EXCHANGING VHS CASSETTES WITH FOREIGN VIEWERS AND
\n USING VHS RECORDERS ABROAD<\/p>\n
INTRODUCTION<\/p>\n
Exchanging any video program with someone living abroad is complicated by
\nthe fact that most of the world does not use the American TV system.
\nRegardless of the tape format used (i.e., VHS, SVHS, Beta, 8 mm, etc.)
\nforeign video recordings cannot be played on an incompatible player, or
\ndisplayed on an incompatible TV receiver.<\/p>\n
I will try to describe here some “tips and traps” of exchanging video
\nrecordings with foreign viewers and on using your NTSC camcoder in foreign
\ncountries. Since the VHS home recording system predominates at-present, I
\nwill describe here only the specific problems that relate to VHS.
\nSince the SVHS format differs only in the way in which the luminance
\ninformation is separated and recorded, all of the information below applies
\nequally to SVHS. The details regarding the TV standards themselves are
\napplicable to all recording formats.<\/p>\n
THE WORLD’S TV STANDARDS<\/p>\n
The color television system in use in the United States was adopted in
\n1953, and because the United States was the first to widely implement color
\ntelevision, we have the oldest (though not necessarily the best) color
\ntelevision standard in the world. Considering the era in which it was
\ndevised, the system represents nothing short of genius on the part of its
\ndesigners. Our TV system acted as the progenitor of all of the other TV
\nbroadcast systems to come.<\/p>\n
Our TV system is referred to as “NTSC” (National Television System
\nCommittee), and is used only in the U.S., Canada, Mexico, Central America,
\nthe UAE, Burma, the Pacific coastal countries in South America, and in
\nparts of the Far East. When implemented, it represented a comprised effort
\nto transmit color video within a comparatively narrow bandwidth allocation,
\nwhile it maintained compatibility with the 100,000 or so black-and-white
\ntelevisions that had already been sold in the U.S.<\/p>\n
The European countries began broadcasting color television in the late 50’s
\nand early 60’s, and having had the dual advantages of time to improve on
\nour system, and wider channel bandwidth assignments; adopted either the PAL
\n(Phase Alternating Line) or SECAM (the French acronym for Sequential Color
\nwith Memory) color TV systems. Both the PAL and SECAM systems were
\nintended to alleviated some inherent weaknesses in the early vacuum tube
\nbased NTSC equipment, although today their greatest advantage over NTSC
\nstems from their wider bandwidth allocations. With the narrower channel
\nbandwidths used in the U.S., it would be impossible for us to “switch” to
\neither the European PAL or SECAM systems.<\/p>\n
Besides PAL and SECAM, there also exist two additional color TV standards:
\nPAL-M, which is used only in Brazil; and PAL-N, which is used in Argentina,
\nParaguay, and Uruguay. PAL-M is a “hybrid” of both the NTSC and European
\nPAL systems. It is an attempt to “fit” the PAL system within the same
\nfrequency spectrum that is used by NTSC. PAL-M uses the same
\nspecifications as NTSC for the black-and-white portion of the program
\n(referred to in TV parlance as the “luminance” information), but it uses a
\nmodified form of the PAL system for its color (or “chrominance”)
\ninformation. Thus, NTSC and Brazilian PAL-M VHS recordings are
\ninterchangeable — but only for black-and-white playback. While some PAL-M
\nVHS machines are capable of playing NTSC, PAL-M televisions cannot
\nreproduce the color portion of an NTSC program without using a special
\ndevice known as a “transcoder.” A transcoder takes the video program and
\nreduces it to its color components – much like a television receiver does –
\nand then reassembles these components in the new TV standard. Transcoding
\nis a far simpler process than standards conversion, but it can only be used
\nwhen the black-and-white standards of the two TV systems are the same.<\/p>\n
PAL-N on the other hand, uses the same black-and-white system as PAL and
\nSECAM, but with a slightly modified PAL system for conveying the color
\ninformation within a narrower RF bandwidth. PAL-N can be transcoded to or
\nfrom either PAL or SECAM.<\/p>\n
TV STANDARDS CONVERSION<\/p>\n
The process of TV standards conversion involves accurately converting video
\ninformation to a receiving rate that is different than the rate at which it
\nis being transmitted. In NTSC, 30 (actually 29.97) “frames,” or individual
\npictures, are transmitted each second. These frames are very similar from
\na conceptual standpoint to the individual frames in a motion picture. Also
\nin NTSC, each frame is made up of 525 individual scan lines. PAL on the
\nother hand has only 25 frames per second (5 fewer per second than NTSC),
\nand has 625 lines per frame (100 more than NTSC).<\/p>\n
The world today has fortunately settled on only two line and frame
\n rate standards:<\/p>\n
NTSC & PAL-M use 30 frames per second and 525 lines per frame.
\n PAL, PAL-N, & SECAM use 25 frames per second and 625 lines per frame.<\/p>\n
A standards conversion from NTSC to PAL involves discarding 5 frames per
\nsecond, while literally inventing 100 lines per frame. If the extra frames
\nwere simply thrown away, the resulting video would be so full of jerks and
\njumps that it would be unviewable, so a good standards converter will
\n“interpolate” or average the information from one frame to the next. The
\nstandards converter does this by storing one or more frames in an
\nelectronic memory and then performing a comparison between the stored
\nframes. The more memory — the more accurate is this averaging process.
