VGA to TV conversion glossary
- Active display area: The area on the face of the CRT that the image is displayed on.
- Animation: The drawing (either electronically or on a physical medium) of motion. Usually animation is completed in a frame-by-frame process.
- Bandwidth: For monitors, bandwidth refers to the highest signal frequency a monitor's circuit can display. The higher the bandwidth, the higher the resolution and the sharper the image will be.
- Composite video: A video stream that combines red, green, blue, and synchronization signals into one so that it requires only one connector and/or connection. Composite video is employed by most television systems (e.g., NTSC, PAL) and VCRs.
- Composite Video Output: The monitor receives only one signal from the computer. The monitor must then decode the signal to determine and separate red, green, blue and sync signals that can then be processed by the monitor.
- Compression: Reduction in the number of bits used to represent an item of data.
- Decoding (video capture): The process of converting TV interlaced video to noninterlaced RGB video.
- Dot Pitch: The distance of one phosphor dot to the nearest phosphor dot of the same color on the adjacent line.
- Electronic Guns: The device in the CRT that produces the electron beam that is attracted to the phosphors on the face of the CRT; this activates the phosphors thus causing them to emit red, green or blue light.
- Field (of video): Each frame of video in the PAL or NTSC signal consists of two fields. Television creates a picture through vertical lines, each field has 262.5 (in NTSC) or 312.5 (in PAL) lines of video. The lines are displayed on the television tube in an interlace pattern. The odd lines of each frame are scanned, producing one field, then the even lines are scanned, producing the other field. Together, the two fields create a frame.
- Frame(of video): A frame of video consists of two fields. Each second of NTSC video consists of 29.97 frames (usually rounded off to 30 frames a second). Each second of PAL video consists of 25 frames.
- Frequency Range: The high end and low limits of the frequencies that can be used with your monitor. Usually pertains to horizontal and vertical sync ranges.
- Full-Scan: The capability to increase the size of the image to the edge of the monitor bezel.
- Genlock: A feature that keeps two or more video streams in synchronization, often combined with a graphic overlay capability. hardware periphral that allows the user to combine computer graphics on top of an external video signal is also sometimes called genlock.
- Graphic Overlay, titling: The superimposition of a computer image over a video signal (the computer image typically is keyed to replace a given color or color range in the TV signal).
- Glitches: Any oddity in a video signal.
- Horizontal Frequency: The inverse of the time it takes for a monitor to scan from the beginning of one line to the beginning of the next line; typically stated in kilohertz.
- Horizonal sync frequency: the number of times per the number of times per electron beam can trace a pattern like this
_______________________ | | |->->->->->->->->->->-> | | )| |<-----<-----<-----<--- | | | | | | | | | |_______________________| - Industry standard: A term applied to a machine or format that is commonly used within a certain area of production.
- Interlace: The method of presenting a video display a half picture at a time, showing only every other line at a time. PAL and NTSC video standards for television employs an interlaced signal.
- Interlaced: Every other line is scanned during each total vertical (full) screen refresh.
- Interlaced video: TV frames consist of two fields of alternating lines that are scanned onto the picture display unit (e.g., picture tube) in rapid sequence to produce an interlaced video image.
- Multiscan Monitor: Monitors that are capable of displaying a range of resolutions or graphics standards having different horizontal and vertical frequencies.
- Noninterlaced video: Each line is scanned during each total vertical (full) screen refresh. Computer monitors use typically noninterlaced video.
- National Television System Committee (NTSC): Standards-setting body which has set the TV standards for North America. Specifically for traditional TV, it specifies a 525-line, 30-frames-per-second format. Video conforming to this standard is typically also referred to as NTSC.
- NTSC: Abbreviation for National Television System Committee, color TV system used in USA
- Overscan: The TV approach of bleeding the video signal off the edges of the picture display unit. When converting computer screen to overscan, graphics and text at the edges of the image may be lost. Vertical overscan means that a few lines will go off the visible edges of the TV screen resulting in either the top or bottom of the image being cut off.�Horizonal overscan means that some parts of the picture on left and right sides may be cut off because they don't fit to visible TV screen.
- Phase Alternate Line (PAL): The video format standard used in Europe. It employs 625 lines per frame and displays 25 frames per second (this results in more flicker compared to NTSC video).
- Phosphor: Phosphorescent substance of red, green and blue that emit light when activated by electrons.
- Pixel: A definable location on a display screen that consists of multiple or single triad of dots (red, green and blue).
- Raster: The overall area that is scanned by the electron guns.
- Refresh: One vertical scan.
- Resolution: The number of dots (consisting of one or more pixels) displayed on the screen; typically stated in number of dots per line by number of lines; the higher the resolution, the greater the amount of detail that can be displayed or the sharper the image; if standard, a resolution will be called a graphics standard.
- RGB: Red, Green, and Blue are the three additive colors used for TV and computer monitor signals.
- RGB Video Output: The monitor receives red, green and blue signals separately from the computer.
- S-video: A video signal that employs two channels: luminance (Y; namely brightness) and chrominance (C; namely color). It is referred to as Y/C. It falls between component and composite video in terms of quality.
- SECAM (Sequential Color and Memory): TV system used in France and Russia (the chrominance is frequency modulated).
- Super VGA: A graphics standard of 800 dots by 600 lines (or more resolution); this standard has versions with different vertical frequencies.
- PAL: short for Phase Alternate Line, color TV system used in most of Europe
- Super VGA: a common name for new PC graphics cards which are compatible with original VGA card but provide better resolutions and more colors. There is no standard how the hardware for those higher resolution graphics modes should be implemented which means that that the software and/or operating system must have graphics card specific driver to be able to use those higher resolutions. For DOS software VESA VGA BIOS Extension is a standard software interface for accessing those higher resolutions.
- SCART: standard AV-connector used in AV equipments designed for European markets almost almost every modern TV in Europe has this connector. This 21 pin connector can carry composite video, RGB, audio and some control signals all in one connector.
- Time base corrector (TBC): A TBC synchronizes video signals, allowing the signals to be locked into switcher timing.
- Underscan: The picture content does not fill the whole picture tube area which means that there are borders around the visible picture area.
- VCR: video recorder
- Vertical sync frequency: the number of times per the number of times per electron beam can trace a pattern like this
_______________________ | ^ | | ^ | | | | v | | ^ | | | | | | | ^ | | | | v | | ^ | | |_______|_v_____________| - VESA VGA BIOS Extension: A standard software interface for DOS programs (mostly games) to access higher than standard VGA resolutions in PC graphics cards.
- VGA: Computer graphics card designed by IBM which has become de-facto standard in PC industry. Almost all PC graphics cards sold today are are more or less compatible with the original IBM Video Graphics Array (VGA) card. IBM's Video Graphics Array includes the following resolutions: 320x200, 640x200, 640x480, 320x400, 640x350, 720x350, 360x400, 640x400 and 720x400
- VHS: A popular home-use half-inch format. Not suitable for reproducing video for broadcast use.
- Video Connector: The connector on the video card or computer's graphics output that the monitor cable is connected to.
- Waveform monitor: An oscilloscope that measures the white and chroma levels of videotape or other video source
- YUV: The color space used by PAL and some NTSC formats (Y is the luminance and U and V are the color components).
- XGA: Extended Graphics Adapter; IBM's graphics standard that includes VGA and extended resolutions up to 1024 pixels by 768 lines interlaced and non-interlaced resolution.