HD DVD is a discontinued high-density optical disc format for storing data and playback of high-definition video. Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format. On 19 February 2008, after a protracted format war with rival Blu-ray, Toshiba abandoned the format, announcing it would no longer manufacture HD DVD players and drives; the HD DVD Promotion Group was dissolved on March 28, 2008. The HD DVD physical disc specifications were still in use as the basis for the China Blue High-definition Disc called CH-DVD; because all variants except 3× DVD and HD REC employed a blue laser with a shorter wavelength, HD DVD stored about 3.2 times as much data per layer as its predecessor. In the late 1990s, commercial HDTV sets started to enter a larger market, but there was no inexpensive way to record or play back HD content. JVC's D-VHS and Sony's HDCAM formats could store that amount of data, but were neither popular nor well-known, it was well known that using lasers with shorter wavelengths would yield optical storage with higher density.
Shuji Nakamura invented practical blue laser diodes, but a lengthy patent lawsuit delayed commercial introduction. Sony started two projects applying the new diodes: UDO and DVR Blue together with Philips, a format of rewritable discs which would become Blu-ray Disc and on with Pioneer a format of read only discs; the two formats share several technologies. In February 2002, the project was announced as Blu-ray Disc, the Blu-ray Disc Association was founded by the nine initial members; the DVD Forum was split over whether to go with the more expensive blue lasers or not. Although today's Blu-ray Discs appear identical to a standard DVD, when the Blu-ray Discs were developed they required a protective caddy to avoid mis-handling by the consumer The Blu-ray Disc prototype's caddy was both expensive and physically different from DVD, posing several problems. In March 2002, the forum voted to approve a proposal endorsed by Warner Bros. and other motion picture studios that involved compressing HD content onto dual-layer DVD-9 discs.
In spite of this decision, the DVD Forum's Steering Committee announced in April that it was pursuing its own blue-laser high-definition solution. In August, Toshiba and NEC announced their competing standard Advanced Optical Disc, it was renamed to HD DVD the next year. The HD DVD Promotion Group was a group of manufacturers and media studios formed to exchange thoughts and ideas to help promote the format worldwide, its members comprised Toshiba as the Chair Company and Secretary, Memory-Tech Corporation and NEC as Vice-Chair companies, Sanyo Electric as Auditors. The HD DVD promotion group was dissolved on March 28, 2008, following Toshiba's announcement on February 19, 2008 that it would no longer develop or manufacture HD DVD players and drives. Much like the VHS vs. Betamax videotape format war during the late 1970s and early 1980s, HD DVD was competing with a rival format—in this case, Blu-ray Disc. In 2008, major content manufacturers and key retailers began withdrawing their support for the format.
In an attempt to avoid a costly format war, the Blu-ray Disc Association and DVD Forum attempted to negotiate a compromise in early 2005. One of the issues was that Blu-ray Disc companies wanted to use a Java-based platform for interactivity, while HD DVD companies wanted to use Microsoft's "iHD". Another problem was the physical formats of the discs themselves; the negotiations proceeded and stalled. On August 22, 2005, the Blu-ray Disc Association and DVD Forum announced that the negotiations to unify their standards had failed. Rumors surfaced. By the end of September that year and Intel jointly announced their support for HD DVD. Hewlett-Packard attempted to broker a compromise between the Blu-ray Disc Association and Microsoft by demanding that Blu-ray Disc use Microsoft's HDi instead of BD-J and threatening to support HD DVD instead; the Blu-ray Disc Association did not agree to HP's demands. On March 31, 2006, Toshiba released their first consumer-based HD DVD player in Japan at ¥110,000.
