VCR Plus+, G-Code, VideoPlus+ and ShowView are different names for the same scheduling system for programming VCRs and digital video recorders. These names are all registered trademarks of Macrovision, whose corporate predecessor, Gemstar, developed these algorithms for use in integrated endecs.
Before the advent of on-screen displays, the only interface available for programming a home video recorder was a small VFD, LED or LCD panel and a small number of buttons. Correctly setting up a recording for a specific program was therefore a somewhat complex operation for many people. G-Code, VideoPlus+ and ShowView were introduced in the late 1980s to remove this difficulty.
The central concept of the system is a unique number, a PlusCode, assigned to each program, and published in television listings in newspapers and magazines (such as TV Guide ). To record a program, the code number is taken from the newspaper and input into the video recorder, which would then record on the correct channel at the correct time. The code could also be entered into a dedicated remote control device that would then control the VCR. The number is generated by an algorithm from the date, time and channel of the program; as a result, it does not rely on an over-the-air channel to serve as a conduit to ensure the recording is properly timed. This means it will not compensate for a disrupted schedule due to live sporting events or bulletins for breaking news events, however many video recorders with these systems also incorporate Programme Delivery Control (PDC) and use that to alter times if possible.
The system has been licensed to television and VCR manufacturers in about 40 countries, but is branded under different names depending on the country. It is known as VCR Plus+, VCR Plus+ Silver and VCR Plus+ Gold in the United States and Canada; G-Code in Japan, China, New Zealand and Australia; VideoPlus+ in Ireland, the United Kingdom, and Japan; and ShowView in the rest of Europe as well as in South Africa. The system is branded as VideoPlus+/ShowView in Europe due to an existing trademark registration for "VCR" by Philips in that continent, and as G-Code (the "G" standing for the system's developer Gemstar) in Japan because VCR is not a common abbreviation there ("VTR," for videotape recorder, is used instead). Japan initially used the name Video Plus+ and later changed to G-Code, an example of this is the Victor (JVC) HR-880. Because television programming schedules are different, the coding has to be adjusted in each of the regions and recording equipment is not interchangeable.
The actual algorithms used to encode and decode the television guide values from and to their time representations were published in 1992, but only for six-digit codes or less. [1] [2]
Source code for seven and eight digit codes was written in C and Perl and posted anonymously in 2003. [3]
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communication channels. Many communication channels are subject to channel noise, and thus errors may be introduced during transmission from the source to a receiver. Error detection techniques allow detecting such errors, while error correction enables reconstruction of the original data in many cases.
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields per second, and associated with CCIR analogue broadcast television systems B, D, G, H, I or K. The articles on analog broadcast television systems further describe frame rates, image resolution, and audio modulation.
A set-top box (STB), also colloquially known as a cable box or receiver and historically television decoder, is an information appliance device that generally contains a TV-tuner input and displays output to a television set and an external source of signal, turning the source signal into content in a form that can then be displayed on the television screen or other display device. They are used in cable television, satellite television, and over-the-air television systems as well as other uses.
TiVo is a digital video recorder (DVR) developed and marketed by Xperi and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs, whose features include "OnePass" schedules which record every new episode of a series, and "WishList" searches which allow the user to find and record shows that match their interests by title, actor, director, category, or keyword. TiVo also provides a range of features when the TiVo DVR is connected to a home network, including film and TV show downloads, advanced search, online scheduling, and at one time, personal photo viewing and local music playback.
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems which, in turn, were replaced by flat panel displays of several types.
VHS is a standard for consumer-level analog video recording on tape cassettes invented in 1976 by the Victor Company of Japan and was the competitor to the ill-fated Sony Betamax system.
S-VHS (スーパー・ヴィエイチエス), the common initialism for Super VHS, is an improved version of the VHS standard for consumer-level video recording. Victor Company of Japan introduced S-VHS in Japan in April 1987, with their JVC-branded HR-S7000 VCR, and in certain overseas markets soon afterward. By the end of 1987, the first S-VHS VCR models from other competitors included Hitachi VT-2700A, Mitsubishi HS-423UR, Panasonic PV-S4764, RCA VPT-695HF, and Toshiba SV-950.