\nThe extra lines are either invented or discarded by a similar averaging
\nsystem. The inner workings of modern TV standards converters are actually
\nmuch more complex than described above: a modern converter uses high speed
\nreal-time computing techniques to detect and differentiate between moving
\nand stationary objects in every frame of every scene in order to further
\nreduce the appearance of jerkiness in the converted video.<\/p>\n
TV STANDARDS IN USE<\/p>\n
The following is a list of TV broadcast standards in use. This information
\nis based on the XVIth Plenary Assembly of the Consultative Committee
\nInternational Radio (CCIR), Dubrovnik, 1986.<\/p>\n
NTSC COUNTRIES:<\/p>\n
Bermudas
\n Bolivia
\n British Virgin Islands
\n Burma<\/p>\n
Canada
\n Chile
\n Colombia
\n Costa Rica
\n Cuba<\/p>\n
Dominican Republic<\/p>\n
Ecuador<\/p>\n
Guatemala<\/p>\n
Haiti
\n Honduras<\/p>\n
Jamaica
\n Japan<\/p>\n
Korea (South)<\/p>\n
Mexico
\n Montserrat<\/p>\n
Netherland Antilles
\n Nicaragua<\/p>\n
Panama
\n Peru
\n Philippines<\/p>\n
Saint Christ. and Nevis
\n Surinam<\/p>\n
United Arab Emirates
\n United States<\/p>\n
Venezuela<\/p>\n
PAL COUNTRIES:
\n *PAL-N Standard **PAL-M Standard<\/p>\n
Albania
\n Algeria
\n Angola
\n Argentina*
\n Australia<\/p>\n
Bahrain
\n Bangladesh
\n Belgium
\n Botswana
\n Brazil**
\n Brunei<\/p>\n
Cameroon
\n China (People’s Republic)<\/p>\n
Denmark,
\n with Greenland and Faroes<\/p>\n
Equatorial Guinea
\n Ethiopia<\/p>\n
Finland<\/p>\n
Germany (Unified) (SECAM is currently being
\n simulcast in what was formerly “East”
\n Germany)
\n Ghana
\n Gibraltar
\n Great Britain (England, Scotland, & Wales)<\/p>\n
Hong kong<\/p>\n
Iceland
\n India
\n Indonesia
\n Ireland (Northern & Rep. of)
\n Israel
\n Italy<\/p>\n
Jordan<\/p>\n
Kenya
\n Korea (North)
\n Kuwait<\/p>\n
Lesotho
\n Liberia
\n Luxembourg<\/p>\n
Malawi
\n Malaysia
\n Maldives
\n Malta
\n Monaco
\n Mozambique<\/p>\n
Netherlands
\n New Guinea
\n New Zealand
\n Nigeria
\n Norway<\/p>\n
Oman<\/p>\n
Pakistan
\n Paraguay*
\n Portugal<\/p>\n
Qatar<\/p>\n
Romania<\/p>\n
Sierra Leone
\n Singapore
\n South Africa
\n Spain
\n Sri Lanka
\n Sudan
\n Sweden
\n Switzerland
\n Syria<\/p>\n
Tanzania
\n Thailand
\n Tunisia
\n Turkey
\n Uganda
\n Uruguay*<\/p>\n
Yemen (North & South)
\n Yugoslavia<\/p>\n
Zambia
\n Zimbabwe<\/p>\n
SECAM COUNTRIES:
\n (Note: Except for France, either the MESECAM or PAL systems are the
\n preferred standards for VHS interchange – refer to text below)<\/p>\n
Afghanistan<\/p>\n
Benin
\n Bulgaria
\n Burkina Faso
\n Burundi<\/p>\n
Central African Rep.
\n Chad
\n Congo
\n Cyprus
\n Czechoslovakia<\/p>\n
Djibouti<\/p>\n
Egypt<\/p>\n
France<\/p>\n
Gabon
\n Greece
\n Guinea<\/p>\n
Hungary<\/p>\n
Iran
\n Iraq
\n Ivory Coast<\/p>\n
Lebanon
\n Libya<\/p>\n
Madagascar
\n Mali
\n Mauritania
\n Mongolia
\n Morocco<\/p>\n
Niger<\/p>\n
Poland<\/p>\n
Rwanda<\/p>\n
Saudi Arabia
\n Senegal<\/p>\n
Togo<\/p>\n
USSR<\/p>\n
Vietnam<\/p>\n
Zaire<\/p>\n
Occasionally you may encounter suffix letters after the TV standard
\nspecification, i.e., “PAL-B, PAL-I, SECAM D\/K”, etc. These suffixes refer
\nto internationally agreed upon TRANSMISSION standards (promulgated by the
\nCCIR), and are important only for TV receivers\/tuners and transmitters\/RF
\nconverters. Except for the two unusual standards of PAL-M and PAL-N, which
\nare separate TV systems in their own right, these terms are irrelevant for
\nthe exchange of PRERECORDED VHS cassettes.<\/p>\n
Finally, there are two methods of recording SECAM on VHS. The first method
\ncomplies with the accepted JVC “standard” for SECAM recording and is
\ngenerally referred to as either the “Standard” or “French” SECAM method.
