High-definition television (or HDTV, or just HD) refers to video having resolution Image resolution describes the detail an image holds. The term applies to digital images, film images, and other types of images. Higher resolution means more image detail substantially higher than traditional television systems (standard-definition TV, or SDTV, or SD Standard-definition television is a television system that has a resolution that meets standards but not considered either or neither enhanced-definition television (EDTV) or high-definition television (HDTV). The term is usually used in reference to digital television, in particular when broadcasting at the same (or similar) resolution as analog). HD has one or two million pixels per frame, roughly five times that of SD. Early HDTV broadcasting used analog techniques, but today HDTV is digitally Digital television is the transmission of audio and video by discrete (digital) signals, in contrast to the analog signals used by analog TV. It is gradually replacing analog TV, and has done so in several industrialized nations, including the United States and Germany broadcast Broadcasting is the distribution of audio and/or video signals which transmit programs to an audience. Receiving parties may include the general public or a relatively large subset of the whole, such as children or young adults using video compression Video compression refers to reducing the quantity of data used to represent digital video images, and is a combination of spatial image compression and temporal motion compensation. Video compression is an example of the concept of source coding in Information theory. This article deals with its applications: compressed video can effectively.

Projection screen A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. Projection screens may be permanently installed as in a movie theater, painted on the wall, semi-permanent or mobile, as in a conference room or other non-dedicated viewing space. Uniformly white in a home theater Home cinema, also commonly called home theater, are home entertainment set-ups that seek to reproduce the movie theater going experience and mood with the help of video and audio equipment in a private home, displaying an HDTV image.

Contents

History of high-definition television

Further information: Analog high-definition television system Historically the term high-definition television was first used to refer to television standards developed in the 1930s to replace early experimental systems with as few as 12 lines. Not long afterwards John Logie Baird, Philo T. Farnsworth and Vladimir Zworykin had each developed competing TV systems, but resolution was not the issue that

The term high definition once described a series of television systems originating from the late 1930s; however, these systems were only high definition when compared to earlier systems that were based on mechanical systems with as few as 30 lines of resolution.

The British high definition TV service started trials in August 1936 and a regular service in November 1936 using both the (mechanical) Baird 240 line and (electronic) Marconi-EMI 405 line The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting (377i) systems. The Baird system was discontinued in February 1937. In 1938 France followed with their own 441 line system, variants of which were also used by a number of other countries. The US NTSC NTSC, named for the National Television System Committee, is the analog television system used in most of North America, most countries in South America, Burma, South Korea, Taiwan, Japan, Philippines, and some Pacific island nations and territories . NTSC is also the name of the U.S. standardization body that developed the broadcast standard. The system joined in 1941. In 1949 France introduced an even higher resolution standard at 819 lines Historically the term high-definition television was first used to refer to television standards developed in the 1930s to replace early experimental systems with as few as 12 lines. Not long afterwards John Logie Baird, Philo T. Farnsworth and Vladimir Zworykin had each developed competing TV systems, but resolution was not the issue that (768i), a system that would be high definition even by today's standards, but it was monochrome only. All of these systems used interlacing and a 4:3 aspect ratio The aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this same length unit, the height will be measured to be y except the 240 line system which was progressive (actually described at the time by the technically correct term of 'sequential') and the 405 line system which started as 5:4 and later changed to 4:3. The 405 line system adopted the (at that time) revolutionary idea of interlaced scanning to overcome the flicker problem of the 240 line with its 25 Hz frame rate. The 240 line system could have doubled its frame rate but this would have meant that the transmitted signal would have doubled in bandwidth, an unacceptable option.

Color broadcasts started at similarly higher resolutions, first with the US NTSC color system in 1953, which was compatible with the earlier B&W systems and therefore had the same 525 lines (480i) of resolution. European standards did not follow until the 1960s, when the PAL PAL, short for Phase Alternate Line, is an analogue television encoding system used in broadcast television systems in large parts of the world. Other common analogue television systems are SECAM and NTSC. This page primarily discusses the colour encoding system. See the articles on broadcast television systems and analogue television for and SECAM SECAM, also written SÉCAM , is an analog color television system first used in France. A team led by Henri de France working at Compagnie Française de Télévision (later bought by Thomson) invented SECAM. It is, historically, the first European color television standard colour systems were added to the monochrome 625 line (576i) broadcasts.

