Talk:SCART

Speculations about SCART introduction reasons

There's a whole section of speculations and claims about French legislation that are not supported by any references, which would normally be quite easy (legislation and regulations are indexed). David.Monniaux 08:52, 22 Apr 2004 (UTC)

Strangely, There is much truth in this (I note the reference has been removed). France has always had a particularly repressive government - extremely socialist verging on communist. The original French TV standard (the 819 line system) was introduced for two reasons. First: to prevent French citizens from watching unsuitable television broadcasts (i.e. anything not originating from the heavily government controlled French station). Second, to protect French television manufacturers from foreign competition as the 819 line system was a patented proprietary system.

When France moved to colour, it had to abandon the 819 line system as the bandwidth requirements were unacceptable. It was long speculated that the French SECAM colour system was to similarly discourage viewing of 'unsuitable material', but in fact the SECAM colour system was developed before the PAL system, used by the rest of Europe - and France hoped to sell it to the remainder of Europe. (Interestingly, the USSR adopted SECAM for precisely this reason.) France adopted the now European standard 625 line system, but adopted an inverted form of the system to prevent French televisions from receiving 'unsuitable broadcasts'. France used a system of positive video modulation, whereas the rest of the world had adopted negative modulation which was far less prone to breakup due to interference.

Hey! How do you know this is not just coffee machine ranting? Adam Mirowski 05:08, 22 October 2006 (UTC)[reply]

French analogue satellite broadcasts used a system called DMAC2 for much the same reason (though DMAC was actually a British development). With the introduction of Video Recording, the French developed the SCART interface and legislated that all French Televisions and Video recorders had to be fitted with the connector. The idea was to once again protect the French television and video industry from foreign competition as the connector was proprietary. Unfortunately for the French, the idea of having a single connector and cable to connect all the audio and video signals for recording and playback in one go was such a good one (even if the connector itself left a lot to be desired), that it was rapidly copied throughout Europe. So much so that the French were unable to launch patent infingement suits on the required scale.

Conspiracy theories forever! Adam Mirowski 05:08, 22 October 2006 (UTC)[reply]

Even today, the French are having to live with a digital TV system that is incompatible with the rest of Europe. The internet itself caused much panic in Paris, when the government heavily tried to discourage its use, and tried to pursuade French citizens to use the obsolete (but government controlled) Minitel system instead. I B Wright 16:10, 21 October 2006 (UTC)[reply]

Damn! You almost looked serious when I started reading this. Adam Mirowski 05:08, 22 October 2006 (UTC)[reply]

What is component video, really?

"RGB signals, which were SCART's strong point for many years, are getting less useful today, after the (arguably) superior component video signal format was introduced", I thought RGB was a type of component video ?

There are differing definitions of "component video". Some use it to mean "S-Video", i.e. luma and chroma separately, while others use a wider definition that includes RGB. I can't think of any reason for claiming that S-Video is "superior" to RGB, though. -- Heron 19:38, 10 May 2004 (UTC)[reply]

Ah. I have just done some reading, and I have found that another, and perhaps the correct, definition of "component video" is Y-Cb-Cr video (i.e. luma and the two quadrature components of chroma). This explains the statement "SCART cannot carry component video" in our article. I don't think this format is superior to RGB in terms of pure quality, but it makes more efficient use of bandwidth and is probably more than good enough for TV viewing. -- Heron (again)

YCbCr is not superior in any way. For all practical purposes, the two can be considered identical. The signal on a DVD or transmitted by digital television is YCrCb. The signal required by the display device, be it a CRT; Plasma or LCD display is RGB. The former has to be converted to the latter at some point in the chain and it does not matter whether this occurs in the DVD player or the digital TV set top box, or in the television set itself. To be really accurate, YCbCr has problems if it is to be carried over very long distances, because the CbCr components have a much narrower bandwidth than the Y component. Differing propagation coefficients of the signals will cause the colour information to arrive ahead of the luminance information. However, it does require a very long distance to make this effect noticeable. I B Wright 15:36, 21 October 2006 (UTC)[reply]

"Component video" by definition refers to any method of transmitting video signals in components, as opposed to composite video where it is all in the one line. Therefore, "component video" refers to either RGB, any forms of colour difference component (YUV, YPbPr, YCbCr, etc.) or S-Video. Saying it only refers to one of the above is incorrect, and just bad English. --Zilog Jones 18:31, 16 August 2005 (UTC)[reply]

Although you are correct, S-Video is not considered a component video system, because the chrominance wire does not carry a component, but rather the 2 colour difference signals quadrature modulated onto the suppressed colour sub-carrier just like CVBS (composite video). I B Wright 15:36, 21 October 2006 (UTC)[reply]

SCART should be innovated

SCART is a very good type of multipurpose audio/video cable but it has become rather large. Why don't they change the connector to something with smaller pins, closer to each other (ie the DVI pin layout). In addition with the new connector more pins could be added to carry more signals/cables. An adapter could also be created to still be able to plug the cable into a normal SCART connector. my 2 cents, Stef Nighthawk.

