High-definition video or HD video refers to any video system of higher resolution than standard-definition (SD) video, and most commonly involves display resolutions of 1,280×720 pixels (720p) or 1,920×1,080 pixels (1080i/1080p). This article discusses the general concepts of high-definition video, as opposed to its specific applications in television broadcast (HDTV), video recording formats (HDCAM, HDCAM-SR, DVCPRO HD, D5 HD, AVC-Intra, XDCAM HD, HDV, and AVCHD), the Blu-ray Disc, and the D-VHS video tape format.

History[link]

1936–1980s[link]

From a historical perspective, the first electronic scanning format 405 lines was the first "high definition" television system as the previous mechanical systems had far fewer scanning lines.

From 1939, the US and other European countries experimented with 441 lines and 605 lines until the Federal Communications Commission (FCC) mandated 525 lines for the US from 1941. In wartime France, René Barthélemy experimented with higher definitions, reaching 1015 and even 1042 lines. Official French transmissions finally began with 819 lines from late 1949; however, this standard was abandoned in 1984 upon the adoption of 625-line colour on the TF1 network.

1980s[link]

Modern HD specifications date to the early 1970s, when Japanese engineers developed the HighVision 1,125-line interlaced TV standard (also called MUSE) that ran at 60 frames per second. The Sony HDVS system was presented at an international meeting of television engineers in Algiers, April 1981 and Japan's NHK presented its analog HDTV system at a Swiss conference in 1983.

The NHK system was standardized in the United States as Society of Motion Picture and Television Engineers (SMPTE) standard #240M in the early 1990s, but abandoned later on when it was replaced by a DVB analog standard. HighVision video is still usable for HDTV video interchange, but there is almost no equipment around to perform this function. Attempts at shoehorning in HighVision into a 6 MHz broadcast channel were mostly unsuccessful. All attempts at using this format for terrestrial TV transmission were forsaken by the mid-1990s.

The Europeans developed HD-MAC (1,250 lines, 50 Hz), a member of the MAC family of hybrid analogue/digital video standards; however, it never took off as a terrestrial video transmission format. HD-MAC was never designated for video interchange except by the European Broadcasting Union.

The current high-definition video standards in North America were developed during the course of the advanced television process initiated by the Federal Communications Commission in 1987 at the request of American broadcasters. In essence, the end of the 1980s was a death knell for most analog high definition technologies that had developed up to that time.

1990s[link]

The FCC process, led by the Advanced Television Systems Committee (ATSC) adopted a range of standards from interlaced 1,080-line video (a technical descendant of the original analog NHK 1125/30 Hz system) with a maximum frame rate of 30 Hz, and 720-line video, progressively scanned, with a maximum frame rate of 60 Hz.

In the end, however, the DVB standard of resolutions (1080, 720, 480) and respective frame rates (24, 25, 30) were adopted in conjunction with the Europeans that were also involved in the same standardization process. The FCC officially adopted the ATSC transmission standard (which included both HD and SD video standards) in 1996, with the first broadcasts on October 28, 1998.

2000s[link]

In the early 2000s, it looked as if DVB would be the video standard far into the future. However, both Brazil and China have adopted alternative standards for high-definition video^{[citation needed]} that preclude the interoperability that was hoped for after decades of largely non-interoperable analog TV broadcasting.

Technical details[link]

This chart shows the most common display resolutions, with the color of each resolution type indicating the display ratio (e.g., red indicates a 4:3 ratio)

High definition video (prerecorded and broadcast) is defined threefold, by:

