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PAL

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Analog television encoding systems by nation:NTSC(green),SECAM(orange), and PAL (blue)

Phase Alternating Line(PAL) is a colour encoding system foranalog television.It was one of three major analogue colour television standards, the others beingNTSCandSECAM.In most countries it was broadcast at625 lines,50 fields (25 frames) per second, and associated with CCIR analoguebroadcast television systemsB,D,G,H,IorK.The articles on analogbroadcast television systemsfurther describeframe rates,image resolution,and audio modulation.

PAL video iscomposite videobecauseluminance(luma, monochrome image) andchrominance(chroma, colour applied to the monochrome image) are transmitted together as one signal.

A latter evolution of the standard,PALplus,added support forwidescreenbroadcasts with no loss of verticalimage resolution,while retaining compatibility with existing sets. Almost all of the countries using PAL are currently in theprocess of conversion,or have already converted transmission standards toDVB,ISDBorDTMB.

Geographic reach[edit]

PAL was adopted by most European countries, by several African countries, byArgentina,Brazil,Paraguay,Uruguay,and by most ofAsia Pacific (including the Middle East and South Asia).[1]Countries in those regions that did not adopt PAL wereFrance,[2]Francophone Africa,[2]several ex-Sovietstates,[2]Japan,[3]South Korea,Liberia,Myanmar,thePhilippines,[3]andTaiwan.[3]

PAL region[edit]

With the introduction ofhome videoreleases 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 asYCbCr,intended to be backward compatible and easily displayed on legacy PAL devices, is usually mentioned as "PAL" (eg: "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 analog colour system itself.

History[edit]

In the 1950s, the Western European countries began plans to introduce colour television, and were faced with the problem that theNTSCstandard 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 50fieldsper second (50hertz), and finding a way to eliminate the problems with NTSC.

PAL was developed byWalter BruchatTelefunkenin Hanover,West Germany,with important input fromGerhard Mahler[de].[4]The format was patented byTelefunkenin December 1962, citing Bruch as inventor,[5][6]and unveiled to members of theEuropean Broadcasting Union(EBU) on 3 January 1963.[6]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"[7]).

The first broadcasts began in theUnited Kingdomin July 1967, followed byWest Germanyat theBerlin IFAon August 25.[6][8]The BBC channel initially using the broadcast standard wasBBC2,which had been the first UK TV service to introduce "625-lines" during 1964. TheNetherlandsandSwitzerlandstarted PAL broadcasts by 1968, withAustriafollowing the next year.[6]

Telefunken PALcolour 708T[9]was the first PAL commercial TV set. It was followed byLoewe-Farbfernseher S 920andF 900.[10]

Telefunken was later bought by the French electronics manufacturerThomson.Thomson also bought theCompagnie Générale de TélévisionwhereHenri de Francedeveloped SECAM, the firstEuropean Standardfor colour television. Thomson, now called Technicolour SA, also owns theRCA brandand licences it to other companies;Radio Corporation of America,the originator of that brand, created the NTSC colour TV standard before Thomson became involved.

TheSovietsdeveloped two further systems, mi xing concepts from PAL and SECAM, known as TRIPAL and NIIR, that never went beyond tests.[6]

In 1993,[11]an evolution of PAL aimed to improve and enhance format by allowing16:9aspect ratiobroadcasts, while remaining compatible with existing television receivers,[12]was introduced. NamedPALplus,it was defined byITUrecommendation BT.1197-1. It was developed at theUniversity of DortmundinGermany,in cooperation with German terrestrial broadcasters and European and Japanese manufacturers. Adoption was limited to European countries.

With the introduction ofdigital broadcastsand signal sources (ex:DVDs,game consoles), the term PAL was used imprecisely to refer to the625-line/50 Hz television system in general, to differentiate from the525-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)[13]even though technically the discs carry neither PAL nor NTSC encoded signal. These devices would still have analog outputs (ex;composite videooutput), and would convert the digital signals (576ior480i) 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.

Color decoding methods[edit]

"PAL-D", "PAL-N", "PAL-H" and "PAL-K" designations on this section describe PAL decoding methods and are unrelated tobroadcast systemswith similar names.[6]

The Telefunken licence covered any decoding method that relied on the alternating subcarrier phase to reduce phase errors, described as "PAL-D"for" delay ", and"PAL-N"for" new "or"Chrominance Lock".[6]

This excluded very basic PAL decoders that relied on the human eye to average out the odd/even line phase errors, and in the early 1970s some Japanese set manufacturers developed basic decoding systems to avoid paying royalties toTelefunken.These variations are known as "PAL-S"(for" simple "or" Volks-PAL "),[14]operating without a delay line and suffering from the “Hannover bars”effect. An example of this solution is theKuba Porta Color CK211Pset.[6]Another solution was to use a 1Hanalogue delay lineto allow decoding of only the odd or even lines. For example, the chrominance on odd lines would be switched directly through to the decoder and also be stored in the delay line. Then, on even lines, the stored odd line would be decoded again. This method (known as 'gated NTSC') was adopted bySonyon their 1970sTrinitronsets (KV-1300UBtoKV-1330UB), and came in two versions: "PAL-H"and"PAL-K"(averaging over multiple lines).[6][14]It effectively treated PAL as NTSC, suffering from hue errors and other problems inherent in NTSC and required the addition of a manualhuecontrol.

