The Laserdisc (LD) was the first commercial optical disc storage medium, and was used primarily for the presentation of movies. During its development, the format was referred to as the "Optical Videodisc System" before MCA, who owned the patent on the technology, re-named the format Discovision in 1969. They marketed it under that name beginning in late 1978 after the earlier CRV disc format had died out in obscurity. MCA owned the rights to the largest catalog of films in the world during this time, and they directly manufactured and distributed the discs of their movies under the "MCA DiscoVision" label. Pioneer Electronics, who entered the market almost at exactly the time Discovision titles were going on sale in 1978, began manufacturing players and printing discs under the name LaserDisc, by 1981 Laserdisc (without intercaps) had become the common name for the format, and the Discovision label dissappeared, simply becoming MCA or (later) MCA-Universal Laserdisc.
MCA also manufactured discs for other companies, including Paramount, Disney and Warner Brothers. Some of them added their own names onto the disc-jacket in order to signify the movie was not owned by MCA. When MCA folded into Universal several years later, Universal began re-issuing many of the early DiscoVision titles as Universal discs. The DiscoVision versions had largely been avaliable only in pan and scan and had often utilized poor transfers. The Universal versions were largely better. The format has also been known as LV (for "LaserVision", actually a player brand by Philips). The players are also sometimes referred to as VDPs (Video Disc Players).
History
Laserdisc technology was invented by David Paul Gregg in 1958, patented in 1961 and 1969, and first demonstrated by Philips and MCA in 1972. It was available on the market in 1978, two years after the VCR and five years before the CD.
There are more than 1 million players in home use in the US (compared to 85 million VCRs), and more than 4 million in Japan (or 10% of households). LD has been completely replaced by DVD in the North American retail marketplace, as both players and software are no longer produced. Laserdisc 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.
Technical information
Video was stored on LD as an analog signal, while audio could be stored in either analog or digital format and in a variety of surround sound formats. Like on a CD, the surface of the disc is an aluminium foil covered by pits and lands, but whereas on a audio CD (or DVD) the pits and lands will signify binary codes, on an LD the pits are created using frequency modulation of an analog signal.
NTSC discs could carry two analog audio tracks, plus two uncompressed PCM digital audio tracks, which were generally CD quality. PAL discs could carry one pair, either analog or digital. Dolby Digital (also called AC-3) and DTS, which are now common on DVD titles, first became available on Laserdisc. Star Wars: Episode I (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. Other EX codec Laserdiscs include: Fight Club, The Bone Collector, The Haunting, The world is not Enough, End of Days and Austin Powers. Many later discs have no analog audio track, instead offering the choice of a CD-quality PCM audio track (carried directly via the player's optical output) or Dolby Digital. Players could generally convert PCM tracks to analog using an internal digital to analog converter. DTS equipped discs would still be equipped with an analog channel, as DTS uses the space the PCM tracks would normally occupy.
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 and convert it into a 384 kbit/s signal that the decoder could understand. DTS audio took the place of the PCM audio tracks, and required only a direct connection via Optical Audio cable and a decoder to be heard.
Laserdiscs were recorded in one of two formats: CAV (constant angular velocity) or CLV (constant linear velocity). CAV discs were spun at a constant rotational speed during playback, with one video frame read per revolution, whereas CLV discs spun progressively slower as the disc was played from inside edge to outside edge.
A CAV disc holds up to 30 minutes of content per side, while a CLV disc can hold twice that. The main advantage of the CAV format was that its simpler playback method allowed "trick play" features such as freeze frame, slow motion, and reverse on all LD players, while CLV discs required a digital frame buffer to perform the same tasks, which was found only in high-end models. Another advantage was to reduce the visibility of cross talk from adjacent tracks, since on CAV discs this is simply the same point in the next or previous frame. The vast majority of titles were only available in CLV.
