PAL-M (television)
Encyclopedia
PAL-M is the TV system used in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 since February 19, 1972. At that time, Brazil was the first South American country to broadcast in colour. Colour TV broadcast began on September 1972 when the TV networks Globo, Tupi and Bandeirantes TV transmitted the Caxias do Sul
Caxias do Sul
Caxias do Sul is a city in Rio Grande do Sul, Southern Brazil, situated in the state's mountainous Serra Gaúcha region. Coordinates: 29°10′0″ S, 51°11′0″ W....

 Grape Festival
Festa da Uva
The Festa da Uva or GrapeFest is a biennial celebration of the Italian heritage and culture in the city of Caxias do Sul, state of Rio Grande do Sul, in southern Brazil. The Festa da Uva is held every even-numbered year in February...

. Transition from black and white to colour was not complete until 1977. Two years later, in 1979 colour broadcast nationwide in Brazil was commonplace

Technical specification

In Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...

 is used in conjunction with the 525 line, 30 frame/s system M, using (very nearly) the NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...

 colour subcarrier frequency. Almost all other countries using system M use NTSC.

Why PAL-M

NTSC being the "natural" choice for countries with monochrome standard M, the choice of a different colour system poses problems of incompatibility with available hardware and the need to develop new television sets and production hardware. Walter Bruch
Walter Bruch
Walter Bruch was a German engineer who invented the PAL color television system at Telefunken in the early 1960s. In Addition to his research activities Professor Bruch taught at Hannover Technical University. He was awarded the Werner-von-Siemens-Ring in 1975.-Biography:He was born at Neustadt an...

, inventor of PAL, explains Brazil's choice of PAL against these odds by an advertising campaign Telefunken
Telefunken
Telefunken is a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the Allgemeine Elektricitäts-Gesellschaft...

 and Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

 carried out across South America in 1972, which included colour test broadcasts of popular shows (done with TV Globo) and technical demonstrations with executives of television stations.

Compatibility

PAL-M signals are identical to North American NTSC signals, except for the encoding of the colour carrier. Therefore PAL-M will display in monochrome with sound on an NTSC set and vice versa.

PAL-M is incompatible with 625-line based versions of PAL
576i
576i is a standard-definition video mode used in PAL and SECAM countries. In digital applications it is usually referred to as "576i", in analogue contexts it is often quoted as "625 lines"...

, because its frame rate, scan line, colour subcarrier and sound carrier specifications are different. It will therefore usually give a rolling and/or squashed monochrome picture with no sound on a native European PAL television, as do NTSC signals.

PAL-M systems conversion issues

PAL-M being a standard unique to one country, the need of to convert it to/from other standards often arises.
  • Conversion to/from NTSC is easy, as only the colour carrier needs to be changed. Frame rate and scan lines can remain untouched.
  • Conversion to/from PAL/625 lines/25 frame/s and SECAM/625/25 signals involves changing the frame rates as well as the scan lines. This is achieved using complicated circuitry involving a digital frame store, the same method used for converting between NTSC and the 625/25 standards. The fact that the colour encoding of PAL-M and PAL/625/25 is the same does not help, as the entire signal goes through an A/D-D/A conversion process anyway.

PAL 60

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-like 525-line (480i
480i
480i is the shorthand name for a video mode, namely the US NTSC television system or digital television systems with the same characteristics. The i, which is sometimes uppercase, stands for interlaced, the 480 for a vertical frame resolution of 480 lines containing picture information; while NTSC...

) picture to form what is often known as "PAL-60" (sometimes "PAL-60/525" or "Pseudo PAL"). This non-standard signal is a cheap method used in European domestic VCRs and DVD players for playback of NTSC material on PAL televisions. It's not identical to PAL-M and incompatible with it, because the colour subcarrier is at a different frequency; it will therefore display in monochrome on PAL-M and NTSC television sets.

ABERT/SET tests

Before SBTVD, from 1999 to 2000, the ABERT/SET group in Brazil did system comparison tests of DTV under the supervision of the CPqD foundation.

The comparison tests were done under the direction of a work group of SET and ABERT
ABERT
ABERT is the Brazilian Association of Radio and Television Broadcasters . It was founded in 1962. The association has only two of the major television networks as members: Rede Globo and TV Record...

. The ABERT/SET group selected ISDB-T as the best system among ATSC, DVB-T and ISDB-T.

The outdoor coverage of field-tests result in "Brazilian digital television tests" show that ISDB-T is most robust system in Brazil.

SBTVD

The analog PAL-M is scheduled to be supplanted by a digital high-definition
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...

 system named Sistema Brasileiro de Televisão Digital
SBTVD
ISDB-T International or SBTVD, short for Sistema Brasileiro de Televisão Digital is a technical standard for digital television broadcast used in Brazil, Peru, Argentina, Chile, Venezuela, Ecuador, Costa Rica, Paraguay, Philippines, Bolivia, Nicaragua and Uruguay, based on the Japanese ISDB-T...

(SBTVD) by 2016.

See also

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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