Since the formal adoption of Digital Video Broadcasting Digital Video Broadcasting is a suite of internationally accepted open standards for digital television. DVB standards are maintained by the DVB Project, an international industry consortium with more than 270 members, and they are published by a Joint Technical Committee (JTC) of European Telecommunications Standards Institute (ETSI), European's (DVB) widescreen HDTV transmission modes in the early 2000s the 525-line NTSC NTSC, named for the National Television System Committee, is the analog television system used in most of North America, most countries in South America, Burma, South Korea, Taiwan, Japan, Philippines, and some Pacific island nations and territories . NTSC is also the name of the U.S. standardization body that developed the broadcast standard. The (and PAL-M PAL-M is the TV system used in Brazil since February 19, 1972. At that time, Brazil was the first South American country to broadcast in color. Color TV broadcast began on September 1972 when the TV networks Globo, Tupi and Bandeirantes TV transmitted the Caxias do Sul Grape Festival. Transition from black and white to color was not complete until) systems as well as the European 625-line PAL PAL, short for Phase Alternate Line, is an analogue television encoding system used in broadcast television systems in large parts of the world. Other common analogue television systems are SECAM and NTSC. This page primarily discusses the colour encoding system. See the articles on broadcast television systems and analogue television for and SECAM SECAM, also written SÉCAM , is an analog color television system first used in France. A team led by Henri de France working at Compagnie Française de Télévision (later bought by Thomson) invented SECAM. It is, historically, the first European color television standard systems are now regarded as standard definition television systems. In Australia, the 625-line digital progressive system (with 576 active lines) is officially recognized as high definition.[1]

Analog systems

In 1949, France started its transmissions with an 819 lines system (768i). It was monochrome only, it was used only on VHF for the first French TV channel, and it was discontinued in 1985.

In 1958, the Soviet Union The Union of Soviet Socialist Republics was a constitutionally socialist state that existed in Eurasia from 1922 to 1991. The name is a translation of the Russian: Союз Советских Социалистических Республик (help·info), tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik, IPA [sɐˈjʊs sɐˈvʲeʦkʲɪx səʦɪ developed Тransformator (Russian Russian is the most geographically widespread language of Eurasia, the most widely spoken of the Slavic languages, and the largest native language in Europe. Russian belongs to the family of Indo-European languages and is one of three living members of the East Slavic languages. Written examples of Old East Slavonic are attested from the 10th: Трансформатор, Transformer), the first high-resolution (definition) television system capable of producing an image composed of 1,125 lines of resolution aimed at providing teleconferencing for military command. It was a research project and the system was never deployed in the military or broadcasting.[2]

In 1969, the Japanese state broadcaster NHK first developed consumer high-definition television with a 5:3 aspect ratio, a slightly wider screen format than the usual 4:3 standard.[3] The system, known as Hi-Vision or MUSE after its Multiple sub-Nyquist sampling encoding for encoding the signal, required about twice the bandwidth of the existing NTSC system but provided about four times the resolution (1080i/1125 lines). Satellite test broadcasts started in 1989, with regular testing starting in 1991 and regular broadcasting of BS The 350 kg BSE was followed in 1984 and 1986 by the operational and essentially identical BS-2a and BS-2b, respectively. Each spacecraft carried two active and one spare 100 W. 14/12 GHz transponders. Built by Toshiba with assistance from General Electric, the BS-2 series were designed for five years of operations. BS-2a was moved to a graveyard-9ch commenced on 25 November 1994, which featured commercial and NHK programming.