Many Laserdisc players manufactured from the late 1980s through the time of the format's death had both composite (red, white and yellow RCA type connectors) and S-Video outputs on the rear panel. When using the S-Video connection, the player would utilize its own internal comb filter, designed to help reduce picture noise, while using the composite outputs forced the player to rely on the comb filter of the display device. Although using the S-Video connection was often considered to yield superior results in the late 80s and early 1990s, most of today's mid and high level television sets contain better comb filters than what the vast majority of players were equipped with. In these instances, where a player is being used with a more modern display, using the composite output and allowing the display device's internal comb filter to do the work often yields better results.
Laserdisc vs. VHS
LD had a number of advantages over VHS. It featured a far sharper picture with 400 vertical lines for NTSC and 440 lines for PAL discs, while VHS only offered 250 lines. PAL LDs come either with analog audio OR digital audio, never both together, while NTSC discs could carry four audio channels (two analog, two digital). This allowed for director's commentary tracks and other features to be added on to a film, giving studios the ability to expand on their releases for "Special Editions". The 1984 Criterion Collection edition of Citizen Kane is generally credited as being the first of the "Special Editions" and for leading the way for the features to be widely used. The level of sound quality was unsurpassed at the time, avaliable on many discs was both a 16bit 44kHz bitstream track, identical to what is found on CD, and a high quality analog audio track. Early Discovision discs lack a digital audio track, but many of those movies received digital sound in later re-issues. Access was random, meaning that one could jump to any point on the disc very quickly (depending on the player and the disc, within a few seconds at the most). This instant seeking allowed a new breed of laserdisc-based video arcade games, beginning with Dragon's Lair, to be born. As LDs were read optically instead of magnetically, a properly-manufactured LD would theoretically last beyond one's lifetime, and as the discs had no moving parts, they were cheaper to manufacture. In addtion, Laserdiscs do not "wear out" or lose quality with each playback as VHS tapes do.
The format was not without its disadvantages. The discs were 30cm (12 inches) across, and were both fragile and heavy. There was no way for home users to record to an LD. Depending on the format, each side of an LD could hold at most 30 or 60 minutes of content, and then the disc would have to be turned over. Most players did this automatically by rotating the optical pickup to the other side of the disc, but except in high-end models with a pre-read buffer, this was accompanied by a pause in the movie of around 10 seconds, and if the movie was longer than two hours, it eventually required putting in a second disc.
In addition, many early laserdiscs were not manufactured properly. Sometimes a substandard adhesive was used to sandwich together the two sides of the disc, causing the disc to delaminate slightly and allowing oxygen to cause the metallic part of the discs to oxidize. This eventually destroyed the disc, a process known as "laser-rot" among LD enthusiasts. Early CDs suffered similar problems, including a notorious batch of defective discs manufactured by Philips-DuPont Optical in Europe during the early 1990s.
Laserdisc vs. DVD
It is interesting to note that the differences between LD technology and DVD have led some videophiles to prefer LD. Laserdiscs use only analog video and almost always carry some form of analog audio. Many purists believe that analog media is capable of higher quality than digital A/V carriers such as CD and DVD. However, this is rarely achieved in practice. Only expertly mastered analog LDs may exhibit this superior quality and even then it requires expensive equipment to realize the benefits.
An advantage to the Laserdisc format over DVD is that video is not digitally-encoded and compressed, and therefore does not experience problems such as artifacting (most visible as blockiness during high motion sequences) or color banding (subtle visible lines in gradient areas, such as skies) that can be caused by the MPEG-2 encoding process as video is prepared for DVD. However, the meticulous frame-by-frame tuning of the encoding process coupled with the variable bit-rate technology generally employed on big-budget DVD releases effectively eliminates this, and an optional feature of the MPEG-2 compression standard allows much higher color resolution to eliminate the visible effect of color banding on some high-end home theatre equipment. Some videophiles will continue to argue that Laserdisc maintains a "smoother" more "film like" image while DVD still looks slightly more artificial. Although this may be true, the generally soft and slightly noisy picture seen with most low and mid-level LD players often turns people off, and the point becomes moot.
