LaserDisc

qas: question: Did LaserDisks offer higher or lower quality sound and picture than VHS?
answers: text: higher-quality

question: Why didn't LaserDisk gain popularity in North America?
answers: text: high costs for the players and video titles themselves and the inability to record TV programming

question: With whom was LaserDisk a popular choice for it's picture and sound quality?
answers: text: videophiles and film enthusiasts

question: In what city was LaserDisk used as a popular rental medium in the 1990s?
answers: text: Hong Kong
context: Although the format was capable of offering higher-quality video and audio than its consumer rivals, the VHS and Betamax videocassette systems, LaserDisc never managed to gain widespread use in North America, largely due to high costs for the players and video titles themselves and the inability to record TV programming. It also remained a largely obscure format in Europe and Australia. By contrast, the format was much more popular in Japan and in the more affluent regions of Southeast Asia, such as Hong Kong, Singapore, and Malaysia, being the prevalent rental video medium in Hong Kong during the 1990s. Its superior video and audio quality did make it a somewhat popular choice among videophiles and film enthusiasts during its lifespan.

qas: question: Where was LaserDisc first available?
answers: text: Atlanta, Georgia

question: How many years after VHS was LaserDisk released?
answers: text: two years

question: Under what name was LaserDisc originally marketed?
answers: text: MCA DiscoVision

question: How did the first viewers refer to the media?
answers: text: "Video Long Play"
context: LaserDisc was first available on the market, in Atlanta, Georgia, on December 15, 1978, two years after the introduction of the VHS VCR, and four years before the introduction of the CD (which is based on laser disc technology). Initially licensed, sold, and marketed as MCA DiscoVision (also known as simply "DiscoVision") in North America in 1978, the technology was previously referred to internally as Optical Videodisc System, Reflective Optical Videodisc, Laser Optical Videodisc, and Disco-Vision (with a dash), with the first players referring to the format as "Video Long Play".

qas: question: Who purchased the majority stake and re-marketed the product in 1980?
answers: text: Pioneer Electronics

question: Was Laserdisk officially or unofficially reffered to as "Laser Videodisc"?
answers: text: unofficially

question: Did MCA produce the disc or the players after being bought out?
answers: text: discs

question: Who were the scientists that worked on the early research for Laserdiscs?
answers: text: Richard Wilkinson, Ray Dakin and John Winslow

question: What company did the early Laserdisc researchers later found?
answers: text: Optical Disc Corporation (now ODC Nimbus)
context: Pioneer Electronics later purchased the majority stake in the format and marketed it as both LaserVision (format name) and LaserDisc (brand name) in 1980, with some releases unofficially referring to the medium as "Laser Videodisc". Philips produced the players while MCA produced the discs. The Philips-MCA cooperation was not successful, and discontinued after a few years. Several of the scientists responsible for the early research (Richard Wilkinson, Ray Dakin and John Winslow) founded Optical Disc Corporation (now ODC Nimbus).

qas: question: What product replaced LaserDisc in North America by the early 2000s?
answers: text: DVD

question: Who chose LaserFisc for their Domesday Project in the mid-1980s?
answers: text: British Broadcasting Corporation (BBC)

question: What was the BBC Domesday Project?
answers: text: a school-based project to commemorate 900 years since the original Domesday Book in England

question: Which country still exported players to North America until 2001?
answers: text: Japan
context: By the early 2000s, LaserDisc was completely replaced by DVD in the North American retail marketplace, as neither players nor software were then produced. Players were still exported to North America from Japan until the end of 2001. The format has retained some popularity among American collectors, and to a greater degree in Japan, where the format was better supported and more prevalent during its life. In Europe, LaserDisc always remained an obscure format. It was chosen by the British Broadcasting Corporation (BBC) for the BBC Domesday Project in the mid-1980s, a school-based project to commemorate 900 years since the original Domesday Book in England. From 1991 up until the early 2000s, the BBC also used LaserDisc technology to play out the channel idents.

qas: question: How large was a standard LaserDisc?
answers: text: 30 cm (12 in) in diameter

question: What numbers are used in Binary information coding?
answers: text: 1s and 0s

question: Were the ealiest LaserDiscs in 1978 analog or digitally formatted?
answers: text: analog
context: The standard home video LaserDisc was 30 cm (12 in) in diameter and made up of two single-sided aluminum discs layered in plastic. Although appearing similar to compact discs or DVDs, LaserDiscs used analog video stored in the composite domain (having a video bandwidth approximately equivalent to the 1-inch (25 mm) C-Type VTR format) with analog FM stereo sound and PCM digital audio. The LaserDisc at its most fundamental level was still recorded as a series of pits and lands much like CDs, DVDs, and even Blu-ray Discs are today. However, while the encoding is of a binary nature, the information is encoded as analog pulse width modulation with a 50% duty cycle, where the information is contained in the lengths and spacing of the pits. In true digital media the pits, or their edges, directly represent 1s and 0s of a binary digital information stream. Early LaserDiscs featured in 1978 were entirely analog but the format evolved to incorporate digital stereo sound in CD format (sometimes with a TOSlink or coax output to feed an external DAC), and later multi-channel formats such as Dolby Digital and DTS.

qas: question: What was the length capacity of the CAA55 format?
answers: text: 55 minutes 5 seconds

question: Why was Back to the Future released with analog sound?
answers: text: due to the length of the title and the desire to keep the film on one disc

question: What was the maximum length of the CAA60 format?
answers: text: 60 minutes 5 seconds

question: How many works were released to the public with the CAA70 format?
answers: text: There are not any known uses of this format on the consumer market
context: As Pioneer introduced Digital Audio to LaserDisc in 1985, they further refined the CAA format. CAA55 was introduced in 1985 with a total playback capacity per side of 55 minutes 5 seconds, reducing the video capacity to resolve bandwidth issues with the inclusion of Digital Audio. Several titles released between 1985 and 1987 were analog audio only due to the length of the title and the desire to keep the film on one disc (e.g., Back to the Future). By 1987, Pioneer had overcome the technical challenges and was able to once again encode in CAA60, allowing a total of 60 minutes 5 seconds. Pioneer further refined CAA, offering CAA45, encoding 45 minutes of material, but filling the entire playback surface of the side. Used on only a handful of titles, CAA65 offered 65 minutes 5 seconds of playback time per side. There are a handful of titles pressed by Technidisc that used CAA50. The final variant of CAA is CAA70, which could accommodate 70 minutes of playback time per side. There are not any known uses of this format on the consumer market.

qas: question: What was the difference between LaserDisc and LaserVision in the UK?
answers: text: "LaserVision" is used to refer to discs with analog sound, while "LaserDisc" is used for those with digital audio

question: The Phantom Menace was one of the first home videos to use what sound format?
answers: text: 6.1 channel Dolby Digital EX Surround.