In 1981, the MUSE system was demonstrated for the first time in the United States. It had the same 5:3 aspect ratio as the Japanese system.[4] Upon visiting a demonstration of MUSE in Washington, US President Ronald Reagan Ronald Wilson Reagan was the 40th President of the United States (1981–1989) and the 33rd Governor of California (1967–1975). Born in Tampico, Illinois, Reagan moved to Los Angeles, California in 1937. He began a career as an actor, first in films and later television, appearing in 52 movie productions and gaining enough success to become a was most impressed and officially declared it "a matter of national interest" to introduce HDTV to the USA.[5]

Several systems were proposed as the new standard for the USA, including the Japanese MUSE system, but all were rejected by the FCC because of their higher bandwidth requirements. At the same time that the high definition systems were being studied, the number of television channels was growing rapidly and bandwidth was already a problem. A new standard had to be radically efficient, needing less bandwidth for HDTV than the existing NTSC .

Rise of digital compression

Since 1972, International Telecommunication Union The International Telecommunication Union is the eldest organization in the UN family still in existence. It was founded as the International Telegraph Union in Paris on 17 May 1865 and is today the leading United Nations agency for information and communication technology issues, and the global focal point for governments and the private sector's radio telecommunications sector (ITU-R The ITU Radiocommunication Sector is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communication) ITU-R has been working on creating a global recommendation for Analogue HDTV. These recommendations however did not fit in the broadcasting bands which could reach home users. The standardization of MPEG-1 MPEG-1 is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to 1.5 Mbit/s without excessive quality loss, making video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) possible in 1993 also led to the acceptance of recommendations ITU-R BT.709[6]. In anticipation of these standards the DVB organisation was formed, an alliance of broadcasters, consumer electronics manufacturers and regulatory bodies. The DVB develops and agrees on specifications which are formally standardised by ETSI[7].

DVB created first the standard for DVB-S DVB-S is the original Digital Video Broadcasting forward error coding and modulation standard for satellite television and dates from 1994, in its first release, while development lasted from 1993 to 1997. The first application was commercially available in France via Canal+, enabling digitally broadcast, satellite-delivered television to the digital satellite TV, DVB-C DVB-C stands for Digital Video Broadcasting - Cable and it is the DVB European consortium standard for the broadcast transmission of digital television over cable. This system transmits an MPEG-2 or MPEG-4 family digital audio/video stream, using a QAM modulation with channel coding digital cable TV and DVB-T DVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first broadcast in the UK in 1997. This system transmits compressed digital audio, video and other data in an MPEG transport stream, using coded digital terrestrial TV. These broadcasting systems can be used for both SDTV and HDTV. In the USA the Grand Alliance proposed ATSC ATSC is a set of standards developed by the Advanced Television Systems Committee for digital television transmission that replaced much of the analog NTSC television system on June 12, 2009 in the United States and will replace NTSC by August 31, 2011 in Canada and December 31, 2021 in Mexico as the new standard for SDTV and HDTV. Both ATSC and DVB were based on the MPEG-2 standard. The DVB-S2 Digital Video Broadcasting - Satellite - Second Generation is designed as a successor for the popular DVB-S digital television broadcast standard, and was developed in 2003 and ratified by ETSI (EN 302307) in March 2005. It is based on DVB-S and the DVB-DSNG (Digital Satellite News Gathering) standard, used by mobile units for sending external standard is based on the newer and more efficient H.264/MPEG-4 AVC H.264/AVC/MPEG-4 Part 10 is a standard for video compression. The final drafting work on the first version of the standard was completed in May 2003 compression standards. Common for all DVB standards is the use of highly efficient modulation techniques for further reducing bandwidth, and foremost for reducing receiver-hardware and antenna requirements.

In 1983, the International Telecommunication Union The International Telecommunication Union is the eldest organization in the UN family still in existence. It was founded as the International Telegraph Union in Paris on 17 May 1865 and is today the leading United Nations agency for information and communication technology issues, and the global focal point for governments and the private sector's radio telecommunications sector (ITU-R The ITU Radiocommunication Sector is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communication) set up a working party (IWP11/6) with the aim of setting a single international HDTV standard. One of the thornier issues concerned a suitable frame/field refresh rate, with the world already strongly demarcated into two camps, 25/50Hz and 30/60Hz, related by reasons of picture stability to the frequency of their main electrical supplies.

