and the EIA-708 specification for DTV support. For MPEG-2 video, including ATSC and DVB, the closed caption data are multiplexed as a separate data stream within the MPEG-2 bitstream. It may use the picture layer user_data bits as specified by EIA-708, or in PES packets (private_stream_1) as specified by ETSI EN 301 775. For DVD, caption data may be 8-bit user_data in the group_of_pictures header (525/60 systems), a digitized caption signal (quantized to 16 levels) that is processed as normal video data (625/50 systems), or a subpicture that is simply decoded and mixed with the decoded video. 
Closed Subtitles See subtitles. 
Closeup, (CU)  See also ECU. 
CMYK This is a color space primarily used in color printing. CMYK is an acronym for Cyan, Magenta, Yellow, and blacK. The CMYK color space is subtractive, meaning that cyan, magenta, yellow and black pigments or inks are applied to a white surface to remove color information from the white surface to create the final color. The reason black is used is because even if a printer could print hues of cyan, magenta, and yellow inks perfectly enough to make black (which it can't for large areas), it would be too expensive since colored inks cost more than black inks. So, when black is used, instead of putting down a lot of CMY, they just use black. 
coaxial cable A single conductor, braid-shielded cable used to carry video signals. Has a 75 ohm impedance.
codec Contraction of compression/decompression algorithm; used to encode and decode, or compress and decompress data, such as sound and video files. Common codecs include those that convert analog video signals to compressed digital video files (e.g., MPEG), or that convert analog sound signals into digital sound files (e.g., RealAudio).
Coded Orthogonal Frequency Division Multiplexing Coded orthogonal frequency division multiplexing, or COFDM, transmits dig­ital data differently than 8-VSB or other single-carrier approaches. Frequency division multiplexing means that the data to be transmitted is distributed over many carriers (1,705 or 6,817 for DVB-T, as opposed to modulating a single carrier. Thus, the data rate on each COFDM carrier is much lower than that required of a single carrier. The COFDM carriers are orthogonal, or mutually perpendicular, and forward error correction ("coded") is used. COFDM is a multiplexing technique rather than a modulation technique. One of any of the common modulation methods, such as QPSK, 16-QAM or 64-QAM, is used to modulate the COFDM carriers. 
coefficient recording A form of data bit-rate reduction used by Sony in its Digital Betacam format and with its D-2 component recording accessory, the DFX-C2. Co-efficient recording uses a discrete cosine transformation and a proprietary information handling scheme to lower the data rate generated by a full bit-rate component digital signal. Such a data bit-rate reduction system allows component digital picture information to be recorded more efficiently on VTRs.
COFDM See coded orthogonal frequency division multiplexing. 
color balance Adjustment of the colour circuitry of a TV camera to the colour temperature of the light source for a given scene.
color bars An electronically-generated test signal usually consisting of six vertical strips of colour. A standard test signal that appears as a series of vertical rows of colour by which the chrominance and video levels of a camera's output or a recorded signal can be checked.
color burst The portion of the composite video signal that contains a sample of the color subcarrier. The color burst is used to establish a reference for the color information that follows it, and for decoding the color information of the signal. Burst is many cycles of 3.58 MHz pulses recorded during the horizontal blanking interval and used to establish phase relationships for determining the hue. A color television receiver's color oscillator is phase locked to the color burst.
color correction  The process of adjusting the color characteristics of video material to achieve an accurate representation of color and consistency of color from one clip in a sequence to another. The term generally refers to adjustments made across all the video in a program rather than to individual color changes made as part of a single effect. 
Color Decoder See chroma demodulator. 
Color Demodulator See chroma demodulator. 
Color Difference All of the color spaces used in color video require three components. These might be R'G'B', Y'IQ, Y'UV or Y'(R' - Y')(B' - Y'). In the Y'(R' - Y')(B' - Y') color space, the R' - Y' and B' - Y' components are often referred to as color difference signals for obvious reasons. They are made by subtracting the luma (Y') from the red and blue components. I and Q and U and V are also color difference signals since they are scaled versions of R' - Y' and B' - Y'. All the Ys in each of the Y'IQ, Y'UV and Y'(R' - Y')(B' - Y') are basically the same, although they are slightly different between SDTV and HDTV. 
Color Edging Extraneous colors that appear along the edges of objects, but don't have a color relationship to those areas. 
Color Encoder The color encoder does the exact opposite of the color decoder. It takes two color difference signals, such as I and Q or U and V, and combines them into a chroma signal. 
color frame  "A sequence of video fields required to produce a complete pattern of both field and frame synchronization and color subcarrier synchronization. The NTSC system requires four fields; PAL requires eight. "
Color Key This is essentially the same thing as chroma key. 
Color Killer A color killer is a circuit that shuts off the color decoding if the incoming video does not contain color information. How does this work? The color killer looks for the color burst and if it can't find it, it shuts off the color decoding. For example, let's say that a color TV is going to receive material recorded in black and white. Since the black and white signal does not contain a color burst, the color decoding is shut off. Why is a color killer used? Well, in the old days, the color decoder would still generate a tiny little bit of color if a black and white transmission was received, due to small errors in the color decoder, causing a black and white program to have faint color spots throughout the picture. 
Color Modulator See color encoder. 
color picker A tool used to plot colours in an image.
Color Purity This term is used to describe how close a color is to the theoretical. For example, in the Y'UV color space, color purity is specified as a percentage of saturation and +/-q, where q is an angle in degrees, and both quantities are referenced to the color of interest. The smaller the numbers, the closer the actual color is to the color that it's really supposed to be. For a studio-grade device, the saturation is +/-2% and the hue is +/-2 degrees. On a vectorscope, if you're in that range, you're studio quality. 
color reference burst  The color synchronizing signal included as part of the overall composite video signal. When compared with the color subcarrier signal, the color reference burst determines the hue of the video image. 
Color Reversal Intermediate, (CRI) A duplicate colour negative prepared by reversal processing.
Color Space A color space is a mathematical representation for a color. No matter what color space is used -- RGB, Y'IQ, Y'UV, etc. -- orange is still orange. What changes is how you represent orange. For example, the RGB color space is based on a Cartesian coordinate system and the HSI color space is based on a polar coordinate system. 
color subcarrier The 3.58 MHz (NTSC) or 4.43 MHz (PAL) signal that carries color information. The color subcarrier is superimposed onto the luminance level. Its amplitude represents saturation and its phase angle represents hue.
Color Temperature Color temperature is measured in degrees Kelvin. If a TV has a color temperature of 8,000 degrees Kelvin, that means the whites have the same shade as a piece of pure carbon heated to that temperature. Low color temperatures have a shift towards red; high color temperatures have a shift towards blue. The standard for video is 6,500 degrees Kelvin. Thus, professional TV monitors use a 6,500-degree color temperature. However, most consumer TVs have a color temperature of 8,000 degrees Kelvin or higher, resulting in a bluish cast. By adjusting the color temperature of the TV, more accurate colors are produced, at the expense of picture brightness. 
color timing The process wherein colors are referenced and alternate odd and even color fields are matched to ensure colors match from shot to shot. Most commonly found in high-end equipment, such as Betacam SP.
color wheel  A circular graph that maps hue values around the circumference and saturation values along the radius. Used in the Color Correction tool as a control for making hue offset and secondary color correction adjustments. 
ColorStream, ColorStream Pro, ColorStream HD The name Toshiba uses for the analog YPbPr video interface on their consumer equipment. If the interface supports progressive SDTV resolutions, it is called ColorStream Pro. If the interface supports HDTV resolutions, it is called ColorStream HD. 
Common Image Format See CIF. 
Common Interface Format See CIF. 
compile To compute an image or effect using a nonlinear editing, compositing, or animation program. The result is generally saved in a file on the computer. Also called render. component video
component video  The structuring of the video signal whereby color and luminance signals are kept separate from one another using the color-subtraction method Y (luminance), B–Y (blue minus luminance) and R–Y (red minus luminance), with green derived from a combination. Two other component formats are RGB and YUV. 
composite An analog video signal comprising both luminance and chrominance.
composite blanking See blanking.
composite print A motion picture print with both picture and sound on the same strip of film.
composite sound track  A sound track containing all required sound elements — usually dialog, music, and effects mixed in correct proportions. 
composite sync A signal that comprises only horizontal sync pulses, vertical sync pulses, and equalizing pulses, and has a no-signal reference level.
composite video A signal in which the luminance, chrominance, and sync information are combined into one signal using one of the coding standards (e.g., NTSC, PAL, or SECAM). The signal must take the form of composite video before it can be broadcast or recorded by standard means. Until recently, most monitors and projectors accepted only composite video signals, though many presently accept RGB signals. Contrast with component video.
compositing Layering multiple pictures on top of each other. A cutout or matte holds back the background and allows the foreground picture to appear to be in the original picture.
composition  The standard term used by OMF Interchange to refer to an edited sequence made up of a number of clips. The OMF equivalent of a sequence in an Avid system. 
compression The translation of audio or video data into a format that requires less storage space than the original data. See also, codec.
compression ratio The ratio of the amount of data in the original video compared to the amount of data in the compressed video. The higher the ratio the greater the compression.
Conditional Access This is a technology by which service providers enable subscribers to decode and view content. It consists of key decryption (using a key obtained from changing coded keys periodically sent with the content) and descrambling. The decryption may be proprietary (such as Canal+, DigiCipher, Irdeto Access, Nagravision, NDS, Viaccess, etc.) or standardized, such as the DVB common scrambling algorithm and OpenCable. Conditional access may be thought of as a simple form of digital rights management. Two common DVB conditional access (CA) techniques are SimulCrypt and MultiCrypt. With SimulCrypt, a single transport stream can contain several CA systems. This enables receivers with different CA systems to receive and correctly decode the same video and audio streams. With MultiCrypt, a receiver permits the user to manually switch between CA systems. Thus, when the viewer is presented with a CA system which is not installed in his receiver, they simply switch CA cards. 
confidence value  A measurement, expressed as a percentage, of the probability that the pattern the system finds during a motion tracking operation is identical to the pattern for which the system is searching. During a motion tracking operation, Avid Symphony calculates a confidence value for each tracking data point it creates. 
configuration file Contains a list of the device parameters, resource directory path names, and image file extensions that are required to run fire*.
conform  To prepare a complete version of your project for viewing. The version produced might be an intermediate working version or the final cut. 
conforming The process wherein an off-line edited master is used as a guide for performing final edits.
conforming a film negative  The mathematical process that the editing system uses to ensure that the edits made on a videotape version of a film project (30 fps) are frame accurate when they are made to the final film version (24 fps). 
Console  A display that lists the current system information and chronicles recently performed functions. It also contains information about particular items you are editing, such as the shots in your sequence or clips selected from bins. 
consolidate  To make copies of media files or portions of media files, and then save them on a drive. The Consolidate feature operates differently for master clips, subclips, and sequences. 
constant An option for the interpolation and/or extrapolation of an animation curve that produces a square or stepped curve.
Constant Bit Rate, (CBR) Constant bit rate (CBR) means that a bitstream (compressed or uncompressed) has the same number of bits each second. 
Contouring This is an image artifact caused by not having enough bits to represent the image. The reason the effect is called "contouring" is because the image develops vertical bands of brightness. 
contrast The range of difference between the lightest and darkest values of a picture, or maximum and minimum brightness values.
control point  A location on a Bézier curve that controls its direction. Each control point has two direction handles that can extend from it. 
control track A continuous, stable, low-frequency signal recorded onto tape. It is used to identify frame locations and control the playback of the video signal. Electronic sprocket holes recorded on video tape to guide the heads and control tape transport during playback. A signal recorded on video tape to allow the tape to play back at a precise speed in any VTR. Analogous to the sprocket holes on film.
control track editing The linear editing of videotape with equipment that reads the control track information to synchronize the editing between two decks. Contrast with timecode editing.
control-L See LANC.
convergence (1) The accuracy of the positions of the red, green, and blue beams of a color monitor or projector. (2) The adjustment of the red, green, and blue electron beams in a monitor or video projector to align the red, green and blue images.
CPU  Central processing unit. The main computational section of a computer that interprets and executes instructions. 
crash edit  An edit that is electronically unstable, such as one made using the pause control on a deck, or using a noncapstan served deck. 
crash recording  See hard recording. 
crawl Sideways movement of text across a screen.
crawling text  Text that moves horizontally over time. Examples include stock and sports score tickers that appear along the bottom of a television screen. 
Creepy Crawlies Yes, this is a real video term! Creepy-crawlies refers to a specific image artifact that is a result of the NTSC system. When the nightly news is on, and a little box containing a picture appears over the anchorperson's shoulder, or when some computer-generated text shows up on top of the video clip being shown, get up close to the TV and check it out. Along the edges of the box, or along the edges of the text, you'll notice some jaggies "rolling" up (or down) the picture. That's the creepy-crawlies. Some people refer to this as zipper because it looks like one. 
crop box A box that you superimpose over frames, either automatically or manually, to limit colour corrections, key setups etc., to the area inside the box.
cropping  The redefining of image boundaries, usually by electronically removing the top, bottom, left, or right sides of the image. 
Cross Color This occurs when the video decoder incorrectly interprets high-frequency luma information (brightness) to be chroma information (color), resulting in color being displayed where it shouldn't. 
Cross Luma This occurs when the video decoder incorrectly interprets chroma information (color) to be high-frequency luma information (brightness). 
cross mod A test method for determining the optimum print requirements for a variable area sound track.
Cross Modulation A condition when one signal erroneously modulates another signal. 
crossfade  An audio transition in which the outgoing sound gradually becomes less audible as the incoming sound becomes more distinct. Also called an audio dissolve. See also dissolve, fade. 
Crosstalk Interference from one signal that is detected on another. 
crushing the blacks  The reduction of detail in the black regions of a film or video image by compressing the lower end of the contrast range. 
cue  To shuttle a videotape to a predetermined location. 
cue channel A dedicated track for sync pulses or timecode. 
cue mark Marks used to indicate frames of interest on a clip.
curl A defect of a photographic film consisting of unflatness in a plane cutting across the width of the film. Curl may result from improper drying conditions, and the direction and amount of curl may vary with the humidity of the air to which the film is exposed.
Curves graph  An X, Y graph that plots input color values on the horizontal axis and output color values on the vertical axis. Used in the Color Correction tool as a control for changing the relationship between input and output color values. 
cut  1. An instantaneous transition from one video source to another. 2. A section of source or record tape.
cut list  A series of output lists containing specifications used to conform the film work print or negative. See also dupe list.
cutout See matte.
cutting The selection and assembly of the various scenes or sequences of a reel of film.
CVBS Abbreviation for Composite Video Baseband Signal or Composite Video, Blanking, Synchronization. 
cycles An option for the extrapolation curve that produces cycles in the curve based on the values of the first and last keyframes in the curve.
D-mode  An A-mode edit decision list (EDL) in which all effects (dissolves, wipes, graphic overlays) are performed at the end. See also A-mode, B-mode, C-mode, E-mode, source mode. 
D-to-A converter An electronic device that converts digital signals into analog signals.
D1 Digital video tape format using the CCIR 601 standard to record 4:2:2 component video on 19mm tape. A high quality of video tape format generally available. The first digital video tape format, hence D1.
D16 A format to store film resolution images on D1 format tape recorders. Records one film frame in the space normally used for 16 video frames.
D2 Digital video tape format using the 4fsc method to record composite digital video. Uses 19mm tape and a cassette similar to D1. The second digital video tape format, hence D2. 
D3 Digital video tape format using 4fsc composite signals like D2, but recorded on ½" tape. The third digital video tape format...
D4 Doesn't exist, so don't worry about it.
D5 Digital video tape format using CCIR 601, 4:2:2 video. Uses the same cassette as D3. Betcha can guess why its called D5.
D9 Digital Video tape format from JVC, before called JVC Digital-S
DAE  Digidesign Audio Engine. A trademark of Avid Technology, Inc. The application that manages the AudioSuite plug-ins. 
dailies The first positive prints made by the laboratory from the negative photographed on the previous day.
dailies  Film prints or video transfers of recently shot film material, prepared quickly so that production personnel can view and evaluate the previous day's shooting before proceeding. Also called rushes, primarily in the United Kingdom. 
DAT Abbreviation for digital audio tape; a digital audio-recording-and-playback system developed by Sony. DAT uses a small, 4mm tape and has a signal quality that can surpass that of the CD. In audio, DAT is often used for mastering a final mix of a sound track or musical composition. In computers, it is often used for archiving or backing up data and may be referred to as DDS (Digital Data Storage).
data rate The amount of data moved over a period of time, such as 10MB per second. Often used to describe a hard drive's ability to retrieve and deliver information.
DAVIC Abbreviation for Digital Audio Visual Council. It's goal was to create an industry standard for the end-to-end interoperability of broadcast and interactive digital audio-visual information, and of multimedia communication. The specification is now ISO/IEC 16500 (normative part) and ITR 16501 (informative part). 
dB Abbreviation for decibels, a standard unit for expressing relative power, voltage, or current. 
dBm Measure of power in communications. 0 dBm = 1 mW, with a logarithmic relationship as the values increase or decrease. In a 50-ohm system, 0 dBm = 0.223 volts. 
dBw Decibels referenced to 1 watt. 
DC 30 editing mode An edit mode in Premiere—specifically for DC30 users—that allows video to be streamed out of the DC30 capture card installed in a computer running Windows. 
DC Restoration DC restoration is what you have to do to a video signal after it has been AC-coupled and has to be digitized. Since the video waveform has been AC-coupled, we no longer know absolutely where it is. For example, is the bottom of the sync tip at -5v or at 1v? In fact, not only don't we know where it is, it also changes over time, since the average voltage level of the active video changes over time. Since the ADC requires a known input level and range to work properly, the video signal needs to be referenced to a known DC level. DC restoration essentially adds a known DC level to an AC-coupled signal. In decoding video, the DC level used for DC restoration is usually such that when the sync tip is digitized, it will be generate the number 0. 
DCT This is short for Discrete Cosine Transform, used in the MPEG, H.261, and H.263 video compression algorithms. 
De-emphasis Also referred to as post-emphasis and post-equalization. Deemphasis performs a frequency-response characteristic that is complementary to that introduced by pre-emphasis. 
De-emphasis Network A circuit used to restore a frequency response to its original form. 
Decibel, (DB) A unit of measure applied to both sound and electrical signals, based on a logarithmic scale. A logarithmic unit that expresses the ratio between a signal and a reference signal. For voltages, dB=20 log (V measured/V nominal). Also referred to as "db's." A logarithmic unit that expresses the ratio between a signal and a reference signal. One-tenth of a Bel, used to define the ratio of two powers, voltages, or currents, in terms of gains or losses. It is 10x the log of the power ratio and 20x the voltage or current ratio. 
Decimation When a video signal is digitized so that 100 samples are produced, but only every other one is stored or used, the signal is decimated by a factor of 2:1. The image is now 1/4 of its original size, since 3/4 of the data is missing. If only one out of five samples were used, then the image would be decimated by a factor of 5:1, and the image would be 1/25 its original size. Decimation, then, is a quick-and-easy method for image scaling. Decimation can be performed in several ways. One way is the method just described, where data is literally thrown away. Even though this technique is easy to implement and cheap, it introduces aliasing artifacts. Another method is to use a decimation filter, which reduces the aliasing artifacts, but is more costly to implement. 
deck controller  A tool that allows the user to control a deck using standard functions such as shuttle, play, fast forward, rewind, stop, and eject. 
decode To divide a composite video signal into its separate components.
decoder A device that decrypts component signals from a composite (encoded) source. Decoders are used in video displays and processing hardware where component signals are needed from a composite source.
decompose  To create new, shorter master clips based on only the material you have edited and included in your sequence. 
definition The aggregate of fine details of a video image on-screen. The higher the definition, the more discernable the details.
degauss  To demagnetize (erase) all recorded material on a magnetic videotape, an audiotape, or the screen of a color monitor. 
deinterlace Separation of field 1 and field 2 in a source clip, producing a new clip twice as long as the original.
delay edit  See overlap edit. 
Demodulation The process of recovering an original signal from a modulated carrier. 
Demodulator In NTSC and PAL video, demodulation is the technique used to recover the color difference signals. See the definitions for Chroma Demodulator and Color Decoder; these are two other names for the demodulator used in NTSC/PAL video applications. Demodulation is also used after DTV tuners to convert the transmitted DTV signal to a baseband MPEG-2 stream. 
density The negative logarithm to the base ten of the transmittance (or reflectance) of the sample. A sample which transmits 1/2 of the incident light has a transmittance of 0.50 or 50% and a density of 0.30.
depth of field The portion of an image that is in focus.
depth shadow  A shadow that extends solidly from the edges of a title or shape to make it appear three-dimensional. See also drop shadow. 
device interface A conversion device that separates the RGB and sync signals to display computer graphics on a video monitor.
differential gain Variation in the gain of the chrominance signal as the luminance signal on which it rides is varied from blanking to white level.
differential phase Variation in the phase of the chrominance subcarrier as the lumin signal on which it rides is varied from blanking to white level.
diffuse Widely spread or scattered. Used to define lighting that reflects equally in all directions producing a matte, or flat, reflection on an object. The reflection intensity depends on the light source relative to the surface of the object.
digital information in the form of binary data. Computers are digital machines that use a binary system. That is, at their most basic level, computers can distinguish between just two values, 0 and 1 (i.e, off and on). There is no simple way to represent all the values in between, such as 0.25. All data that a computer processes must be digital, encoded as a series of zeros and ones. Digital representations are approximations of analog events. They are useful because they are relatively easy to store and manipulate electronically.
Digital 8 Digital 8 compresses video using standard DV compression, but records it in a manner that allows it to use standard Hi-8 tape. The result is a DV "box" that can also play standard Hi-8 and 8 mm tapes. On playback, analog tapes are converted to a 25 Mbps compressed signal available via the i-Link digital output interface. Playback from analog tapes has limited video quality. New recordings are digital and identical in performance to DV; audio specs and other data also are the same. 
digital betacam Digital video tape format using the CCIR 601 standard to record 4:2:2 component video in compressed form on ½" tape.
Digital Component Video Digital video using three separate color components, such as Y'CbCr or R'G'B'. 
