720p

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This chart shows the most common display resolutions, 720p being one of the 16:9 formats shown in blue. Vector Video Standards8.svg
This chart shows the most common display resolutions, 720p being one of the 16:9 formats shown in blue.

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).

Contents

The number 720 stands for the 720 horizontal scan lines of image display resolution (also known as 720 pixels of vertical resolution). [1] The p stands for progressive scan, i.e. non-interlaced. When broadcast at 60 [note 1] 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. [3] No proposed or existing broadcast standard permits 720 interlaced lines in a video frame at any frame rate. [4]

Comparison with 1080p

Progressive scanning reduces the need to prevent flicker by anti-aliasing single high contrast horizontal lines. [5] [6] It is also easier to perform high-quality 50↔60 Hz conversion and slow-motion clips with progressive video.

A 720p60 (720p at 59.94 Hz) video has advantage over 480i and 1080i60 (29.97/30 frame/s, 59.94/60 Hz) in that it comparably reduces the number of 3:2 artifacts introduced during transfer from 24 frame/s film. However, 576i and 1080i50 (25 frame/s, 50 Hz), which are common in Europe, generally do not suffer from pull down artifacts as film frames are simply played at 25 frames and the audio pitch corrected by 25/24. As a result, 720p60 is used for U.S. broadcasts while European HD broadcasts often use 1080i50 24* frame, with a horizontal resolution of 1920 or 1440 depending on bandwidth constraints. However, some European broadcasters do use the 720p50 format, such as German broadcasters ARD and ZDF, and the Norwegian Broadcasting Corporation (NRK). Arte, a dual-language French-German channel produced in collaboration by ARD, ZDF and France Télévisions, broadcasts in German at 720p50 but in French at 1080i50. The Flemish Broadcasting Company (VRT) in Belgium was using 720p50, but switched to 1080i50 a few years ago.[ when? ]

Resolutions

StandardResolutionAspect ratio
vintage Small TVs960×7204:3
Standard1280x72016:9

Notes

  1. It is, however, more commonly broadcast at (60/1.001), or precisely 59.940059, matching the NTSC SDTV field rate; this and the 50.00 Hz of PAL are still the second and third highest standard framerates. [2]

See also

Related Research Articles

MPEG-2 Video encoding standard

MPEG-2 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, which permit storage and transmission of movies using currently available storage media and transmission bandwidth. While MPEG-2 is not as efficient as newer standards such as H.264/AVC and H.265/HEVC, backwards compatibility with existing hardware and software means it is still widely used, for example in over-the-air digital television broadcasting and in the DVD-Video standard.

NTSC Analog color television system developed in the United States

The abbreviation NTSC can refer to the National Television System Committee, which developed the analog television color system that was introduced in North America in 1954 and stayed in use until digital conversion. NTSC is also an abbreviation for the National Television Standards Committee, a subset of the National Television System Committee that was responsible for producing the detailed technical specifications for the transmission standard. It is one of three major analog color television standards, the others being PAL and SECAM.

Standard-definition television Original analog television systems

Standard-definition television is a television system which uses a resolution that is not considered to be either high or enhanced definition. SDTV and high-definition television (HDTV) are the two categories of display formats for digital television (DTV) transmissions. "Standard" refers to the fact that it was the prevailing specification for broadcast television in the mid- to late-20th century.

Interlaced video Technique for doubling the perceived frame rate of a video display

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 consecutively. This enhances motion perception to the viewer, and reduces flicker by taking advantage of the phi phenomenon.

Telecine Process for broadcasting content stored on film stock

Telecine is the process of transferring motion picture film into video and is performed in a color suite. The term is also used to refer to the equipment used in the post-production process. Telecine enables a motion picture, captured originally on film stock, to be viewed with standard video equipment, such as television sets, video cassette recorders (VCR), DVD, Blu-ray Disc or computers. Initially, this allowed television broadcasters to produce programmes using film, usually 16mm stock, but transmit them in the same format, and quality, as other forms of television production. Furthermore, telecine allows film producers, television producers and film distributors working in the film industry to release their products on video and allows producers to use video production equipment to complete their filmmaking projects. Within the film industry, it is also referred to as a TK, because TC is already used to designate timecode. Motion picture film scanners are similar to telecines.

Advanced Television Systems Committee (ATSC) standards are an American set of standards for digital television transmission over terrestrial, cable and satellite networks. It is largely a replacement for the analog NTSC standard and, like that standard, is used mostly in the United States, Mexico, Canada, and South Korea. Several former NTSC users, in particular Japan, have not used ATSC during their digital television transition, because they adopted their own system called ISDB.

Broadcast television systems are the encoding or formatting standards for the transmission and reception of terrestrial television signals. There were three main analog television systems in use around the world until the late 2010s: NTSC, PAL, and SECAM. Now in digital terrestrial television (DTT), there are four main systems in use around the world: ATSC, DVB, ISDB and DTMB.

Enhanced-definition television, or extended-definition television (EDTV) is a Consumer Electronics Association (CEA) marketing shorthand term for certain digital television (DTV) formats and devices. Specifically, this term defines formats that deliver a picture superior to that of standard-definition television (SDTV) but not as detailed as high-definition television (HDTV).