The IWP11/6 working party considered many views and through the 1980s served to encourage development in a number of video digital processing areas, not least conversion between the two main frame/field rates using motion vectors, which led to further developments in other areas. While a comprehensive HDTV standard was not in the end established, agreement on the aspect ratio was achieved.

Initially the existing 5:3 aspect ratio had been the main candidate, but due to the influence of widescreen cinema, the aspect ratio 16:9 (1.78) eventually emerged as being a reasonable compromise between 5:3 (1.67) and the common 1.85 widescreen cinema format. (Bob Morris explained that the 16:9 ratio was chosen as being the geometric mean of 4:3, Academy ratio The Academy ratio of 1.375:1 is an aspect ratio of a frame of 35mm film when used with 4-perf pulldown. It was standardized by the Academy of Motion Picture Arts and Sciences as the standard film aspect ratio in 1932, although similar-sized ratios were used as early as 1928, and 2.35:1, the widest cinema format in common use, in order to minimize wasted screen space when displaying content with a variety of aspect ratios.[8])

An aspect ratio of 16:9 was duly agreed at the first meeting of the IWP11/6 working party at the BBC The British Broadcasting Corporation is the largest broadcasting organisation in the world. Its global headquarters are located in London and its main responsibility is to provide public service broadcasting in the United Kingdom, Channel Islands and Isle of Man. The BBC is an autonomous public service broadcaster that operates under a Royal's Research and Development BBC Research, formerly the BBC Research Department or BBC Research & Development, made major contributions to broadcast technology, carrying out original research in many areas, and developing items like the peak programme meter which became the basis for many world standards establishment in Kingswood Warren. The resulting ITU-R Recommendation ITU-R BT.709-2 ("Rec. 709") includes the 16:9 aspect ratio, a specified colorimetry Colorimetry is "the science and technology used to quantify and describe physically the human color perception." It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space tristimulus values and related quantities, and the scan modes 1080i 1080i is the shorthand name for a format of high-definition video modes. 1080 denotes the number of horizontal scan lines—also known as vertical resolution—and the letter i stands for interlaced. In the alternate format of high-definition video mode, known as 1080p, the p would stand for progressive scan. With interlaced video, two fields (1,080 actively interlaced Interlace is a technique of improving the picture quality of a video signal without consuming extra bandwidth. Interlaced video was designed for display on CRT televisions lines of resolution) and 1080p 1080p is the shorthand identification for a category of HDTV video modes. The number 1080 represents 1,080 lines of vertical resolution , while the letter p stands for progressive scan (meaning the image is not interlaced). The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels. This creates a (1,080 progressively scanned Progressive or noninterlaced scanning is a method for displaying, storing or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to the interlacing used in traditional television systems where only the odd lines, then the even lines of each frame are drawn alternately lines). The current Freeview HD DTV Services, trading as Freeview, is the name for the collection of Free to air services on the Digital Terrestrial Television platform in the UK. The service is jointly run by its five equal shareholders - BBC, ITV, Channel 4, Sky and transmitter operator Arqiva. DTV Services is designed to market changes to the platform. In association with the trials use MBAFF, which contains both progressive and interlaced content in the same encoding.

It also includes the alternative 1440×1152 HDMAC scan format. (According to some reports, a mooted 750 line (720p) format (720 progressively scanned lines) was viewed by some at the ITU as an enhanced television format rather than a true HDTV format,[9] and so was not included, although 1920×1080i and 1280×720p 720p is the shorthand name for a category of HDTV video modes having a resolution of 1280×720 and a progressive scan. The number 720 stands for the 720 horizontal scan lines of display resolution , while the letter p stands for progressive scan or non-interlaced. When broadcast at 60 frames per second, 720p features the highest temporal (motion) systems for a range of frame and field rates were defined by several US SMPTE The Society of Motion Picture and Television Engineers or SMPTE, , founded in 1916 as the Society of Motion Picture Engineers or SMPE, is an international professional association, based in the United States of America, of engineers working in the motion imaging industries. An internationally-recognized standards developing organization, SMPTE has standards.)

