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High-definition television (HDTV) describes a
television Television (TV) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission. Television is a mass medium for advertising, ...
or video system which provides a substantially higher
image resolution Image resolution is the level of detail of an image. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies ...
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 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 ...
(SDTV). It is the standard video format used in most broadcasts: terrestrial broadcast television,
cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with bro ...
,
satellite television Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems ...
.


Formats

HDTV may be transmitted in various formats: *
720p 720p (720 lines progressive) is a progressive HD signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9, normally known as widescreen HD (1.78:1). All major HD broadcasting standards (such as SMPTE 292M) includ ...
(): 921,600 pixels *
1080i In high-definition television (HDTV) and video display technology, 1080i is a video display format with 1080 lines of vertical resolution and Interlaced video, interlaced scanning method. This format was once a standard in HDTV. It was particular ...
()
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. Th ...
scan: 1,036,800 pixels (≈1.04Mpx). *
1080p 1080p (1920 × 1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the sc ...
() 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 clearer, more detailed picture. In addition, progressive scan and higher frame rates result in a picture with less flicker and better rendering of fast motion. Modern HDTV began broadcasting in 1989 in Japan, under the
MUSE In ancient Greek religion and Greek mythology, mythology, the Muses (, ) were the Artistic inspiration, inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the poetry, lyric p ...
/Hi-Vision analog system. HDTV was widely adopted worldwide in the late 2000s.


Standards

All modern high-definition broadcasts utilize
digital television Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an ...
standards. The major digital television broadcast standards used for terrestrial, cable, satellite, and mobile devices are: * DVB, originating in Europe and also used in much of Asia, Africa, and Australia * ATSC, used in much of North America *
DTMB DTMB (Digital Terrestrial Multimedia Broadcast) is the digital TV standard for mobile and fixed devices, developed in the People's Republic of China. It is used there and in both of their special administrative regions (Hong Kong and Macau), and ...
, used in China and some neighboring countries *
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 ...
, used in two incompatible variations in Japan and South America *
DMB DMB may refer to: * " D.M.B.", a song by ASAP Rocky * DMB Development, a Limited Liability Corporation based in Scottsdale, Arizona * DaMarcus Beasley, nicknamed DMB, an American soccer player * Dave Matthews Band, a U.S. rock band * Del McCoury B ...
, used by mobile devices in South Korea These standards use a variety of
video codec A video codec is software or Computer hardware, hardware that data compression, compresses and Uncompressed video, decompresses digital video. In the context of video compression, ''codec'' is a portmanteau of ''encoder'' and ''decoder'', while ...
s, some of which are also used for
internet video Internet video (also known as online video) is digital video that is distributed over the internet. Internet video exists in several formats, the most notable being MPEG-4i AVC, AVCHD, FLV, and MP4. There are several online video hosting s ...
.


History

The term ''high definition'' once described a series of television systems first announced in 1933 and launched starting in August 1936; 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 ongoing competition between companies and nations to create true HDTV spanned the entire 20th century, as each new system became higher definition than the last. In the early 21st century, this race has continued with 4K, 5K and 8K systems. The British high-definition TV service started trials in August 1936 and a regular service on 2 November 1936 using both the (mechanical) Baird 240 line sequential scan (later referred to as ''progressive'') and the (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. The number of television lines influences the image resolution, or quality of the picture. It ...
interlaced systems. The Baird system was discontinued in February 1937. In 1938 France followed with its own 441-line system, variants of which were also used by a number of other countries. The US
NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...
525-line system joined in 1941. In 1949 France introduced an even higher-resolution standard at
819 line 819-line was an analog monochrome TV system developed and used in France as television broadcast resumed after World War II. Transmissions started in 1949 and were active up to 1985, although limited to France, Belgium and Luxembourg. It is a ...
s, a system that would have been high definition even by modern standards, if it had not required such bandwidth for a color version, which prevented the addition of other TV channels (nevertheless, it remained in use until 1983). All of these systems used interlacing and a 4:3
aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...
except the 240-line system which was progressive (actually described at the time by the technically correct term ''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 as the video baseband bandwidth was required to be not more than 3 MHz. Color broadcasts started at similar line counts, first with the US NTSC color system in 1953, which was compatible with the earlier monochrome systems and therefore had the same 525 lines per frame. European standards did not follow until the 1960s, when the
PAL Phase Alternating Line (PAL) is a color encoding system for analog 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 (25 ...
and
SECAM SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''sequential colour memory''), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. ...
color systems were added to the monochrome 625-line broadcasts. The
NHK , also known by its Romanization of Japanese, romanized initialism NHK, is a Japanese public broadcasting, public broadcaster. It is a statutory corporation funded by viewers' payments of a television licence, television license fee. NHK ope ...
(Japan Broadcasting Corporation) began researching to "unlock the fundamental mechanism of video and sound interactions with the five human senses" in 1964, after the Tokyo Olympics. NHK set out to create an HDTV system that scored much higher in subjective tests than NTSC's previously dubbed ''HDTV''. This new system, NHK Color, created in 1972, included 1125 lines, a 5:3 (1.67:1) aspect ratio and 60 Hz refresh rate. The Society of Motion Picture and Television Engineers (SMPTE), headed by Charles Ginsburg, became the testing and study authority for HDTV technology in the international theater. SMPTE would test HDTV systems from different companies from every conceivable perspective, but the problem of combining the different formats plagued the technology for many years. There were four major HDTV systems tested by SMPTE in the late 1970s, and in 1979 an SMPTE study group released ''A Study of High Definition Television Systems'': * EIA monochrome: 4:3 aspect ratio, 1023 lines, 60 Hz * NHK color: 5:3 aspect ratio, 1125 lines, 60 Hz * NHK monochrome: 4:3 aspect ratio, 2125 lines, 50 Hz * BBC colour: 8:3 aspect ratio, 1501 lines, 60 Hz Since the formal adoption of Digital Video Broadcasting's (DVB) widescreen HDTV transmission modes in the mid to late 2000s; the 525-line
NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...
(and
PAL-M PAL-M was the analog color TV system used in Brazil since early 1972, making it the first South American country to broadcast in color. It is unique among analog TV systems in that it combines the 525-line 30 frames-per-second System M ...
) systems, as well as the European 625-line
PAL Phase Alternating Line (PAL) is a color encoding system for analog 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 (25 ...
and
SECAM SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''sequential colour memory''), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. ...
systems, have been regarded as ''standard definition'' television systems.


