Active Format Description

In television technology, Active Format Description (AFD) is a standard set of codes that can be sent in the MPEG video stream or in the baseband SDI video signal that carries information about their aspect ratio and active picture characteristics. It has been used by television broadcasters to enable both 4:3 and 16:9 television sets to optimally present pictures transmitted in either format. It has also been used by broadcasters to dynamically control how down-conversion equipment formats widescreen 16:9 pictures for 4:3 displays.

Standard AFD codes provide information to video devices about where in the coded picture the active video is and also the "protected area" which is the area that needs to be shown. Outside the protected area, edges at the sides or the top can be removed without the viewer missing anything significant. Video decoders and display devices can then use this information, together with knowledge of the display shape and user preferences, to choose a presentation mode.

AFD can be used in the generation of Widescreen signaling, although MPEG alone contains enough information to generate this. AFDs are not part of the core MPEG standard; they were originally developed within the Digital TV Group in the UK and submitted to DVB as an extension, which has subsequently also been adopted by ATSC (with some changes). SMPTE has also adopted AFD for baseband SDI carriage as standard SMPTE 2016-1-2007, "Format for Active Format Description and Bar Data".

Active Format Description is occasionally incorrectly referred to as "Active Format Descriptor". There is no "descriptor" (descriptor has a specific meaning in ISO/IEC 13818-1, MPEG syntax). The AFD data is carried in the Video Layer of MPEG, ISO/IEC 13818-2. When carried in digital video, AFDs can be stored in the Video Index Information, in line 11 of the video.

By using AFDs broadcasters can also control the timing of Aspect Ratio switches more accurately than using MPEG signalling alone. This is because the MPEG signalling can only change with a new Group of Pictures in the sequence, which is typically around every 12 frames or half a second - this was not considered accurate enough for some broadcasters who were initially switching frequently between 4:3 and 16:9. The number of Aspect Ratio Converters required in a broadcast facility is also reduced, since the content is described correctly it does not need to be resized for broadcast on a platform that supports AFDs.

In 2012, a Technology & Engineering Emmy Award was awarded for the development and deployment of Active Format Description.[1]

Usage

A widescreen 16:9 signal may be broadcast with AFD 8 or AFD 10, indicating that the entire frame includes important picture information and should not be cropped. On a 4:3 TV, this will then be shown as a 16:9 letterbox to ensure no image is lost. Other widescreen 16:9 content (like sports coverage) may be broadcast with AFD 15, indicating that it is safe to display only the central 4:3 region. On a 4:3 TV, the image will be cropped and it will be shown full-screen.

As of 2006, AFDs are only broadcast in a minority of the countries using MPEG digital television but used most notably in the UK as required by the Digital TV Group D-Book.[2] As a result, the quality of implementation in receivers is variable. Some receivers only respect the basic "active area" information. More fully featured receivers also support the "safe area" information, and will use this to optimise the display for the shape of the viewer's screen. Display in the compromise 14:9 letterbox format was not supported by initial British receivers, which limited the value of the AFD flags - this ratio is especially useful when watching widescreen material on smaller 4:3 sets.

AFD for the DVB DTV transition

The line 23 data format allows signaling of the source (coded image) aspect ratio and the Active Format Descriptor.[3]

Bits Format
000 Active region same as coded frame (source material)
001 4:3
010 16:9
011 14:9
100 not used - reserved for future use
101 4:3 with shoot and protect 14:9 center
110 16 : 9 with shoot and protect 14:9 center
111 not used - reserved for future use

AFD for the ATSC DTV transition

A concerted effort on the part of US broadcasters to broadcast AFD began in 2008 in preparation for the US DTV transition which occurred on June 12, 2009.

After the DTV transition, 4:3 versions of programming are not available directly from a large percentage of US broadcasters. Cable and satellite providers down-convert 16:9 HD feeds from these broadcasters to generate the 4:3 SD versions for their SD viewers. The most common forms of down-conversion are letterbox or center-cut (cropping off the left and right sides of the 16:9 image to fit into the 4:3 raster).

Some US broadcasters transmit AFD with their HD DTV signals in order to maintain control over how SD viewers will receive their programming. With AFD included in these signals, cable and satellite providers are able to dynamically control whether HD content is to be either letterbox or center-cut for their SD viewers. However, there are cases where pay-TV providers completely disregard AFD instructions and for instance, present a 4:3 picture with widescreen elements cut off to assuage user complaints about letterboxing, on standard 4:3 sets (for instance for a secondary-market station available only in standard definition on a provider on the claim that an HD signal exists for the provider's 'primary' station for a network), to the displeasure of broadcasters.

