Analog high-definition television systems
Encyclopedia
Historically, the term high-definition television was first used to refer to a analog video
broadcast television system
developed in the 1930s to replace early experimental systems with as few as 12-lines. On 2 November 1936 the BBC
began transmitting the world's first public regular high-definition television
(HDTV) service from the Victorian Alexandra Palace
in north London. It therefore claims to be the birthplace of television broadcasting as we know it today. Not long afterwards John Logie Baird
, Philo T. Farnsworth, and Vladimir Zworykin
had each developed competing TV systems, but resolution was not the issue that separated their substantially different technologies, it was patent interference
lawsuits and deployment issues given the tumultuous financial climate of the late '20s and '30s.
The British 405-line
system was the first to advertise itself as high-definition and see widespread use. Most patents were expiring by the end of World War II leaving the market wide open and no worldwide standard for television agreed upon. The standards introduced in the early 1950s stayed for over half a century.
resumed TV transmissions after WWII
, i.e., in the late 1940s and early 1950s, most countries standardized on a 576i
(625-line) television system. The two exceptions were the British 405-line
system, which had already been introduced in 1936, and the French
819-line system developed by René Barthélemy. During the 1940s Barthélemy reached 1015-lines and even 1042-lines. On November 20, 1948, future French president François Mitterrand
decreed a broadcast standard of 819-lines; broadcasting began at the end of 1949 in this definition.
The French TV system was arguably the world's first HDTV system, and, by today's standards, it could be called 737i (as it had 737-lines active) with a maximum theoretical resolution of 408 x 368-line pairs (which in digital terms can be expressed as equivalent to 816x737 pixels) with a 4:3 aspect ratio. It was used only in France by TF1
, along with Tele Monte Carlo in Monaco
. However, the theoretical picture quality far exceeded the capabilities of the equipment of its time, and each 819-line channel occupied a wide 14 MHz of VHF bandwidth.
To have an idea of the quality :
the modern 720p standard is 1280x720 pixels , of which the 4:3 portion would be 960x720 pixels.
A PAL DVD is encoded 720*576 pixels.
Television channel
s were arranged as follows:
Technical specifications of the broadcast television systems used with 819-lines.
System E implementation provided very good (near HDTV) picture quality but with an uneconomical use of bandwidth.
In addition, an adapted 819-line system known as System F was used in Belgium and Luxembourg. It allowed French 819-line programming to be broadcast on the 7 MHz VHF channels used in those countries, with a substantial cost in horizontal resolution (408*737). It was discontinued in Belgium in February 1968, and in Luxembourg in September 1971.
Despite some attempts to create a color SECAM
version of the 819-line system, France abandoned it in favor of the Europe-wide standard of 625-lines (576i50), with the final 819-line transmissions from Paris in 1984. TMC in Monaco were the last broadcasters to transmit 819-line television, closing down their System E transmitter in 1985.
From the French government's point of view, the 819-line TV system had the great advantage that it prevented French citizens from being able to receive 'inappropriate' broadcasts from foreign countries. The switch to the accepted European wide 625-line standard looked to undermine that advantage, but this was sidestepped by adopting positive video modulation when the rest of the world had switched to negative modulation with all its advantages.
Howewer, in France between 1976 and 1981 when French TF1
was switching area by area to the new analog 625-lines UHF network with SECAM color, some transmitters and gapfillers have provisory broadcasted the 819-lines signal in UHF. When switching to 625-lines most gapfillers were not changed UHF channel.
Example: many gapfillers using this transmission located in French Alps near Grenoble, Mont Salève and Geneva. They began broadcasting in UHF channel 42, and continued to use this frequency until today. They were simply switched to 625-lines in June 1981.
signals in the late 1980s using an interlaced resolution of 1035 or 1080-lines active (1035i) or 1125-lines total supported by the Sony HDVS
line of equipment.