Analog systems

Early HDTV broadcasting used
analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analog ...
technology that was later converted to
digital television Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an ...
with
video compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression ...
. In 1949, France started its transmissions with an 819 lines system (with 737 active lines). The system was monochrome only and was used only on VHF for the first French TV channel. It was discontinued in 1983. In 1958, the
Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...
developed ''Тransformator'' (, meaning ''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 by either the military or consumer broadcasting. In 1986, the
European Community The European Economic Community (EEC) was a regional organisation created by the Treaty of Rome of 1957,Today the largely rewritten treaty continues in force as the ''Treaty on the functioning of the European Union'', as renamed by the Lisbo ...
proposed
HD-MAC HD-MAC (High Definition Multiplexed Analogue Components) was a broadcast television systems, broadcast television standard proposed by the European Commission in 1986, as part of Eureka (organisation), Eureka 95 project. It belongs to the Multiplex ...
, an analog HDTV system with 1,152 lines. A public demonstration took place for the
1992 Summer Olympics The 1992 Summer Olympics (, ), officially the Games of the XXV Olympiad (, ) and officially branded as Barcelona '92, were an international multi-sport event held from 25 July to 9 August 1992 in Barcelona, Catalonia, Spain. Beginning in 1994 ...
in Barcelona. However HD-MAC was scrapped in 1993 and the DVB project was formed, which would foresee development of a digital HDTV standard.


Japan

In 1979, the Japanese public broadcaster
NHK , also known by its Romanization of Japanese, romanized initialism NHK, is a Japanese public broadcasting, public broadcaster. It is a statutory corporation funded by viewers' payments of a television licence, television license fee. NHK ope ...
first developed consumer high-definition television with a 5:3 display aspect ratio. The system, known as Hi-Vision or MUSE after its
multiple sub-Nyquist sampling encoding MUSE (Multiple sub-Nyquist Sampling Encoding), commercially known as Hi-Vision (a contraction of HIgh-definition teleVISION) was a Japanese analog high-definition television system, with design efforts going back to 1979. Traditional interlaced v ...
(MUSE) for encoding the signal, required about twice the bandwidth of the existing NTSC system but provided about four times the resolution (1035i/1125 lines). In 1981, the MUSE system was demonstrated for the first time in the United States, using the same 5:3 aspect ratio as the Japanese system. Upon visiting a demonstration of MUSE in Washington, US President
Ronald Reagan Ronald Wilson Reagan (February 6, 1911 – June 5, 2004) was an American politician and actor who served as the 40th president of the United States from 1981 to 1989. He was a member of the Republican Party (United States), Republican Party a ...
was impressed and officially declared it "a matter of national interest" to introduce HDTV to the US. NHK taped the
1984 Summer Olympics The 1984 Summer Olympics (officially the Games of the XXIII Olympiad and commonly known as Los Angeles 1984) were an international multi-sport event held from July 28 to August 12, 1984, in Los Angeles, California, United States. It marked the ...
with a Hi-Vision camera, weighing 40 kg. Satellite test broadcasts started June 4, 1989, the first daily high-definition programs in the world, with regular testing starting on November 25, 1991, or "Hi-Vision Day"dated exactly to refer to its 1,125-lines resolution. Regular broadcasting of BS-9ch commenced on November 25, 1994, which featured commercial and NHK programming. Several systems were proposed as the new standard for the US, including the Japanese MUSE system, but all were rejected by the
Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains j ...
(FCC) because of their higher bandwidth requirements. At this time, the number of television channels was growing rapidly and bandwidth was already a problem. A new standard had to be more efficient, needing less bandwidth for HDTV than the existing NTSC.