question: What sound formatting do DVDs use?
answers: text: Dolby Digital audio in digital form
context: Sound could be stored in either analog or digital format and in a variety of surround sound formats; NTSC discs could carry two analog audio tracks, plus two uncompressed PCM digital audio tracks, which were (EFM, CIRC, 16-bit and 44.056 kHz sample rate). PAL discs could carry one pair of audio tracks, either analog or digital and the digital tracks on a PAL disc were 16-bit 44.1 kHz as on a CD; in the UK, the term "LaserVision" is used to refer to discs with analog sound, while "LaserDisc" is used for those with digital audio. The digital sound signal in both formats are EFM-encoded as in CD. Dolby Digital (also called AC-3) and DTS—which are now common on DVD titles—first became available on LaserDisc, and Star Wars: Episode I – The Phantom Menace (1999) which was released on LaserDisc in Japan, is among the first home video releases ever to include 6.1 channel Dolby Digital EX Surround. Unlike DVDs, which carry Dolby Digital audio in digital form, LaserDiscs store Dolby Digital in a frequency modulated form within a track normally used for analog audio. Extracting Dolby Digital from a LaserDisc required a player equipped with a special "AC-3 RF" output and an external demodulator in addition to an AC-3 decoder. The demodulator was necessary to convert the 2.88 MHz modulated AC-3 information on the disc into a 384 kbit/s signal that the decoder could handle. DTS audio, when available on a disc, replaced the digital audio tracks; hearing DTS sound required only an S/PDIF compliant digital connection to a DTS decoder.

qas: question: What competition caused LaserDisc sales to decline?
answers: text: DVD's growing popularity

question: Did all AV receivers carry the demodulator circuits necessary for LaserDiscs, or only high-end models?
answers: text: higher-end

question: What did the Onkyo outboard demodulator covert the RF AC-2 signal to?
answers: text: 6-channel analog audio
context: In the mid to late 1990s many higher-end AV receivers included the demodulator circuit specifically for the LaserDisc players RF modulated Dolby Digital AC-3 signal. By the late 1990s with LaserDisc players and disc sales declining due to DVD's growing popularity the AV receiver manufacturers removed the demodulator circuit. Although DVD players were capable of playing Dolby Digital tracks, the signal out of DVD player were not in a modulated form and not compatible with the inputs designed for LaserDisc AC-3. Outboard demodulators were available for a period that convert the AC-3 signal to standard Dolby Digital signal that was compatible with the standard Dolby Digital/PCM inputs on capable AV receivers. Another type marketed by Onkyo and others converted the RF AC-3 signal to 6-channel analog audio.

qas: question: Was sound quality from disc to disc and between players consistent or varied?
answers: text: varied greatly

question: Was analog or digital formatting more popular with enthusiasts?
answers: text: digital

question: What result did adding CX Noise Reduction have on analog discs?
answers: text: improved the signal-noise ratio of their audio

question: Which company added digital sound option when re-releasing movies?
answers: text: Universal
context: At least where the digital audio tracks were concerned, the sound quality was unsurpassed at the time compared to consumer videotape, but the quality of the analog soundtracks varied greatly depending on the disc and, sometimes, the player. Many early and lower-end LD players had poor analog audio components, and many early discs had poorly mastered analog audio tracks, making digital soundtracks in any form most desirable to serious enthusiasts. Early DiscoVision and LaserDisc titles lacked the digital audio option, but many of those movies received digital sound in later re-issues by Universal, and the quality of analog audio tracks generally got far better as time went on. Many discs that had originally carried old analog stereo tracks received new Dolby Stereo and Dolby Surround tracks instead, often in addition to digital tracks, helping boost sound quality. Later analog discs also applied CX Noise Reduction, which improved the signal-noise ratio of their audio.

qas: question: Which channel would not work in conjunction with AC-3 audio?
answers: text: right analog audio channel

question: What audio playback options were available if an AC-3 output was not present?
answers: text: digital Dolby Surround or stereo audio tracks

question: What happens to the right channel in a player that doesn't recognize AC-3?
answers: text: garbage (static) output
context: Both AC-3 and DTS surround audio were clumsily implemented on LaserDiscs, leading to some interesting player- and disc-dependent issues. A disc that included AC-3 audio forfeited the right analog audio channel to the modulated AC-3 RF stream. If the player did not have an AC-3 output available, the next most attractive playback option would be the digital Dolby Surround or stereo audio tracks. The reason for this is the RF signal needs to bypass the audio circuitry in order to be properly processed by the demodulator. If either the player did not support digital audio tracks (common in older players), or the disc did not include digital audio tracks at all (uncommon for a disc which is mastered with an AC-3 track), the only remaining option was to fall back to a monophonic presentation of the left analog audio track. However, many older analog-only players not only failed to output AC-3 streams correctly, but were not even aware of their potential existence. Such a player will happily play the analog audio tracks verbatim, resulting in garbage (static) output in the right channel.

qas: question: Are integrated AC-3 demodulators common in LaserDisc players or a rare find?
answers: text: rare

question: How many 5.1 surround sound options exist in LaserDiscs?
answers: text: Only one

question: What type of decoder logic is common in 1990s A/V receivers?
answers: text: DTS
context: Only one 5.1 surround sound option exists on a given LaserDisc (either Dolby Digital or DTS), so if surround sound is desired, the disc must be matched to the capabilities of the playback equipment (LD Player and Receiver/Decoder) by the purchaser. A fully capable LaserDisc playback system includes a newer LaserDisc player that is capable of playing digital tracks, has a digital optical output for digital PCM and DTS audio, is aware of AC-3 audio tracks, and has an AC-3 coaxial output; an external or internal AC-3 RF demodulator and AC-3 decoder; and a DTS decoder. Many 1990s A/V receivers combine the AC-3 decoder and DTS decoder logic, but an integrated AC-3 demodulator is rare both in LaserDisc players and in later A/V receivers.

qas: question: Which has a longer playing time: PAL LaserDiscs or NTSC discs?
answers: text: PAL LaserDiscs

question: How many audio tracks do PAL LaserDiscs have?
answers: text: two

question: Which two audio options are available on PAL LaserDiscs?
answers: text: two analog-only tracks on older PAL LDs, or two digital-only tracks on newer discs
context: PAL LaserDiscs have a slightly longer playing time than NTSC discs, but have fewer audio options. PAL discs only have two audio tracks, consisting of either two analog-only tracks on older PAL LDs, or two digital-only tracks on newer discs. In comparison, later NTSC LDs are capable of carrying four tracks (two analog and two digital). On certain releases, one of the analog tracks is used to carry a modulated AC-3 signal for 5.1 channel audio (for decoding and playback by newer LD players with an "AC-3 RF" output). However, older NTSC LDs made before 1984 (such as the original DiscoVision discs) only have two analog audio tracks.

