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Basic Repertoire

Analog Video Formats

Beta, VHS and 8mm

Early analog video tape formats.  The Stereo Hi-Fi versions of these formats can offer excellent sound quality. 

LaserDisc

The laserDisc (LD) was the first commercial optical disc storage medium, and is used primarily for the presentation of movies.

During its development, the format was referred to as the "Reflective Optical Videodisc System" before MCA, who owned the patent on the technology, renamed the format Disco-Vision in 1969. By the time the format was brought to market in 1978, the hyphen had been removed from the format name, and DiscoVision became the official name. Sales of DiscoVision players & discs began on December 15, 1978 starting in Atlanta, Georgia. 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 at almost exactly the time DiscoVision titles were going on sale in 1978, began manufacturing players and printing discs under the name Laser Videodisc. By 1981, Laserdisc (first in CamelCase as LaserDisc, later without the intercap) had become the common name for the format, and the DiscoVision label disappeared, becoming simply 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 available only in pan and scan and had often utilized poor transfers. 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).

Laserdisc technology, using a transparent disc, was invented by David Paul Gregg in 1958 (and patented in 1961 and 1969). By 1969 Philips had developed a videodisc in reflective mode, which has great advantages over the transparent mode. MCA and Philips decided to join their efforts. They first publicly demonstrated the videodisc in 1972. It was first available on the market, in Atlanta, on December 15, 1978, two years after the VHS VCR and five years before the CD, which is based on laserdisc technology. Philips produced the players and MCA the discs. The Philips/MCA cooperation was not successful, and discontinued after a few years.

Software

Resembling a large audio Compact Disc, the standard movie laserdisc was 30 cm in diameter and made up of two single-sided stamped aluminum discs bonded with glue and sandwiched between two sheets of plastic. Laserdisc is an analog format, unlike the modern CD or DVD, which are digital formats. Both formats are pressed with pits and lands making up the structure of the disc. On a digital audio CD (or DVD) the pits and lands will signify binary codes; with a Laserdisc, the pits and lands are created using frequency modulation of an analog signal, with the frequency carrier encoded using pulse-width modulation. Additionally, all laserdiscs could be encoded with chapters akin to tracks and display several modes of time, such as "elapsed", "left in chapter", and "left in side".

Audio

Audio 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 CD quality (2 channels, 16 bit, 44.1KHz sample rate for PAL and 44056Hz for NTSC, and a 96dB signal-to-noise ratio). PAL discs could carry one pair of audio tracks, either analog or digital; in the UK the term LaserVision is used to refer to discs with analog sound, while LaserDisc is used for those with digital audio. Dolby Digital (also called AC-3) and DTS. 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 optical digital audio connection to a DTS decoder.

Many early and lower-end LD players had poor analog audio sections, and many early discs had poor analog audio tracks. The quality of analog audio tracks generally got better as time went on and later discs also applied CX Noise Reduction, which improved the signal-noise ratio of analog audio. In addition many later PAL discs have no analog audio track at all, instead offering the choice of the PCM digital audio track or Dolby Digital.

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 channel to the modulated AC-3 stream. If the player did not have an AC-3 decoder available, the next most attractive option would be the stereo digital tracks. If either the player did not support digital tracks or the disc did not include digital tracks, the only remaining option was to fall back to a monophonic presentation on the analog left track. However, a player that is not aware of AC-3 streams (independent of its ability to decode them) will play the analog audio tracks verbatim, resulting in garbage output in the right channel. With a DTS disc, the PCM digital tracks are not available, so if a DTS decoder was also not available, the only option was to fall back to the stereo analog tracks.

Usually, only one surround sound option existed on a given laserdisc (Dolby Surround, Dolby Digital, or DTS), so if surround sound is desired, the purchaser must carefully match the disc to the player’s capabilities. It should also be noted that both the analog and digital tracks are capable of carrying Dolby Surround-encoded information (whether a particular disc does depends on the manufacturer), and that given a Dolby Surround-encoded source, Laserdisc players and surround-sound processors that implement Dolby Pro Logic are capable of surround output superior to those which only decode Dolby Surround.

Format

Laserdiscs were recorded in one of three formats.

CAV (Constant Angular Velocity) or Standard Play discs supported the several unique features such as freeze frame, variable slow motion and reverse. CAV discs were spun at a constant rotational speed during playback, with one video frame read per revolution and in this mode, 54,000 individual frames or 30 minutes of audio/video could be stored on a single side of a CAV disc. Another unique attribute to CAV was to reduce the visibility of cross talk from adjacent tracks, since on CAV discs any crosstalk at a specific point in a frame is simply from the same point in the next or previous frame. CAV was used less frequently than CLV, reserved for special editions of feature films to highlight bonus material and special effects.