Digital Composite Video Digital video that is essentially the digitized waveform of NTSC or PAL video signals, with specific digital values assigned to the sync, blank, and white levels. 
digital cut  The output of a sequence, which is usually recorded to tape. 
Digital Disk Recorder, (DDR) A digital video recording device based on high speed computer disk drives. Commonly used as a means to get video into and out from computers.
Digital Moving Picture Exchange, (dpx) This is the SMPTE standard file format of of the Digital Moving Picture Exchange Kodak Cineon raster file format.
digital recording  A method of recording in which the recorded signal is encoded on the tape in pulses and then decoded during playback. 
Digital Rights Management Digital Rights Management (DRM) is a generic term for a number of capabilities that allow a content producer or distributor to determine under what conditions their product can be acquired, stored, viewed, copied, loaned, etc. Popular proprietary solutions include InterTrust, etc. 
Digital Signal Processing, (DSP) When applied to video cameras, DSP means that the analog signal from the CCD sensors is converted to a digital signal. It is then processed for signal separation, bandwidth settings and signal adjustments. After processing, the video signal either remains in the digital domain for recording by a digital VTR or is converted back into an analog signal for recording or transmission. DSP is also being used in other parts of the video chain, including VTRs, and switching and routing devices.
Digital Television, (DTV) Digital Television. Another acronym for the new digital television standards. See HDTV.
Digital Transmission Content Protection An encryption method (also known as "5C") developed by Sony, Hitachi, Intel, Matsushita and Toshiba for IEEE 1394 interfaces. 
Digital VCR Digital VCRs are similar to analog VCRs in that tape is still used for storage. Instead of recording an analog audio/video signal, digital VCRs record digital signals, usually using compressed audio/video. 
Digital Versatile Disc See DVD - Video and DVD - Audio. 
Digital Vertical Interval Timecode DVITC digitizes the analog VITC waveform to generate 8-bit values. This allows the VITC to be used with digital video systems. For 525-line video systems, it is defined by SMPTE 266M. BT.1366 defines how to transfer VITC and LTC as ancillary data in digital component interfaces. 
Digital Video Broadcast, (DVB) A group of international standards for the broadcasting of Digital Video regardless of medium (i.e.. satellite, terrestrial, cable, etc.).
Digital Video Disk, (DVD) Also Digital Versital Disk. A new format for putting full length movies on a 5" CD using MPEG-2 compression for "better than VHS " quality.
digital video (DV) A video signal made of binary digits. To store and manipulate analog video on a computer workstation, it must be converted to digital video.
Digital Video Effects, (DVE) Special effects, such as picture compression, rotation, reversal, etc., performed with a digital effects system. Also, the trade name for a video system manufactured by NEC.
digital workstation The computer-based system used for editing and manipulating digital audio, and synchronizing digital audio with video for video post-production applications (e.g., Adobe Premiere).
digitally record  To convert analog video and audio signals to digital signals. 
digitize To convert an analog signal into digital form for storage on disk arrays and processing.
digitizing The act of taking analog video and converting it to digital form. In 8 bit digital video there are 256 possible steps between maximum white and minimum black.
dip  "An adjustment to an audio track in which the volume gain level decreases or ""dips"" to a lower level, rather than fading completely. "
direct digital interface  The interconnection of compatible pieces of digital audio or video equipment without conversion of the signal to an analog form. 
direction handle  A line extending from a control point that controls the direction of a Bézier curve. Each control point has two direction handles. These two handles together affect how the curve passes through the control point, with one handle controlling how the curve appears before the control point, and the other handle controlling how the curve appears after the control point. 
directory A logical or physical portion of a hard disk drive where the operating system stores files.
DirectShow The application programming interface (API) for client-side playback, transformation, and capture of a wide variety of data formats. DirectShow is the successor to Microsoft Video for Windows and Microsoft ActiveMovie, significantly improving on these older technologies.
dirty list (dirty EDL) An edit decision list (EDL) containing overlapping or redundant edits. Contrast with clean list (clean EDL).
disc array Multiple hard disks formatted to work together as if they were part of a single hard drive. Disc arrays are typically used for high data rate video storage.
Discrete Cosine Transform, (DCT) A widely used method of video compression. Also an Ampex CCIR 601 digital VTR using DCT to compress the video before recording it to tape.
Discrete Time Oscillator (DTO) A discrete time oscillator is a digital version of the voltage-controlled oscillator. 
disk  The medium used to store data in computer-readable form. 
displacement mapping The adding of a 3D effect to a 2D image.
dissolve  A video or audio transition in which an image from one source gradually becomes less distinct as an image from a second source replaces it. An audio dissolve is also called a segue. See also crossfade, fade. 
distortion An undesirable effect that can occur in audio and video signals. In audio, distortion may manifest itself as discordant or harsh sound, or as static. In video, distortion may appear as waves, snow, or incorrect colors.
distribution amplifier (DA) See video amplifier.
dither pattern The matrix of color or gray-scale values used to represent colors gray shades in a display system with a limited color palette.
dithering Alternating the colors of adjacent pixels to approximate intermediate colors. For example, adjacent blue and yellow pixels appear from a distance to be green. Dithering enables monitors to approximate colors they are unable to display.
DLT A high capacity data tape format.
Dolby Refers to both Dolby Laboratories and to noise reduction systems they produce.
Dolby Digital An audio compression technique developed by Dolby. It is a multi-channel surround sound format used in DVD and HDTV. 
Dolby Laboratories Founded in 1965, Dolby Laboratories is well known for the technologies it has developed for improving audio sound reproduction, including their noise reduction systems (e.g., Dolby A, B, and C), Dolby Digital (AC-3), Dolby Surround, and more. For more information, visit the Dolby Laboratories Web site.
dongle  A hardware device used as a key to control the use of licensed software. The software can be installed on any system but will run only on the system that has a dongle installed. The dongle connects to the Apple Desktop Bus on Macintosh systems or to the parallel (printer) port on PC systems. 
dot pitch On a color screen, the measured distance in millimeters between a dot of a specific color — either red, green or blue — and the closest dot of the same color. The smaller the dot pitch, the more detailed and sharper the image. Dot pitch also determines the resolution of a screen (e.g., a computer monitor).
Double Buffering As the name implies, you are using two buffers -- for video, this means two frame buffers. While buffer 1 is being read, buffer 2 is being written to. When finished, buffer 2 is read out while buffer 1 is being written to. 
double system  Any film system in which picture and sound are recorded on separate media. A double system requires the resyncing of picture and sound during postproduction. 
double-perf film  Film stock with perforations along both edges of the film. 
double-strand editing  See A/B-roll. 
Downconverter A circuit used to change a high-frequency signal to a lower frequency. 
Downlink The frequency satellites use to transmit data to Earth stations. 
DRM See Digital Rights Management. 
Drop Field Scrambling This method is identical to the sync suppression technique for scrambling analog TV channels, except there is no suppression of the horizontal blanking intervals. Sync pulse suppression only takes place during the vertical blanking interval. The descrambling pulses still go out for the horizontal blanking intervals (to fool unauthorized descrambling devices). If a descrambling device is triggering on descrambling pulses only, and does not know that the scrambler is using the drop field scrambling technique, it will try to reinsert the horizontal intervals (which were never suppressed). This is known as double reinsertion, which causes compression of the active video signal. An unauthorized descrambling device creates a washed-out picture and loss of neutral sync during drop field scrambling. 
drop shadow  A shadow that is offset from a title or shape to give the feeling of spatial dimension. See also depth shadow. 
drop-frame The timecode adjustment made to handle the 29.97 per second frame rate of color video by dropping certain, agreed-upon frames to compensate for the 0.03 fps discrepancy. Drop-frame timecode is critical in broadcast applications. Contrast with non-drop-frame.
drop-frame timecode  "A type of SMPTE timecode designed to match clock time exactly. Two frames of code are dropped every minute on the minute except the tenth minute, to correct for the fact that color frames occur at a rate of 29.97 fps, rather than an exact 30 fps. Drop-frame timecode is recorded with semicolons between the digits; for example, 1;00;10;02. Compare with non-drop-frame timecode. "
drop-out The area of a magnetic tape where information is missing. Drop-out may occur due to dust, lack of oxide, or other causes.
drop-out compensator Technology that replaces dropped video with the video from the previous image's scan line. High-end time base correctors usually included a dropout compensator.
dropped frames Missing frames lost during the process of digitizing or capturing video. Dropped frames can be caused by a hard drive incapable of the necessary data transfer rate.
DTCP Short for digital transmission content protection. 
DTS DTS stands for Digital Theater Systems. It is a multi-channel surround sound format, similar to Dolby Digital. For DVDs that use DTS audio, the DVD - Video specification still requires that PCM or Dolby Digital audio still be present. In this situation, only two channels of Dolby Digital audio may be present (due to bandwidth limitations). 
DTV  Digital television. The technology enabling the terrestrial transmission of television programs as data. See also HDTV. 
dub To record or mix pre-recorded audio or video from one or more sources to a another source to create a single recording. See also, bump-up.
dubbing  1. In videotape production, the process of copying video or audio from one tape to another. 2. In film production, the process of replacing dialog on a sound track. See also ADR, foley. 
dubmaster  A second-generation copy of a program master used for making additional preview or distribution copies, thereby protecting the master from overuse. 
dupe  Duplicate. A section of film or video source footage that has been repeated (duplicated) one or more times in an edited program. 
dupe list  A sublist of duplicated clips of film requiring additional prints or copies of negative for film finishing. See also cut list. 
dupe reel  A reel designated for the recording and playback of dupes (duplicate shots) during videotape editing. 
duration  The length of time (in hours, minutes, and seconds or in feet and frames) that a particular effect or section of audio or video material lasts. 
DV Abbreviation for digital video. DV can also denote the type of compression used by DV systems or a format that incorporates DV compression. The DV designation is also used to for a special type of tape cartridge used in DV camcorders and DV tape decks.
dv_export An export mode in Adobe Premiere that enables digital video to be exported through a capture card. 
DV25 The most common form of DV compression. DV25 uses a fixed data rate of 25 megabits per second.
DVD Abbreviation for digital versatile disc. DVDs look like CDs, but have a much larger storage capacity—more than enough for a feature-length film compressed with MPEG-2. DVDs require special hardware for playback. 
DVD-Audio DVDs that contain linear PCM audio data in any combination of 44.1, 48.0, 88.2, 96.0, 176.4, or 192 kHz sample rates, 16, 20, or 24 bits per sample, and 1 to 6 channels, subject to a maximum bit rate of 9.6 Mbps. With a 176.4 or 192 kHz sample rate, only two channels are allowed. Meridian Lossless Packing (MLP) is a lossless compression method that has an approximate 2:1 compression ratio. The use of MLP is optional, but the decoding capability is mandatory on all DVD-Audio players. Dolby Digital compressed audio is required for any video portion of a DVD-Audio disc. 
DVD-Interactive DVD-Interactive is under development (due summer 2002), and is intended to provide additional capability for users to do interactive operation with content on DVDs or at Web sites on the Internet. It will probably be based on one of three technologies: MPEG-4, Java/HTML, or software from InterActual. 
DVD-ROM DVD disks for computers. Expected to eventually replace the conventional CD-ROM. The initial version stores 4.7GB on one disk. DVD-ROM drives for computers will play DVD movie disks.
DVD-Video DVDs that contain about two hours of digital audio, video, and data. The video is compressed and stored using MPEG-2 MP@ML. A variable bit rate is used, with an average of about 4 Mbps (video only), and a peak of 10 Mbps (audio and video). The audio is either linear PCM or Dolby Digital compressed audio. DTS compressed audio may also be used as an option. Linear PCM audio can be sampled at 48 or 96 kHz, 16, 20, or 24 bits per sample, and 1 to 8 channels. The maximum bitrate is 6.144 Mbps, which limits sample rates and bit sizes in some cases. 
DVE  Digital video effect. 
DVE move Making a picture shrink, expand, tumble, or move across the screen. 
DVE wipe A wipe effect in which the incoming clip appears in the form of a DVE similar to those you create with the DVE tool.
DVI, DVI-D, DVI-I, DVI-CE Abbreviation for Digital Visual Interface. This is a digital RGB video interface to a display. The EIA-861 standard specifies how to include data such as aspect ratio and format information. The VESA EEDID and DI-EXT standards document data structures and mechanisms to communicate data across DVI. Download the DVI specification. DVI-D is a digital-only interface. DVI-I handles both analog and digital. DVI-CE (now known as HDMI) is a proposed modified version of DVI that is targeted for consumer equipment. It includes audio capability and uses a smaller connector. 
DVITC See digital vertical interval timecode. 
DVR See digital video recorder. 
dynamic range  An audio term that refers to the range between the softest and loudest levels a source can produce without distortion.
dynamic tracking A video head's ability to find and follow an adjacent track by bending back and forth. Dynamic tracking offers true freeze-frame instead of freeze-field, variable-speed playback, and playing in reverse. 
E-mode  A C-mode edit decision list (EDL) in which all effects (dissolves, wipes, and graphic overlays) are performed at the end. See also A-mode, B-mode, C-mode, D-mode, source mode. 
EBU  European Broadcasting Union. A standards-setting organization in which only users (not vendors) have a voice. See also AES/EBU. 
EBU timecode The timecode system created by the EBU and based on SECAM or PAL video signals.
ECU  Extreme closeup. 
edge filter  A filter that applies anti-aliasing to graphics created in the Title tool. 
edge numbers Numbers printed on the edge of 16 and 35mm motion picture film every foot which allows frames to be easily identified in an edit list. 
edgecode  See edge numbers, key numbers. 
edit  To assemble film or video, audio, effects, titles, and graphics to create a sequence. 
edit control The connection on a camcorder or a VCR for communicating with an edit-control device. See also, LANC.
edit controller  An electronic device, often computer-based, that allows an editor to precisely control, play, and record to various videotape machines. 
Edit Decision List, (EDL) List of edits prepared during off-line editing prior to on-line editing. A list of edit decisions made during an edit session and usually saved to floppy disk. Allows an edit to be redone or modified at a later time without having to start all over again. An EDL uses SMPTE timecode to interchange information between offline and online editing systems. A file containing a list of edit decision statements used to create a video production.
edit master Teh first generation (original) of a final edited tape.
edit point The location on a video tape at which a production edit (e.g., an effect) occurs.
edit rate  In compositions, a measure of the number of editable units per second in a piece of media data (for example, 30 fps for NTSC, 25 fps for PAL, and 24 fps for film). 
edit sequence An assembly of clips.
EDL  Edit decision list. A list of edits made during offline editing and used to direct the online editing of the master. See also cut list. 
effects  "The manipulation of an audio or video signal. Types of film or video effects include special effects (F/X) such as morphing; simple effects such as dissolves, fades, superimpositions, and wipes; complex effects such as keys and DVEs; motion effects such as freeze frame and slow motion; and title and character generation. Effects usually have to be rendered because most systems cannot accommodate multiple video streams in real time. See also rendering. "
EIA  "Electronic Industries Association. The largest trade organization that covers the television and audio fields. EIA publishes a catalog of standards; the most important standards to the television and audio industries are the ones developed by its Parts Division and its Consumer Electronics Group. "
EIA-516 United States teletext standard, also called NABTS. Purchase the specification. 
EIA-608 United States closed captioning and extended data services (XDS) standard. Revision B adds Copy Generation Management System - Analog (CGMS-A), content advisory (v-chip), Internet Uniform Resource Locators (URLs) using Text-2 (T-2) service, 16-bit Transmission Signal Identifier, and transmission of DTV PSIP data. Purchase the specification. 
EIA-708 United States DTV closed captioning standard. EIA CEB-8 also provides guidance on the use and processing of EIA-608 data streams embedded within the ATSC MPEG-2 video elementary transport stream, and augments EIA-708. Purchase the specifications. 
EIA-744 NTSC "v-chip" operation. This standard added content advisory filtering capabilities to NTSC video by extending the EIA-608 standard. It is now included in the latest EIA-608 standard, and has been withdrawn. 
EIA-761 Specifies how to convert QAM to 8-VSB, with support for OSD (on screen displays). Purchase the specification. 
EIA-762 Specifies how to convert QAM to 8-VSB, with no support for OSD (on screen displays). Purchase the specification. 
EIA-766 United States HDTV content advisory standard. Purchase the specification. 
EIA-770 This specification consists of three parts (EIA-770.1, EIA-770.2, and EIA-770.3). EIA-770.1 and EIA-770.2 define the analog YPbPr video interface for 525-line interlaced and progressive SDTV systems. EIA-770.3 defines the analog YPbPr video interface for interlaced and progressive HDTV systems. EIA-805 defines how transfer VBI data over these YPbPr video interfaces. Purchase the specification. 
EIA-775 EIA-775 defines a specification for a baseband digital interface to a DTV using IEEE 1394 and provides a level of functionality that is similar to the analog system. It is designed to enable interoperability between a DTV and various types of consumer digital audio/video sources, including settop boxes and DVRs or VCRs. EIA-775.1 adds mechanisms to allow a source of MPEG service to utilize the MPEG decoding and display capabilities in a DTV. EIA-775.2 adds information on how a digital storage device, such as a D-VHS or hard disk digital recorder, may be used by the DTV or by another source device such as a cable set-top box to record or time-shift digital television signals. This standard supports the use of such storage devices by defining Service Selection Information (SSI), methods for managing discontinuities that occur during recording and playback, and rules for management of partial transport streams. EIA-849 specifies profiles for various applications of the EIA-775 standard, including digital streams compliant with ATSC terrestrial broadcast, direct-broadcast satellite (DBS), OpenCable™, and standard definition Digital Video (DV) camcorders. Purchase the specification. 
EIA-805 This standard specifies how VBI data are carried on component video interfaces, as described in EIA-770.1 (for 480p signals only), EIA-770.2 (for 480p signals only) and EIA-770.3. This standard does not apply to signals which originate in 480i, as defined in EIA-770.1 and EIA-770.2. The first VBI service defined is Copy Generation Management System (CGMS) information, including signal format and data structure when carried by the VBI of standard definition progressive and high definition YPbPr type component video signals. It is also intended to be usable when the YPbPr signal is converted into other component video interfaces including RGB and VGA. Purchase the specification. 
EIA-861 The EIA-861 standard specifies how to include data, such as aspect ratio and format information, on DVI and HDMI. Purchase the specification. 
EIA-J CPR-1204 This EIA-J recommendation specifies another widescreen signaling (WSS) standard for NTSC video signals. WSS may be present on 20 and 283. Purchase the specification. 
EIA/IS-702 NTSC Copy Generation Management System - Analog (CGMS-A). This standard added copy protection capabilities to NTSC video by extending the EIA-608 standard to control the Macrovision anti-copy process. It is now included in the latest EIA-608 standard, and has been withdrawn. 
EISA slot Connection slot to a type of computer expansion bus found in some computers. EISA is an extended version of the standard ISA slot design.
Electronic Beam Recorder, (EBR) Exposes film directly using an electronic beam compared to recording from a CRT. 
electronic editing  The assembly of a finished video program in which scenes are joined without physically splicing the tape. Electronic editing requires at least two decks: one for playback and the other for recording. 
Electronic Pin Register, (EPR) Stabilizes the film transport of a telecine. Reduces ride (vertical moment) and weave (horizontal movement). Operates in read time.
encode To merge the individual digital or analog video signals (e.g., red, green, and blue) into a combined signal. 
encoder A circuit that combines the primary red, green and blue signals into a composite video signal. NTSC, PAL and SECAM have different encoding systems.
encoding  1. he addition of technical data such as timecode, cues, or closed-captioned information to a video recording. 2. The conversion of RGB S-Video to composite video.
energy plot  The display of audio waveforms as a graph of the relative loudness of an audio signal. 
Enhanced Definition Television, (EDTV) EDTV is a television capable of displaying at least 480 progressive active scan lines. No aspect ratio is specified. For the ATSC system, typical EDTV (luminance) resolutions and refresh rates are: 
equalization  The balancing of various frequencies to create a pleasing sound by attenuating or boosting specific frequencies within the sound. 
Equalization Pulses These are two groups of pulses, one that occurs before the serrated vertical sync and another group that occurs after. These pulses happen at twice the normal horizontal scan rate. They exist to ensure correct 2:1 interlacing in early televisions. 
Error Concealment The ability to hide transmission errors that corrupt the content beyond the ability of the receiver to properly display it. Techniques for video include replacing the corrupt region with either earlier video data, interpolated video data from previous and next frames, or interpolated data from neighboring areas within the current frame. Decoded MPEG video may also be processed using deblocking filters to reduce blocking artifacts. Techniques for audio include replacing the corrupt region with interpolated audio data. 
Error Resilience The ability to handle transmission errors without corrupting the content beyond the ability of the receiver to properly display it. MPEG-4 supports error resilience through the use of resynchronization markers, extended header code, data partitioning, and reversible VLCs. 
ethernet A form of local area network (LAN) used to interconnect computers and peripheral devices. Ethernet is a standardized system; many manufacturers supply hardware and software of ethernet networks.
ETSI EN 300 163 This specification defines NICAM 728 digital audio for PAL. Download the specification. 
ETSI EN 300 294 Defines the widescreen signaling (WSS) information for PAL video signals. For (B, D, G, H, I) PAL systems, WSS may be present on line 23. Download the specification. 
ETSI EN 300 421 This is the DVB-S specification. Download the specification. 
ETSI EN 300 429 This is the DVB-C specification. Download the specification. 
ETSI EN 300 744 This is the DVB-T specification. Download the specification. 
ETSI EN 301 775 This is the specification for the carriage of Vertical Blanking Information (VBI) data in DVB bitstreams. Download the specification. 
ETSI ETR 154 This specification defines the basic MPEG audio and video parameters for DVB applications. Download the specification. 
ETSI ETS 300 231 This specification defines information sent during the vertical blanking interval using PAL teletext (ETSI ETS 300 706) to control VCRs in Europe (PDC). Download the specification. 
ETSI ETS 300 706 This is the enhanced PAL teletext specification. Download the specification. 
ETSI ETS 300 707 This specification covers Electronic Program Guides (EPG) sent using PAL teletext (ETSI ETS 300 706). Download the specification. 
ETSI ETS 300 708 This specification defines data transmission using PAL teletext (ETSI ETS 300 706). Download the specification. 