\n(Because of the prevalence of Standard SECAM machines in France, the
\nStandard SECAM recording method is often referred to as “French SECAM.”)
\nThe second, and most common method, is referred to as “MESECAM,” or Middle
\nEast SECAM. The “Middle East SECAM” method derives its name from the fact
\nthat the Middle East has a checkerboard of PAL and SECAM broadcast
\nservices. MESECAM was developed to allow a PAL VHS machine to record both
\nPAL and SECAM broadcasts with only a very slight modification of the PAL
\ncircuitry. Unfortunately, not only is MESECAM video quality inferior to
\n“Standard” SECAM VHS, but the method of recording SECAM video on the tape
\nitself makes the recording incompatible with a “Standard” or “French” SECAM
\nVHS machine — SECAM recordings that are interchanged between MESECAM and
\nStandard SECAM VHS machines will play back in black-and-white only. (For
\nthose who are interested in the technical reason for this incompatibility:
\nMESECAM uses a heterodyne method for deriving the color-under subcarrier —
\nthe same method that is used for PAL and NTSC VHS, whereas Standard SECAM
\ndigitally divides the two SECAM FM chrominance subcarriers by 4. If the
\nwrong reverse-process is used on playback, it results in the SECAM
\nsubcarriers being at the wrong frequencies, and the sidebands being too
\nwide or too narrow.)<\/p>\n
With the exception of France, MESECAM is by far the most common VHS system
\nused in SECAM broadcast countries. This is partly a matter of
\nsupply\/demand economics, and partly because many of the countries that are
\nbroadcasting SECAM have had closed socialist economies in the past. As a
\nresult of these closed systems, most of the video software that has been
\nobtainable has had to be smuggled in from the West — and was recorded in
\nPAL. Everyone who has a MESECAM VHS machine also has the ability to play
\nPAL recordings, and with the addition of a simple transcoder, a SECAM TV
\nreceiver can display PAL recordings in color. If the intended recipient of
\na VHS cassette has the ability to play PAL recordings I suggest that you
\nsend recordings in PAL rather than MESECAM due to the differences in
\nrecording quality.<\/p>\n
BLANK VHS CASSETTES<\/p>\n
As described above, there are 5 color television standards in use
\nthroughout the world, and 6 ways of recording video on VHS. Without
\n“standards conversion,” the only foreign standard that can be played at all
\non an American VHS machine is PAL-M (the Brazilian standard), and then only
\nin black-and-white.<\/p>\n
Fortunately, the situation is far less complicated with regard to BLANK VHS
\ncassettes. VHS cassettes are mechanically identical in all TV standards.
\nThe only difference is that the tape SPEED is higher in NTSC (and PAL-M),
\nand therefore, the recording time in NTSC is shorter for a given amount of
\ntape.<\/p>\n
NTSC consumes tape at a rate of 2.0 meters per minute in standard play (SP)
\nmode, and both PAL and SECAM consume tape at a rate of 1.42 meters per
\nminute. Although it isn’t necessary to take blank VHS cassettes along with
\nyou on a trip to Europe, you will need to do a little math to determine the
\nrecording time allowed on a blank European VHS cassette. The tape
\nmanufacturers generally make this easier for you by showing both the length
\n(in meters) of the blank tape, and by designating the labelled European or
\nAmerican length with a code letter. American (NTSC) blank cassettes are
\nmarked with the letter “T” preceding the length, e.g., T-120; and European
\nPAL\/SECAM cassettes are marked with the letter “E” before the length, e.g.,
\nE-180.<\/p>\n
An E-180 (180 minutes in PAL\/SECAM) cassette will contain approximately 258
\nmeters of blank tape, and on this blank tape you can record: 258 divided by
\n2 minutes of NTSC video; or 129 minutes of NTSC program.<\/p>\n
The following is a conversion table of tape lengths and recording times:<\/p>\n
Length code Blank tape length * NTSC\/PAL-M time PAL\/PAL-N\/SECAM time
\n———– —————– ————— ——————–<\/p>\n
T-20 44 meters 20 minutes 28 minutes
\n T-30 64 meters 30 minutes 42 minutes
\n T-40 84 meters 40 minutes 56 minutes
\n T-45 94 meters 45 minutes 63 minutes
\n T-60 125 meters 60 minutes 84 minutes
\n T-80 165 meters 80 minutes 112 minutes
\n T-90 185 meters 90 minutes 126 minutes
\n T-120 246 meters 120 minutes 169 minutes
\n T-130 266 meters 130 minutes 183 minutes
\n T-160 326 meters 160 Minutes 225 minutes<\/p>\n
E-30 45 meters 22 minutes 30 minutes
\n E-60 88 meters 44 minutes 60 minutes
\n E-90 130 meters 65 minutes 90 minutes
\n E-120 173 meters 86 minutes 120 minutes
\n E-150 215 meters 107 minutes 150 minutes
\n E-180 258 meters 129 minutes 180 minutes
\n E-240 346 meters 173 minutes 240 minutes<\/p>\n
* Most tape manufactures add 3 to 6 meters of blank tape to their cassettes
\nto allow for tape threading in the mechanism and for recording speed
\ninaccuracies.<\/p>\n
EXCHANGING VHS RECORDINGS BETWEEN TV STANDARDS:<\/p>\n
There are only four possible methods of viewing a VHS recording in a
\nforeign TV standard:<\/p>\n
1) purchase a multistandard converting VCR (such as the Panasonic AG-W1),
\n2) purchase a VCR and television (and usually a voltage conversion
\ntransformer) designed for the foreign standard,
\n3) “transcode” the video to the viewer’s TV standard or,
\n4) have the tape standards converted to the viewer’s “home” television
\nstandard.<\/p>\n
If the exchange is between NTSC and PAL or SECAM countries, the first two
\noptions will involve an expense of around $2,000. The third option,
\ntranscoding, is inexpensive and quite popular in Eastern Europe where
\nthere are very few pre-recorded movies available in SECAM. (In fact, in a