Without AFD, either a fixed letterbox or center-cut will be required on a station-by-station basis. A fixed letterbox will result in an undesirable windowbox (i.e., a combination of letterbox and pillarbox, also called "postage stamp") effect on SD originated programming. A fixed center-cut will result in loss of important picture content on certain HD content (e.g., an HD sports broadcast containing score graphics formatted for 16:9 display).

Complete list of AFD codes

Values from ETSI TS 101 154 V1.7.1 Annex B, ATSC A/53 Part 4 and SMPTE 2016-1-2007

0 0000 ETSI: reserved; ATSC: undefined
1 0001 reserved
2 0010 ETSI: 16:9 active picture (top aligned); ATSC: "not recommended"
3 0011 ETSI: 14:9 active picture (top aligned); ATSC: "not recommended"
4 0100 ETSI: box > 16:9 (center): wider than 16:9 active picture. The aspect ratio of the source area is not given, and the size of the top/bottom bars is not indicated.
ATSC: bar data (indicating the extent of top, bottom, left, and right bars) should be transmitted when using this code.
5–7 reserved
8 1000 Full Frame image, same as the frame (4:3 or 16:9).
9 1001 4:3 Image: Full Frame in 4:3 frame, Pillarbox in 16:9 frame.
10 1010 16:9 Image: Letterbox in 4:3 frame, Full Frame in 16:9 frame.
11 1011 14:9 Pillarbox/Letterbox image.
12 1100 reserved
13 1101 4:3 with shoot and protect 14:9 centre. The term "shoot and protect" is not explained in the standard, but means that the areas above and below the central 14:9 region of the 4:3 active picture can be trimmed without losing important detail.
14 1110 16:9 with shoot and protect 14:9 centre. Here, the areas to the right and left of the central 14:9 region of the 16:9 active picture can be trimmed without losing important detail.
15 1111 16:9 with shoot and protect 4:3 centre. Here, the areas to the right and left of the central 4:3 region of the 16:9 active picture can be trimmed without losing important detail.

Chart illustrating above codes

Illustration of above codes, in 4:3, 16:9 and 21:9 frames. Green circles represent essential content, orange circles indicate optional image areas. Black areas are unused parts of the frame, i.e. bars. The red edge indicates the full frame.

Illustration of above codes, in 4:3, 16:9 and 21:9 frames. Green circles represent essential content, orange circles indicate optional image areas. Black areas are unused parts of the frame, i.e. bars. The red edge indicates the full frame.

(Left column showing content in a 4:3 frame, center column in a 16:9 frame, right column in a 21:9 frame)

See also

References

  1. ^ Group, Andy Finney ATSF for the Digital TV. "DTG :: News :: DTG collects Emmy Award". www.dtg.org.uk.
  2. ^ Group, Andy Finney ATSF for the Digital TV. "DTG Publications: D-Book". www.dtg.org.uk.
  3. ^ http://www.divitec.se/sites/default/files/microvideo_wss-dec.pdf

External links

ATSC-M/H

ATSC-M/H (Advanced Television Systems Committee - Mobile/Handheld) is a U.S. standard for mobile digital TV that allows TV broadcasts to be received by mobile devices.ATSC-M/H is a mobile TV extension to preexisting terrestrial TV broadcasting standard ATSC A/53. It corresponds to the European DVB-H and 1seg extensions of DVB-T and ISDB-T terrestrial digital TV standards respectively. ATSC is optimized for a fixed reception in the typical North American environment and uses 8VSB modulation. The ATSC transmission method is not robust enough against Doppler shift and multipath radio interference in mobile environments, and is designed for highly directional fixed antennas. To overcome these issues, additional channel coding mechanisms are introduced in ATSC-M/H to protect the signal.

Anamorphic widescreen

Anamorphic widescreen (also called Full height anamorphic) is a process by which a comparatively wide widescreen image is horizontally compressed to fit into a storage medium (photographic film or MPEG-2 Standard Definition frame, for example) with a narrower aspect ratio, reducing the horizontal resolution of the image while keeping its full original vertical resolution. Compatible play-back equipment (a projector with modified lens, or a digital video player or set-top box) can then expand the horizontal dimension to show the original widescreen image. This is typically used to allow one to store widescreen images on a medium that was originally intended for a narrower ratio, while using as much of the frame – and therefore recording as much detail – as possible.The technique comes from cinema, when a film would be framed and recorded as widescreen but the picture would be "squashed together" using a special concave lens to fit into non-widescreen 1.37:1 aspect ratio film. This film can then be printed and manipulated like any other 1.37:1 film stock, although the images on it will appear to be squashed horizontally (or elongated vertically). An anamorphic lens on the projector in the cinema (a convex lens) corrects the picture by performing the opposite distortion, returning it to its original width and its widescreen aspect ratio.