• The number of lines in the vertical display resolution. High-definition television (HDTV) resolution is 1,080 or 720 lines. In contrast, regular digital television (DTV) is 480 lines (upon which NTSC is based, 480 visible scanlines out of 525) or 576 lines (upon which PAL/SECAM are based, 576 visible scanlines out of 625). However, since HD is broadcast digitally, its introduction sometimes coincides with the introduction of DTV. Additionally, current DVD quality is not high-definition, although the high-definition disc systems Blu-ray Disc and the defunct HD DVD are.
• The scanning system: progressive scanning (p) or interlaced scanning (i). Progressive scanning (p) redraws an image frame (all of its lines) when refreshing each image,for example 720p/1080p. Interlaced scanning (i) draws the image field every other line or "odd numbered" lines during the first image refresh operation, and then draws the remaining "even numbered" lines during a second refreshing, for example 1080i. Interlaced scanning yields greater image resolution if subject is not moving, but loses up to half of the resolution and suffers "combing" artifacts when subject is moving.
• The number of frames or fields per second (Hz). In Europe more common (50 Hz) television broadcasting system and in USA (60 Hz). The 720p60 format is 1,280 × 720 pixels, progressive encoding with 60 frames per second (60 Hz). The 1080i50 format is 1920 × 1080 pixels, interlaced encoding with 50 fields,(50 Hz) per second. Two interlaced fields formulate a single frame, because the two fields of one frame are temporally shifted. Frame pulldown and segmented frames are special techniques that allow transmitting full frames by means of interlaced video stream.

Often, the rate is inferred from the context, usually assumed to be either 50 Hz (Europe) or 60 Hz (USA), except for 1080p, which denotes 1080p24, 1080p25, and 1080p30, but also 1080p50 and 1080p60.

A frame or field rate can also be specified without a resolution. For example 24p means 24 progressive scan frames per second and 50i means 25 progressive frames per second, consisting of 50 interlaced fields per second. Most HDTV systems support some standard resolutions and frame or field rates. The most common are noted below. High-definition signals require a high-definition television or computer monitor in order to be viewed. High-definition video has an aspect ratio of 16:9 (1.78:1). The aspect ratio of regular widescreen film shot today is typically 1.85:1 or 2.39:1 (sometimes traditionally quoted at 2.35:1). Standard-definition television (SDTV) has a 4:3 (1.33:1) aspect ratio, although in recent years many broadcasters have transmitted programs "squeezed" horizontally in 16:9 anamorphic format, in hopes that the viewer has a 16:9 set which stretches the image out to normal-looking proportions, or a set which "squishes" the image vertically to present a "letterbox" view of the image, again with correct proportions.

Common high-definition video modes[link]

Extra high-definition video modes[link]

Note: ¹ Image is either a frame or, in case of interlaced scanning, two fields. (EVEN and ODD)

HD content[link]

High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, high definition disc (BD), digital cameras, internet downloads and the latest generation of video game consoles.

• Most computers are capable of HD or higher resolutions over VGA, DVI, and/or HDMI.
• The optical disc standard Blu-ray Disc can provide enough digital storage to store hours of HD video content. DVDs look best on screens that are smaller than 36 inches (91 cm), so they are not always up to the challenge of today's high-definition (HD) sets. Storing and playing HD movies requires a disc that holds more information, like a Blu-ray Disc.^{[citation needed]}

Types of recorded media[link]

The high resolution photographic film used for cinema projection is exposed at the rate of 24 frames per second but usually projected at 48, each frame getting projected twice helping to minimise flicker. One exception to this was the 1986 National Film Board of Canada short film Momentum, which briefly experimented with both filming and projecting at 48 frame/s, in a process known as IMAX HD.

Depending upon available bandwidth and the amount of detail and movement in the image, the optimum format for video transfer is either 720p24 or 1080p24. When shown on television in PAL system countries, film must be projected at the rate of 25 frames per second by accelerating it by 4.1 percent. In NTSC standard countries, the projection rate is 30 frames per second, using a technique called 3:2 pull-down. One film frame 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) and then the process is repeated, thus achieving the correct film projection rate with two film frames shown in 1/12 of a second.

Older (pre-HDTV) recordings on video tape such as Betacam SP are often either in the form 480i60 or 576i50. These may be upconverted to a higher resolution format (720i), but removing the interlace to match the common 720p format may distort the picture or require filtering which actually reduces the resolution of the final output.