\nrecent survey of Leningrad, USSR – a SECAM country – I was unable to find
\nany SECAM recordings at the video rental shops – all of their recordings
\nwere in PAL. The Soviet Union now manufactures color televisions that
\neliminate the need for a transcoder by automatically detecting and
\ntranscoding PAL programs, such as the “Raduga” or “Rainbow” TV receiver
\nmanufactured by Elektornika in Leningrad.) Unfortunately, the transcoding
\nmethod can only be used when converting video between two TV standards that
\nhave the same line and frame rate standards (the same black-and-white
\nsystem). Transcoding is not an option when converting between PAL or SECAM
\nand NTSC. The fourth option, standards conversion, is an economically
\nappropriate method for an occasional exchange of video programs between
\nNTSC and PAL\/SECAM countries. Standards conversion of a VHS cassette will
\ncost approximately $20 per hour of program, and this service can be
\nprovided usually with a 4 or 5 day turn-around to any location in the U.S.
\nby firms such as Video Bridge (telephone: 800-877-4015).<\/p>\n
When having a VHS cassette standards converted, it is important to make
\nsure that a digital process is being used for the conversion. The results
\nof the older analog standards converters are inferior in all respects, and
\nmost laboratories today use digital “8 bit\/2 field” – and more recently –
\n“8 bit\/4 field” systems. The biggest difference between the 2 field and 4
\nfield systems is in the accuracy of their motion interpolation. With the
\nolder 2 field systems, moving objects in the video, particularly background
\nscenes during a camera pan, will occasionally appear to jump from point-to-
\npoint rather than moving smoothly. Although the video output from a 4
\nfield converter still represents something of a compromise, moving objects
\nappear much more natural. (Since the typical cost of an 8 bit\/4 field
\nconverter is $90,000, some laboratories have yet to upgrade their
\nequipment.) The most rudimentary method of standards conversion involves
\nliterally pointing a TV camera of one standard at a TV display of another
\nstandard. This method produces results that are absolutely unacceptable to
\nmost viewers today.<\/p>\n
If you are sending a converted VHS cassette to Europe, it is also important
\nto determine if the conversion service is recording audio using the Hi-Fi
\n(sometimes called “HD”) FM recording system. Hi-Fi audio capability is far
\nmore common in Europe than in the U.S., and some conversion services here
\nin the U.S. try to skimp on this point.<\/p>\n
TV standards conversion today costs only a fraction of what it cost just a
\nfew years ago, and with the power of real-time computing performing motion
\ndetection, time-base correction, interpolation, noise reduction and image
\nenhancement; the quality of converted video has improved to the point that
\nthe conversion process has not only become essentially transparent, but
\noften the converted copies are superior to the original. In fact, most of
\nthe international programming that we see today was converted using the
\nsame technology that will be applied to your videos. If you intend to
\nexchange video programs with someone living abroad, you can do so today by
\nusing any of the quality standards conversion services.<\/p>\n
The following glossary of terms is intended to assist you
\nwith the specialized terminology used in international
\ntelevision standards.<\/p>\n
Glossary:
\n Glossary:<\/p>\n
Legend: The following designations have been used to avoid
\n confusion, and to separate the definitions of terms
\n that have multiple meanings:<\/p>\n
(Video): Applies to a video standard.<\/p>\n
(VHS): Applies to the method of recording or
\n reproducing video with a VHS machine.<\/p>\n
(RF): Applies to radio frequency spectrum
\n allocations, usually embodied in
\n international treaties. Used to
\n describe the design of television
\n transmitters, receivers, and tuners.<\/p>\n
(Receivers): Applies to terms used to describe the
\n design of television receivers.<\/p>\n
CCIR (Video) The French acronym for International Radio
\n Consultative Committee. The CCIR has
\n established recommendations for the video and
\n transmission characteristics of all of the
\n world’s television systems. The term “CCIR
\n video” is often encountered and is
\n meaningless unless the television video
\n standard to which this term applies is
\n further specified. As a colloquialism, the
\n term “CCIR video” is most frequently
\n used in reference to the monochrome
\n standards of 625 lines per frame and 50
\n fields per second; as well as the voltages,
\n aspect ratios, gammas, etc., that both PAL
\n and SECAM have in common. Since both PAL
\n and SECAM are the same monochrome video
\n standard, what is usually meant by this
\n colloquial usage is simply; “black-and-white
\n PAL\/SECAM.” “CCIR video” is often touted by
\n VHS manufacturers as if it were a separate
\n video or VHS standard. The term “CCIR video”
\n has been used erroneously by at least one VHS
\n manufacturer in reference to MESECAM (VHS).<\/p>\n
EIA (Video) Electronic Industries Association. Often
\n used to refer to the original monochrome
\n standard from which NTSC was later
\n developed, i.e., 525 lines per frame and 60
\n fields per second. The term “EIA video” is
\n sometimes used to refer to “NTSC without
\n color information.” “EIA video” is often
\n touted by VHS manufacturers a separate video
\n standard, when in fact it is merely black-
\n and-white NTSC.<\/p>\n
THE NTSC SYSTEMS:<\/p>\n
EIA 4.43 MHz A colloquial misnomer. See N443 (Video\/VHS).