qas: question: What was the name of the first solid-state laser consumer LaserDisc player?
answers: text: LD-700

question: Besides a solid-state laser, what else was unique about the LD-700?
answers: text: first LD player to load from the front and not the top

question: When did Pioneer release the LD-700?
answers: text: March 1984

question: Which company continued to use gas-lasers in industrial models of LD players although they were no longer used in consumer models?
answers: text: Philips
context: In March 1984, Pioneer introduced the first consumer player with a solid-state laser, the LD-700. It was also the first LD player to load from the front and not the top. One year earlier Hitachi introduced an expensive industrial player with a laser diode, but the player, which had poor picture quality due to an inadequate dropout compensator, was made only in limited quantities. After Pioneer released the LD-700, gas lasers were no longer used in consumer players, despite their advantages, although Philips continued to use gas lasers in their industrial units until 1985.

qas: question: Which three names did MCA use for LaserDisc technology during its development?
answers: text: Optical Videodisc System, "Reflective Optical Videodisc" or "Laser Optical Videodisc"

question: To what did MCA change the name to in 1969?
answers: text: Disco-Vision

question: When did MCA remove the hyphen from the name Disco-Vision?
answers: text: 1978

question: Which company owned the rights to the world's largest collection of films during the 1970s?
answers: text: MCA

question: Consumer sales of MCA films began in 1978 with what movie?
answers: text: Jaws
context: During its development, MCA, which co-owned the technology, referred to it as the Optical Videodisc System, "Reflective Optical Videodisc" or "Laser Optical Videodisc", depending on the document; changing the name once in 1969 to Disco-Vision and then again in 1978 to DiscoVision (without the hyphen), which became the official spelling. Technical documents and brochures produced by MCA Disco-Vision during the early and mid-'70s also used the term "Disco-Vision Records" to refer to the pressed discs. MCA owned the rights to the largest catalog of films in the world during this time, and they manufactured and distributed the DiscoVision releases of those films under the "MCA DiscoVision" software and manufacturing label; consumer sale of those titles began on December 15, 1978, with the aforementioned Jaws.

qas: question: What did VLP stand for in English-speaking countries?
answers: text: Video Long-Play

question: What was the first consumer VLP player?
answers: text: Magnavox VH-8000

question: Which group officially chose the name "Laservision"?
answers: text: The LaserVision Association

question: The Laservision Association was comprised of which companies?
answers: text: MCA, Universal-Pioneer, IBM, and Philips/Magnavox
context: Philips' preferred name for the format was "VLP", after the Dutch words Video Langspeel-Plaat ("Video long-play disc"), which in English-speaking countries stood for Video Long-Play. The first consumer player, the Magnavox VH-8000 even had the VLP logo on the player. For a while in the early and mid-1970s, Philips also discussed a compatible audio-only format they called "ALP", but that was soon dropped as the Compact Disc system became a non-compatible project in the Philips corporation. Until early 1980, the format had no "official" name. The LaserVision Association, made up of MCA, Universal-Pioneer, IBM, and Philips/Magnavox, was formed to standardize the technical specifications of the format (which had been causing problems for the consumer market) and finally named the system officially as "LaserVision".

qas: question: Which company joined a 50/50 partnership with MCA in 1977?
answers: text: Pioneer Electronics

question: In what year was the first Universal-Pioneer player released?
answers: text: 1980

question: What was the name of the first Universal-Pioneer player?
answers: text: the VP-1000

question: Which singer did an ad for the LD-700 player in 1984?
answers: text: Ray Charles
context: Pioneer Electronics also entered the optical disc market in 1977 as a 50/50 joint-venture with MCA called Universal-Pioneer and manufacturing MCA designed industrial players under the MCA DiscoVision name (the PR-7800 and PR-7820). For the 1980 launch of the first Universal-Pioneer player, the VP-1000 was noted as a "laser disc player", although the "LaserDisc" logo displayed clearly on the device. In 1981, "LaserDisc" was used exclusively for the medium itself, although the official name was "LaserVision" (as seen at the beginning of many LaserDisc releases just before the start of the film). However, as Pioneer reminded numerous video magazines and stores in 1984, LaserDisc was a trademarked word, standing only for LaserVision products manufactured for sale by Pioneer Video or Pioneer Electronics. A 1984 Ray Charles ad for the LD-700 player bore the term "Pioneer LaserDisc brand videodisc player". From 1981 until the early 1990s, all properly licensed discs carried the LaserVision name and logo, even Pioneer Artists titles.

qas: question: What other companies did MCA manufacture discs for?
answers: text: Paramount, Disney and Warner Bros

question: What quirk is present in MCA's release of Howard the Duck?
answers: text: only the start credits shown in widescreen before changing to 4:3 for the rest of the film

question: What is unique about the LaserDisc release of E.T.?
answers: text: only format to include the cut scene of Harrison Ford playing the part of the school headmaster

question: Which film is only available with its original score in LD format , even today?
answers: text: The Electric Horseman
context: During the early years, MCA also manufactured discs for other companies including Paramount, Disney and Warner Bros. Some of them added their own names to the disc jacket to signify that the movie was not owned by MCA. After Discovision Associates shut down in early 1982, Universal Studio's videodisc software label, called MCA Videodisc until 1984, began reissuing many DiscoVision titles. Unfortunately, quite a few, such as Battlestar Galactica and Jaws, were time-compressed versions of their CAV or CLV Disco Vision originals. The time-compressed CLV re-issue of Jaws no longer had the original soundtrack, having had incidental background music replaced for the video disc version due to licensing cost (the music would not be available until the THX LaserDisc box set was released in 1995). One Universal/Columbia co-production issued by MCA Disco Vision in both CAV and CLV versions, The Electric Horseman, is still not available in any other home video format with its original score intact; even the most recent DVD release has had substantial music replacements of both instrumental score and Willie Nelson's songs. An MCA release of Universal's Howard the Duck, sees only the start credits shown in widescreen before changing to 4:3 for the rest of the film. For many years this was the only disc-based release of the film, until widescreen DVD formats were released with extras. Also, the LaserDisc release of E.T. the Extra-Terrestrial is the only format to include the cut scene of Harrison Ford playing the part of the school headmaster telling off Elliott for letting the frogs free in the biology class.