The anamorphic lens on the projector is a special convex lens that corrects the picture so that the images on the screen look normal. The optical scaling of the lens to a film medium is considered more desirable than the digital counterpart, due to the amount of non-proportional pixel-decimated scaling that is applied to the width of an image to achieve (something of a misnomer) a so-called "rectangular" pixel widescreen image. The legacy ITU Rec. 601 4:3 image size is used for its compatibility with the original video bandwidth that was available for professional video devices that used fixed clock rates of a SMPTE 259M serial digital interface. One would produce a higher-quality upscaled 16:9 widescreen image by using either a 1:1 SD progressive frame size of 640×360 or for ITU Rec. 601 and SMPTE 259M compatibility a letterboxed frame size of 480i or 576i. Similar operations are performed electronically to allow widescreen material to be stored on formats or broadcast on systems that assume a non-widescreen aspect ratio, such as DVD or standard definition digital television broadcasting.

Aspect ratio (image)

The aspect ratio of an image describes the proportional relationship between its width and its height. It is commonly expressed as two numbers separated by a colon, as in 16:9. For an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this same length unit, the height will be measured to be y units.

For example, in a group of images that all have an aspect ratio of 16:9, one image might be 16 inches wide and 9 inches high, another 16 centimeters wide and 9 centimeters high, and a third might be 8 yards wide and 4.5 yards high. Thus, aspect ratio concerns the relationship of the width to the height, not an image's actual size.

CBS Sports

CBS Sports is the sports division of the American television network CBS. Its headquarters are in the CBS Building on West 52nd Street in midtown Manhattan, New York City, with programs produced out of Studio 43 at the CBS Broadcast Center on West 57th Street.

Its premier sports properties are the NFL, Southeastern Conference (SEC) football, NCAA basketball (including telecasts of the NCAA Men's Basketball Tournament), and PGA golf, including The Masters, and the PGA Championship.

The online arm of CBS Sports is CBSSports.com. CBS purchased SportsLine.com in 2004, and today CBSSports.com is part of CBS Interactive. On February 26, 2018, following up on the success of their online news network CBSN, CBS Sports launched CBS Sports HQ, a 24/7, online only, linear sports news network. The network focuses entirely on sports news, results, highlights and analysis. (CBS Sports college sports and golf programming that it distributes over the air is generally made available for free via separate streams, as are a limited number of NFL national telecasts; the remainder requires a CBS All Access subscription to be viewed online, with CBS Sports Network programming requiring a TV Everywhere subscription.)

CBS Sports was honored at the 59th Annual Technology & Engineering Emmy Awards for Outstanding Achievement in Advanced Media Technology for Synchronous Enhancement of Original Television Content for Interactive Use for its program March Madness on Demand.

On August 31, 2013, CBS Sports rolled out its previous graphics and animation package that was first used in the network's coverage of Super Bowl XLVII. Additionally, in compliance with the Active Format Description #10 code, CBS Sports switched to a 16:9 aspect ratio letterbox presentation used for all sports programming, including the SEC on CBS and the NFL on CBS broadcasts.

On November 30, 2015, CBS Sports released a new logo in order to coincide with the network's coverage of Super Bowl 50. The network also created a new on-air graphics package that debuted as part of the network's Super Bowl week programming. Following the game, the graphics package began to be utilized across all of their programming events, including their joint production of NCAA March Madness with Turner Sports. The Masters, which retains heavy production control over their event, will continue to use the network's older graphical style originally unveiled in 2007. Also, the network's Thursday Night Football game broadcasts continued to use the graphical style originally used since its debut in 2014 until its rights to that package expired in 2018.

Ericsson Television

Ericsson Television, formerly Tandberg Television, is a company providing MPEG-4 AVC, MPEG-2 and HEVC encoding decoding and control solutions, plus stream processing, packaging, network adaption and related products, for Contribution & Distribution (C+D), IPTV, Cable, DTT, Satellite DTH and OTT.

The global headquarters are located in Southampton, England with additional offices in Rennes, France.

The company was honored with its first Technology & Engineering Emmy Award in 2008 for the development of interactive Video-on-Demand infrastructure and signaling, leading to large scale VOD implementations.

It was also awarded another Emmy® in 2009 for Pioneering Development of MPEG-4 AVC systems for HDTV. Then in 2011, for the Pioneering Development and Deployment of Active Format Description Technology and System. In 2013, the company acquired another Emmy® award for the Pioneering Development Of Video On Demand (VOD) Dynamic Advertising Insertion. Recently in 2014, Ericsson got its fifth Emmy® Award recognition for its work in developing pioneering JPEG2000 interoperability technology.