Demise of analog HD systems

However, even that limited standardization of HDTV did not lead to its adoption, principally for technical and economic reasons. Early HDTV commercial experiments such as NHK's MUSE required over four times the bandwidth of a standard-definition broadcast, and despite efforts made to shrink the required bandwidth down to about two times that of SDTV, it was still only distributable by satellite with one channel shared on a daily basis between seven broadcasters. In addition, recording and reproducing an HDTV signal was a significant technical challenge in the early years of HDTV. Japan remained the only country with successful public broadcast analog HDTV. Digital HDTV broadcasting started in 2000 in Japan, and the analog service ended in the early hours of 1 October 2007.

In Europe, analogue 1,250-line HD-MAC test broadcasts were performed in the early 1990s, but did not lead to any established public broadcast service.

Inaugural HDTV broadcast in the United States

HDTV technology was introduced in the United States in the 1990s by the Digital HDTV Grand Alliance The Grand Alliance was a consortium created in 1993 at the behest of the Federal Communications Commission (FCC) to develop the American digital television (SDTV, EDTV) and HDTV specification, with the aim of pooling the best work from different companies. It consisted of AT&T, General Instrument Corporation, Massachusetts Institute of, a group of television companies and MIT The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological research. MIT is one of two private land-grant universities[b] and is also a sea-grant and space-.[10][11] Field testing of HDTV at 199 sites in the United States was completed August 14, 1994.[12] The first public HDTV broadcast in the United States occurred on July 23, 1996 when the Raleigh, North Carolina Raleigh is the capital city of the state of North Carolina, the seat of Wake County and the second largest city in North Carolina (after Charlotte). Raleigh is known as the "City of Oaks" for its many oak trees. According to the U.S. Census Bureau, the city's estimated population on July 1, 2008 was 401,552 (a 42% increase from the 2000 television station WRAL-HD began broadcasting from the existing tower of WRAL-TV south-east of Raleigh, winning a race to be first with the HD Model Station in Washington, D.C. Washington, D.C. , formally the District of Columbia and commonly referred to as Washington, the District, or simply D.C., is the capital of the United States, founded on July 16, 1790. The City of Washington was originally a separate municipality within the Territory of Columbia until an act of Congress in 1871 effectively merged the City and the, which began broadcasting July 31, 1996.[13][14][15] The American Advanced Television Systems Committee The Advanced Television Systems Committee is the group, established in 1982, that developed the eponymous ATSC Standards for digital television in the United States, also adopted by Canada, Mexico, South Korea, and recently Honduras and is being considered by other countries (ATSC) HDTV system had its public launch on October 29, 1998, during the live coverage of astronaut John Glenn's return mission to space on board the Space Shuttle Discovery.[16] The signal was transmitted coast-to-coast, and was seen by the public in science centers, and other public theaters specially equipped to receive and display the broadcast.[16][17]

European HDTV broadcasts

Although HDTV broadcasts had been demonstrated in Europe since the early 1990s, the first regular broadcasts started on January 1, 2004 when Euro1080 launched the HD1 channel with the traditional Vienna New Year's Concert. Test transmissions had been active since the IBC exhibition in September 2003, but the New Year's Day broadcast marked the official start of the HD1 channel, and the start of HDTV in Europe.[18]

Euro1080, a division of the Belgian TV services company Alfacam, broadcast HDTV channels to break the pan-European stalemate of "no HD broadcasts mean no HD TVs bought means no HD broadcasts..." and kick-start HDTV interest in Europe.[19] The HD1 channel was initially free-to-air and mainly comprised sporting, dramatic, musical and other cultural events broadcast with a multi-lingual soundtrack on a rolling schedule of 4 or 5 hours per day.

These first European HDTV broadcasts used the 1080i format with MPEG-2 compression on a DVB-S signal from SES Astra's 1H satellite at Europe's main DTH Astra 19.2°E position. Euro1080 transmissions later changed to MPEG-4/AVC compression on a DVB-S2 signal in line with subsequent broadcast channels in Europe.