qas: question: How many horizontal TVL lines did LaserDisc have in comparison to VHS's 240?
answers: text: 425

question: Which medium was chapter based like DVD format, Laserdisc or VHS?
answers: text: LaserDisc

question: Which medium allowed for multiple audio tracks, Laserdisc or VHS?
answers: text: LaserDisc
context: LaserDisc had a number of advantages over VHS. It featured a far sharper picture with a horizontal resolution of 425 TVL lines for NTSC and 440 TVL lines for PAL discs, while VHS featured only 240 TVL lines with NTSC. It could handle analog and digital audio where VHS was mostly analog only (VHS can have PCM audio in professional applications but is uncommon), and the NTSC discs could store multiple audio tracks. This allowed for extras like director's commentary tracks and other features to be added onto a film, creating "Special Edition" releases that would not have been possible with VHS. Disc access was random and chapter based, like the DVD format, meaning that one could jump to any point on a given disc very quickly. By comparison, VHS would require tedious rewinding and fast-forwarding to get to specific points.

qas: question: Were Laserdiscs initially cheaper or more costly to produce than their VHS counterparts?
answers: text: cheaper

question: How many parts does a VHS tape have that must be manufactured?
answers: text: at least 14

question: How much did LaserDiscs cost to produce by the end of the 1980s?
answers: text: $5.00 per two-sided disc

question: How much did VHS cost to produce by the 1990s?
answers: text: as little as $1.00
context: LaserDiscs were initially cheaper than videocassettes to manufacture, because they lacked the moving parts and plastic outer shell that are necessary for VHS tapes to work, and the duplication process was much simpler. A VHS cassette has at least 14 parts including the actual tape while LaserDisc has one part with five or six layers. A disc can be stamped out in a matter of seconds whereas duplicating videotape required a complex bulk tape duplication mechanism and was a time-consuming process. However, by the end of the 1980s, average disc-pressing prices were over $5.00 per two-sided disc, due to the large amount of plastic material and the costly glass-mastering process needed to make the metal stamper mechanisms. Due to the larger volume of demand, videocassettes quickly became much cheaper to duplicate, costing as little as $1.00 by the beginning of the 1990s.

qas: question: Were Laserdiscs or VHS more durable in the long run?
answers: text: LaserDiscs

question: Why is physical contact with a VHS tape less desirable than an optical reading?
answers: text: progressive wear with each use

question: Where do VHS tapes store their information?
answers: text: magnetic coating
context: LaserDiscs potentially had a much longer lifespan than videocassettes. Because the discs were read optically instead of magnetically, no physical contact needs to be made between the player and the disc, except for the player's clamp that holds the disc at its center as it is spun and read. As a result, playback would not wear the information-bearing part of the discs, and properly manufactured LDs would theoretically last beyond one's lifetime. By contrast, a VHS tape held all of its picture and sound information on the tape in a magnetic coating which is in contact with the spinning heads on the head drum, causing progressive wear with each use (though later in VHS's lifespan, engineering improvements allowed tapes to be made and played back without contact). Also, the tape was thin and delicate, and it was easy for a player mechanism, especially on a low quality or malfunctioning model, to mishandle the tape and damage it by creasing it, frilling (stretching) its edges, or even breaking it.

qas: question: How is data stored on DVDs?
answers: text: digital blocks which make up each independent frame

question: What device seperated the black and white and color signals in LaserDiscs?
answers: text: the receiver

question: Are comb filters exact, or is some data smudged?
answers: text: comb filters almost inevitably smudge some detail

question: In what areas are comb filters most likely to lose detail?
answers: text: low-contrast details like skin tones
context: LaserDisc was a composite video format: the luminance (black and white) and chrominance (color) information were transmitted in one signal, separated by the receiver. While good comb filters can do so adequately, these two signals cannot be completely separated. On DVDs, data is stored in the form of digital blocks which make up each independent frame. The signal produced is dependent on the equipment used to master the disc. Signals range from composite and split, to YUV and RGB. Depending upon which format is used, this can result in far higher fidelity, particularly at strong color borders or regions of high detail (especially if there is moderate movement in the picture) and low-contrast details like skin tones, where comb filters almost inevitably smudge some detail.

qas: question: Do LaserDiscs or DVD use analog video?
answers: text: LaserDiscs

question: Are DVDs partially or entirely digital?
answers: text: entirely

question: What is contrast banding?
answers: text: subtle visible lines in gradient areas

question: What step of the DVD production process causes contrast banding?
answers: text: MPEG-2 encoding process
context: In contrast to the entirely digital DVD, LaserDiscs use only analog video. As the LaserDisc format is not digitally encoded and does not make use of compression techniques, it is immune to video macroblocking (most visible as blockiness during high motion sequences) or contrast banding (subtle visible lines in gradient areas, such as out-of-focus backgrounds, skies, or light casts from spotlights) that can be caused by the MPEG-2 encoding process as video is prepared for DVD. Early DVD releases held the potential to surpass their LaserDisc counterparts, but often managed only to match them for image quality, and in some cases, the LaserDisc version was preferred. However, proprietary human-assisted encoders manually operated by specialists can vastly reduce the incidence of artifacts, depending on playing time and image complexity. By the end of LaserDisc's run, DVDs were living up to their potential as a superior format.

qas: question: How does LaserDisc operation vary from DVD?
answers: text: the transport mechanism always obeys commands from the user

question: What are "User Protected Options" on DVDs?
answers: text: where content protection code instructs the player to refuse commands to skip a specific part

question: Where are User Protected Options commonly found on DVDs?
answers: text: copyright warnings

question: Which format, LaserDisc or DVD, gives the user the most control over playback?
answers: text: LaserDisc
context: LaserDisc players can provide a great degree of control over the playback process. Unlike many DVD players, the transport mechanism always obeys commands from the user: pause, fast-forward, and fast-reverse commands are always accepted (barring, of course, malfunctions). There were no "User Prohibited Options" where content protection code instructs the player to refuse commands to skip a specific part (such as fast forwarding through copyright warnings). (Some DVD players, particularly higher-end units, do have the ability to ignore the blocking code and play the video without restrictions, but this feature is not common in the usual consumer market.)