ETSI ETS 300 731 Defines the PALplus standard, allowing the transmission of 16:9 programs over normal PAL transmission systems. Download the specification. 
ETSI ETS 300 732 Defines the ghost cancellation reference (GCR) signal for PAL. Download the specification. 
ETSI ETS 300 743 This is the DVBsubtitling specification. Download the specification. 
event  A number assigned by the editing system to each performed edit. In most computer editing systems, an event defines an action or a sequence of actions performed by the computer in a single pass of the record tape. 
exabyte An 8mm data tape format. Popular for storing graphics files due to it's low cost and high capacity (commonly 8GB, but new models hold up to 40GB). Exabyte is also the number of bytes that comes after Petabyte. Too big a number to think about.
expansion slot Electrical connection slot mounted on a computer's motherboard (main circuit board). It allows several peripheral devices to be connected inside a computer.
extract  To remove a selected area from an edited sequence and close the resulting gap in the sequence. 
extrapolation A mode that defines the shape of an animation curve before the first and after the last control points on the curve. Extrapolation affects the animation before the first keyframe and after the last keyframe. Extrapolation is only apparent if there are frames before and after the keyframes. 
eyedropper  A tool for taking a color from a screen image and using that color for text or graphics.
Fade Fading is a method of switching from one video source to another. Next time you watch a TV program (or a movie), pay extra attention when the scene is about to end and go on to another. The scene fades to black, then a fade from black to another scene occurs. Fading between scenes without going to black is called a dissolve. One way to do a fade is to use an alpha mixer. 
fade to black A transition commonly used to signify the end of a scene, in which an image or sound smoothly fades to a black scren or silence (also called a fade-out transition). Similarly, you could start a new scene with a fade up from black (or fade-in) transition.
FAT  File Allocation Table. A file system used on MS-DOS and Windows computers. 
FCC Abbreviation for the Federal Communications Commission; the bureau that regulates radio and television broadcast standards United States. 
feedback  A loud squeal or howl caused when the sound from a loudspeaker is picked up by a nearby microphone and reamplified. Also caused when the output of a tape recorder is fed back into the record circuit. 
Field An interlaced display is made using two fields, each one containing half of the scan lines needed to make up one frame of video. Each field is displayed in its entirety -- therefore, the odd field is displayed, then the even, then the odd, and so on. Fields only exist for interlaced scanning systems. So for (M) NTSC, which has 525 lines per frame, a field has 262.5 lines, and two fields make up a 525-line frame. 
field dominance Setting in the menu that determines whether field 1 or 2 of a clip is dominant. Commands that render to fields use the specified field dominance. 
file system  A way of organizing directories and files on a disk drive, such as FAT or NTFS for Windows computers. See also format. 
fill Solid colour or a reference mage that you use to fill areas of an image. 
filled key A key effect in which the key source image is different from the foreground image. Areas not keyed (that is, not made transparent) in the key source image are filled with the corresponding areas of the foreground image. filter
filler clip  A segment of a sequence that contains no audio or video information. Filler can be added to the Source monitor (or pop-up monitor) and edited into a sequence. See also filler proxy. 
filler proxy  The result of a composition specifying media to be played for the filler clips in each track. 
film timecode  Timecode added to the film negative during the film shoot via a film timecode generator. Film timecode numbers are synced to the film key numbers on the dailies during the telecine transfer process. A special key link reader is required for viewing the film timecode. 
FireWire The Apple Computer trade name for IEEE 1394. 
fit to fill An insert edit where an incoming source clip replaces an existing segment (or gap) in the record clip. A fit to fill edit functions like a swap shot edit except that the edit sequence does not ripple. If the source clip has a different length than the segment it replaces, the source clip is shortened or lengthened proportionally to fit the duration of the replaced segment.
flash frame  After a long, complex piece is edited, small bits of video might be accidentally left in a sequence. When the Timeline is zoomed to 100 percent, these small, unwanted, pieces might not be visible. An editor can find these bits using the Find Flash Frame command. 
Flicker Flicker occurs when the frame rate of the video is too low. It's the same effect produced by an old fluorescent light fixture. The two problems with flicker are that it's distracting and tiring to the eyes. 
FM See frequency modulation. 
foley Background sounds added during audio sweetening to heighten realism, e.g. footsteps, bird calls, heavy breathing, short gasps, etc. 
footage encoder time code generator An electronic device which takes the input from a reader of keykode numbers, decodes this information and correlates the numbers with the SMPTE time code it generates. These data, along with 3:2 pull-down status of the transfer, footage count, and audio time code (if applicable) are made available for window burn-ins, VITC-LTC recording and output to a computer. (See KODAK Guide to Film and Video Post Production - Publications H-64.)
format  To prepare a disk drive or floppy disk for use. For Windows computers, you format a disk drive by copying a file system (either FAT or NTFS) to the drive. 
formatting  The transfer and editing of material to form a complete program, including any of the following: countdown, test patterns, bars and tone, titles, credits, logos, space for commercial, and so forth. 
fps  "Frames per second. A measure of the film or video display rates (NTSC = 30 fps; PAL = 25 fps; SECAM = 25 fps; Film = 24 fps). "
Frame A frame of video is essentially one picture or "still" out of a video stream. By playing these individual frames fast enough, it looks like people are "moving" on the screen. It's the same principle as flip cards, cartoons, and movies. 
frame  One complete video picture. A frame contains two video fields, scanned at the NTSC rate of approximately 30 fps or the PAL rate of 25 fps. 
frame accurate The importance of specific edits as compared to the ability to start, stop, and search for specific frames of video. Frame-accurate editing requires the use of a timecode system. 
frame buffer A segment of RAM used for storing a digitally captured image. A frame buffer can be either high or low resolution. This term is often used incorrectly to refer to video-capture cards, though such cards often include frame buffers. 
frame grabber A device that enables the real-time capture of a single frame of video. The frame is captured within a temporary buffer for manipulation or conversion to specified file format. The buffers of some frame grabbers are large enough to store several complete frames, enabling the rapid capture of many images. A frame grabber differs from a digitizer in that a digitizer captures complete sequential frames, so it must use compression or acceleration or both to capture in real-time. 
frame offset  A way of indicating a particular frame within the group of frames identified by the edge number on a piece of film. For example, a frame offset of +12 indicates the twelfth frame from the frame marked by the edgecode. 
frame pulse  A pulse superimposed on the control track signal. Frame pulses are used to identify video track locations containing vertical sync pulses. 
frame rate The number of frames per second displayed during playback. 
Frame Rate Conversion Frame rate conversion is the act of converting one frame rate to another. 
frame store synchronizer A full-frame synchronizer used by a time-base corrector with full-frame memory and can be used to synchronize two video sources. 
frame synchronizer  A device that allows a nonsynchronous video source, such as a satellite or microwave feed, to be used in a timed-video environment by capturing entire frames. 
frame-based 2-D animation A two-dimensional animation technique in which an object is moved from one position, size, and color to another. Adobe After Effects, for example, uses keyframes to create frame-based 2-D animation. One of the two main types of animation associated with digital video. Compare cell animation. 
framestore A digital device designed to store and display a single television frame as a "freeze frame". Hard disk space used to store and retrieve images. Framestores can be disk arrays, a single disk, or a single file in a file system. 
freeze frame  A video effect that appears to stop the action. Freeze frames can be created during recording, digitizing, or during an editing session. Compositions can create this effect using a track repeat object, which can specify the display of a single frame for a period of time. 
frequency The rate of occurrence of events in a system. The frequency of electrical signals is measured in Hertz, or cycles per second.
Frequency Modulation, (FM) This technique sends data as frequency variations of a carrier signal. 
frequency response A system's gain characteristic versus frequency. Frequency response is often stated as a range of single frequencies over which gain varies by less than a specified amount.
Front Porch This is the area of the video waveform that sits between the start of horizontal blanking and the start of horizontal sync. 
gain  1. A measurement of the amount of white in a video picture.2. Audio levels or loudness. See also waveform, white point. 
gamma A term that describes the tonal reproduction characteristics of a video signal. A parameter that adjusts the midlevel gray values in an image. A process to correct brightness and internal microcontrast within a computer image.
Gamma Correction Before being displayed, linear RGB data must be processed (gamma corrected) to compensate for the nonlinearity of the display. 
gamut The range of voltages allowed for a video signal, or for a video signal component. Signal voltages outside the allowable range (i.e., those that exceed the gamut) may cause distortions such as clipping.
gang  Any combination of multiple tracks that are grouped. An edit that is performed on one track is also performed on tracks that are ganged together. 
GCR See ghost cancellation reference signal. 
generation  The number of times material has been rerecorded. The original videotaped material is the first generation. A copy of the original is a second-generation tape, and so on. Each generation shows a gradual loss of image quality. With digital copies, there is little or no loss in quality. 
generation loss The incremental reduction in image or sound quality or both due to repeated copying of analog video or audio information and noise introduced during transmission. Generation loss does not occur when copying digital video unless it is repeatedly compressed and decompressed.
generations The number of times a video clip is copied or processed.
genlock A system whereby the internal sync generator in a device, such as a camera, locks on to and synchronizes itself with an incoming signal. The process of synchronizing the timing between different video signals by generating a new video signal that is time-locked to the sync of the original signals. Genlock devices enable computer text and graphics to be superimposed onto video.
Ghost Cancellation Reference A reference signal on (M) NTSC scan lines 19 and 282 and (B, D, G, H, I) PAL scan line 318 that allows the removal of ghosting from TVs. Filtering is employed to process the transmitted GCR signal and determine how to filter the entire video signal to remove the ghosting. ITU-R BT.1124 and ETSI ETS 300 732 define the standard each country uses. ATSC A/49 also defines the standard for NTSC. 
gigabyte (GB)  Approximately one billion bytes (1,073,741,824 bytes) of information. 
GPI  General-purpose interface. In computerized editing systems, GPIs allow the computer to control various remote components. 
GPI trigger General Purpose Interface. The signal sent by a GPI that instructs an external device to execute a particular command, such as to start or stop playback of a video effect.
gradient A blended mix of two or three colours that you can use to draw or fill objects.
graphics overlay Text or a graphics image that's superimposed on video.
graticule The calibrated scale for quantifying information on a waveform monitor or vectorscope screen. The graticule can be silk-screened onto the CRT face plate (internal graticule), silk -screened onto a piece of plastic or glass that fits in from of the CRT (external graticule), or it can be electronically generated as part of the display.
gray point  See gamma. 
Grayscale The term gray scale has several meanings. It some cases, it means the luma component of color video signals. In other cases, it means a black-and-white video signal. 
green screen See blue screen. 
Group of Pictures (GOP) The group of I, B and P frames required to make a complete MPEG sequence. A typical MPEG GOP could be IBBPBBPBBP.
GUI  "Graphical user interface. The graphic image on the screen containing representations of buttons, sliders, and dials; used to control the editing process."
H.261, H.263  The ITU-T H.261 and H.263 video compression standards were developed to implement video conferencing over ISDN, LANs, regular phone lines, etc. H.261 supports video resolutions of 352 x 288 and 176 x 144 at up to 29.97 frames per second. H.263 supports video resolutions of 1408 x 1152, 704 x 576, 352 x 288, 176 x 144, and 128 x 96 at up to 29.97 frames per second. Purchase the H.261 or H.263 specification. 
H.26L A next-generation video codec, H.26L has been a university research project until recently. It is now being worked on by MPEG, with the intention of making it part 10 of the MPEG-4 standard. 
H phase  Horizontal phase. The horizontal blanking interval used to synchronize the timing of two or more video signals. 
handles  Material outside the IN and OUT points of a clip in a sequence. The Avid system creates handles when you decompose or consolidate material. The Decompose and Consolidate features can create new master clips that are shorter versions of the original master clip. The handles are used for dissolves and trims with the new, shorter master clips. 
hard commit Removing the soft edit properties of an edit sequence. Hard commits are different from soft commits in that hard commits cannot be restored--the commit is permanent. Hard commits force a render on the selected elements.
hard disk  A magnetic data recording disk that is permanently mounted within a disk drive. 
hard key A key effect in which areas of teh keyed image are either completely transparent or completely opaque, creating a hard edge between the keyed image and background image.
hard recording  The immediate recording of all audio, video, timecode, and control tracks on a magnetic recorder. Because hard recording creates breaks in any existing timecode or control track on the tape, this procedure is often performed on blank tape when an edit is not required or in emergency circumstances. See also crash recording. 
hardware inventory An IRIX command (hinv) that you use to list the hardware, memory, and peripheral equipment in , or connected to, your workstation.
HD-CIF See CIF. 
HD-SDTI High Data-Rate Serial Data Transport Interface, defined by SMPTE 348M. 
HDMI Abbreviation for High Definition Multimedia Interface. This is a proposed digital audio/video interface for consumer equipment. It is designed to replace DVI in a backwards compatible fashion and supports EIA-861 and HDCP. Digital RGB or YCbCr data at rates up to 5 Gbps are supported (HDTV requires 2.2 Gbps). Up to 8 channels of 32-192 kHz digital audio are also supported, along with AV.link (remote control) capability and a smaller connector. 
HDTV, (High Definition Television) Abbreviation for High-Definition Television. The FCC is close to establishing a broadcast standard for HDTV. The SMPTE has proposed a high-definition television production standard consisting of 1125 lines, 2:1 interlace, 60 Hz field (30 fps), a 16:9 aspect ratio and 30 MHz RGB and luminance bandwidth. High-end video applications can handle the 16:9 pixel aspect ratio. 
A TV format capable of displaying on a wider screen (16x9 as opposed to the conventional 4x3) and at higher resolution. Rather than a single HDTV standard the FCC has approved several different standards, allowing broadcasters to choose which to use. This means new TV sets will have to support all of them. All of the systems will be broadcast as component digital. 
head Video or audio material that has been trimmed out of the front (leading) end of a clip.
head frame  The first frame in a clip of film or a segment of video. 
headroom  1. In video, the room that should be left between the top of a person's head and the top of the frame when composing a clip. 2. In audio, the amount of available gain boost remaining before distortion is encountered
heads out  Film or tape wound on a reel with the tail on the inside next to the hub and the head end on the outside. 
helical recording A video recording method in which the information is recorded in diagonal tracks. Also known as slant-track recording. 
hermite An option for the interpolation of an animation curve that produces a smooth curve by assigning a slope to each control point on the curve. Each control point has a tangent handle that you can use to adjust the slope for the point. 
hertz (Hz)  The SI unit of frequency equal to one cycle per second. See also kilohertz (kHz), megahertz (MHz). 
Hi Con  A high-contrast image used for creating matte keys. 
HI-FI Abbreviation for high fidelity, referring to high-quality audio tracks recorded by many VCRs. These audio quality of these tracks approaches that of a CD.
hierarchy A structure of levels that organizes component elements. For example, the IRIX operating system uses a tree-like hierarchy to organize directories on a hard disk drive. 
highlights Light areas in an image. 
Highpass Filter A circuit that passes frequencies above a specific frequency (the cutoff frequency). Frequencies below the cutoff frequency are reduced in amplitude to eliminate them. 
HIIP  Host Image Independence Protocol. A registered trademark of Avid Technology, Inc. HIIP allows the Avid system to import and export files in various standard formats. Also called Image Independence. 
HIIP folder  The folder containing files that support the Host Image Independence Protocol. 
histogram A bar graph you use in the Keyer to adjust the values of the red, green, blue and luminance channels of an image when you create a matte.
HLS, (hue, lightness, saturation) A colour model based on human perception of colours.
Horizontal Blanking During the horizontal blanking interval, the video signal is at the blank level so as not to display the electron beam when it sweeps back from the right to the left side of the CRT screen. 
horizontal blanking interval The time interval between the display of the right-most pixel on one line and the left-most pixel on the next.
horizontal drive See horizontal sync.
horizontal resolution The smallest increment of a television picture that can be discerned in the horizontal plane. This increment is measured in frequency or lines and depends on the video bandwidth. 
horizontal scan frequency The frequency at which horizontal sync pulses start the horizontal retrace for each line. A high frequency is needed for a non-interlaced scan. The horizontal sync frequency for NTSC is 15.75 KHz.
Horizontal Scan Rate This is how fast the scanning beam in a display sweeps from side to side. In the NTSC system, this rate is 63.556 ms, or 15.734 kHz. That means the scanning beam moves from side to side 15,734 times a second. 
Horizontal Sync This is the portion of the video signal that tells the display where to place the image in the left-to-right dimension. The horizontal sync pulse tells the receiving system where the beginning of the new scan line is. 
host bus Computer system bus to which a card is connected by insertion in the appropriate slot. This will be either a PCI, and EISA or an ISA bus.
House Sync This is another name for black burst. 
HSI HSI stands for Hue, Saturation and Intensity. HSI is based on polar coordinates, while the RGB color space is based on a three-dimensional Cartesian coordinate system. The intensity, analogous to luma, is the vertical axis of the polar system. The hue is the angle and the saturation is the distance out from the axis. HSI is more intuitive to manipulate colors as opposed to the RGB space. For example, in the HSI space, if you want to change red to pink, you decrease the saturation. In the RGB space, what would you do? My point exactly. In the HSI space, if you wanted to change the color from purple to green, you would adjust the hue. Take a guess what you would have to do in the RGB space. However, the key thing to remember, as with all color spaces, is that it's just a way to represent a color-nothing more, nothing less. 
HSL This is similar to HSI, except that HSL stands for Hue, Saturation and Lightness. 
HSV This is similar to HSI, except that HSV stands for Hue, Saturation and Value. 
HSYNC Check out the horizontal sync definition. 
hue  An attribute of color perception. Red, green, blue form the color model used, in varying proportions, to produce all the colors displayed in video and on computer screens. Also called a color phase. See also vectorscope.
Huffman Coding Huffman coding is a method of data compression. It doesn't matter what the data is -- it could be image data, audio data, or whatever. It just so happens that Huffman coding is one of the techniques used in JPEG, MPEG, H.261, and H.263 to help with the compression. This is how it works. First, take a look at the data that needs to be compressed and create a table that lists how many times each piece of unique data occurs. Now assign a very small code word to the piece of data that occurs most frequently. The next largest code word is assigned to the piece of data that occurs next most frequently. This continues until all of the unique pieces of data are assigned unique code words of varying lengths. The idea is that data that occurs most frequently is assigned a small code word, and data that rarely occurs is assigned a long code word, resulting in space savings. 
i frame In inter-frame compression schemes (e.g., MPEG), the key frame or reference video frame that acts as a point of comparison to p- and b-frames, and is not reconstructed from another frame. Contrast b frame and p frame.
i.LINK The Sony trade name for IEEE 1394. 
I/O device  Input/output equipment used to send information or data signals to and from an editing computer. 
IEC 60461 Defines the longitudinal (LTC) and vertical interval (VITC) timecode for NTSC and PAL video systems. LTC requires an entire field time to transfer timecode information, using a separate track. VITC uses one scan line each field during the vertical blanking interval. Purchase the specification. Also see SMPTE 12M. 
IEC 60958 Defines a serial digital audio interface for consumer (SPDIF) and professional applications. Purchase the specification. 
IEC 61834 Defines the DV (originally the "Blue Book") standard. Purchase the specification. Also see SMPTE 314M. 
IEC 61880 Defines the widescreen signaling (WSS) information for NTSC video signals. WSS may be present on lines 20 and 283. Purchase the specification. 
IEC 61883 Defines the methods for transferring data, audio, DV and MPEG-2 data over IEEE 1394. Purchase the specification. 
IEC 62107 Defines the Super VideoCD standard. Purchase the specification. 
IEEE Abbreviation for the Institute of Electrical and Electronic Engineers; the organization that sets many of the electronic-industry standards.
IEEE 1394 A high-speed "daisy-chained" serial interface. Digital audio, video, and data can be transferred with either a guaranteed bandwidth or a guaranteed latency. It is hot-pluggable, and uses a small 6-pin or 4-pin connector, with the 6-pin connector providing power. 
iLink Sony's name for their IEEE 1394 interface. 
Illegal Video Some colors that exist in the RGB color space can't be represented in the NTSC and PAL video domain. For example, 100% saturated red in the RGB space (which is the red color on full strength and the blue and green colors turned off) can't exist in the NTSC video signal, due to color bandwidth limitations. The NTSC encoder must be able to determine that an illegal color is being generated and stop that from occurring, since it may cause over-saturation and blooming. 
Image Buffer For all practical purposes, an image buffer is the same as a frame buffer. An image is acquired and stored in the image buffer. Once it is in the image buffer, it can typically be annotated with text or graphics or manipulated in some way, just like anything else in a frame buffer. 
Image Compression Image compression is used to reduce the amount of memory required to store an image. For example, an image that has a resolution of 640 x 480 and is in the RGB color space at 8 bits per color, requiring 900 KB of storage. If this image can be compressed at a compression ratio of 20:1, then the amount of storage required is only 45 KB. There are several methods of image compression, but the most popular are JPEG and MPEG. H.261 and H.263 are the video compression standards used for video conferencing. 
image enhancer A device used to sharpen transition lines in a video picture. 
Image Independence  See HIIP. 
Improved Definition Television IDTV is different from HDTV. IDTV is a system that improves the display on TVs by adding processing in the TV; standard NTSC or PAL signals are transmitted. 
IN point  The starting point of an edit. Also called a mark IN. See also mark IN/OUT, OUT point. 
in the can Describes a scene or program which has been completed. Also, "that's a wrap". 
in-point In-points (and outpoints) are used in editing to determine where and how edits are inserted on the record clip, and to determine what part of a source clip is used in an insert or overwrite. 
initializing  The setting of the computer edit program to proper operating conditions at the start of the editing session. 
ink numbers  The frame identification numbers used to conform a film work print. Film Composer cut lists and change lists reference ink numbers. 
insert edit An electronic edit in which the existing control track is not replaced during the editing process. The new segment is inserted into program material already recorded on the video tape. Recording new video and/or audio material onto a prerecorded (or striped) tape. Insert edits can be made in any order, unlike assemble edits, which must be made sequentially.
insertion gain The gain (or loss) in overall signal amplitude introduced by a piece of equipment in the signal path. Insertion gain is expressed as a percent (V out-V in) / (V in x 100).