The Japanese system, developed by NHK Science & Technology Research Laboratories in the 1980s, employed filtering tricks to reduce the original source signal to decrease bandwidth utilization. MUSE was marketed as "Hi-Vision" by NHK.
In the typical setup, three picture elements on a line were actually derived from three separate scans. Stationary images were transmitted at full resolution. However, as MUSE lowers the horizontal and vertical resolution of material that varies greatly from frame to frame, moving images were blurred in a manner similar to using 16 mm movie film for HDTV projection. In fact, whole-camera pans would result in a loss of 50% of horizontal resolution.
MUSE's "1125-lines" are an analog measurement, which includes non-video "scan lines" during which a CRT
's electron beam returns to the top of the screen to begin scanning the next field. Only 1035-lines have picture information. Digital signals count only the lines (rows of pixels) of the picture makeup as there are no other scanning lines (though conversion to an analogue format will introduce them), so NTSC's 525-lines become 480i, and MUSE would be 1035i (or 1080i, hence the origin of less than ideal 1080 for digital HDTV. 960p60 for USA and 1152i25 for Europe and 1152p48 worldwide would be better).
Shadows and multipath still plague this analog frequency modulated transmission mode.
Considering the technological limitations of the time, MUSE was a very cleverly-designed analog system.
Though Japan has since switched to a digital HDTV system based on ISDB, the original MUSE-based BS Satellite channel 9 (NHK BS Hi-vision) was still being broadcast . It broadcast the same programs as BS-digital channel 103, but transmission ended on November 30, 2007.
in 1986 (MAC standard) . It was an early attempt by the EEC to provide HDTV
in Europe
. It was a complex mix of analog signal
(Multiplexed Analog Components) multiplexed with digital sound. The video signal (1250 (1152 visible) lines/50 frames in 16:9
aspect ratio) was encoded with a modified D2-MAC encoder.
In the 1992 Summer Olympics
experimental HD-MAC broadcasting took place. 100 HD-MAC receivers (in that time, retroprojectors) in Europe were used to test the capabilities of the standard. This project was financed by the European Union
(EU). The PAL-converted signal was used by mainstream broadcasters such as SWR
, BR
and 3Sat
.
The HD-MAC standard was abandoned in 1993, and since then all EU and EBU
efforts have focused on the DVB system (Digital Video Broadcasting), which allows both SDTV and HDTV.
Related standards
Analog video
Analog video is a video signal transferred by an analog signal. An analog color video signal contains luminance, brightness and chrominance of an analog television image...
broadcast television system
Broadcast television system
Broadcast television systems are encoding or formatting standards for the transmission and reception of terrestrial television signals. There are three main analog television systems in current use around the world: NTSC, PAL, and SECAM...
developed in the 1930s to replace early experimental systems with as few as 12-lines. On 2 November 1936 the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
began transmitting the world's first public regular high-definition television
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...
(HDTV) service from the Victorian Alexandra Palace
Alexandra Palace
Alexandra Palace is a building in North London, England. It stands in Alexandra Park, in an area between Hornsey, Muswell Hill and Wood Green...
in north London. It therefore claims to be the birthplace of television broadcasting as we know it today. Not long afterwards John Logie Baird
John Logie Baird
John Logie Baird FRSE was a Scottish engineer and inventor of the world's first practical, publicly demonstrated television system, and also the world's first fully electronic colour television tube...
, Philo T. Farnsworth, and Vladimir Zworykin
Vladimir Zworykin
Vladimir Kozmich Zworykin was a Russian-American inventor, engineer, and pioneer of television technology. Zworykin invented a television transmitting and receiving system employing cathode ray tubes...
had each developed competing TV systems, but resolution was not the issue that separated their substantially different technologies, it was patent interference
Interference proceeding
An interference proceeding, also known as priority contest, is an inter partes proceeding to determine the priority issues of multiple patent applications. It is a unique procedure in the patent law of the United States. Unlike in most other countries which have adopted the first-to-file system,...
lawsuits and deployment issues given the tumultuous financial climate of the late '20s and '30s.
