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SDTV
Standard-definition television (SDTV; also standard definition or SD) is a television system that uses a resolution that is not considered to be either high or enhanced definition. ''Standard'' refers to offering a similar resolution to the analog broadcast systems used when it was introduced. History and characteristics SDTV originated from the need for a standard to digitize analog TV (defined in BT.601) and is now used for digital TV broadcasts and home appliances such as game consoles and DVD disc players. Digital SDTV broadcast eliminates the ghosting and noisy images associated with analog systems. However, if the reception has interference or is poor, where the error correction cannot compensate one will encounter various other artifacts such as image freezing, stuttering, or dropouts from missing intra-frames or blockiness from missing macroblocks. The audio encoding is the last to suffer a loss due to the lower bandwidth requirements. Standards that suppor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISDB
Integrated Services Digital Broadcasting (ISDB; Japanese: , ''Tōgō dejitaru hōsō sābisu'') is a Japanese broadcasting standard for digital television (DTV) and digital radio. ISDB supersedes both the NTSC-J analog television system and the previously used MUSE Hi-vision analog HDTV system in Japan. An improved version of ISDB-T ( ISDB-T International) will soon replace the NTSC, PAL-M, and PAL-N broadcast standards in South America and the Philippines. Digital Terrestrial Television Broadcasting (DTTB) services using ISDB-T started in Japan in December 2003, and since then, many countries have adopted ISDB over other digital broadcasting standards. A newer and "advanced" version of the ISDB standard (that will eventually allow up to 8K terrestrial broadcasts and 1080p mobile broadcasts via the VVC codec, including HDR and HFR) is currently under development. Countries and territories using ISDB-T Asia * * (officially adopted ISDB-T, started broadcasting in di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-definition Television
High-definition television (HDTV) describes a television or video system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since at least 1933; in more recent times, it refers to the generation following standard-definition television (SDTV). It is the standard video format used in most broadcasts: Terrestrial television, terrestrial broadcast television, cable television, satellite television. Formats HDTV may be transmitted in various formats: * 720p (): 921,600 pixels * 1080i () interlaced scan: 1,036,800 pixels (≈1.04Mpx). * 1080p () progressive scan: 2,073,600 pixels (≈2.07Mpx). ** Some countries also use a non-standard CTA resolution, such as : 777,600 pixels (≈0.78Mpx) per field or 1,555,200 pixels (≈1.56Mpx) per frame When transmitted at two megapixels per frame, HDTV provides about five times as many pixels as SD (standard-definition television). The increased resolution provides for a cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhanced Definition
Enhanced-definition television, or extended-definition television (EDTV) is a Consumer Electronics Association (CEA) marketing shorthand term for certain digital television (DTV) formats and devices. Specifically, this term defines an extension of the standard-definition television (SDTV) format that enables a clearer picture during high-motion scenes compared to previous iterations of SDTV, but not producing images as detailed as high-definition television (HDTV). The term refers to devices capable of displaying 480-line or 576-line signals in progressive scan, commonly referred to as 480p ( NTSC-HQ) and 576p (PAL/SECAM) respectively, as opposed to interlaced scanning, commonly referred to as 480i (NTSC) or 576i (PAL, SECAM). High-motion is optional for EDTV. In Australia, the 576p resolution standard was used by the Special Broadcasting Service (SBS TV) and Seven Network, being technically considered high-definition. In Japan, the term is associated with improvements to anal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nominal Analog Blanking
Nominal analogue blanking is the outermost part of the overscan of a standard definition digital television image. It consists of a gap of black (or nearly black) pixels at the left and right sides, which correspond to the end and start of the horizontal blanking interval: the front porch at the right side (the end of a line, before the sync pulse), and the back porch at the left side (the start of a line, after the sync pulse and before drawing the next line). Digital television ordinarily contains 720 pixels per line, but only 702 (PAL) to 704 (NTSC) of them contain picture content. The location is variable, since analogue equipment may shift the picture sideways in an unexpected amount or direction. The exact width is determined by taking the definition of the time required for an active line in PAL or NTSC, and multiplying it by the pixel clock of 13.5 MHz of Digital SDTV. PAL is exactly 52 μs, so it will equate to exactly 702 pixels. Notably, screen shapes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
480i