Decrease of analog HD systems

The limited standardization of analog HDTV in the 1990s did not lead to global HDTV adoption as technical and economic constraints at the time did not permit HDTV to use bandwidths greater than normal television. Early HDTV commercial experiments, such as NHK's MUSE, required over four times the bandwidth of a standard-definition broadcast. Despite efforts made to reduce analog HDTV to about twice the bandwidth of SDTV, these television formats were still distributable only by satellite. In Europe too, the HD-MAC standard was considered not technically viable. In addition, recording and reproducing an HDTV signal was a significant technical challenge in the early years of HDTV (
Sony HDVS Sony HDVS (High-Definition Video System) is a range of high-definition video equipment developed in the 1980s to support the Japanese Hi-Vision standard which was an early analog high-definition television system (used in multiple sub-Nyquist s ...
). Japan remained the only country with successful
public broadcasting Public broadcasting (or public service broadcasting) is radio, television, and other electronic media outlets whose primary mission is public service with a commitment to avoiding political and commercial influence. Public broadcasters receive f ...
of analog HDTV, with seven broadcasters sharing a single channel. However, the Hi-Vision/MUSE system also faced commercial issues when it launched on November 25, 1991. Only 2,000 HDTV sets were sold by that day, rather than the enthusiastic 1.32 million estimation. Hi-Vision sets were very expensive, up to US$30,000 each, which contributed to its low consumer adaption. A Hi-Vision VCR from
NEC is a Japanese multinational information technology and electronics corporation, headquartered at the NEC Supertower in Minato, Tokyo, Japan. It provides IT and network solutions, including cloud computing, artificial intelligence (AI), Inte ...
released at Christmas time retailed for US$115,000. In addition, the United States saw Hi-Vision/MUSE as an outdated system and had already made it clear that it would develop an all-digital system. Experts thought the commercial Hi-Vision system in 1992 was already eclipsed by digital technology developed in the U.S. since 1990. This was an American victory against the Japanese in terms of technological dominance. By mid-1993 prices of receivers were still as high as 1.5 million
yen The is the official currency of Japan. It is the third-most traded currency in the foreign exchange market, after the United States dollar and the euro. It is also widely used as a third reserve currency after the US dollar and the euro. T ...
(US$15,000). On February 23, 1994, a top broadcasting administrator in Japan admitted failure of its analog-based HDTV system, saying the U.S. digital format would be more likely a worldwide standard. However this announcement drew angry protests from broadcasters and electronic companies who invested heavily into the analog system. As a result, he took back his statement the next day saying that the government will continue to promote Hi-Vision/MUSE. That year NHK started development of
digital television Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an ...
in an attempt to catch back up to America and Europe. This resulted in the
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 ...
format. Japan started digital satellite and HDTV broadcasting in December 2000.