Colour encoding[edit]

Un-decoded PAL image, showing chroma information as fine patternschroma dots(click to zoom) overlapping the luma signal
Decoded PAL image, with chroma fully recovered. Some minor artifacts (seedot crawl) are present across transition areas (click to zoom)

Most PAL systems encode the colour information using a variant of theY'UVcolour space.comprises the monochromelumasignal, with the three RGB colour channels mixed down onto two,and.

Like NTSC, PAL uses aquadrature amplitude modulatedsubcarriercarrying thechrominanceinformation added to the luma video signal to form acomposite videobaseband signal. The frequency of this subcarrier is 4.43361875MHzfor PAL 4.43, compared to 3.579545 MHz for NTSC 3.58. The SECAM system, on the other hand, uses a frequency modulation scheme on its two line alternate colour subcarriers 4.25000 and 4.40625 MHz.

The name "Phase Alternating Line" describes the way that the phase of part of the colour information on the video signal is reversed with each line, which automatically corrects phase errors in the transmission of the signal by cancelling them out, at the expense of vertical frame colour resolution. Lines where the colour phase is reversed compared to NTSC are often called PAL or phase-alternation lines, which justifies one of the expansions of the acronym, while the other lines are called NTSC lines. Early PAL receivers relied on the human eye to do that cancelling; however, this resulted in a comb-like effect known asHanover barson larger phase errors. Thus, most receivers now use a chrominanceanalogue delay line,which stores the received colour information on each line of display; an average of the colour information from the previous line and the current line is then used to drive thepicture tube.The effect is that phase errors result insaturationchanges, which are less objectionable than the equivalent hue changes of NTSC. A minor drawback is that the vertical colour resolution is poorer than the NTSC system's, but since the human eye also has a colour resolution that is much lower than its brightness resolution, this effect is not visible. In any case, NTSC, PAL, and SECAM all have chrominance bandwidth (horizontal colour detail) reduced greatly compared to the luma signal.

Spectrum of a System I television channel with PAL.
RF spectrogram andwaterfallof an actual PAL-I transmission withNICAM.
Oscillogram of composite PAL signal—one frame.
Oscillogram of composite PAL signal—several lines.
Oscillogram of composite PAL signal—two lines.
Awaterfall displayshowing a 20ms long interlaced PAL frame with high FFT resolution
Analyzing a PAL signal and decoding the 20ms frame and 64 μs lines

The 4.43361875 MHz frequency of the colour carrier is a result of 283.75 colour clock cycles per line plus a 25 Hz offset to avoid interferences. Since the line frequency (number of lines per second) is 15625 Hz (625 lines × 50 Hz ÷ 2), the colourcarrier frequencycalculates as follows: 4.43361875 MHz = 283.75 × 15625 Hz + 25 Hz.

The frequency 50 Hz is the optional refresh frequency of the monitor to be able to create an illusion of motion, while 625 lines means the vertical lines or resolution that the PAL system supports.

The original colourcarrieris required by the colour decoder to recreate thecolour differencesignals. Since the carrier is not transmitted with the video information it has to be generated locally in the receiver. In order that thephaseof this locally generated signal can match the transmitted information, a 10 cycle burst of coloursubcarrieris added to the video signal shortly after the line sync pulse, but before the picture information, during the so-calledback porch.This colour burst is not actually in phase with the original colour subcarrier, but leads it by 45 degrees on the odd lines and lags it by 45 degrees on the even lines. Thisswinging burstenables the colour decoder circuitry to distinguish the phase of thevector which reverses every line.

PAL signal details[edit]

For PAL-B/G the signal has these characteristics.

Parameter Value
Bandwidth 5 MHz[15]
Horizontal sync polarity Negative
Total time for each line 64μs[16][17]
Front porch(A) 1.65+0.4
−0.1
μs
Sync pulse length (B) 4.7±0.20 μs
Back porch(C) 5.7±0.20 μs
Active video (D) 51.95+0.4
−0.1
μs

(Total horizontal sync time 12.05 μs)

After 0.9 μs a2.25±0.23 μscolourburstof10±1cycles is sent. Most rise/fall times are in250±50nsrange. Amplitude is 100% for white level, 30% for black, and 0% for sync.[16]

TheCVBSelectrical amplitude is Vpp1.0Vand impedance of 75Ω.[18]

Thecomposite video(CVBS) signal used in systems M and N before combination with a sound carrier andmodulationonto anRFcarrier.

