Devoted to High Definition Television
This website is devoted to informing you about high-definition television and the latest trends, developments, upgrades and features for HDTV.
To begin want to give you background high-definition television and the various terms surrounding HDTV. When thinking about HDTV it is important to start with the history of high-definition television and a definition of what exactly HDTV is as many people are often confused at the term HDTV.
HDTV (or HDTV) video that has a much higher resolution than traditional television systems (standard definition television or SDTV or SD). HDTV has one or two million pixels per image, about five times that of SD. At the start of HDTV transmission used analogue techniques, the goal is now HDTV broadcast compressed digital video.
History of HDTV
More information: Analog high-definition television system and television history
On November 2, 1936, the BBC broadcast the world began the first regular public high-definition service from Alexandra Palace in north London Victorian. And claims to be the birthplace of television as we know it today.
The term high definition oz described a series of television systems, from the late 1930s, however, systems theory were only high definition compared to earlier systems that rely on mechanical systems that have as little only 30 lines of resolution.
The service for HDTV UK began testing in August 1936 and regular communication with the November 1936 using only the (mechanical) and Baird 240-line (electronic) Marconi-EMI 405 line (377i) system. The Baird system was discontinued in February 1937. In 1938, France followed its own system with 441 lines, versions of which are also used by a number of other countries. U. S. NTSC joined in 1941. Introduced in France in 1949 years, even higher standard resolution is 819 lines (768I), a system that is still in high definition with the current data are only for mono. All these systems use striping and a ratio of 4:03, except the system of 240 lines progressive (actually said at the time with the appropriate technical term “sequential”) and 405-line system, which began as 5:04 ET later changed to 4:03. The 405-line system was the idea (then) revolutionary interlaced to overcome the problem of flicker in line with the frame rate of 240 to 25 Hz line 240 ICT could double the frame rate would mean that it was transmitted to the signal bandwidth is doubled, which is unacceptable.
Color emissions were also higher resolution, first in the American NTSC color in 1953, which was compatible with systems from B & W earlier why If Sami and 525 lines (480i) resolution. He followed European standards until mid-1960, PAL and SECAM systems when added to the monochrome 625 line (576i) transmissions.
Following formal approval (DVB) widescreen modes on digital TV HDTV in early 2000 is the 525-line NTSC (or PAL-M) systems and the European Union 625-line PAL and SECAM are now considered standard for HDTV systems. In Australia, the digital system of 625 lines progressive (with 576 active lines) is officially recognized as high definition.
Analog systems
In 1949, France began a year with 819 lines in the transmission system (768I). It was monochrome only, used only for VHF is the first French television channel, and ceased in 1985.
In 1958, the Soviet Union developed Тransformator, the first high definition television system (definition) capable of producing an image composed of 1125 lines of resolution to provide teleconferencing for the military administration. He was a research program and the system never developed in the military or broadcasting.
In 1979, the first state broadcaster NHK Japanese consumer Developed HDTV with a screen aspect ratio of 5:03. The system, known as Hi-Vision or MUSE multiple sub-After consolidation of the Nyquist sampling ICT signal coding requires about twice the bandwidth of the NTSC system designed around existing furnace provided both the resolution (1080i / 1125 lines). Satellite tests began in 1989, with regular monitoring began in 1991 and regular transmission of the SB-9hp started November 25, 1994, which had the NHK and commercial programming.
In 1981, the MUSE system is demonstrated for the first time in the United States, using the same ratio of 5:03 as the Japanese system.6 During a visit to a demonstration of Muse in Washington, U. S. President Ronald Reagan was impressed and has officially declared that “a national issue” for HDTV to introduce USA.7
Many proposed systems, as the new standard for the United States, including the Japanese MUSE system, all designed by the FCC rejected because of the high bandwidth requirements. Currently, the number of channels and fast growing IT was already a problem of bandwidth. A new standard should be more efficient, less bandwidth needed for HDTV existing NTSC.
Disappearance of analogue HD
Standardization of HDTV analog limited in the 1990s Twilight Breaking Dawn Streaming Megavideo has not led to the global adoption of HDTV as one of the technical and economic reasons during the period can not use the HDTV bandwidth wider than normal television.
