Blu-ray or Blu-ray Disc is a digital optical disc data storage format. It was designed to supersede the DVD format, is capable of storing several hours of video in high-definition and ultra high-definition resolution; the main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, Xbox One. The name "Blu-ray" refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs; the plastic disc is 120 millimetres in diameter and 1.2 millimetres thick, the same size as DVDs and CDs. Conventional or pre-BD-XL Blu-ray discs contain 25 GB per layer, with dual-layer discs being the industry standard for feature-length video discs. Triple-layer discs and quadruple-layer discs are available for BD-XL re-writer drives. High-definition video may be stored on Blu-ray discs with up to 2160p resolution and at up to 60 frames per second.
DVD-Video discs were limited to a maximum resolution of 576p. Besides these hardware specifications, Blu-ray is associated with a set of multimedia formats; the BD format was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, motion pictures. Sony unveiled the first Blu-ray disc prototypes in October 2000, the first prototype player was released in April 2003 in Japan. Afterwards, it continued to be developed until its official release on June 20, 2006, beginning the high-definition optical disc format war, where Blu-ray Disc competed with the HD DVD format. Toshiba, the main company supporting HD DVD, conceded in February 2008, released its own Blu-ray Disc player in late 2009. According to Media Research, high-definition software sales in the United States were slower in the first two years than DVD software sales. Blu-ray faces competition from the continued sale of DVDs. Notably, as of January 2016, 44% of U. S. broadband. The information density of the DVD format was limited by the wavelength of the laser diodes used.
Following protracted development, blue laser diodes operating at 405 nanometers became available on a production basis, allowing for development of a more-dense storage format that could hold higher-definition media. Sony started two projects in collaboration with Panasonic, TDK, applying the new diodes: UDO, DVR Blue, a format of rewritable discs that would become Blu-ray Disc; the core technologies of the formats are similar. The first DVR Blue prototypes were unveiled at the CEATEC exhibition in October 2000 by Sony. A trademark for the "Blue Disc" logo was filed February 9, 2001. On February 19, 2002, the project was announced as Blu-ray Disc, Blu-ray Disc Founders was founded by the nine initial members; the first consumer device arrived in stores on April 10, 2003: the Sony BDZ-S77, a US$3,800 BD-RE recorder, made available only in Japan. But there was no standard for prerecorded video, no movies were released for this player. Hollywood studios insisted that players be equipped with digital rights management before they would release movies for the new format, they wanted a new DRM system that would be more secure than the failed Content Scramble System used on DVDs.
On October 4, 2004, the name "Blu-ray Disc Founders" was changed to the Blu-ray Disc Association, 20th Century Fox joined the BDA's Board of Directors. The Blu-ray Disc physical specifications were completed in 2004. In January 2005, TDK announced that they had now developed an ultra-hard yet thin polymer coating for Blu-ray discs. Cartridges used for scratch protection, were no longer necessary and were scrapped; the BD-ROM specifications were finalized in early 2006. AACS LA, a consortium founded in 2004, had been developing the DRM platform that could be used to securely distribute movies to consumers. However, the final AACS standard was delayed, delayed again when an important member of the Blu-ray Disc group voiced concerns. At the request of the initial hardware manufacturers, including Toshiba and Samsung, an interim standard was published that did not include some features, such as managed copy; the first BD-ROM players were shipped in mid-June 2006, though HD DVD players beat them to market by a few months.
