|
XFree86 Modeline
: ''A mode line may also refer to a line for the Emacs and Vim editors that provides information about the file and modes.'' A modeline is a configuration line in xorg.conf or the XFree86 configuration file (XF86Config) that provides information to the display server about a connected computer monitor or television and how to drive it at a specified display resolution. The Modeline is based on the Generalized Timing Formula or the Coordinated Video Timings standards produced by VESA. Modelines are now rarely used, but XFree86 and the Xorg Server still allow them to be set should the EDID information be inadequate. Syntax Each modeline has ten parameters, beginning with a label for the resolution being specified. The second parameter specifies the rate of the pixel clock in megahertz. Then follow four numbers that together specify the ''x''-resolution (width) and related parameters, and four numbers that specify the ''y''-resolution (height). * Modeline syntax: * Flags (optio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emacs
Emacs , originally named EMACS (an acronym for "Editor MACroS"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, self-documenting, real-time display editor". Development of the first Emacs began in the mid-1970s, and work on its direct descendant, GNU Emacs, continues actively; the latest version is 28.2, released in September 2022. Emacs has over 10,000 built-in commands and its user interface allows the user to combine these commands into macros to automate work. Implementations of Emacs typically feature a dialect of the Lisp programming language, allowing users and developers to write new commands and applications for the editor. Extensions have been written to, among other things, manage files, remote access, e-mail, outlines, multimedia, git integration, and RSS feeds, as well as implementations of ''ELIZA'', ''Pong'', '' Conway's Life'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EDID
Extended Display Identification Data (EDID) and Enhanced EDID (E-EDID) are metadata formats for display devices to describe their capabilities to a video source (e.g. graphics card or set-top box). The data format is defined by a standard published by the Video Electronics Standards Association (VESA). The EDID data structure includes manufacturer name and serial number, product type, phosphor or filter type (as chromaticity data), timings supported by the display, display size, luminance data and (for digital displays only) pixel mapping data. DisplayID is a VESA standard targeted to replace EDID and E-EDID extensions with a uniform format suited for both PC monitor and consumer electronics devices. Background EDID structure (base block) versions range from v1.0 to v1.4; all these define upwards-compatible 128-byte structures. Version 2.0 defined a new 256-byte structure but it has been deprecated and replaced by E-EDID which supports multiple extension blocks. HDMI versions 1.0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raster Scan
A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems. The word ''wiktionary:raster, raster'' comes from the Latin word ''wiktionary:rastrum, rastrum'' (a rake), which is derived from ''wiktionary:radere, radere'' (to scrape); see also rastrum, an instrument for drawing musical staff lines. The pattern left by the lines of a rake, when drawn straight, resembles the parallel lines of a raster: this line-by-line scanning is what creates a raster. It is a systematic process of covering the area progressively, one line at a time. Although often a great deal faster, it is similar in the most general sense to how one's gaze travels when one reads lines of text. The data to be drawn is stored in an area of memory called the Framebuffer. This memory area holds the values for each pixel on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HDTV
High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the generation following standard-definition television (SDTV), often abbreviated to HDTV or HD-TV. It is the current de facto standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television and Blu-ray Discs. Formats HDTV may be transmitted in various formats: * 720p (1280 horizontal pixels × 720 lines): 921,600 pixels * 1080i (1920×1080) interlaced scan: 1,036,800 pixels (~1.04 MP). * 1080p (1920×1080) progressive scan: 2,073,600 pixels (~2.07 MP). ** Some countries also use a non-standard CEA resolution, such as 1440×1080i: 777,600 pixels (~0.78 MP) per field or 1,555,200 pixels (~1.56 MP) per frame When transmitted at two megapixels per frame, HDTV provides about five times a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Scan
A flicker fixer or scan doubler is a piece of computer hardware that de-interlaces an output video signal. The flicker fixer accomplishes this by adjusting the timing of the natively interlaced video signal to suit the needs of a progressive display Ex: CRT computer monitor. Flicker fixers in essence create a progressive frame of video from two interlaced fields of video. Flicker fixers sample the NTSC/PAL output from the output device and store each scan line from the field currently being displayed in RAM while simultaneously outputting the line alternately with the corresponding neighboring lines from the field stored previously (''weaving''). Some more advanced flicker fixers integrated in add-on graphics cards use more sophisticated methods. Outputting the image at double scan rate essentially composes a progressive display with all lines from both fields at full vertical refresh rate. This promotes the horizontal frequency of the signal from 15.734 kHz to 31.47&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interlaced Video
Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. This enhances motion perception to the viewer, and reduces flicker by taking advantage of the phi phenomenon. This effectively doubles the time resolution (also called ''temporal resolution'') as compared to non-interlaced footage (for frame rates equal to field rates). Interlaced signals require a display that is natively capable of showing the individual fields in a sequential order. CRT displays and ALiS plasma displays are made for displaying interlaced signals. Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the other being progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all od ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one hertz is the reciprocal of one second. It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon, via the Planck relation ''E'' = ''hν'', where ''E'' is the photon's energy, ''ν'' is its freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refresh Rate
The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tubes) is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate, which describes how many images are stored or generated every second by the device driving the display. On cathode ray tube (CRT) displays, higher refresh rates produce less flickering, thereby reducing eye strain. In other technologies such as liquid-crystal displays, the refresh rate affects only how often the image can potentially be updated. Non-raster displays may not have a characteristic refresh rate. Vector displays, for instance, do not trace the entire screen, only the actual lines comprising the displayed image, so refresh speed may differ by the size and complexity of the image data. For computer programs or telemetry, the term is sometimes applied to how frequently a datum is updated with a new external value from anothe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sync Pulse
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television. All broadcast television systems used analog signals before the arrival of DTV. Motivated by the lower bandwidth requirements of compressed digital signals, beginning in the 2000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Television
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, instantaneous phase and frequency, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that Noise (electronics), electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes Noise (video), snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below digital cliff, a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television. All broadcast television systems used analog signals before the arrival of DTV. Motivated by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megahertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one hertz is the reciprocal of one second. It is named after Heinrich Hertz, Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in metric prefix, multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the photon energy, energy of a photon, via the Planck relation ''E'' = ''hν'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Clock
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a sample of an original image; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''sensel'' is sometimes used), while in yet other contexts (like MRI) it may refer to a set of component intensities for a spatial position. Etymology The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