Rise of digital compression

High-definition digital television was not possible with
uncompressed video Uncompressed video is digital video that either has never been compressed or was generated by decompressing previously compressed digital video. It is commonly used by video cameras, video monitors, video recording devices (including general-pur ...
, which requires a
bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...
exceeding 1
Gbit/s In telecommunications, data transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...
for studio-quality HD
digital video Digital video is an electronic representation of moving visual images (video) in the form of encoded digital data. This is in contrast to analog video, which represents moving visual images in the form of analog signals. Digital video comprises ...
. Digital HDTV was made possible by the development of
discrete cosine transform A discrete cosine transform (DCT) expresses a finite sequence of data points in terms of a sum of cosine functions oscillating at different frequency, frequencies. The DCT, first proposed by Nasir Ahmed (engineer), Nasir Ahmed in 1972, is a widely ...
(DCT)
video compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression ...
. DCT coding is a
lossy In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...
image compression technique that was first proposed by Nasir Ahmed in 1972, and was later adapted into a motion-compensated DCT algorithm for
video coding standards A video coding format (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on ...
such as the
H.26x The Video Coding Experts Group or Visual Coding Experts Group (VCEG, also known as Question 6) is a working group of the ITU Telecommunication Standardization Sector (ITU-T) concerned with standards for compression coding of video, images, audio ...
formats from 1988 onwards and the
MPEG The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by International Organization for Standardization, ISO and International Electrotechnical Commission, IEC that sets standards for media coding, includ ...
formats from 1993 onwards. Motion-compensated DCT compression significantly reduces the amount of bandwidth required for a digital TV signal. By 1991, it had achieved
data compression ratio Data compression ratio, also known as compression power, is a measurement of the relative reduction in size of data representation produced by a data compression algorithm. It is typically expressed as the division of uncompressed size by compress ...
s from 8:1 to 14:1 for near-studio-quality HDTV transmission, down to 70140 
Mbit/s In telecommunications, data transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...
. Between 1988 and 1991, DCT video compression was widely adopted as the
video coding standard A video coding format (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on ...
for HDTV implementations, enabling the development of practical digital HDTV. Dynamic
random-access memory Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows ...
(
DRAM Dram, DRAM, or drams may refer to: Technology and engineering * Dram (unit), a unit of mass and volume, and an informal name for a small amount of liquor, especially whisky or whiskey * Dynamic random-access memory, a type of electronic semicondu ...
) was also adopted as
framebuffer A framebuffer (frame buffer, or sometimes framestore) is a portion of random-access memory (RAM) containing a bitmap that drives a video display. It is a memory buffer containing data representing all the pixels in a complete video frame. Mode ...
semiconductor memory, with the DRAM
semiconductor industry The semiconductor industry is the aggregate of companies engaged in the design and fabrication of semiconductors and semiconductor devices, such as transistors and integrated circuits. Its roots can be traced to the invention of the transistor ...
's increased manufacturing and reducing prices important to the commercialization of HDTV. Since 1972,
International Telecommunication Union The International Telecommunication Union (ITU)In the other common languages of the ITU: * * is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information ...
's radio telecommunications sector (
ITU-R The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications. Its role is to manage the international radio-frequenc ...
) had been working on creating a global recommendation for Analog 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 Technical standard, standard for lossy compression of video and Audio frequency, audio. It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively ...
in 1993 led to the acceptance of recommendations
ITU-R BT.709 ITU-R Recommendation 709, usually abbreviated Rec. 709, BT.709, or ITU-R 709, is a standard developed by the Radiocommunication Sector of the International Telecommunication Union (ITU-R) for image encoding and signal characteristics ...
. In anticipation of these standards, the DVB organization was formed. It was alliance of broadcasters, consumer electronics manufacturers and regulatory bodies. The DVB develops and agrees upon specifications which are formally standardised by
ETSI The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization operating in the field of Information and communications technology, information and communications. ETSI supports the de ...
. DVB created first the standard for
DVB-S Digital Video Broadcasting – Satellite (DVB-S) is the original DVB standard for satellite television and dates from 1995, in its first release, while development lasted from 1993 to 1997. The first commercial applications were by Canal+ in ...
digital satellite TV,
DVB-C Digital Video Broadcasting - Cable (DVB-C) is the Digital Video Broadcasting, DVB European consortium standard for the broadcast transmission of digital television over coaxial cable, cable. This system transmits an MPEG-2 or MPEG-4 family digita ...
digital cable TV and
DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in Singapore in Fe ...
digital terrestrial TV. These broadcasting systems can be used for both SDTV and HDTV. In the US the Grand Alliance proposed ATSC as the new standard for SDTV and HDTV. Both ATSC and DVB were based on the
MPEG-2 MPEG-2 (a.k.a. H.222/H.262 as was defined by the ITU) 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 ...
standard, although DVB systems may also be used to transmit video using the newer and more efficient H.264/MPEG-4 AVC 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's radio telecommunications sector (ITU-R) 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, the world already having split into two camps, 25/50 Hz and 30/60 Hz, largely due to the differences in mains frequency. The IWP11/6 working party considered many views and throughout 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. An aspect ratio of 16:9 was duly agreed upon at the first meeting of the IWP11/6 working party at the BBC's Research and Development establishment in Kingswood Warren. The resulting ITU-R Recommendation ITU-R BT.709-2 ("
Rec. 709 ITU-R Recommendation 709, usually abbreviated Rec. 709, BT.709, or ITU-R 709, is a standard developed by the Radiocommunication Sector of the International Telecommunication Union (ITU-R) for image encoding and signal characteristics ...
") 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 p ...
, and the scan modes
1080i In high-definition television (HDTV) and video display technology, 1080i is a video display format with 1080 lines of vertical resolution and Interlaced video, interlaced scanning method. This format was once a standard in HDTV. It was particular ...
(1,080 actively interlaced lines of resolution) and
1080p 1080p (1920 × 1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the sc ...
(1,080 progressively scanned lines). The British
Freeview HD Freeview is the United Kingdom's sole digital terrestrial television platform. It is operated by Everyone TV and DTV Services Ltd, a joint venture between the BBC, ITV, Channel 4, 5 and Sky. It was launched on 30 October 2002, taking over th ...
trials used 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, and so was not included, although 1920×1080i and 1280×720p systems for a range of frame and field rates were defined by several US
SMPTE The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded by Charles Francis Jenkins in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and e ...
standards.)


