PALplus

Last updated

PALplus [1] (or PAL+) is an analogue television broadcasting system aimed to improve and enhance the PAL format by allowing 16:9 (or 1.77:1) aspect ratio broadcasts, while remaining compatible with existing television receivers, [2] defined by International Telecommunication Union (ITU) recommendation BT.1197-1. [1] Introduced in 1993, [3] it followed experiences with the HD-MAC (high definition) and D2-MAC, hybrid analogue-digital widescreen formats that were incompatible with PAL receivers. It was developed at the University of Dortmund in Germany, in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. The system had some adoption across Europe during the late 1990s and helped introduce widescreen TVs in the market, but never became mainstream.[ citation needed ]

Contents

A similar system, developed in Japan at the same time and named EDTV-II/ Wide-aspect Clear-vision, allows for 16:9 NTSC broadcasts. [4] [5] [6] [7] [8]

History

The MAC family of standards was adopted in Europe in 1983, [9] primarily for Direct Broadcasting by Satellite (DBS) services. This was an evolution from older color TV systems (such as PAL or SECAM) fixing the problems of interference between luminance and chrominance, and providing a stepping stone for a future HDTV system. [10] [9] In 1986, a new high definition broadcasting standard, HD-MAC, was presented, offering twice the number of scanning lines compared to PAL. [11] A transitional standard, D2-MAC was established. [12] It had the same number of lines as PAL, but like HD-MAC it was designed for 16:9 widescreen content.

In 1989, the PALplus strategy group was founded. The goal was to develop an enhanced system for terrestrial transmission compatible with PAL. European terrestrial broadcasters felt the need to better position themselves in order to compete with satellite and cable operators, in view of the introduction of MAC widescreen broadcasts. While not attempting to produce HDTV standards of quality, the new format was meant to improve PAL in the following areas:

In the beginning, the task group consisted of the public broadcasting corporations of Germany (ARD and ZDF), Austria (ORF), Switzerland (SRG) and the United Kingdom (BBC and UKIB, United Kingdom Independent Broadcasters) together with the consumer electronics manufacturers Grundig, Nokia, Philips and Thomson. [14] Sony as well as the Spanish (RTVE) and Portuguese (RTP) broadcasters joined the group later on.

At the Berlin IFA 1991, a first PALplus test transmission was demonstrated [15] [16]

At the Berlin IFA 1993, the first experimental PALplus broadcasts began. [17] In the same year, the European Union approved a plan to support the production and broadcast of 16:9 programs. [3] [18]

In 1994, broadcasters began adopting the format. In the United Kingdom, Channel 4 starts to broadcast using the system in October. [19] [20] Nokia launched the first PALplus TV set in Germany.

In 1995, the International Telecommunication Union publishes recommendation BT.1197-1, defining the PALplus system. [1] Originally, the PALplus consortium included the following manufacturers: Philips, Grundig, Thomson, Nokia and Sony. One of the four big Korean electronics manufacturers, Samsung, joined the PALplus consortium that year. [21] VCR manufacturers associated with the PALplus consortium were expected to launch updated VHS and S-VHS home recorders soon. The cost increment compared to conventional PAL VCRs was expected to be small. [21] PALplus was one of the highlights of the Berlin IFA 1995 edition. [22]

In January 1996, the PALplus board published the specifications of the standard in order to support the further dissemination of this standard for wide-screen transmissions. After German broadcasters started to broadcast some of their programmes using the format, the board ended its work by the end of that same year.[ original research? ]

At the beginning of 1998, PALplus programmes were broadcast on a regular basis in nine European countries, which made PALplus the mostly used standard for widescreen transmissions in Europe at that time. Evaluations, performed by ITU and EBU engineers in 1995-1998 concluded that the use of down-converted HDTV source material, as well as high-quality widescreen standard definition content, could be a significant benefit to the PALplus picture quality. Moreover, the experts felt that PALplus would not be out of place in an HDTV environment at viewing distances equal or farther to four heights of a television set. It was presumed that the standard method of display of a PALplus signal would be in 625-line interlaced (50 Hz) form, although other display formats (for example, 50 Hz progressive, 100 Hz interlace, or 100 Hz progressive) could be receiver options.[ citation needed ]

Countries and territories that used PALplus

The following countries and territories used the PALplus system:

Belgium

In Belgium, the Flemish public broadcasting service VRT had a policy that all of its self-created TV programmes are broadcast in PALplus. [23] The commercial TV station VTM used to broadcast a lot in PALplus. Even the third broadcasting organisation SBS Belgium with its stations VT4 and VijfTV used to broadcast in PALplus for all of their new productions.