Intensity This is the same thing as brightness. 
inter-frame compression A compression scheme, such as MPEG, that reduces the amount of video information by storing only the differences between a frame and those preceding it. 
inter-positive A colour master positive print.
Intercast A method developed by Intel for transmitting web pages during the vertical blanking interval of a NTSC or PAL video signal. It is based on NABTS for (M) NTSC systems. 
interface  1. The computer software or hardware used to connect two functions or devices. 2. The program access level at which a user makes selections and navigates a given system. See also GUI. 
interlace The manner in which a television picture is composed, scanning alternate lines to produce one field, approximately every 1/60 of a second in NTSC. Two fields comprise of one television frame. Therefore, the NTSC television frame rate of approximately 30 fps. A process in which the picture is split into two fields by sending all the odd numbered lines to field one and all the even numbered lines to field two. Field one is then displayed first, followed by field 2. This was necessary in the early days of TV when there was not enough bandwidth to send a complete frame fast enough to create a non-flickering image.
interlace scanning A display technique in which each TV picture, or frame, is produced using two sequential fields. One field contains the off-numbered lines, and the other the even-numbered lines. The tv tube is scanned twice, with the lines of the two fields interleaved, or interlaced. The technique eliminates visible flicker which can be annoying at low frame rates. A method of creating a video image by scanning only the odd numbered lines on the screen in one pass, then the even numbered lines in the next pass. Two passes are therefore required to create a complete frame of video. Non-interlaced scanning displays the odd and even lines sequentially so that the complete image is displayed in one pass. NTSC and PAL displays are interlaced, VGA displays are non-interlaced.
Interlaced An interlaced video system is one where two interleaved fields are used to generate one video frame. Therefore, the number of lines in a field is one-half of the number of lines in a frame. In NTSC, there are 262.5 lines per field (525 lines per frame), while there are 312.5 lines per field (625 lines per frame) in PAL. Each field is drawn on the screen consecutively -- first one field, then the other. 
interlacing The system developed for early television and still used in standard television displays. To compensate for limited persistence, the electron gun used to illuminate the phosphors coating the inside of the screen interlaces alternately draws even and then odd horizontal lines. By the time the even lines are dimming, the odd lines are illuminated. We perceive the interlaced fields of lines as complete pictures. 
intermediates General term for colour masters and dupes.
Interpolation Interpolation is a mathematical way of generating additional information. Let's say that an image needs to be scaled up by a factor of two, from 100 samples to 200 samples. The "missing" samples are generated by calculating (interpolating) new samples between two existing samples. After all of the "missing" samples have been generated -- presto! -- 200 samples exist where only 100 existed before, and the image is twice as big as it used to be. 
intra-frame compression Compression that reduces the amount of video information in each frame on a frame-by-frame basis. 
inverse non-additive mix A mixing process that compares the colour values of the corresponding pixels in the two source clips, and assigns the higher value to the corresponding pixel in the output clip.
IRE A relative unit of measure on a waveform monitor (introduced by the Institute of Radio Engineers). One IRE equals 1/140th of the composite video signal's peak-to-peak voltage.
IRE Unit An arbitrary unit used to describe the amplitude characteristics of a video signal. White is defined to be 100 IRE and the blanking level is defined to be 0 IRE. 
IRIX A version of the UNIX operating system that is used by sgi..
ISA slot Connection slot to a type of computer expansion bus found in most computers. It is larger in size than teh PCI slots found on most Pentium based computers and provides connections to teh slower ISA bus. ISDN, (Integrated Services Digital Network)
ISMA Abbreviation for the Internet Streaming Media Alliance. ISMA is a group of industry leaders in content management, distribution infrastructure and media streaming working together to promote open standards for developing end-to-end media streaming solutions. The ISMA specification defines the exact features of the MPEG-4 standard that have to be implemented on the server, client and intermediate components to ensure interoperability between the entire streaming workflow. Similarly, it also defines the exact features and the selected formats of the RTP, RTSP, and SDP standards that have to be implemented. The ISMA v1.0 specification defines two hierarchical profiles. Profile 0 is aimed to stream audio/video content on wireless and narrowband networks to low-complexity devices, such as cell phones or PDAs, that have limited viewing and audio capabilities. Profile 1 is aimed to stream content over broadband-quality networks to provide the end user with a richer viewing experience. Profile 1 is targeted to more powerful devices, such as set-top boxes and personal computers. 
ISO  1. Isolation reel. In multicamera production, the source reel for the separate (isolated) recording of a single camera, alongside simultaneous recordings of the other cameras and a switched line feed. 2. International Organization for Standardization
ITU-R 601  The standard for standard-definition component digital video, published by the International Telecommunication Union as ITU-R BT.601-5 (formerly CCIR-601). This standard defines digital component video as it is derived from NTSC and PAL. It forms the basis for HDTV formats as well.
ITU-R BT.xxx See BT.xxx. Jitter Short-term variations in the characteristics (such as frequency, amplitude, etc.) of a signal. 
jaggies  The rough edges around computer-generated graphic objects and titles. 
jam sync Process of synchronizing a secondary time code generator with a selected master time code, i.e., synchronizing the smart slate and the audio time code to the same clock.
jam syncing  The process of synchronizing a secondary timecode generator with a selected master timecode. 
jogging  See stepping. 
JPEG JPEG stands for Joint Photographic Experts Group. However, what people usually mean when they use the term "JPEG" is the image compression standard they developed. JPEG was developed to compress still images, such as photographs, a single video frame, something scanned into the computer, and so forth. You can run JPEG at any speed that the application requires. For a still picture database, the algorithm doesn't have to be very fast. If you run JPEG fast enough, you can compress motion video -- which means that JPEG would have to run at 50 or 60 fields per second. This is called motion JPEG or M-JPEG. You might want to do this if you were designing a video editing system. Now, M-JPEG running at 60 fields per second is not as efficient as MPEG-2 running at 60 fields per second because MPEG was designed to take advantage of certain aspects of motion video. 
KEM roll  The roll of film used on a KEM flatbed editing system. A KEM roll combines multiple takes onto a single roll (a work print, not a negative). The maximum length of a KEM roll is 1000 ft (35mm). 
kerning  The spacing between text characters in print media, such as titles. 
key  To combine a selected image from one source with an image from another source. See also chroma key. 
key color  The solid color used to key. 
key numbers  The original frame identification numbers applied by the film manufacturers to the film stock. Key numbers are used by the negative cutter to conform the film negative. Film Composer cut lists and change lists reference key numbers. 
key source The image that contains the colours or luminance values on which you key to create a chroma or luminance key effect.
keyer A tool that you use to create a composite from a clip from a background and foreground clip by using an input key-in clip to determine how the clips are combined. You use the input key-in clip to create a black and white matte that defines which areas of the foreground and background clips are used in the result clip.
keyframe A point on an animation curve that represents a value assigned to a specific frame. For example, if you change the position of an object in an image, you create a keyframe that marks the change on an animation curve for object translation or motion.
keyframing The process of creating an animated clip wherein by selecting a beginning image and an ending image the software automatically generates the frames in between. See also, tweening. 
keying The replacing of part of one television image with video from another image. Also called blue screen. See also, chroma key. 
Keykode  A trademark of Eastman Kodak Company. A film-marking system that applies optical information identifying the film stock and footage at the edge of the film during manufacture. 
keykode numbers reader Device attached to a telecine or part of a bench logger which read Keykode number bar code from motion picture film and provides electronic output t a decoder.
kilobyte One thousand bytes. Actually 1024 bytes because of the way computer math works out.
kilobyte (KB)  Approximately one thousand bytes (1024 bytes) of information. 
kilohertz (kHz)  One thousand cycles per second. See also hertz (Hz). 
kinescope A film recording of a video image displayed on a specially designed television monitor. Also called "Kine". Only means of recording TV programs before video recorders and tape were invented.
L-cut  See overlap edit. 
LANC The protocol defined by Sony for enabling external control of video devices and accessing status information from the device. Also referred to as Control-L. See also, Vbox. 
latent image the invisible image formed in a camera or printer by the action of light on a photographic emulsion.
latitude In a photographic process, the range of exposure over which substantially correct reproduction is obtained. When the process is represented by and H and D curve, the latitude is the projection on the exposure axis of that part of the curve which approximates a straight line with-in the tolerance permitted for the purpose at hand.
layback Transferring the finished audio track back to the master video tape. LTC (Longitudinal Time Code)
layer 1. A combination of a front and matte clip on top of a background clip. You can work with multiple layer on top of a background clip. 2. Images, objects, scenes, and paint stacked on top of each other.
layered tracks  The elements of an effect created by combining two or more tracks in a specified way, such as nesting one track as a layer within another. 
leader Any film or strip of material used for threading a motion picture machine. Leader may consist of short lengths of blank film attached to the ends of a print to protect the print from damage during the threading of a projector, or it may be a long length of any kind of film which is used to establish the film path in a processing machine before the use of the machine for processing film.
letterbox Placing a wide screen image on a conventional TV by placing black bands at the top and bottom of the screen.
level  "A quantitative measure of a video or an audio signal. A low level indicates the darker portions in video and the soft or quieter portions in audio; conversely, a high level indicates a brighter video image or a louder audio signal. The level of audio signal correlates directly with the volume of reproduced sound. "
lift  To remove selected frames from a sequence and leave black or silence in the place of the frames. 
limiter A device that prevents the voltage of an audio or video signal from exceeding a specified level, to prevent distortion or overloading of the recording device. 
line feed  A recording or live feed of a program that switches between multiple cameras and image sources. Also known in sitcom production as the director's cut. 
Line Store A line store is a memory used to hold one scan line of video. If the horizontal resolution of the active display is 640 samples and RGB is used as the color space, the line store would have to be 640 locations long by 3 bytes wide. This amounts to one location for each sample and each color. Line stores are typically used in filtering algorithms. For example, a comb filter is made up of one or more line stores. 
Line-Locked Clock A design that ensures that there is always a constant number of samples per scan line, even if the timing of the line changes. 
linear 1. A mode of interpolation or extrapolation of an animation curve in which the control points are either connected by straight lines (interpolation) or the curve is continued in a straight line before the first control point and after the last control point (extrapolation). 2. Editing based on the sequence of frames recorded on a tape.
linear editing  A type of tape editing in which you assemble the program from beginning to end. If you require changes, you must rerecord everything downstream of the change. The physical nature of the medium (for example, analog videotape) dictates how you place material on the medium. See also nonlinear editing. 
Linear Time Code, Longitudinal Time Code, (LTC) Time code that is generally encoded as an audio signal onto a linear audio track of track on a video tape. This type of time code can be read only while the tape is moving.
Linearity Linearity is a basic measurement of how well an ADC or DAC is performing. Linearity is typically measured by making the ADC or DAC attempt to generate a linearly increasing signal. The actual output is compared to the ideal of the output. The difference is a measure of the linearity. The smaller the number, the better. Linearity is typically specified as a range or percentage of LSBs (Least Significant Bits). 
liquid gate A printing system in which the original is immersed in a suitable liquid at the moment of exposure in order to reduce the effect of surface scratches and abrasions.
load  1. A roll of film stock ready to be placed in the camera for photography. A 1000-foot load is a common standard. 2. A group of multicamera reels shot at the same time, sharing the same timecode, and numbered accordingly.
locator  A mark added to a selected frame to qualify a particular location within a sequence. User-defined comments can be added to locators. 
Locked When a PLL is accurately producing timing that is precisely lined up with the timing of the incoming video source, the PLL is said to be "locked". When a PLL is locked, the PLL is stable and there is minimum jitter in the generated sample clock. 
log  1. To enter information about your media into bins at the beginning of the editing process. Logging can be done automatically or manually. 2. See shot log.
logical volume A description of the memory blocks disks used for the framestore.
Longitudinal Timecode Timecode information is stored on a separate track from the video, requiring an entire field time to store or read it. 
longitudinal timecode (LTC) A timecode recorded as an audio signal on the address or the audio track of a video tape, or on a track of audio tape. LTC can be read at high shuttle speeds, enabling timecode readers to stay in sync during rewind or fast forward. Contrast with SMPTE timecode and vertical interval timecode. 
lookup table, (LUT) Files used to convert colour information in an image.
looping A term that indicates a high-impedance device is permanently connected in parallel to a video source. 
Lossless Lossless is a term used with image compression. Lossless image compression is when the decompressed image is exactly the same as the original image. It's lossless because you haven't lost anything. 
Lossy Lossy image compression is the exact opposite of lossless. The regenerated image is different from the original image. The differences may or may not be noticeable, but if the two images are not identical, the compression was lossy. 
low frequency amplitude distortion A variation in amplitude level that occurs as a function of frequencies below 1 MHz.
low key A scene is reproduced in a low key if the tone range of the reproduction is largely in the high density portion of the H and D scale of the process.
Lowpass Filter A circuit that passes frequencies below a specific frequency (the cutoff frequency). Frequencies above the cutoff frequency are reduced in amplitude to eliminate them. 
LS  Long shot. 
Luma As mentioned in the definition of chroma, the NTSC and PAL video systems use a signal that has two pieces: the black and white part, and the color part. The black and white part is the luma. It was the luma component that allowed color TV broadcasts to be received by black and white TVs and still remain viewable. 
lumakey When keying one image onto another, if the composition is based on a combination of luminance and brightness values, it constitutes a lumakey. 
luminance The black and white, or brightness, part of a component video signal. The monochrome (high resolution) portion of a video signal. The brightness information in the TV picture. The luminance signal amplitude varies in proportion to the brightness of the televised scene and is therefore capable of producing a complete monochrome picture.
luminance nonlinearity The degree to which the luminance signal gain is affected by changes in the luminance level.
luminence key An effect that makes portions of a foreground image fully or partially transparent based on the luminance of that image (or another source), so that an underlying image can show through.
M & E track  The common designation for a single sound track containing music and sound effects but not dialog. 
magnetic track  A sound track recorded on magnetic sound recording film. 
mark in To select the first frame of a clip.
mark IN/OUT  1. The process of entering the start and end timecodes for a clip to be edited into a sequence. 2. The process of marking or logging timecode numbers to define clips during a logging, recording, or digitizing session. See also IN point, OUT point. 
mark out To select the last frame of a clip. 
mask  1. In film, a border placed over an image with a 3:4 aspect ratio to create the look of an another aspect ratio, such as wide-screen. 2. See alpha channel.
master  The tape resulting from editing. The finished program. 
master clip  In the bin, the media object that refers to the media files recorded or digitized from tape or other sources. See also clip, subclip. 
master shot  The shot that serves as the basic scene, and into which all cutaways and closeups will be inserted during editing. A master shot is often a wide shot showing all characters and action in the scene. 
master/slave  A video-editing process in which one or more decks (the slaves) are set to imitate the actions of another deck (the master). 
match Matching individual frames in assembled clips to the corresponding frames in the source clip.
match frame An edit in which the source and record tape pick up exactly where they left off. Often used to extend a previous edit. Also called a "tracking edit".
match-frame edit  An edit in which the last frame of the outgoing clip is in sync with the first frame of the incoming clip, such that the incoming clip is an extension of the outgoing clip. 
matchback  The process allowing you to generate a film cut list from a 30-fps video project that uses film as the source material. 
matchback conversion  The conversion from film to video frame rates. 
mathematically lossless compression A method of compressing video without losing image quality. The video is identical to uncompressed video, but requires less disk space.
matte The cutout that is used in the creation of a composite image. The solid black part of the matte represents the area of the resulting image where the background appears. The solid white part of the matte represents that area of the result image where the foreground appears. A black and white high contrast image that suppresses or cuts a hole in the background picture to allow the picture the matte was made from to seamlessly fit in the hole. An opaque outline which limits the exposed area of a picture, either as a cut-out object in front of the camera or as a silhouette on a another strip of film.
matte key  A video effect comprised of three components: the background video, the foreground video, and the matte or alpha channel (black and white or grayscale silhouette) that allows one portion of the image to be superimposed on the other. 
media  The video, audio, graphics, and rendered effects that can be combined to form a sequence or presentation. 
Media 100 A non-linear editing system that uses its own properitary software. Often used with Adobe After Effects. 
media data  Data from a media source. Media data can be: 1. Analog data: film frames, Nagra tape audio, or videotape video and audio. 2. Digital data: either data that was recorded or digitized such as video frame data and audio samples, or data created in digital form such as title graphics, DAT recordings, or animation frames.
media files  Files containing the compressed digital audio and video data needed to play Avid clips and sequences. 
media sample data  See safe color limiting. 
megabyte 1 million bytes.
megahertz (MHz)  One million cycles per second. See also hertz (Hz), kilohertz (kHz). 
MESECAM A technique of recording SECAM video. Instead of dividing the FM color subcarrier by four and then multiplying back up on playback, MESECAM uses the same heterodyne conversion as PAL. 
mesh A grid that is placed over an image during morphing or warping.
MHP See Multimedia Home Platform. 
MIDI  Musical Instrument Digital Interface. A standard protocol that allows a user to control electronic music equipment from a PC. 
MIDI timecode A system for timed device control through MIDI protocols. The importance of MIDI timecode in video post production has increased due to the increased use of personal computers for video production. Contrast SMPTE timecode. 
midtones Midlevel grays in an image.
MII format  A component videotape format created by Panasonic in an effort to compete with Sony Betacam. MII is an extension of the VHS consumer format as Sony Betacam is an extension of the Betamax home video technology. 
Miro Instant video An edit mode in Adobe Premiere for Windows—specifically for DC30 users—that allows video to be streamed out of a DC30 capture card. 
mix  1. A transition from one video source to another in a switcher. 2. The product of a recording session in which several separate sound tracks are combined through a mixing console in mono or stereo.
mixdown audio  The process that allows the user to combine several tracks of audio onto a single track. 
MJPEG Acronym for Motion JPEG; a sequence of JPEG images played by a video player. 
Modulator A modulator is basically a circuit that combines two different signals in such a way that they can be pulled apart later. What does this have to do with video? Let's take the NTSC system as an example, although the example applies equally as well to PAL. The NTSC system may use the Y'IQ or Y'UV color space, with the I and Q or U and V signals containing all of the color information for the picture. Two 3.58-MHz color subcarriers (90 degrees out of phase) are modulated by the I and Q or U and V components and added together to create the chroma part of the NTSC video. 
module board Printed circuit board and mounted components that is attached to the base board using screws and spacers.
moire Visual disturbance caused by the interference of similar frequencies, or the wavy effect produced by the convergence of lines. Compare aliasing. 
monitor  1. In video, a picture tube and associated circuitry without tuner or audio sections. The monitor includes the display of source media, clips, and sequences. In Avid products, virtual monitors are displayed on the screen in which source media, clips, and sequences can be edited. 2. In audio, to monitor specific audio tracks and channels, or another name for the speakers through which sound is heard.
Monochrome A monochrome signal is a video source having only one component. Although usually meant to be the luma (or black-and-white) video signal, the red video signal coming into the back of a computer display is monochrome because it only has one component. 
monochrome signal A single color-video signal. A monochrome signal is usually black and white, but can be the luminance portion of a composite- or component-color signal. 
Monotonic This is a term that is used to describe ADCs and DACs. An ADC or DAC is said to be monotonic if for every increase in input signal, the output increases. Any ADC or DAC that is nonmonotonic -- meaning that the output decreases for an increase in input -- is bad! Nobody wants a nonmonotonic ADC or DAC. 
MOS Slang for silent shooting. From the slang German "mit out sprechen" ("without talking" The correct German phrase would be "ohne sprechen".)
mosaic An effect that "blurs" an image by copying pixels into adjacent pixels both horizontally and vertically. This gives the image a blockly appearance, often used to hide people's identities on television. motion blur
motion effect  An effect that speeds up or slows down the presentation of media in a track. 
Motion Estimation Motion estimation is trying to figure out where an object has moved to from one video frame to the other. Why would you want to do that? Well, let's take an example of a video source showing a ball flying through the air. The background is a solid color that is different from the color of the ball. In one video frame the ball is at one location and in the next video frame the ball has moved up and to the right by some amount. Now let's assume that the video camera has just sent the first video frame of the series. Now, instead of sending the second frame, wouldn't it be more efficient to send only the position of the ball? Nothing else moves, so only two little numbers would have to be sent. This is the essence of motion estimation. By the way, motion estimation is an integral part of MPEG, H.261, and H.263. 
motion jitters Jerky movements in a clip, often caused by gate slip when film is converted into video.
motion JPEG, (M-JPEG) A compresion and storage standard used for motion video. Teh JPEG compression process is applied to each video field, in succession.
motion path A bspline displayed in the image window and a timing curve displayed in the animation curve window that defines the translation, or motion, of an object, camera, camera point of interest, displayed axes, or light sources.
motion stabilization A feature used to eliminate the wobble in the video taken with a hand-held camera. The After Effects Production Bundle includes a motion stabilizer. 
motion tracking  The process of generating position information that describes motion in a clip, for example, the changing position of a moving vehicle. You use motion tracking data to control the movement of effects. See also stabilization. 
Moto DV Playback An edit mode in Premiere—specifically for MotoDV studio users— that allows video to be streamed out of a MotoDV capture card. 
movie-2 bus or movie-2 bus connector Over the top connector used for high-speed data transfer. These two terms refer to the assembled component, which consists of a printed circuit board (backplane) with attached connectors.
MPEG, (Moving Picture Experts Group) Moving Picture Experts Group. A standard for compressing moving pictures. MPEG uses the similarity between frames to create a sequence of I, B, and P frames. Only the I frame contains all the picture data. The B and P frames only contain information relating to changes since the last I frame. MPEG 1 uses a data rate of 1.2 Mbps (Mega Bits per Second), the speed of CD-ROM. MPEG 2 supports much higher quality with a data rate (also called bit rate) of from 1.2 to15 Mpbs. MPEG 2 is the format most favored for video on demand, DVD, and is the format for transmitting Digital Television.
MPEG-1 MPEG-1 (ISO/IEC 11172) was the first MPEG standard defining the compression format for real-time audio and video. The video resolution is typically 352 x 240 or 352 x 288, although higher resolutions are supported. The maximum bitrate is about 1.5 Mbps. MPEG-1 is used for the Video CD format. 