Inaugural HDTV broadcast in the United States

HDTV technology was introduced in the United States in the early 1990s and made official in 1993 by the Digital HDTV Grand Alliance, a group of television, electronic equipment, communications companies consisting of AT&T Bell Labs,
General Instrument General Instrument (GI) was an American electronics manufacturer based in Horsham, Pennsylvania, specializing in semiconductors and cable television equipment. They formed in New York City in 1923 as an electronics manufacturer. During the 1950s ...
,
Philips Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarter ...
, Sarnoff,
Thomson Thomson may refer to: Names * Thomson (surname), a list of people with this name and a description of its origin * Thomson baronets, four baronetcies created for persons with the surname Thomson Businesses and organizations * SGS-Thomson M ...
,
Zenith The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The z ...
and the
Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...
. Field testing of HDTV at 199 sites in the United States was completed August 14, 1994. The first public HDTV broadcast in the United States occurred on July 23, 1996, when the
Raleigh, North Carolina Raleigh ( ) is the List of capitals in the United States, capital city of the U.S. state of North Carolina. It is the List of municipalities in North Carolina, second-most populous city in the state (after Charlotte, North Carolina, Charlotte) ...
television station WRAL-HD began broadcasting from the existing tower of
WRAL-TV WRAL-TV (channel 5) is a television station licensed to Raleigh, North Carolina, United States, serving as the NBC affiliate for the Research Triangle area. It is the flagship station of the locally based Capitol Broadcasting Company, which has ...
southeast 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 known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...
, which began broadcasting July 31, 1996 with the callsign WHD-TV, based out of the facilities of
NBC The National Broadcasting Company (NBC) is an American commercial broadcast television and radio network serving as the flagship property of the NBC Entertainment division of NBCUniversal, a subsidiary of Comcast. It is one of NBCUniversal's ...
owned and operated station
WRC-TV WRC-TV (channel 4) is a television station in Washington, D.C., serving as the market's NBC outlet. It is owned and operated by the network's NBC Owned Television Stations division alongside Class A television service, Class A Telemundo outlet W ...
. The American
Advanced Television Systems Committee The Advanced Television Systems Committee (ATSC) is an international nonprofit organization developing technical standards for digital terrestrial television and data broadcasting. ATSC's 120-plus member organizations represent the broadcast, ...
(ATSC) HDTV system had its public launch on October 29, 1998, during the live coverage of astronaut
John Glenn John Herschel Glenn Jr. (July 18, 1921 – December 8, 2016) was an American Marine Corps aviator, astronaut, businessman, and politician. He was the third American in space and the first to orbit the Earth, circling it three times in 1 ...
's return mission to space on board the
Space Shuttle The Space Shuttle is a retired, partially reusable launch system, reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. ...
''
Discovery Discovery may refer to: * Discovery (observation), observing or finding something unknown * Discovery (fiction), a character's learning something unknown * Discovery (law), a process in courts of law relating to evidence Discovery, The Discovery ...
''. 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.


