PAL (an acronym for Phase Alternating Line) is a colour encoding system for analogue 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 (25 frames) per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I and K. The articles on analogue broadcast television systems further describe frame rates, image resolution, and audio modulation. PAL was developed by Walter Bruch at Telefunken in Hanover, West Germany, with important input from Gerhard Mahler. The format was patented by Telefunken in December 1962, citing Bruch as inventor, and unveiled to members of the European Broadcasting Union (EBU) on 3 January 1963. When asked why the system was named "PAL" and not "Bruch", the inventor answered that a "Bruch system" would probably not have sold very well ("Bruch" is the German word for "breakage").
Geographic reach PAL was adopted by most European countries, by some South American countries (Argentina, Brazil, Paraguay, Uruguay), by several African countries, including South Africa, and by most of Asia-Pacific (including the Middle East and South Asia). Countries in those regions that did not adopt PAL were France, Francophone Africa, several ex-Soviet states, Japan, South Korea, Liberia, Myanmar, the Philippines, and Taiwan. With the introduction of home video releases and later digital sources (e.g., DVD-Video), the name "PAL" might be used to refer to digital formats, even though they use completely different colour encoding systems. For instance, 576i (576 interlaced lines) digital video with colour encoded as YCbCr, intended to be backward compatible and easily displayed on legacy PAL devices, is usually mentioned as "PAL" (e.g., "PAL DVD"). Likewise, video game consoles outputting a 50 Hz signal might be labeled as "PAL", as opposed to 60 Hz on NTSC machines. These designations should not be confused with the analogue colour system itself.
History In the 1950s, Western European countries began plans to introduce colour television and were faced with the fact that the NTSC standard demonstrated several weaknesses, including colour tone shifting under poor transmission conditions, which became a major issue considering Europe's geographical and weather-related particularities. To overcome NTSC's shortcomings, alternative standards were devised, resulting in the development of the PAL and SECAM standards. The goal was to provide a colour TV standard for the European picture frequency of 50 fields per second (50 hertz), and finding a way to eliminate the problems with NTSC. PAL was developed by Walter Bruch at Telefunken in Hanover, West Germany, with important input from Gerhard Mahler. The format was patented by Telefunken in December 1962, citing Bruch as inventor, and unveiled to members of the European Broadcasting Union (EBU) on 3 January 1963. When asked why the system was named "PAL" and not "Bruch", the inventor answered that a "Bruch system" would probably not have sold very well ("Bruch" is the German word for "breakage"). The first broadcasts began in the United Kingdom in July 1967, followed by West Germany at the Berlin IFA on August 25. The BBC channel initially using the broadcast standard was BBC2, which had been the first UK TV service to introduce "625-lines" during 1964. The Netherlands and Switzerland started PAL broadcasts by 1968, with Austria following the next year. Telefunken PALcolour 708T was the first PAL commercial TV set. It was followed by Loewe-Farbfernseher S 920 and F 900. Telefunken was later bought by the French electronics manufacturer Thomson. Thomson also bought the Compagnie Générale de Télévision where Henri de France developed SECAM, the first European Standard for colour television. Thomson, now called Technicolour SA, also owns the RCA brand and licences it to other companies; Radio Corporation of America, the originator of that brand, created the NTSC colour TV standard before Thomson became involved. In Italy, at first Indesit in co-operation with SEIMART tried to develop its own standard, ISA (Identificazione a Soppressione Alternata). However, while it presented very interesting technical and qualitative characteristics, it arrived too late and its eventual adoption would have resulted in heavy political and economic consequences, therefore the system was abandoned in favor of PAL in 1975. The Soviet Union developed two further systems, mixing concepts from PAL and SECAM, known as TRIPAL and NIIR, that never went beyond tests. In 1993, an evolution of PAL aimed to improve and enhance format by allowing 16:9 aspect ratio broadcasts, while remaining compatible with existing television receivers, was introduced. Named PALplus, it was defined by ITU recommendation BT.1197-1. It was developed at the University of Dortmund in Germany, in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. Adoption was limited to European countries. With the introduction of digital broadcasts and signal sources (such as DVDs, game consoles), the term PAL was used imprecisely to refer to the 625-line/50 Hz television system in general, to differentiate from the 525-line/60 Hz system generally used with NTSC. For example, DVDs were labelled as PAL or NTSC (referring to the line count and frame rate) even though technically the discs carry neither PAL nor NTSC encoded signal. These devices would still have analog outputs (such as composite video output), and would convert the digital signals (576i or 480i) to the analog standards to assure compatibility. CCIR 625/50 and EIA 525/60 are the proper names for these (line count and field rate) standards; PAL and NTSC on the other hand are methods of encoding colour information in the signal.
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