S Video

Super Video or Separated Video abbreviated S-Video[1] and also known as Y/C is an analog video signal that carries the video data as two separate signals, luma (~brightness) and chroma (colour), unlike composite video, which carries (lower-quality) picture information as a single signal, or component video, which carries (higher-quality) picture information as three separate signals, typically luma and two chroma components. S-Video, as most commonly implemented, carries 480i or 576i resolution video, i.e. standard definition video, but does not carry audio on the same cable. The 4-pin mini-DIN connector (shown at right) is the most common of several S-Video connector types. Other S-Video connector variants include 7-pin locking "dub" connectors used on many professional S-VHS machines, and dual "Y" and "C" BNC connectors, often used for S-Video patch bays. Early Y/C video monitors often used RCA connectors that were switchable between Y/C and composite video input. Y/C is a signal comparison between composite (a) and S-video (b) and this means that S-Video leaves more information from the original video intact, thus having a much-improved image reproduction compared to composite video. Due to the separation of the video into brightness and colour components, S-Video is sometimes considered a type of component video signal, although it is also the most inferior of them, quality-wise, being far surpassed by the more complex component video schemes (like RGB). What differentiates S-Video from these higher component video schemes is that S-Video carries the colour information as one signal. NTSC S-Video colour resolution is typically 120 lines horizontal (approximately 160 pixels edge-to-edge), versus 250 lines horizontal for a DVD-encoded signal, or 30 lines horizontal for standard VCRs. The S-video connection transparently supports this operation. In the late 90s bigger TVs, i.e. 25" started releasing the S-Video port as default bringing other devices supporting it such as Videocassette recorders, DVD players, satellite receivers, Video game consoles and computer Video cards. With the introduction of the Component video the S-Video began to be abandoned by the Home Video market but is still a default in modern video devices as a better alternative to Composite in older TVs, and to output the video signal from a computer or notebook to a TV. Before the mini-DIN plug became standard, S-Video signals were often carried through different types of plugs. The S-Video connector is the most common video-out connector on laptop computers, however many devices with S-Video outputs also have composite outputs. Also, S-Video and RGB are mutually exclusive through SCART, due to the S-Video implementation using the pins allocated for RGB. Non-standard 7-pin mini-DIN connectors are used on laptops and video cards. The 7-pin socket accepts the 4-pin plug (unlike the standard 7-pin socket) and the S-video signals are available on the matching pins. When a 7-pin plug is inserted, one of the extra pins carries a CVBS composite video signal for non S-video displays. Two variations of the 9-pin din connector are used by video cards with Video In Video Out (VIVO) capability. S-video uses 2 parallel monochrome composite video signals to represent the chroma and luma subcarriers respectively. S-Video is commonly used throughout the world. Almost all TV-out connectors on graphics cards can support S-Video. S-Video cables are used for computer-to-TV output for business or home usage. Due to a lack of bandwidth, S-Video connections are generally not considered suitable for high-definition video signals.