1080i (also known as Full HD or BT.709) is an abbreviation referring to a combination of frame resolution and scan type, used in high-definition television (HDTV) and high-definition video. The number "1080" refers to the number of horizontal lines on the screen. The "i" is an abbreviation for "interlaced"; this indicates that only the odd lines, then the even lines of each frame (each image called a video field) are drawn alternately, so that only half the number of actual image frames are used to produce video. A related display resolution is 1080p, which also has 1080 lines of resolution; the "p" refers to progressive scan, which indicates that the lines of resolution for each frame are "drawn" in on the screen sequence.

The term assumes a widescreen aspect ratio of 16:9 (a rectangular TV that is wider than it is tall), so the 1080 lines of vertical resolution implies 1920 columns of horizontal resolution, or 1920 pixels × 1080 lines. A 1920 pixels × 1080 lines screen has a total of 2.1 megapixels (2.1 million pixels) and a temporal resolution of 50 or 60 interlaced fields per second. This format is used in the SMPTE 292M standard.

The choice of 1080 lines originates with Charles Poynton, who in the early 1990s pushed for "square pixels" to be used in HD video formats.[1]

Broadcast standard

Interlaced video frame (car wheel)
An example frame of poorly deinterlaced video. Despite the fact that most TV transmissions are interlaced, plasma and LCD display technologies are progressively scanned. Consequently, flat-panel TVs convert an interlaced source to progressive scan for display, which can have an adverse impact on motion portrayal.

Within the designation "1080i", the i stands for interlaced scan. A frame of 1080i video consists of two sequential fields of 1920 horizontal and 540 vertical pixels. The first field consists of all odd-numbered TV lines and the second all even numbered lines. Consequently, the horizontal lines of pixels in each field are captured and displayed with a one-line vertical gap between them, so the lines of the next field can be interlaced between them, resulting in 1080 total lines. 1080i differs from 1080p, where the p stands for progressive scan, where all lines in a frame are captured at the same time. In native or pure 1080i, the two fields of a frame correspond to different instants (points in time), so motion portrayal is good (50 or 60 motion phases/second). This is true for interlaced video in general and can be easily observed in still images taken of fast motion scenes. However, when 1080p material is captured at 25 or 30 frames/second, it is converted to 1080i at 50 or 60 fields/second, respectively, for processing or broadcasting. In this situation both fields in a frame do correspond to the same instant. The field-to-instant relation is somewhat more complex for the case of 1080p at 24 frames/second converted to 1080i at 60 fields/second.

The field rate of 1080i is typically 60 Hz (i.e., 60 fields per second) for countries that use or used System M (NTSC and Brazilian PAL-M) as analog television system with 60 fields/sec (such as United States, Canada, Mexico, Japan, South Korea, Taiwan and Philippines), or 50 Hz for regions that use or used 625-lines (PAL or SECAM) television system with 50 fields/sec (such as most of Europe, most of Africa, China, India, Australia, New Zealand, Middle East, and others). Both field rates can be carried by major digital television broadcast formats such as ATSC, DVB, and ISDB-T International. The frame rate can be implied by the context, while the field rate is generally specified after the letter i, such as "1080i60". In this case 1080i60 refers to 60 fields per second. The European Broadcasting Union (EBU) prefers to use the resolution and frame rate (not field rate) separated by a slash, as in 1080i/30 and 1080i/25, likewise 480i/30 and 576i/25.[2] Resolutions of 1080i60 or 1080i50 often refers to 1080i/30 or 1080i/25 in EBU notation.

1080i is directly compatible with some CRT HDTVs on which it can be displayed natively in interlaced form, but for display on progressive-scan—e.g., most new LCD and plasma TVs, it must be deinterlaced. Depending on the television's video processing capabilities, the resulting video quality may vary, but may not necessarily suffer. For example, film material at 25fps may be deinterlaced from 1080i50 to restore a full 1080p resolution at the original frame rate without any loss. Preferably video material with 50 or 60 motion phases/second is to be converted to 50p or 60p before display.

Worldwide, most HD channels on satellite and cable broadcast in 1080i. In the United States, 1080i is the preferred format for most broadcasters, with Discovery Communications, Viacom, Time Warner, Comcast owned networks broadcasting in the format; along with most smaller broadcasters. Only 21st Century Fox-owned television networks and Disney-owned television networks, along with MLB Network and a few other cable networks use 720p as the preferred format for their networks; A+E Networks channels converted from 720p to 1080i sometime in 2013 due to acquired networks already transmitting in the 1080i format. Many ABC affiliates owned by Hearst Television and former Belo Corporation stations owned by TEGNA, along with some individual affiliates of those three networks, air their signals in 1080i and upscale network programming for master control and transmission purposes, as most syndicated programming and advertising is produced and distributed in 1080i, removing a downscaling step to 720p. This also allows local newscasts on these ABC affiliates to be produced in the higher resolution (especially for weather forecasting presentation purposes for map clarity) to match the picture quality of their 1080i competitors.