MPEG-1 The international compression standard for the conversion of analog motion video to digital motion video that includes both video and audio data. MPEG meets the needs CD-ROM and video-on-demand applications. Actual compression over uncompressed digital video is about 100:1. MPEG-1 was initially designed to deliver near-broadcast quality video through a standard speed CD-ROM. Playback of MPEG-1 video requires either a software decoder coupled with a high-end computer or a hardware decoder. 
MPEG-2 MPEG-2 (ISO/IEC 13818) extends the MPEG-1 standard to cover a wider range of applications. Higher video resolutions are supported to allow for HDTV applications, both progressive and interlaced video are supported. MPEG-2 is used for the DVD - Video and SVCD formats, and also forms the basis for digital SDTV and HDTV. 
MPEG-2 MPEG-2 is an extension of the MPEG-1 compression standard designed to meet the requirements of television broadcast studios. MPEG-2 is the broadcast quality video found on DVDs and requires a hardware decoder (e.g., a DVD-ROM player) for playback. 
MPEG-3 MPEG-3 was originally targeted for HDTV applications. This was incorporated into MPEG-2, so there is no MPEG-3 standard. 
MPEG-4 MPEG-4 (ISO/IEC 14496) supports an object-based approach, where scenes are modeled as compositions of objects, both natural and synthetic, with which the user may interact. Visual objects in a scene can be described mathematically and given a position in a two- or three-dimensional space. Similarly, audio objects can be placed in a sound space. Thus, the video or audio object need only be defined once; the viewer can change his viewing position, and the calculations to update the audio and video are done locally. Classical "rectangular" video, as from a camera, is one of the visual objects supported. In addition, there is the ability to map images onto computer-generated shapes, and a text-to-speech interface. Although well-known as a low bitrate, low resolution solution for wireless devices, MPEG-4 also supports HDTV resolutions and studio applications. MPEG-4 offers bit rates of about one-half those used for MPEG-2 of similar video quality. "DVD quality" is achievable at about 1.5-2 Mbps, with "HDTV quality" at about 7 Mbps. Thus, a 6 MHz cable channel can support up to 24 SDTV channels of MPEG-4 content instead of 12 channels of MPEG-2 content. H.26L, a next-generation video codec, is also being worked on, with the intent of it being part 10 of the MPEG-4 standard. 
MPEG-7 MPEG-7 standardizes the description of multimedia material (referred to as metadata), such as still pictures, audio, and video, regardless if locally stored, in a remote database, or broadcast. Examples are finding a scene in a movie, finding a song in a database, or selecting a broadcast channel. The searcher for an image can use a sketch or a general description. Music can be found using a "query by humming" format. 
MTS Multichannel Television Sound. A generic name for various stereo audio implementations, such as BTSC and Zweiton. 
MU/FX or MUFX  See M & E track. 
multicamera  A production or scene that is shot and recorded from more than one camera simultaneously. 
multimedia The combining of different computer-based media—usually audio, text, graphics, and animation—into a single presentation. Multimedia presentations are typically played back directly from the computer. 
Multipass Encoding True multipass encoding is currently available only for WM8 and MPEG-2. An encoder supporting multipass will, in a first pass, analyze the video stream to be encoded and write down a log about everything it encounters. Let's assume we have a short clip that starts out in a dialog scene where we have few cuts and the camera remains static. Then it leads over to a karate fight with lots of fast cuts and a lot of action (people flying through the air, kicking, punching, etc.). In regular CBR, encoding every second gets more or less bitrate (it's hard to stay 100% CBR but that's a detail) whereas in multipass VBR mode the encoder will use the bitrate according to his knowledge about the video stream, i.e. the dialog part gets the available bitrate and the fighting scene gets allotted more bitrate. The more passes, the more refined the bitrate distribution will be. In single pass VBR, the encoder has to base his decisions on where to use how much bitrate solely on the knowledge of the stuff it previously has encoded. 
multiple B-roll  A duplicate of the original source tape, created so that overlays can be merged onto one source tape. 
multiplexer Device or circuit used for mixing television signals to a single video recorder.
multitrack  A magnetic tape or film recorder capable of recording more than one track at a time.
NAB  National Association of Broadcasters. 
NABTS North American Broadcast Teletext Specification (EIA-516).  This is also ITU-R BT.653 525-line system C teletext. However, the NABTS specification goes into much more detail. 
Nagra  A brand of audiotape recorder widely used in the film production and postproduction industries. 
National Television Standards Committee, (NTSC) A U.S. engineering groups that developed a black and white TV standard in the early 194-s and a colour standard in the early 1950s. Also used to indicate the system itself. The television and video standard in use in North America, Japan and parts of South America. Consists of 525 horizontal lines at a field rate of 60 fields per second. (Two fields equals one complete Frame). Only 487 of these lines are used for picture. The rest are used for sync or extra information such as VITC and Closed Captioning.
negative  "1. A film element in which the light and dark areas are reversed compared to the original scene; the opposite of a positive. 2. A film stock designed to capture an image in the form of a negative."
neutral colors The range of grays, from black to white, that have no color. For neutral color areas, RGB signals are of equal value. In color difference formats, the color difference signals are zero. 
NexTView An electronic program guide (EPG) based on ETSI ETS 300 707. 
NICAM 728 A technique of implementing digital stereo audio for PAL video using another audio subcarrier. The bit rate is 728 kbps. It is discussed in BS.707 and ETSI EN 300 163. NICAM 728 is also used to transmit non-audio digital data in China. 
node An object and its axis as represented in schematic view.
noise  1. In video, an aberration that appears as very fine white specks (snow) and that increases over multiple generations. 2. In audio, a sound that is usually heard as a hiss.
noise reduction Usually performed by an electronic device, the attempted reduction of noise during recording or playback. 
non-additive mix A mixing process that compares the colour values of the corresponding pixels in the two source clips and assigns the higher value to the corresponding pixel in the output clip.
non-drop frame A type of SMPTE time code that continuously counts a full 30 frames per second. As a result, non-drop frame time code does not exactly match real time.
non-drop-frame timecode  "An SMPTE timecode format that continuously tracks NTSC video at a rate of 30 fps without dropping frames to compensate for the actual 29.97-fps rate of NTSC video. As a result, non-drop-frame timecode does not coincide with real time. Non-drop-frame timecode is recorded with colons between the digits; for example, 1:00:10:02. Compare with drop-frame timecode. "
non-linear editing Random-access editing of video and audio on a computer, enabling edits to be processed and reprocessed at any point in the timeline, at any time. Traditional videotape editors are linear because they require editing video sequentially, from beginning to end. 
noncomposite video  A video signal that does not contain horizontal and vertical sync pulses. 
Noninterlaced This is a method of scanning out a video display that is the total opposite of interlaced. All of the lines in the frame are scanned out sequentially, one right after the other. The term "field" does not apply in a noninterlaced system. Another term for a noninterlaced system is progressive scan. 
nonlinear  Pertaining to instantaneous random access and manipulation of any frame of material on any track and on any layer of an edit sequence. 
NTFS  New Technology File System. A file system used on Windows computers. 
NTSC  National Television Standards Committee. The group that established the color television transmission system used in the United States, using 525 lines of information scanned at a rate of approximately 30 fps. See also PAL, SECAM.
NTSC 4.43 This is a NTSC video signal that uses the PAL color subcarrier frequency (about 4.43 MHz). It was developed by Sony in the 1970s to more easily adapt European receivers to accept NTSC signals. 
NTSC color bars The pattern comprising eight equal-width color bars generated by an NTSC generator. The color bars are used for calibration and as a reference to check transmission paths, signal phase, recording and playback quality, and monitor alignment. 
NTSC composite The video signal standard proposed by the NTSC and adopted by the FCC for broadcast television in the United States. The signal is an interlaced composite video signal of 525 lines and 60 fields per second (30 frames per second), with a bandwidth limited to 4 MHz to fit into a 6 MHz broadcast television channel without interfering with adjacent channels. 
NTSC RGB Interlaced red, green, and blue video signals timed to NTSC standards. Refers to the three monochrome signals that represent the primary colors of an image. Contrast with component video. 
nVOD Abbreviation for near-video-on-demand. See video-on-demand. 
off-line Preliminary editing done on relatively low-cost editing systems, usually to provide an EDL for final on-line editing and assembly of the finished show.
off-line edit Roughcut editing used to produce an Edit Decision List.
off-line editing A preliminary edit generally performed on an inexpensive editing system using video tape copies of the original master tapes. Off-line editing enables editors to make decisions and obtain approvals before making more expensive on-line edits. 
off-line editor A low resolution, usually computer and disk based edit system in which the creative editing decisions can be made at lower cost and often with greater flexibility than in an expensive fully equipped on-line bay.. 
offset 1. The horizontal and vertical displacement of a clip. 2. Reference numbers that indicate the change, in terms of frames, that takes place when you trim.
OMFI  Open Media Framework Interchange, a registered trademark of Avid Technology, Inc. A standard format for the interchange of digital media data among heterogeneous platforms. The format is designed to encapsulate all the information required to interchange a variety of digital media, such as audio, video, graphics, and still images as well as the rules for combining and presenting the media. The format includes rules for identifying the original sources of the digital media, and it can encapsulate both compressed and uncompressed digital media data. 
on-line Final editing or assembly using master tapes to produce a finished program ready for distribution. Often preceded by off-line editing, but in some cases programs go directly to the on-line editing suite. Usually associated with high-quality computer editing and digital effects.
on-line edit Final edit, using the original source material and an Edit Decision List (EDL). The online edit produces a finished product ready for distribution.
on-line editing The final linear editing of the original master tapes to produce the finished piece. An on-line edit suite generally includes all the necessary high-end devices (e.g., a switcher, TBC, character generator, etc.). 
on-line editor  An editing system where the actual video master is created. An on-line bay usually consists of an editing computer, video switcher, audio mixer, 1 or more channels of DVE, character generator, and several video tape machines.
one light  A telecine transfer or film print produced with a single setting of color correction values. One light is the simplest, fastest, and least costly type of transfer. 
Open Media Framework Interchange, (OMF) A standard file format used for the exchange of digital multimedia data between applications and across platforms.
Open Subtitles See subtitles. 
optical effects Trick shots prepared by the use of an optical printer in the laboratory, especially fades and dissolves.
opticals  The effects created in a film lab through a process called A-roll and B-roll printing. This process involves a specified manipulation of the film negative to create a new negative containing an effect. The most common opticals used in film editing are fades, dissolves, and superimpositions. 
orbit The rotation of the camera eye around the point of interest.
origin  A reference point for measuring sections of recorded or digitized sample data. A file mob value for the start position in the media is expressed in relation to the origin. Although the same sample data can be rerecorded or redigitized, and more sample data might be added, the origin remains the same so that composition source clips referencing it remain valid. 
original negative  The actual film stock used in the camera to photograph a scene. 
OUT point  The end point of an edit, or a mark on a clip indicating a transition point. Also called a mark OUT. See also IN point, mark IN/OUT. 
out-take A take of a scene which is not used for printing or final assembly in editing.
outtake  A take that is not selected for inclusion in the finished product. 
overcoat A thin layer of clear or dyed gelatin sometimes applied on top of the emulsion surface of a film to act as a filter layer or to protect the emulsion from abrasion during exposure and processing.
overlap edit  An edit in which the audio and video signals are given separate IN points or OUT points, so the edit takes place with one signal preceding the other. This does not affect the audio and video synchronization. See also L-cut, delay edit, or split edit. 
Oversampled VBI Data See raw VBI data. 
Overscan When an image is displayed, it is "overscanned" if a small portion of the image extends beyond the edges of the screen. Overscan is common in TVs that use CRTs to allow for aging and variations in components, temperature and power supply. 
overwrite  An edit in which existing video, audio, or both is replaced by new material. See also splice. 
overwrite edit The addition of a source clip into a record clip, where the record clip edit sequence does not ripple (the duration does not change). The source clip overwrites an equal number of frames on the edit sequence.
oxide  A metallic coating on videotape or magnetic film that is magnetized during the recording process.
p-frame Predicted frame. The frame in an MPEG sequence created by predicting the difference between the current frame and the previous one. 
PAL  Phase Alternating Line. A color television standard used in many countries. PAL consists of 625 lines of information scanned at a rate of 25 fps. See also NTSC, SECAM. 
PAL 60 This is a NTSC video signal that uses the PAL color subcarrier frequency (about 4.43 MHz) and PAL-type color modulation. It is a further adaptation of NTSC 4.43, modifying the color modulation in addition to changing the color subcarrier frequency. It was developed by JVC in the 1980s for use with their video disc players, hence the early name of "Disk-PAL". There is a little-used variation, also called PAL 60, which is a PAL video signal that uses the NTSC color subcarrier frequency (about 3.58 MHz), and PAL-type color modulation. 
palette  A central location for user-selectable buttons, which you can map to various functions for ease of use. The Command palette houses all the user-selectable buttons that allow you to perform a wide range of commands with a single click of the mouse. 
PALplus A widescreen (16x9) television standard in use in Europe that is compatible with existing 4x3 TV sets. Non-16x9 TVs show the picture in a letterboxed form.
pan 1. To move an image horizontally or vertically in the image window.
partition A subdivisioin of the total capacity of a storage disk that creates two or more virtual disks from a single physical disk. In the case of disk arrays, a partition is a virtual array within the whole array.
patching  The routing of audio or video from one channel or track in the sequence to another. 
path name A description of a file, program, or directory location on a hard disk drive that incorporates the names of directories and subdirectories.
PCI slot Connection slot to a type of expansion bus found in most newer personal computers. Most video capture cards require this type of connection. 
PDC See program delivery control. 
Pedestal Pedestal is an offset used to separate the black level from the blanking level by a small amount. When a video system doesn't use a pedestal, the black and blanking levels are the same. (M) NTSC uses a pedestal, (B, D, G, H, I) PAL does not. (M) NTSC-J used in Japan also does not use a pedestal. 
perforations Regularly spaced and accurately shaped holes which are punched throughout the length of a motion picture film. These holes engage the teeth of various sprockets and pins by which the film is advanced and positioned as it travels through cameras, processing machines, and projectors.
period The time elapsed during one complete cycle of a wave. 
petabyte 1000 Terabytes, or 1 million Gigabytes. You don't need it yet, but isn't it nice to know they've thought up a name for it? 
phase (1) A stage in a cycle. (2) The relationship between two periodic signals or processes. (3) The amount the cycles of one wave precede or follow the cycles of another wave of the same frequency. (4) A fraction of a wave cycle measured from a fixed point on the wave. 
Phase Adjust This is a term used to describe a method of adjusting the hue in a NTSC video signal. The phase of the color subcarrier is moved, or adjusted, relative to the color burst. PAL and SECAM systems do not usually have a phase (or hue) adjust control. 
Phase Alternating Line, (PAL) Colour television system developed in Germany and in use in most of Europe and China, Malaysia, Australia, New Zealand, the Middle East and parts of Africa. PAL-M is a Brazilian colour broadcasting system. Consists of 625 horizontal lines at a field rate of 50 fields (25 frames) per second. (Two fields equals one complete frame at 312.5 lines each). Only 576 of these lines are used for picture. The rest are used for sync or extra information such as VITC and Closed Captioning. 
pitch 1. That property of sound which is determined by the frequency of the sound waves. 2. Distance from the center of one perforation on a film to the next; or from one thread of a screw to the next; or from one curve of a spiral to the next.
pixel Short for Picture Element. The basic unit from which a video or computer picture is made. Essentially a dot with a given color and brightness value. D1 images are 720 pixels wide by 486 high. NTSC images are 640 by 480 pixels. As a picture element or picture cell
Pixel Clock The pixel clock is used to divide the horizontal line of video into samples. The pixel clock has to be stable (a very small amount of jitter) relative to the video or the image will not be stored correctly. The higher the frequency of the pixel clock, the more samples per line there are. 
Pixel Drop Out This can be a real troublemaker, since it can cause artifacts. In some instances, a pixel drop out looks like black spots on the screen, either stationary or moving around. Several things can cause pixel drop out, such as the ADC not digitizing the video correctly. Also, the timing between the ADC and the frame buffer might not be correct, causing the wrong number to be stored in memory. For that matter, the timing anywhere in the video stream might cause a pixel drop out. 
pixel square A pixel having equal width and height. Graphics programs normally create images with square pixels. NTSC and PAL video pixels, however, are generally rectangular. This means that graphics displayed on a TV screen will be distorted (for example, a circle will display as an elipse), unless the pixel aspect ratio of the graphics is adjusted to suit video.
plug-in A software module that can extend the features of and can be used within a software application. In Adobe Photoshop, for example, you can use various plug-ins for applying special effects to an image. 
point of interest The portion or area of a scene on which the camera focuses.
points  The mark IN and mark OUT entered in the Timeline. 
pop-up monitor  An ancillary monitor used to view and mark clips and sequences. 
position bar  The horizontal rectangular area beneath the Source monitor, Record monitor, Playback monitor, Composer monitor, and Source pop-up monitor that contains the position indicator. 
position indicator  A vertical blue line that moves in the position bar and in the Timeline to indicate the location of the frame displayed in the monitor. 
post-production The stage of a film or video project during which footage is edited and assembled and effects, graphics, titles, and sound are added. 
posterization An effect that reduces the various luminance levels of an image so that it looks flat or two-dimensional, somewhat like a poster or paint-by-number picture.
postroll  A preset period of time during a preview when a clip will continue to play past the OUT point before stopping or rewinding. 
pre-production The planning phase of a film or video project, usually completed prior to production. 
precomputed media  A computed effect stored in a file and referenced by a composition or sequence. Applications can precompute effects that they cannot create during playback. 
prelay  The phase of audio postproduction during which music, sound effects, dialog replacement, and announce tracks are added to the master multitrack before the final mix. 
preroll  The process of rewinding videotapes to a predetermined cue point (for example, 6 seconds) so the tapes are stabilized and up to speed when they reach the selected edit point (during recording or digitizing of source material from a video deck). 
preview  To rehearse an edit without actually performing (recording) it. 
preview code  An additional reference numbering system, like key numbers, supported by Film Composer for comparing digital sequences with evolving work print versions using change lists. 
primary color correction  Color correction that applies to every part of a video image, or to every part of a video image that falls within a defined luminance range. See also secondary color correction. 
Primary Colors A set of colors that can be combined to produce any desired set of intermediate colors, within a limitation call the "gamut". The primary colors for color television are red, green, and blue. The exact red, green, and blue colors used are dependent on the television standard. 
print  A positive copy of the film negative produced in the laboratory. See also answer print, release print, work print. 
Print to Video A feature of Adobe Premiere that enables you to play a clip or the Timeline centered on a monitor. If the clip or Timeline is smaller than the full screen, it will play alone or on a black background. Print to Video is useful for previewing the program in the Timeline, for viewing source clips or individual files, or for video playback because it allows you to play a quarter screen video at full screen size. Some capture cards do not support Print to Video. 
printing to tape Outputting a digital video file for recording onto a videotape. 
proc amp An electronic device that adjusts the differenct aspects of a video signal, such as its hue, saturation, and contrast.
process shot  A shot photographed specifically to be part of a special effects composite. 
processing amplifier An analog circuit that allows the luminance and chrominance parameters in a video camera to be controlled.
production The phase of a film or video project that involves shooting or recording raw footage. 
Program Delivery Control Information sent during the vertical blanking interval using teletext to control VCRs in Europe. The specification is ETSI ETS 300 231. 
program monitor The window in the Adobe Premiere interface that displays the edited program. 
Program side  In color correction, the second of two available levels of color adjustment. Corrections made on the Program side typically apply a final look to a finished sequence, for example, by fine-tuning the color values to enhance the mood of a dramatic program. See also Source side. 
progressive media  Media composed of single frames, each of which is vertically scanned as one pass. 
progressive scan, (Sequential Scanning) A scanning system for video screens where each line is displayed progressively (1,2,3,4...) as opposed to interlaced (1,3,5...2,4,6...). Computer monitors use progressive scan Unlike interlace scanning, the field and frame rate are identical in a progressive scanning system.. Some of the new HDTV standards call for progressive scan. 
project  A data device used to organize the work done on a program or series of programs. Bins, rundowns, and settings are organized in the Project window. The project bins contain all your clips, sequences, effects, and media file pointers. 
project preset A predetermined list of settings for a project. Certified capture cards usually include presets that work with Adobe Premiere. 
project settings All the items needed for Adobe Premiere to work properly with video and audio clips. 
Protection master  A copy (dub) of a master tape, usually made immediately after the master has been recorded. It is used as a backup if the master is damaged. 
protective master A master positive from which a dupe negative can be made if the original is damaged.
proxy A scaled-down version of an image used to display clips. It includes controls that mimic a VTR.
Pseudo Color Pseudo color is a term used to describe a technique that applies color, or shows color, where it does not really exist. We are all familiar with the satellite photos that show temperature differences across a continent or the multicolored cloud motion sequences on the nightly weather report. These are real-world examples of pseudo color. The color does not really exist. A computer uses a lookup table memory to add the color so information, such as temperature or cloud height, is viewable. 
pull-down The telecine transfer relationship of film frames to video fields. Film shot at 24 fps is transferred to 30 fps NTSC video with an alternating two-field/three-field relationship.
pulldown phase  In a project based on an NTSC 24-fps to 30-fps transfer, the video frame at which a master clip starts: A, B, X, C, or D. The pulldown phase represents the pulldown-to-timecode relationship. Also called pullin frame. 
pullin  An Avid term that combines two words — pulldown and IN point. The pullin is the column where the user logs the pulldown phase of the start timecode as either A, B, X, C, or D. The user can modify this field before or after digitizing or recording. 
pullout  An Avid term that combines two words — pulldown and OUT point. The pullout is the column where the user logs the pulldown relationship at the sync point of the OUT point (end timecode) as either A, B, C, or D. This field cannot be modified by the user and is calculated by the system based on the pullin and the duration of the clip.
pulse A current or voltage that abruptly alternates between two values within a given length of time. This term describes one variation in a series of wave motions. 
pulse distribution amplifier An amplifier that boosts sync strength and other control signals to the correct level required for distribution to multiple cameras, special effects generators, or other equipment. 
Px64 This is basically the same as H.261. The term is starting to fade away since H.261 is used in applications other than ISDN video conferencing. 
