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Manifest Technology Making Sense of Digital Media Technology By Douglas Dixon |
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Resources: | PC Video | Web Media | CD & DVD | Wireless Media | Home Media | PC Technology | PC Video: | PC Video Articles | Video Software Gallery | Video Editing Resources | Video Resources: | Digital Video References | Video Terminology | Video Glossary | Video Software Gallery | Pro Software Gallery |
Common terms from digital video and audio editing and Adobe Premiere, including analog formats, multimedia file and compression formats, and data size and rate measurements. Derived from How to Use Adobe Premiere. Used with permission. See Digital Video Editing Termonology for these terms organized in related categories. See the DVD Authoring Glossary for terms from DVD authoring, including DVD and CD optical media formats, DVD video and audio formats, and home theatre and surround-sound audio. 1-9 - A - B - C - D - E - F - G - H - I - J - K - L -- Glossary M - Z - 1 - 9 -1.33 -- Standard aspect ratio used for television; one third wider than it is high (4:3). See also aspect ratio. 1394 -- See FireWire. 16:9 -- Widescreen aspect ratio used for film; almost twice as wide as it is high (1.78:1). See also aspect ratio. 1.78 -- Widescreen aspect ratio used for film; almost twice as wide as it is high (16:9). See also aspect ratio. 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. 4:3 -- Standard aspect ratio used for television; one third wider than it is high (1.33:1). See also aspect ratio. - A -A/B editing -- A style of video editing in which you edit together clips in pairs - A and B - typically with a transition from one to the next. In Premiere, the A/B Editing workspace configures the Monitor window in Program view and the Timeline with separate expanded tracks for Video 1A, Video 1B, and Transitions. This style is useful for assembling a program with simple drag-and-drop convenience. See also single-track editing. AIFF -- Acronym for Audio Interchange File Format; Macintosh audio file format. Can be used for uncompressed and compressed data. See also WAV. alpha channel -- Extra information stored with an image to define transparent areas used for keying and superimpositions. Also called an alpha mask. Sometimes present in files prepared using a tool such as Adobe Photoshop or Illustrator. See also key. amplify -- Increase the audio volume. 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. animate -- To move and manipulate an object over time, such as a title, a superimposed logo, or a transition between frames. 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. antialias -- To smooth out a jagged or stair-step appearance or motion between adjacent points so that it appears continuous. 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. attenuate -- To reduce audio strength or volume. Audio Effects palette -- A small floating window along the right side of the Premiere workspace that lists the available audio effects, grouped by type. Used to access effects to be applied to an audio clip. You can also reorganize and customize the list. audio lead -- See J-cut. Audio Mixer window -- The Premiere window used to dynamically monitor and control the volume level and pan/balance of multiple audio tracks on the Timeline to combine them into a final program. audio waveform -- A graphical representation of an audio clip, helping to visualize the sound in the clip by showing the signal levels. Premiere can show a waveform in audio tracks in the Timeline and in a separate Clip window when you open an audio clip. AVI -- Acronym for Audio Video Interleave. The old multimedia file format used under Windows for interleaved video and audio streams. See also Video for Windows, Windows Media. - B -balance -- To distribute two channels of a stereo clip between the left and right channels. See also pan. bandpass effects -- Audio effects designed to remove specific frequencies from an audio clip (manifested as hisses, whines, and hums). bandwidth -- The amount and rate of data that can be processed or transmitted by a given device. An analog modem has very little bandwidth compared to a high-speed cable modem, for instance, so the former cannot download video from the Internet nearly as quickly as the latter. See also data rate. baseband video -- See composite video. batch capture -- The automated process of capturing an entire group of clips (such as from a DV camcorder) as defined by a batch list. batch list -- A list of clips with the timecode values for each In and Out point (also called a timecode log) to be used in a batch capture process. See also batch capture, log, timecode. Bin window -- The area of the Premiere Project window used to import and organize folders of source clips. bit -- A binary digit. The fundamental element of computer logic and numbers. Represents one of two values: zero or one, off or on, false or true. See also byte. bit rate -- See data rate. bitstream -- A collection of data, as in video or audio data compressed to a file or transmitted between devices. blue screen -- A specially colored backdrop (typically blue or green) that can be matched with a color key and made transparent so that it can be replaced with another video layer. For example, you can cut out a subject from the blue screen background and composite it into another scene. See also matte, key. BMP -- The standard Windows bitmap still image file format. Bitmap files are not compressed, and are therefore significantly larger than the same image stored in formats such as GIF and JPEG. BNC connector -- A twist-on connector commonly used for higher-end video systems. Used for both analog and digital signals. See also F connector, FireWire connector, RCA connector, S-Video connector. byte -- A data element containing eight bits, or 256 distinct values. Commonly used to store a single text character. Computer data transfer rates are traditionally measured in bits, as in Mb for Megabits (millions of bits, with a lower-case "b"); whereas computer data storage is traditionally measured in bytes, as in MB, for megabytes (millions of bytes, with an upper-case "B"). See also bit, GB, KB, MB. - C -caption -- Title text that labels a scene or identifies a location or person onscreen. capture -- To digitize, or import and convert, video and/or audio into digital format on your computer from external devices, such as a camcorder or VCR. You typically use a special video capture card to input analog video into your computer, and then convert and save it into digital files on your disk. With DV camcorders, you transfer digital data directly into your computer over a FireWire / 1394 interface. See also import. CBR -- Acronym for Constant Bit Rate. A compression scheme in which each unit of input material is always compressed to the same output size. For MPEG-2 video, for example, this means that the compressed data always has the same data rate (that is, bytes per second), even when the input material is very easy to encode. See also VBR. channel -- The subcomponents of a clip. For images, an alpha channel can contain a matte or mask image to key certain regions of the image to be transparent. For audio, the separate left and right channels of a stereo clip. 