ActiveMovie*
Microsoft's architecture for the control and processing of streams of multimedia data and software that uses this architecture to play digital video and sound. It is intended to supersede Video for Windows*. See Video for Windows.

alias
On the Macintosh*, a pointer to the location of an original document. Instead of duplicating a file in several locations, the file exists in one place but has aliases referencing it from other locations. A file alias consumes less disk space.

AVI
Audio Video Interleaved: the Video for Windows file format for digital video and audio. See Video for Windows.

bandwidth
The amount of data that can be transferred or processed per unit of time.

bidirectional prediction
A form of compression in which the codec uses information not only from frames that have already been decompressed, but also from frames yet to come. The codec looks in two directions: ahead as well as back. This helps avoid large spikes in data rate caused by scene changes or fast movement, improving image quality. Compare unidirectional prediction.

bitmap
An image consisting of an array of pixels that can be displayed on a computer monitor.

bits per pixel
The number of bits used to represent the color information of a pixel.

brightness
The value of a pixel along the black-white axis.

to capture
The process of digitizing the analog video signal. See digitize.

CD
Compact Disc: a 4.75" disc used to store optical, machine-readable, digital data that can be accessed with a laser-based reader such as a CD player.

CD­ROM
Compact Disc Read-Only Memory: a compact disc used for computer data and applications that cannot be modified and can be accessed with a CD­ROM drive. See CD.

chroma key
A technique allowing video technicians to place foreground objects over synthesized backgrounds, such as a TV meteorologist who appears to be standing in front of a map, when in fact he or she is merely standing in front of a blue wall. Chroma key circuitry electronically separates the foreground pixels representing the meteorologist from the blue background pixels and overlays the meteorologist on top of an electronically generated weather map. Compare transparency.

chrominance
The color component of a video signal that includes information about hue and saturation. See hue, saturation. Compare luminance.

clip
A video file.

codec
A software driver used to compress and decompress video originally digitized from an analog source.

color model
Any of several means of specifying colors according to their individual components. See RGB, YUV.

component video
A video signal format that separates chrominance and luminance into two waveforms. See S video. Compare composite video.

composite video
A video signal format that includes all the visual information in one waveform, including chrominance, luminance, blanking pedestal, field, line, color sync pulses and field equalizing pulses. Compare component video.

to compress
The process of converting video and audio data into a more compact form for storage or transmission. Compare decompress.

contrast
The range between the darkest tone and the lightest tone in an image.

data rate
The speed of a transfer process, usually expressed in kilobytes (thousands of bytes) per second.

to decode
The process of decompressing a video clip and then converting its color space of from YUV to RGB. See decompress, RGB, YUV. Compare encode.

to decompress
The process of converting video and audio data from its compact form back into its original form in order to play it. Compare compress.

delta frame
A frame containing only the data that has changed since the last frame. Delta frames are an efficient means of compressing image data. Compare key frame.

device driver
Software to enable a computer to access or control a peripheral device, such as a printer.

to digitize
The process of turning an analog signal into digital data.

digital video
A video signal represented by computer-readable binary numbers that describe colors and brightness levels.

to drop (frames)
To fail to play every frame in a video file, usually because of performance limitations of the system playing the video.

to dither
The process of representing a color by mixing dots of closely related colors.

to encode
In the context of Indeo video, the process of converting the color space of a video clip from RGB to YUV and then compressing it. See compress, RGB, YUV. Compare decode.

field
One half of a video frame, consisting of every other row (scan line). See frame, interlacing.

first-frame analysis
A transparency technique wherein the first frame of the video file is a dummy frame that supplies the color or range of colors to be rendered as transparent: the color of the chroma-key background, for example. See transparency, transparency frame.

to flatten
The process of converting a Macintosh file into a self-contained, single-forked file so that it is compatible with a Windows environment. See self-contained, single-forked.

frame
One video or film image in a clip.

frame rate
The number of frames per second at which a video clip is displayed.

full motion video
Video that plays at thirty frames per second (NTSC) or 25 frames per second (PAL).

hue
Color.

Hz
An abbreviation for Hertz: cycles per second.

hybrid CD­ROM
A single disc containing files for both a Windows PC and a Macintosh. See CD-ROM.

hybrid wavelet transform
A combination of wavelet and transform algorithms within the same compression technology.

Indeo video
Intel's series of compressor and decompressor technologies for digital video, capable of producing software-only video playback.

Indeo video interactive
Intel latest compressor and decompressor for digital video, incorporating such special features as transaprency, scalability, and local decode. See Indeo video, local decode, scalability, transparency.

interframe compression
A form of compression in which the codec compresses the data within one frame relative to others. These relative frames are called delta frames. See delta frame, key frame. Compare intraframe compression.

interlacing
The process of drawing a frame by alternately drawing the rows of each field, creating the illusion that the image is being redrawn twice as often as it actually is. See field.

intraframe compression
A form of compression in which the codec compresses the data within one frame relative only to itself. Key frames are compressed with intraframe compression because they must reconstruct an entire image without reference to other frames. See delta frame, key frame. Compare interframe compression.

ISVR Pro
See Smart Video Recorder Pro.