TV Guide is an American digital media company that provides television program listings information as well as entertainment and television-related news.
Programme delivery control (PDC) is specified by the standard ETS 300 231, published by the European Telecommunications Standards Institute (ETSI). This specifies the signals sent as hidden codes in the teletext service, indicating when transmission of a programme starts and finishes.
A digital video recorder (DVR) is an electronic device that records video in a digital format to a disk drive, USB flash drive, SD memory card, SSD or other local or networked mass storage device. The term includes set-top boxes with direct to disk recording, portable media players and TV gateways with recording capability, and digital camcorders. Personal computers are often connected to video capture devices and used as DVRs; in such cases the application software used to record video is an integral part of the DVR. Many DVRs are classified as consumer electronic devices; such devices may alternatively be referred to as personal video recorders (PVRs), particularly in Canada. Similar small devices with built-in displays and SSD support may be used for professional film or video production, as these recorders often do not have the limitations that built-in recorders in cameras have, offering wider codec support, the removal of recording time limitations and higher bitrates.
Betacam is a family of half-inch professional videocassette products developed by Sony in 1982. In colloquial use, "Betacam" singly is often used to refer to a Betacam camcorder, a Betacam tape, a Betacam video recorder or the format itself.
A DVD recorder is an optical disc recorder that uses optical disc recording technologies to digitally record analog or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in television studios or home theater systems.
U-matic is an analogue recording videocassette format first shown by Sony in prototype in October 1969, and introduced to the market in September 1971. It was among the first video formats to contain the videotape inside a cassette, as opposed to the various reel-to-reel or open-reel formats of the time. The videotape is 3⁄4 in (19 mm) wide, so the format is often known as "three-quarter-inch" or simply "three-quarter", compared to open reel videotape formats in use, such as 1 in (25 mm) type C videotape and 2 in (51 mm) quadruplex videotape.
An on-screen display (OSD) is an image superimposed on a screen picture, commonly used by modern television sets, VCRs, and DVD players to display information such as volume, channel, and time.
Electronic programming guides (EPGs) and interactive programming guides (IPGs) are menu-based systems that provide users of television, radio and other media applications with continuously updated menus that display scheduling information for current and upcoming broadcast programming. Some guides also feature backward scrolling to promote their catch up content. They are commonly known as guides or TV guides.
Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen. The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format, typically displayed on a television or a dumb terminal, but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel.
Guide Plus+, TV Guide On Screen, TV Guide Daily, TV Guide Plus+ and Guide Plus+ Gold or G-Guide are brand names for an interactive electronic program guide (EPG) system that is used in consumer electronics products, such as television sets, DVD recorders, personal video recorders, and other digital television devices. It offers interactive on-screen program listings that enable viewers to navigate, sort, select and schedule television programming for viewing and recording. The differing names are only used for marketing purposes – the entire system is owned by Rovi Corporation, the successor to Gemstar-TV Guide International. In 2016, Rovi acquired digital video recorder maker TiVo Inc., and renamed itself TiVo Corporation.
Gemstar–TV Guide International, Inc. was a media company that licensed interactive program guide technology to multichannel video programming distributors such as cable and satellite television providers, and consumer electronics manufacturers; video recorder scheduling codes under brands such as VCR Plus; as well as serving as publishers of TV Guide magazine as well as operators of tvguide.com, owners of TV Guide Network and TVG Network, and provided various related services. On May 2, 2008, Gemstar–TV Guide International, Inc. became a wholly owned subsidiary of Macrovision Solutions Corporation, which later changed its name to Rovi Corporation on July 16, 2009.
In broadcasting, time shifting is the recording of programming to a storage medium to be viewed or listened to after the live broadcasting. Typically, this refers to TV programming but it can also refer to radio shows via podcasts.