European HDTV broadcasts

Between 1988 and 1991, several European organizations were working on discrete cosine transform (DCT) based digital
video coding standards A video coding format (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on ...
for both SDTV and HDTV. The EU 256 project by the CMTT and ETSI, along with research by Italian broadcaster
RAI (), commercially styled as since 2000 and known until 1954 as (RAI), is the national public broadcasting company of Italy, owned by the Ministry of Economy and Finance. RAI operates many terrestrial and subscription television channels a ...
, developed a DCT
video codec A video codec is software or Computer hardware, hardware that data compression, compresses and Uncompressed video, decompresses digital video. In the context of video compression, ''codec'' is a portmanteau of ''encoder'' and ''decoder'', while ...
that broadcast near-studio-quality HDTV transmission at about 70140 Mbit/s. The first HDTV transmissions in Europe, albeit not direct-to-home, began in 1990, when RAI broadcast the
1990 FIFA World Cup The 1990 FIFA World Cup was the 14th FIFA World Cup, a quadrennial Association football, football tournament for men's senior national teams. It was held from 8 June to 8 July 1990 in Italy, the second country to host the event for a second ...
using several experimental HDTV technologies, including the digital DCT-based EU 256 codec, the mixed analog-digital
HD-MAC HD-MAC (High Definition Multiplexed Analogue Components) was a broadcast television systems, broadcast television standard proposed by the European Commission in 1986, as part of Eureka (organisation), Eureka 95 project. It belongs to the Multiplex ...
technology, and the analog
MUSE In ancient Greek religion and Greek mythology, mythology, the Muses (, ) were the Artistic inspiration, inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the poetry, lyric p ...
technology. The matches were shown in 8 cinemas in Italy, where the tournament was played, and 2 in Spain. The connection with Spain was made via the Olympus satellite link from
Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...
to
Barcelona Barcelona ( ; ; ) is a city on the northeastern coast of Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second-most populous municipality of Spain. With a population of 1.6 million within c ...
and then with a
fiber optic An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...
connection from Barcelona to
Madrid Madrid ( ; ) is the capital and List of largest cities in Spain, most populous municipality of Spain. It has almost 3.5 million inhabitants and a Madrid metropolitan area, metropolitan area population of approximately 7 million. It i ...
. After some HDTV transmissions in Europe, the standard was abandoned in 1993, to be replaced by a digital format from DVB. The first regular broadcasts began on January 1, 2004, when the Belgian company
Euro1080 Euro1080 was the first commercial broadcaster in Europe to broadcast full-time high-definition television (HDTV) content. It was founded by Gabriel Fehervari in 2004 and is owned by Alfacam, of which declared bankrupt in 2013. The name orig ...
launched the HD1 channel with the traditional
Vienna New Year's Concert The Vienna New Year's Concert () is an annual concert of classical music performed by the Vienna Philharmonic on the morning of New Year's Day in Vienna, Austria. The concert occurs at the Musikverein at 11:15. The orchestra performs the same co ...
. Test transmissions had been active since the IBC exhibition in September 2003, but the New Year's Day broadcast marked the official launch of the HD1 channel, and the official start of direct-to-home HDTV in Europe. Euro1080, a division of the later defunct 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. The HD1 channel was initially
free-to-air Free-to-air (FTA) services are television (TV) and radio services broadcast in unencrypted form, allowing any person with the appropriate receiving equipment to receive the signal and view or listen to the content without requiring a subscri ...
and mainly comprised sporting, dramatic, musical and other cultural events broadcast with a multi-lingual soundtrack on a rolling schedule of four or five hours per day. These first European HDTV broadcasts used the 1080i format with MPEG-2 compression on a DVB-S signal from SES's
Astra 1H Astra 1H is one of the Astra communications satellites owned and operated by SES. History SES ordered its Hughes 601HP satellite, in 1995 for Astra 1H. Launch Astra-1H was launched on 18 June 1999 at 01:49:30 UTC, by a Proton-K / DM-2 ...
satellite. Euro1080 transmissions later changed to MPEG-4/AVC compression on a DVB-S2 signal in line with subsequent broadcast channels in Europe. Despite delays in some countries, the number of European HD channels and viewers has risen steadily since the first HDTV broadcasts, with SES's annual ''Satellite Monitor'' market survey for 2010 reporting more than 200 commercial channels broadcasting in HD from Astra satellites, 185 million HD capable TVs sold in Europe (£60 million in 2010 alone), and 20 million households (27% of all European digital satellite TV homes) watching HD satellite broadcasts (16 million via Astra satellites). In December 2009, the United Kingdom became the first European country to deploy high-definition content using the new
DVB-T2 DVB-T2 is an abbreviation for "Digital Video Broadcasting – Second Generation Terrestrial"; it is the extension of the television standard DVB-T, issued by the consortium DVB, devised for the broadcast transmission of digital terrestrial telev ...
transmission standard, as specified in the
Digital TV Group The DTG (Digital TV Group) is the association for British digital television broadcasters and annually publish and maintain the technical specifications for digital terrestrial television (DTT) in the United Kingdom, which is known as the D-Bo ...
(DTG)
D-book The D-Book is the UK technical specification for digital terrestrial television (DTT). The Digital TV Group (DTG) has published and maintained the D-Book for over a decade and the specification is updated annually to keep up with the pace of de ...
, on digital terrestrial television. The Freeview HD service contains 13 HD channels () and was rolled out region by region across the UK in accordance with the
digital switchover Digital usually refers to something using discrete digits, often binary digits. Businesses *Digital bank, a form of financial institution *Digital Equipment Corporation (DEC) or Digital, a computer company *Digital Research (DR or DRI), a software ...
process, finally being completed in October 2012. However, Freeview HD is not the first HDTV service over digital terrestrial television in Europe; Italy's
RAI (), commercially styled as since 2000 and known until 1954 as (RAI), is the national public broadcasting company of Italy, owned by the Ministry of Economy and Finance. RAI operates many terrestrial and subscription television channels a ...
started broadcasting in 1080i on April 24, 2008, using the DVB-T transmission standard. In October 2008, France deployed five high definition channels using DVB-T transmission standard on digital terrestrial distribution.


Notation

HDTV broadcast systems are identified with three major parameters: * Frame size in pixels is defined as ''number of horizontal pixels × number of vertical pixels'', for example ''1280 × 720'' or ''1920 × 1080''. Often the number of horizontal pixels is implied from context and is omitted, as in the case of ''720p'' and ''1080p''. * Scanning system is identified with the letter ''p'' for
progressive scan Progressive scanning (alternatively referred to as noninterlaced scanning) is a format of displaying, storing, or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to interlaced video us ...
ning or ''i'' for interlaced scanning. * Frame rate is identified as number of video frames per second. For interlaced systems, the number of frames per second should be specified, but it is not uncommon to see the field rate incorrectly used instead. If all three parameters are used, they are specified in the following form: '' rame sizescanning system] rame or field rate' or '' rame size rame or field ratescanning system]''. 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
pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ...
s 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. 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. The ''720p60'' notation identifies progressive scanning format with 60 frames per second, each frame being 720 pixels high; 1,280 pixels horizontally are implied. Systems using 50 Hz support three scanning rates: 50i, 25p and 50p, while 60 Hz systems support a much wider set of frame rates: 59.94i, 60i, 23.976p, 24p, 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. Sixty Hertz high definition television supports both fractional and slightly different integer rates, therefore strict usage of notation is required to avoid ambiguity. Nevertheless, 29.97p/59.94i is almost universally called 60i, likewise 23.976p is called 24p. For the 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. There is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a
RGB The RGB color model is an additive color model in which the red, green, and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three ...
color space using standardized algorithms. When transmitted directly through the Internet, the colors are typically pre-converted to 8-bit RGB channels for additional storage savings with the assumption that it will only be viewed only on a (
sRGB sRGB (standard RGB) is a colorspace, for use on monitors, printers, and the World Wide Web. It was initially proposed by HP and Microsoft in 1996 and became an official standard of the International Electrotechnical Commission (IEC) as IEC 6 ...
) computer screen. As an added benefit to the original broadcasters, the losses of the pre-conversion essentially make these files unsuitable for professional TV re-broadcasting. 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.