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. clip -- A short piece of video and/or audio, often containing an individual scene. When creating a video project, you import clip files into bins in your Premiere project, and often trim longer clips into individual scenes. You then edit the clips together on the Timeline to play in sequential order to tell the "story" of your production, with transitions between clips and other added effects. Clip window -- The Premiere window used to view and trim individual clips. See also Monitor window, Source view. codec -- A video or audio compression component that can both compress and decompress (encode and decode) files. Media formats and players, such as Windows Media, RealMedia, and QuickTime have a selection of codecs built in, and can add additional codecs to support new file formats. See also compression. Commands palette -- A small floating window along the right side of the Premiere workspace that contains a list of preset commands. You can customize the palette to define buttons and function keys for fast access to often-used commands. composite -- See superimpose. 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. compress -- To reduce the size of audio or video data through the use of a compression scheme. Also called encode. See also decompress, lossy, and lossless. compressor -- Program by which files are compressed. A compressor that also decompresses files (returns them to their original state) is called a codec. See also compress. crawl -- To scroll a line of title text sideways, left or right across the screen. See also roll. credit -- Title text that identifies the people who contributed to a production. Usually scrolled at the end of a show. crop -- To make an image physically smaller by trimming away one or more edges. This reduces the dimensions of the image, and reduces the size of the computer file. cross-fade -- See fade. cut -- To switch
instantly from one clip to another. A video cut appears suddenly onscreen
without any other kind of transition effect. The cut is the most basic kind of
transition for changing scenes and dropping titles onto the screen. - D -data rate -- The speed at which data is transferred, as in bytes per second. Also called bit rate. For example, the speed to download or stream a video file over the Internet, or the speed at which the file must play from a hard disk. When you create a video or audio file, you can specify the target bit rate at which the file will be played. Also called bit rate. See also bandwidth. decode -- See decompress. decompress -- To process a compressed bitstream and recover the original data (if lossless compression), or an approximation of the original (if lossy compression). Also called decode. See also compress. 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. delay -- An audio effect that provides an echo of a sound after a specified time period. 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. dissolve -- A video transition in which one video clip fades into the next. See also fade, transition. dub -- To duplicate or make a copy of a production, traditionally from one tape (usually a master tape) to another tape. duration -- A length of time. For a clip, the length of time that it will play, determined by its overall length. Or if the clip has been trimmed, the difference in time between its In point and Out point. See also timecode. DV -- A Digital Video tape and compression format for consumer and professional video equipment. The DV compression format is used for DV and Digital-8 camcorders. DV format video and audio can be captured using a FireWire / IEEE 1394 interface and then saved and edited in a video editor. The consumer tape format is more accurately called mini-DV. See also analog media. dynamic range -- The difference between the softest and loudest sounds. Decrease to compress the range and reduce noise, or expand to emphasize volume differences. - E -effect -- The result of processing audio and video clips to enhance, improve, or distort them. See also filter. encode -- See compress. edit line -- The current editing point in the Timeline, as displayed in the Monitor window and used for inserts and deletes. In Premiere, show by a triangle control in the time ruler with a vertical line down through the Timeline tracks. Effect Controls palette -- A small floating window along the right side of the Premiere workspace that lists the current effects applied to an audio or video clip. Used to adjust the order of effects and change effect settings. equalize -- To adjust the tonal quality of an audio clip. As with graphic equalizers found in home or auto audio equipment, an equalize effect can to boost or cut the original signal at different frequency bands. export -- To save your production to a file or to an external video device. Premiere can export both individual clips and entire productions on the Timeline to a variety of disk and Web media file formats. See also import. - F -F connector -- A video connector with a thin center wire typically used for antenna connections and RF signals. See also BNC connector, Firewire connector, RCA connector, RF video, S-Video connector. fade -- A gradual transition from one clip to another. With video, the clip changes from transparent to fully opaque (or vice versa) to fade in or out. With audio, the gain changes between silence and full volume. 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. filter -- A transformation applied to a video or audio clip to enhance it or create a visual or auditory effect. See also effect. FireWire -- A digital data interface standard that provides a high-speed Plug-and-Play interface for personal computers. Used for connecting DV camcorders to computers, as well as to hard disk drives and DVD drives. Supports up to 480Mbps data rate. Also known as IEEE 1394 and Sony iLink. See also USB. FireWire connector -- A roughly rectangular, hot-pluggable connector used for FireWire/IEEE 1394 digital connections, especially digital video signals such as from DV camcorders. The connectors can vary in size: full-size (6-pin) for connecting to a computer or hub, and smaller (4-pin) for connecting to equipment such as DV camcorders. See also BNC connector, DV, F connector, RCA connector, S-Video connector. fps -- Frames per second. See frame rate. 