| Composite Video |
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Information AboutComposite Video |
| CATEGORIES ABOUT COMPOSITE VIDEO | |
| analog video connectors | |
| television technology | |
| film and video technology | |
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Composite video cannot easily be directed to any broadcast channel simply by modulating the proper RF carrier frequency with it. Most analogue home video equipment records a signal in (roughly) composite format: LaserDisc s store a true composite signal, while VHS tapes use a slightly modified composite signal. These devices then give the user the option of outputting the raw signal, or modulating it on to a VHF or UHF frequency to appear on a selected TV channel. In typical home applications, the composite video signal is typically connected using an RCA Jack , normally yellow (often accompanied with red and white for right and left audio channels respectively). BNC connectors and higher quality co-axial cable are often used in more professional applications. In Europe, SCART connections are often used instead of RCA jacks — though SCART can also carry far superior RGB Component Video signals (and to a lesser extent, S-Video ), so where available, RGB is used instead of composite video with computers, video game consoles, and DVD players. Some devices that connect to a TV, such as Videogame Console s (and the ubiquitous Home Computer s of the 1980s ), naturally output a composite signal. This may then be converted to RF with an external box known as an RF Modulator that generates the proper carrier (often for channel 3 or 4 in North America ). The RF modulator is preferably left outside the console so the RF doesn't interfere with the components inside the machine. VCR s and similar devices already have to deal with RF signals in their tuners, so the modulator is located inside the box. Also, most early home computers usually employed an internal RF modulator. The process of modulating RF with the original video signal, and then demodulating the original signal again in the TV, introduces several losses into the signal. RF is also "noisy" because of all of the video and radio signals already being broadcast, so this conversion also typically adds noise or interference to the signal as well. For these reasons, it is typically best to use composite connections instead of RF connections if possible. Almost all modern video equipment has composite connectors, so this typically isn't a problem. However, just as the modulation and demodulation of RF loses quality, the mixing of the various signals into the original composite signal does the same. This has led to a proliferation of systems such as S-Video and Component Video to separate out one or more of the mixed signals. Composite video is often designated by the CVBS acronym, meaning either " Color , Video , Blank and Sync ", "Composite Video Baseband Signal", "Composite Video Burst Signal", or "Composite Video with Burst and Sync". TRIVIA
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