The vertical timings are:

Parameter Value
Vertical lines 312.5 (625 total)
Vertical lines visible 288 (576 total)
Vertical sync polarity Negative (burst)
Vertical frequency 50 Hz
Sync pulse length (F) 0.576ms(burst)[19]
Active video (H) 18.4 ms

(Total vertical sync time 1.6 ms)

As PAL is interlaced, every two fields are summed to make a complete picture frame.

Colorimetry[edit]

PAL colorimetry, as defined by the ITU on REC-BT.470, and based onCIE 1931x,y coordinates:[20]

PAL colorimetry
Standard Year White point Primaries DisplaygammaEOTF
Red Green Blue
PAL EBU3213-E,ITU-R BT.470/601 (B/G) 1970 D65 0.64 0.33 0.29 0.60 0.15 0.06 2.8
PAL-M BT.470-6[21] 1972 C 0.67 0.33 0.21 0.71 0.14 0.08 2.2

The assumeddisplay gammais defined as 2.8.[20]ThePAL-Msystem uses color primary and gamma values similar to NTSC.[21]Color is encoded using theYUVcolor space.

Luma() is derived from red, green, and blue () gamma pre-corrected () primary signals:[17]

andare used to transmitchrominance.Each has a typical bandwidth of 1.3 MHz.

Composite PAL signaltiming[17]where.

Subcarrier frequencyis 4.43361875 MHz (±5 Hz) for PAL-B/D/G/H/I/N.

PAL broadcast systems[edit]

The PAL colour system is usually used with a video format that has 625 lines per frame (576 visible lines, the rest being used for other information such as sync data and captioning) and arefresh rateof 50interlacedfields per second (compatible with 25 full frames per second), such systems beingB,G,H,I,andN(seebroadcast television systemsfor the technical details of each format).

This ensures video interoperability. However, as some of these standards (B/G/H,IandD/K) use different sound carriers (5.5 MHz, 6.0 MHz and 6.5 MHz respectively), it may result in a video image without audio when viewing a signal broadcast over the air or cable. Some countries inEastern Europewhich formerly usedSECAMwith systemsDandKhave switched to PAL while leaving other aspects of their video system the same, resulting in the different sound carrier. Instead, other European countries have changed completely from SECAM-D/K to PAL-B/G.[22]

The PAL-N system has a different sound carrier, and also a different colour subcarrier, and decoding on incompatible PAL systems results in a black-and-white image without sound.

The PAL-M system has a different sound carrier and a different colour subcarrier, and does not use 625 lines or 50 frames/second. This would result in no video or audio at all when viewing a European signal.

Differences between PAL variants[20]
PAL B PAL G, H PAL I PAL D/K, L PAL N PAL M
Transmission band VHF UHF VHF/UHF
Fields 50 60
Scan lines 625 525
Active lines 576 480
Channel bandwidth 7 MHz 8 MHz 6 MHz
Video bandwidth 5.0 MHz 5.5 MHz 6.0 MHz 4.2 MHz
Vision/Sound carrier spacing 5.5 MHz 6.0 MHz 6.5 MHz 4.5 MHz
ColourSubcarrier 4.43361875 MHz 3.58205625 MHz 3.575611 MHz
Assumed Receiver
Gamma correction
2.8 2.2

System A[edit]

The BBC tested their pre-war (but still broadcast until 1985)405-linemonochrome system (CCIR System A) with all three colour standards including PAL, before the decision was made to abandon 405 and transmit colour on 625/System Ionly.

PAL-B/G/D/K/I[edit]

Many countries have turned off analogue transmissions, so the following does not apply anymore, except for using devices which output RF signals, such asvideo recorders.

The majority of countries using or having used PAL have television standards with 625 lines and 50 fields per second. Differences concern the audio carrier frequency and channel bandwidths. The variants are:

  • Standards B/Gare used in most of Western Europe, former Yugoslavia, South Asia, Australia, and New Zealand
  • Standard Iin the UK, Ireland, Hong Kong, South Africa, and Macau
  • Standards D/K(along with SECAM usually) in most of Central and Eastern Europe and mainland China.Most analogue CCTV cameras are Standard D.[citation needed]

Systems B and G are similar. System B specifies 7 MHz channel bandwidth, while System G specifies 8 MHz channel bandwidth. Australia and China used Systems B and D respectively for VHF and UHF channels. Similarly, Systems D and K are similar except for the bands they use: System D is only used on VHF, while System K is only used on UHF. Although System I is used on both bands, it has only been used on UHF in the United Kingdom.

PAL-L[edit]

The PAL-L (Phase Alternating Line withCCIR System Lbroadcast system) standard uses the same video system as PAL-B/G/H (625 lines, 50 Hz field rate, 15.625 kHz line rate), but with a larger 6 MHz video bandwidth rather than 5.5 MHz and moving the audio subcarrier to 6.5 MHz. An 8 MHz channel spacing is used for PAL-L, to maintain compatibility with System L channel spacings.