The British 405-line
405-line
The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting....
system was the first to advertise itself as high-definition and see widespread use. Most patents were expiring by the end of World War II leaving the market wide open and no worldwide standard for television agreed upon. The standards introduced in the early 1950s stayed for over half a century.
French 819-line (737i) system
When EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
resumed TV transmissions after WWII
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, i.e., in the late 1940s and early 1950s, most countries standardized on a 576i
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"...
(625-line) television system. The two exceptions were the British 405-line
405-line
The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting....
system, which had already been introduced in 1936, and the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
819-line system developed by René Barthélemy. During the 1940s Barthélemy reached 1015-lines and even 1042-lines. On November 20, 1948, future French president François Mitterrand
François Mitterrand
François Maurice Adrien Marie Mitterrand was the 21st President of the French Republic and ex officio Co-Prince of Andorra, serving from 1981 until 1995. He is the longest-serving President of France and, as leader of the Socialist Party, the only figure from the left so far elected President...
decreed a broadcast standard of 819-lines; broadcasting began at the end of 1949 in this definition.
The French TV system was arguably the world's first HDTV system, and, by today's standards, it could be called 737i (as it had 737-lines active) with a maximum theoretical resolution of 408 x 368-line pairs (which in digital terms can be expressed as equivalent to 816x737 pixels) with a 4:3 aspect ratio. It was used only in France by TF1
TF1
TF1 is a national French TV channel, controlled by TF1 Group, whose major share-holder is Bouygues. TF1's average market share of 24% makes it the most popular domestic network...
, along with Tele Monte Carlo in Monaco
Monaco
Monaco , officially the Principality of Monaco , is a sovereign city state on the French Riviera. It is bordered on three sides by its neighbour, France, and its centre is about from Italy. Its area is with a population of 35,986 as of 2011 and is the most densely populated country in the...
. However, the theoretical picture quality far exceeded the capabilities of the equipment of its time, and each 819-line channel occupied a wide 14 MHz of VHF bandwidth.
To have an idea of the quality :
the modern 720p standard is 1280x720 pixels , of which the 4:3 portion would be 960x720 pixels.
A PAL DVD is encoded 720*576 pixels.
Television channel
Television channel
A television channel is a physical or virtual channel over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video and...
s were arranged as follows:
| Ch | picture (MHz) | sound (MHz) |
|---|---|---|
| F2 | 52.40 | 41.25 |
| F4 | 65.55 | 54.40 |
| F5 | 164.00 | 175.15 |
| F6 | 173.40 | 162.25 |
| F7 | 177.15 | 188.30 |
| F8 | 186.55 | 175.40 |
| F8a | 185.25 | 174.10 |
| F9 | 190.30 | 201.45 |
| F10 | 199.70 | 188.55 |
| F11 | 203.45 | 214.60 |
| F12 | 212.85 | 201.70 |
Technical specifications of the broadcast television systems used with 819-lines.
| Field frequency | Active picture | Field blanking | No. of broad pulses | Broad pulse width | Line frequency | Front porch | Line sync | Back porch | Active line time | Video/syncs ratio |
|---|---|---|---|---|---|---|---|---|---|---|
| 50 Hz | 737-lines | 41-lines | 1 per field | 20.0 µs | 20475 Hz | 0.5 µs | 2.5 µs | 5.0 µs | 40.8 µs | 70/30 |
| System | Lines | Frame rate | Channel bandwidth (in MHz) | Visual bandwidth (in MHz) | Sound offset | Vestigial sideband | Vision mod. | Sound mod. |
|---|---|---|---|---|---|---|---|---|
| System E | 819 | 25 | 14 | 10 | ±11.15 (Sound carrier separation +11.15 MHz on odd numbered channels, -11.15 MHz on even numbered channels.) | 2.00 | Pos. | AM |
| System F | 819 | 25 | 7 | 5 | +5.5 | 0.75 | Pos. | AM |
System E implementation provided very good (near HDTV) picture quality but with an uneconomical use of bandwidth.