In the following six years, the number of HD channels broadcasting to Europe has grown considerably, particularly from the pay-TV broadcasters. At the end of 2009, there were 114 HD channels broadcasting from Astra satellites.[20]

European HD Channels via Astra by Country (end 2009)
UK 39 Poland 36 France 19 Germany 17
Sweden 16 Norway 16 Finland 16 Denmark 15
Italy 14 Portugal 11 Spain 9 Hungary 9
Netherlands 8 Belgium 8 Czech Republic 8 Slovakia 7
Albania 7 Bulgaria 5 Austria 2 Pan-European 5

The number of households able to view HD channels has also increased. According to SES Astra, at the year-end 2009 there were 6 million households receiving HD channels via Astra satellites, and it is expected that by 2013 there will be 24.7 million households in Europe watching HD channels via satellite.

European HD-via-Astra Homes by Country/Region (end 2009)
UK 2,880,000 Germany 1,300,000
France 820,000 Austria 180,000
Benelux 27,000 Czech Republic 60,000
Scandinavia 108,000 Poland 300,000
Spain 98,000

Notation

HDTV broadcast systems are identified with three major parameters:

If all three parameters are used, they are specified in the following form: [frame size][scanning system][frame or field rate] or [frame size]/[frame or field rate][scanning system].[citation needed] Often, frame size or frame rate can be dropped if its value is implied from context. In this case the remaining numeric parameter is specified first, followed by the scanning system.

For example, 1920×1080p25 identifies progressive scanning format with 25 frames per second, each frame being 1,920 pixels wide and 1,080 pixels high. The 1080i25 or 1080i50 notation identifies interlaced scanning format with 25 frames (50 fields) per second, each frame being 1,920 pixels wide and 1,080 pixels high.[citation needed] The 1080i30 or 1080i60 notation identifies interlaced scanning format with 30 frames (60 fields) per second, each frame being 1,920 pixels wide and 1,080 pixels high.[citation needed] The 720p60 notation identifies progressive scanning format with 60 frames per second, each frame being 720 pixels high; 1,280 pixels horizontally are implied.

50Hz systems allow for only three scanning rates: 25i, 25p and 50p. 60Hz systems operate with much wider set of frame rates: 23.976p, 24p, 29.97i/59.94i, 29.97p, 30p, 59.94p and 60p. In the days of standard definition television, the fractional rates were often rounded up to whole numbers, e.g. 23.976p was often called 24p, or 59.94i was often called 60i. High definition television allows using both fractional and whole rates, therefore strict usage of notation is required. Nevertheless, 29.97i/59.94i is almost universally called 60i, likewise 23.976p is called 24p.[citation needed]

For commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames per second.[citation needed]

One aspect of the HDTV that hasn't received a naming standard is color. Until recently, the color of each pixel was regulated by three 8-bit color values, each representing the level of red, blue, and green which defined a pixel color. Together the 24 total bits defining color yielded just under 17 million possible pixel colors. Recently, some manufacturers have designed systems that can employ 10 bits for each color (30 bits total) which provides for a palette of 1 billion colors. They contend that this provides a much richer picture. Until the naming of this criterion is standardized, consumers will have to do research to ensure that a piece of equipment supports this feature.

Most HDTV systems support resolutions and frame rates defined either in the ATSC table 3, or in EBU specification. The most common are noted below.