The first Blu-ray Disc titles were released on June 20, 2006: 50 First Dates, The Fifth Element, House of Flying Daggers, Underworld: Evolution, xXx, MGM's The Terminator. The earliest releases used the same method used on standard DVDs; the first releases using the newer VC-1 and AVC formats were introduced in September 2006. The first movies using 50 GB dual-layer discs were introduced in October 2006; the first audio-only albums were released in May 2008. The first mass-market Blu-ray Disc rewritable drive for the PC was the BWU-100A, released by Sony on July 18, 2006, it recorded both single and dual-layer BD-Rs as well as BD-REs and had a suggested retail price of US $699. As of June 2008, more than 2,500 Blu-ray Disc titles were available in Australia
In January 2004, Sony announced the Hi-MD media storage format as a further development of the MiniDisc format. With its release in 2004, came the ability to use newly developed, high-capacity 1 gigabyte Hi-MD discs, sporting the same dimensions as regular MiniDiscs; the Hi-MD format can be considered obsolete as the last recorder/player was discontinued in 2011. The discs themselves were withdrawn from sale in September 2012, though regular MiniDiscs are still available; the ability to save non-audio data such as documents and pictures Longer playback and recording times per disc The ability to record in linear PCM, offering CD-quality audio. This eliminates compression artifacts that occur when recording directly to lossy audio formats such as Sony's ATRAC, or other formats like MP3, AAC, Windows Media Audio; the introduction of a new ATRAC3plus codec with new Hi-LP and Hi-SP bitrates Compatibility with standard MiniDiscsHi-MD offers the choice of several codecs for audio recording: PCM, Hi-SP and Hi-LP, each selectable on the Hi-MD Walkman itself.
PCM is the highest quality mode, followed by Hi-SP Hi-LP. PCM mode allows 94 minutes of lossless CD-quality audio to be recorded to a 1 GB Hi-MD disc. Hi-SP allows seven hours and fifty-five minutes of audio to be recorded on a 1 GB Hi-MD. Hi-LP allows 34 hours on a 1 GB Hi-MD; each of these codecs is available natively for recording on standalone Hi-MD devices. Additional bitrates are available with SonicStage software on the computer. Up to 45 hours of audio can be recorded per disc at the lowest-quality setting via SonicStage PC transfer. All Hi-MD units have the ability to play back regular MiniDiscs. Most Hi-MD Walkmans have the capability to record standard MiniDiscs in standard SP, LP2 and LP4 codecs in MD mode, ideal for creating discs intended to be played back in older MiniDisc units. Hi-MD discs offer the ability to store computer files in addition to audio data. For example, a Hi-MD disc could have both school or work documents, videos, etc. as well as music if desired. When connected to a computer, a Hi-MD Walkman is seen as standard USB Mass Storage device, just like a USB stick or external hard drive.
On a Windows computer, a Hi-MD device is listed as "Removable Disk" in "My Computer". The disc has a FAT filesystem. Hi-MD units are powered by the USB bus when connected—just like USB flash drives, they do not require additional power when plugged into a computer. Sony's SonicStage music management software is not needed to manipulate files on the discs. However, when SonicStage software is active, the recorder is not treated as a data storage device—SonicStage "takes over" the management of the device; this is necessary. Among these are some for reading/writing DRM-data, setting/getting the date on the device, erasing/formatting of the disc, control of audio-playback and reading defect-lists; when connected to a PC, "PC--MD" appears on the Hi-MD device's display to indicate the unit is connected in PC—MD mode. In PC—MD mode, pressing Play on the unit, for example, results in "PC--MD" flashing, indicating this function cannot be activated from the device when connected to the computer, it is a slave to the computer in this mode.
PC—MD status is constant as long as the unit is connected via USB cable. To play back Hi-MD audio data on the PC, SonicStage is needed, it can be done in two ways: Launch SonicStage. Play audio from Hi-MD inside SonicStage; the audio is played back on the computer's PC speakers. SonicStage reads the audio data straight from the Hi-MD disc. Transfer the audio data to the PC in SonicStage. Play the audio back from the PC's hard drive. Once the operation of transferring audio with SonicStage is completed, the audio itself can be saved in any number of ways. Saving audio in SonicStage in standard WAV format is a accepted way to get the audio into many third-party applications like editors and sound analyzers; the user can proceed to record CDs, edit the audio, archive to format of choice, etc. Hi-MD units can play back standard MiniDiscs recorded in non-Hi-MD units, in addition to record on standard MiniDiscs and higher-capacity 1 GB Hi-MD discs. There are two user-selectable operational modes on Hi-MD units: Hi-MD mode.
