aspect ratio -- The shape of an image or frame, expressed as the width-to-height ratio. Widescreen film uses a 16:9 aspect ratio (1.78:1), whereas standard television uses 4:3 aspect ratio (1.33:1). A DVD disc can store video in either standard or widescreen format. DVD players can automatically format widescreen video for display on standard televisions letterboxing or pan and scan. See also anamorphic, letterbox, Pan and scan.
widescreen -- A wide picture format for film at 16:9 aspect ratio. See also aspect ratio.
4:3 -- Standard aspect ratio used for television; one third wider than it is high (1.33:1). See also aspect ratio.
16:9 -- Widescreen aspect ratio used for film; almost twice as wide as it is high (1.78:1). See also aspect ratio.
letterbox -- A technique used to display a widescreen video image (with a 16:9 aspect ratio) on a standard television display (with a 4:3 aspect ratio). The widescreen image fills the width of the screen, with black bars above and below it. See also aspect ratio, pan and scan.
anamorphic -- A method of storing widescreen video on DVDs. The original 16:9 widescreen image is squeezed horizontally and stored on disc in the standard 4:3 video resolution or typically letterboxed on a standard television monitor, or cropped to 4:3 aspect ratio. The DVD player then stretches it back out to the original aspect ratio for display, either to a widescreen monitor or typically letterboxed on a standard television monitor. See also aspect ratio.
pan and scan -- A technique used to crop a widescreen film (with a 16:9 aspect ratio) to store and display it at standard 4:3 aspect ratio. Instead of just cutting off the two sides of the widescreen image, an operator pans a 4:3 window within the full widescreen frame in order to show the most important speaker or action. See also aspect ratio, letterbox.
split-screen -- A divided display that shows two clips, or portions of clips, side by side.
overscan -- The outer edges of a video image that are typically cut off by consumer television sets in order to ensure that the image fills the entire display. See also safe area.
safe area -- Also known as the safe zone. Margins left around the edge of the image. Used when working with material intended for display on television. Safe margins keep titles from bleeding off the screen. See also overscan.
analog media -- Audio sources, such as audio cassettes and microphones, and video sources, such as VHS and 8mm VCRs and camcorders, that must be digitized and converted into digital format for processing by a computer. Newer digital formats such as DV and DVD have higher resolution and quality than older consumer formats like VHS, and also do not degrade in quality when they are copied from one generation to the next. See also component video, composite video, digital media.
digital media -- Audio and video sources such as audio CD, DV, miniDV, Digital8 camcorders, and DVD that store the audio and video in digital format. As a result, the data can be imported and processed directly by a computer, and copied without any loss from one generation to the next. See also analog media, DV.
VTR -- Video Tape Recorder. Also called VCR (Video Cassette Recorder).
composite video -- A video signal that combines the brightness (luminance or luma) and the color (chrominance or chroma) video information into one signal. Because the signal is not modulated, composite video provides higher quality than RF video. Requires a separate audio signal and connector. Also called Baseband video. See also component video, DV, RF video, S-Video.
component video -- A video signal that separates the video signal into three separate signals (and three separate wires) to avoid any quality loss from mixing signals. The components can be RGB (red, green, and blue); luma (Y) and two chroma signals, such as Y, Y-R, Y-B; or other formats including YUV, YCbCr, or Y Pr Pb. Requires a separate audio signal and connector. See also composite video, DV, RF video, S-Video.
luminance -- The intensity or brightness of a video signal, usually represented by the letter Y. Video signals are split into separate luma and chroma (color) components for higher-quality and more efficient transmission and encoding. In YUV color format, for example, the color information stored in U and V (the color difference signals).
chrominance -- The color of a video signal. Video signals are split into separate luma and chroma (color) components for higher-quality and more efficient transmission and encoding. The chroma signal is typically split into two components or color difference signals, such as YUV format. See also luminance.
RGB -- Acronym for Red, Green, Blue. Full-color video signal format, consisting of three elements. See also YUV.
YUV -- Full-color video signal format, consisting of three elements: Y (luminance), and U and V (chrominance). See also RGB.
field -- For interlaced video sources, a full frame is constructed from alternating odd and even lines from two video fields captured at slightly different times. See also interlaced video.
frames -- The individual video images that make up a moving sequence. Video formats and individual clips are typically described in terms of the resolution of the individual frames, and the frame rate at which they are played. See also frame rate, field.
frame rate -- Playback speed as determined in frames per second (fps). See also sample rate.
progressive video -- Video consisting of complete frames, not interlaced fields. Each individual frame is a coherent image captured by the camera at a single moment in time. See also interlaced video.
progressive scan -- Video display in which the entire screen in refreshed (redrawn) at once. Typically used for computer monitors and high-end video systems. See also interlaced video.
interlaced video -- A technique used for television video formats, such as NTSC and PAL, in which each full frame of video actually consists of alternating lines taken from two separate fields captured at slightly different times. The two fields are then interlaced or interleaved into the alternating odd and even lines of the full video frame. When displayed on television equipment, the alternating fields are displayed in sequence, depending on the field dominance of the source material. See also progressive video.
deinterlace -- To process interlaced television video, in which each frame contains alternating pairs of lines from two separate fields captured at slightly different times. The motion between fields can cause visible tearing when displayed on a computer monitor. Deinterlacing uses every other line from one field and interpolates new in-between lines without tearing. See also interlace, NTSC.