\n (Video\/VHS)<\/p>\n
N443, or An unofficial television video standard.
\n NTSC 4.43 With NTSC 4.43 (or N443), a recording is made
\n (Video\/VHS) in normal NTSC. The recorded tape may then
\n be viewed on a compatible PAL monitor that is
\n capable of “locking” its deflection circuitry
\n onto the NTSC line and field rates. During
\n playback, the down-converted chrominance
\n sidebands that are centered around 629 kHz
\n on the tape, are up-converted to be centered
\n around 4.43 MHz. Since the video was recorded
\n with the NTSC color system, a compatible PAL
\n monitor will detect a 59.94 Hz field rate
\n (NTSC) and will disable its PAL “switching”
\n circuitry and thus reproduce color NTSC
\n pictures (but without the advantages of the
\n PAL color “system,” i.e., the phase of the R-
\n Y component will not be reversed on alternate
\n lines). This allows the playing of NTSC tapes
\n in PAL countries on compatible tape machines,
\n without the use of an expensive standards
\n converter. Unfortunately, comparatively few
\n multistandard VHS machines and monitors
\n exist. Therefore, this “standard” is of
\n little significance for exchanging VHS programs.<\/p>\n
NTSC 3.58 Ordinary NTSC color video. This term is used
\n (Video\/VHS) on some multistandard VHS machines and
\n receivers\/monitors to distinguish normal NTSC
\n from the NTSC 4.43 “standard.”<\/p>\n
NTSC National Television System Committee. The
\n (Video\/VHS) color television video standard used
\n throughout North America, in much of
\n Central and South America, and in much of
\n East Asia. Implemented in 1953, it was the
\n first form of monochrome-compatible color
\n television, and uses a slightly modified
\n version of the original 525 lines per
\n frame\/60 fields per second monochrome system.
\n NTSC employs suppressed-carrier
\n quadrature amplitude modulation for
\n transmitting two color difference signals
\n (I and Q) on a 3.58 MHz suppressed
\n subcarrier. There is no interchangeability
\n of recorded material between non-
\n multistandard PAL-N\/PAL\/SECAM (625 line\/50
\n field) and NTSC\/PAL-M (525 line\/60 field) VHS
\n machines. NTSC may be transcoded to PAL-M.<\/p>\n
SuperNTSC * A proprietary NTSC-compatible “line doubling”
\n (Receivers\/ technique developed by Faroudja Laboratories
\n Video) that provides enhanced definition video.
\n Although full implementation of the system
\n requires a decoder and line-doubler at the
\n receiver end, receivers without decoders are
\n claimed to benefit from the removal of NTSC
\n “artifacts.”<\/p>\n
M\/NTSC (RF) Also called NTSC-M. The “M” designation is
\n of no interest in VHS duplication. M\/NTSC is
\n the transmission\/video standard that is used
\n in the United States and in all other NTSC
\n countries except Jamaica.<\/p>\n
THE PAL SYSTEMS:<\/p>\n
PAL Phase Alternating Line. An improvement of
\n (Video\/VHS) NTSC video. Since PAL was implemented
\n mostly in countries using 50 hertz mains
\n supply power and the early scanners (Nipkow
\n disc, Weiller wheel, and film scanners) made
\n use of AC supplied synchronous motors, a
\n field frequency of 50 fields per second was
\n chosen. PAL uses 625 lines per frame. In
\n the PAL video standard, the phase of the R-Y
\n (or “V”) component is reversed on alternate
\n lines, and thus any phase distortion that
\n occurs in transmission can be “averaged out”
\n at the receiver by use of a delay line.
\n Unlike NTSC, in the PAL system differential
\n phase errors do not appear as objectionable
\n hue errors in the displayed video (the colors
\n become desaturated instead). The PAL system
\n does not eliminate the distortions in color
\n saturation that are caused by either
\n differential gain errors or as a by-product
\n of differential phase errors. Like NTSC, PAL
\n employs a similar method of suppressed-
\n carrier quadrature amplitude modulation for
\n transmitting two color difference signals
\n (designated “U” and “V”); but on a subcarrier
\n frequency of 4.43 MHz. There is no
\n interchangeability of recorded material
\n between non-multistandard PAL and NTSC VHS
\n machines. PAL VHS recordings are
\n interchangeable with SECAM (VHS) and MESECAM
\n (VHS), but only for monochrome playback. PAL
\n can be transcoded to SECAM and PAL-N.<\/p>\n
PAL B Refers to the modern form of the PAL video
\n standard. This term is rarely encountered.