In addition, an adapted 819-line system known as System F was used in Belgium and Luxembourg. It allowed French 819-line programming to be broadcast on the 7 MHz VHF channels used in those countries, with a substantial cost in horizontal resolution (408*737). It was discontinued in Belgium in February 1968, and in Luxembourg in September 1971.
Despite some attempts to create a color SECAM
SECAM
SECAM, also written SÉCAM , is an analog color television system first used in France....
version of the 819-line system, France abandoned it in favor of the Europe-wide standard of 625-lines (576i50), with the final 819-line transmissions from Paris in 1984. TMC in Monaco were the last broadcasters to transmit 819-line television, closing down their System E transmitter in 1985.
From the French government's point of view, the 819-line TV system had the great advantage that it prevented French citizens from being able to receive 'inappropriate' broadcasts from foreign countries. The switch to the accepted European wide 625-line standard looked to undermine that advantage, but this was sidestepped by adopting positive video modulation when the rest of the world had switched to negative modulation with all its advantages.
Howewer, in France between 1976 and 1981 when French TF1
TF1
TF1 is a national French TV channel, controlled by TF1 Group, whose major share-holder is Bouygues. TF1's average market share of 24% makes it the most popular domestic network...
was switching area by area to the new analog 625-lines UHF network with SECAM color, some transmitters and gapfillers have provisory broadcasted the 819-lines signal in UHF. When switching to 625-lines most gapfillers were not changed UHF channel.
Example: many gapfillers using this transmission located in French Alps near Grenoble, Mont Salève and Geneva. They began broadcasting in UHF channel 42, and continued to use this frequency until today. They were simply switched to 625-lines in June 1981.
Multiple sub-nyquist sampling Encoding system (MUSE)
Japan had the earliest working HDTV system, with design efforts going back to 1979. The country began broadcasting wideband analog high-definition videoHigh-definition video
High-definition video or HD video refers to any video system of higher resolution than standard-definition video, and most commonly involves display resolutions of 1,280×720 pixels or 1,920×1,080 pixels...
signals in the late 1980s using an interlaced resolution of 1035 or 1080-lines active (1035i) or 1125-lines total supported by the Sony HDVS
Sony HDVS
Sony HDVS was a range of high-definition video equipment developed in the 1980s to support an early analog high-definition television system thought to be the broadcast television systems that would be in use today...
line of equipment.
The Japanese system, developed by NHK Science & Technology Research Laboratories in the 1980s, employed filtering tricks to reduce the original source signal to decrease bandwidth utilization. MUSE was marketed as "Hi-Vision" by NHK.
- Japanese broadcast engineers immediately rejected conventional vestigial sideband broadcasting for well-founded technical reasons.
- It was decided early on that MUSE would be a satellite broadcast format as Japan economically supports satellite broadcasting.
In the typical setup, three picture elements on a line were actually derived from three separate scans. Stationary images were transmitted at full resolution. However, as MUSE lowers the horizontal and vertical resolution of material that varies greatly from frame to frame, moving images were blurred in a manner similar to using 16 mm movie film for HDTV projection. In fact, whole-camera pans would result in a loss of 50% of horizontal resolution.
MUSE's "1125-lines" are an analog measurement, which includes non-video "scan lines" during which a CRT
Cathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
's electron beam returns to the top of the screen to begin scanning the next field. Only 1035-lines have picture information. Digital signals count only the lines (rows of pixels) of the picture makeup as there are no other scanning lines (though conversion to an analogue format will introduce them), so NTSC's 525-lines become 480i, and MUSE would be 1035i (or 1080i, hence the origin of less than ideal 1080 for digital HDTV. 960p60 for USA and 1152i25 for Europe and 1152p48 worldwide would be better).