At first HDTV commercial experiments such moments oven NHK MUSE more than the required bandwidth of a standard definition broadcast and HD-MAC was not much better. Despite efforts to reduce analog HDTV about 2 times the bandwidth of the thesis Television SDTV format was still only distributable by satellite.
n addition, time recording and playback of HDTV signal important technical challenge was the first year of high definition television (Sony HDVS). Japan remained the only country in public successes of analogue broadcasting HDTV, with seven television stations that share a single channel. Digital HDTV began in Japan in 2000, and the analog service ended in the early morning hours of October 1, 2007.
Rise of digital compression
Since 1972, the radio sector of the International Telecommunication Union (ITU-R)-working to create an overall recommendation for HDTV analog. But not the thesis of recommendations made in the broadcasting bands that can reach residential users. The standardization of MPEG-1 in 1993 led to the acceptance of the organization aussi Recommendations ITU-R BT.709.8 Meanwhile the thesis standard Digital Video Broadcasting (DVB) formed a coalition of broadcasters, manufacturers electronics and regulators. The developer and DVB Chartered although typically the standard ETSI.9
DVB has created the first model for the DVB-S digital satellite, DVB-C digital cable TV and DVB-T digital terrestrial TV. Fee system theory, can be used for both SDTV and HDTV. The Grand Alliance proposed by the United States as the new standard for ATSC HDTV and SDTV. Both ATSC and DVB-based MPEG-2 standard. DVB-S2 is based on newer, more efficient compression standard H.264/MPEG-4 AVC. Common to all DVB standards are the use of highly efficient modulation techniques to further reduce bandwidth, especially to reduce material requirements and receiver antenna.
In 1983, the radio sector of the International Telecommunications Union International Telecommunication Union (ITU-R) has created a working group (IWP11 / 6) to establish a single international HDTV standard. One of the thorniest issues concerned a suitable frame / field refresh rate, the world has already split into two camps, 25/50 Hz and 30/60 Hz, associated with the image of stability of the reasons for the frequency of main electrical supply.
The group IWP11 / 6 reported that work in many ways and in the 1980s he served as a basis to encourage the development of a series of digital video processing zones, if for no other conversation between the two main frame / field motion vectors using the rates leading to developments in other areas. While a large HDTV standard was not the end ESTABLISHED, an agreement on the aspect ratio was achieved.
Initially, the aspect ratio of 5:03 were the existing candidate primary target, because of the influence of the cinema big screen, the ratio of 16:9 (1.78) Finally, you have accumulated a reasonable compromise between 5.3 (1.67) and 1.85 common film in widescreen. (Bob Morris explained that the ratio of 4:09 p.m. has been chosen as the geometric mean of Being Academy ratio 4:3 and 2.4:1, the large format film in common use to minimize waste of space screen to display content in the various aspects ratios.
A ratio of 16:9, duly agreed at the first meeting of IWP11 / 6 Working in the survey for the BBC and the development of installation Kingswood Warren. The resulting recommendation ITU-R ITU-R BT.709-2 (“Rec. 709″) includes the 16:9 format, a particular colorimetry, and analysis of 1080i (interlaced lines actively resolution 1080) and 1080p (1.080 Gradually scan lines). The UK DTT HD trial MBAFF used, the contents of both progressive and interlaced on the same encoding.
Also includes the alternative 1440 x 1152 HDMAC format scanning. (According to reports, a controversial line 750 (720p) (720 lines progressive scan) was considered by the ITU few years have enhanced the form of television, not a true HD format, and is 11 not included, although 1920 × 1280 × 1080i and 720p systems for a wide range of frame rates and the field was defined by the SMPTE MANY U.S..)
HDTV inaugural United States
Insert HDTV technology in the United States in the 1990s by the Digital HDTV Grand Alliance, a group of television, electronic equipment, telecommunications and the Massachusetts Institute of Technology.1213 field trials of HDTV in 199 places United States was completed on August 14 1994.14 HDTV first time in public in the United States occurred in July 23, 1996, when the Raleigh, North Carolina television station WRAL-HD began broadcasting from the around the existing WRAL-TV Southeast Raleigh, winning a race to be the first model of HD station in Washington, DC, which began broadcasting July 31, 1996 with the distinctive WHD-TV, based on facilities owned and operated NBC station WRC-TV The U. 0.151617 S. Advanced Television Systems Committee (ATSC) HDTV system was the first public appearance Oct. 29, 1998, during the live coverage of astronaut John Glenn returned to space mission aboard the space shuttle Discovery.18 The signal transmitted to coast to coast, and seen by the public in science centers, theaters and other public specially equipped to receive and display broadcast.1819
European HDTV
While HDTV has been shown in Europe since the early 1990s, the first regular broadcasts began on January 1, 2004, when the Belgian company Euro1080 HD1 launched the chain with the traditional New Year’s Concert in Vienna. Test transmission was active since the report of the IBC in September 2003, Day of New Year’s goal marked the official start of the broadcast channel HD1, and the start of HDTV in Europe .20
Euro1080, some television channels of HDTV service Belgian company Alfacam to break the deadlock in the pan “means no HD programming HDTV Buy HD broadcasting means that …” and stimulate interest HDTV channel HD1 Europe.21 The original free-to-air and consist primarily of sports, theater, music and other cultural events are broadcast on a multilingual soundtrack has become a rolling program of 4 or 5 hours a day.