Display resolution Number of distinct pixels in each dimension that can be displayed

The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode ray tube (CRT) displays, flat-panel displays and projection displays using fixed picture-element (pixel) arrays.

HD-MAC was a proposed broadcast television systems standard by the European Commission in 1986, a part of Eureka 95 project. It is an early attempt by the EEC to provide High-definition television (HDTV) in Europe. It is a complex mix of analogue signal, multiplexed with digital sound, and assistance data for decoding (DATV). The video signal was encoded with a modified D2-MAC encoder.

480p is the shorthand name for a family of video display resolutions. The p stands for pixels scan, i.e. non-interlaced. The 480 denotes a vertical resolution of 480 pixels, usually with a horizontal resolution of 640 pixels and 4:3 aspect ratio or a horizontal resolution of 854 or less pixels for an approximate 16:9 aspect ratio. Since a pixel count must be a whole number, in Wide VGA displays it is generally rounded up to 854 to ensure inclusion of the entire image. The frames are displayed progressively as opposed to interlaced. 480p was used for many early plasma televisions. Standard definition has always been a 4:3 aspect ratio with a pixel resolution of 640 × 480 at 60Hz for NTSC regions, and 720 or 768 × 576 for PAL regions (1024 wide for widescreen displays. However, standard definition defines a 15.7Khz horizontal scanrate, which means that interlacing has to be used for those resolution modes. The lowercase letter "p" in 480p stands for progressive, so the two must not be confused.

1080i is a combination of frame resolution and scan type. 1080i is 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 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" on the screen in sequence.

480i Standard-definition video mode

480i is the video mode used for standard-definition analog or digital television in the Caribbean, Myanmar, Japan, South Korea, Taiwan, Philippines, Laos, Western Sahara, and most of the Americas. The 480 identifies a vertical resolution of 480 lines, and the i identifies it as an interlaced resolution. The field rate, which is 60 Hz, is sometimes included when identifying the video mode, i.e. 480i60; another notation, endorsed by both the International Telecommunication Union in BT.601 and SMPTE in SMPTE 259M, includes the frame rate, as in 480i/30. The other common standard, used in the other parts of the world, is 576i.

576i Standard-definition video mode

576i is a standard-definition video mode originally used for terrestrial television in most countries of the world where the utility frequency for electric power distribution is 50 Hz. Because of its close association with the colour encoding system, it is often referred to as simply PAL, PAL/SECAM or SECAM when compared to its 60 Hz NTSC-colour-encoded counterpart, 480i. In digital applications it is usually referred to as "576i"; in analogue contexts it is often called "625 lines", and the aspect ratio is usually 4:3 in analogue transmission and 16:9 in digital transmission.

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 768 or 1024, depending of the relationship aspect. The 576p quality was decided as the default quality when converting from VHS to digital. 576p is considered standard definition for PAL video. The frame rate can be given explicitly after the letter.

High-definition video is video of higher resolution and quality than standard-definition. While there is no standardized meaning for high-definition, generally any video image with considerably more than 480 vertical scan lines or 576 vertical lines (Europe) is considered high-definition. 480 scan lines is generally the minimum even though the majority of systems greatly exceed that. Images of standard resolution captured at rates faster than normal, by a high-speed camera may be considered high-definition in some contexts. Some television series shot on high-definition video are made to look as if they have been shot on film, a technique which is often known as filmizing.

1080p Video mode

1080p 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 screen vertically; the p stands for progressive scan, i.e. non-interlaced. The term usually assumes a widescreen aspect ratio of 16:9, implying a resolution of 2.1 megapixels. It is often marketed as Full HD or FHD, to contrast 1080p with 720p resolution screens. Although 1080p is sometimes informally referred to as 2K, these terms reflect two distinct technical standards, with differences including resolution and aspect ratio.

Low-definition television (LDTV) refers to TV systems that have a lower screen resolution than standard-definition TV systems. The term is usually used in reference to digital TV, in particular when broadcasting at the same resolution as low-definition analog TV systems. Mobile DTV systems usually transmit in low definition, as do all slow-scan TV systems.

High-definition television (HD) describes a television system providing an image resolution of substantially higher resolution than the previous generation of technologies. The term has been used since 1936, but in modern times refers to the generation following standard-definition television (SDTV), often abbreviated to HDTV or HD-TV. It is the current de facto standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television and Blu-ray Discs.

References

  1. "720p – AfterDawn: Glossary of technology terms & acronyms".
  2. Hoffner, Randy (2008-01-09). "Will the End of NTSC Be the End of 59.94?". TVTechnology. Retrieved 2010-10-08.
  3. Briere, Daniel; Patrick Hurley (2006). HDTV for Dummies. For Dummies. p. 13. ISBN   9780470096734.
  4. "ATSC Standard: Video System Characteristics of AVC in the ATSC Digital Television System" (PDF). 2008-07-29. Archived from the original (PDF) on 2012-10-04. Retrieved 2011-07-24.
  5. "720p". AfterDawn. 2010-08-10. Retrieved 2010-10-08.
  6. "720p". CNET Glossary. Archived from the original on 2010-09-30. Retrieved 2010-10-08.