MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods, which permit storage and transmission of movies using currently available storage media and transmission bandwidth. While MPEG-2 is not as efficient as newer standards such as H.264/AVC and H.265/HEVC, backwards compatibility with existing hardware and software means it is still widely used, for example in over-the-air digital television broadcasting and in the DVD-Video standard.
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I or K. The articles on analog broadcast television systems further describe frame rates, image resolution, and audio modulation.
Standard-definition television is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing specification for broadcast television in the mid- to late-20th century, and compatible with legacy analog broadcast systems.
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems which, in turn, were replaced by flat panel displays of several types.
ITU-R Recommendation BT.601, more commonly known by the abbreviations Rec. 601 or BT.601 is a standard originally issued in 1982 by the CCIR for encoding interlaced analog video signals in digital video form. It includes methods of encoding 525-line 60 Hz and 625-line 50 Hz signals, both with an active region covering 720 luminance samples and 360 chrominance samples per line. The color encoding system is known as YCbCr 4:2:2.
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).
Anamorphic widescreen is a process by which a comparatively wide widescreen image is horizontally compressed to fit into a storage medium with a narrower aspect ratio, reducing the horizontal resolution of the image while keeping its full original vertical resolution. Compatible play-back equipment 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 display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode ray tube (CRT) displays, flat-panel displays and projection displays using fixed picture-element (pixel) arrays.
PALplus is an analogue television broadcasting system aimed to improve and enhance the PAL format by allowing 16:9 aspect ratio broadcasts, while remaining compatible with existing television receivers, defined by ITU recommendation BT.1197-1. Introduced in 1993, it followed experiences with the HD-MAC and D2-MAC, hybrid analogue-digital widescreen formats that were incompatible with PAL receivers. It was developed at the University of Dortmund in Germany, in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. The system had some adoption across Europe during the late 1990s and helped introduce widescreen TVs in the market, but never became mainstream.
HD-MAC was a broadcast television standard proposed by the European Commission in 1986, as part of Eureka 95 project. It belongs to the MAC - Multiplexed Analogue Components standard family. It is an early attempt by the EEC to provide High-definition television (HDTV) in Europe. It is a complex mix of analogue signal, multiplexed with digital sound, and assistance data for decoding (DATV). The video signal was encoded with a modified D2-MAC encoder.
480p is the shorthand name for a family of video display resolutions. The p stands for progressive scan, i.e. non-interlaced. The 480 denotes a vertical resolution of 480 pixels, usually with a horizontal resolution of 640 pixels and 4:3 aspect ratio or a horizontal resolution of 854 or less pixels for an approximate 16:9 aspect ratio. Since a pixel count must be a whole number, in Wide VGA displays it is generally rounded up to 854 to ensure inclusion of the entire image. The frames are displayed progressively as opposed to interlaced. 480p was used for many early plasma televisions. Standard definition has always been a 4:3 aspect ratio with a pixel resolution of 720 × 480 at 60 Hz for NTSC regions, and 720 or 768 × 576 for PAL regions. However, standard definition defines a 15.7k Hz horizontal scanrate, which means that interlacing has to be used for those resolution modes. The lowercase letter "p" in 480p stands for progressive, so the two must not be confused.
1080i is a combination of frame resolution and scan type. 1080i is used in high-definition television (HDTV) and high-definition video. The number "1080" refers to the number of horizontal lines on the screen. The "i" is an abbreviation for "interlaced"; this indicates that only the even lines, then the odd lines of each frame are drawn alternately, so that only half the number of actual image frames are used to produce video. A related display resolution is 1080p, which also has 1080 lines of resolution; the "p" refers to progressive scan, which indicates that the lines of resolution for each frame are "drawn" on the screen in sequence.
480i is the video mode used for standard-definition digital television in the Caribbean, Japan, South Korea, Taiwan, Philippines, Laos, Western Sahara, and most of the Americas. 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, 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. 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 TV and is now used for digital TV broadcasts and home appliances such as game consoles and DVD disc players.
Image resolution is the detail an image holds. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail.
576i is a standard-definition digital video mode, originally used for digitizing analog 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 color encoding systems, it is often referred to as PAL, PAL/SECAM or SECAM when compared to its 60 Hz NTSC-colour-encoded counterpart, 480i.
576p is the shorthand name for a video display resolution. The p stands for progressive scan, i.e. non-interlaced, the 576 for a vertical resolution of 576 pixels. Usually it corresponds to a digital video mode with a 4:3 anamorphic resolution of 720x576 and a frame rate of 25 frames per second (576p25), and thus using the same bandwidth and carrying the same amount of pixel data as 576i, but other resolutions and frame rates are possible.
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.
Pixel aspect ratio is a mathematical ratio that describes how the width of a pixel in a digital image compares to the height of that pixel.
High-definition television 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.
Ultrawide formats refers to photos, videos, and displays with aspect ratios greater than 2. There were multiple moves in history towards wider formats, including one by Disney, with some of them being more successful than others.