First thesis European broadcasting HDTV 1080i format uses MPEG-2 is a DVB-S from SES Astra 1H satellite. Euro1080 broadcasting later changed to compression was MPEG-4/AVC DVB-S2 signal according to the channel that broadcast later in Europe.
The number of European viewers and HD channel has grown steadily since its first annual survey HDTV monitor market for SES Astra Satellite 2010 Over 200 reports commercial channels broadcast in high definition satellite Astra, the 185 million TV-HD Ready sold in Europe (60 million pounds in 2010 alone), and 20 million households (27% of all European digital satellite TV households) watching HD satellite transmissions (via satellite Astra 16 million) 0.22
In December 2009 the UK became the first European country to develop the digital terrestrial high definition television is happy (under the brand DVB-T), using the new transmission standard DVB-T2, as defined in the group Digital Television (DTG) D-book. DTT HD service currently has four HD channels and is now distributed by region in the UK, according to the digital switchover. Some issuers such as the Crystal Palace transmitter Freeview HD broadcasting service before the transition to digital through a temporary, low-power pre-DSO multiplex.
Notation
HDTV transmission systems coincides with three important parameters:
• The image size in pixels, as the number of horizontal pixels is designated x number of vertical pixels, for example, 720 or 1280 × 1920 × 1080. Often, the number of horizontal pixels is implied by the context and omitted, as in the case of 720p and 1080p.
• Scan the system coincides with the letter P for progressive scan or interlaced for i.
• Refresh rate is defined as the number of frames per second. For alternative systems interwoven year Specify the number of frames per second often requires used.citation
If the three parameters used as described in the following form: frame or field gold systemframe sizescanning rate system.citation frame size / frame or field ratescanning often needs the frame size or frame rate may be abandoned if the value of the implicit part. In this case, the parameter is specified numeric Staying in first, followed by the scanning system.
For example, 1920 × 1080p25 progressive scan identified with 25 frames per second, each part being the width 1.920 1.080 pixels pixels and height. 1080i25 or 1080i50 notation identifies interlaced scanning format with 25 frames (50 fields) per second, each frame being 1080 pixels wide by 1920 pixels high.citation 1080i30 1080i60 and scoring requires interlaced format is identical to 30 images ( 60 fields) per second, are all 1920 pixels wide and 1080 pixels in high.citation required 720p60 notation identifies progressive scanning at 60 frames per second, each frame being 720 pixels high and 1280 pixels horizontally is implied.
Three systems of 50 Hz over scan rates: 25, 25p and 50p. 60 Hz systems support a wider range of frame rates: 23.976, 24p, 29.97i/59.94i, 29.97p, 30p, 59.94p and 60 minutes. In the days of standard definition television, the fractional rates were often rounded to integers, for example 23.976 was often 24p, 60i and 59.94i was often called. Media 60 Hz HDTV both fractional and absolute rates differ slightly, so the use of strict notation is needed to avoid ambiguity. However, almost universally called 29.97i/59.94i 60i, p 23.976 24p.citation even be called
The name of the commercial product, the frame rate is often dropped and am implied by the context (eg a TV 1080i). A rate can be without a specific resolution. For example, 24 means clustering 24p frames per second progressive scan, and 50i interlaced at 25 frames per media second.23
There is no standard for HDTV color support. Until recently, the pixel color of each governed by three color values to 8 bits, each representing the standard red, blue, green, and which defines a color of a pixel.
