The following explanations relate to the PAL and NTSC systems, but correspondingly apply to video signals of other standards and non-standardized signals.
The colour subcarrier frequency (fsc) of a PAL system and a NTSC system is fsc(NTSC) = 3.58 MHz or fsc(PAL) = 4.43 MHz.
In addition, in PAL and NTSC systems the relationships of the colour subcarrier frequency (fsc) to the line frequency (fh) are given by fsc(NTSC) = 227.50 * fh or 4•fsc(NTSC) = 910 • fh fsc(PAL) = 283.75 * fh or 4•fsc(PAL) = 1135 • fh so that the phase of the colour subcarrier in the case of NTSC is changed by 180°/line and in PAL by 270°/line.
The invention relates to a digital multistandard decoder for video signals and to a method for decoding video signals. Colour video signals, so-called composite video, blanking and sync signals (CVBS) (chroma-video-blanking-sync) signal is a signal comprising both the chrominance and the luminance component of the video signal. Therefore, the CVBS video signal may be PAL video signal, a SECAM video signal, or an NTSC video signal. are essentially composed of a brightness signal or luminance component (Y), two colour difference signals or chrominance components (U, V or I, Q), vertical and horizontal sync signals (VS, HS) and a blanking signal (BL).
In order to decode a video signal and restore a color image, a color TV set has to identify the color TV standard used at the emission. Conventional color TV sets are equipped with a system for automatically identifying the norm or standard of the color TV set used for the emission. The invention more particularly relates to an automatic method for identifying a color TV standard in a multistandard TV set.
Presently, the most commonly used color TV standards are PAL, NTSC and SECAM standards. For these three standards, each line of the composite video signal comprises a synchronization pulse, a burst of a few oscillations of the chrominance sub-carrier signal, then the signal itself corresponding to the image, comprising superimposed luminance and chrominance information, the latter information being carried by the luminance signal.
The characteristics of the chrominance sub-carrier in the various PAL, NTSC and SECAM standards are defined in the published documents concerning these standards and will not be described in detail here. However, the main characteristics of these various standards will be briefly reminded because these indications are useful for a better understanding of the invention.
In the PAL standard, the frequency of the chrominance sub-carrier is equal for all the lines, but the phase of one of the modulation vectors varies + or -90° from one line to another. The frequency of the chrominance sub-carrier is standardized at 4.43 Mhz. In this system, the burst signal is also shifted by + or -90° from one line to the next.
In the NTSC standard, the chrominance sub-carrier is equal for all the lines.
In the SECAM standard, one uses two chrominance sub-carrier frequencies which alternate from one line to another, at 4.25 Mhz and 4.40 Mhz, respectively. These two chrominance sub-carriers are frequency modulated.
The multistandard color TV sets must have distinct internal systems designed to decode the luminance and chrominance signals for each standard used.
Therefore, these TV sets have to previously identify the received standard.
Systems for automatically identifying the standard used already exist. Generally, for such an automatic standard identification, the systems known use the bursts of the chrominance sub-carrier signal that are present at the beginning of each line. In fact, these bursts are standardized and calibrated samples of the chrominance sub-carrier transmitted on the video signal and comprise all the characteristic information concerning the transmitted color standard. The information contained in these bursts represents the frequency, the phase of one of the modulation vectors and the frequency or phase variation of one line with repect to the next one.
The set features a Toshiba Black Matrix CRT TUBE .
Victor Company of Japan, Ltd (Nippon Bikutā Kabushiki-gaisha?) (TYO: 6792), usually referred to as JVC, is a Japanese international consumer and professional electronics corporation based in Yokohama, Japan which was founded in 1927. The company is best known for introducing Japan's first televisions, and developing the VHS video recorder.
1920s – 1960s
JVC was founded in 1927 as "The Victor Talking Machine Company of Japan, Limited" as a subsidiary of the United States' leading phonograph and record company, the Victor Talking Machine Company. In 1929 majority ownership was transferred to RCA-Victor. In the 1930s JVC produced phonographs and records, but in 1932 JVC started producing radios, and in 1939 they introduced Japan's first TV. JVC severed relations with its foreign partners during World War II, and was majority owned by Matsushita (Panasonic Corp.) from 1953 to Aug 2007. Finally it became JVC Kenwood Holdings in 2008 after Panasonic (Matsushita) decided to spin off the company and it was merged with Kenwood Electronics.