qas: question: What does the repair+skip feature on newer DVD players do?
answers: text: filling in unreadable areas of the picture with blank space or a frozen frame of the last readable image and sound

question: Which format, DVD or Laserdisc, can become unreadable with damage?
answers: text: DVD

question: Will the same size scratch cause more problems for a DVD or LaserDisc?
answers: text: DVD
context: Damaged spots on a LaserDisc can be played through or skipped over, while a DVD will often become unplayable past the damage. Some newer DVD players feature a repair+skip algorithm, which alleviates this problem by continuing to play the disc, filling in unreadable areas of the picture with blank space or a frozen frame of the last readable image and sound. The success of this feature depends upon the amount of damage. LaserDisc players, when working in full analog, recover from such errors faster than DVD players. Direct comparison here is almost impossible due to the sheer size differences between the two media. A 1 in (3 cm) scratch on a DVD will probably cause more problems than a 1 in (3 cm) scratch on a LaserDisc, but a fingerprint taking up 1% of the area of a DVD would almost certainly cause fewer problems than a similar mark covering 1% of the surface of a LaserDisc.[citation needed]

qas: question: Which format is considered to look most realistic, LaserDisc or DVD?
answers: text: LaserDisc

question: Which format, LaserDisc or DVD, is said to appear sharper and clearer to most viewers?
answers: text: DVDs

question: What features do LaserDiscs lack in, causing DVDs to appear sharper and clearer?
answers: text: video signal-to-noise ratio and bandwidth
context: Similar to the CD versus LP sound quality debates common in the audiophile community, some videophiles argue that LaserDisc maintains a "smoother", more "film-like", natural image while DVD still looks slightly more artificial. Early DVD demo discs often had compression or encoding problems, lending additional support to such claims at the time. However, the video signal-to-noise ratio and bandwidth of LaserDisc are substantially less than that of DVDs, making DVDs appear sharper and clearer to most viewers.

qas: question: What was the vertical blanking interval used for in LaserDiscs, preventing Macrovision signal to be implemented?
answers: text: internal timing

question: Why wasn't there a need to redesign the LaserDisc format to prevent piracy?
answers: text: relatively small market share

question: What protection could not be applied to LaserDiscs, making them prone to piracy?
answers: text: Macrovision's Copyguard protection
context: Another advantage, at least to some consumers, was the lack of any sort of anti-piracy technology. It was claimed that Macrovision's Copyguard protection could not be applied to LaserDisc, due to the format's design. The vertical blanking interval, where the Macrovision signal would be implemented, was also used for the internal timing on LaserDisc players, so test discs with Macrovision would not play at all. There was never a push to redesign the format despite the obvious potential for piracy due to its relatively small market share. The industry simply decided to engineer it into the DVD specification.

qas: question: LaserDisc was the first format to provide what type of releases to consumers?
answers: text: "Special Edition"

question: What was the first "Special Edition" film to be released to home video?
answers: text: the 1984 Criterion Collection edition of Citizen Kane

question: What bonus features were available on the first home video "Special Edition"?
answers: text: interviews, commentary tracks, documentaries, still photographs

question: What feature, unique to LaserDisc, made bonus content possible?
answers: text: support for multiple audio tracks
context: LaserDisc's support for multiple audio tracks allowed for vast supplemental materials to be included on-disc and made it the first available format for "Special Edition" releases; the 1984 Criterion Collection edition of Citizen Kane is generally credited as being the first "Special Edition" release to home video,[citation needed] and for setting the standard by which future SE discs were measured. The disc provided interviews, commentary tracks, documentaries, still photographs, and other features for historians and collectors.

qas: question: What was required of a LaserDisc to continue playback after 60 minutes?
answers: text: a disc has to be flipped over in order to continue watching

question: Which LaserDisc player solves the disc switching dilemma?
answers: text: Pioneer LD-W1

question: What must be reduced in order to allow LaserDisc playback time to increase?
answers: text: line count

question: Which format allows for more playback tie per side, CLV or CAV?
answers: text: CLV
context: The space-consuming analog video signal of a LaserDisc limited playback duration to 30 minutes (CAV) or 60 minutes (CLV) per side because of the hardware manufacturer's refusal to reduce line count for increased playtime. After one side was finished playing, a disc has to be flipped over in order to continue watching a movie, and some titles fill two or more discs. Many players, especially units built after the mid-1980s, can "flip" discs automatically by rotating the optical pickup to the other side of the disc, but this is accompanied by a pause in the movie during the side change. If the movie is longer than what could be stored on two sides of a single disc, manually swapping to a second disc is necessary at some point during the film. One exception to this rule is the Pioneer LD-W1, which features two disc platters. In addition, perfect still frames and random access to individual still frames is limited only to the more expensive CAV discs, which only had a playing time of approximately 30 minutes per side. In later years, Pioneer and other manufacturers overcame this limitation by incorporating a digital memory buffer, which "grabbed" a single frame from a CLV disc.

qas: question: What video problems on a LaserDisc can be caused by dust or scratches?
answers: text: glitches, streaks, bursts of static, or momentary picture interruptions

question: Which format used in DVDs has built-in error correction?
answers: text: digital MPEG-2

question: What type of encoding, analog or digital, causes LaserDiscs to be succeptable to damages?
answers: text: analog
context: The analog information encoded on LaserDiscs does not include any form of built-in checksum or error correction. Because of this, slight dust and scratches on the disc surface can result in read-errors which cause various video quality problems: glitches, streaks, bursts of static, or momentary picture interruptions. In contrast, the digital MPEG-2 format information used on DVDs has built-in error correction which ensures that the signal from a damaged disc will remain identical to that from a perfect disc right up until the point at which damage to the disc surface is so substantial that it prevents the laser from being able to identify usable data.

qas: question: When does "crosstalk" occur?
answers: text: when the laser optical pickup assembly within the player is out of alignment or because the disc is damaged or excessively warped

question: What problem can be caused by a player becoming out of alignment?
answers: text: "crosstalk"

question: How does "crosstalk" appear to the viewer?
answers: text: swirling "barber poles" or rolling lines of static
context: In addition, LaserDisc videos sometimes exhibit a problem known as "crosstalk". The issue can arise when the laser optical pickup assembly within the player is out of alignment or because the disc is damaged or excessively warped, but it could also occur even with a properly functioning player and a factory-new disc, depending on electrical and mechanical alignment problems. In these instances, the issue arose due to the fact that CLV discs require subtle changes in rotating speed at various points during playback. During a change in speed, the optical pickup inside the player might read video information from a track adjacent to the intended one, causing data from the two tracks to "cross"; the extra video information picked up from that second track shows up as distortion in the picture which looks reminiscent of swirling "barber poles" or rolling lines of static.

qas: question: In which format does crosstalk generally not occur?
answers: text: CAV

question: Why does the CAV format prevent crosstalk?
answers: text: the rotational speed never varies

question: What happens during "laser lock"?
answers: text: the player reads the same two fields for a given frame over and over again, causing the picture to look frozen
context: Assuming the player's optical pickup is in proper working order, crosstalk distortion normally does not occur during playback of CAV format LaserDiscs, as the rotational speed never varies. However, if the player calibration is out of order or if the CAV disc is faulty or damaged, other problems affecting tracking accuracy can occur. One such problem is "laser lock", where the player reads the same two fields for a given frame over and over again, causing the picture to look frozen as if the movie were paused.