Non-cinematic HDTV video recordings are recorded in either the 720p or the 1080i format. The format used is set by the broadcaster (if for television broadcast). In general, 720p is more accurate with fast action, because it progressively scans frames, instead of the 1080i, which uses interlaced fields and thus might degrade the resolution of fast images.

720p is used more for Internet distribution of high-definition video, because computer monitors progressively scan; 720p video has lower storage-decoding requirements than either the 1080i or the 1080p. This is also the medium for high-definition broadcasts around the world and 1080p is used for Blu-ray movies.

HD in filmmaking[link]

Film as a medium has inherent limitations, such as difficulty of viewing footage while recording, and suffers other problems, caused by poor film development/processing, or poor monitoring systems. Given that there is increasing use of computer-generated or computer-altered imagery in movies, and that editing picture sequences is often done digitally, some directors have shot their movies using the HD format via high-end digital video cameras. While the quality of HD video is very high compared to SD video, and offers improved signal/noise ratios against comparable sensitivity film, film remains able to resolve more image detail than current HD video formats. In addition some films have a wider dynamic range (ability to resolve extremes of dark and light areas in a scene) than even the best HD cameras. Thus the most persuasive arguments for the use of HD are currently cost savings on film stock and the ease of transfer to editing systems for special effects.

Depending on the year and format a movie was filmed in, the exposed image can vary greatly in size. Sizes range from as big as 24 mm × 36 mm for VistaVision/Technirama 8 perforation cameras (same as 35 mm still photo film) going down through 18 mm × 24 mm for Silent Films or Full Frame 4 perforations cameras to as small as 9 mm × 21 mm in Academy Sound Aperture cameras modified for the Techniscope 2 perforation format. Movies are also produced using other film gauges, including 70 mm films (22 mm × 48 mm) or the rarely used 55 mm and CINERAMA.

The four major film formats provide pixel resolutions (calculated from pixels per millimeter) roughly as follows:

• Academy Sound (Sound movies before 1955): 15 mm × 21 mm (1.375) = 2,160 × 2,970
• Academy camera US Widescreen: 11 mm × 21 mm (1.85) = 1,605 × 2,970
• Current Anamorphic Panavision ("Scope"): 17.5 mm × 21 mm (2.39) = 2,485 × 2,970
• Super-35 for Anamorphic prints: 10 mm × 24 mm (2.39) = 1,420 × 3,390

In the process of making prints for exhibition, this negative is copied onto other film (negative → interpositive → internegative → print) causing the resolution to be reduced with each emulsion copying step and when the image passes through a lens (for example, on a projector). In many cases, the resolution can be reduced down to 1/6 of the original negative's resolution (or worse).^{[citation needed]} Note that resolution values for 70 mm film are higher than those listed above.

HD on the World Wide Web/HD Streaming[link]

A number of online video streaming/on demand and digital download services offer HD video, among them YouTube, Vimeo, Hulu, Amazon Video On Demand, Netflix Watch Instantly, and others. Due to heavy compression, the image detail produced by these formats are far below that of broadcast HD, and often even inferior to DVD-Video (3-9 Mbit/s MP2) upscaled to the same image size.^[1] The following is a chart of numerous online services and their HD offering:

World Wide Web HD resolutions[link]

HD in video surveillance[link]

High definition (HD) video is now the norm in the surveillance industry as an increasing number of manufacturers of security cameras now claim to offer HD cameras. It is understandable since the need for high resolution, colour fidelity, and frame rate is more acute for surveillance purposes to ensure that the quality of the video output is of an acceptable standard that can be used both for preventative surveillance as well as for evidence purposes.

HD in video gaming[link]

The PlayStation 3 game console can output to native 1080p through both component and HDMI cables. The Xbox 360 can output 1080p over HDMI but games can only run at 720p upscaled to 1080p. The Wii can output up to 480p (enhanced-definition) over component, which while not technically HD, is very useful for HDTVs as it avoids de-interlacing artifacts. The Wii can also output 576i in PAL regions.