Shadows and multipath still plague this analog frequency modulated transmission mode.
Considering the technological limitations of the time, MUSE was a very cleverly-designed analog system.
Though Japan has since switched to a digital HDTV system based on ISDB, the original MUSE-based BS Satellite channel 9 (NHK BS Hi-vision) was still being broadcast . It broadcast the same programs as BS-digital channel 103, but transmission ended on November 30, 2007.
HD-MAC
HD-MAC was a proposed television standard by the European CommissionEuropean Commission
The European Commission is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union's treaties and the general day-to-day running of the Union....
in 1986 (MAC standard) . It was an early attempt by the EEC to provide HDTV
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...
in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. It was a complex mix of analog signal
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
(Multiplexed Analog Components) multiplexed with digital sound. The video signal (1250 (1152 visible) lines/50 frames in 16:9
16:9
16:9 is an aspect ratio with a width of 16 units and height of 9. Since 2009, it has become the most common aspect ratio for sold televisions and computer monitors and is also the international standard format of HDTV, Full HD, non-HD digital television and analog widescreen television ...
aspect ratio) was encoded with a modified D2-MAC encoder.
1992 Summer Olympics
The 1992 Summer Olympic Games, officially known as the Games of the XXV Olympiad, were an international multi-sport event celebrated in Barcelona, Catalonia, Spain, in 1992. The International Olympic Committee voted in 1986 to separate the Summer and Winter Games, which had been held in the same...
experimental HD-MAC broadcasting took place. 100 HD-MAC receivers (in that time, retroprojectors) in Europe were used to test the capabilities of the standard. This project was financed by the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
(EU). The PAL-converted signal was used by mainstream broadcasters such as SWR
SWR
SWR may refer to:Technology:* Standing wave ratio, a wave and antenna concept* Steel Wire ropeRadio stations:* Südwestrundfunk, a public broadcasting company for the southwest of Germany...
, BR
BR
- Places :* Bedroom* BR postcode area, a group of eight postal districts in southeast London* Baton Rouge, Louisiana* Brazil , according to:** Its two-letter country code defined in ISO 3166-1 alpha-2** The prefix for Brazil's ISO 3166-2 subdivision codes...
and 3Sat
3sat
3sat is the name of a public, advertising-free, television network in Central Europe. The programming is in German and is broadcast primarily within Germany, Austria and Switzerland .3sat was established for cultural...
.
The HD-MAC standard was abandoned in 1993, and since then all EU and EBU
European Broadcasting Union
The European Broadcasting Union is a confederation of 74 broadcasting organisations from 56 countries, and 49 associate broadcasters from a further 25...
efforts have focused on the DVB system (Digital Video Broadcasting), which allows both SDTV and HDTV.
See also
The analog TV systems these systems were meant to replace- SECAMSECAMSECAM, also written SÉCAM , is an analog color television system first used in France....
- NTSCNTSCNTSC, 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...
- PALPALPAL, 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...
Related standards
- NICAMNICAMNear Instantaneous Companded Audio Multiplex is an early form of lossy compression for digital audio. It was originally developed in the early 1970s for point-to-point links within broadcasting networks...
-like audio coding is used in the HD-MAC system. - Chroma subsamplingChroma subsamplingChroma subsampling is the practice of encoding images by implementing less resolution for chroma information than for luma information, taking advantage of the human visual system's lower acuity for color differences than for luminance....
in TV indicated as 4:2:2, 4:1:1 etc...
External links
- http://819lignes.free.fr/index.html Restore operation on a French 1951 TV set (French language only)
- HDTV coverage of the Barcelona Olympic Games by M. Romero and E. Gavilan (EBU)
- The HDTV demonstrations at the Expo 92 *Broken Link* by J.L. Tejerina and F. Visintin (EBU)
- European Broadcasting Union
- COUNCIL DIRECTIVE 92/38/EEC of 11 May 1992.