qas: question: Is LaserDisc quality consistent or inconsistent between player brands? 
answers: text: inconsistency

question: What is LaserDisc playback quality dependent on?
answers: text: hardware quality

question: How cheaply could an older LaserDisc player be purchased in the 1990s?
answers: text: $25

question: What range of prices were high-end LaserDisc players in the 1990s?
answers: text: US$200 to well over $1,000
context: Another significant issue unique to LaserDisc is one involving the inconsistency of playback quality between different makers and models of player. On most televisions, a given DVD player will produce a picture that is visually indistinguishable from other units. Differences in image quality between players only becomes easily apparent on large televisions and substantial leaps in image quality are generally only obtained with expensive, high-end players that allow for post-processing of the MPEG-2 stream during playback. In contrast, LaserDisc playback quality is highly dependent on hardware quality. Major variances in picture quality appear between different makers and models of LD players, even when tested on a low to mid-range television. The obvious benefits of using high quality equipment has helped keep demand for some players high, thus also keeping pricing for those units comparably high. In the 1990s, notable players sold for anywhere from US$200 to well over $1,000, while older and less desirable players could be purchased in working condition for as little as $25.

qas: question: What substandard product was used in LD manufacturing that caused "laser rot"?
answers: text: adhesive

question: What was the internal name for "laser rot" within LD processing plants?
answers: text: "color flash"

question: What problems could occur with laser rot?
answers: text: black spots that looked like mold or burned plastic which cause the disc to skip and the movie to exhibit excessive speckling noise
context: Many early LDs were not manufactured properly; sometimes a substandard adhesive was used to sandwich together the two sides of the disc.[citation needed] The adhesive contained impurities that were able to penetrate the lacquer seal layer and chemically attack the metalized reflective aluminium layer, causing it to oxidize and lose its reflective characteristics. This was a problem that was termed "laser rot" among LD enthusiasts, also called "color flash" internally by LaserDisc-pressing plants. Some forms of laser rot could appear as black spots that looked like mold or burned plastic which cause the disc to skip and the movie to exhibit excessive speckling noise. But, for the most part, rotted discs could actually appear perfectly fine to the naked eye.

qas: question: Why didn't LaserDiscs become popular in North America?
answers: text: high cost of the players and discs

question: By 1990, how many American homes were estimated to use LD?
answers: text: nearly one million

question: Why were LaserDiscs more popular in Japan?
answers: text: prices were kept low to ensure adoption

question: Which format was more popular in high humidity areas such as Singapore?
answers: text: LaserDiscs
context: LaserDisc did not have high market penetration in North America due to the high cost of the players and discs, which were far more expensive than VHS players and tapes, and due to marketplace confusion with the technologically inferior CED, which also went by the name Videodisc. While the format was not widely adopted by North American consumers, it was well received among videophiles due to the superior audio and video quality compared to VHS and Betamax tapes, finding a place in nearly one million American homes by the end of 1990. The format was more popular in Japan than in North America because prices were kept low to ensure adoption, resulting in minimal price differences between VHS tapes and the higher quality LaserDiscs, helping ensure that it quickly became the dominant consumer video format in Japan. Anime collectors in every country the LD format was released, which includes both North America and Japan, also quickly became familiar with this format, and sought the higher video and sound quality of LaserDisc and the availability of numerous titles not available on VHS. LaserDiscs were also popular alternatives to videocassettes among movie enthusiasts in the more affluent regions of South East Asia, such as Singapore, due to their high integration with the Japanese export market and the disc-based media's superior longevity compared to videocassette, especially in the humid conditions endemic to that area of the world.

qas: question: How much did a LD cost in Hong Kong in the 1990s?
answers: text: USD100

question: Broadcast in Hong Kong used which standard formatting?
answers: text: PAL standard

question: In contrast to broadcast, which format did consumers use in Hong Kong?
answers: text: NTSC
context: The format also became quite popular in Hong Kong during the 1990s before the introduction of VCDs and DVD; although people rarely bought the discs (because each LD was priced around USD100), high rental activity helped the video rental business in the city grow larger than it had ever been previously. Due to integration with the Japanese export market, NTSC LaserDiscs were used in the Hong Kong market, in contrast to the PAL standard used for broadcast (This anomaly also exists for DVD). This created a market for multi-system TVs and multi-system VCRs which could display or play both PAL and NTSC materials in addition to SECAM materials (which were never popular in Hong Kong). Some LD players could convert NTSC signals to PAL so that most TVs used in Hong Kong could display the LD materials.

qas: question: By what year had DVD taken over the LaserDisc market?
answers: text: late 1990s

question: Which collector group highly values LaserDisc for their rareness?
answers: text: movie enthusiasts

question: Until the end of what year were movies released in VHS, LD, and DVD in Japan?
answers: text: 2001

question: What country was the only to receive a LD release of Disney's Song of the South?
answers: text: Japan
context: Although the LaserDisc format was supplanted by DVD by the late 1990s, many LD titles are still highly coveted by movie enthusiasts (for example, Disney's Song of the South which is unavailable in the US in any format, but was issued in Japan on LD). This is largely because there are many films that are still only available on LD and many other LD releases contain supplemental material not available on subsequent DVD versions of those films. Until the end of 2001, many titles were released on VHS, LD, and DVD in Japan.

qas: question: In what decade did Philips produce a "professional" LD model for computer?
answers: text: early 1980s

question: In what year were LD jukeboxes created?
answers: text: 1985

question: Who created LD Jukeboxes in 1985?
answers: text: Jasmine Multimedia

question: Which musical artists were featured on LD Jukeboxes in 1985?
answers: text: Michael Jackson, Duran Duran, and Cyndi Lauper
context: In the early 1980s, Philips produced a LaserDisc player model adapted for a computer interface, dubbed "professional". In 1985, Jasmine Multimedia created LaserDisc Juke Boxes featuring music videos from Michael Jackson, Duran Duran, and Cyndi Lauper. When connected to a PC this combination could be used to display images or information for educational or archival purposes, for example thousands of scanned medieval manuscripts. This strange device could be considered a very early equivalent of a CD-ROM.