High-definition display resolutions

Video format supported Native resolution (W×H) Pixels Aspect ratio (W:H) Description
Actual Advertised (Mpixel) Image Pixel
720p 1280x720 1024×768 XGA 786,432 0.8 16:9 4:3 Typically a PC resolution (XGA); also a native resolution on many entry-level plasma displays with non-square pixels.
1280×720 921,600 0.9 16:9 1:1 Standard HDTV resolution and a typical PC resolution (WXGA), frequently used by video projectors; also used for 750-line video, as defined in SMPTE 296M, ATSC A/53, ITU-R BT.1543.
1366×768 WXGA 1,049,088 1.0 683:384 (approx. 16:9) 1:1 approx. A typical PC resolution (WXGA); also used by many HD ready TV displays based on LCD technology.
1080p/1080i 1920×1080 1920×1080 2,073,600 2.1 16:9 1:1 Standard HDTV resolution, used by Full HD and HD ready 1080p TV displays such as high-end LCD, Plasma and rear projection TVs, and a typical PC resolution (lower than WUXGA); also used for 1125-line video, as defined in SMPTE 274M, ATSC A/53, ITU-R BT.709;
Video format supported Screen resolution (W×H) Pixels Aspect ratio (W:H) Description
Actual Advertised (Mpixel) Image Pixel
720p 1780×956 1780×956 Clean Aperture 876,096 0.9 16:9 1:1 Used for 750-line video with raster artifact/overscan compensation, as defined in SMPTE 296M.
1080p 1920×1080 1888×1062 Clean aperture 2,001,280 2.0 16:9 1:1 Used for 1125-line video with faster artifact/overscan compensation, as defined in SMPTE 274M.
1080i 1920×1080 1440×1080 HDCAM/HDV 1,555,200 1.6 16:9 4:3 Used for anamorphic 1125-line video in the HDCAM and HDV formats introduced by Sony and defined (also as a luminance subsampling matrix) in SMPTE D11.

Standard frame or field rates

A comparison of multiple TV resolution standards as if it were viewed on a fixed-pixel display at full 1080p resolution. View at full size for proper comparison.

At a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or anamorphic stretching, thus increasing the effective image resolution.

The optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. The field and frame rate should match the source and the resolution. A very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed source.

There is a wide spread confusion of using terms like PAL or SECAM or NTSC relating to HD material. PAL, SECM, NTSC are only standard definition standards, not HD. There is no specific technical reason to keep 25Hz as HD frame rate in a former PAL country.

Types of media

Standard 35 mm photographic film used for cinema projection has higher resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second. To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate of 25 frames per second, causing an acceleration of 4.1 percent, which is generally considered acceptable. In NTSC-system countries, the TV scan rate of 30 frames per second would cause a perceptible acceleration if the same were attempted, and the necessary correction is performed by a technique called 3:2 pull-down: over each successive pair of film frames, one is held for three video fields (1/20 of a second) and the next is held for two video fields (1/30 of a second), giving a total time for the two frames of 1/12 of a second and thus achieving the correct average film frame rate.

See also: Telecine

Non-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode. 720p also imposes less strenuous storage and decoding requirements compared to both 1080i and 1080p. 1080p is usually used for Blu-ray Disc.

Contemporary systems

Main article: Large-screen television technology Components of a typical satellite HDTV system: 1. HDTV Monitor 2. HD satellite receiver 3. Standard satellite dish 4. HDMI cable, DVI-D and audio cables, or audio and component video cables

Besides an HD-ready television set, other equipment may be needed to view HD television. In the US, Cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD.[21]

High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV, the high definition Blu-ray video disc (BD), internet downloads, the Blu-ray disc compatible Sony PlayStation 3 video game console (PS3), and the Microsoft Xbox 360 video game console.

Recording and compression

Main article: High-definition pre-recorded media and compression

HDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD recorders), or an HDTV-ready HTPC. Some cable boxes are capable of receiving or recording two or more broadcasts at a time in HDTV format, and HDTV programming, some free, some for a fee, can be played back with the cable company's on-demand feature.

The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available in the consumer market until recently. In 2008 the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in an uncompressed MPEG transport stream (.ts) file or Blu-ray format .m2ts file on the hard drive or DVD burner of a computer connected to the PVR through a USB 2.0 interface.

Realtime MPEG-2 compression of an uncompressed digital HDTV signal is prohibitively expensive for the consumer market at this time, but should become inexpensive within several years (although this is more relevant for consumer HD camcorders than recording HDTV). Analog tape recorders with bandwidth capable of recording analog HD signals such as W-VHS recorders are no longer produced for the consumer market and are both expensive and scarce in the secondary market.

In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" Firewire (IEEE 1394) upon request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes, but some cable TV companies have. As of July 2004[update], boxes are not included in the FCC mandate. This content is protected by encryption known as 5C.[22] This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all fair use of the content.