Some cameras and broadcast systems that use 1080 vertical lines per frame do not actually use the full 1920 pixels of a nominal 1080i picture for image capture and encoding. Common subsampling ratios include 3/4 (resulting in 1440x1080i frame resolution) and 1/2 (resulting in 960x1080i frame resolution). Where used, the lower horizontal resolution is scaled to capture and/or display a full-sized picture. Using half horizontal resolution and only one field of each frame (possibly with added anti-alias filtering or progressive capture) results in the format known as qHD, which has frame resolution 960x540 and 30 or 25 frames per second. Due to the chosen 16x16 pixel size for a compressed video packet known as a macroblock as used in ITU H.261 to H.264 video standards, a 1080-line video must be encoded as 1088 lines and cropped to 1080 by the de-compressor. The 720-line video format divides perfectly by 16 and therefore does not require any lines to be wasted.

See also


  1. ^ Poynton, Charles. "Charles Poynton – square pixels and 1080". Retrieved 2013-02-21.
  2. ^ "High Definition (HD) Image Formats for Television Production," EBU-TECH 3299, EBU.UER, Geneva, January 2010, page 7

External links


576p is the shorthand name for a video display resolution. The p stands for progressive scan, i.e. non-interlaced, the 576 for a vertical resolution of 576 pixels, usually with a horizontal resolution of 720 or 704 pixels. The frame rate can be given explicitly after the letter.


720p (1280×720 px; also called HD Ready or standard HD) is a progressive HDTV signal format with 720 horizontal lines and an aspect ratio (AR) of 16:9, normally known as widescreen HDTV (1.78:1). All major HDTV broadcasting standards (such as SMPTE 292M) include a 720p format, which has a resolution of 1280×720; however, there are other formats, including HDV Playback and AVCHD for camcorders, that use 720p images with the standard HDTV resolution. The frame rate is standards-dependent, and for conventional broadcasting appears in 50 progressive frames per second in former PAL/SECAM countries (Europe, Australia, others), and 59.94 frames per second in former NTSC countries (North America, Japan, Brazil, others).

The number 720 stands for the 720 horizontal scan lines of image display resolution (also known as 720 pixels of vertical resolution). The p stands for progressive scan, i.e. non-interlaced. When broadcast at 60.00 frames/s frames per second, 720p features the highest temporal resolution possible under the ATSC and DVB standards. The term assumes a widescreen aspect ratio of 16:9, thus implying a resolution of 1280×720 px (0.9 megapixels).

720i (720 lines interlaced) is an erroneous term found in numerous sources and publications. Typically, it is a typographical error in which the author is referring to the 720p HDTV format. However, in some cases it is incorrectly presented as an actual alternative format to 720p. No proposed or existing broadcast standard permits 720 interlaced lines in a video frame at any frame rate.


Canals, or navigations, are human-made channels, or artificial waterways, for water conveyance, or to service water transport vehicles.

In most cases, the engineered works will have a series of dams and locks that create reservoirs of low speed current flow. These reservoirs are referred to as slack water levels, often just called levels.

A canal is also known as a navigation when it parallels a river and shares part of its waters and drainage basin, and leverages its resources by building dams and locks to increase and lengthen its stretches of slack water levels while staying in its valley.

In contrast, a canal cuts across a drainage divide atop a ridge, generally requiring an external water source above the highest elevation.

Many canals have been built at elevations towering over valleys and other water ways crossing far below.

Canals with sources of water at a higher level can deliver water to a destination such as a city where water is needed. The Roman Empire's aqueducts were such water supply canals.

Digital subchannel

In broadcasting, digital subchannels are a method of transmitting more than one independent program stream simultaneously from the same digital radio or television station on the same radio frequency channel. This is done by using data compression techniques to reduce the size of each individual program stream, and multiplexing to combine them into a single signal. The practice is sometimes called "multicasting".


HDV is a format for recording of high-definition video on DV cassette tape. The format was originally developed by JVC and supported by Sony, Canon, and Sharp. The four companies formed the HDV consortium in September 2003.

Conceived as an affordable high definition format for digital camcorders, HDV quickly caught on with many amateur and professional videographers due to its low cost, portability, and image quality acceptable for many professional productions.

HDV and HDV logo are trademarks of JVC and Sony.

High-definition television

High-definition television (HDTV) is a television system providing an image resolution that is of substantially higher resolution than that of standard-definition television. This can be either analog or digital. HDTV is the current standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television, Blu-rays, and streaming video.