QAM See quadrature amplitude modulation. 
QCIF Quarter Common Interface Format. This video format was developed to allow the implementation of cheaper video phones. The QCIF format has a resolution of 176 x 144 active pixels and a refresh rate of 29.97 frames per second. 
QSIF Quarter Standard Interface Format. The computer industry, which uses square pixels, has defined QSIF to be 160 x 120 active pixels, with a refresh rate of whatever the computer is capable of supporting. 
Quad Chroma Quad chroma refers to a technique where the sample clock is four times the frequency of the color burst. For NTSC this means that the sample clock is about 14.32 MHz (4 x 3.579545 MHz), while for PAL the sample clock is about 17.73 MHz (4 x 4.43361875 MHz). The reason these are popular sample clock frequencies is that, depending on the method chosen, they make the chrominance (color) decoding and encoding easier. 
Quadrature Amplitude Modulation A method of encoding digital data onto a carrier for RF transmission. QAM is typically used for cable transmission of digital SDTV and HDTV signals. DVB-C supports 16-QAM, 32-QAM, 64-QAM, 128-QAM, and 256-QAM, although receivers need only support up to 64-QAM. 
Quadrature Modulation The modulation of two carrier components, which are 90 degrees apart in phase. 
Quantization The process of converting a continuous analog signal into a set of discrete levels (digitizing). 
Quantization Noise This is the inherent uncertainty introduced during quantization since only discrete, rather than continuous, levels are generated. Also called quantization distortion. 
QuickTime Apple Computer's multi-platform, industry-standard, multimedia software architecture. QuickTime is used by software developers, hardware manufacturers, and content creators to author and publish synchronized graphics, sound, video, text, music, virtual reality, and 3-D media. QuickTime 4 includes support for Real Time Streaming Protocol (RTSP). 
R'-Y' In video, the red-minus-luma signal, also called a color difference signal. When added to the luma (Y') signal, it produces the red video signal. 
rack A frame carrying film in a processing machine.
Radio Frequency output, (RF output) An RF output on a video recorder allows picture and sound to be played over a vacant channel in a conventional TV receiver. 
radio frequency (RF) Any of the electromagnetic wave frequencies within the range that extends from below 3 kHz to approximately 300 GHz, and include the frequencies used for radio and television transmissions. For television transmissions, a composite video signal is superimposed onto a very high radio frequency capable of being broadcast through the atmosphere. Standard televisions receive these video signals, separate the composite signal from the radio frequency, and then decode and display the composite signal.
radio frequency (RF)  The high-frequency portion of the electromagnetic spectrum used for transmitting television and radio signals. See also UHF, VHF. 
RAID  Redundant Array of Independent Disks. The storage device standards that provide fault tolerance, which helps to recover a system if a drive malfunctions. RAID is also used to enhance throughput of stored data. 
RAM Acronym for random access memory, the computer memory that provides temporary internal storage for working with applications and manipulating data.
random access  The ability to move to a video point instantly, without having to shuttle. 
Raster Essentially, a raster is the series of scan lines that make up a picture. You may from time to time hear the term raster line -- it's the same as scan line. All of the scan lines that make up a frame of video form a raster. 
raw footage Original, unedited film or video footage that has not been modified.
Raw VBI Data A technique where VBI data (such as teletext and captioning data) is sampled by a fast sample clock (i.e. 27 MHz), and output. This technique allows software decoding of the VBI data to be done. 
RC Time Code Rewritable time code, used in consumer video products. 
real-time In computing, an operating mode under which data is received, processed, and the results returned quickly enough to seem instantaneous. In video, real-time also refers to effects and transitions that happen without interrupting rendering.
Real-Time Control Protocol See RTCP. 
Real-Time Streaming Protocol See RTSP. 
Real-Time Transport Protocol See RTP. 
RealMedia Architecture designed specifically for the Web, featuring multimedia streaming and low data-rate compression options. RealMedia works with or without a RealMedia server.
record  To convert analog video and audio signals to an Avid compressed digital signal format. 
Rectangular Pixels Pixels that are not "square pixels" are "rectangular pixels". 
Red, Green, Blue, (RGB) The primary colors of light. The primary colour components of the additive colour system used in colour television. An industry colour standard used to describe colour components or colour space. Computers and some analog component devices use separate red, green, and blue color channels to keep the full bandwidth and therefore the highest quality picture.
reduction printing Making a copy of smaller size than the original by optical printing.
reel  A spool with a center hub and flat sides on which magnetic tape is wound. Generally, a spool of tape is referred to as a reel, and a spool of film is referred to as a roll. 
region of interest  The part of an image that the user identifies as the target for a motion tracking operation. Also called the search pattern. 
registration (1) The adjustment that ensures all three electron beams of a color monitor and projector—red, green, and blue—hit the proper color dots/stripes on the phosphor screen. (2) The frame-by-frame alignment of film in a camera or projector.
rehearse  To play a sequence in the Timeline from the preroll through the postroll. 
rehearse postroll  To play a sequence in the Timeline from the current position to the postroll. 
rehearse preroll  To play a sequence in the Timeline from the preroll to the current position. 
release print In a motion picture processing laboratory, any of numerous duplicate prints of a subject made for general theatre distribution.
rendering The transformation of the abstract description of 3D objects into 2D pixel information.
repeat effect  "A type of effect for repeating a frame so that it appears to ""freeze"" or stop the frame, or for repeating a series of frames, such as a series of animation frames. "
replace edit  An edit in which a segment in the sequence is overwritten or replaced with source material of matching duration. 
Residual Subcarrier This is the amount of color subcarrier information present in white, gray, or black areas of a composite color video signal (ideally, there is none present). The number usually appears as -n dB. The larger "n" is, the better. 
Resolution This is the basic measurement of how much information is visible for an image. It is usually described as "h" x "v". The "h" is the horizontal resolution (across the display) and the "v" is the vertical resolution (down the display). The higher the numbers, the better, since that means there is more detail to see. If only one number is specified, it is the horizontal resolution. Displays specify the maximum resolution they can handle, determined by the display technology and the electronics used. The actual resolution will be the resolution of either the source or the display, whichever is lower. Vertical resolution is the number of white-to-black and black-to-white transitions that can be seen from the top to the bottom of the picture. The maximum number is the number of active scan lines used by the image. The actual vertical resolution may be less due to processing, interlacing, overscanning, or limited by the source. Horizontal resolution is the number of white-to-black and black-to-white transitions that can be seen from the left to the right of the picture. For digital displays, the maximum number is the number of active pixels used by a scan line. For both analog and digital displays, the actual horizontal resolution may be less due to processing, overscanning, or limited by the source. 
resolution independent A term to describe equipment that can work in more than resolution. Most equipment can do film resolution or video resolution, but not both. Resolution independent equipment can work in both.
reticulation The formation of a coarse, crackled surface on the emulsion coating of a film during improper processing. If some process solution is too hot or too alkaline, it may cause excessive swelling of the emulsion and this swollen gelatin may fail to dry down as a smooth homogeneous layer.
Retrace Retrace is what the electron beam does when it gets to the right-hand edge of the CRT display to get back to the left-hand edge. Retrace happens during the horizontal blanking time. 
reversal process Any photographic process in which an image is produced by secondary development of the silver halide grains that remain after the latent image has been changed to silver by primary development and destroyed by a chemical bleach. In the case of film exposed in a camera, the first developer changes the latent image to a negative silver image. This is destroyed by a bleach and the remaining silver halide is converted to a positive image by a second developer. The bleached silver and any traces of halide may now be removed with hypo.
reverse A command used to reverse the order of frames in a clip.
RF  See radio frequency (RF). 
RGB Abbreviation for red, green, blue; the three primary colors of the additive color system, such as that used to display color on a computer monitor or television screen. 
RGB video A component video signalthat uses three signals to carry the separate Red, Green, and Blue channels of coloured images.
RIFF wave  See WAVE. 
ripple Automatic updating of an EDL after a length-altering edit. "Ripple the list". A setting that determines how the overall length of the edit sequence is affected when a clip is inserted. When ripple is on, the timecode and frame count increase or decrease (ripple) to accommodate the added or removed material.
rise time The amount of time is takes for a signal to transition from one state to another. Rise time is usually measured between the 10% and 90% completion points of the transition. Shorter, or faster rise times require more bandwidth in a transmission channel.
RMAG  "Removable magnetic disk. RMAGs are used in conjunction with chassis; each chassis can hold two of these removable disk modules. "
roll 1. Vertical movement of text across the screen. 2. Unwanted vertical roll of a video image, indicating unstable sync.
rolling text  Text that moves vertically across an area over time. The most common example of rolling text is credits at the end of feature films and television programs. 
rotoscope The procedure to remove an object from a shot, such as the wires that make an actor appear to fly.
rough cut  A preliminary edit of a program, usually the result of an offline edit. See also work print. 
RS-170, RS-170A RS-170 is the United States standard that was used for black-and-white TV, and defines voltage levels, blanking times, the width of the sync pulses, and so forth. The specification spells out everything required for a receiver to display a monochrome picture. Now, SMPTE 170M is essentially the same specification, modified for color TV by adding the color components. They modified RS-170 just a tiny little bit so that color could be added (RS-170A), with the final result being SMPTE 170M for NTSC. This tiny little change was so small that the existing black-and-white TVs didn't even notice it. 
RS-232 A standard for serial communication used by most computer and several video platforms.
RS-232C  The Electronic Industries Association standard interface for connecting serial devices. Usually referred to by the original standard name of RS-232. The standard supports two types of connectors: a 25-pin D-type connector and a 9-pin D-type connector. The maximum permissible line length under the specification is approximately 15 meters. 
RS-343 RS-343 does the same thing as RS-170, defining a specification for transferring analog video, but the difference is that RS-343 is for high-resolution computer graphics analog video, while RS-170 is for TV-resolution NTSC analog video. 
RS-422  The Electronic Industries Association standard interface for connecting serial devices. The RS-422 is an enhancement of the RS-232C standard. It allows for higher data rates and an extended line length to approximately 1200 meters. 
RSDL RSDL stands for Reverse Spiral Dual Layer. It is a storage method that uses two layers of information on one side of a DVD. For movies that are longer than can be recorded on one layer, the disc stops spinning, reverses direction, and begins playing from the next layer. 
RSVP RSVP (Resource Reservation Protocol) is a control protocol that allows a receiver to request a specific quality of service level over an IP network. Real-time applications, such as streaming video, use RSVP to reserve necessary resources at routers along the transmission paths so that the requested bandwidth can be available when the transmission actually occurs. 
RTCP RTCP (Real-Time Control Protocol) is a control protocol designed to work in conjunction with RTP. During a RTP session, participants periodically send RTCP packets to convey status on quality of service and membership management. RTCP also uses RSVP to reserve resources to guarantee a given quality of service. 
RTP RTP (Real-Time Transport Protocol) is a packet format and protocol for the transport of real-time audio and video data over an IP network. The data may be any file format, including MPEG-2, MPEG-4, ASF, QuickTime, etc. Implementing time reconstruction, loss detection, security and content identification, it also supports multicasting (one source to many receivers) and unicasting (one source to one receiver) of real-time audio and video. One-way transport (such as video-on-demand) as well as interactive services (such as Internet telephony) are supported. RTP is designed to work in conjunction with RTCP. 
RTSP RTSP (Real-Time Streaming Protocol) is a client-server protocol to enable controlled delivery of streaming audio and video over an IP network. It provides "VCR-style" remote control capabilities such as play, pause, fast forward, and reverse. The actual data delivery is done using RTP. 
Run Length Coding Run length coding is a type of data compression. Let's say that this page is wide enough to hold a line of 80 characters. Now, imagine a line that is almost blank except for a few words. It's 80 characters long, but it's just about all blanks -- let's say 50 blanks between the words "coding" and "medium". These 50 blanks could be stored as 50 individual codes, but that would take up 50 bytes of storage. An alternative would be to define a special code that said a string of blanks is coming and the next number is the amount of blanks in the string. So, using our example, we would need only 2 bytes to store the string of 50 blanks, the first special code byte followed by the number 50. We compressed the data; 50 bytes down to 2. This is a compression ration of 25:1. Not bad, except that we only compressed one line out of the entire document, so we should expect that the total compression ratio would be much less. Run length coding all by itself as applied to images is not as efficient as using a DCT for compression, since long runs of the same "number" rarely exist in real-world images. The only advantage of run length coding over the DCT is that it is easier to implement. Even though run length coding by itself is not efficient for compressing images, it is still used as part of the JPEG, MPEG, H.261, and H.263 compression schemes. 
rushes  See dailies. 
S-VHS S-VHS is an enhancement to regular VHS video tape decks. S-VHS provides better resolution and less noise than VHS. S-VHS video tape decks support s-video inputs and outputs, although this is not required. It does, however, improve the quality by not having to separate and then merge the luma and chroma signals. 
S-Video Separate video, also called Y/C video. Separate luma (Y') and chroma (C) video signals are used, rather than a single composite video signal. By simply adding together the Y' and C signals, you generate a composite video signal. A DC offset of +2.3v may be present on the C signal when a letterbox picture format is present. A DC offset of +5v may be present to indicate when a 16:9 anamorphic picture format is present. A standard 4:3 receiver ignores all DC offsets, thus displaying a typical letterboxed picture. 
SABC South Africa Broadcasting Corporation. 
safe action area, safe title area  The regions of the video image considered safe from cropping for either the action or on-screen titles, taking into account variations in adjustments for video monitors or television receivers. Safe action is 90 percent of the screen measured from the center, and safe title is 80 percent. 
safe color limiting  The process of adjusting color values in a finished program so that they meet broadcast standards for luminance, composite signal, or RGB gamut. 
safe title area The area that comprises the 80 percent of the TV screen measured from the center of the screen outward in all directions. The safe title area is the area within which title credits—no matter how poorly adjusted a monitor or receiver may be—are legible.
safety film A photographic film whose base is fire-resistant or slow burning. At the present time, the terms "safety film" and "acetate film" are synonymous.
Sample To obtain values of a signal at periodic intervals. Also the value of a signal at a given moment in time. 
Sample and Hold A circuit that samples a signal and holds the value until the next sample is taken. 
sample data  The media data created by recording or digitizing from a physical source. A sample is a unit of data that the recording or digitizing device can measure. Applications can play digital sample data from files on disk. 
sample plot  The representation of audio as a sample waveform. 
Sample Rate Sample rate is how often a sample of a signal is taken. The sample rate is determined by the sample clock. 
sample unit  A unit of measure used in recording or digitizing media data from a physical source, such as a videotape. Media data contains its own sample rate and the size of each sample in bytes. 
sampling  "The process of measuring the value of an analog signal at regular intervals during recording or digitizing. These measurements (""samples"") are used to construct a digital representation of the signal. "
sampling frequency The number of sample measurements taken from an analog signal in a given period of time. These samples are then converted into numerical values stored in bytes to create the digital signal. 
satellite mode  Recording using LTC timecode of live events, multicamera shows, and video material coming in on routers. Allows you to record to the NewsCutter system from multiple external sources at the same time they are recording to tape. 
saturation The strength or purity of a color. Saturation represents the amount of gray in proportion to the hue, measured as a percentage from 0% (gray) to 100% (fully saturated). The color information of a video signal comprises hue (phase angle) and saturation (amplitude). 
SC phase  Subcarrier phase. The method used to calibrate the colorburst portion of a composite video signal. 
SC/H phase  Subcarrier to horizontal phase. The phase relationship between the burst and the horizontal blanking reference point for a video signal. Used to synchronize the timing of two or more video signals. 
scale bar  A control in the Timeline window that allows you to expand and contract the Timeline area centered around the blue position indicator. 
Scaling Scaling is the act of changing the resolution of an image. For example, scaling a 640 x 480 image by one-half results in a 320 x 240 image. Scaling by 2x results in an image that is 1280 x 960. There are many different methods for image scaling, and some "look" better than others. In general, though, the better the algorithm "looks", the more expensive it is to implement. 
scan converter A device that changes the scan rate of a video signal and may also convert the signal from noninterlaced to interlaced mode. A scan converter enables computer graphics to be recorded onto videotape or displayed on a standard video monitor.
Scan Line A scan line is an individual line across the display. It takes 525 of these scan lines to make up a NTSC TV picture and 625 scan lines to make up a PAL TV picture. 
scan rate The length of time an electron gun takes to move across one line of the screen (horizontal scan rate), or to repeat one entire screen (vertical scan rate). Computer monitor scan rates differ from those of standard video display devices.
Scan Velocity Modulation See velocity scan modulation. 
scanning The movement of the election beam in the CRT of a television receiver or in the pickup device of a camera. The electron beam moves line-by-line across the photo sensitive surface, producing the video picture.
SCART Syndicat des Constructeurs d'Appareils Radio Recepteurs et Televiseurs. This is a 21-pin connector supported by many consumer video components in Europe. It allows mono or stereo audio and composite, s-video, or RGB video to be transmitted between equipment. 
scene An image window view in DVE in which you can see and manipulate objects, axes, lights and the camera.
schematic view An illustration in DVE that depicts the different relationships between objects and layers.
Scratch Disks The user-defined hard disk location where an application stores temporary and preview files.
screening  A showing of a film program, video program, or raw footage. 
scroll The vertical motion of text or images on a video screen.
scroll bar  A rectangular bar located along the right side or the bottom of a window. Clicking or dragging in the scroll bar allows the user to move or pan through the file. 
scrubbing The backward or forward movement through audio or video material via a mouse, keyboard, or other device.
SDTI Serial Data Transport Interface, defined by SMPTE 305M. 
search pattern  See region of interest. 
SECAM  Séquential Couleur à Memoire. A color television standard developed in France and used throughout Europe. See also NTSC, PAL. 
Secondary Audio Program, (SAP) Generally used to transmit audio in a second language. 
secondary color correction  Color correction that applies to specific parts of an image defined by hue and saturation values. A secondary color correction can change the green parts of an image to yellow without altering other colors in the image. See also primary color correction. 
SEG  Special effects generator. A section of a switcher that provides the capability to perform wipes of various patterns. 
segment  A section of a track or clip within a sequence in the Timeline that can be edited. 
self-key A key effect in which the key source image is also the foreground image.
sensitometer An instrument with which a photographic emulsion is given a graduated series of exposures to light of controlled spectral quality, intensity, and duration. Depending upon whether the exposures vary in brightness or duration, the instrument may be called an intensity scale or a time scale sensitometer.
sequence  An edited composition that often includes audio and video clips and rendered effects connected by applied transitions. The Avid system contains a Timeline that graphically represents the edited sequence. 
Sequential Colour And Memory, (SECAM) A broadcast standard used in Eastern Europe, France and parts of Africa that is partially compatible with the PAL standard but incompatible with NTSC, specifically, colour signals are encoded differently from PAL. The SECAM standard uses a 625-line, 50 cycle power source, 25-frame-per-second signal.The major differences between the two are that in SECAM the chroma is FM modulated and the R'-Y' and B'-Y' signals are transmitted line sequentially. SECAM stands for Sequentiel Couleur Avec Memoire or Sequential Color with Memory. 
serial control A method of remotely controlling a device via a data line. The control data is transmitted in serial form (that is, one bit after another).
serial device control Most professional video equipment can be controlled via an RS-232 or RS-422 serial port. The protocols used for controlling these devices varies from vendor to vendor, however, Sony's protocol is supported by most editing systems.
Serial Digital Interface, (SDI) Serial Digital I/O. Another name for the 270 Mbps or 360 Mbps serial interface defined by BT.656. It is used primarily on professional and studio video equipment. 
serial timecode  See LTC. 
Serration Pulses These are pulses that occur during the vertical sync interval of NTSC, PAL, and SECAM, at twice the normal horizontal scan rate. The reason these exist was to ensure correct 2:1 interlacing in early televisions and eliminate DC offset buildup. 
setup  A reference point in the video signal that is the blackest point in the visible picture. See also black level or pedestal. See also waveform. 
setup files Customized menus, filters, settings, etc., that you create and can save in UNIX to reuse during work sessions.
shadows Dark areas in an image.
shared volume segmentation  See chunking. 
shelf  "The effect produced by a shelving equalizer in which the response curve for a certain range of the frequency spectrum (high or low frequency, for example) flattens out or ""shelves"" at the limits of the audio spectrum. In audio equalization, adjustments to the shelf affect all frequencies within the range of the response curve. "
shot A sequence of images and/or clips.
shot log  A listing of information about a roll of film or a reel of videotape, usually in chronological order. 
shuttling  The viewing of footage at speeds greater than real time. 
SI  Système International d'Unites. The French version of the International System of Units. SI is roughly equivalent to the metric system. 
SIF Standard (or Source) Input Format. This video format was developed to allow the storage and transmission of digital video. The 625/50 SIF format has a resolution of 352 x 288 active pixels and a refresh rate of 25 frames per second. The 525/60 SIF format has a resolution of 352 x 240 active pixels and a refresh rate of 30 frames per second. Note that MPEG-1 allows resolutions up to 4095 x 4095 active pixels; however, there is a "constrained subset" of parameters defined as SIF. The computer industry, which uses square pixels, has defined SIF to be 320 x 240 active pixels, with a refresh rate of whatever the computer is capable of supporting. 
sifting  The displaying of clips that meet specific criteria in a bin. 
signal-to-noise ratio  The ratio of a wanted signal to an unwanted signal. 
signal-to-noise ratio (S/N) (SNR) Expressed in decibels (dB), the ratio of noise as compared to the total signal strength of the luminance, chrominance, and audio signals. The higher the value, the clearer the picture and sound during playback.
silence  Blank (black) space in the audio tracks in a Timeline that contains no audio material. 
Silent Radio Silent Radio is a service that feeds data that is often seen in hotels and nightclubs. It's usually a large red sign that shows current news, events, scores, etc. It is present on NTSC lines 10- 11 and 273-274, and uses encoding similar to EIA-608. 
single-line display.  See also vectorscope. 2. In audio, a visual representation of changing frequencies. See also energy plot, sample plot. 
single-perf film  Film stock that is perforated along one edge only. 
single-strand editing  See A-roll. 
skip frame An optical printing effect eliminating selected frames of the original scene to speed up the action.
slate  An identification board held briefly in front of the camera at the beginning of a take that displays information about the take. A smart slate also includes a timecode display that is fed from the sound recorder for synchronization purposes. 
slewing  The synchronizing of decks in computerized editing systems. 