These are automatically selected. However, when a blank disc is inserted, the recorder will default to the user-selectable Disc Mode for any recordings made on it; the default Disc Mode on Hi-MD devices is Hi-MD mode. MD mode is useful when intending to record on a standard MiniDisc using standard MD codecs for playback on devices that are not Hi-MD compatible. Data storage cannot be used in MD mode. Hi-MD mode is useful when the benefits of Hi-MD mode are to be used, such as increased capacity on standard MiniDiscs, new codec choices and the ability to save da
GD-ROM is a proprietary optical disc format used for the Dreamcast video game console, as well as its arcade counterpart, the Sega NAOMI and select Triforce arcade board titles. Developed by Yamaha, Sega intended to use the format to curb piracy common to standard compact discs and to offer increased storage capacity, it is similar to the standard CD-ROM except that the pits on the disc are packed more together, resulting in a higher storage capacity of 1 gigabyte, a 42% increase over a conventional CD's capacity of 700 megabytes. The Dreamcast ended up being the only sixth-generation console with a disc based on CD technology rather than DVD technology. In addition, it proved to be an ineffective anti-piracy measure when it was discovered the Dreamcast's forgotten Mil-CD functionality could be exploited to boot full games burned to CD. After the discontinuation of the Dreamcast worldwide on March 31, 2001, Sega continued to use the GD-ROM format in arcades with the Sega NAOMI 2, Triforce and Sega Chihiro.
With the release of the Sega Lindbergh in 2005, Sega moved on to DVD discs and continued to use satellite and internet technology in the arcade. The last disc-based Naomi 2 and Triforce games were released in 2006 and nothing has been released in the GD-ROM format in the following years; the format was developed for Sega by Yamaha, first commercially appeared with the Dreamcast's Japanese launch in November 1998. GD-ROM was created because the standard CD-ROM was prone to piracy and reaching the limits of its storage capacity, while implementing the brand-new DVD-ROM technology would have made console production too costly. In addition, the Dreamcast did retain the ability to read standard CD-ROM discs, thus still suffered from software piracy as bootleggers managed to fit certain games on CDs and exploit the Dreamcast console's compatibility with the MIL-CD format. Before the Dreamcast was released, Sega "confirmed that Dreamcast owners will one day be able to upgrade the GD-ROM drive to DVD," as information indicated Sony's upcoming PlayStation 2 would use the DVD format with its much larger capacity 4.7 GB single-layered up to 8.5 GB double-layered discs compared to the 1 GB capacity of the GD-ROM.
Despite displaying a Dreamcast DVD display unit at E3 2000, the plans for a DVD add-on or separate unit never materialized during the short production run of the Dreamcast. GD-ROM was made available as an upgrade for the Dreamcast's arcade cousin, Sega NAOMI and the Sega NAOMI 2, providing alternate media to its cartridge-based software, it is used as an option on both the Sega Chihiro and Triforce. There are three data areas on a GD-ROM disc; the first is in conventional CD format, contains an audio track with a warning that the disc is for use on a Dreamcast, can damage CD players. These vary by region; the CD section contains a data segment, only readable in PCs. Although most discs include only text files identifying the game, its copyright and bibliography, some contain bonus material for home computer users. There follows a separator track which contains no data except for the text Produced by or under license from Sega Enterprises LTD Trademark Sega; the final section of the disc contains the game data itself in a higher density format.
This section is 112 minutes long, with a data size of 1.0 GB. A normal CD-reader will not read beyond the first track because, according to the CD table of contents, there is no data there. With modified firmware on a few optical drive models that looks for a second TOC in the high-density region it is possible to read data from the high-density region. One can utilize a "swap-trick" by first letting the CD-reader read the TOC from an audio CD with a special 99 minute TOC and swapping that disc with a GD-ROM in a way that avoids alerting the CD-reader that a new disc has been inserted, it is possible to read as much data from the high-density region as indicated by the TOC from the first disc. The most popular way to access data from GD-ROMs, however, is to use the Dreamcast itself as a drive, copy the data to a computer by means of a "coder's cable" or a Dreamcast Broadband Adapter. Another alternative is modding the Dreamcast to add a USB connector. Sega has discontinued production of GD-ROM media.