JPEG
Joint Photographic Expert Group: a standard for compressing single images with high quality.

key frame
A frame containing all the data representing an image, rather than just the data that has changed since the last frame. The first frame of every video file is a key frame; in addition, they occur throughout the file to refresh image quality and permit certain operations, such as random user access. Compare delta frame.

local decode
A feature of Indeo video interactive allowing the playback application to tell the codec to decode only a rectangular subregion of the source video image: the viewport. See viewport.

lossless compression
Compression after which all of the original data can be recovered with decompression. See to compress. Compare lossy compression.

lossy compression
Compression after which some portion of the original data cannot be recovered with decompression. Such compression is still useful because the human eye is more sensitive to some kinds of information than others, and therefore does not necessarily notice the difference between the original and the decompressed image. See to compress. Compare lossless compression.

luminance
The component of a video signal that includes information about its brightness. See brightness. Compare chrominance.

MCI
Media Control Interface: Microsoft's interface for controlling multimedia devices such as a CD­ROM player or a video playback application.

MPEG
Motion Picture Expert Group: a standard for compressing motion pictures-video-with high quality. In addition to compressing single images-frames-frames are compressed relative to each other as well. See interframe compression.

MooV
The file format used in the QuickTime and QuickTime for Windows environments for displaying videos. See QuickTime, QuickTime for Windows.

MOV
The file extension used by MooV format files on Windows. See MOV.

multimedia
Information that combines some or all of text, still images, sound, animation, and video.

native resolution
The resolution at which the video file was captured.

NTSC
National Television Systems Committee: a committee of the Electronic Industries Association that prepared the standards for commercial television broadcasting in the United States, Canada, Japan, and parts of Central and South America.

NTSC format
A color television format having 525 scan lines (rows) of resolution at thirty frames per second (30 Hz). See NTSC. Compare PAL format.

offline encoder
The Indeo video codec's normal mode of operation, in which it takes as long as necessary to encode a video file so that it displays the best image quality and the lowest and most consistent data rate. Compare quick compressor.

PAL
Phase Alteration Line: the standard for commercial television broadcasting in most of Europe, Australia, parts of Central and South America, and other countries.

PAL format
A color television format having 625 scan lines (rows) of resolution at 25 frames per second (25 Hz). See PAL. Compare NTSC format.

palette
A look-up table of 256 color values.

palette flash
A phenomenon caused by simultaneously displaying more than one bitmap or video that do not share the same palette.

pixel
Picture element: the smallest independently accessible unit of a digital image.

pixel depth
The number of bits of color information per pixel. A system using eight bits per pixel can display 256(2⁸) colors. A system using 16 bits per pixel can display 65,536(2¹⁶) colors. A system using 24 bits per pixel can display over 16.7 million colors. Twenty-four­bit color is often called true color because the human eye can distinguish among approximately six million different colors, or fewer than are available in a 24-bit color system.

quick compressor
A compressor compatible with Indeo video interactive that handles data more quickly than the offline compressor. Videos that compress in hours can take minutes using the quick compressor. Compare offline encoder.

QuickTime
Apple's multimedia environment for its Macintosh operating system. Installing System 7.5 or later automatically installs QuickTime by adding extensions to your System folder.

QuickTime for Windows
Apple's multimedia playback environment for Microsoft's Windows operating system. You use QuickTime for Windows by installing several drivers and libraries on your hard disk.

raw
A bitstream format in which the video data is uncompressed. See to compress, to encode.

resolution
The width and height of the video window, in pixels.

RGB
A color model used chiefly for computer displays in which colors are specified according to their red, green, and blue components. Compare YUV.

S video
See component video.

scalability
A feature of the Indeo video codec with which quality can be optimized during playback depending on the system resources being used to play the video.

saturation
The amount of gray, as opposed to hue, in a color-the intensity of the hue. See hue.

self-contained
A MooV file that contains all of its video and audio data, instead of including references to data in other files. See MooV.

single-forked
A MooV file whose resources have been moved into the data fork, creating a file that can be played on a PC. See MooV.

Smart Video Recorder Pro
Intel's PC video capture card that can capture and even compress video in real-time, using Indeo technology.

transparency
A feature of the Indeo video interactive codec in which software emulates chroma keying, allowing foreground video objects to be composited dynamically over a different background-a bitmap or possibly even another video. See chroma key.

transparency frame
In the transparency technique first-frame analysis, the first frame of the video file. It contains no video data, but merely supplies the color or range of colors to be rendered as transparent. See first-frame analysis, transparency.

unidirectional prediction
A form of compression in which the codec uses information only from frames that have already been decompressed. Compare bidirectional prediction.

Video for Windows
Microsoft's older multimedia environment for the Windows operating system. You use Video for Windows by installing several drivers and libraries in your Windows directories.

viewport
A rectangular subregion of the video image that is displayed using local decode. See local decode.

wavelet
A compression algorithm that samples the video image based on frequency to encode the information. This creates a series of bands representing the data at various levels of visual detail. The image is restored by combining bands sampled at low, medium, and high frequencies.

YUV
A color model used chiefly for video signals in which colors are specified according to their luminance-the Y component-and their hue and saturation-the U and V components. See hue, luminance, saturation. Compare RGB.

YVU9
A bitstream format that does not compress the video signal, but converts it from the RGB into the YUV color model and averages pixel colors so that the signal uses only nine bits per pixel. See to compress, to encode, RGB, YUV. Compare YVU9C.

YVU9C
A bitstream format that converts the video signal from the RGB into the YUV color model, averages pixel colors so that the signal uses only nine bits per pixel, and then compresses the signal slightly. See to compress, to encode, RGB, YUV. Compare YVU9.

* Legal Stuff © 1997 Intel Corporation