TV resolution

Digital video resolutions
Designation
Usage Examples Definition (lines) Rate (Hz)
Interlaced (fields) Progressive (frames)
Low; MP@LL
LDTV, VCD 240; 288 (SIF) 24, 30; 25
Standard; MP@ML
SDTV, SVCD, DVD, DV 480 (NTSC, PAL-M) 60 24, 30
576 (PAL, SECAM) 50 25
Enhanced
EDTV 480; 576 60; 50
High; MP@HL
HDTV, Blu-ray Disc, HD DVD, HDV 720 24, 30, 60; 25, 50
1080 50, 60 24, 30; 25
This table illustrates total horizontal and vertical pixel resolution via box size. It does not accurately reflect the screen or pixel shape (aspect ratio) of these formats, which is either 4:3, or 16:9.

See also

Wikimedia Commons has media related to: High-definition television

References

  1. ^ "SBS jubilant with its 576p HD broadcasts". http://www.broadcastandmedia.com/articles/ff/0c0276ff.asp.
  2. ^ "HDTV in the Russian Federation: problems and prospects of implementation (in Russian)". http://rus.625-net.ru/625/2007/01/tvch.htm.
  3. ^ "Researchers Craft HDTV's Successor". http://www.pcworld.com/article/id,132289-c,hdtv/article.html.
  4. ^ "Digital TV Tech Notes, Issue #2". http://www.tech-notes.tv/Archive/tech_notes_002.htm.
  5. ^ James Sudalnik and Victoria Kuhl, "High definition television"
  6. ^ "High definition television comes of age thanks to ITU". http://www.itu.int/ITU-R/index.asp?category=information&link=hdtv-25&lang=en.
  7. ^ "History of the DVB Project". http://www.dvb.org/about_dvb/history/.
  8. ^ Bob Morris (2003-07-13). "The true origins of the 16:9 HDTV aspect ratio!". rec.arts.movies.tech. (Web link). Retrieved on 2010-01-16.
  9. ^ "Digital TV Tech Notes, Issue #41". http://www.tech-notes.tv/Archive/tech_notes_041.htm.
  10. ^ The Grand Alliance includes AT&T, General Instrument, MIT, Philips, Sarnoff, Thomson, and Zenith)
  11. ^ Carlo Basile et al. (1995). "The U.S. HDTV standard: the Grand Alliance". IEEE Spectrum 32 (4): 36–45.
  12. ^ HDTV field testing wraps up
  13. ^ History of WRAL Digital
  14. ^ WRAL-HD begins broadcasting HDTV
  15. ^ Comark transmitter first in at Model Station
  16. ^ a b Albiniak, Paige (1998-11-02). "HDTV: Launched and Counting.". Broadcasting and cable (BNET). http://findarticles.com/p/articles/mi_hb5053/is_199811/ai_n18386452?tag=content;col1. Retrieved 2008-10-24.
  17. ^ "Space Shuttle Discovery: John Glenn Launch". Internet Movie Database. 1998. http://www.imdb.com/title/tt0384554/. Retrieved 2008-10-25.
  18. ^ SES ASTRA (October 23, 2003). "SES ASTRA and Euro1080 to pioneer HDTV in Europe". Press release. http://www.ses-astra.com/business/en/news-events/press-archive/2003/23-10-03/index.php.
  19. ^ Bains, Geoff. "Take The High Road" What Video & Widescreen TV (April, 2004) 22-24
  20. ^ Astra Satellite Monitor survey SES-Astra Presentation March 17, 2010
  21. ^ "HDTV information". http://www.hidefster.com/HDTV_blog/?cat=9.
  22. ^ "5C Digital Transmission Content Protection White Paper" (pdf). 1998-07-14. http://www.dtcp.com/data/wp_spec.pdf. Retrieved 2006-06-20.

Categories: ATSC | High-definition television | Film and video technology | Digital television | Consumer electronics

 

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Would getting high definition on my television effect my Xbox 360?
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A. It will make the picture and sound better. Wont hurt it. You mean you're getting a new HD TV right? You can get HD channels on a regular TV but without an HDTV they wont look any different. good luck!
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