Sliced VBI Data A technique where a VBI decoder samples the VBI data (such as teletext and captioning data), locks to the timing information, and converts it to binary 0's and 1's. DC offsets, amplitude variations, and ghosting must be compensated for by the VBI decoder to accurately recover the data. 
slide A editing feature that adjusts the Out point of the previous clip, and the In point of the next clip without affecting the clip being slid or the program duration.
slide trimming  The outgoing (A-side) and incoming (B-side) frames change because the clip remains fixed while the footage before and after it is trimmed. 
slip An editing feature that adjusts the In and Out points of a clip without affecting the adjacent clips or program duration. 
slip trimming  The head and tail frames of the clip change because only the contents of the clip are adjusted. The frames that precede and follow the clip are not affected. 
Small Computer System Interface, (SCSI) A standard connection for computers, disk drives and peripheral devices.
smart slate  See slate. 
SMPTE  Society of Motion Picture and Television Engineers. One of the principal standards organizations for the film and video industry. See also SMPTE timecode, timecode. 
SMPTE 125M 720 x 480 pro-video interlaced standard (29.97 Hz). Covers the digital representation and the digital parallel interface. Also see BT.601 and BT.656. 
SMPTE 12M Defines the longitudinal (LTC) and vertical interval (VITC) timecode for NTSC and PAL video systems. LTC requires an entire field time to store timecode information, using a separate track. VITC uses one scan line each field during the vertical blanking interval. 
SMPTE 170M NTSC video specification for the United States. See RS-170A and BT.470. 
SMPTE 240M 1920 x 1035 pro-video interlaced standard (29.97 or 30 Hz). Covers the analog RGB and YPbPr representation. The digital parallel interface is defined by SMPTE 260M. The digital serial interface is defined by SMPTE 292M. 
SMPTE 244M 768 x 486 pro-video interlaced standard (29.97 Hz). Covers the digital representation (composite NTSC video sampled at 4x Fsc) and the digital parallel interface. The digital serial interface is defined by SMPTE 259M. 
SMPTE 253M Analog RGB video interface specification for pro-video SDTV systems. 
SMPTE 259M Pro-video serial digital interface for SMPTE 244M. 
SMPTE 260M Digital representation and parallel interface for SMPTE 240M video. 
SMPTE 266M Defines the digital vertical interval timecode (DVITC). Also see BT.1366. 
SMPTE 267M 960 x 480 pro-video interlaced standard (29.97 Hz). Covers the digital representation and the digital parallel interface. Also see BT.601 and BT.1302. 
SMPTE 272M Formatting AES/EBU digital audio and auxiliary data into the digital blanking intervals. Also see BT.1305. 
SMPTE 274M 1920 x 1080 pro-video interlaced and progressive standards. Covers the digital representation, the analog RGB and YPbPr interfaces, and the digital parallel interface. The digital serial interface is defined by SMPTE 292M. 
SMPTE 276M Transmission of AES/EBU digital audio and auxiliary data over coaxial cable. 
SMPTE 291M Ancillary data packet and space formatting for pro-video digital interfaces. Also see BT.1364. 
SMPTE 292M 1.485 Gbps pro-video HDTV serial interfaces. 
SMPTE 293M 720 x 480 pro-video progressive standards (59.94 Hz). Covers the digital representation, the analog RGB and YPbPr interfaces, and the digital parallel interface. The digital serial interface is defined by SMPTE 294M. Also see BT.1358 and BT.1362. 
SMPTE 294M Pro-video serial digital interface for SMPTE 293M. 
SMPTE 296M 1280 x 720 pro-video progressive standards. Covers the digital representation and the analog RGB and YPbPr interfaces. The digital parallel interface uses SMPTE 274M. The digital serial interface is defined by SMPTE 292M. 
SMPTE 299M 24-bit digital audio format for pro-video HDTV serial interfaces. Also see BT.1365. 
SMPTE 305M Serial data transport interface (SDTI). This is a 270 or 360 Mbps serial interface based on BT.656 that can be used to transfer almost any type of digital data, including MPEG-2 program streams, MPEG-2 transport streams, DV bit streams, etc. You cannot exchange material between devices that use different data types. Material that is created in one data type can only be transported to other devices that support the same data type. There are separate map documents that format each data type into the 305M transport. 
SMPTE 308M MPEG-2 4:2:2 profile at high level. 
SMPTE 314M Data structure for DV-based audio, data and compressed video at 25 and 50 Mbps. Also see IEC 61834. 
SMPTE 322M Data stream format for the exchange of DV-based audio, data and compressed video over a Serial Data Transport Interface (SDTI or SMPTE 305M). 
SMPTE 344M Defines a 540 Mbps serial digital interface for pro-video applications. 
SMPTE 348M High data-rate serial data transport interface (HD-SDTI). This is a 1.485 Gbps serial interface based on SMPTE 292M that can be used to transfer almost any type of digital data, including MPEG-2 program streams, MPEG-2 transport streams, DV bit streams, etc. You cannot exchange material between devices that use different data types. Material that is created in one data type can only be transported to other devices that support the same data type. There are separate map documents that format each data type into the 348M transport. 
SMPTE format (SMPTE standard) In component video, the SMPTE format or SMPTE standard refers to the standards for parallel analog component video interconnection.
SMPTE RP160 Analog RGB and YPbPr video interface specification for pro-video HDTV systems. 
SMPTE timecode  "A frame-numbering system developed by the Society of Motion Picture and Television Engineers that is used primarily for electronic editing and timing of video programs. It assigns a number to each frame of video, telling the elapsed number of hours, minutes, seconds, and frames; for example, 01:42:13:26. See also time-of-day timecode. "
snow (1) Random noise on a display screen often the result of dirty videotape heads. (2) TV signal breakup caused by poor reception.
SNR, (Signal to Noise Ratio) The ratio in decibels of the maximum peak-to-peak voltage of the TV signal (sometimes including sync) to the voltage of the noise at any point. The higher the ratio, the better. 
Society of Motion Picture and TV Engineers, (SMPTE) An industry organisation which sets standards and specifications in the film and TV industries.
soft The opposite of "hard". 1. As applied to a photographic emulsion or developer, having a low contrast. 2. As applied to the lighting of a set, diffuse, giving a flat scene in which the brightness difference between highlights and shadows is small.
soft edit An electronic edit that maintains source clips in memory and tracking processes so that edits can be modified without starting from scratch.
soft key A key effect that has a fuzzy, soft edge or semi-transparent areas.
soft wipe A split screen or wipe effect with a soft border or edge where the two images join.
softness A blending or mixing along lines or edges in an image.
software effect An effect that must be rendered by an editing application before it can be played back. Contrast with real-time. 
sorting  The arranging of clips in a bin column in numerical or alphabetical order, depending on the column the user selects. 
Sound Designer II  A trademark of Avid Technology, Inc. An audio file format used for the import and export of digital audio tracks. 
sound digitizer A device that records sounds and stores them as computer files.
source clip  One of the lowest level building blocks of a sequence composition. See also clip, master clip, subclip. 
source mode  A method of assembly that determines in what order the edit controller reads the edit decision list (EDL) and assembles the final tape. There are five different types of source mode: A-mode, B-mode, C-mode, D-mode, and E-mode. 
source monitor The interface window of Adobe Premiere that displays clips to be edited. 
Source side  In color correction, the first of two available levels of color adjustment. Corrections made on the Source side typically seek to restore the original color characteristics of a clip or achieve basic clip-to-clip color consistency among the clips in a sequence. See also Program side. 
spatial compression A compression method that reduces the data contained within a single video frame by identifying areas of similar color and eliminating the redundancy. See also, codec. 
SPDIF Short for Sony/Philips Digital InterFace. This is a consumer interface used to transfer digital audio. A serial, self-clocking scheme is used, based on a coax or fiber interconnect. The audio samples may be 16-24 bits each. 16 different sampling rates are supported, with 32, 44.1, and 48 kHz being the most common. IEC 60958 now fully defines this interface for consumer and professional applications. 
specular  An intense highlight caused when light reflects off an object in an image. A specular is not used as the basis for determining the true white point for an image. 
speed  The point at which videotape playback reaches a stable speed, all servos are locked, and there is enough preroll time for editing, recording, or digitizing. 
splice  An edit in which the material already on the video or audio track is lengthened by the addition of new material spliced in at any point in the sequence. See also overwrite. 
spline A curved line.
split edit  See overlap edit. 
split screen A special effect that utilizes two or more video sources to enable two or more scenes to be simultaneously visible different parts of the screen. Split screen is often used for making window-dubs of multi-camera shoots, which is useful for comparing two sources simultaneously and quickly checking of the phase and sync timing between two inputs.
Split Sync Scrambling Split sync is a video scrambling technique, usually used with either horizontal blanking inversion, active video inversion, or both. In split sync, the horizontal sync pulse is "split", with the second half of the pulse at +100 IRE instead of the standard -40 IRE. Depending on the scrambling mode, either the entire horizontal blanking interval is inverted about the +30 IRE axis, the active video is inverted about the +30 IRE axis, both are inverted, or neither is inverted. By splitting the horizontal sync pulse, a reference of both -40 IRE and +100 IRE is available to the descrambler. Since a portion of the horizontal sync is still at -40 IRE, some sync separators may still lock on the shortened horizontal sync pulses. However, the timing circuits that look for color burst a fixed interval after the end of horizontal sync may be confused. In addition, if the active video is inverted, some video information may fall below 0 IRE, possibly confusing sync detector circuits. The burst is always present at the correct frequency and timing; however, the phase is shifted 180 degrees when the horizontal blanking interval is inverted. 
spot color correction  A color adjustment made to a specific part of a video image that is identified using drawing tools. See also secondary color correction. 
sprocket A toothed driving wheel used to move film through various machine by engaging with the perforation holes.
Square Pixels A "square pixel" is one that has the same number of active samples both horizontally and vertically, for a 1:1 aspect ratio. Computers and HDTV use square pixels. Using 480 active scan lines for NTSC, if the display had a 1:1 aspect ratio, square pixels would mean there would be 480 active samples per line. Since the display has a 4:3 aspect ratio, the number of active samples is (480)*(4/3) or 640. To get 640 active samples per line, you need a 12.27 MHz sample clock. Using 576 active scan lines for PAL, if the display had a 1:1 aspect ratio, square pixels would mean there would be 576 active samples per line. Since the display has a 4:3 aspect ratio, the number of active samples is (576)*(4/3) or 768. To get 768 active samples per line, you need a 14.75 MHz sample clock. 
stabilization  A specialized form of motion tracking used to eliminate unwanted motion such as camera movement from a clip. Stabilization works by tracking an inherently unmoving object in the clip and repositioning each frame or field of video to keep that object stationary. 
stabilize 1. Remove motion jitter and unwanted camera movement from a clip. 2. To track an image in a clip.
Standard Definition Television, (SDTV) Short for Standard Definition Television. SDTV is a television that displays less active vertical resolution than EDTV. No aspect ratio is specified. The new HDTV standards call for a range of different resolutions. Those that are higher than today's NTSC are considered HDTV. The ones that are comparable to NTSC are considered SDTV. Because SDTV is component and digital it will still be higher quality than NTSC. 
Starsight An electronic program guide that you subscribe to. It allows you to sort the guide by your order of preference and delete stations you never watch. It's a national service, that is regionalized. The decoders in Houston only download data for Houston. Move to Dallas and you only get Dallas. It is present on NTSC lines 14 and 277, and uses encoding similar to EIA-608. 
startup disk  The disk that contains the operating system files. The computer needs operating system information in order to run. 
steady gate A pin-registered device manufactured by Steady Film for precise telecine transfer. Provides more stables images than EPR, but does not operate in real time.
step printer A printer n which each frame of the negative and raw stock is stationary at the time of exposure.
stepping  The movement forward or backward one frame at a time. See also jogging. 
still frame A single frame of video repeated so it appears to have no motion.
still store Device which stores individual video frames, either in analog or digital form, allowing extremely fast access time.
story  The Avid term for an edited piece. A story is created by editing clips and sequences together. 
storyboard  A series of pictures (traditionally sketches) designed to show how a production will look. Comic books are essentially storyboards. Storyboards and subsequent sequences can be created by manipulating images from the recorded or digitized footage in a bin. 
streaming The process of sending video over the Web or other networks to allow playback on the desktop as the video is received, rather than requiring the entire file to be downloaded prior to playback.
Streaming Video Compressed audio and video that is transmitted over the Internet or other network in real time. Typical compression techniques are MPEG-2, MPEG-4, Microsoft WMT, RealNetworks, and Apple's QuickTime. It usually offers "VCR-style" remote control capabilities such as play, pause, fast forward, and reverse. 
strip Part of a wide roll of manufactured film slit to its final width for motion picture use.
stripe A narrow band of magnetic coating or developing solution applied to a length of motion picture film.
striped stock  1. Film stock to which a narrow stripe of magnetic recording material has been applied for the recording of a sound track. See black and code.
striping Preparing a tape for editing by recording continuous control track, timecode, and a video signal (e.g., black). Also known as black stripe. 
striping a tape Preparing a tape for editing by recording continuous control track, time code, and a video signal (such as black or colour bars). subcarrier
subcarrier A 3.58 MHz signal modulated by color signals and combined with luminance signals to produce an NTSC composite video signal. The subcarrier is the basic signal in all NTSC sync signals. All other synchronizing signals are divided directly from the subcarrier.
subcarrier phase shifter Special circuitry that controls the phase relationships of the two parts of the encoded color signal, ensuring the relationship is correct during recording, transmission, and reproduction.
subcarrier (SC)  The sine wave used as a color reference signal. 
subclip  1. An edited part of a clip. In a sequence, a subclip can be bound by any variation of clip beginnings, endings, and mark points.2. A subclip created by marking IN and OUT points in a clip and by saving the frames between the points. The subclip does not contain pointers to media files. The subclip references the master clip, which alone contains pointers to the media files.
Subsampled Subsampled means that a signal has been sampled at a lower rate than some other signal in the system. A prime example of this is the 4:2:2 Y'CbCr color space used in ITU-R BT.601. For every two luma (Y') samples, only one Cb and Cr sample is present. This means that the Cb and Cr signals are subsampled. 
Subtitles Text that is added below or over a picture that usually reflects what is being said, possibly in another language. Open subtitles are transmitted as video that already has the subtitles present. Closed subtitles are transmitted during the VBI, and relies on the TV to decode it and position it below or over the picture. Closed captioning is a form of subtitling. Subtitling for DVB is specified in ETSI ETS 300 743. 
Super 16  The 16mm film stock produced for a special format with an enlarged picture area. Super 16 is designed to be printed to 35mm film for release. 
Super Black A keying signal that is embedded within the composite video signal as a level between black and sync. It is usually used to improve luma self-keying because the video signal contains black, making a good luma self-key hard to implement. When a downstream keyer detects the super black level, it inserts the second composite video signal. 
Super VideoCD (Super VCD, SVCD) Next generation VideoCD, defined by the China National Technical Committee of Standards on Recording, that hold 35-70 minutes of digital audio and video information. MPEG-2 video is used, with a resolution of 480 x 480 (29.97 Hz frame rate) or 480 x 576 (25 Hz frame rate). Audio uses MPEG-1 layer 2 or MPEG-2 at a bit rate of 32-384 kbps, and supports four mono, two stereo, or 5.1 channels. Subtitles use overlays rather than subpictures (DVD-Video) or being encoded as video (VideoCD). Variable bit-rate encoding is used, with a maximum bit rate of 2.6 Mbps. IEC 62107 defines the Super VideoCD standard. XSVCD, although not an industry standard, increases the video resolution and bit rate to improve the video quality over SVCD. MPEG-2 video is still used, with a resolution of 720 x 480 (29.97 Hz frame rate) or 720 x 576 (25 Hz frame rate). Variable bit-rate encoding is still used, with a maximum bit rate of 9.8 Mbps. 
Superbit DVD See DVD-Video. 
SVCD See Super Video CD. 
SVM See velocity scan modulation. 
swap shot An insert edit where the segment of an edit sequence that lies between two transitions is swapped for the incoming source clip. Swap shots ripple, meaning the edit sequence duration changes if the source clip is of a different length than the segment it replaces.
sweep signal A signal whose frequency is varied through a given frequency range. 
sweetening Audio postproduction, at which time minor audio problems are corrected. Music, narration and sound effects are mixed with original sound elements.
switcher The device that serves as a central router and mixer of video source material in an on-line suite, and performs effects (e.g., fades and dissolves) as well as switching incoming channels. Also known as a video switcher.
sync - a IRE pulse used to ensure correct timing relationships throughout the TV system. A circuit or signal that directs the electron gun in a camera or TV picture tube to hold a picture steady on the screen. It also synchronizes the electronics of other video equipment.
sync generator An electrical device that generates sync (timing)signals used to synchronize video equipment and keep pictures stable on the screen.
Sync Noise Gate A sync noise gate is used to define an area within the video waveform where the video decoder is to look for the sync pulse. Anything outside of this defined window will be rejected. The main purpose of the sync noise gate is to make sure that the output of the video decoder is nice, clean, and correct. 
sync pulses Pulses needed by video source equipment for accurate video signal timing.
Sync Stripper A video signal contains video information, which is the picture to be displayed, and timing (sync) information that tells the receiver where to put this video information on the display. A sync stripper pulls out the sync information from the video signal and throws the rest away. 
sync word  The portion of SMPTE timecode that indicates the end of each frame and the direction of tape travel. See also timecode, time-of-day timecode.
Synchronous, (sync) Short for synchronous, the signals used to synchronize the horizontal and vertical scans of a video signal and is usually accompanied by subcarrier.
Tag Image File Format, (TIFF) A tag-based format for storing and interchanging bitmap (raster) images.
tail Video or audio material that has been trimmed out of the back (trailing) end of a clip.
take When a particular scene is repeated and photographed more than once in an effort to get a perfect recording of some special action, each photographic record of the scene or of a repetition of the scene s known as a "take". For example, the seventh scene of a particular sequence might e photographed three times, and the resulting records would be called
TDF Telediffusion de France. 
telecine A device that creates video from motion picture film.
Telecine Decision List, (TDL) A list of the edits made in a telecine session which can be loaded into an off-line editor.
Teletext A method of transmitting data with a video signal. ITU-R BT.653 lists the major teletext systems used around the world, while ETSI ETS 300 706 defines in detail the teletext standard for PAL. North American Broadcast Teletext Specification (NABTS) is 525-line system C. For digital transmissions such as HDTV and SDTV, the teletext characters are multiplexed as a separate stream along with the video and audio data. It is common practice to actually embed this stream in the MPEG video bitstream itself, rather than at the transport layer. Unfortunately there is no wide-spread standard for this teletext stream -- each system (DSS, DVB, ATSC, DVD) has its own solution. The practical place in MPEG to stick teletext data is in the user_data field, which can be placed at various frequencies within the video stream. For DVD, it is the group_of_pictures header, which usually proceed intra pictures (this happens about 2 times a second). For ATSC broadcasts the data is inserted in the user_data field of individual picture headers (up to 60 times/sec). 
temporal compression A compression method that reduces the data contained within a single video frame by identifying similar areas between individual frames and eliminating the redundancy. See also codec. 
terabyte 1 trillion bytes. A 2 hour HTDV movie at the maximum resolution of 1920 x 1084 would take about 1 terabyte to store in an uncompressed format.
Tessellated Sync This is what the Europeans call serrated sync. See serration pulses and sync. 
texture mapping Attributing a surface quality, such as a colour, roughness, smoothness, or volume to a 3D model.
thin As applied to a photographic image, having low density.
three-point editing In Adobe Premiere, the feature that enables editors to insert a clip into an existing program where only three of the four in and out points of the clip to be inserted, and the portion of the program where the clip is being inserted, are known.
tile A transition in whichone image is gradually replaced by another image that appears part-by-part in successive squares. The squares follow a given pattern until the entire screen is filled iwth the new image.
tiling A technique for displaying high-resolution images that divides images into portions (tiles) and loads the portions into memory as needed for display on screen.
time code A frame numbering system adopted by SMPTE that assigns a number to each frame of video which indicates hours, minutes, seconds and frames. A time reference recorded on tape to identify each frame. The indexing method used for timing and editing video and audio material. The numbers in a timecode denote hours, minutes, seconds and frames (00:00:00:00) elapsed on a videotape. A sequential code number assigned to successive video frames on tape. Each frame has its own time code, which is electronically encoded on the tape in the form hour:minutes:seconds:frames).
TimeBase Corrector, (TBC) An electronic device with memory and clocking circuits to correct video signal timing error which affect image stability and colour when editing from multiple video tape sources. An electronic device that, when connected to the output of a VTR, corrects the stability and timing of the VTR's playback video. This is achieved by stripping the unstable horizontal and vertical sync pulses from the video signal and replacing them with new, clean sync pulses.
timecode Generally refers to the industry standard of STPME timecode, which is formatted as four numbers separated by colons (e.g., 21:52:31:20). The numbers represent hours, minutes, seconds, and frames, and are added to video to enable precise editing. Since color video runs at 29.97 fps instead of 30 fps, two kinds of timecode have evolved: drop-frame and non-drop-frame. Non-drop-frame timecode is formatted as four numbers separated by semicolons (e.g., 21;52;31;20). There are two basic techniques used to record SMPTE timecode on videotape, longitudinal timecode (LTC) and vertical interval timecode (VITC).
timecode editing Using timecode as a precise reference for editing. Each frame has its own individual timecode number, which enables fast and frame accurate editing as well as automatic editing via an edit controller (see edit decision list). Contrast with control track editing.
timeline The graphical representation of program length onto which video, audio, and graphic clips are arranged.
timewarp Speeding up or slowing down the action in a clip by decreasing or increasing the number of frames in a clip.
timing The process of selecting the printing values for colour and density of successive scenes in a complete film to produce the desired visual effects.
tint An effect that replaces the chrominance information of an image with a single colour, but keeps the luminance levels of the image intact. The result is an image formed with shades of only one colour. This is useful for simulating "old-time" sepia images. tolerance
title generator A black-and-white camera used for shooting titles that are electronically superimposed onto the video picture during shooting or editing. A more sophisticated device know as a character generator (CG) can generate titles directly. 
titler See character generator(CG). 
tracking The angle and speed at which tape passes the video heads. Panning of the camera to maintain alignment with a moving object
transcoder A device for converting from one video component set to another (e.g., from Hi8 to Betacam SP.) 
transition The passage from one segment of video or audio to another. A transition can be in the form of a splice, dissolve, wipe or DVE wipe.
transition effect An effect (e.g., barn doors, wipe) where the elements of one clip blend with another during transition. 
transition rate The number of frames over which a dissolve or wipe occurs.
traveling matte A process shot in which foreground action is superimposed on a separately photographed background by optical printing.