PAL-N (Argentina, Paraguay and Uruguay)[edit]

The PAL-N standard was created inArgentina,through Resolution No. 100 ME/76,[23]which determined the creation of a study commission for a national color standard. The commission recommended using PAL underCCIR System NthatParaguayandUruguayalso used. It employs the 625 line/50 field per second waveform of PAL-B/G, D/K, H, and I, but on a 6 MHz channel with a chrominance subcarrier frequency of 3.582056 MHz (917/4*H) similar to NTSC (910/4*H).[20]On the studio production level, standard PAL cameras and equipment were used, with video signals then transcoded to PAL-N for broadcast.[24]This allows 625 line, 50 frames per second video to be broadcast in a 6 MHz channel, at some cost inhorizontal resolution.

PAL-M (Brazil)[edit]

In Brazil, PAL is used in conjunction with the 525 line, 60 field/sCCIR System M,using (very nearly) the NTSC colour subcarrier frequency. Exact colour subcarrier frequency of PAL-M is 3.575611 MHz, or 227.25 times System M's horizontal scan frequency. Almost all other countries using system M use NTSC.

The PAL colour system (either baseband or with any RF system, with the normal 4.43 MHz subcarrier unlike PAL-M) can also be applied to an NTSC-like525-linepicture to form what is often known as "PAL 60" (sometimes "PAL 60/525", "Quasi-PAL" or "Pseudo PAL" ). PAL-M (a broadcast standard) however should not be confused with "PAL 60" (a video playback system—see below).

Home devices[edit]

Multisystem TVs[edit]

PAL television receivers manufactured since the 1990s can typically decode all of the PAL variants except, in some cases PAL-M and PAL-N. Many such receivers can also receive Eastern European and Middle Eastern SECAM, though rarely French-broadcast SECAM (because France used a quasi-unique positive video modulation, system L) unless they are manufactured for the French market. They will correctly display plain (non-broadcast)CVBSorS-videoSECAM signals. Many can also acceptbasebandNTSC-M, such as from a VCR or game console, and RF modulated NTSC with a PAL standard audio subcarrier (i.e., from a modulator), though not usually broadcast NTSC (as its 4.5 MHz audio subcarrier is not supported). Many sets also support NTSC with a 4.43 MHz color subcarrier (see PAL 60 on the next section).

VHS and DVD players[edit]

VHStapes recorded from a PAL-N or a PAL-B/G, D/K, H, or I broadcast are indistinguishable because the downconverted subcarrier on the tape is the same. A VHS recorded off TV (or released) in Europe will play in colour on any PAL-N VCR and PAL-N TV in Argentina, Paraguay and Uruguay. Likewise, any tape recorded in Argentina, Paraguay or Uruguay off a PAL-N TV broadcast can be sent to anyone in European countries that use PAL (and Australia/New Zealand, etc.) and it will display in colour. This will also play back successfully in Russia and other SECAM countries, as the USSR mandated PAL compatibility in 1985—this has proved to be very convenient for video collectors.

People in Argentina, Paraguay and Uruguay usually own TV sets that also display NTSC-M, in addition to PAL-N.DirecTValso conveniently broadcasts in NTSC-M for North, Central, and South America. MostDVDplayers sold in Argentina, Paraguay and Uruguay also play PAL discs—however, this is usually output in the European variant (colour subcarrier frequency 4.433618 MHz), so people who own a TV set which only works in PAL-N (plus NTSC-M in most cases) will have to watch those PAL DVD imports in black and white (unless the TV supports RGBSCART) as the colour subcarrier frequency in the TV set is the PAL-N variation, 3.582056 MHz.

In the case that a VHS or DVD player works in PAL (and not in PAL-N) and the TV set works in PAL-N (and not in PAL), there are two options:

  • images can be seen in black and white, or
  • an inexpensivetranscoder(PAL -> PAL-N) can be purchased in order to see the colours

Some DVD players (usually lesser known brands) include an internal transcoder and the signal can be output in NTSC-M, with some video quality loss due to thestandard conversionfrom a 625/50 PAL DVD to the NTSC-M 525/60 output format. A few DVD players sold in Argentina, Paraguay and Uruguay also allow a signal output of NTSC-M, PAL, or PAL-N. In that case, a PAL disc (imported from Europe) can be played back on a PAL-N TV because there are no field/line conversions, quality is generally excellent.

Some special VHS video recorders are available which can allow viewers the flexibility of enjoying PAL-N recordings using a standard PAL (625/50 Hz) colour TV, or even through multi-system TV sets. Video recorders like Panasonic NV-W1E (AG-W1 for the US), AG-W2, AG-W3, NV-J700AM, Aiwa HV-M110S, HV-M1U, Samsung SV-4000W and SV-7000W feature a digital TV system conversion circuitry.

PAL 60[edit]

Many 1990s-onwardsvideocassette recorderssold in Europe can play back NTSC tapes. When operating in this mode most of them do not output a true (625/50) PAL signal, but rather a hybrid consisting of the original NTSC line standard (525/60), with colour converted to PAL 4.43 MHz (instead of 3.58 as with NTSC and South American PAL variants and with the PAL-specific phase alternation of colour difference signal between the lines) — this is known as"PAL 60"(also"quasi-PAL"or"pseudo-PAL") with "60" standing for 60 Hz (for 525/30), instead of 50 Hz (for 625/25).