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. See also sample rate. four-point edit -- A method of setting In and Out points to precisely control where and how frames are inserted into a Timeline. In a four-point edit, you set all four In and Out markers, and Premiere displays a warning dialog if the durations do not match. See also three-point edit. freeze frame -- A technique in which a particular frame of video is held onscreen. Sometimes the audio portion of the scene continues playing. - G -gain -- Overall audio output volume. Increase gain to amplify a clip, or decrease gain to attenuate a clip, making it quieter. gamma -- A display setting related to the brightness of the middle tones of an image. You can adjust the gamma of an image to lighten or darken the midtones (the middle-gray levels), without significantly changing the dark and light areas (the shadows and highlights). gang -- To adjust multiple tracks at the same time, as in the Premiere Audio Mixer window. garbage matte -- A mask used in a keying operation to remove a region of a frame that contains unwanted objects. GB -- Gigabytes (billions of bytes). In computer use, a gigabyte actually represents the closest binary power of 2 to a billion, or 1024 cubed. In general use in advertising DVD disc capacity, however, the number of "GB" is actually used to specify a different value, a billion decimal. See also byte, KB, MB. GIF -- Acronym for Graphics Interchange Format. A still image file format commonly used on web pages for simple illustrations and animations. Use the JPEG format for photographic images. gradient -- Gradual change from one color (or intensity level) to another. Gradient colors can also become opaque or transparent, varying in translucency from one side to the other. - H -History palette -- A small floating window along the right side of the Premiere workspace that displays a list of your recent actions during the current working session. Used to undo recent operations and return to a previous state of the project. Hz -- Hertz. A measurement used for audio sampling rate, as in the number of audio samples per second. See also sample rate. - I -IEEE 1394 -- See FireWire. iLink -- See FireWire. import -- To bring media elements into your current working space. Video editors can import video and audio clips, still images, and animated sequences in a variety of formats. You can import both individual clips and folders of clips, and add them to bins in an open Project. See also capture, export. In point -- A placeholder used to mark a specific timecode as the starting point of a segment in a longer sequence. You can use In and Out points to mark a clip to be captured from a source tape, to mark part of a clip to be trimmed, or to mark a portion of the Timeline to be played. See also marker, Out point. Info palette -- A small floating window along the right side of the Premiere workspace that displays information about a selected clip or transition. 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. interpolate -- To automatically create graduated steps between two or more keyframes to create smooth transitions for video, audio, and motion effects. 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. - J -J-cut -- A split edit in which the In point of a clip is adjusted to overlap the preceding clip so that the audio portion of the later clip starts playing before its video as a lead-in to the visual cut. Also called an audio lead. See also L-cut. jog -- To move slowly through a program, as with frame advance or frame reverse VCR controls. Use the Premiere jog tread to step frame by frame through a clip or program to position to a specific frame. See also shuttle. JPEG -- A still image file format developed by the Joint Photographic Experts Group that can compress photographic images into much smaller file sizes while sacrificing only a little image quality. Commonly used for photographs on web pages and in e-mail. See also GIF. - K -kerning -- The spacing between adjacent characters in a text string, as in a title. key -- To specify a region of an image or video clip to be used as a mask for transparency. Used to make part of the scene transparent or semitransparent, and then composite it with other superimposed images or video tracks. The region can be specified using features such as color (a color key) or intensity, or with a separate alpha mask or image matte. See also blue screen, matte. keyframe -- A point along a timeline or path that defines where and how the settings for an effect will change. One or more settings can then be interpolated from keyframe to keyframe to create the appearance of a smoothly change over a series of frames or along a motion path. See also interpolate. - L -L-cut -- A split edit in which the audio Out point of a clip is extended beyond the video Out point, so that the audio cuts after the video and continues playing over the beginning of the next clip. See also J-cut. 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. 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. Line level -- An analog audio connection intended for connecting interconnecting audio equipment, and without the amplification required to connect to speakers. See also Mic. log -- A list of clips in a longer sequence, identified by starting and ending timecodes. Use the Premiere batch log to build a list of clips to be batch captured from a tape. lossless -- Any compression scheme, especially for audio and video data, that uses a nondestructive method that retains all the original information, and therefore does not degrade sound or video quality. lossy -- Any compression scheme, especially for audio and video data, that removes some of the original information in order to significantly reduce the size of the compressed data. Lossy image and audio compression schemes such as JPEG and MP3 try to eliminate information in subtle ways so that the change is barely perceptible, and sound or video quality is not seriously degraded. 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). -- Glossary M- Z -- |
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Digital Video Editing /
Adobe Premiere