The first section contains a message informing users that the disc can damage AV equipment. Different discs varying by region, contain different messages. NTSC-U discs contain this message: "Warning! This disc is only for use on Sega Dreamcast." Or this message: "This is a Dreamcast game disc, the first track contains game data, please do not play it on a normal CD Player." Some discs contain humorous messages from the game's characters. This is common on Japanese NTSC-J discs. PAL region discs contain this message: "This is a Dreamcast disc and is for use only on a Dreamcast unit. Playing this disc on a Hi-Fi or other audio equipment can cause serious damage to its speakers. Please stop this disc now." The message is repeated in French, German and Italian. Some PAL region games however; the GD-ROM in the Dreamcast works in constant angular velocity mode, like the majority of modern optical drives. Old CD-ROM drives r
DVD is a digital optical disc storage format invented and developed in 1995. The medium can store any kind of digital data and is used for software and other computer files as well as video programs watched using DVD players. DVDs offer higher storage capacity than compact discs. Prerecorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD; such discs are a form of DVD-ROM because data can only be not written or erased. Blank recordable DVD discs can be recorded once using a DVD recorder and function as a DVD-ROM. Rewritable DVDs can be erased many times. DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format as well as for authoring DVD discs written in a special AVCHD format to hold high definition material. DVDs containing other types of information may be referred to as DVD data discs; the Oxford English Dictionary comments that, "In 1995 rival manufacturers of the product named digital video disc agreed that, in order to emphasize the flexibility of the format for multimedia applications, the preferred abbreviation DVD would be understood to denote digital versatile disc."
The OED states that in 1995, "The companies said the official name of the format will be DVD. Toshiba had been using the name ‘digital video disc’, but, switched to ‘digital versatile disc’ after computer companies complained that it left out their applications.""Digital versatile disc" is the explanation provided in a DVD Forum Primer from 2000 and in the DVD Forum's mission statement. There were several formats developed for recording video on optical discs before the DVD. Optical recording technology was invented by David Paul Gregg and James Russell in 1958 and first patented in 1961. A consumer optical disc data format known as LaserDisc was developed in the United States, first came to market in Atlanta, Georgia in 1978, it used much larger discs than the formats. Due to the high cost of players and discs, consumer adoption of LaserDisc was low in both North America and Europe, was not used anywhere outside Japan and the more affluent areas of Southeast Asia, such as Hong-Kong, Singapore and Taiwan.
CD Video released in 1987 used analog video encoding on optical discs matching the established standard 120 mm size of audio CDs. Video CD became one of the first formats for distributing digitally encoded films in this format, in 1993. In the same year, two new optical disc storage formats were being developed. One was the Multimedia Compact Disc, backed by Philips and Sony, the other was the Super Density disc, supported by Toshiba, Time Warner, Matsushita Electric, Mitsubishi Electric, Thomson, JVC. By the time of the press launches for both formats in January 1995, the MMCD nomenclature had been dropped, Philips and Sony were referring to their format as Digital Video Disc. Representatives from the SD camp asked IBM for advice on the file system to use for their disc, sought support for their format for storing computer data. Alan E. Bell, a researcher from IBM's Almaden Research Center, got that request, learned of the MMCD development project. Wary of being caught in a repeat of the costly videotape format war between VHS and Betamax in the 1980s, he convened a group of computer industry experts, including representatives from Apple, Sun Microsystems and many others.
This group was referred to as the Technical Working Group, or TWG. On August 14, 1995, an ad hoc group formed from five computer companies issued a press release stating that they would only accept a single format; the TWG voted to boycott both formats unless the two camps agreed on a converged standard. They recruited president of IBM, to pressure the executives of the warring factions. In one significant compromise, the MMCD and SD groups agreed to adopt proposal SD 9, which specified that both layers of the dual-layered disc be read from the same side—instead of proposal SD 10, which would have created a two-sided disc that users would have to turn over; as a result, the DVD specification provided a storage capacity of 4.7 GB for a single-layered, single-sided disc and 8.5 GB for a dual-layered, single-sided disc. The DVD specification ended up similar to Toshiba and Matsushita's Super Density Disc, except for the dual-layer option and EFMPlus modulation designed by Kees Schouhamer Immink.