I've knocked off 'So it is difficult to argue with the no-import rationale above' from the end of the speculations bit because it's irrational. It essentially presents the second suggestion as a straw man.

Personally, I think that whole section is silly.

RESPONSE:

The pins are further apart to prevent cross-talk, and therefore increase picture quality. DVI/HDMI Cables have the pins closer together because Digital Cables are less prone to cross-talk and so picture quality does not suffer.

MORE: Quite a few set-top box manufacturers have elected to use smaller connectors, particularly on the back of digital STBs, where the mini-DIN has been used. This of-course requires a special lead to connect to the TV's standard SCART socket. Manufacturers I can think of who have gone for this approach include Amino Communications and Video Networks' HomeChoice boxes. A disadvantage of this aproach is that the thick cables needed for good-quality video and audio can put a lot of strain on such small connectors. I believe they have chosen different pin-outs, too. — Kim SJ 12:10, 22 August 2006 (UTC)[reply]

This, unfortunately, isn't a new obsession though; I have 1980's home entertainment gear that uses mini-DIN's which could either be used direct to connect to other gear by the same maker, or through nastily huge adapters for RCA or SCART. None of them seem to let you output RGB over them either. --Kiand 12:14, 22 August 2006 (UTC)[reply]

Not true

The article states that "In general, 5.1 sound is new to European TV, it only started to appear in 2004, on selected satellite channels."

This is not true, as for example some German TV Stations, ProSieben for example, started broadcasting Dolby Digital via Satellite, and I think Digital Cable (sic, satellite AND cable - another correction to the article), at least around 2002, maybe even earlier. thanks, --Abdull 20:16, 17 Jan 2005 (UTC)

And what about DVDs and LaserDiscs, which have had surround sound for many years? Things that aren't broadcasted can use SCART cables too! --193.1.100.105 10:37, 29 Mar 2005 (UTC)

I've removed that, as it was both incorrect and irrelevant - whether 5.1 is new or not, the lack of it is still a drawback. TerokNor 16:08, 26 Jun 2005 (UTC)

I would guess the person that wrote that was British, as 5.1 has only been available on TV in the UK since 2004 unless you were getting foreign satellite channels... *hugs his Comag*. --Kiand 21:24, 16 January 2006 (UTC)[reply]

IMHO there's a problem with the related drawback "SCART is limited to two audio channels - meaning it cannot deliver true surround sound", AFAIK it can deliver surround sound in matrixed forms (ie. ProLogic), which from my standpoint is as true as any other form. I believe true should be changed to discrete, but correct me if I'm wrong. --Outlyer 16:32, 3 July 2006 (UTC)[reply]

New pinout table

I propose a proper pinout table is added to this page. The list now is a bit hard to read, and confusing, as certain pins have different assignments whether the signal being transmitted is RGB, composite or s-video. Also, signal levels and impedance should be listed too. I suggest using this from pinouts.ru as a template for this - they don't seem to mention anything about copyrights or licenses, so I assume it's free imformation.

I have to find out how to do tables properly first, but I was thinking along the lines of this for the rows:

And another table for voltages/impedance for each pin. This is an important issue, especially with RGB as some devices output 1V RGB and others output .7V. --Zilog Jones 15:07, 1 Apr 2005 (UTC)

D²B (Digital Data Bus) -- Possibly incorrectly named.

I couldn't find Digital Data Bus on the IEC website, but I could find domestic digital bus (D2B)

The standards are:

IEC 60933-4 
IEC 61030
IEC 61030-am1

Could someone confirm if this is correct.

Further research suggest that the bus may now be called "Av.Link". "Av.Link" Is defined by the following standard:

EN 50157

The "Av.Link" info was gleaned from the following sources:

http://www.digitaltelevision.gov.uk/pdf_documents/publications/SCART_report_issue.pdf
http://fmt.cs.utwente.nl/Docs/publications/files/111_heerink.pdf
http://www.dtg.org.uk/publications/books/connectivity_guidelines.pdf

Also, the IEC link brings up too many hits. (The correct one being "International Electrotechnical Commission") --Redrob 23:20, 10 Jun 2005 (UTC)

Specifications, and names.