A disadvantage with the analog nature of Laserdiscs is that most players exhibit a slight but perceivable 30 Hz video flicker, and slight dust and wear on the hardware or disc can degrade video and audio over time. The DVD format, however, does not introduce any flicker, and the format's digital nature and sophisticated error-correction scheme can often produce spotless video/audio from a DVD, even with dust and scratches on the surface. Laserdisc players also suffered a problem known as "crosstalk". The issue came up when the wide wavelength laser inside the player accidentally picked up picture information from a track adjacent to where it was reading on a disc. The added information usually showed up as distortion in the picture. Some players were better at compensating for and/or avoiding crosstalk entirely than others.
Success of the format
The format was not well-accepted outside of videophile circles in North America, but became more popular in Japan. Part of the reason was marketing. In North America the cost of the players and discs were kept far higher than VHS decks and tapes. In Japan, the LD strategy was very similar to the strategy taken by DVD manufacturers early in its life: prices were kept low to ensure adoption, resulting in minimal price differences between VHS tapes and the higher quality Laserdiscs. LD also quickly became the dominant format of choice amongst Japanese collectors of anime, helping to drive its acceptance.
Nonetheless, the Laserdisc format did not allow for recording onto the discs, while the competing video cassette recorder devices could record using tape cassettes. Combined with the cumbersome disc size and high North American prices for both players and media, the format was doomed to obscurity. When they were first introduced, laser discs were believed to be disruptive technology, a promise they failed to fulfill. Compact Discs and DVDs were to be disruptive instead.
Although the Laserdisc format has been completely supplanted by DVD, and new players are no longer sold outside Japan, many LDs were considered definitive releases of movies and are still highly coveted by movie enthusiasts. Boxed multi-disc LD editions of several films are prized as collector's items. There are many films that are only available on LD. As well, there are various films which are available on DVD as well as LD, but the LD version is preferred for some reason. There are many cases in which the LD version of a particular film due to superior mastering or editing. Thus, many LDs are still very much in demand.
Examples include the anime Five Star Stories, which was only released on LD despite its extreme popularity. Enthusiasts have been known to pay $700 or more for this LD. Likewise, the LD releases of the original Star Wars trilogy are in high demand among fans and videophiles as, out of all home video releases of the pre-"Special Edition" versions of the films, they offer the highest video and audio quality.
It should be noted that the popularity of the LD format in Japan is still great enough that Pioneer continues to manufacture and market two players. The first, the DVL-919, is a DVD/Laserdisc combination unit that was sold for a short while in the U.S. and was subsequently discontinued in 1999 when the format had lost the vast majority of its waning support. In any case, even the least expensive of newer DVD players have generally surpassed the quality and capability of the 919's DVD section and its LD section was never considered better than mediocre by comparison to many other units, even when new. The second of the units offered in Japan, a Laserdisc-only player, model designation CLD-R5, is sold at a lower cost. Although rumor has had it that select Pioneer dealers still have access to leftover, North American specification DVL-919s, and Pioneer has yet to remove the product from their North American website, Pioneer representitives say that the product is offically discontinued and that warranty coverage for 919s will based on the date of manufacturing rather than on the date of sale.