CLV (Constant Linear Velocity) or Extended Play discs do not have the "trick play" features of CAV, offering only simple playback on all but the high-end laserdisc players incorporating a digital frame store. These high-end laserdisc players could add features not normally available to CLV discs such as variable forward and reverse, and a VCR-like "pause". CLV encoded discs could store 60 minutes of audio/video. The vast majority of titles were only available in CLV.

CAA (Constant Angular Acceleration). In the early 1980s, due to problems with crosstalk distortion on CLV extended play LaserDiscs, Pioneer Video introduced CAA formatting for extended play discs. Constant Angular Acceleration is very similar to Constant Linear Velocity save for the fact that CAA varies the angular rotation of the disc in controlled steps instead of gradually slowing down as a CLV disc is read. With exception to 3M/Imation, all LaserDisc manufacturers adopted the CAA encoding scheme, even though many manufacturers still referred CAA extended play discs ubiquitously as CLV on the disc packaging.

Hardware

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 by separating the luminance (brightness) and color parts of the signal, 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 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 a horizontal resolution of 400 lines for NTSC and 440 lines for PAL discs, while VHS only featured 240 lines.

NTSC discs could store multiple audio tracks. This allowed for extras like director's commentary tracks and other features to be added on to 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 (depending on the player and the disc, within a few seconds at the most). By comparison, VHS would require tedious rewinding and fast-forwarding to get to specific points. Laserdiscs were cheaper than videocassettes to manufacture, because they lack the moving parts and plastic outer shell that are necessary for VHS tapes to work. (A standard VHS cassette has at least 14 parts including the actual tape. A Laserdisc has one part, with five or six layers.)

Moreover, because the discs are 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 does not wear the information-bearing part of the discs, and properly manufactured LDs will theoretically last beyond one's lifetime. By contrast, a VHS tape holds all of its picture and sound information on the tape in a magnetic coating which rubs directly against the player heads, causing progressive wear with each use. Also, the tape is thin and delicate, and it is easy for a player mechanism (especially on a low quality model) to mishandle the tape and damage it by creasing it, frilling (stretching) its edges, or even breaking it.

Special Editions

The format's support for multiple audio tracks allowed for vast supplemental materials to be included on-disc and made it the first viable 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, and for setting the standard by which future SE discs were measured. In addition, the format's instant seeking capability made it possible for a new breed of laserdisc-based video arcade games, beginning with Dragon's Lair, to be born.

Disadvantages of the format

Despite the apparent advantages over competing technology at the time (namely VHS), the format was not without its flaws. The discs were 30 cm in diameter, heavy, cumbersome, easier to damage on handling than a VHS cassette, and did not have recording capabilities.

And despite their large physical size, the space-consuming analog video signal of a LaserDisc limited playback duration to 30 or 60 minutes per side. After one side was finished playing, a disc would have to be flipped over in order to continue watching the film, and many films required two discs or more. Many players, especially units built after the mid-1980s, could "flip" discs automatically by rotating the optical pickup to the other side of the disc, but this was accompanied by a pause in the movie during the side change. If the movie was longer than what could be stored on 2 sides of a single disc, manually swapping to a second disc would be necessary at some point during the film.

LaserRot

To make matters worse, many early LDs were not manufactured properly; sometimes a substandard adhesive was used to sandwich together the two sides of the disc. The adhesive contained impurities that were able to penetrate the lacquer seal layer and chemically attack the reflective substrate, causing it to oxidize and lose its reflective characteristics. This was a problem that was coined "laser rot" (or, "LaserRot", after the original official CamelCase "LaserDisc" name of the underlying product) 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

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. Some claim that analog media are capable of higher quality than digital A/V carriers such as CD and DVD, and early DVD demo discs often had compression or encoding problems, giving LD proponents fuel for the fire. However, "LD-perfection" is rarely achieved in practice. Only the absolute best LDs, few and far between, exhibit such superior quality in comparison to the newer DVDs, and even then, expensive equipment is required 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 macroblocking (most visible as blockiness during high motion sequences) or contrast banding (subtle visible lines in gradient areas, such as skies or light casts from spotlights) that can be caused by the MPEG-2 encoding process as video is prepared for DVD. Fortunately, 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.