qas: question: How many EditDroid systems were ever built?
answers: text: 24

question: Were EditDroid discs single or multi-sided?
answers: text: single-sided

question: Which production company engineered the EditDroid machines in the 1980s?
answers: text: Lucasfilm
context: In the mid-1980s Lucasfilm pioneered the EditDroid non-linear editing system for film and television based on computer-controlled LaserDisc players. Instead of printing dailies out on film, processed negatives from the day's shoot would be sent to a mastering plant to be assembled from their 10-minute camera elements into 20-minute film segments. These were then mastered onto single-sided blank LaserDiscs, just as a DVD would be burnt at home today, allowing for much easier selection and preparation of an Edit Decision List. In the days before video assist was available in cinematography, this was the only other way a film crew could see their work. The EDL went to the negative cutter who then cut the camera negative accordingly and assembled the finished film. Only 24 EditDroid systems were ever built, even though the ideas and technology are still in use today. Later EditDroid experiments borrowed from hard-drive technology of having multiple discs on the same spindle and added numerous playback heads and numerous electronics to the basic jukebox design so that any point on each of the discs would be accessible within seconds. This eliminated the need for racks and racks of industrial LaserDisc players since EditDroid discs were only single-sided.

qas: question: In what year did the Doomsday project occur?
answers: text: 1986

question: Which equipment was used for the Doomsday Project?
answers: text: a SCSI-equipped LaserDisc player attached to a BBC Master computer

question: What does LV-ROM stand for?
answers: text: LaserVision Read Only Memory

question: The Doomsday Project discs used which formatting?
answers: text: CAV
context: In 1986, a SCSI-equipped LaserDisc player attached to a BBC Master computer was used for the BBC Domesday Project. The player was referred as an LV-ROM (LaserVision Read Only Memory) as the discs contained the driving software as well as the video frames. The discs used the CAV format, and encoded data as a binary signal represented by the analog audio recording. These discs could contain in each CAV frame video/audio or video/binary data, but not both. "Data" frames would appear blank when played as video. It was typical for each disc to start with the disc catalog (a few blank frames) then the video introduction before the rest of the data. Because the format (based on the ADFS hard disc format) used a starting sector for each file, the data layout effectively skipped over any video frames. If all 54,000 frames are used for data storage an LV-ROM disc can contain 324 MB of data per side. The Domesday Project systems also included a genlock, allowing video frames, clips and audio to be mixed with graphics originated from the BBC Master; this was used to great effect for displaying high resolution photographs and maps, which could then be zoomed into.

qas: question: Which of Apple's programming languages allowed users to ceatively manipulate LaserDiscs?
answers: text: HyperCard

question: What did LaserStacks software enable Mac users to do?
answers: text: play specific content from the disc

question: Where were "stacks" created with the LaserStack software used?
answers: text: in education

question: Which commercial company was LaserStack's most successful distributor?
answers: text: Voyager
context: Apple's HyperCard scripting language provided Macintosh computer users with a means to design databases of slides, animation, video and sounds from LaserDiscs and then to create interfaces for users to play specific content from the disc through software called LaserStacks. User-created "stacks" were shared and were especially popular in education where teacher-generated stacks were used to access discs ranging from art collections to basic biological processes. Commercially available stacks were also popular with the Voyager company being possibly the most successful distributor.

qas: question: A combination computer/LD player was comissioned by what government entity?
answers: text: the U.S. Military

question: How much did Matrox's computer/LD combo weigh?
answers: text: 43 lb (20 kg)

question: How could Matrox's computer unconventionally be controlled?
answers: text: removing the ribbon cable and connecting a serial cable directly from the computer's serial port to the port on the LaserDisc player
context: Under contract from the U.S. Military, Matrox produced a combination computer/LaserDisc player for instructional purposes. The computer was a 286, the LaserDisc player only capable of reading the analog audio tracks. Together they weighed 43 lb (20 kg) and sturdy handles were provided in case two people were required to lift the unit. The computer controlled the player via a 25-pin serial port at the back of the player and a ribbon cable connected to a proprietary port on the motherboard. Many of these were sold as surplus by the military during the 1990s, often without the controller software. Nevertheless, it is possible to control the unit by removing the ribbon cable and connecting a serial cable directly from the computer's serial port to the port on the LaserDisc player.

qas: question: What quality made LDs a consideration for videogames in the 1980s and 1990s?
answers: text: instant-access capability

question: What was the first game to use LaserDiscs?
answers: text: Sega's Astron Belt

question: In what year was Sega's AStron Belt released?
answers: text: 1983
context: The format's instant-access capability made it possible for a new breed of LaserDisc-based video arcade games and several companies saw potential in using LaserDiscs for video games in the 1980s and 1990s, beginning in 1983 with Sega's Astron Belt. American Laser Games and Cinematronics produced elaborate arcade consoles that used the random-access features to create interactive movies such as Dragon's Lair and Space Ace. Similarly, the Pioneer Laseractive and Halcyon were introduced as home video game consoles that used LaserDisc media for their software.

qas: question: With what operating ratio would MUSE Discs operate?
answers: text: 5:3

question: What benefits did the MUSE narrow wavelength red laser have?
answers: text: capable of reading through disc defects such as scratches and even mild disc rot that would cause most other players to stop, stutter or drop-out

question: In addition to scratches and rot, what other common LaserDisc issue was to be eliminated by MUSE discs?
answers: text: Crosstalk

question: How many years did it take Blu-ray and HD-DVD players to duplicate MUSE technology?
answers: text: almost 15 years
context: In 1991, several manufacturers announced specifications for what would become known as MUSE LaserDisc, representing a span of almost 15 years until the feats of this HD analog optical disc system would finally be duplicated digitally by HD DVD and Blu-ray Disc. Encoded using NHK's MUSE "Hi-Vision" analogue TV system, MUSE discs would operate like standard LaserDiscs but would contain high-definition 1,125-line (1,035 visible lines) (Sony HDVS) video with a 5:3 aspect ratio. The MUSE players were also capable of playing standard NTSC format discs and are superior in performance to non-MUSE players even with these NTSC discs. The MUSE-capable players had several noteworthy advantages over standard LaserDisc players, including a red laser with a much narrower wavelength than the lasers found in standard players. The red laser was capable of reading through disc defects such as scratches and even mild disc rot that would cause most other players to stop, stutter or drop-out. Crosstalk was not an issue with MUSE discs, and the narrow wavelength of the laser allowed for the virtual elimination of crosstalk with normal discs.

qas: question: What was the price for early HDTVs?
answers: text: US$10,000

question: Did MUSE have a large or small target market, even in Japan?
answers: text: tiny

question: What were some movies that were released on MUSE LaserDiscs?
answers: text: Terminator 2: Judgment Day, Lawrence of Arabia, A League of Their Own, Bugsy, Close Encounters of the Third Kind, Bram Stoker's Dracula and Chaplin
context: In order to view MUSE encoded discs, it was necessary to have a MUSE decoder in addition to a compatible player. There are televisions with MUSE decoding built-in and set top tuners with decoders that can provide the proper MUSE input. Equipment prices were high, especially for early HDTVs which generally eclipsed US$10,000, and even in Japan the market for MUSE was tiny. Players and discs were never officially sold in North America, although several distributors imported MUSE discs along with other import titles. Terminator 2: Judgment Day, Lawrence of Arabia, A League of Their Own, Bugsy, Close Encounters of the Third Kind, Bram Stoker's Dracula and Chaplin were among the theatrical releases available on MUSE LDs. Several documentaries, including one about Formula One at Japan's Suzuka Circuit were also released.