HDTV may be transmitted in various formats:

720p (HD ready): 1280×720p: 923,600 pixels (~0.92 MP) per frame

1080i (full HD) : 1920×1080i: 1,036,800 pixels (~1.04 MP) per field or 2,073,600 pixels (~2.07 MP) per frame

1080p (full HD): 1920×1080p: 2,073,600 pixels (~2.07 megapixels) per frame

Some countries also use a non-standard CEA resolution, such as 1440×1080i: 777,600 pixels (~0.78 MP) per field or 1,555,200 pixels (~1.56 MP) per frameThe letter "p" here stands for progressive scan, while "i" indicates interlaced.

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. HDTV as is known today first started official broadcasting in 1989 in Japan, under the MUSE/Hi-Vision analog system. HDTV was widely adopted worldwide in the late 2000s.

High-definition television in the United States

High-definition television (HDTV) in the United States was introduced in 1998 and has since become increasingly popular and dominant in the television market. Hundreds of HD channels are available in millions of homes and businesses both terrestrially and via subscription services such as satellite, cable and IPTV. HDTV has quickly become the standard, with about 85% of all TVs used being HD as of 2018. In the US, the 720p and 1080i formats are used for linear channels, while 1080p is available on a limited basis, mainly for pay-per-view and video on demand content.

Interlaced video

Interlaced video 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 at two different times. This enhances motion perception to the viewer, and reduces flicker by taking advantage of the phi phenomenon.

This effectively doubles the time resolution (also called temporal resolution) as compared to non-interlaced footage (for frame rates equal to field rates). Interlaced signals require a display that is natively capable of showing the individual fields in a sequential order. CRT displays and ALiS plasma displays are made for displaying interlaced signals.

Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the other being progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all odd-numbered lines in the image; the other contains all even-numbered lines.

A Phase Alternating Line (PAL)-based television set display, for example, scans 50 fields every second (25 odd and 25 even). The two sets of 25 fields work together to create a full frame every 1/25 of a second (or 25 frames per second), but with interlacing create a new half frame every 1/50 of a second (or 50 fields per second). To display interlaced video on progressive scan displays, playback applies deinterlacing to the video signal (which adds input lag).

The European Broadcasting Union has argued against interlaced video in production and broadcasting. They recommend 720p 50 fps (frames per second) for the current production format—and are working with the industry to introduce 1080p 50 as a future-proof production standard. 1080p 50 offers higher vertical resolution, better quality at lower bitrates, and easier conversion to other formats, such as 720p 50 and 1080i 50. The main argument is that no matter how complex the deinterlacing algorithm may be, the artifacts in the interlaced signal cannot be completely eliminated because some information is lost between frames.

Despite arguments against it, television standards organizations continue to support interlacing. It is still included in digital video transmission formats such as DV, DVB, and ATSC. New video compression standards like High Efficiency Video Coding are optimized for progressive scan video, but sometimes do support interlaced video.

List of DTT channels in the United Kingdom

This is a list of the current channels available on digital terrestrial television (DTT) in the United Kingdom, and those that have been removed.

Almost all channels broadcast on DTT are free-to-air, with a limited number of subscription channels (requiring a subscription to a pay-TV package) and pay-per-view channels (requiring a one-off payment to view an event) also available. Most free-to-air channels are promoted as part of the Freeview line-up.

All multiplexed H.222 transports for HDTV (1080i) channels use DVB-T2 256-QAM modulation. Local channels on the LTVmux use DVB-T QPSK modulation. All other transports for PAL (576i), radio and interactive channels use DVB-T 64-QAM modulation.

All HD channels are encoded in H.264 and subject to a MPEG-LA controlled transmission patent licensing tax which is included in the Freeview broadcaster cost and varies on viewership figures. This tax is currently paid via one of three registered licensees: the BBC, ITV and Sky plc. The SD channels continue to use H.262, which does not incur any additional transmission costs.

The PSB1 transport (operating name BBC A) is used solely for the standard definition PSB (public service broadcasting) services of the BBC. The PSB2 transport (operating name D3&4) carries only standard definition versions of both the commercial broadcasters' PSB services and some of their commercial services. The PSB3 transport (operating name BBC B) is used for HDTV versions of most of the BBC and commercial PSB services and for standard definition commercial services (viz Film4 +1). The COM4 (operating name SDN), COM5 (operating name ARQ A) and COM6 (operating name ARQ B) transports, which are only transmitted from main transmission sites, carry only standard definition commercial services. The even less geographically available COM7 and COM8 transports, only broadcast from a few principal transmitting sites at significantly lower power than the other transports, carry both commercial HDTV and commercial standard definition services; SDTV channels on these multiplexes can only be received by HDTV-capable equipment.

LTVmux is a series of localised transports at certain transmitter sites carrying local and nationwide channels. Its availability is much less than that of the commercial COM transports. In addition to this, the NImux transport (operating name RNI_1) is only available in parts of Northern Ireland, and the GImux transport (operating name G_MAN) is only available in Greater Manchester.