A disadvantage with the analog nature of Laserdiscs is that most players exhibit a slight but perceivable 25 or 30 Hz video flicker. Slight dust and scratches could cause various problems that could affect video quality and possibly also tracking accuracy of the disc by the player. Wearout and/or calibration drift on the hardware could also play a role in degrading video quality, audio quality, and tracking accuracy. The DVD format, however, does not introduce any flicker if played on progressive scan equipment, 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 to a certain extent.

Laserdisc players sometimes suffered a problem known as "crosstalk" on extended play discs, usually with equipment requiring service of the laser optical pickup assembly when this occurs. However, the problem with crosstalk may also occur with poorly manufactured CLV Laserdiscs or with discs that are excessively warped. The issue came up when the optical pickup inside the player accidentally picked up the encoded video information from a track adjacent to where it was reading on the disc. The added information usually showed up as distortion in the picture, usually looking reminiscent of and referred to as "barber poles". Some players were better at compensating for and/or avoiding crosstalk entirely than others, provided that the cause of crosstalk was the disc and not the player. However, there is no crosstalk distortion on CAV standard play LaserDiscs as the rotational speed never varies. But, if the player calibration is out of order or if the CAV disc is faulty, other problems affecting tracking accuracy could occur, such as "laser lock", a problem where the player reads the same track and, thus, the same two fields for one frame over and over again, causing the picture to freeze as if in pause.

Laserdisc is a composite video format: the luminance (black and white) and chrominance (color) information are transmitted in one signal and it is the responsibility of the receiver to separate them. While good comb filters can do a decent job at it, these two signals cannot be completely separated. On DVDs the signals are stored separately, which results in higher fidelity particularly at strong color borders or places with lots of detail, particularly if there is moderate movement in the picture. However, this also applies to low-contrast details like skin tones, where comb filters almost inevitably smudge some detail.

DVDs inherent image resolution is also greater than Laserdisc. Most DVD players allow an anamorphic transfer of a 16:9 movie to be downconverted into letterbox or pan & scan for TVs that don't support anamorphic display, while very few LD players supported this feature, necessitating the issue of separate editions.

Another major advantage to DVD over Laserdisc was the fact that LD playback quality was highly dependent on player quality (as with any analog format). On most television sets, a given DVD player will produce a picture that is visually indistinguishable from other units; quality differences between players only become easily apparent with higher-end equipment. This was not true of Laserdisc playback quality. Major variances in picture quality could appear between different makes and models of LD player, even when tested on a TV that was not particularly high-end. This fact has had long lasting ramifications, as the pricing for what were considered to be good players has remained comparably high (anywhere from $200 to well over $1,000), while older and less desirable players can be purchased in working condition for as little as $25.

Success of the format

The format was not well received 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 was kept far higher than VHS decks and tapes (mainly to combat anticipated losses at the box office). 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. Also in Hong Kong, although the retail prices of laserdiscs were relatively high, they became quite popular in the city during the 1990s before the introduction of VCDs and DVDs. The reason was people rarely bought the discs; they usually rented them and the video renting business grew larger than ever at that time.

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 inconvenient disc size and high North American prices for both players and media, the format was doomed to obscurity. When they were first introduced, LaserDiscs were believed to be what would later be referred to as 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 are still highly coveted by movie enthusiasts. 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. As well, there are various films that are available on DVD as well as LD, but the LD version is preferred.

MUSE LD

In 1991, several manufacturers announced specifications for what would become known as MUSE Laserdisc. Encoded using NHK's MUSE "Hi-Vision" analogue TV system, MUSE discs would operate like standard Laserdiscs but would contain high-definition 1125-line (1035 visible lines) video with a 5:3 aspect ratio. 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, 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. In order to view MUSE encoded discs, it was necessary to have a MUSE decoder in addition to a compatible player and a MUSE-compatible TV set. 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: 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.

Laserdisc Sizes

The most common size of Laserdisc was 30cm (12 inches). These approximated the size of LP vinyl records. These discs allowed for 30 minutes per side (CAV) or 60 minutes per side (CLV). The vast majority of programming for the Laserdisc format was produced on these discs.

18 cm Laserdiscs were also published. These were approx. 8 inches; one inch larger in diameter than a standard 45-RPM record. These "EP"-sized LDs allowed for 20 minutes per side (CLV). They are much rarer than the full-size LDs, especially in North America. These discs were often used for music video compilations.

There were also 12cm (5 inch, same as an audio CD) "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 5 minutes of analog laserdisc-type video content (usually a music video), as well as up to 20 minutes of digital audio CD tracks. 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 really introduced to the rest of the world.