HD DVD was released in the United States on April 18, 2006, with players priced at $499 and $799. The first HD DVD titles were released on April 18, 2006, they were The Last Samurai, Million Dollar Baby, The Phantom of the Opera by Warner Home Video and Serenity by Universal Studios. The first independent HD film released on HD DVD was One Six Right. In December 2006 Toshiba reported that 120,000 Toshiba branded HD DVD players had been sold in the United States, along with 150,000 HD DVD add-on units for the Xbox 360. On April 17, 2007, one year after the first HD DVD titles were released, the HD DVD group reported that they had sold 100,000 dedicated HD DVD units in the United States. In the middle of 2007, the first HD DVD Recorders were released in Japan. In November 2007, the Toshiba HD-A2 was the first high definition player to be sold at a sale price of less than US$100; these closeout sales lasted less than a day each due to both limited quantities and high demand at that price po
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
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
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
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
Universal Media Disc
The Universal Media Disc is a discontinued optical disc medium developed by Sony for use on their PlayStation Portable handheld gaming and multimedia platform. It can hold up to 1.8 gigabytes of data and is capable of housing video games, feature-length films, music. UMD was the trademark of Sony Computer Entertainment for their optical disk cartridge. While the primary application for UMD discs is as a storage medium for PSP games, the format is used for the storage of motion pictures and, to a lesser degree, television shows for playback on the PSP; the video is encoded with the audio in ATRAC3plus. Video stored on UMD is encoded in 720×480 resolution, but is scaled down when displayed on the PSP; the American punk rock band The Offspring released their Complete Music Video Collection on the format. The BBC released a number of its programmes on UMD in the UK, including The Office, The Mighty Boosh, Doctor Who and Little Britain; some adult films have been released on UMD in Japan. UMD VIDEO Case dimensions: H×W×D = 177×104×14mm ECMA-365: Data Interchange on 60 mm Read-Only ODC – Capacity: 1.8 GB Dimensions: approx.
64 mm × 4.2 mm Maximum capacity: 1.80 GB, 900 MB Laser wavelength: 660 nm Numerical aperture: 0.64 Track pitch: 0.70 µm Minimum pit length: 0.1384 µm Modulation: 8-to-16 RLL Encryption: AES 128-bit According to the official ECMA specification Sony designed the UMD to support two possible future enhancements and products. Protective Shutter: Similar to the MiniDisc and 3½-inch floppy disk, this protective shutter will shield the inner disc from accidental contact. Auto-Loading: UMDs were designed for possible future slot loading devices with Auto-Loading mechanisms; these would be similar to the auto-loading mechanism used in slot loading MiniDisc home and car decks. It would be similar to the Sony U-Matic auto-loading mechanism. Unlike the current clamshell loading design the PSP uses, a slot loading device using an Auto-Loading mechanism would be motorized and automatic; the user would insert the disc into the device slot, the motorized mechanism would take over and draw the disc inside the drive completing the loading process.
The disc would be ejected automatically by the motorized mechanism, like a VCR. This would mean that power would be required in order to insert or eject a disc. In comparison to Sony's MiniDisc format the sliding shield which prevents direct disc contact on MiniDiscs is absent from all UMDs released, though it is an option according to the ECMA specification. DVD region coding has been applied to music; however regional lockout is not applied to games, making them region-free Region 0: Worldwide Region 1: Northern America + Central America Region 2: Northern Europe + Western Europe + Southern Europe + Japan + Middle East + Egypt + South Africa + Greenland + French territories + British territories Region 3: Thailand + Singapore + Malaysia + Taiwan + South Korea + Philippines + Indonesia + Hong Kong Region 4: Oceania + South America Region 5: Russia + Eastern Europe + India + Pakistan + Africa + North Korea + Mongolia Region 6: Mainland China UMDs offer large capacity and the capability to store quality audio/video content.
The UMD format never saw implementation on any device other than the PlayStation Portable, as a result the market was limited compared to those for other optical media formats. Buyers were put off by the high price of UMD releases, which retailed at comparable prices to but lacked the extra content found on DVDs. Poor sales of UMD movies early in the format's life had caused major studios Universal and Paramount to rescind their support. Retail support of the format experienced similar troubles, in 2006 Wal-Mart began phasing out shelf space devoted to UMD movies, with other chains soon following suit. By 2006 most non-specialty retail stores had stopped bringing in new UMD movies and no longer had a separate section devoted to them, with a few stray unsold titles mixed in amongst the regular PSP games. Since 2011, there have been no more movies released on UMD.. In August 2007, Multimedia Recovery brought to the market their UMD Replacement Case after many complaints from PlayStation Portable owners that the outer casing of the UMD disc was cracking or pulling apart due to the poor design, which causes the UMD to become unreadable in the PlayStation Portable.
In late 2009, Sony began pushing developers away from the UMD format and towards digital distribution on the PlayStation Network in preparation for the launch of the digital-download-only PSP Go, the first PSP model to not include a UMD drive. However the system experienced lackluster sales compared to previous models, with most consumers still choosing the UMD-compatible PSP-3000 model, which continued to be sold alongside the PSP Go. Despite the earlier push for PlayStation Network releases around the PSP Go's launch, over half of the PSP's library is still only available in UMD format including Crisis Core: Final Fantasy VII and Kingdom Hearts Birth by Sleep, though there have been a few PlayStation Network-only releases since the PSP Go's launch, such as LocoRoco Midnight Carnival. Still, most new games continue to be distributed via UMD, aside from those published by SCE, not all have been released on PlayStation Network. In 2011, the PSP-E1000, a budget PSP model with a UMD slot but without Wi-Fi, was released, is the final revision of the PlayStation Portable.