\n This term should not be confused with PAL
\n video that is transmitted within the
\n bandwidth limits and on the channel spacings
\n that carry a CCIR “B” designation {see also
\n B\/PAL (RF)}.<\/p>\n
PAL D PAL Deluxe. Referred to occasionally as
\n (Receivers) “D.L. PAL.” This is a receiver\/monitor
\n specification, and the term has no
\n application to VHS or to the PAL video
\n standard. In PAL D, a delay line is used in
\n the receiver or monitor to average the
\n chrominance on alternating lines. Many
\n studio monitors allow this delay line to be
\n switched off, yielding “simple PAL.” Due to
\n the averaging of the chrominance information,
\n use of a delay line results in an inherent
\n reduction in vertical chrominance resolution,
\n but alleviates an effect in PAL known as
\n “Hanover bars,” which occur in the presence
\n of moderate differential phase distortion.
\n This term should not be confused with PAL
\n video that is transmitted within the
\n bandwidth limits and on the channel spacings
\n that carry a CCIR “D” designation {see also
\n D\/PAL (RF)}.<\/p>\n
Simple PAL See PAL D (Receivers).
\n (Receivers)<\/p>\n
PAL-M A television video standard used only
\n (Video\/VHS\/RF) in Brazil. PAL-M uses the same 525 line 60
\n field system as NTSC for monochrome video
\n (RF bandwidth, field\/line rates, gamma,
\n etc.), but it uses the PAL system (with a
\n modified subcarrier frequency) for its color
\n information. Since PAL-M has the same line
\n and field rates as NTSC, PAL-M can be
\n transcoded to and from NTSC.<\/p>\n
PAL-N A television video standard used principally
\n (Video\/RF) in Argentina. PAL-N uses the same color
\n system and line\/field rates as PAL, but with
\n a lower subcarrier frequency to accommodate
\n restricted RF bandwidth allocations for
\n broadcasting. Most PAL-N VHS machines are capable
\n of playing (standard) PAL recordings. PAL-N
\n can be transcoded to PAL and SECAM.<\/p>\n
B\/PAL (RF) A transmission standard that specifies
\n channel spacings and bandwidths for
\n transmitters and tuners. Does not relate
\n directly to VHS recordings. The “B”
\n designation is of no interest in VHS
\n duplication. B\/PAL channel assignments are
\n used by the majority of PAL countries, with
\n the notable exception of the United Kingdom.<\/p>\n
D,G,H,\/PAL A transmission standard that specifies
\n (RF) channel spacings and bandwidths for
\n transmitters and tuners. Does not relate
\n directly to VHS recordings. The “D,G,or H”
\n designation is of no interest in VHS
\n duplication. The CCIR designation “D\/PAL”
\n should not be confused with the PAL D receiver
\n specification {see also PAL D (Receivers)}.<\/p>\n
I\/PAL (RF) A transmission standard that specifies
\n channel spacings and bandwidths for
\n transmitters and tuners. Does not relate
\n directly to VHS recordings. The “I”
\n designation is of no interest in VHS
\n duplication.
\n THE SECAM SYSTEMS:<\/p>\n
SECAM (Video) Sequence Couleur a Memoire, or Sequential
\n Color with Memory. A monochrome-compatible
\n color television video standard proposed in
\n 1959\/1960, and intended to reduce the
\n problems of crosstalk between the two color
\n difference signals and the problems of
\n differential gain that are inherent in both
\n the PAL and NTSC video standards. SECAM
\n circumvents these problems by using two FM
\n carriers to convey the color information.
\n SECAM uses the same set of specifications as
\n PAL for its luminance information, and is
\n therefore the same monochrome video standard
\n as PAL. SECAM differs from PAL only in the
\n way that its chrominance information is
\n conveyed. The CCIR recommends a single
\n standard for SECAM video, and only slight and
\n generally irrelevant dissimilarities exist in
\n SECAM video in the countries in which it is
\n used; the most notable difference being the
\n deletion of vertical-interval “bottles” in
\n some countries {see SECAM Bottles (Video)}.
\n There are two incompatible methods of recording
\n SECAM on VHS {see also SECAM (VHS) and MESECAM
\n (VHS)}. SECAM can be transcoded to PAL and PAL-N.<\/p>\n
SECAM Bottles The subject of SECAM “bottles” has been the
\n (Video) source of considerable confusion with regard
\n to VHS duplication. The failure of color
\n playback of SECAM VHS recordings has often
\n been blamed on the absence or presence of
\n recorded “bottles” in the SECAM video; when
\n in fact the compatibility problems are usually
\n the result of an interchange of tapes between
\n Standard or “French” SECAM and MESECAM
\n machines. The inclusion or deletion of
\n “bottles” in recorded SECAM video is not a
\n compatibility issue with regard to the
\n operation of VHS machines; since SECAM and
\n MESECAM VHS machines never demodulate the
\n SECAM chrominance information, and therefore
\n never make any use of the “bottles.” Both
\n SECAM and MESECAM VHS machines will record
\n and play back SECAM “bottles.” With regard
\n to VHS duplication, the need for recorded
\n “bottles” is dictated only by the design of
\n the viewers’ television receivers. Most SECAM
\n countries, including France, have dropped the
\n requirement for vertical interval “bottles”
\n in their broadcast video {CCIR report 624-3}.