The Walloon public broadcasting service RTBF used to broadcast 16:9 programmes that it purchased in PALplus, but preferred creating their own programmes in 4:3. Walloon commercial TV station RTL-TVI used to broadcast almost all its shows in PALPlus. [24]

In 2010, Belgium switched off analog television broadcast. [25]

Finland

In Finland, the commercial broadcaster MTV3 started broadcasting the youth music program Jyrki in PALplus format on August 18, 1997. [26] [27] The experiment ended when the program ended some four years later.

In 2007, Finland switched off analog television broadcast. [28]

Germany

In Germany, all public broadcasters (ARD, [29] [30] ZDF, etc.) complied with this standard. However, private broadcasters (RTL, ProSieben, etc) have shown no interest in either this standard or in the 16:9 format.[ dubious – discuss ][ citation needed ] Pay-per-view channels such as those on Sky often broadcast in 16:9, but use a different standard that requires another kind of decoder.

In 2008, Germany began switching off analog television broadcast. [28]

Greece

In Greece, there were sporadic PALplus broadcasts on the national television (E.R.T. - Hellenic Radio Television). Throughout the '90s several attempts from commercial broadcasters in adopting the system failed due to lack of popularity.

As some of the repeaters of ERT's channels were fed via OTE (Greek public telecom provider) in uncompressed form over terrestrial links, and others via NOVA (Greece's only satellite platform) using MPEG encoding, Palplus wasn't available on all areas. The heavy MPEG encoding on NOVA degraded WSS signaling and the additional information embedded in PALplus, making it undecodable.

Italy

It was used by broadcasters such as RAI (Italy). [31]

Ireland

RTÉ Ireland’s public service broadcaster, began to broadcast widescreen programming in 1995, initially on Network 2 Television in a special slot, mostly focused on documentaries, music and feature films, but over time more widescreen programming was introduced. [32]

Netherlands

In the Netherlands, the public broadcasters used PALplus up to 2005. [33] [34] With the switch to digital television and anamorphic widescreen, the system was discontinued with the end of terrestrial analogue broadcasts in November 2006. Analog broadcasts continued on cable operations, but PALplus wasn't used for down conversion on those services.

Poland

In Poland, the only documented use of PALplus is by TV Polonia on December 31, 1996. [35] [36]

Portugal

In Portugal, the private broadcaster TVI began broadcasting movies in PALplus in 1994, [37] but some years after it left the standard behind.

The public broadcaster RTP started using the format on December 5, 1997. [38] The system was used to broadcast selected programs (about five programs each day) and some widescreen movies on analog terrestrial broadcasts. Cable distributors occasionally strip the signal of the WSS bits, rendering the system inoperative. Also, when Digital Terrestrial Television broadcasts started, there was no dedicated anamorphic simulcast for the digital channels. Therefore, PALPlus over terrestrial analog PAL broadcasts remained the only source of 576 lines widescreen TV in Portugal for many years.

Since the middle of 2010 PALplus was dropped in favor of regular 16:9 letterbox, because the system caused considerable image degradation (with an effective horizontal resolution of only about ~400px compared to 720px of a digital SDTV image) when used on digital transmissions without any decoding.

With the end of analog broadcasts by 2012, the system became officially obsolete.

Spain

In Spain, the system was used by the public broadcaster RTVE. [39] The Catalan public television, TV3, trialed the PALplus format in 1994, with a weekly broadcast of a film in this format. [40] Other public regional stations (like Galicia's CRTVG) tested the format too, but after these trials the technology was dropped and 16:9 digital broadcasts were not introduced until 2007.

United Kingdom

In the United Kingdom, Channel 4 adopted the system to broadcast selected films after October 1994. [19] [20] Some programmes, including Fifteen to One and the omnibus edition of Brookside were also broadcast this way. BBC didn't adopt the system, opting instead for digital widescreen broadcasts. [19] All of the six main broadcasters, BBC, ITV, Channel 4, Five, Sky and Virgin Media, now broadcast in digital.

Analog television broadcast was switched off in the United Kingdom in 2012. [41]

Operation

A standard PAL receiver will display the 16:9 image in letterbox format with 432 active lines. This reproduces noticeably less detail than the 576 lines used for 4:3 broadcasts. A PALplus receiver can use extra information hidden in the black bars above and below the image to fully recover the 576 lines of vertical resolution. [2]

For compatibility reasons, the horizontal bandwidth remains at 5.0  MHz. This means that a PALplus signal provides no extra horizontal resolution to compensate for the image being stretched across a wider screen. The result is a horizontal resolution that is 73% of the vertical resolution, or 51% when the Kell factor is ignored.

