PAL-M (television)
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PAL-M is the TV system used in Brazil since February 19, 1972. At that time, Brazil was the first country in South America with broadcasting in color. Rede Bandeirantes passed to PAL-M that year, while other television stations - like Rede Globo and Tupi - made a progressive and slow transition to PAL-M, only completed in 1977. In 1979 black-and-white programs were no longer broadcast -- transition was completed.
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In Brazil, PAL is used in conjunction with the 525 line, 29.97 frame/s system M, using (very nearly) the NTSC colour subcarrier frequency. Almost all other countries using system M use NTSC.
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, inventor of PAL, explains Brazil's choice of PAL against these odds by an advertising campaign Telefunken and Philips did 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. [1]
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 all other flavours of PAL, 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 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 fps 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.
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) 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'll therefore display in monochrome on PAL-M and NTSC television sets.
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. 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.
The analog PAL-M is scheduled to be supplanted by a digital high-definition system named Sistema Brasileiro de Televisão Digital (SBTVD) by 2016.
- ^ PAL Das Farbfernsehen; Walter Bruch/Heide Riedel; Deutsches Rundfunk-Museum 1987
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| Designation |
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| Low; MP@LL |
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| Standard; MP@ML |
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| Enhanced |
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| High; MP@HL |
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| Ultra High |
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| This table illustrates total horizontal and vertical pixel resolution via box size. It does not accurately reflect the screen shape (aspect ratio) of these formats, which is either 4:3, or 16:9. | ||||||||
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| Analog broadcast | 525 lines: NTSC • NTSC-J • PAL-M
625 lines: PAL • PAL-N • PALplus • SECAM Defunct systems: Pre-1940 • 405 lines • 819 lines • Baird-Nipkow • MAC • MUSE Multichannel audio: BTSC (MTS) • NICAM-728 • Zweiton (A2, IGR) • EIAJ Hidden signals: Captioning • Teletext • CGMS-A • GCR • PDC • VBI • VEIL • VITC • WSS • XDS |
| Digital broadcast | Interlaced: SDTV (480i, 576i) • HDTV (1080i)
Progressive: LDTV (240p, 288p, 1seg) • EDTV (480p, 576p) • HDTV (720p, 1080p) Digital TV standards (MPEG-2):ATSC, DVB, ISDB, DMB-T/H Digital TV standards (MPEG-4 AVC):DMB-T/H,DVB,SBTVD,ISDB (1seg) Multichannel audio: AC3 (5.1) • Musicam • PCM • LPCM • AAC Hidden signals: Captioning • Teletext • (CPCM/Broadcast flag) • AFD • EPG Digital cinema: UHDV (2540p, 4320p) • DCI |
| Technical issues | 14:9 • MPEG transport • Standards conversion • Video processing • VOD • HDTV blur |