Some video game consoles also output a signal in this mode. TheDreamcastpioneered PAL 60 with most of its games being able to play games at full speed like NTSC and without borders.XboxandGameCubealso support PAL 60 unlike PlayStation 2.[25]ThePlayStation 2did not actually offer a true PAL 60 mode; while many PlayStation 2 games did offer a "PAL 60" mode as an option, the console would in fact generate an NTSC signal during 60 Hz operation.

Most newer television sets can display a "PAL 60" signal correctly, but some will only do so (if at all) in black and white and/or with flickering/foldover at the bottom of the picture, or picture rolling (however, many old TV sets can display the picture properly by means of adjusting the V-Hold and V-Height knobs—assuming they have them). Some TV tuner cards or video capture cards will support this mode (although software/driver modification can be required and the manufacturers' specs may be unclear).

Some DVD players offer a choice of PAL vs NTSC output for NTSC discs.[26]

PAL vs. NTSC[edit]

PAL usually has 576 visible lines compared with 480 lines withNTSC,meaning that PAL has a 20% higher resolution, in fact it even has a higher resolution thanEnhanced Definitionstandard (852x480). Most TV output for PAL and NTSC use interlaced frames meaning that even lines update on one field and odd lines update on the next field. Interlacing frames gives a smoother motion with half the frame rate.NTSCis used with aframe rateof60ior30pwhereas PAL generally uses50ior25p;both use a high enoughframe rateto give the illusion of fluid motion. This is due to the fact that NTSC is generally used in countries with autility frequencyof 60 Hz and PAL in countries with 50 Hz, although there are many exceptions.

Both PAL and NTSC have a higher frame rate than film which uses 24 frames per second. PAL has a closer frame rate to that of film, so most films are sped up 4% to play on PAL systems, shortening the runtime of the film and, without adjustment, slightly raising the pitch of the audio track. Film conversions for NTSC instead use3:2 pull downto spread the 24 frames of film across 60 interlaced fields. This maintains the runtime of the film and preserves the original audio, but may cause worse interlacing artefacts during fast motion.

NTSC receivers have atint controlto perform colour correction manually. If this is not adjusted correctly, the colours may be faulty. The PAL standard automatically cancelshueerrors by phase reversal, so a tint control is unnecessary yet Saturation control can be more useful. Chrominance phase errors in the PAL system are cancelled out using a 1H delay line resulting in lower saturation, which is much less noticeable to the eye than NTSC hue errors.

However, the alternation of colour information—Hanover bars—can lead to picture grain on pictures with extreme phase errors even in PAL systems, if decoder circuits are misaligned or use the simplified decoders of early designs (typically to overcome royalty restrictions). This effect will usually be observed when the transmission path is poor, typically in built up areas or where the terrain is unfavourable. The effect is more noticeable on UHF than VHF signals as VHF signals tend to be more robust. In most cases such extreme phase shifts do not occur.

PAL and NTSC have slightly divergentcolour spaces,but the colour decoder differences here are ignored.

Outside of film and TV broadcasts, the differences between the two formats when used in the context ofvideo gamesare quite dramatic. For comparison, the NTSC standard is 60 fields/30 frames per second while PAL is 50 fields/25 frames per second. To avoid timing problems or unfeasible code changes, games were slowed down by approximately 16.7%. This has led to games ported over to PAL regions being historically known for their inferior speed and frame rates compared to their NTSC counterparts.Full motion videorendered and encoded at 30 frames per second by the Japanese/US (NTSC) developers were often down-sampled to 25 frames per second or considered to be 50 frames per second video for PAL release—usually by means of3:2 pull-down,resulting in motionjudder.In addition to this, the increased resolution of PAL was often not utilised at all during conversion, creating a pseudo-letterbox effect with borders on the top and bottom of the screen, looking similar to 14:9 letterbox. This leaves the graphics with a slightly squashed look due to an incorrect aspect ratio caused by the borders. This practice was prevalent in previous generations, especially during the8-bitand16-bitera of games where 2D graphics were the norm at that time. The gameplay of many games with an emphasis on speed, such as the originalSonic the Hedgehogfor theSega Genesis (Mega Drive),suffered in their PAL incarnations.

Starting with thesixth generationof video games, game consoles started to offer true 60 Hz modes in games ported to PAL regions. TheDreamcastwas the first to offer a true "PAL 60" mode, and games made for the system in PAL regions offered no significant differences compared to their NTSC counterparts in terms of speed and frame rates. TheXboxandGameCubealso featured "PAL 60" modes in games made for the region as well. The lone exception was thePlayStation 2,where games ported over to PAL regions are oftentimes (but not always) running in 50 Hz modes. PAL region games supporting 60 Hz modes for the PlayStation 2 also required a display with NTSC capability unlessRGBorcomponentconnections were utilized, as these allowed colour outputs without the need for NTSC or PAL colour encoding. Otherwise, the games would display in monochrome on PAL-only displays.