Native 1080p produces a sharper and clearer picture compared to upscaled 1080p. Besides increasing the visual quality of games, users can also download HD movies and video clips from the PlayStation Network or Xbox Live Marketplace services to their respective consoles. The PlayStation 3 can also play Blu-ray Discs which hold HD data.

Though only a handful of games available have the native resolution of 1080p, all games on the Xbox 360 and PlayStation 3 can be upscaled up to this resolution. Xbox 360 and PlayStation 3 games are labeled with the output resolution on the back of their packaging, although on Xbox 360 this indicates the resolution it will upscale to, not the native resolution of the game. Also, as the Xbox 360 did not originally support 1080p (it did not have an HDMI port), earlier games that said 720p on the box can now be upscaled to 1080p.

An increasing number of PC games can be rendered in 1,920×1,080 or higher.

The PlayStation 2 and the original Xbox had HD support, but few games of that era took advantage of this feature. The original Xbox however only had HD support enabled in NTSC regions.

Nintendo's new console, the Wii U, supports HD.

See also[link]

Blu-ray portal

• ATSC tuner
• Digital Video Broadcasting (DVB)
• DTV channel protection ratios
• United States Federal Standard 1037C
• HD ready
• Integrated Services Digital Broadcasting
• Ultra High Definition Television
• Waveform monitor
• HDTV input and colorspace (YPbPr/YCbCr).

References[link]

Further reading[link]

• Images formats for HDTVPDF (549 KiB), article from the EBU Technical Review .
• High Definition for Europe - a progressive approachPDF (207 KiB), article from the EBU Technical Review .
• High Definition (HD) Image Formats for Television ProductionPDF (117 KiB), technical report from the EBU
• Digital Terrestrial HDTV Broadcasting in EuropePDF, technical report from the EBU

External links[link]

Look up HDTV in Wiktionary, the free dictionary.

Wikiquote has a collection of quotations related to: High-definition video

• ATSC

Zhang Jike
Personal information
Full name	ZHANG Jike
Nationality	China
Playing style	Right-handed, shakehand grip
Highest ranking	1 (June 2012)[1]
Born	(1988-02-16) February 16, 1988 (age 24)[2] Qingdao, Shandong, China
Height	1.75 m (5 ft 9 in)
Weight	70 kg (150 lb; 11 st)
Medal record Men's table tennis Competitor for  China World Championships Gold 2012 Dortmund Team Gold 2011 Rotterdam Singles Bronze 2011 Rotterdam Doubles Gold 2010 Moscow Team Bronze 2009 Yokohama Doubles Silver 2009 Yokohama Mixed Doubles World Cup Gold 2011 Paris Singles Silver 2010 Magdeburg Singles Gold 2010 Dubai Team Gold 2009 Linz Team Asian Championships Silver 2009 Lucknow Singles Silver 2009 Lucknow Doubles Silver 2009 Lucknow Mixed Doubles Gold 2009 Lucknow Team

Zhang Jike (simplified Chinese: 张继科; traditional Chinese: 張繼科; pinyin: Zhāng Jì Kē; born February 16, 1988 in Qingdao, Shandong, China) is a Chinese table tennis player.^[2][3]

Zhang Jike is the reigning World Champion and World Cup winner in singles. Should he win the Olympic gold medal in singles, he will be the fourth male player in the history of table tennis to achieve a career grand slam.

Equipment[link]

Zhang Jike currently uses a Butterfly Viscaria FL blade with a black DHS Neo Hurricane III National Version (Blue Sponge) for his forehand and a red Butterfly Tenergy 64 for his backhand.

Butterfly introduced in 2011 a new blade in his name. Though the blade is designed for Zhang, he has not used it so far.