A special signal tells the receiver when PALplus is in use, and also whether the original content was interlaced ("Camera mode" or 50i) or progressive scanned ("Film mode" or 25p) - see List of broadcast video formats. An additional signal can enable a "Ghost Cancellation" feature.

A separate feature related to PALplus is ColourPlus, which improves colour decoding performance. [2]

Extensions

The PALplus standard comprises three extensions to standard PAL: [42]

Vertical helper

A broadcaster creates a PALplus signal by scaling an anamorphic 16:9 picture with 576 lines down to 432 lines, so that the picture appears letterboxed on a regular PAL TV set. For luminance, the scaling is done using a pair of matching low-pass and high-pass filters, with the low-pass result being the regular PAL compatible letterbox broadcast. One out of every 4 lines of the high-pass result is hidden in the remaining 144 black letterbox lines at the top and bottom of the picture, using the U colour subcarrier. The filtering is such that this is enough to restore the complete 576 line resolution. The use of the colour subcarrier means these signals appear as very dark blue and yellow patterns on black bars on a regular 4:3 PAL TV set.

The 16:9 PAL-plus receiver combines 432 normally visible lines plus 144 helper lines, restoring the original 576 lines. In "Film mode" (progressive scan), this operation is performed on a per-frame basis, while in "Camera mode" (interlaced) the operation is performed per-field.

Colour-plus (or Clean PAL)

The PAL colour carrier is modulated making use of correlation between 2 fields, in order to give a cleaner luminance/chrominance separation in the PALplus receiver. It is used with signals with high horizontal luminance frequencies (3 MHz) that share the spectrum with the chrominance signals. Colour pictures on both standard and PALplus receivers are enhanced.

For progressive "Film mode" material, "Fixed" Colour-Plus is used, as there is no motion between the image fields. For camera based images, "Motion Adaptive Color-Plus" (MACP) is used based on movement.

Signaling bits

A special WSS signal tells the receiver whether 4:3/16:9/PALplus is in use, and also whether the original content was interlaced ("Camera mode") or progressive scanned ("Film mode"). An additional signal can enable a "Ghost Cancellation" feature. The bandwidth of these bits is low enough to be recorded on VHS and allow the receiver to switch to the proper format.

PALplus compatible sets

The standard permits using the mark "PALplus" if the vertical helper reconstruction is implemented, with Colour-plus being optional.

Some PALPlus compatible sets: [42]

PALPlus set top decoders: [43]

Most widescreen sets without any PALplus processing will switch the display format automatically between 4:3 and 16:9, based on the WSS signaling bits. These sets will simply zoom the centre 432 lines of the 16:9 letterboxed image to fill all of the 16:9 frame, without recovering any of the extra vertical line resolution.

See also

Related Research Articles

<span class="mw-page-title-main">Digital television</span> Television transmission using digital encoding

Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same bandwidth as a single analog channel, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2000. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widely used standards:

<span class="mw-page-title-main">NTSC</span> Analog television system

NTSC is the first American standard for analog television, published in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170.

<span class="mw-page-title-main">PAL</span> Colour encoding system for analogue television

Phase Alternating Line (PAL) is a colour encoding system for analog television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I or K. The articles on analog broadcast television systems further describe frame rates, image resolution, and audio modulation.

<span class="mw-page-title-main">Standard-definition television</span> Digital TV with similar definition to analog broadcasts

Standard-definition television is a television system that uses a resolution that is not considered to be either high or enhanced definition. Standard refers to offering a similar resolution to the analog broadcast systems used when it was introduced.

<span class="mw-page-title-main">Widescreen</span> Aspect ratio of a displayed image

Widescreen images are displayed within a set of aspect ratios 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 4:3 (1.33:1).

<span class="mw-page-title-main">ATSC standards</span> Standards for digital television in the US

Advanced Television Systems Committee (ATSC) standards are an International set of standards for broadcast and 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, South Korea and Trinidad & Tobago. Several former NTSC users, such as Japan, have not used ATSC during their digital television transition, because they adopted other systems such as ISDB developed by Japan, and DVB developed in Europe, for example.

Broadcasttelevision systems are the encoding or formatting systems for the transmission and reception of terrestrial television signals.

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 an extension of the standard-definition television (SDTV) format that enables a clearer picture during high-motion scenes compared to previous iterations of SDTV, but not producing images as detailed as high-definition television (HDTV).

Anamorphic widescreen is a process by which a comparatively wide widescreen image is horizontally compressed to fit into a storage medium with a narrower aspect ratio, reducing the horizontal resolution of the image while keeping its full original vertical resolution. Compatible play-back equipment 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.