Certain Japanese players, which are considered to be of higher quality or of greater capacity for quality playback than the North American units, are occasionally imported by enthusiasts. These include the LD-S9, HLD-X9 and HLD-X0. All three are manufactured by Pioneer and all three contain technology that was never officially available in North American Laserdisc players. The LD-S9 and HLD-X9 share a highly advanced comb filter, alowing them to offer a considerable advantage in picture quality over most other LD players when the s-video connection is used. The comb filter present in these players is unique and is purportedly the finest comb filter ever used in consumer A/V gear, it is still currently in use in Mitsubishi's top-spec CRT rear projection television sets (the Diamond and now defunct Platinum series sets) and Pioneer's Elite line of rear projection televisions. In addition to the advanced comb filter, the HLD-X9 contains a red laser pickup, which allows for the significant reduction of crosstalk and extremely low picture-noise levels compared to the traditional inafred laser used in most players. As well, the red laser is said to be able to read through all but the worst cases of laser rot and surface wear. The HLD-X9 is, lastly, also a "MUSE" player, capable when properly equipped of plaing back high definition laserdiscs, often called Hi-Vision discs in Japan. Although it lacks the newer high grade comb filter of the previous two players, Pioneer's original MUSE unit, the HLD-X0, is the player of choice for many enthusiasts. It was entirely hand built from hand picked electronics and weighed a massive 36 kilograms. Many argue that the newer X9 was a more capable MUSE player but that the X0 had superior performance with standard NTSC discs.
Laserdisc variations
In 1991, several manufacturers announced specifications for what would become known as "MUSE" Laserdisc. Encoded using technology adopted from "Hi-Vision" (Japanese HDTV) hardware, MUSE discs would operate like standard Laserdiscs but would contain material transferred in High Definition (1080i) widescreen. The MUSE players were also capable of playing standard NTSC format discs and are said to have superior performance to non-MUSE players. The MUSE-capable players had several noteworthy advantages over standard Laserdisc players, incuding 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. In order to view MUSE encoded discs, it was necessary to have a MUSE decoder in addition to a compatible player and an HDTV. Equipment prices were high, especially for early HDTVs which generally eclipsed $10,000 USD, 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, 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 avalible on MUSE. Several documentaries, including one about Formula One at Japan's Suzuka Circuit were also released.
Towards the end of the format's life, a small number of discs were sold in Japan which contained an anamorphic image technology marketed as "squeeze", effectively the same as the 16:9 anamorphic output from a DVD player. Among the very few films available in this format were Terminator 2, Basic Instinct, and Cliffhanger. Unlike MUSE discs, Squeeze titles required a widescreen television set to display the squeezed image correctly, and they ran at standard resolution, offering 400 horizontal lines (they were mainly NTSC, only two PAL "Squeeze" discs were produced). Widescreen sets cost considerably more than a standard set at the time, which played a major part in why the format never caught on.
"LD singles" which are 18 cm (approx. 8", the same size as a 45-RPM record) across rather than the full 30 cm (approx. 12") size, were also published. LD singles only contained a few minutes of video, enough for a music video or two. They are much rarer than the full-size LDs, especially in North America.
Some laser discs, called "picture discs", have artistic etching on one side of the disc to make the disc more visually attractive than the standard shiny silver surface. This etching might look like a movie character, logo, or other promotional material. Sometimes that side of the LD would be made with colored plastic rather than the clear material used for the data side. Picture disc LDs only had video material on one side as the "picture" side could not contain any data. Picture discs are rare in North America.
Pioneer Electronics, one of the format's largest supporters/investors, was also deeply involved in the karaoke business in Japan, and used laserdiscs as the storage medium for music and additional content such as graphics. The format was generally called LD+G. While several other karaoke labels manufactured laserdiscs, there was nothing like the breadth of competition in that industry that exists now, as almost all manufacturers have transitioned to CD+G discs (enroute, possibly, to a new DVD based format).
Another type of video media, CRV Disc, or "Component Recordable Video Disc" were available for a short time, mostly to professionals. CRV discs resemble early PC CD-ROM caddies with a disc inside resembling a full sized LD. CRV discs existed as both pre-recorded releases and also as blank media that could be recorded once (WORM, like CD-R) on each side. CRV was rarely used by the consumer due to the high cost of the equipment and media, and were used largely for backup storage in professional/commercial applications.
External links
Last updated: 10-22-2005 01:56:16