Philips and Sony decided that it was in their best interests to end the format war, agreed to unify with companies backing the Super Density Disc to release a single format, with technologies from both. After other compromises between MMCD and SD, the computer companies through TWG won the day, a single format was agreed upon; the TWG collaborated with the Optical Storage Technology Association on the use of their implementation of the ISO-13346 file system for use on the new DVDs. Movie and home entertainment distributors adopted the DVD format to replace the ubiquitous VHS tape as the primary consumer digital video distribution format, they embraced DVD as it produced higher quality video and sound, provided superior data lifespan, could be interactive. Interactivity on LaserDiscs had proven desirable to consumers collectors; when LaserDisc prices dropped from $100 per
Compact disc is a digital optical disc data storage format, co-developed by Philips and Sony and released in 1982. The format was developed to store and play only sound recordings but was adapted for storage of data. Several other formats were further derived from these, including write-once audio and data storage, rewritable media, Video Compact Disc, Super Video Compact Disc, Photo CD, PictureCD, CD-i, Enhanced Music CD; the first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan. Standard CDs have a diameter of 120 millimetres and can hold up to about 80 minutes of uncompressed audio or about 700 MiB of data; the Mini CD has various diameters ranging from 60 to 80 millimetres. At the time of the technology's introduction in 1982, a CD could store much more data than a personal computer hard drive, which would hold 10 MB. By 2010, hard drives offered as much storage space as a thousand CDs, while their prices had plummeted to commodity level. In 2004, worldwide sales of audio CDs, CD-ROMs and CD-Rs reached about 30 billion discs.
By 2007, 200 billion CDs had been sold worldwide. From the early 2000s CDs were being replaced by other forms of digital storage and distribution, with the result that by 2010 the number of audio CDs being sold in the U. S. had dropped about 50% from their peak. In 2014, revenues from digital music services matched those from physical format sales for the first time. American inventor James T. Russell has been credited with inventing the first system to record digital information on an optical transparent foil, lit from behind by a high-power halogen lamp. Russell's patent application was filed in 1966, he was granted a patent in 1970. Following litigation and Philips licensed Russell's patents in the 1980s; the compact disc is an evolution of LaserDisc technology, where a focused laser beam is used that enables the high information density required for high-quality digital audio signals. Prototypes were developed by Sony independently in the late 1970s. Although dismissed by Philips Research management as a trivial pursuit, the CD became the primary focus for Philips as the LaserDisc format struggled.
In 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. After a year of experimentation and discussion, the Red Book CD-DA standard was published in 1980. After their commercial release in 1982, compact discs and their players were popular. Despite costing up to $1,000, over 400,000 CD players were sold in the United States between 1983 and 1984. By 1988, CD sales in the United States surpassed those of vinyl LPs, by 1992 CD sales surpassed those of prerecorded music cassette tapes; the success of the compact disc has been credited to the cooperation between Philips and Sony, which together agreed upon and developed compatible hardware. The unified design of the compact disc allowed consumers to purchase any disc or player from any company, allowed the CD to dominate the at-home music market unchallenged. In 1974, Lou Ottens, director of the audio division of Philips, started a small group with the aim to develop an analog optical audio disc with a diameter of 20 cm and a sound quality superior to that of the vinyl record.
However, due to the unsatisfactory performance of the analog format, two Philips research engineers recommended a digital format in March 1974. In 1977, Philips established a laboratory with the mission of creating a digital audio disc; the diameter of Philips's prototype compact disc was set at 11.5 cm, the diagonal of an audio cassette. Heitaro Nakajima, who developed an early digital audio recorder within Japan's national public broadcasting organization NHK in 1970, became general manager of Sony's audio department in 1971, his team developed a digital PCM adaptor audio tape recorder using a Betamax video recorder in 1973. After this, in 1974 the leap to storing digital audio on an optical disc was made. Sony first publicly demonstrated an optical digital audio disc in September 1976. A year in September 1977, Sony showed the press a 30 cm disc that could play 60 minutes of digital audio using MFM modulation. In September 1978, the company demonstrated an optical digital audio disc with a 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, cross-interleaved error correction code—specifications similar to those settled upon for the standard compact disc format in 1980.