The problems usually associated with PAL region video games aren't necessarily encountered in Brazil with the PAL-M standard used in that region, since its video system uses an identical number of visible lines and refresh rate as NTSC but with a slightly different colour encoding frequency based on PAL, modified for use with theCCIR System Mbroadcast television system.

PAL vs. SECAM[edit]

TheSECAMpatents predate those of PAL by several years (1956 vs. 1962). Its creator, Henri de France, in search of a response to known NTSChueproblems, came up with ideas that were to become fundamental to both European systems, namely:

  1. colour information on two successive TV lines is very similar and vertical resolution can be halved without serious impact on perceived visual quality
  2. more robust colour transmission can be achieved by spreading information on two TV lines instead of just one
  3. information from the two TV lines can be recombined using a delay line.

SECAM applies those principles by transmitting alternately only one of the U and V components on each TV line, and getting the other from the delay line. QAM is not required, andfrequency modulationof the subcarrier is used instead for additional robustness (sequential transmission of U and V was to be reused much later in Europe's last "analog" video systems: the MAC standards).

SECAM is free of both hue and saturation errors. It is not sensitive to phase shifts between the colour burst and the chrominance signal, and for this reason was sometimes used in early attempts at colour video recording, where tape speed fluctuations could get the other systems into trouble. In the receiver, it did not require a quartz crystal (which was an expensive component at the time) and generally could do with lower accuracy delay lines and components.

SECAM transmissions are more robust over longer distances than NTSC or PAL. However, owing to their FM nature, the colour signal remains present, although at reduced amplitude, even in monochrome portions of the image, thus being subject to stronger cross colour.

One serious drawback for studio work is that the addition of two SECAM signals does not yield valid colour information, due to its use of frequency modulation. It was necessary to demodulate the FM and handle it as AM for proper mi xing, before finally remodulating as FM, at the cost of some added complexity and signal degradation. In its later years, this was no longer a problem, due to the wider use of component and digital equipment.

PAL can work without a delay line (PAL-S), but this configuration, sometimes referred to as "poor man's PAL", could not match SECAM in terms of picture quality. To compete with it at the same level, it had to make use of the main ideas outlined above, and as a consequence PAL had to pay licence fees to SECAM. Over the years, this contributed significantly to the estimated 500 million francs gathered by the SECAM patents (for an initial 100 million francs invested in research).[27]

Hence, PAL could be considered as a hybrid system, with its signal structure closer to NTSC, but its decoding borrowing much from SECAM.

There were initial specifications to use colour with the French 819 line format (system E). However, "SECAM E" only ever existed in development phases. Actual deployment used the 625 line format. This made for easy interchange and conversion between PAL and SECAM in Europe. Conversion was often not even needed, as more and more receivers and VCRs became compliant with both standards, helped in this by the common decoding steps and components. When theSCARTplug became standard, it could take RGB as an input, effectively bypassing all the colour coding formats' peculiarities.

When it comes to home VCRs, all video standards use what is called "colour under" format. Colour is extracted from the high frequencies of the video spectrum, and moved to the lower part of the spectrum available from tape. Luma then uses what remains of it, above the colour frequency range. This is usually done by heterodyning for PAL (as well as NTSC). But the FM nature of colour in SECAM allows for a cheaper trick: division by 4 of the subcarrier frequency (and multiplication on replay). This became the standard for SECAM VHS recording in France. Most other countries kept using the same heterodyning process as for PAL or NTSC and this is known as MESECAM recording (as it was more convenient for some Middle East countries that used both PAL and SECAM broadcasts).

Another difference in colour management is related to the proximity of successive tracks on the tape, which is a cause for chroma crosstalk in PAL. A cyclic sequence of 90° chroma phase shifts from one line to the next is used to overcome this problem. This is not needed in SECAM, as FM provides sufficient protection.

Regarding early (analogue) videodiscs, the established Laserdisc standard supported only NTSC and PAL. However, a different optical disc format, the Thomson transmissive optical disc made a brief appearance on the market. At some point, it used a modified SECAM signal (single FM subcarrier at 3.6 MHz[28]). The media's flexible and transmissive material allowed for direct access to both sides without flipping the disc, a concept that reappeared in multi-layered DVDs about fifteen years later.

Countries and territories that are using or once used PAL[edit]

Below are lists of countries and territories that used or once used the PAL system. Many of these have converted or are converting PAL toDVB-T(most countries),DVB-T2(most countries),DTMB(China, Hong Kong and Macau) orISDB-Tb(Sri Lanka, Maldives, Botswana, Brazil, Argentina, Paraguay and Uruguay).

A legacy list of PAL users in 1998 is available onRecommendation ITU-R BT.470-6 - Conventional Television Systems, Appendix 1 To Annex 1.[29]

Using PAL B, D, G, H, K or I[edit]

PAL-M[edit]

  • Brazil(Simulcast in ISDB-Tb started on December 2, 2007. PAL broadcasting in its final stages of abandonment, the complete shutdown is scheduled to 2025.)