Career records[link]

Singles (as of December 6, 2011)^[3]

• World Championships: winner (2011)
• Men's World Cup: winner (2011); runner-up (2010).
• Pro Tour winner (3): China Open, Suzhou (2010); German Open (2011); Slovenian Open (2012). Runner-up (3): Qatar Open (2010); China Open, Suzhou (2011); Austrian Open (2011).
• Pro Tour Grand Finals appearances: 2. Record: runner-up (2011); SF (2009).
• Asian Championships: Runner-up (2): 2009; 2012.
• Asian Cup: winner (2010).

Men's Doubles

• World Championships: semi-final (2009, 11).
• Pro Tour winner (6): Kuwait Open 2010; Slovenian, English, UAE, German, China (Suzhou) Open 2011.
  Runner-up (7): Kuwait, Qatar Open 2008; China (Suzhou) Open 2009; German Open 2010; Qatar, China (Shenzen), Austrian Open 2011.
• Pro Tour Grand Finals: winner (2011).
• Asian Games: winner (2010).

Mixed Doubles

• World Championships: runner-up (2009).
• Asian Games: QF (2010).
• Asian Championships: runner-up (2009).

Team

• World Championships: winner (2010).
• World Team Cup: winner (2009, 10).
• Asian Games: winner (2010).
• Asian Championships: winner (2009).

See Also[link]

• List of table tennis players

References[link]

This biographical article relating to a People's Republic of China table tennis figure is a stub. You can help Wikipedia by expanding it. v t e

Xu Xin
Personal information
Nationality	China
Playing style	Left-handed, penhold grip
Equipment(s)	Stiga
Highest ranking	4 (March 2012)[1]
Born	(1990-01-08) January 8, 1990 (age 22)[2] Jiangsu, China
Height	1.81 m (5 ft 11 1⁄2 in)
Weight	75 kg (170 lb; 11.8 st)
Medal record Men's table tennis Competitor for  China World Championships Gold 2012 Dortmund Team Gold 2011 Rotterdam Doubles Gold 2010 Moscow Team Silver 2009 Yokohama Doubles World Cup Gold 2011 Magdeburg Team Gold 2010 Dubai Team Gold 2009 Linz Team Universiade Gold 2011 Shenzhen Team Gold 2011 Shenzhen Doubles Gold 2011 Shenzhen Singles

Xu Xin (simplified Chinese: 许昕; traditional Chinese: 許昕; pinyin: Xǔ Xīn; born January 8, 1990 in Jiangsu, China) is a Chinese table tennis player.^[2]

Equipment[link]

He uses a blade Stiga Rosewood V, and in his forehand a Hurricane III (Blue sponge) and a Tenergy 64 in his backhand.

Career records[link]

Singles (as of May 20, 2012)^[3]

• World Championships: round of 16 (2011).
• World Tour winner (×4): Kuwait Open 2010; Slovenian, Qatar Open 2011; Qatar Open 2012.
  Runner-up (×1): Belarus Open 2008; Korea Open 2012
• World Tour Grand Finals appearances: 2. Record: runner-up (2009).
• Asian Championships: SF (2009, 12).
• Asian Cup: 2nd (2011); 3rd (2010).

Men's Doubles

• World Championships: winner (2011); runner-up (2009).
• World Tour winner (×7): Slovenian, Danish, Qatar Open 2009; China Open 2010; English, Qatar Open 2011; Qatar Open 2012.
  Runner-up (×6): China (Suzhou) Open 2009; Qatar, Kuwait Open 2010; UAE Open 2011; Hungarian, Slovenian Open 2012.
• Asian Games: runner-up (2010).
• Asian Championships: winner (2009).

Mixed Doubles

• World Championships: QF (2009).
• Asian Games: winner (2010).
• Asian Championships: winner (2012), SF (2009).

Team

• World Championships: winner (2012).
• World Championships: winner (2010).
• World Team Cup: winner (2009, 10, 11).
• Asian Games: winner (2010).
• Asian Championships: winner (2009, 12).

References[link]

Wikimedia Commons has media related to: Xu Xin

This biographical article relating to a People's Republic of China table tennis figure is a stub. You can help Wikipedia by expanding it. v t e