SCART (also known as Péritel or Péritélévision, especially in France, 21-pin EuroSCART in marketing by Sharp in Asia, Euroconector in Spain,[1] EuroAV or EXT, or EIA Multiport in the United States, as an EIA interface) is a French-originated standard and associated 21-pin connector for connecting audio-visual (AV) equipment.

The name SCART comes from Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs, "Radio and Television Receiver Manufacturers' Association", the French organisation that created the connector in the mid-1970s.

SCART was also used for high definition signals such as 720p, 1080i, 1080p with YPbPr connection by some manufacturers, but this usage is scarce due to the advent of HDMI.

Before SCART was introduced, TVs did not offer a standardised way of inputting signals other than RF antenna connectors, and these differed between countries.

[6] The SCART system was intended to simplify connecting AV equipment (including TVs, VCRs, DVD players and games consoles).

A TV can be awakened from standby mode, and it can automatically switch to appropriate AV channel, when the device attached to it through a SCART connector is turned on.

A VCR will often have two SCART sockets, to connect it to the TV ("up", "primary" or "1"), and for video input from a set-top box or other device ("down", "secondary" or "2").

Logically, the TV is on top and ends the "up" chain-path, translating the electrical info into an image and sound.

From the same logical point of view the info stream, wherever it originates, may need processing such as decrypting (decoding, descrambling) or adding captioning/subtitles.

As audio and (composite) video use the same pins on "down" and "up" connectors (and require a crosslinked cable), it is also possible to connect two devices directly to each other without paying attention to the type of the socket.

As straight links (RGB red and blue up) were re-purposed to carry chrominance information, the S-Video pinouts are different for "down" and "up" SCART connectors.

When using S-video, damaging pin 7 or 15 may result in black-white images due to the missing chroma component ("down" and "up" respectively).

SCART enables a device to command the TV to very quickly switch between signals, in order to create overlays in the image.

In order to implement captioning or subtitles, a SCART set-top box does not have to process and send back a complete new video signal, which would require full decoding and re-encoding of the color information, a signal-degrading and costly process, especially given the presence of different standards in Europe.

Some of the wires such as ground, data, switching and RGB connect to the identical pin number at each end.

[citation needed] Due to the relatively high signal voltages used in SCART, "hot plugging" (connecting or disconnecting devices while they are on) is not recommended.

[citation needed] Also, since many TVs are Class II (double-insulated) rather than earthed, the large exposed shield on the SCART connector will be held at approximately half mains voltage if it is plugged into a powered TV with the other end unplugged.

The original specification defined pin 16 as a high frequency (up to 3 MHz) signal that blanked the composite video.

The D²B pins (10 and 12) were used for communicating with satellite dish positioners and for driving magnetic polarisers, before these became incorporated into LNBs.

[11] CENELEC EN 50157-1 introduced AV.link as a standardised protocol to carry advanced control information between devices.

It is a single-wire serial data bus and allows carrying remote control information and to negotiate analogue signal types (e.g. RGB).

Some DVD player manufacturers on some models offered SPDIF only on SCART, and an adapter in order to extract the digital audio signal to send it to a home cinema.

To the present day this connection remains rare, as HDMI, S/PDIF, and TOSLINK can provide multichannel audio, also some TV sets with Surround built in may have an Optical or S/PDIF INPUT, beside Output [citation needed].

Where the Nintendo GameCube and Xbox automatically switch to the proper mode, the PlayStation 2 must be told via a selection in the system menu whether it is to use YPBPR or RGB video.

[12] Some older consoles such as the Master System, Mega Drive/Genesis, and Super Nintendo Entertainment System output RGB, and many older home computers (Amstrad CPC, later ZX Spectrum models, MSX, Amiga, Atari ST, BBC Micro and Acorn Archimedes, etc.)

It was adopted in Japan for the connector's ability to support RGB output format (no compression nor deterioration of original video signals) but, contrary to SCART in Europe, it never saw widespread use on the consumer market.