Display resolutions

At a minimum, HDTV has twice the linear resolution of
standard-definition television 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 ...
(SDTV), thus showing greater detail than either analog television or regular
DVD The DVD (common abbreviation for digital video disc or digital versatile disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any ki ...
. The technical standards for broadcasting HDTV also handle the 16:9
aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...
images without using letterboxing or
anamorphic Anamorphic format is a cinematography technique that captures widescreen images using recording media with narrower native Aspect ratio (image), aspect ratios. Originally developed for 35 mm movie film, 35 mm film to create widescreen pres ...
stretching, thus increasing the effective image resolution. A very high-resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The
lossy compression In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...
that is used in all digital HDTV storage and transmission systems will distort the received picture when compared to the uncompressed source.


Standard frame or field rates

ATSC and DVB define the following frame rates for use with the various broadcast standards: * 23.976 Hz (film-looking frame rate compatible with
NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...
clock speed standards) * 24 Hz (international film and ATSC high-definition material) * 25 Hz (PAL film, DVB standard-definition and high-definition material) * 29.97 Hz (NTSC film and standard-definition material) * 30 Hz (NTSC film, ATSC high-definition material) * 50 Hz (DVB high-definition material) * 59.94 Hz (ATSC high-definition material) * 60 Hz (ATSC high-definition material) The optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source, the transmitted field ratio, lines, and frame rate should match those of the source. PAL, SECAM and NTSC frame rates technically apply only to analog standard-definition television, not to digital or high definition broadcasts. However, with the rollout of digital broadcasting, and later HDTV broadcasting, countries retained their heritage systems. HDTV in former PAL and SECAM countries operates at a frame rate of 25/50 Hz, while HDTV in former NTSC countries operates at 30/60 Hz.


Types of media

High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable,
IPTV Internet Protocol television (IPTV), also called TV over broadband, is the service delivery of television over Internet Protocol (IP) networks. Usually sold and run by a Telephone company, telecom provider, it consists of broadcast live telev ...
,
Blu-ray Blu-ray (Blu-ray Disc or BD) is a digital optical disc data storage format designed to supersede the DVD format. It was invented and developed in 2005 and released worldwide on June 20, 2006, capable of storing several hours of high-defin ...
video disc (BD), and internet downloads. In the US, residents in the line of sight of television station broadcast antennas can receive free, over-the-air programming with a television set with an
ATSC tuner An ATSC (Advanced Television Systems Committee) tuner, often called an ATSC receiver or HDTV tuner, is a type of television tuner that allows reception of digital television (DTV) television channels that use ATSC standards, as transmitted by tel ...
via a TV aerial. Laws prohibit homeowners' associations and city government from banning the installation of antennas. Standard 35mm
photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the ...
used for cinema projection has a much higher
image resolution Image resolution is the level of detail of an image. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies ...
than HDTV systems, and is exposed and projected at a rate of 24
frames per second A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent. Frame and FRAME may also refer to: Physical objects In building construction *Framing (co ...
(frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate of 25 frame/s, causing a speedup of 4.1 percent, which is generally considered acceptable. In NTSC-system countries, the TV scan rate of 30 frame/s would cause a perceptible speedup if the same were attempted, and the necessary correction is performed by a technique called 3:2 pulldown: 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. 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/24, 1080i/30, 1080i/25, and 720p/30 is most often used on Blu-ray Disc.