Technical details of Sony's digital audio disc were presented during the 62nd AES Convention, held on 13–16 March 1979, in Brussels. Sony's AES technical paper was published on 1 March 1979. A week on 8 March, Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc" in Eindhoven, Netherlands. Sony executive Norio Ohga CEO and chairman of Sony, Heitaro Nakajima were convinced of the format's commercial potential and pushed further development despite widespread skepticism; as a result, in 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. Led by engineers Kees Schouhamer Immink and Toshitada Doi, the research pushed forward laser and optical disc technology. After a year of experimentation and discussion, the task force produced the Red Book CD-DA standard. First published in 1980, the stand
Nintendo optical discs
Nintendo optical discs are the optical disc format used to distribute video games released by Nintendo. This includes the GameCube Game Disc, Wii Optical Disc, Wii U Optical Disc; the physical size of a GameCube Game Disc is that of a miniDVD, the Wii and Wii U Optical Discs are the size of a DVD. GameCube discs can be used with the original version of the Wii and Wii Optical Discs can be used in the Wii U for backward compatibility. A burst cutting area is located at the inner ring of the disc surface. In 2017, Nintendo dropped the disc-based media in favor of game cards for the Wii U's successor, the Nintendo Switch; the GameCube Game Disc is the game medium for the GameCube, created by Panasonic, extended for use on the Wii through backward compatibility. The GameCube Game Disc is a 1.5 GB, 8 cm miniDVD based technology which reads at a constant angular velocity. It was chosen by Nintendo to prevent copyright infringement of its games, to reduce cost and by avoiding licensing fees to the DVD Forum.
This prevents the consoles from being used as general DVD players. One downside to the GameCube Game Disc is the small amount of storage they provide; as a result, some games with large amounts of data needed to be placed across two discs, such as Resident Evil 4 and Enter the Matrix. Multi-platform games that fit on PlayStation 2 and Xbox DVD discs saw the removal of certain features in order to fit on GameCube Game Discs. Full-motion video scenes and audio are more compressed to fit on a single disc, reducing their quality. Prior to the GameCube, Nintendo consoles traditionally used cartridge-based media; the Wii Optical Disc is the physical game medium for the Wii, created by Panasonic. Nintendo extended their proprietary technology to use a full size 12 cm, 4.7/8.54 GB DVD-based disc, enabling it to have the benefits of the GameCube Game Disc, while having the standard capacity of a double-layer DVD-ROM. Although the Wii can use double-layer discs, all titles were single-layer prior to the release of Super Smash Bros.
Brawl. With the release of Super Smash Bros. Brawl, Nintendo admitted that some Wii systems may have trouble reading dual-layer discs due to a dirty laser lens. Nintendo repaired systems with dual-layer problems, released a disc cleaning kit for users to purchase; the Wii U Optical Disc is the physical game medium for the Wii U, with a capacity of 25 GB. The Wii U system is backward compatible with Wii Optical Discs, but not backward compatible with GameCube game discs; the optical discs used for the Wii U differ in appearance from most other optical discs in that they have soft, rounded edges. The format was developed and supplied by Panasonic, one of the major patent holders in Blu-ray technology, it is not clear whether the Wii U Optical Disc is similar in physical design to the Blu-ray physical disc specification. Former Nintendo president Satoru Iwata stated, "Wii U does not have DVD or Blu-ray playback capabilities; the reason for, that we feel that enough people have devices that are capable of playing DVDs and Blu-ray, such that it didn't warrant the cost involved to build that functionality into the Wii U console because of the patents related to those technologies", as, like with the GameCube and Wii optical discs, was chosen by Nintendo to prevent copyright infringement of its games, to reduce cost by avoiding licensing fees to the Blu-ray Disc Association and to reduce loading times.
This prevents the console from being used as general Blu-ray players. Each Nintendo optical disc contains a burst cutting area mark, a type of barcode, written to the disc with a YAG laser; the data stored in this BCA mark includes an encrypted table related to the hardware-based copy-protection mechanics, in addition to 64 bytes of un-encrypted user-accessible data. A BCA mark is visible to the naked eye, it should not be confused with the IFPI mark, on all optical discs. BCA is described in Annex K of the physical specification, can be seen between radius 22.3±0.4 mm and 23.5±0.5 mm. There are six additional evenly spaced small cuts just outside the BCA radius, which are related to the copy-protection used; these small cuts can be seen if the disc is held in front of a strong light source. GD-ROM Black Book Description of authentication method
Video CD is a home video format and the first format for distributing films on standard 120 mm optical discs. The format was adopted in Southeast Asia and superseded the VHS and Betamax systems in the region until DVD became affordable in the region in the late 2000s; the format is a standard digital format for storing video on a compact disc. VCDs are playable in dedicated VCD players and playable in most DVD players, personal computers and some video game consoles. However, they are less playable in some Blu-ray Disc players and video game consoles such as the Sony PlayStation 3/4 due to lack of support for backward compatibility of the older MPEG-1 format; the Video CD standard was created in 1993 by Sony, Matsushita, JVC and is referred to as the White Book standard. Although they have been superseded by other media, VCDs continue to be retailed as a low-cost video format. LaserDisc was first available on the market, in Atlanta, Georgia, on December 15, 1978; this 30 cm disc could hold an hour of analog video on each side.