The successor of the PlayStation Portable, the PlayStation Vita
Optical disc drive
In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, but recent drives can both read and record called burners or writers. Compact discs, DVDs, Blu-ray discs are common types of optical media which can be read and recorded by such drives. Optical disc drives that are no longer in production include CD-ROM drive, CD writer drive, combo drive, DVD writer drive supporting certain recordable and rewritable DVD formats; as of 2015, DVD writer drive supporting all existing recordable and rewritable DVD formats is the most common for desktop PCs and laptops. There are the DVD-ROM drive, BD-ROM drive, Blu-ray Disc combo drive, Blu-ray Disc writer drive. Optical disc drives are an integral part of standalone appliances such as CD players, DVD players, Blu-ray disc players, DVD recorders, certain desktop video game consoles, such as Sony PlayStation 4, Microsoft Xbox One, Nintendo Wii U, Sony PlayStation 3, certain portable video game consoles, such as Sony PlayStation Portable.
They are very used in computers to read software and consumer media distributed on disc and to record discs for archival and data exchange purposes. Floppy disk drives, with capacity of 1.44 MB, have been made obsolete: optical media are cheap and have vastly higher capacity to handle the large files used since the days of floppy discs, the vast majority of computers and much consumer entertainment hardware have optical writers. USB flash drives, high-capacity and inexpensive, are suitable where read/write capability is required. Disc recording is restricted to storing files playable on consumer appliances small volumes of data for local use, data for distribution, but only on a small scale. Optical discs are used to back up small volumes of data, but backing up of entire hard drives, which as of 2015 contain many hundreds of gigabytes or multiple terabytes, is less practical. Large backups are instead made on external hard drives, as their price has dropped to a level making this viable; the first laser disc, demonstrated in 1972, was the Laservision 12-inch video disc.
The video signal was stored as an analog format like a video cassette. The first digitally recorded optical disc was a 5-inch audio compact disc in a read-only format created by Sony and Philips in 1975; the first erasable optical disc drives were announced in 1983, by Matsushita and Kokusai Denshin Denwa. Sony released the first commercial erasable and rewritable 5.25-inch optical disc drive in 1987, with dual-sided discs capable of holding 325 MB per side. The CD-ROM format was developed by Sony and Denon, introduced in 1984, as an extension of Compact Disc Digital Audio and adapted to hold any form of digital data; the CD-ROM format has a storage capacity of 650 MB. In 1984, Sony introduced a LaserDisc data storage format, with a larger data capacity of 3.28 GB. The DVD format, developed by Panasonic and Toshiba, was released in 1995, was capable of holding 4.7 GB per layer. The first Blu-Ray prototype was unveiled by Sony in October 2000, the first commercial recording device was released to market on April 10, 2003.
In January 2005, TDK announced that they had developed an ultra-hard yet thin polymer coating for Blu-ray discs. Technically Blu-ray Disc required a thinner layer for the narrower beam and shorter wavelength'blue' laser; the first BD-ROM players were shipped in mid-June 2006. The first Blu-ray Disc titles were released by Sony and MGM on June 20, 2006; the first mass-market Blu-ray Disc rewritable drive for the PC was the BWU-100A, released by Sony on July 18, 2006. The most important part of an optical disc drive is an optical path, placed in a pickup head consisting of a semiconductor laser, a lens for focusing the laser beam, photodiodes for detecting the light reflected from the disc's surface. CD-type lasers with a wavelength of 780 nm were used. For DVDs, the wavelength was reduced to 650 nm, for Blu-ray Disc this was reduced further to 405 nm. Two main servomechanisms are used, the first to maintain the proper distance between lens and disc, to ensure the laser beam is focused as a small laser spot on the disc.
The second servo moves the pickup head along the disc's radius, keeping the beam on the track, a continuous spiral data path. Optical disc media are'read' beginning at the inner radius to the outer edge. On read only media, during the manufacturing process the tracks are formed by pressing a thermoplastic resin into a glass'master' with raised'bumps' on a flat surface, creating pits and lands in the plastic disk; because the depth of the pits is one-quarter to one-sixth of the laser's wavelength, the reflected beam's phase is shifted in relation to the incoming beam, causing mutual destructive interference and reducing the reflected beam's intensity. This is detected by photodiodes. An optical disk recorder encodes dat