2-3 / 3-2 pulldown -- Process used to convert material from film to interlaced NTSC display rates, from 24 to 30 frames per second. This is done by duplicating fields, 2 from one frame and then 3 from the next frame (or 3 and then 2). Both terms are often used interchangeably to describe the effect. See also inverse telecine.
inverse telecine -- The process used to reverse the effect of 3-2 pulldown, removing the extra fields inserted to stretch 24 frame per second film to 60 field per second interlaced video. See also 2-3/3-2 pulldown.
master -- For video, the original video or audio source, or final video production with analog media, the first tape you create from your PC video file, also known as the first-generation tape. The master tape is a high-quality source to which you should return whenever you want to make more copies. Although you could use the file on your hard drive as a master, you won't want to keep that file forever because it takes up so much storage space. If you're using analog video, however, the PC file is your master source and first generation; the first physical tape you record is considered to be a second-generation tape. See also analog media, DV, digital media.
talking head -- A clip that shows just the head and shoulders of a person who is talking. This tight focus is often used in interview situations where the background is not as important as the talking subject. It is also convenient in a movie destined for the Web because the small amount of movement in a talking-head shot compresses well for the Internet.
freeze frame -- A technique in which a particular frame of video is held onscreen. Sometimes the audio portion of the scene continues playing.
still frame -- A single image or single frame of a video clip. See also freeze frame.
leader -- The beginning of the physical tape on a videocassette or extra material before the beginning of a clip. A tape leader is a strip of nonrecording material that connects the actual recording tape to the spindle on the cassette. Most cassette tapes have about five seconds of leader before the actual recording media portion of the tape begins.
preroll -- To start a tape spinning up to speed before beginning playback or capture to ensure that the operation is synchronized properly.
stripe -- To prepare a new videotape for a recording by prerecording a consistent timecode over the full length of the tape.
dub -- To duplicate or make a copy of a production, traditionally from one tape (usually a master tape) to another tape.
timecode -- An exact time used to identify a specific frame in a clip or production. Measured in hours, minutes, seconds, and frames. See also duration.
synchronize -- To keep two sequences playing at the same rate (in sync). A slide show or a series of video clips can be synced to the beat on an audio track. A talking-head video needs to maintain lip-sync, so that the audio matches the mouth movements of the speaker.
- Connection -
DVI-- The Digital Visual Interface, DVI connector usually contains pins to pass the DVI-native digital video signals. In the case of dual-link systems, additional pins are provided for the second set of data signals.
Use for high definition tv or other imput.
The DVI connector may also incorporate pins to pass through the legacy analog signals using the VGA standard. This feature was included in order to make DVI universal, as it allows either type of monitor (analog or digital) to be operated from the same connector.
The DVI connector on a device is therefore given one of three names, depending on which signals it implements:
* DVI-D (digital only)
* DVI-A (analog only)
* DVI-I (digital & analog)
The connector also includes provision for a second data link for high resolution displays, though many devices do not implement this. In those that do, the connector is sometimes referred to as DVI-DL (dual link).
HDMI-- The High-Definition Multimedia Interface HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It is independent of the various DTV standards such as ATSC, and DVB(-T,-S,-C), as these are encapsulations of the MPEG data streams, which are passed off to a decoder, and output as uncompressed video data, which can be high-definition. This video data is then encoded into TMDS for transmission digitally over HDMI. HDMI also includes support for 8-channel uncompressed digital audio. Beginning with version 1.2, HDMI now supports up to 8 channels of one-bit audio. One-bit audio is what is used on Super Audio CDs.
HDCP-- High-Bandwidth Digital Content Protection, HDCP's main target is to prevent transmission of non-encrypted high definition content.
COMPONENT VIDEO-- is a type of analog video information that is transmitted or stored as two or more separate signals. Component video can be contrasted with composite video (such as NTSC or PAL) in which all the video information is combined into a single signal such as a TV broadcast. Currently, component video connections are gradually being superseded by the higher quality digital DVI and HDMI interface.
Component video is capable of producing signals such as 480p, 720p, 1080i and 1080p, but digital connections such as DVI (video only) and HDMI (which can also include up to 8 channels of audio) give better results at the higher resolutions (up to 1080p). HDMI also includes both a video and audio signal in a single cable.
SEPARATE VIDEO (S-video)-- is an analog video signal that carries the video data as two separate signals (brightness and colour), unlike composite video which carries the entire set of signals in one package. S-Video works in 480i or 576i resolution. Good quality better than Scart.
SCART-- (from Syndicat des Constructeurs d'Appareils Radior cepteurs et Televiseurs) is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together. It is also known as Puritel (especially in France, where the SCART word is not normally used) and Euroconnector.
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