The Laserdisc provided picture quality nearly double that of VHS tape and analog audio quality far superior to VHS. Philips teamed up with Sony to develop a new type of disc, the compact disc or CD. Introduced in 1982 in Japan, the CD is about 120 mm in diameter, is single-sided; the format was designed to store digitized sound and proved to be a success in the music industry. A few years Philips decided to give CDs the ability to produce video, utilizing the same technology as its LaserDisc counterpart; this led to the creation of CD Video in 1987. However, the disc's small size impeded the ability to store analog video. Therefore, CD-V distribution was limited to featuring music videos, it was soon discontinued by 1991. By the early 1990s engineers were able to digitize and compress video signals improving storage efficiency; because this new format could hold 74/80 minutes of audio and video on a 650/700MB disc, releasing movies on compact discs became a reality. Extra capacity was obtained by sacrificing the error correction.
This format was named Video CD or VCD. VCD enjoyed a brief period of success, with a few major feature films being released in the format; however the introduction of the CD-R disc and associated recorders stopped the release of feature films in their tracks because the VCD format had no means of preventing unauthorized copies from being made. However, VCDs are still being released in several countries in Asia, but now with copy-protection; the development of more sophisticated, higher capacity optical disc formats yielded the DVD format, released only a few years with a copy protection mechanism. DVD players use lasers that are of shorter wavelength than those used on CDs, allowing the recorded pits to be smaller, so that more information can be stored; the DVD was so successful that it pushed VHS out of the video market once suitable recorders became available. VCDs made considerable inroads into developing nations, where they are still in use today due to their cheaper manufacturing and retail costs.
Video CDs comply with the CD-i Bridge format, are authored using tracks in CD-ROM XA mode. The first track of a VCD is in CD-ROM XA Mode 2 Form 1, stores metadata and menu information inside an ISO 9660 filesystem; this track may contain other non-essential files, is shown by operating systems when loading the disc. This track can be absent from a VCD, which would still work but would not allow it to be properly displayed in computers; the rest of the tracks are in CD-ROM XA Mode 2 Form 2 and contain video and audio multiplexed in an MPEG program stream container, but CD audio tracks are allowed. Using Mode 2 Form 2 allows 800 megabytes of VCD data to be stored on one 80 minute CD; this is achieved by sacrificing the error correction redundancy present in Mode 1. It was considered that small errors in the video and audio stream pass unnoticed. This, combined with the net bitrate of VCD video and audio, means that exactly 80 minutes of VCD content can be stored on an 80-minute CD, 74 minutes of VCD content on a 74-minute CD, so on.
This was done in part to ensure compatibility with existing CD drive technology the earliest "1x" speed CD drives. Video specifications Codec: MPEG-1 Resolution: NTSC: 352×240 PAL/SECAM: 352×288 Aspect Ratio: NTSC: 4:3 PAL/SECAM: 4:3 Framerate: NTSC: 29.97 or 23.976 frames per second PAL/SECAM: 25 frames per second Bitrate: 1,150 kilobits per second Rate Control: constant bitrateAlthough many DVD video players support playback of VCDs, VCD video is only compatible with the DVD-Video standard if encoded at 29.97 frames per second or 25 frames per second. The 352×240 and 352×288 resolutions were chosen because it is half the horizontal and vertical resolution of NTSC video, half the horizontal resolution of PAL; this is half the resolution of an analog VHS tape, ~330 horizontal and 480 vertical or 330×576. Audio specifications Codec: MPEG-1 Audio Layer II Sample Frequency: 44,100 hertz Output: Dual channel, stereo, or Dolby Surround Bitrate: 224 kilobits per second Rate Control: Constant