Tri-Level Sync A sync signal that has three levels, and is commonly used for analog HDTV signals. See the definition for sync. 
trimming Editing a clip on a frame-by-frame basis, or editing clips in relationship to one another. 
True Color True color means that each sample of an image is individually represented using three color components, such as RGB or Y'CbCr. 
tweening The feature that fills in the frames between two images so the movement appears smoother. See also, keyframing. 
type c SMPTE standard for 1-inch non-segmented helical video recording format.
u-matic Trade name for 3/4 inch video cassette system originally developed by Sony. Now established as the ANSI (American National Standards Institute) Type F video tape format.
U-type VTR  A recorder format that uses 3/4-inch videotape.
UHF  Ultrahigh frequency. One of the television signals for broadcasting in the United States per FCC standards. UHF is the frequency between very high frequency (VHF) and super high frequency (SHF). 
ultimatte Trade name of a high-quality special effects system similar in application to a chromakey switcher. Electronic implementation of the "blue screen" used for motion picture special effects.
uncompressed video  A recorded or digitized video stream that is not processed by a data compression scheme. The video signal remains uncompressed at all stages of the process: input, storage, and output. Uncompressed video conforms to the ITU-R 601 standard. 
uncompressed-quality video Video that has the same image quality as uncompressed video, but has been compressed using mathematically lossless compression to optimize storage space.
Underscan When an image is displayed, it is "underscanned" if all of the image, including the top, bottom, and side edges, are visible on the display. Underscan is common in computer displays. On video monitors, a mode that decreases the raster size horizontally and vertically so all four edges of the picture are visible. Underscan lets you view skew and tracking, which are otherwise not visible in overscan mode. 
Undo/Redo  "The process that allows a return to the state of the edit immediately preceding the last edit or a repeat of an ""undo"" edit. "
unsqueezed print A print in which the distorted image of an anamorphic negative has not been corrected for normal projection.
up cut  In editing, to cut the end of the previous scene, often by mistake. In general, to cut short. 
Uplink The carrier used by Earth stations to transmit information to a satellite. 
user bits Portions of VITC and LTC reserved for recording information of the user's choosing, e.g. Keykode numbers, footage count etc.
V-box An interface device that can be connected to a personal computer using an RS-232 serial interface. The V-box enables the computer to control LANC-compatible video devices and translates the computer's VISCA commands into LANC protocol. 
V-LAN  A registered trademark of Videomedia, Inc. An industry-standard software protocol for video device control. The V-LAN network allows a computer application to control and synchronize all connected VTRs, switchers, DATs, mixers, and DVEs. 
value  The actual data associated with a particular property in an OMF Interchange object. 
vaporware Software or hardware that is talked about, but may never actually appear. 
Variable Bit Rate, (VBR) Variable bit rate (VBR) means that a bitstream (compressed or uncompressed) has a changing number of bits each second. Simple scenes can be assigned a low bit rate, with complex scenes using a higher bit rate. This enables maintaining the audio and video quality at a more consistent level. 
variable-speed play  A process — or an editing-system feature that enables the process — of shifting easily between the playing, stepping (jogging), and shuttling of footage. 
VBI See vertical blanking interval. 
VBV  Video-Black-Video. A preview mode that shows a previously recorded scene, a black segment, and then the previously recorded scene again. 
VCD Abbreviation for VideoCD. 
VCR Abbreviation for Video Cassette Recorder; a videotape recording device that uses videocassettes.
vector  In color correction, a subdivision of the full color spectrum defined by hue and saturation values. Secondary color correction uses vectors to define specific areas of an image to receive color adjustments. 
vector image An image described by basic geometric shapes like rectangles, polygons, circles, ellipses, lines and curves.
vectorscope An oscilloscope designed for television which is used to set up and monitor the chrominance portion of a video signal. This device graphically shows the relationship between hue and colour saturation.
Velocity Scan Modulation Commonly used in TVs to increase the apparent sharpness of a picture. At horizontal dark-to-light transitions, the beam scanning speed is momentarily increased approaching the transition, making the display relatively darker just before the transition. Upon passing into the lighter area, the beam speed is momentarily decreased, making the display relatively brighter just after the transition. The reverse occurs in passing from light to dark. 
vertical blanking See vertical interval.
vertical blanking interval  The period during which the television picture goes blank as the electron beam returns (retraces) from scanning one field of video to begin scanning the next. The vertical blanking interval is sometimes used for inserting timecode, automatic color tuning, or captioning information into the video signal. 
vertical interval Also called vertical blanking, the interval of time when the scanning retraces from the bottom back to the top of the screen. During the vertical interval, the picture is blanked. The vertical interval includes sync pulses, and when used for broadcasts, often contains network information, and test and closed captioning signals.
Vertical Interval Time Code, (VITC) A signal that can be used for in service testing by inserting it on a specific line, or lines, in the vertical interval. Timecode stored in the vertical interval of the video signal. Has the advantage of being readable by a VTR in still or jog. Multiple lines of VITC can be added to the signal allowing the encoding of more information than can be stored in normal LTC. Time code that is encoded onto the vertical blanking interval of a video signal. VITC can be read by a VTR whenever an image is displayed, but not usually during high-speed operation.
Vertical Resolution See resolution. 
vertical retrace Upon completing the field scan, the return of the electron beam to the top of a screen.
vertical scan frequency The frequency of the vertical sync pulses or vertical scans. NTSC vertical scan frequency is 59.9 Hz. 
Vertical Scan Rate For noninterlaced video, this is the same as the frame rate. For interlaced video, it is usually one-half the field rate. 
vertical sync The pulse that initiates the vertical retrace of the electron gun from the bottom of a frame back to the top.
vertical sync pulse The part of the vertical blanking interval comprising the blanking level and six pulses (92% duty cycle at -40 IRE units) at double the repetition rate of the horizontal sync pulse. The vertical sync pulse synchronizes the vertical scan of television receiver to the composite video signal, and starts each frame at same vertical position (sequential fields are offset by half a line to obtain an interlaced scan.)
Vestigial Sideband A method of encoding digital data onto a carrier for RF transmission. 8-VSB is used for over-the-air broadcasting of ATSC HDTV in the USA. 
VHF  Very high frequency. One of the television signals for broadcasting in the United States per FCC standards. VHF is the frequency between high frequency (HF) and ultrahigh frequency (UHF). 
VHS  Video Home System. The 1/2-inch videocassette format developed by JVC for consumer and industrial use. 
video (1) A means for reproducing moving visual images by representing them with an analog electronic signal. The images are decomposed into a series of horizontal scan lines. In this way the signal can be stored, transmitted and reproduced. (See rasterization, field, frame.) (2) There are various standards that define this signal, See NTSC, PAL, SECAM, RGB. (3) Referring to the NTSC composite video standard. This is a widespread standard such that the video in of one machine is compatible with the video out of another.
video capture card See capture card. 
Video Carrier A specific frequency that is modulated with video data before being mixed with the audio data and transmitted. 
video distribution amplifier A special amplifier for strengthening the video signal so that it can be supplied to a number of video monitors or other devices at the same time. Also called a distribution amplifier, or DA. 
video editing The selecting and arranging of frames on the edit master videotape. In professional applications, video editing must usually be frame-accurate. Contrast with assemble edit, off-line edit, and on-line edit. 
Video For Windows See AVI. 
video format A standard that determines the way a video signal is recorded onto videotape. Standards include: DV, Digital 8, 1-inch Type C, 3/4" U-Matic, 3/4" U-Matic, 8mm, Beta, Beta ED, Betacam, Betacam SP, SP, D-1, DCT, D-2, D-3, D-5, Digital Betacam, Hi8, M-II, VHS, and S-VHS. 
Video Interface Port, (VIP) A digital video interface designed to simplify interfacing video ICs together. One portion is a digital video interface (based on BT.656) designed to simplify interfacing video ICs together. A second portion is a host processor interface. VIP is a VESA specification. 
Video Mixing Video mixing is taking two independent video sources (they must be genlocked) and merging them together. See alpha mix. 
Video Modulation Converting a baseband video signal to an RF signal. 
Video Module Interface A digital video interface designed to simplify interfacing video ICs together. It is being replaced by VIP. 
video monitor A display device that receives video signals via direct connection and does not receive broadcast signals (e.g., commercial television). A video monitor can be connected directly to a computer. 
Video Program System VPS is used in some countries instead of PDC to control VCRs. The data format is the same as for PDC, except that it is transmitted on a dedicated line during the vertical blanking interval, usually line 16. 
video recording The converting of an image, moving or still, into a video signal that can then be recorded. Video recording is usually performed by using of a video camera. 
video signal The dynamic signal representing the varying levels of a video image, but not containing the sync pulses for its display. The video signal can be combined with the sync pulses into a composite signal. 
Video Slave Driver  "A trademark of Avid Technology, Inc. A hardware component that synchronizes signal inputs, outputs, and conversions; selects audio frame rates; and selects pulldown of video frames. "
video source In editing, the players running the original video tapes. 
video stream  1. In analog editing systems, also called a video playback source. 2. In digital editing systems, a stream of data making up a digital video image.
video switcher See switcher. 
Video-on-Demand, (VOD) Video-on-demand, or VOD, allows a user to select which program to view at their convenience and playing starts almost immediately. When used over the Internet or other network, it is commonly called "streaming video". For broadcast, satellite and cable networks, it is commonly called "pay-per-view" and is usually confined to specific start times. For this reason, it may also be referred to as "near video-on-demand" or nVOD. 
videocassette  A plastic shell containing two reels and a length of videotape. 
VideoCD Compact discs that hold up to about an hour of digital audio and video information. MPEG-1 video is used, with a resolution of 352 x 240 (29.97 Hz frame rate) or 352 x 288 (25 Hz frame rate). Audio uses MPEG-1 layer 2 at a fixed bit rate of 224 kbps, and supports two mono or one stereo channels (with optional Dolby pro-logic). Fixed bit-rate encoding is used, with a bit rate of 1.15 Mbps. The next generation, defined for the Chinese market, is Super VideoCD. XVCD, although not an industry standard, increases the video resolution and bit rate to improve the video quality over VCD. MPEG-1 video is still used, with a resolution of up to 720 x 480 (29.97 Hz frame rate) or 720 x 576 (25 Hz frame rate). Fixed bit-rate encoding is still used, with a bit rate of 3.5 Mbps. 
videotape A magnetic recording medium that can store an electronic signal and is made of backing, binder, and coating. The coating is generally made of iron oxide, but may also be made of metal particle or metal evaporated coatings. 
view A view of the animation scene from the camera eye, equivalent to the viewing frustrum of the camera. In Perpective View, an object's size depends on its distance from the camera.
virtual source A source clip that generates new frames as needed; it has no real beginning or end. Virtual sources can be trimmed to any extent.
VISCA The abbreviation for Video System Control Architecture; a device control language for synchronized control of multiple video devices. The VISCA protocol is device- and platform-independent. See also LANC and V-Box. 
vision mixer British video switcher.
VITC  Vertical interval timecode. The timecode inserted in the vertical blanking interval. Compare with LTC. See also timecode. 
VLXi  A registered trademark of Videomedia, Inc. A series of controllers that control and synchronize professional video equipment for animation, video editing, HDTV, and broadcast television production. 
VMI See video module interface. 
VOB Files DVD-Video movies are stored on the DVD using VOB files. They usually contain multiplexed Dolby Digital audio and MPEG-2 video. VOB Files are named as follows: vts_XX_Y.vob where XX represents the title and Y the part of the title. There can be 99 titles and 10 parts, although vts_XX_0.vob never contains video, usually just menu or navigational information. 
voice over Narration added over video. The narrator, who is not recorded with the original video, explains or somehow supplements the visual images.
VPS See video program system. 
VSB See vestigial sideband. 
VSM See velocity scan modulation. 
VSYNC Check out the vertical sync definition. 
VTR Abbreviation for Video Tape Recorder; an electromechanical device that can record, store, and reproduce an electronic signal that contains audio, video, and control information. This term also refers to reel-to-reel and cassette recorders (e.g., VCRs) . 
VU meter  Volume unit meter. An instrument used to measure audio levels. 
VVV  Video-Video-Video. A preview mode that shows a previously recorded scene, the new insert video, and then the previously recorded scene again.
warping A free-form image distortion. 
WAVE  RIFF Waveform Audio File Format. A widely used format for audio data. OMF Interchange includes it as a common interchange format for audio data. 
waveform  In video, a visual display that shows the electronic pattern of the video signal. It is used to adjust the setup and gain using a stable reference such as color bars. The Avid waveform uses a 
waveform monitor Oscilloscope designed for television which looks at luminance and all other parts of the composite video signal. Graphically displays the level of a video signal.
weave Periodic sideways movement of the image as a result of mechanical faults in camera, printer or projector.
wet-gate printing A system of printing in which the original is temporarily coated with a layer of liquid at the moment of exposure to reduce the effect of surface faults.
whip  A horizontal picture disturbance at an edit point, usually caused by timing misadjustments in the edit system. 
white balance The colour balancing procedure for a video camera. Allows a camera to "see" white under a given lighting condition.
White Level This level defines what white is for the particular video system. 
white point  The luminance value in a video image that you set to be equal to reference white when making a color adjustment. Compare with black point. 
Wide Screen Signaling WSS may be used on (B, D, G, H, I) PAL line 23 and (M) NTSC lines 20 and 283 to specify the aspect ratio of the program and other information. 16:9 TVs may use this information to allow displaying of the program in the correct aspect ratio. ITU-R BT.1119 and ETSI EN 300 294 specify the WSS signal for PAL and NTSC systems. EIA-J CPR-1204 and IEC 61880 also specify another WSS signal for NTSC systems. 
widescreen General term for form of film presentation in which the picture shown has an aspect ratio greater than 1'33:1.
wild sound, wild track  A recording of sound on either videotape or audiotape made without an accompanying picture. 
window dub Burned-in windows, usually on a video workprint, displaying Keykode numbers and time code, footage count, audio time code, scene, etc. (May also be burned in.)
window dubs In off-line editing, the transfer of material onto a more affordable tape format (e.g., 3/4-inch or Hi8 tape) with the timecode burned in on the picture. Window dubs enable you to view the timecode on a VCR without a timecode reader, and ensure frame accuracy during off-line editing when a non-frame-accurate edit controller is in use. 
wipe Optical transition effect in which one image is replaced by another at a boundary edge moving in a selected pattern across the frame. A transition in which one image is gradually replaced by another image that is revealed in a given pattern. For example, the second image could be revealed from the top of the screen downwards until it fills the entire screen.
wipe  A shaped transition between video sources in which a margin or border moves across the screen, wiping out the image of one scene and replacing it with another. 
wireframe A display option where solid or filled objects are represented by a mesh lines and/or curves.
work print  A film print made from the original negative that is used during the editing process to produce a cut list or edit decision list for final program assembly. Work prints are typically low-cost, one-light prints that receive heavy wear through repeated handling. See also answer print, print, release print.
World System Teletext BT.653 525-line and 625-line system B teletext. 
WSS See wide screen signaling. 
WST See world system teletext. 
XSVCD Abbreviation for eXtended Super VideoCD. See Super VideoCD. 
XVCD Abbreviation for eXtended VideoCD. See VideoCD. 
Y  The luminance signal of the component color system in the NTSC video standard. The signal is composed of the following proportions of red, green, and blue: 0.299R + 0.587G + 0.114B See also B–Y, R–Y. 
Y axis  The vertical axis in a three-dimensional system. See also X axis, Z axis. 
Y, B–Y, R–Y  The luminance and color difference signals of the component color system in the NTSC video standard. Also called YCrCb. 
Y'CbCr, YCbCr Y'CbCr is the color space originally defined by BT.601, and now used for all digital component video formats. Y' is the luma component and the Cb and Cr components are color difference signals. The technically correct notation is Y'Cb'Cr' since all three components are derived from R'G'B'. Many people use the YCbCr notation rather than Y'CbCr or Y'Cb'Cr'. 4:4:4 Y'CbCr means that for every Y' sample, there is one sample each of Cb and Cr. 4:2:2 Y'CbCr means that for every two horizontal Y' samples, there is one sample each of Cb and Cr. 4:1:1 Y'CbCr means that for every four horizontal Y' samples, there is one sample each of Cb and Cr. 4:2:0 Y'CbCr means that for every block of 2 x 2 Y' samples, there is one sample each of Cb and Cr. There are three variations of 4:2:0 YCbCr, with the difference being the position of Cb and Cr sampling relative to Y. Note that the coefficients to convert R'G'B' to Y'CbCr are different for SDTV and HDTV applications. 
Y'IQ, YIQ Y'IQ is a color space optionally used by the NTSC video system. The Y' component is the black-and-white portion of the image. The I and Q parts are the color difference components; these are effectively nothing more than color placed over the black and white, or luma, component. Many people use the YIQ notation rather than Y'IQ or Y'I'Q'. The technically correct notation is Y'I'Q' since all three components are derived from R'G'B'. 
Y, Pb, Pr A version of component video (Y, R-Y, B-Y) specified for the SMPTE analog component standard. 
Y'PbPr, YPbPr Y'PbPr is a scaled version of the YUV color space, with specific levels and timing signals, designed to interface equipment together. Consumer video standards are defined by EIA-770; the professional video standards are defined by numerous SMPTE standards. VBI data formats for EIA-770 are defined by EIA-805. Many people use the YPbPr notation rather than Y'PbPr or Y'Pb'Pr'. The technically correct notation is Y'Pb'Pr' since all three components are derived from R'G'B'. 
Y, R-Y, B-Y The general set of CAV signals used for PAL as well as some encoder and most decoder applications in North American and Japanese NTSC systems, where Y represents the luminance signal, R-Y represents the first color difference signal, and B-Y represents the second color difference signal. 
Y, U, V The luminance and color difference components for PAL systems. Y, U, V is simply Y, R-Y, B-Y renamed. 
Y'UV, YUV Y'UV is the color space used by the NTSC and PAL video systems. As with the Y'IQ color space, the Y' is the luma component while the U and V are the color difference components. Many people use the Y'UV notation when they actually mean Y'CbCr data. Most use the YUV notation rather than Y'UV or Y'U'V'. The technically correct notation is Y'U'V' since all three components are derived from R'G'B'. YUV is also the name for some component analog interfaces on consumer equipment. Some manufacturers incorrectly label it YCbCr. THX certification will require it to be labeled YPbPr. 
Y/C Delay A delay between the luminance (Y) and chrominance (C) signals. 
Y/C Separator A Y/C separator is what's used in a video decoder to separate the luma and chroma in a NTSC or PAL system. This is the first thing that any video decoder must do. The composite video signal is fed to a Y/C separator so that the chroma can then be decoded further. 
Y/C video A component video signal in which the luminance (Y) and chrominance (C) informatio are separate. S-VHS videocasette recorders use th Y/C video format.
YCC A video signal comprising luminance (Y) and two chrominance (C) components. 
YCrCb  See Y, B–Y, R–Y, YUV. 
YUV  The letter designations for luminance, luminance minus red, and luminance minus blue. YUV are the luminance and color difference signals of the component video standard for PAL. Also called YCrCb.
YUV12 Intel's notation for MPEG-1 4:2:0 YCbCr stored in memory in a planar format. The picture is divided into blocks, with each block comprising 2 x 2 samples. For each block, four 8-bit values of Y, one 8-bit value of Cb, and one 8-bit value of Cr are assigned. The result is an average of 12 bits per pixel. 
YUV9 Intel's 4:1:0 YCbCr format. The picture is divided into blocks, with each block comprising 4 x 4 samples. For each block, sixteen 8-bit values of Y, one 8-bit value of Cb, and one 8-bit value of Cr are assigned. The result is an average of 9 bits per pixel. 
YUY2 Intel's notation for 4:2:2 YCbCr format. 
Z axis  The axis that is perpendicular to the X and Y axes in a three-dimensional system. 
zebra pattern A camera viewfinder display that places stripes over a part of an image which has reached a pre-determined video level, usually set at about 70 IRE units and used to ensure correct exposure of skintones.
zero duration dissolve  "The method of editing two scenes end-to-end simultaneously; also called a cut."
Zoom Zoom is a type of image scaling. Zooming is making the picture larger so that you can see more detail. The examples described in the definition of scaling are also examples that could be used here. 
zoom lens A type of camera lens that can adjust focal length while maintaining focus. A zoom lens enables the appearance of approaching or withdrawing from an object. 
Zoomed Video Port, (ZV Port) Used on laptops, the ZV Port is a point-to-point uni-directional bus between the PC Card host adapter and the graphics controller, enabling video data to be transferred real-time directly from the PC Card into the graphics frame buffer. The PC Card host adapter has a special multimedia mode configuration. If a non-ZV PC Card is plugged into the slot, the host adapter is not switched into the multimedia mode, and the PC Card behaves as expected. Once a ZV card has been plugged in and the host adapter has been switched to the multimedia mode, the pin assignments change. The PC Card signals A4-A25, SPKR#, INPACK# and I0IS16# are replaced by ZV Port video signals (Y0-Y7, UV0-UV7, HREF, VSYNC, PCLK) and 4-channel audio signals (MCLK, SCLK, LRCK, and SDATA). 
zooming The enlarging or minimizing of an image on a computer monitor to facilitate ease of viewing and accurate editing. 
Zweiton A technique of implementing stereo or dual-mono audio for NTSC and PAL video. One FM subcarrier transmits a L+R signal, and a second FM subcarrier transmits a R signal (for stereo) or a second L+R signal. It is discussed in BS.707, and is similar to the BTSC technique.