\n Unless a conflict exists that requires the
\n use of the horizontal lines that are normally
\n occupied by the “bottles” for recording<\/p>\n
information such as teletext or other
\n vertical interval signals on VHS; including
\n the “bottles” signal in VHS duplicates will
\n do absolutely no harm and will assure
\n compatibility with the few receivers that make
\n use of this signal.<\/p>\n
SECAM (VHS) Also called “French SECAM” or “Standard
\n SECAM.” Only relates to VHS recordings.
\n A method of producing the color-under
\n chrominance information for recording and
\n playing back SECAM video on VHS by dividing
\n the two SECAM FM chrominance subcarriers by 4
\n during recording, and multiplying these
\n subcarriers by 4 during playback. Because
\n this method uses a completely different
\n scheme than that used in PAL VHS machines for
\n recording the chrominance information, this
\n method of recording SECAM video is most
\n commonly found on single-standard SECAM-only
\n VHS machines. Because of the availability of
\n pre-recorded VHS program material in France,
\n the consumer-base in France has not been
\n forced to resort to using PAL VHS machines to
\n view pre-recorded programs. Therefore,
\n SECAM-only (standard) VHS machines are
\n predominant in France. This is the basis for
\n the term “French SECAM” when used in
\n reference to VHS recording methods. Although
\n both SECAM (VHS) and MESECAM (VHS) machines
\n will record and play back SECAM color video,
\n there is no interchangeability of recorded
\n material for color playback between MESECAM
\n (VHS) and SECAM (VHS) machines. Color video
\n recordings that are interchanged between
\n MESECAM (VHS) and SECAM (VHS) machines will
\n play back in monochrome. PAL VHS recordings
\n are interchangeable with SECAM (VHS)
\n machines, but also for monochrome-only
\n playback. {See also MESECAM (VHS), SECAM
\n Bottles (Video)}.<\/p>\n
SECAM-East See MESECAM (VHS). Relates only to VHS
\n (VHS) recordings.<\/p>\n
French SECAM A colloquialism. This term is generally used
\n (Video\/VHS) in the vernacular only in reference to VHS;
\n and in this instance, see SECAM (VHS). When
\n used in reference to receivers and tuners,
\n see L\/SECAM (RF). When used in reference to
\n video, see SECAM (Video). “French SECAM” is
\n often referred to incorrectly as if it were
\n a completely unique video or VHS standard.
\n SECAM in France is unique only in the way in
\n which it is broadcast {see L\/SECAM (RF)}.
\n The confusion regarding the term “French
\n SECAM” is exacerbated by the fact that France
\n uses a unique method for broadcasting both
\n video and audio; and thus, the tuners and RF
\n modulators in French VHS machines must follow
\n a slightly different design. However, the
\n SECAM video signals that are applied to
\n transmitters in France, and the demodulated
\n video that is produced by VHS machines in
\n France; conform to the single CCIR standard
\n that is used in all SECAM countries.<\/p>\n
MESECAM (VHS) Middle-East SECAM. Also called “SECAM-East”
\n or “Pseudo SECAM.” “MESECAM” relates only VHS
\n recordings, and does not relate to the SECAM
\n video standard itself. MESECAM derives its
\n name from the fact that the Middle-East has
\n many overlapping areas of both PAL and SECAM
\n broadcast coverage. MESECAM provides an
\n economical method of using the PAL circuitry
\n in a PAL\/MESECAM VHS machine for recording
\n and playing back SECAM video. These machines
\n accomplish this by using the same
\n mixer\/heterodyne circuitry that is used for
\n recording and playing back PAL video. This
\n method requires only slight modification of a
\n PAL recorder\/reproducer, and thus it is the
\n most common and economical method of
\n recording and playing back both SECAM and PAL
\n video on these dual standard VHS machines.
\n Although both (standard or “French”) SECAM
\n (VHS) and MESECAM (VHS) machines will record
\n and play back SECAM video in color, there is
\n no color interchangeability of recorded tapes
\n between standard SECAM VHS and MESECAM VHS
\n machines. The video quality of MESECAM (VHS)
\n is generally inferior to that of SECAM (VHS).
\n In countries where MESECAM (VHS) predominates
\n (such as in the USSR), you should
\n consider duplicating in PAL (VHS) since all
\n MESECAM (VHS) machines possess PAL playback
\n capability. {See also SECAM (VHS), SECAM
\n “Bottles”}.<\/p>\n
Pseudo SECAM See MESECAM (VHS). Relates only to VHS
\n (VHS) recordings.<\/p>\n
B,G\/SECAM A transmission standard that specifies
\n (RF) channel spacings and bandwidths for
\n transmitters and tuners. Does not relate
\n directly to VHS recordings. The “B,G”
\n designation is of no interest in VHS
\n duplication. B,G SECAM transmission
\n assignments have been assigned to countries
\n in the Middle-East, Northern Africa, and at
\n the time of this writing to “East” Germany.