1970s – 1980s
In 1970, JVC marketed the Videosphere, a modern portable CRT television inside a space helmet shaped casing with an alarm clock at the base. It was a commercial success.
In 1971, JVC introduced the first discrete system for four channel quadraphonic sound sound on vinyl records - CD-4 (Compatible Discrete Four Channel) or Quadradisc, as it was called by RCA in the U.S. In 1976 JVC introduced the 3060, a 3" portable television with an included cassette player.
VC developed the VHS format, and introduced the first VHS recorders to the consumer market in 1977 for the equivalent of US $1060. Sony who had introduced the Betamax home videocassette tape a year earlier, became the main competitor to JVC's VHS into the 1980s creating the videotape format war. The Betamax cassette was smaller with slightly superior quality to the VHS cassette, but this resulted in Betamax having less recording time. By 1984, forty companies utilized the VHS format in comparison with Betamax's twelve. Sony tacitly conceded defeat in 1988 when they also began producing VHS recorders.
In 1979, JVC demonstrated a prototype of their VHD/AHD disc system. This system was capacitance-based like CED, but the discs were grooveless with the stylus being guided by servo signals in the disc surface. The VHD discs were initially handled by the operator and played on a machine that looked like an audio LP turntable, but JVC used caddy housed discs when the system was marketed. Development was interrupted continually, but in April 1983 it was first marketed in Japan, and then in the UK in 1984 to a limited industrial market. By this time both Philips and Sony already had compact discs on the market, and the VHD format never caught on.
In 1981, JVC introduced a line of revolutionary direct drive cassette decks, topped by the DD-9, that provided previously unattainable levels of speed stability.
During the 1980s JVC had a brief appearance in marketing their own portable audio equipment similar to the Sony Walkmans at the time. The JVC CQ-F2K was released in 1982 and had a detachable radio that mounted to the headphones for compact, wire-free listening experience. JVC had difficulty making a success of the products, and a few years later abandoned the product line. In Japan, JVC marketed the products under the name Victor.
In 1986, JVC released the HC-95, a personal computer with a 3.58 MHz Zilog Z80A processor, 64KB RAM and ran MSX Basic 2.0. It included two 3.5" floppy disk drives and conformed to the graphics specification of the MSX-2 standard. However, like the Pioneer PX-7 it also carried a sophisticated hardware interface that handled video superimposition and various interactive video processing features. The JVC HC-95 was first sold in Japan, and then Europe, but sales were disappointing.
JVC video recorders were marketed by Ferguson in the UK, with just cosmetic changes. However Ferguson needed to find another supplier for its camcorders when JVC produced only the VHS-C format, rather than video8. Furthermore, Ferguson was taken over by Thomson SA and so ended the relationship. At the time, JVC had a reputation for reliable, high quality equipment. JVC has gone on to invent hard drive camcorders.
In October 2001, the National Academy of Television Arts and Sciences presented JVC an Emmy Award for "outstanding achievement in technological advancement" for “Pioneering Development of Consumer Camcorders.” Annual sponsorships of the world-renowned JVC Tokyo Video Festival and the JVC Jazz Festival have helped attract the attention of more customers.
JVC has been a worldwide football supporter since 1982, having a former kit sponsorship with Arsenal and continued its role as an official partner of 2002 FIFA World Cup Korea / Japan. JVC made headlines as the first-ever corporate partner of the Kennedy Space Center Visitor Complex. JVC has recently forged elite corporate partnerships with ESPN Zone and with Foxploration. In 2005, JVC joined HANA, the High-Definition Audio-Video Network Alliance to help establish standards in consumer electronics interoperability.
JVC developed the first DVD+RW DL in 2005.
In December 2006, Matsushita entered talks with Kenwood and Cerberus Capital Management to sell its stake in JVC.
In 2007, Victor Company of Japan Ltd confirmed a strategic capital alliance with Kenwood and SPARKX Investment, resulting in Matsushita shareholding being reduced to approx 37%.
In 2008, Matsushita (Panasonic) agreed to spin-off the company and merge with Kenwood Electronics, creating JVC Kenwood Holdings, formed on October 1, 2008.