PAL-N[edit]

  • Argentina(Simulcast in ISDB-Tb started on August 28, 2008. PAL broadcasting in its final stages of abandonment, the complete shutdown is scheduled to 2025.)
  • Paraguay(Simulcast in ISDB-Tb)
  • Uruguay(Simulcast in ISDB-Tb)

Countries and territories that have ceased using PAL[edit]

The following countries and territories no longer use PAL for terrestrial broadcasts, and are in process of converting from PAL toDVB-T/T2,DTMBorISDB-T.

Country Switched to Switchover completed
Albania DVB-T2 2019-10-011 October 2019
Andorra DVB-T 2007-09-2525 September 2007
Australia DVB-T 2013-12-1010 December 2013
Austria DVB-TandDVB-T2 2010-06-077 June 2011
Azerbaijan DVB-T 2015-06-1717 June 2015
Belgium DVB-T 2010-03-011 March 2010
Brunei DVB-T 2015-01-011 January 2015
Bulgaria DVB-T 2013-09-3030 September 2013
Cambodia DVB-T2 2015-01-011 January 2015
China DTMB 2021-03-3131 March 2021
Croatia DVB-T2 2020-11-1212 November 2020[32]
Cyprus DVB-T 2011-07-011 July 2011
Czech Republic DVB-TandDVB-T2 2012-06-3030 June 2012
Denmark DVB-TandDVB-T2 2009-11-011 November 2009
Estonia DVB-T 2010-07-011 July 2010
Faroe Islands DVB-T 2002–12December 2002
Finland DVB-TandDVB-T2 2007-09-011 September 2007
Georgia DVB-T 2015-07-011 July 2015
Germany DVB-TandDVB-T2 2009-06-044 June 2009
Ghana DVB-T2 2015-06June 2015
Greece DVB-T 2015-02-056 February 2015
Gibraltar DVB-T 2012-12-3131 December 2012
Guernsey DVB-T 2010-11-1717 November 2010
Hong Kong DTMB 2020-12-011 December 2020
Hungary DVB-TandDVB-T2 2013-10-3131 October 2013
Iceland DVB-TandDVB-T2 2015-02-022 February 2015
India DVB-T 2015-03-3131 March 2015
Indonesia DVB-T2 2023-08-1212 August 2023[33]
Iran DVB-T 2014-12-1919 December 2014
Ireland DVB-T 2012-10-2424 October 2012
Isle of Man DVB-T 2012-10-2424 October 2012
Israel DVB-TandDVB-T2 2011-06-1313 June 2011
Italy DVB-T 2012-07-044 July 2012
Jersey DVB-T 2010-11-1717 November 2010
Kenya DVB-T 2015-03March 2015
Latvia DVB-T 2010-06-011 June 2010
Lithuania DVB-T 2012-10-2929 October 2012
Luxembourg DVB-T 2006-09-011 September 2006
Macau DTMB 2023-06-3030 June 2023[34]
North Macedonia DVB-T 2013-05-3131 May 2013
Malaysia DVB-T2 2019-10-3131 October 2019
Malta DVB-T 2011-10-3131 October 2011
Monaco DVB-T 2011-05-2424 May 2011
Montenegro DVB-T 2015-06-1717 June 2015
Namibia DVB-T 2014-09-1313 September 2014
Netherlands DVB-T 2006-12-1414 December 2006
New Zealand DVB-T 2013-12-011 December 2013
Norway DVB-T 2009-12December 2009[35]
Poland DVB-T 2013-07-2323 July 2013
Portugal DVB-T 2012-04-2626 April 2012
Qatar DVB-TandDVB-T2 2012-02-1313 February 2012
Romania DVB-T2 2016-12-3131 December 2016
Rwanda DVB-T 2014-03March 2014
San Marino DVB-T 2010-12-022 December 2010
Saudi Arabia DVB-TandDVB-T2 2012-02-1313 February 2012
Serbia DVB-T2 2015-06-077 June 2015
Singapore DVB-T2 2019-01-022 January 2019
Slovakia DVB-T 2012-12-3131 December 2012
Slovenia DVB-T 2010-12-011 December 2010
Spain DVB-TandDVB-T2 2010-04-033 April 2010
Sweden DVB-TandDVB-T2 2007-10-2929 October 2007
Switzerland DVB-T 2007-11-2626 November 2007
Tanzania DVB-T 2014-07July 2014
Thailand DVB-T2 2020-03-2626 March 2020
Ukraine DVB-TandDVB-T2 2016-12-3131 December 2016
United Arab Emirates DVB-TandDVB-T2 2012-02-1313 February 2012
United Kingdom DVB-T(SD) andDVB-T2(HD) 2012-10-2424 October 2012
Vietnam DVB-T2 2020-12-2828 December 2020
Zambia DVB-T2 2014-12-3131 December 2014