List of HD channels in the United Kingdom

This is a list of current high definition channels that are available in the United Kingdom, together with those coming in the future, and those that have ceased broadcasting.

All HD channels in the UK broadcast at 1080i, apart from BT Sport 4K UHD and Virgin TV Ultra HD which are broadcast at 4K. HD channels can dynamically switch between 1080i/25 and 1080p/25 when broadcast via Freeview HD

List of digital television channels in Australia

This is a list of the current channels available on digital terrestrial television in Australia.

The commercial channels available to viewers depend on location and station ownership. The process of aggregation during the late 80s to mid 90s saw regional stations take on affiliations with metropolitan channels for programming, a practice that has continued into digital television with affiliated stations carrying various multichannels from their metropolitan counterparts.

Metropolitan in this list therefore refers to the capitals of Melbourne, Sydney, Brisbane, Adelaide and Perth, where stations are owned and operated by the network rather than affiliates.

In areas not covered by terrestrial transmissions, the digital channels are provided by the free-to-view VAST satellite platform. The television channels on this platform are all encoded in H.264 and subject to a MPEG-LA controlled transmission patent licensing tax which is included in the VAST broadcaster cost and varies on viewership figures. The terrestrial transmissions still use H.262, which doesn't incur any additional transmission costs, but select channels are broadcast terrestrially in H.264.

List of free-to-air channels at 28°E

This is a list of all of the free-to-air channels that are currently available via satellite from SES Astra satellites (Astra 2E/2F/2G) located at 28.2 °E. These are the same group of satellites used for the Sky pay-TV platform and the Freesat free-to-air platform, therefore existing installations for these platforms would not require a realignment of the satellite dish or the purchase of any additional equipment.

MTV Live (TV network)

MTV Live (formerly Palladia) is an American pay television network that is owned by Viacom. The channel, which exclusively broadcasts in 1080i high definition, broadcasts music videos and music-related programming from Viacom-owned networks MTV, MTV Classic, VH1 and CMT, along with other concert and live music programming from outside producers.

Sony Alpha 58

The Sony α58, Sony Alpha 58 also known as Sony A58 (model name SLT-A58) is a mid-range single-lens reflex digital camera from Sony's Alpha SLT camera line, introduced in 2013.

Sports broadcasting contracts in Kosovo

This article refers to sports broadcasting contracts in Kosovo. For a list of broadcasting rights in other countries, see Sports television broadcast contracts.

Surya TV

Surya TV is a Malayalam-language television channel in India, established in 1998. It is the second privately owned television channel in Malayalam, which began to air after Asianet. The channel is part of Sun TV Network headquartered at Chennai, Tamil Nadu. It operates from two studios in Kerala: Thiruvananthapuram and Kochi. On 16 March 2017, Surya TV became the third channel in Malayalam Television to be broadcast in 1080i Full HD and 7.1 Dolby Digital sound quality.

TVN Fabuła

TVN Fabula is a Polish TV channel launched April 16, 2015.

The channel assigns series of TVN, movie trailers, foreign series and own productions. It also broadcasts programs on culture, showbiz and talk show with actors. The channel is broadcast in HDTV (1080i). The viewver has the option to watch movies with a Polish voice over or with original soundtrack and Polish subtitles.The station broadcasts daily binge-watching series, meaning several episodes of one series in a row.


TVP HD is a special High Definition version of the Polish public broadcasting channels (Telewizja Polska). A digital terrestrial multiplex carrying the channel was available in Warsaw, Poznań, Zielona Góra, Żagań, Kraków, Leżajsk and Krosno from the 6 to 25 August 2008.

It was launched on August 2008. Broadcast is 1080i video encoded with MPEG4/H.264.

It is encrypted on Satellite (Astra 1KR at 19.2° east), with 18 hours of daily HD content. During the Olympic Games, the signal replaced TVP Polonia, TVP Historia and TVP Kultura.

Television in China

The television industry in China includes high-tech program production, transmission and coverage. China Central Television is China's largest and most powerful national television station. By 1987, two-thirds of people in China had access to television, while today, over 3,000 channels are available in the country.

Chinese television drama has also proven to be a hot spot in today's popular culture (similar to K-dramas), with well received Chinese television dramas such as Princess Agents, Nirvana in Fire, The Journey of Flower, Eternal Love, The Princess Weiyoung, Just One Smile Is Very Alluring, The Legend of Mi Yue, Scarlet Heart, General and I and more garnering billions of views among China's most popular video websites, iQiyi, Youku, Tencent Video and Le Video. Some dramas have been so popular and widely acclaimed that they were remade into different languages, as well as spinning off with a sequel.

Chinese variety scene has also became widely successful with popular shows such as Happy Camp, Super Girl, Sing! China and more gaining worldwide recognition, garnering from millions to billions of viewership and winning numerous awards.

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