<span class="mw-page-title-main">16:9 aspect ratio</span> Aspect ratio with a width of 16 units and height of 9 units

16:9 is a widescreen aspect ratio with a width of 16 units and height of 9 units.

In television technology, Wide Screen Signaling (WSS) is digital metadata embedded in invisible part of the analog TV signal describing qualities of the broadcast, in particular the intended aspect ratio of the image. This allows television broadcasters to enable both 4:3 and 16:9 television sets to optimally present pictures transmitted in either format, by displaying them in full screen, letterbox, widescreen, pillar-box, zoomed letterbox, etc.

HD-MAC was a broadcast television standard proposed by the European Commission in 1986, as part of Eureka 95 project. It belongs to the MAC - Multiplexed Analogue Components standard family. 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.

<span class="mw-page-title-main">Dot crawl</span>

Dot crawl is a visual defect of color analog video standards when signals are transmitted as composite video, as in terrestrial broadcast television. It consists of moving checkerboard patterns which appear along horizontal color transitions. It results from intermodulation or crosstalk between chrominance and luminance components of the signal, which are imperfectly multiplexed in the frequency domain.

<span class="mw-page-title-main">Philips circle pattern</span> TV test pattern, used to be widely used in European (PAL) countries

The Philips circle pattern refers to a family of related electronically generated complex television station colour test cards. The content and layout of the original colour circle pattern was designed by Danish engineer Finn Hendil (1939–2011) in the Philips TV & Test Equipment laboratory in Amager near Copenhagen under supervision of chief engineer Erik Helmer Nielsen in 1966–67, largely building on their previous work with the monochrome PM5540 pattern. The first piece of equipment, the PM5544 colour pattern generator, which generates the pattern, was made by Finn Hendil and his group in 1968–69. The same team would also develop the Spanish TVE colour test card in 1973.

<span class="mw-page-title-main">Multiplexed Analogue Components</span> 1980s analog television standard

Multiplexed Analogue Components (MAC) was an analog television standard where luminance and chrominance components were transmitted separately. This was an evolution from older color TV systems where there was interference between chrominance and luminance.

Analog high-definition television has referred to a variety of analog video broadcast television systems with various display resolutions throughout history.

MUSE, commercially known as Hi-Vision was a Japanese analog high-definition television system, with design efforts going back to 1979.

<span class="mw-page-title-main">Technology of television</span> Telecommunications, sound and video

The technology of television has evolved since its early days using a mechanical system invented by Paul Gottlieb Nipkow in 1884. Every television system works on the scanning principle first implemented in the rotating disk scanner of Nipkow. This turns a two-dimensional image into a time series of signals that represent the brightness and color of each resolvable element of the picture. By repeating a two-dimensional image quickly enough, the impression of motion can be transmitted as well. For the receiving apparatus to reconstruct the image, synchronization information is included in the signal to allow proper placement of each line within the image and to identify when a complete image has been transmitted and a new image is to follow.

High-definition television (HDTV) describes a television or video system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since at least 1933; in more recent times, it refers to the generation following standard-definition television (SDTV). It is currently the standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television.

Clear-Vision is a Japanese EDTV television system introduced in the 1990s, that improves audio and video quality while remaining compatible with the existing broadcast standard. Developed to improve analog NTSC, it adds features like progressive scan, ghost cancellation and widescreen image format. A similar system named PALPlus was develop in Europe with the goal of improving analog PAL broadcasts.