The SCART connector is formally called the "peritelivision connector"

I Believe the standard defining the scart is:

IEC 60807-9 (Rectangular connectors for frequencies below 3 MHz - Part 9: Detail specification for a range of peritelevision connectors)

And also the following British & European standards:

EN 50049-1
BS EN 50049-1
BS EN 50157-1

The source for this info (and an interesting document in it's own right) is this pdf file:

http://www.digitaltelevision.gov.uk/pdf_documents/publications/SCART_report_issue.pdf

--Redrob 23:00, 10 Jun 2005 (UTC)

Right... and it copies entire sentences from our Wikipedia SCART article. I know it copies because I wrote them originally. But it does improve the content.

The speculation section

The speculation section at the end of the article does not conform to NPOV or standard formating for Wikipedia articles. The italicized comments at the beginning are NPOV. Arguments for and against this speculation can be presented but should be sourced. Evidence said to discount this speculation can be presented but only in a NPOV manor in which the article does not appear to take sides. --Cab88

I'd remove that section ASAP, its a real mess and adds nothing to the article! EAi 19:10, 14 November 2005 (UTC)[reply]

Clarify direction of input and output

An anonymous contributor has added (14:08, 14 April 2006) that "Input and output are defined with respect to the TV set". I believe that the directions stated in the article apply to ALL sockets and that the SCART cable will "cross over" the connections. -- Nick 17:03, 14 April 2006 (UTC)[reply]

In my experience at least, 'standard' (fully-wired or composite+audio only) SCART cables swap pins 19 and 20, ie composite input and composite output are swapped. If you are constructing a SCART-enabled device you have to use pin 20 to output composite video (or the composite sync if you're using RGB) and the cable then ensures that it is correctly fed into the 'composite input' pin when you connect it to a television. So yes, you're right, it's defined with respect to all sockets. Knowing this would have saved me much confusion when my picture wouldn't hold sync! [with apologies for anonymity]

re: "RGB connections are not bidirectional. Bidirectional S-Video was added in an extension, although few devices support this, so downstream connections are almost always composite.". Shouldn't this say "upstream"? Blue Basin 49 22:57, 29 October 2006 (UTC)[reply]

drawbacks

seems this unsourced anti-Péritel section is a bit too much. was it done by an english or a republican or some? :) "the connector is too bulky compared to the american VGA?" WTF? why not stating "the RCA connector is cute compared to the Péritel?!"... to say the SCART doesn't allow dolby digital EX ouput is just as stupid as to compare the old Péritel with the VGA scart. are you stupid? these stuff came 20 years later, you cannot compare obsolete technologies with the current standard and call them drawbacks, it doesn't make sense. by the way the shitty RCA cannot be compared with the latest optical TOSLINK for DTS neither, nor the VGA technology. i remember the british (and possibly the aussies too) had a state of the art "RF unit" to connect their pal sega game console through the antenna roof connector :D when we had a secam model with Péritel RVB (RGB SCART) in the 80/90s. it is unfair to compare PERITEL with other stuff than original RCA and Mini-DIN (ushiden). same thing for the cable, you can note many drawbacks with the RCA cable, cheap, thin, too long, fragile, etc. Péritel is a good technology it's just greedy people tend to buy 1€ cheap 5-meter coax cables from china and use these long cables instead of the short (lighter) models. Personally i like the Péritel because i did not had that much drawbacks. the only pin that broke up happened with a 10-pin connector from china or japan. french 21-pin (the original french was 21 not 10) connectors are more expensive but more solid. anyway cheap RCA connectors have drawbacks too, i've experienced plugging a male video RCA connector in a female socket and the whole female socket came with the male (she must be in love or some) when i've unplugged the cable, so what? is it worthy to make a section about this stuff? drawbacks can happen with cheap cables but it's up to the chinese maker (non-standard quality) not to the original design or standard models. how many people with a 10-pin SCART cable or adaptator know they will never reach RGB but will get a shitty CVBS picture instead. these people would cry EUROSCART are shit but this has nothing to do with the genuine Péritel! even the article's top picture is a cheap connector, "Champion" what's that? the musketeers of the distribution... Paris By Night 20:37, 4 January 2007 (UTC)[reply]

Who's so expert so as to decide that "This article or section is in need of attention from an expert on the subject"?

Obviously those who added to the article's contents possess considerable expertise. The article is well written and informative. What was the intention of whoever attached such a tag? To make Wikipedia a treatise on Electronics, among about other sciences? Preposterous! --AVM 20:17, 19 March 2007 (UTC)[reply]