qas: question: What were "Squeeze LDs"?
answers: text: enhanced 16:9-ratio widescreen LaserDiscs

question: With what aspect ratio did Squeeze LDs operate?
answers: text: 16:9-ratio widescreen

question: Why did Squeeze LDs have a very limited market?
answers: text: very few people owned 16:9 displays

question: Could the 16:9 aspect ratio be easily resized by a normal LD player, or was the image significantly distorted?
answers: text: distorted

question: What percent vertical resolution increase did Squeeze LDs feature over regular widescreen LDs?
answers: text: 33%
context: With the release of 16:9 televisions in the mid-1990s, Pioneer and Toshiba decided that it was time to take advantage of this aspect ratio. Squeeze LDs were enhanced 16:9-ratio widescreen LaserDiscs. During the video transfer stage, the movie was stored in an anamorphic "squeezed" format. The widescreen movie image was stretched to fill the entire video frame with less or none of the video resolution wasted to create letterbox bars. The advantage was a 33% greater vertical resolution compared to letterboxed widescreen LaserDisc. This same procedure was used for anamorphic DVDs, but unlike all DVD players, very few LD players had the ability to unsqueeze the image for 4:3 sets, and very few if any 4:3 sets could be set to play them properly either. If the discs were played on a standard 4:3 television the image would be distorted. Since very few people owned 16:9 displays, the marketability of these special discs was very limited.

qas: question: Which movie was released twice on Squeeze LD?
answers: text: Terminator 2

question: What improvement was added to Terminator 2's second Squeeze LD release?
answers: text: THX certified

question: What Warner Brothers films were available in 16:9 aspect ratio Squeeze LDs?
answers: text: Unforgiven, Grumpy Old Men, The Fugitive, and Free Willy

question: What films were available for Japanese market Squeeze LDs?
answers: text: Basic Instinct, Stargate, Terminator 2: Judgment Day, Showgirls, Cutthroat Island, and Cliffhanger
context: There were no anamorphic LaserDisc titles available in the US except for promotional purposes. Upon purchase of a Toshiba 16:9 television viewers had the option of selecting a number of Warner Bros. 16:9 films. Titles include Unforgiven, Grumpy Old Men, The Fugitive, and Free Willy. The Japanese lineup of titles was different. A series of releases under the banner "SQUEEZE LD" from Pioneer of mostly Carolco titles included Basic Instinct, Stargate, Terminator 2: Judgment Day, Showgirls, Cutthroat Island, and Cliffhanger. Terminator 2 was released twice in Squeeze LD, the second release being THX certified and a notable improvement over the first.

qas: question: What does the acronym RLV stand for?
answers: text: Recordable LaserVision disc

question: Which company originally developed and marketed the RLV?
answers: text: Optical Disc Corporation (ODC, now ODC Nimbus)

question: In what year did ODC develop the Recordable LaserVision Disc?
answers: text: 1984.
context: Another form of recordable LaserDisc that is completely playback-compatible with the LaserDisc format (unlike CRVdisc with its caddy enclosure) is the RLV, or Recordable LaserVision disc. It was developed and first marketed by the Optical Disc Corporation (ODC, now ODC Nimbus) in 1984. RLV discs, like CRVdisc, are also a WORM technology, and function exactly like a CD-R disc. RLV discs look almost exactly like standard LaserDiscs, and can play in any standard LaserDisc player after they have been recorded.

qas: question: What is the difference in appearance between an RLV disc and a regular LD?
answers: text: reflective purple-violet (or blue with some RLV discs) color

question: Why do RLV discs have a blue or purple reflective color?
answers: text: to make it recordable, as opposed to the silver mirror appearance of regular LDs

question: For what purpose were RLVs popular?
answers: text: making short-run quantities of LaserDiscs for specialized applications such as interactive kiosks and flight simulators

question: What color were regular LaserDiscs, in contrast to RLVs blueish purple hues?
answers: text: silver mirror
context: The only cosmetic difference between an RLV disc and a regular factory-pressed LaserDiscs is their reflective purple-violet (or blue with some RLV discs) color resulting from the dye embedded in the reflective layer of the disc to make it recordable, as opposed to the silver mirror appearance of regular LDs. The purplish color of RLVs is very similar to DVD-R and DVD+R discs. RLVs were popular for making short-run quantities of LaserDiscs for specialized applications such as interactive kiosks and flight simulators.

qas: question: In contrast to large LD disks, what is the size of a standard CD?
answers: text: 12 cm (4.7 in)

question: What were CD size "single"-style discs called that were compatible with LaserDisc players?
answers: text: CD Video (CD-V) discs, and Video Single Discs (VSD)

question: How much video content could be stored on a CD-V disk?
answers: text: up to five minutes of analog LaserDisc-type video content

question: What were CD-V's video capacities usually used for?
answers: text: music video

question: Which artist released a music video and three audio tracks on CD-V in 1989?
answers: text: David Bowie
context: There were also 12 cm (4.7 in) (CD size) "single"-style discs produced that were playable on LaserDisc players. These were referred to as CD Video (CD-V) discs, and Video Single Discs (VSD). A CD-V carried up to five minutes of analog LaserDisc-type video content (usually a music video), as well as up to 20 minutes of digital audio CD tracks. The original 1989 release of David Bowie's retrospective Sound + Vision CD box set prominently featured a CD-V video of Ashes to Ashes, and standalone promo CD-Vs featured the video, plus three audio tracks: "John, I'm Only Dancing", "Changes", and "The Supermen".

qas: question: What were VSDs lacking that CD-Vs included?
answers: text: audio CD tracks

question: In what areas of the world were VSDs popular?
answers: text: only in Japan and other parts of Asia

question: Were VSDs or CD-Vs all digital and also playable on DVD players?
answers: text: VSDs
context: CD-Vs are not to be confused with Video CDs (which are all-digital and can only be played on VCD players, DVD players, CD-i players, computers, and later-model LaserDisc players, such as the DVL series from Pioneer that can also play DVDs). CD-Vs can only be played back on LaserDisc players with CD-V capability. VSDs were the same as CD-Vs, but without the audio CD tracks. CD-Vs were somewhat popular for a brief time worldwide, but soon faded from view. VSDs were popular only in Japan and other parts of Asia, and were never fully introduced to the rest of the world.