See also[edit]

References[edit]

  1. ^"PGC categories – Countries using PAL standard".22 April 2009. Archived fromthe originalon 22 April 2009.
  2. ^abc"PGC categories – Countries using SECAM standard".23 February 2009. Archived fromthe originalon 23 February 2009.
  3. ^abc"PGC categories – Countries using NTSC standard".22 April 2009. Archived fromthe originalon 22 April 2009.
  4. ^"Walter Bruch and the PAL Color Television System".2 March 2020.Retrieved6 July2021.In 1963, when he gave a public presentation of the Phase Alternation Line to a group of experts from the European Broadcasting Union in Hannover
  5. ^"Walter Bruch; PAL Television".7 December 2019.Retrieved14 July2021.In 1950s, when Telefunken commissioned Bruch to invent an automated differential phase correction for color television. That's why he was awarded.
  6. ^abcdefghi"45 Years Anniversary of Walter Bruch's PAL Color Television".radiomuseum.org.
  7. ^"English translation of 'Bruch'".Collins German to English Dictionary.
  8. ^The standard that defines the PAL system was last published by theInternational Telecommunication Unionin 1998 and has the titleRecommendation ITU-R BT.470, Conventional Television Systems
  9. ^"Telefunken PALcolour 708 TV advert".radiomuseum.org.
  10. ^"Loewe-Farbfernseher S 920 & F 900 PAL TV advert".buizenradioclub.nl.
  11. ^"EUR-Lex – 31993D0424 – EN".Official Journal L 196.5 August 1993. pp. 48–54.
  12. ^"Fluke PM5420 Application Note PALplus"(PDF).assets.fluke.Archived fromthe original(PDF)on 3 March 2016.Retrieved12 January2022.
  13. ^"What Is a NTSC Format DVD? How Can I Play a NTSC DVD in the UK Without Restriction?".videoconverterfactory.
  14. ^ab"Tech Notes: Colour TV".16 July 2007. Archived fromthe originalon 16 July 2007.Retrieved21 October2022.
  15. ^"PGC categories – Countries using PAL standard".Archived fromthe originalon 22 April 2009.090426 dvd-replica
  16. ^ab"Horizontal Blanking Interval of 405-, 525-, 625- and 819-Line Standards"(PDF).Archived fromthe original(PDF)on 29 May 2009.090426 pembers.freeserve.co.uk
  17. ^abc"NTSC, PAL, and SECAM Overview"(PDF).p. 52. Archived fromthe original(PDF)on 7 July 2012.Retrieved26 April2009.
  18. ^LDK 5400 Triax Adapter Technical Manual(PDF).Thomson Multimedia Broadcast Solutions. 2002.
  19. ^"Vertical Blanking Interval of 625-Line Standard (PAL Colour)"(PDF).Archived fromthe original(PDF)on 28 April 2016.Retrieved3 September2015.
  20. ^abcd"Recommendation ITU-R BT.470-6 - Conventional Television Systems"(PDF).
  21. ^ab"Recommendation ITU-R BT.470-6 - Conventional Television Systems, p.16"(PDF).
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  23. ^"La TV se muda"(PDF)(in Spanish).Retrieved3 April2024.
  24. ^Iazbec; Soria; Tulli; Gonzalez (1999).Estudio de las tecnicas de transcodificacion de señales de television PAL-B / PAL-N(in Spanish). Vol. 10. Centro de Informacion Tecnologica. pp. 341–349.
  25. ^"The Virtual Console's PAL Problem".15 April 2010.
  26. ^"Playback of NTSC Videos on PAL Equipment".Retrieved29 June2019.
  27. ^"The CCIR, the standards and the TV sets' market in France" (section III.1)
  28. ^"Les Videodisques", Georges Broussaud (head/member of development team), editions Masson
  29. ^Recommendation ITU-R BT.470-6 - Conventional Television Systems(PDF).ITU Radiocommunication Assembly. 1998. pp. 29–34.
  30. ^abcdefghijklmnopqrstuvwxyzaaabacadaeafagahaiajakalamanaoapaqarasatauavMichael Hegarty; Anne Phelan; Lisa Kilbride (1 January 1998).Classrooms for Distance Teaching and Learning: A Blueprint.Leuven University Press.pp. 260–.ISBN978-90-6186-867-5.
  31. ^"PAL / NTSC / SECAM countries list".Archived fromthe originalon 21 February 2016.Retrieved9 December2017.
  32. ^"Prijelaz na DVB-T2 TV signal s HEVC (H.265) sažimanjem | OIV digitalni signali i mreže".gledajbezbrige.oiv.hr(in Croatian).Retrieved2 January2024.
  33. ^"Siaran TV Analog Disetop di Seluruh RI 12 Agustus 2023".detik.Retrieved22 September2023.
  34. ^"TDM to switch off analogue television transmission system".TDM.Retrieved13 July2023.
  35. ^"TV og radio".17 March 2020.

External links[edit]