\n ME-SECAM (VHS) is predominate in these markets.<\/p>\n
D,K\/SECAM A transmission standard that specifies
\n (RF) channel spacings and bandwidths for
\n transmitters and tuners. Does not relate
\n directly to VHS recordings. The “D,K”
\n designation is of no interest in VHS
\n duplication. D,K\/SECAM relates only to
\n spectrum and channel assignments for
\n broadcasting. D,K\/SECAM is used in
\n Bulgaria, Czechoslovakia, Hungary, Poland,
\n and the USSR. A SECAM television
\n receiver purchased in Poland, for example,
\n will not receive television broadcasts in
\n France — although the SECAM video in
\n both countries is exactly the same.
\n ME-SECAM (VHS) is predominate in these markets.<\/p>\n
H,K1\/SECAM A transmission standard that specifies
\n (RF) channel spacings and bandwidths for
\n transmitters and tuners. Does not relate
\n directly to VHS recordings. The “H or K1”
\n designation is of no interest in VHS duplication.
\n ME-SECAM (VHS) is predominate in these markets.<\/p>\n
L\/SECAM (RF) A transmission standard that specifies
\n channel spacings, visual modulation polarity,
\n and bandwidths for transmitters and tuners.
\n The “L” designation is of no interest in VHS
\n duplication. L\/SECAM is used in France.
\n L\/SECAM is unique in the way that it is
\n transmitted. Although the video is the same
\n as in all other SECAM countries, L\/SECAM is
\n transmitted with the opposite video RF
\n modulation polarity (positive) from all other
\n systems, and the audio is transmitted using
\n AM rather than FM modulation. You
\n should use standard (frequency division) SECAM
\n VHS for this market.<\/p>\n
Russian SECAM A colloquialism. Used in the vernacular only
\n (VHS) in reference to VHS. See MESECAM (VHS). (The
\n SECAM video that is broadcast in the USSR is
\n not unique and conforms to the single CCIR
\n standard.)<\/p>\n
SECAM I,II, Early phases of development of the television
\n or III video standard that is now known simply as
\n (Video) “SECAM.” Since the final form of modern
\n “SECAM” resulted from the optimization of the
\n model called “SECAM III,” modern SECAM will
\n still occasionally be referred to as “SECAM
\n III.”<\/p>\n
SECAM IV A variant of early SECAM that was never
\n (Video) considered or implemented.<\/p>\n
Soviet SECAM A colloquialism. Used in the vernacular only
\n (VHS) in reference to VHS. See MESECAM (VHS). (The
\n SECAM video that is broadcast in the USSR is
\n not unique and conforms to the single CCIR
\n standard.)<\/p>\n
Standard See SECAM (VHS).
\n SECAM (VHS)<\/p>\n
VHS Video Home System. Developed by Japan Victor
\n Company (JVC). A 1\/2 inch helical scan video
\n cassette format where the luminance
\n information is recorded by FM means, and the
\n chrominance sideband information is converted
\n by either heterodyne or frequency division
\n methods to a lower frequency for direct
\n recording.<\/p>\n
VHS SP VHS Standard Play. Refers to the linear
\n velocity of the video tape as it passes
\n through the transport. The “standard play”
\n speed for NTSC\/PAL-M (525 line standards) is
\n 33.35 millimeters per second, and for PAL\/
\n PAL-N\/SECAM\/ME-SECAM (625 line standards) is
\n 23.39 millimeters per second. Since the
\n amount of tape that is commonly loaded onto a
\n NTSC VHS cassette allows for 2 hours of recording
\n time in VHS SP mode, this speed is often
\n referred to as the “2 hour” mode.<\/p>\n
VHS LP VHS Long Play. Refers to the linear velocity
\n of the video tape as it passes through the
\n transport. The “long play” speed for NTSC
\n is 16.67 millimeters per second, and for PAL\/PAL-N
\n SECAM\/ME-SECAM is 11.69 millimeters per second.
\n VHS LP speed is one-half (50%) that of VHS SP
\n speed. VHS LP is not commonly found in NTSC
\n countries outside of North America. Since the
\n amount of tape that is commonly loaded onto a NTSC
\n VHS cassette allows for 2 hours of recording time
\n in VHS SP mode, this speed is often referred
\n to as the “4 hour” mode. Because the LP speed
\n in PAL\/SECAM is only slightly faster than EP
\n speed in NTSC, and because of the inherent
\n difficulties of recording in VHS PAL\/SECAM;
\n the quality of PAL\/SECAM VHS LP recordings is
\n generally unacceptable. You should
\n avoid the use of LP in PAL\/SECAM.<\/p>\n
VHS EP\/SLP VHS Extended Play. Also called “SLP” for
\n Super Long Play. “EP” or “SLP” speed
\n does not exist in PAL\/SECAM VHS.
\n The recording speed of VHS EP is one-third that
\n of the SP speed. Since the amount of tape that
\n is commonly loaded onto a NTSC VHS cassette allows
\n for 2 hours of recording time in VHS SP mode,
\n this speed is often referred to as the “6 hour”
\n mode.<\/p>\n
* SuperNTSC is a trademark of Faroudja Laboratories<\/p>\n