Letterboxing (filming)

Letterboxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting videographic image has mattes (black bars) above and below it; these mattes are part of the image (i.e., of each frame of the video signal). LBX or LTBX are the identifying abbreviations for films and images so formatted. The term refers to the shape of a letter box, a slot in a wall or door through which mail is delivered, being rectangular and wider than it is high.

Mid-Atlantic Sports Network

Mid-Atlantic Sports Network (MASN) is an American regional sports network owned as a joint venture between two Major League Baseball franchises, the Baltimore Orioles (which owns a controlling 90% interest) and the Washington Nationals (which owns the remaining 10%). Headquartered in Baltimore, Maryland, the channel broadcasts regional coverage of sports events in the Baltimore–Washington metropolitan area.

MASN is available on approximately 23 cable and fiber optic television providers in Maryland, the District of Columbia, Virginia, eastern and central North Carolina, West Virginia, south central Pennsylvania and Delaware (on providers such as Comcast, Cox Communications, RCN, Mediacom, Charter Communications and Verizon FiOS, covering an area stretching from Harrisburg, Pennsylvania to Charlotte, North Carolina); it is also available nationwide on satellite via DirecTV and Dish Network.

Technology

Technology ("science of craft", from Greek τέχνη, techne, "art, skill, cunning of hand"; and -λογία, -logia) is the collection of techniques, skills, methods, and processes used in the production of goods or services or in the accomplishment of objectives, such as scientific investigation. Technology can be the knowledge of techniques, processes, and the like, or it can be embedded in machines to allow for operation without detailed knowledge of their workings. Systems (e. g. machines) applying technology by taking an input, changing it according to the system's use, and then producing an outcome are referred to as technology systems or technological systems.

The simplest form of technology is the development and use of basic tools. The prehistoric discovery of how to control fire and the later Neolithic Revolution increased the available sources of food, and the invention of the wheel helped humans to travel in and control their environment. Developments in historic times, including the printing press, the telephone, and the Internet, have lessened physical barriers to communication and allowed humans to interact freely on a global scale.

Technology has many effects. It has helped develop more advanced economies (including today's global economy) and has allowed the rise of a leisure class. Many technological processes produce unwanted by-products known as pollution and deplete natural resources to the detriment of Earth's environment. Innovations have always influenced the values of a society and raised new questions of the ethics of technology. Examples include the rise of the notion of efficiency in terms of human productivity, and the challenges of bioethics.

Philosophical debates have arisen over the use of technology, with disagreements over whether technology improves the human condition or worsens it. Neo-Luddism, anarcho-primitivism, and similar reactionary movements criticize the pervasiveness of technology, arguing that it harms the environment and alienates people; proponents of ideologies such as transhumanism and techno-progressivism view continued technological progress as beneficial to society and the human condition.

Video scaler

A video scaler is a system which converts video signals from one display resolution to another; typically, scalers are used to convert a signal from a lower resolution (such as 480p standard definition) to a higher resolution (such as 1080i high definition), a process known as "upconversion" or "upscaling" (by contrast, converting from high to low resolution is known as "downconversion" or "downscaling").

Video scalers are typically found inside consumer electronics devices such as televisions, video game consoles, and DVD or Blu-ray disc players, but can also be found in other AV equipment (such as video editing and television broadcasting equipment). Video scalers can also be a completely separate devices, often providing simple video switching capabilities. These units are commonly found as part of home theatre or projected presentation systems. They are often combined with other video processing devices or algorithms to create a video processor that improves the apparent definition of video signals.

Video scalers are primarily a digital device; however, they can be combined with an analog-to-digital converter (ADC, or digitizer) and a digital-to-analog converter (DAC) to support analog inputs and outputs.

Widescreen

Widescreen images are images that are displayed within a set of aspect ratios (relationship of image width to height) used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film.

For television, the original screen ratio for broadcasts was in fullscreen 4:3 (1.33:1). Largely between the 1990s and early 2000s, at varying paces in different nations, 16:9 (1.78:1) widescreen TV displays came into increasingly common use. They are typically used in conjunction with high-definition television (HDTV) receivers, or Standard-Definition (SD) DVD players and other digital television sources.

With computer displays, aspect ratios wider than 4:3 are also referred to as widescreen. Widescreen computer displays were previously of 16:10 aspect ratio, but now are usually 16:9.

Widescreen signaling

In television technology, widescreen signaling (WSS) is a digital stream embedded in the analog TV signal describing qualities of the broadcast, in particular the intended aspect ratio of the image. This can be used by a widescreen TV or other device to switch to the correct display mode.

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