References

  1. 1 2 3 "Recommendation ITU-R BT.1197-1 Enhanced wide-screen PAL TV transmission system (the PALplus system)" (PDF). itu.int.
  2. 1 2 3 "Fluke PM5420 Application Note PALplus" (PDF). assets.fluke.com. Archived from the original (PDF) on 3 March 2016. Retrieved 12 January 2022.
  3. 1 2 "EUR-Lex - 31993D0424 - EN". Official Journal L 196. 5 August 1993. pp. 48–54.
  4. ↑ Nakayama, K.; Kojima, T.; Miyaguchi, H.; Sawaragi, T.; Yaguchi, Y. (August 5, 1995). "EDTV-II decoder by SVP2 (the 2nd generation of scan-line video processor)". IEEE Transactions on Consumer Electronics. 41 (3): 634–642. doi:10.1109/30.468089 – via IEEE Xplore.
  5. ↑ "The Journal of the Institute of Television Engineers of Japan". www.jstage.jst.go.jp.
  6. ↑ FUKINUKI, Takahiko (March 1991). "EDTV".
  7. ↑ Pollack, Andrew (September 15, 1994). "Japanese Taking to Wide-Screen TV". The New York Times– via NYTimes.com.
  8. ↑ "EDTV2 試験放送 画質評価用スライド放送" – via www.youtube.com.
  9. 1 2 Government of Canada, Public Works and Government Services Canada (8 October 2009). "D2-MAC [1 record] - TERMIUM Plus® — Search - TERMIUM Plus®". www.btb.termiumplus.gc.ca.
  10. ↑ ITU Radiocommunication Assembly (1992). Recommendation ITU-R BO.650-2 - Standards for conventional television systems for satellite broadcasting in the channels defined by Appendix 30 of the Radio Regulations (PDF). p. 18.
  11. ↑ Pauchon (1992). "Analogue HDTV in Europe". EBU Technical Review (PDF) (Autumn ed.). EBU. pp. 6–19.
  12. ↑ "D2-MAC [1 record] - TERMIUM Plus® — Search - TERMIUM Plus®". 8 October 2009.
  13. ↑ Gordon M. Drury, Garik Markarian, Keith Pickavance (11 April 2006). Coding and Modulation for Digital Television. Springer. ISBN   9780306470363.{{cite book}}: CS1 maint: multiple names: authors list (link)
  14. ↑ "EBU Technical Review - Analogue HDTV in Europe, Autumn 1992" (PDF).
  15. ↑ "Method for measuring, adjusting and/or equalizing transmission channels and/or television signal decoders".
  16. ↑ "HDTV on world stage. - Free Online Library". www.thefreelibrary.com.
  17. ↑ Ellis, R.J.G. (September 19, 1994). "The PALplus project: Conception to introduction". The PALpus project: conception to introduction. Vol. 1994. pp. 8–19. doi:10.1049/cp:19940720 – via IEEE Xplore.
  18. ↑ Second annual report on progress in Implementing the action plan for the introduction of advanced television services in Europe (PDF). Commission of the European Communities. 1996.
  19. 1 2 3 "Technology: Wide screens split BBC and Channel 4ry Fox". New Scientist.
  20. 1 2 "C4 Emits Widescreen Formats - The Media Leader". August 3, 1994.
  21. 1 2 "Recommendation ITU-R BT.1197-1: Enhanced wide-screen PAL TV transmission system (the PALplus system)".
  22. ↑ "» IFA - Internationale Funkausstellung - Berlin Guide in English". berlin.barwick.de.
  23. ↑ "BRT PALplus test card image". radio-tv-nederland.nl.
  24. ↑ "RTL-TVI Fermeture Antenne Mai 1997 + Mire PALPlus" – via www.youtube.com.
  25. ↑ "Belgium completes analogue switchover". Broadband TV News. February 8, 2010.
  26. ↑ "HIM Live @ MTV3 Jyrki Ville Valo Birthday 1999" – via www.youtube.com.
  27. ↑ "Plan E live interview @ MTV3 Jyrki (1999)" – via www.youtube.com.
  28. 1 2 "Nearly 50 Countries Switch Off Analog TV". ATSC : NextGen TV. July 7, 2015.
  29. ↑ "Astra ARD PAL Plus". October 8, 2021 – via Flickr.
  30. ↑ "Test Card Telefunken FuBK PALplus" – via www.youtube.com.
  31. ↑ "Television Graphics Around the World". www.meldrum.co.uk.
  32. ↑ "RTÉ announces the introduction of widescreen television broadcasting throughout the country on an experimental basis". RTÉ Archives.
  33. ↑ "Pal plus info 1998" – via www.youtube.com.
  34. ↑ "Testbeeld NOZEMA Ned 3 PALplus met radio 18-9-1998" – via www.youtube.com.
  35. ↑ "PalPlus na sylwestra - Gazeta Wyborcza". Archived from the original on 2015-10-04 – via archiwum.wyborcza.pl.
  36. ↑ "Premiera PALplus [16:9] w TVP - 31.12.1996 r." – via www.youtube.com.
  37. ↑ "4 TVI a Emitir em PAL PLUS 1994 Sozinho em Casa" – via www.youtube.com.
  38. ↑ "16:9". www.cinedie.com.
  39. ↑ "Spain". ing-sat.what.hu.
  40. ↑ "Los servicios interactivos en la Televisió de Catalunya". 1library.co.
  41. ↑ "UK completes TV switchover". BBC News.
  42. 1 2 "All You Ever Wanted to Know About PALplus but were Afraid to Ask". Archived from the original on 3 March 2016.
  43. ↑ "PALplus". www.pix.net.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.