• 23 976 Hz (at the rate of film compatible NTSC standard clock speed)
• 24 Hz (international film and High Definition ATSC material)
• 25 Hz (PAL, SECAM standard definition movie in high definition material)
• 29.97 Hz (NTSC standard material)
• 50 Hz (PAL & SECAM HD material)
• 59.94 Hz (ATSC material-High Definition)
• 60 Hz (ATSC material-High Definition)
• 120 Hz (ATSC material-High Definition)
At least, HDTV has twice the linear resolution of standard TV (SDTV), thus showing more detail than analog TV or standard DVD. Technical standards for broadcasting HDTV also handle the 16:09 aspect ratio pictures without using letterboxing or anamorphic stretching, thus increasing the effective image resolution.
Optimal format for transmission depends on the type of videographic recording medium used in the properties of the image. Volume and rate should be the origin and resolution. Very high resolution source may require more bandwidth is available to be transmitted without losing credibility. Lossy compression used to store any digital HDTV transmission systems distort the image received from uncompressed.
There is confusion commonly use terms PAL, SECAM and NTSC, referring to HD material. These conditions apply only to a standard TV, not HD. The only technical reason to keep the pace as 25 Hz in PAL HD frame is to maintain compatibility between the systems HD and HDTV standard.
Media Types
35 mm film standard film projection used a much higher image resolution HDTV systems, and is exposed to irradiated at a rate of 24 frames per second (frame / s). To be broadcast standard TV, PAL-system countries, film is scanned at a rate of 25 frames Television / s, resulting in an acceleration of 4.1 percent, which is considered generally acceptable. NTSC-system countries, the TV scan rate of 30 frames / s would bring considerable acceleration if the same were attempted, and the remedy is performed by a technique called drop-down 03:02: All pair of consecutive images the film is held for three field video (1 / 20 of a second) and the next day was held for two field video (1 / 30 of a second), providing air time for two frames 1 / 12 that of a second and reach the average of the film in context.
Non-cinematic HDTV video recordings intended for broadcast are recorded usually 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet video broadcasting high-definition, because most computer monitors operate in progressive scan. 720p requires both the storage and decoding requirements adopted less than two 1080i and 1080p. Frame 1080p 24 frames / s and 1080i-30 / s is typically used on Blu-Ray, in 2011, yet there is no record that can support 1080p, 60 frames / s.
Contemporary systems
Besides equipment, HDTV-Ready others may be needed to view HDTV. United States, cable ready televisions can display HD content without using an external box. They have a built in QAM tuner and / or a slot for adding CableCARD.24
Sources include high-definition picture terrestrial broadcast, direct broadcast satellite, digital cable, IPTV, high definition video Blu-ray Disc (BD), Internet downloads. Sony Playstation 3 has an extensive HD compatible for Blu-ray platform, the fact that the Xbox 360 from Microsoft with the addition of Netflix streaming capabilities and Zune Marketplace, where users can rent or buy digital HD content.25 HD consoles can affect how developers port games from past consoles, PS3 and 360, often with remastered graphics.
Recording Compression
HDTV can be recorded on the D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), Digital Video Recorder HDTV compatible (eg DirecTV HD DVR, Sky HD set-top box, a VIP or VIP 622 Dish Network 722 HD digital video recorder receivers, or TiVo Series 3 or HD recorders), or HD-ready HTPC. number of cable boxes can receive or record two or more programs simultaneously and HDTV Programming HDTV, some free, cost, can be read with Cable firm’s application.
Enormous amount of data storage required to archive uncompressed streams means cheaper storage options are not available compressed in the consumer market until recently. In 2008, Personal Video Recorder Hauppauge 1212 was presented. This device accepts HD content via component video inputs and stores the content transport stream MPEG compressed (. TS) file format, or Blu-ray. M2TS files on your hard drive or DVD burner to your computer via USB 2.0 interface for PVR.
MPEG-2 real-time signal compression of an uncompressed digital HDTV prohibitive for the consumer market right now, but you have to be expensive a few years (if it is more relevant for consumer HD camcorders that record HDTV). Analog recording with bandwidth capable of recording analog HD, such as W-VHS is no longer produced for the consumer market are costly rare in the secondary market.
United States, as part of the FCC connection and play agreement, cable companies are required to provide clients with rent HD set-top converters with “functional” Firewire (IEEE 1394) on request. None of the suppliers of direct broadcast satellites offered this feature on all of their supported boxes, but some cable TV companies have. In July 2004, boxes are not included in the mandate of the FCC. This content is protected by encryption known as 5C.26 This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively preventing most if not all fair use content.