480i is the video mode used for standard-definition digital video in the Caribbean, Japan, South Korea, Taiwan, Philippines, Myanmar, Western Sahara, and most of the Americas (with the exception of Argentina, Paraguay, and Uruguay). The other common standard definition digital standard, used in the rest of the world, is 576i. It originated from the need for a standard to digitize analog 525 line TV (defined in BT.601) and is now used for digital TV broadcasts and home appliances such as game consoles and DVD disc players. The ''480'' identifies a vertical resolution of 480 lines, and the ''i'' identifies it as an interlaced resolution. The field rate, which is 60 Hz (or 59.94 Hz when used with NTSC color), is sometimes included when identifying the video mode, i.e. 480i60; another notation, endorsed by both the International Telecommunication Union in BT.601 and SMPTE in SMPTE 259M, includes the frame rate, as in 480i/30. Although related, it should n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiplexing
In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource—a physical transmission medium. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now widely applied in communications. In telephony, George Owen Squier is credited with the development of telephone carrier multiplexing in 1910. The multiplexed signal is transmitted over a communication channel such as a cable. The multiplexing divides the capacity of the communication channel into several logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, extracts the original channels on the receiver end. A device that performs the multiplexing is called a multiplexer (MUX), and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anamorphic Widescreen
Anamorphic widescreen (also called full-height anamorphic or FHA) is a process by which a widescreen image is horizontally compressed to fit into a storage medium (photographic film or MPEG-2 standard-definition frame, for example) with a narrower aspect ratio, reducing the horizontal resolution of the image while keeping its full original vertical resolution. Compatible play-back equipment (a projector with modified lens, or a digital video player or set-top box) can then expand the horizontal dimension to show the original widescreen image. This is typically used to allow one to store widescreen images on a medium that was originally intended for a narrower ratio, while using as much of the frame – and therefore recording as much detail – as possible. The technique comes from cinema, when a film would be framed and recorded as widescreen but the picture would be "squashed together" using a special concave lens to fit into non-widescreen 1.37:1 aspect ratio film. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overscan
Overscan is a behaviour in certain television sets in which part of the input picture is cut off by the visible bounds of the screen. It exists because cathode-ray tube (CRT) television sets from the 1930s to the early 2000s were highly variable in how the video image was positioned within the borders of the screen. It then became common practice to have video signals with black edges around the picture, which the television was meant to discard in this way. Origins Early analog televisions varied in the displayed image because of manufacturing tolerance problems. There were also effects from the early design limitations of power supplies, whose DC voltage was not regulated as well as in later power supplies. This could cause the image size to change with normal variations in the AC line voltage, as well as a process called blooming, where the image size increased slightly when a brighter overall picture was displayed due to the increased electron beam current causing the CRT anod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
576i
576i is a standard-definition television, standard-definition digital video mode, originally used for Digitization, digitizing 625 lines, 625 line Analog television, analogue television in most countries of the world where the utility frequency for electric power distribution is 50 Hz. Because of its close association with the legacy colour encoding systems, it is often referred to as PAL#PAL region, PAL, PAL/SECAM or SECAM when compared to its 60 Hz (typically, see PAL-M) NTSC-colour-encoded counterpart, 480i. The ''576'' identifies a vertical resolution of 576 lines, and the ''i'' identifies it as an Interlaced video, interlaced resolution. The Refresh rate, field rate, which is 50 Hertz, Hz, is sometimes included when identifying the video mode, i.e. 576i50; another notation, endorsed by both the International Telecommunication Union in Rec. 601, BT.601 and SMPTE in SMPTE 259M, includes the frame rate, as in 576i/25. Operation In analogue television, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interlaced
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 characteristics of the human visual system. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Aspect Ratio
A pixel aspect ratio (PAR) is a mathematical ratio that describes how the width of a pixel in a digital image compares to the height of that pixel. Most digital imaging systems display an image as a grid of tiny, square pixels. However, some imaging systems, especially those that must be compatible with standard-definition television motion pictures, display an image as a grid of rectangular pixels, in which the pixel width and height are different. Pixel aspect ratio describes this difference. Use of pixel aspect ratio mostly involves pictures pertaining to standard-definition television and some other exceptional cases. Most other imaging systems, including those that comply with SMPTE standards and practices, use square pixels. PAR is also known as ''sample aspect ratio'' and abbreviated ''SAR'', though it can be confused with storage aspect ratio. Introduction The ratio of the width to the height of an image is known as the aspect ratio, or more precisely the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
