Video Recording

I

Introduction

Video Recording, process of recording images electronically. Two basic technologies—analog and digital—exist to record video images. Analog recording translates an electronic image directly into varying patterns of magnetized metallic compounds on magnetic tape or disc. Digital recording first processes an image electronically into information in the form of 1s and 0s; the information may then be stored on a computer hard drive, on magnetic tape, or as a microscopic pattern on a plastic disc such as a DVD. High-definition versions of digital video (HDTV) recording are now widely used for professional television production. Video recording can be done for broadcasting, playback, editing, webcasting, or archiving.

The techniques used to record images in various video formats share some similarities with those used to record sound (see Sound Recording and Reproduction), and images and sound are usually recorded simultaneously for video recordings. The production of video recordings also retains some general features found in motion pictures and still photography that use photographic film to record images photochemically.

Initial recording of a video image requires some form of video camera or a computer program that generates and records images. A video signal can be recorded with an analog or digital device that receives the signal by antenna, through a cable, from a satellite receiver, or from a direct link to a video camera.

Video recordings typically are viewed with a television screen or a computer monitor. They may also be watched on a personal media device. Video images can also be projected onto a larger surface such as a movie screen. Videotape recorder/playback systems for home use are usually connected directly to a television receiver. Unlike motion picture film, a video recording does not require processing, and so it may be played back immediately. This makes possible the so-called instant replay common to televised sporting events.

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A wide variety of video recording formats exist. Most analog recording formats have become obsolete with increasing adoption of digital formats and technology. Digital recording has many advantages over analog recording. In principle, data in digital form can be copied or edited without losing information. The data can also be easily manipulated with computer programs to alter images, add effects, or adjust color or brightness. By contrast, copying and editing analog video by rerecording degrades the signal. However, when digital recordings are compressed some original data is deliberately left out. Compression makes the data easier to store, to send, or to view. Digital signals are much less affected by interference from outside radio or microwave sources.

II

Types of Video Recordings

Professional video recording that uses high-quality cameras and recording equipment is done for commercial and educational television production, for television advertising, and for motion-picture production. In addition, professional video recordings and broadcasts may be used within corporations or organizations. Large markets also exist for “direct to video” or “direct to DVD” products that are intended for home viewing only and are not distributed to theaters or for broadcast.

Home video recording of television broadcasts is typically done with a videocassette recorder (VCR), a DVD recorder, or a digital video recorder (DVR). These devices can receive signals provided by antenna, by satellite dish, or by cable. Special devices may be needed to convert a digital signal into an analog signal for recording on a VCR, however. DVD recorders and DVRs designed for standard video signals can only record high-definition video signals (HDTV) as standard video signals; special high-definition DVD recorders and DVRs are needed to record in HDTV. VCRs and DVD recorders can also record or copy from other sources such as home video cameras, video players, or files on computers.

DVRs have computer hard drives that can store many more hours of broadcast material than individual videocassettes or DVDs can. Some DVD recorders also have hard drives to record video material. A personal computer can record video material onto its hard drive with a special video capture card.

Portable video cameras and personal computers permit people to make and edit video recordings at home. Video recordings can also be created with digital video features on cell phones, digital cameras, and other portable personal devices.

Several digital video formats have been developed to produce, transmit, and view video recordings on personal computers and over the Internet. Webcasting and podcasting technology mean that video recordings from virtually any source can be available through a computer connected to the Internet, either for downloading or for immediate viewing using streaming video (video sent as small digital packets of data). Websites that allow individuals to post home videos and other video material have become very popular. However, unauthorized use of copyrighted material has led to some restrictions. Television broadcasting over the Internet, known as Internet protocol television (IPTV), is also available. IPTV allows users to select programs for viewing on request, making “time-shifting” video recording unnecessary.

III

History of Video Recording

A

Professional Recording

Professional video recording for television was done with analog magnetic tape formats from the 1950s into the 1990s. The first widely used system was called quadruplex, which used 5-cm (2-in) wide tape and four record/playback tape heads. The tape was on large open reels and was sometimes reused so that recordings of some early television broadcasts were not preserved.

In the 1980s Sony’s Betacam cassette tape was widely adopted for television video recording—Betacam SP remained an industry standard into the 1990s. Digital videotape entered the market in the 1990s, replacing analog tape as digital recording technology was adopted. Since 2000, digital video recording onto hard drives instead of tape has become more common, especially as use of the HDTV format increases.

B

Home Recording

Home video recording became possible in the late 1970s with the introduction of the videocassette recorder (VCR). The device could record video signals from an antenna, a coaxial cable, another VCR, or a video camera. Like the audiocassette introduced in the 1960s, the videocassette contained two rotating spools that allowed a standard length of plastic tape to be played, recorded on, stopped and started, and rewound. Unlike an audiocassette, a videocassette only played and recorded on one side of the tape. The plastic tape had a magnetic metal coating on the side that recorded. A videocassette tape could be played or recorded over many times, but could also wear out or break with excess use. Consumers could buy blank videocassettes for home recording and videocassettes with prerecorded content such as motion pictures. Different recording speeds allowed up to eight hours to be recorded on a videocassette.

Two incompatible formats of analog videotape were originally available: Sony’s Betamax and Victor Company of Japan’s (JVC) Video Home System (VHS). The VHS format eventually became standard for the home video market, in part because VHS tapes were the first to allow two-hour recordings and could hold a full motion picture. Although Betamax failed in the home market, the format (especially as Betacam SP) was widely used for professional video recording. The VHS format remained popular for home video viewing and recording into the 1990s. A major market developed for prerecorded videocassettes of motion pictures and other video entertainment, often rented rather than purchased. Users could program a VCR to record television programs at the time they were broadcast for later playback and viewing, a practice called “time shifting.” Home video cameras (camcorders) were introduced in the 1980s. A number of incompatible formats were developed with different size tapes.

A small market developed in the 1980s and 1990s for high-quality video on a format called laserdisc (LD) or videodisc. A laserdisc was a double-sided disc about the size of a 12-in vinyl record. In this system the original video signals were encoded as tiny elliptical depressions in the surface of the disc. The information was arranged in a single long spiral that was read with a laser. The electronic signals were played back using analog technology. Laserdiscs could only play content created by the manufacturer and could not be used to record new material. However, laserdiscs could contain extra material such as commentary and foreign language sound tracks as well as easy access to particular scenes.

The introduction of the DVD or digital versatile disc (originally called a digital video disc) in 1997 allowed consumers to enjoy high quality video and sound along with the extra features possible with laserdiscs, but on a disc the size of an audio compact disc (CD). Like laserdiscs, DVDs are read by a laser, but technology such as digital compression and double layers of recorded data allows DVDs to hold large amounts of information in less space. Importantly, recordable DVD technology permitted consumers to easily make high-quality video recordings or copies. The popularity of the DVD format helped bring down the price of players and recorders. High-definition DVDs designed for viewing with HDTV equipment were developed in the early 2000s. However, players, recorders, and discs for the high-definition format were more expensive than those for standard DVDs.

The digital video recorder (DVR) was introduced in 1999 and allowed television broadcasts (typically from cable or satellite television) to be recorded onto a hard drive. The hard drive could hold more hours of programming than a VCR or DVD recorder. DVR subscription services connected to the Internet such as TiVo let viewers more easily record large numbers of television programs for later viewing. In addition, DVRs permitted viewers to automatically skip commercials and to pause or rewind live TV broadcasts. DVRs are now provided by some cable or satellite television services. Combined DVRs and DVD recorders allow users to easily make copies of programs recorded on the hard drive.

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