Recording and compression

HDTV can be recorded to
D-VHS D-VHS (short for Digital VHS) is a digital video recording format developed by JVC in collaboration with Hitachi, Matsushita, and Philips. Introduced in December 1997, it was designed to record digital video, including high-definition content ...
(Digital-VHS or Data-VHS),
W-VHS W-VHS (Wide-VHS) is an HDTV-capable analog recording videocassette format created by JVC. The format was originally introduced on January 8, 1993 for use with Japan's Hi-Vision (aka MUSE), an early analog high-definition television system. ...
(analog only), to an HDTV-capable
digital video recorder A digital video recorder (DVR), also referred to as a personal video recorder (PVR) particularly in Canadian and British English, is an electronic device that records video in a digital format to a disk drive, USB flash drive, SD memory card, SS ...
(for example
DirecTV DirecTV, LLC is an American Multichannel television in the United States, multichannel video programming distributor based in El Segundo, California. Originally launched on June 17, 1994, its primary service is a digital Satellite television, s ...
's high-definition digital video recorder,
Sky HD Sky HD may refer to: *Sky+ HD, a high-definition television service provided by British Sky Broadcasting Group in the United Kingdom and Ireland *Sky HD (Italy) Sky Italia S.r.l. is an Italian satellite television platform owned by the American ...
's
set-top box A set-top box (STB), also known as a cable converter box, cable box, receiver, or simply box, and historically television decoder or a converter, is an information appliance device that generally contains a Tuner (radio)#Television, TV tuner inpu ...
,
Dish Network DISH Network L.L.C., often referred to as DISH, an abbreviation for Digital Sky Highway, is an American provider of satellite television and IPTV services and wholly owned subsidiary of EchoStar Corporation. The company was originally establ ...
's VIP 622 or VIP 722 high-definition digital video recorder receivers (these set-top boxes allow for HD on the Primary TV and SD on the secondary TV (TV2) without a secondary box on TV2), or
TiVo TiVo ( ) is a digital video recorder (DVR) developed and marketed by Xperi (previously by TiVo Corporation and TiVo Inc.) and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose fea ...
's Series 3 or HD recorders), or an HDTV-ready
HTPC A home theater PC (HTPC) or media center computer is a technological convergence, convergent device that combines some or all the capabilities of a personal computer with a software application that focuses on video, photo, audio playback, and ...
. Some cable boxes are capable of receiving or recording two or more broadcasts at a time in HDTV format, and HDTV programming, some included in the monthly cable service subscription price, some for an additional 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 to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in MPEG-2 format in a .ts file or in a Blu-ray-compatible format .m2ts file on the hard drive or DVD burner of a computer connected to the PVR through a USB 2.0 interface. More recent systems are able to record a broadcast high definition program in its 'as broadcast' format or transcode to a format more compatible with Blu-ray. 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. Set top box tuners with external storage support may be able to directly record the digital video stream itself, including additional data such as
teletext Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the to ...
. The set top box doesn't even need to support the audio and video encoding used, and the file recorded will be playable on any device that does support it. However encrypted content will require a receiver with the appropriate CAS setup. 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 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony a ...
(IEEE 1394) on request. None of the
direct broadcast satellite Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems ...
providers have offered this feature on any of their supported boxes, but some
cable TV Cable television is a system of delivering television broadcast programming, programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This ...
companies have. , boxes are not included in the FCC mandate. This content is protected by encryption known as 5C. This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all
fair use Fair use is a Legal doctrine, doctrine in United States law that permits limited use of copyrighted material without having to first acquire permission from the copyright holder. Fair use is one of the limitations to copyright intended to bal ...
of the content.


See also

*
Display motion blur In modern displays, motion blur is an unwanted artifact caused primarily by: # Retinal blur resulting from your eyes ''continuously'' tracking ''discrete'' movement. While your eyes move, the object you're tracking remains stationary throu ...
*
Glossary of video terms This glossary defines terms that are used in the documen"Defining Video Quality Requirements: A Guide for Public Safety" developed by thVideo Quality in Public Safety (VQIPS) Working Group It contains terminology and explanations of concepts relev ...
*
High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In compa ...
*
List of digital television deployments by country This is a list of digital television deployments by country, which summarises the process and progress of transition from analogue to digital broadcasting. The transition to digital television is a process that is happening at different paces ...
*
Optimum HDTV viewing distance Optimum HDTV viewing distance is the distance that provides the viewer with the optimum immersive visual HDTV experience. Background HDTV is designed to provide an experience more realistic than the television system it is designed to replace. ...
*
Ultra-high-definition television Ultra-high-definition television (also known as Ultra HD television, Ultra HD, UHDTV, UHD and Super Hi-Vision) today includes 4K resolution#Resolutions, 4K UHD and 8K resolution#Resolutions, 8K UHD, which are two digital video formats with an ...
(UHD or UHDTV)


References


Further reading

* Joel Brinkley (1997), ''Defining Vision: The Battle for the Future of Television'', New York: Harcourt Brace.
High Definition Television: The Creation, Development and Implementation of HDTV Technology
by Philip J. Cianci (McFarland & Company, 2012)
Technology, Television, and Competition
(New York: Cambridge University Press, 2004)


External links

History

the Italian HDTV experience from 1980s to 2006 in Italian C.R.I.T./RAI
The HDTV Archive Project
European adoption
Images formats for HDTV
article from the
EBU The European Broadcasting Union (EBU; , UER) is an alliance of Public broadcasting, public service media organisations in countries within the European Broadcasting Area (EBA) or who are member states of the Council of Europe, members of the ...
, Technical Review
High Definition for Europe a progressive approach
article from the
EBU The European Broadcasting Union (EBU; , UER) is an alliance of Public broadcasting, public service media organisations in countries within the European Broadcasting Area (EBA) or who are member states of the Council of Europe, members of the ...
, Technical Review
High Definition (HD) Image Formats for Television Production
technical report from the
EBU The European Broadcasting Union (EBU; , UER) is an alliance of Public broadcasting, public service media organisations in countries within the European Broadcasting Area (EBA) or who are member states of the Council of Europe, members of the ...
{{Authority control High-definition television Telecommunications-related introductions in 1936 Telecommunications-related introductions in 1990 ATSC Consumer electronics Digital television Television technology Television terminology