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This page provides a few simple video terms to get you started.

Capture Device: A hardware or firmware device used to convert analogue video into digital video.

Compressors & Codec’s: Software or firmware used to compress and decompress digital video. Compression makes the file size smaller.

Editing: The process of rearranging, adding or removing sections of video clips. Also, creating transitions between clips. Editing is part of post-production.

Encoding: The process of converting digital video into a particular format, for example, saving a video project in MGEG-2 format for DVD distribution.

Layering: Adding multiple layers of superimposed video.

Linear Editing: Also known as tape to tape editing. A method of editing in which footage is copied from one tape to another in the required order.

Non Linear Editing: An editing method which uses computer software to edit the footage.

Transition: The way one shot changes to the next.

Post Production: Everything that happens to the video and audio after production, i.e. after the footage has been shot. Post production includes video editing, audio editing, titling, color correction, effects, etc.

Screen Formats

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.

Video Fundamentals

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.

Audio Fundamentals

Mono: Monophonic audio - a single channel of audio. See also stereo.

Stereo: Two-channel audio, with left and right channels. See also mono, surround sound.

Narration: A voice that explains what is happening on a video. Voiceover narration can add tremendous value to a video by explaining the situation being shown to viewers.

Sample rate: The rate at which samples of a continuous signal, such as music or a sound, are captured into a digital representation of the original signal. A higher audio sampling rate, with more samples per second, creates a more accurate representation of the original sound. See also frame rate, Hz.

Hz: Hertz. A measurement used for audio sampling rate, as in the number of audio samples per second. See also sample rate.

Mic: Microphone audio input. See also Line Level.

Line level: An analog audio connection intended for connecting interconnecting audio equipment, and without the amplification required to connect to speakers. See also Mic.

Analog Video Formats

NTSC: A television video format used in the United States and elsewhere. Displayed 525 lines of resolution at 60 fields per second, 30 frames per second (actually a fractional value near 29.97). Named for the National Television Standards Committee. See also PAL.

PAL: Acronym for Phase Alternation Line. A television video format used in Europe and elsewhere. Displayed with 625 lines of resolution at 50 fields per second, 25 frames per second. See also NTSC.

NTSC safe colors: Colors that are inside the safe region for NTSC television video. Title colors that are outside this range can display badly and bleed on NTSC televisions. See also safe area.

RF video: Acronym for Radio Frequency. A composite video signal that has been modulated with audio onto a high-frequency radio wave that could be transmitted from an antenna. Typically connected to the antenna input of a TV receiver, and received on channel 3 or 4. The simplest and lowest-quality video signal connection. See also component video, composite video, DV, S-Video.

S-Video: A video signal that transmits the brightness (luminance or luma) and the color (chrominance or chroma) information separately. Actually uses a single cable, but with two wires in the cable. Because the luma and chroma are separate, S-Video provides higher quality than composite video. Requires a separate audio signal and connector. Also called Y/C, or sometimes (incorrectly) called S-VHS. See also composite video, component video, DV, RF video.

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.

RCA connector: A connector with a single central plug, commonly used for audio signals and composite and component video. Also called a phono connector. See also BNC connector, F connector, FireWire connector, S-Video connector.

S-Video connector: A specialized connector used for S-Video signals. Contains multiple pins for the separate video components. See also BNC connector, F connector, FireWire connector, RCA connector, S-Video.

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.

Digital Video Formats

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.

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 480 Mbps 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.

USB (Universal Serial Bus): A digital data interface standard providing a Plug-and-Play interface for personal computers. Typically used for lower-speed peripherals such as mice, keyboards, printers, and scanners. Also used for interfacing to digital cameras. The existing USB 1 standard provides up to 12Mbps (million bits per second) data rate. The new USB 2 standard supports up to 480Mbps data rate. See also FireWire.

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.

Video for Windows: The media file format used with Microsoft Windows (.AVI). Supports many different video and audio compression formats (codecs). See also Windows Media.

Windows Media: The multimedia platform built into Microsoft Windows, and a series of formats for storing and transmitting video and audio. Uses ASF, WMA, and WMF file types. See also Video for Windows, Windows Media Audio and Windows Media Video.

Windows Media Video (WMV): The Microsoft Windows Media format for compressed video and audio files on CD and DVD discs. See also Windows Media Audio.

QuickTime: Multiplatform, multimedia Movie file format from Apple Computers (.MOV).

RealMedia: Multiplatform, multimedia Web streaming file format from Real Networks (.RM, .RAM).

Streaming media: Internet video and/or audio clips that can play directly over the Internet, without needing to be downloaded first onto a computer. Used to view and hear broadcasts, and to interactively play and seek in stored clips. See also progressive download.

Progressive download: A technique for downloading Internet video and/or audio clips so that they can be viewed at the same time that they are being transferred to your computer. This provides some of the benefits of streaming media without requiring a special streaming server. See also streaming media.

MPEG: A family of popular multimedia file formats and associated compression schemes defined by the Moving Pictures Expert Group. MPEG-1 video was designed for use on CD-ROMs and provides picture quality somewhat comparable to VHS. MPEG-2 video was designed for consumer video and is used on DVD, and can provide high-quality full-screen full-rate video with smaller file sizes. MPEG-4 video is designed for a broad range of multimedia applications, and is used for web and wireless streaming video. MP3 is a commonly-used audio compression format, especially for web downloads and portable music players.

MPEG-1: An older digital video compression format developed in the early 1990s by the Moving Picture Experts Group. MPEG-1 video was designed for lower-resolution video played from CD-ROM and provides picture quality somewhat comparable to VHS (typically 352x240 resolution). Used for Video CD discs.

MPEG-2: A TV-quality digital video compression format developed in the mid-1990s by the Moving Picture Experts Group. MPEG-2 video provides high-quality full-screen full-rate video (720x480 resolution for NTSC) with smaller file sizes than MPEG-1. Used for DVD discs, and also scales to high-definition resolution and bitrates.

MPEG-4: A digital multimedia compression format developed in the late 1990s by the Moving Picture Experts Group, that includes video, audio, and interactivity. MPEG-4 video is designed for interactive multimedia across networks, and works well for web and wireless streaming video.

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.

VBR: Acronym for Variable Bit Rate. A compression scheme in which each unit of input material can be compressed to different sizes. For MPEG-2 video, for example, this means that "easier" sequences (that is, with no motion) can compress to very small sizes, whereas "hard" sequences (with lots of motion and scene cuts) can compress to much larger sizes. VBR compression can take better advantage of the overall available bandwidth of a video transmission or DVD player by allocating the available bits intelligently to the difficult parts of a sequence. See also CBR.

HDV: HD on DV - MPEG-2 video in HD resolution.

AVCHD: MPEG-4 AVC in HD

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