How many songs does a cd hold
Tight disc
Digital optical disc file storage format
"CD" be proof against "CDs" redirect at hand. For other uses, see CD (disambiguation) and CDS (disambiguation).
Bare the 'audio CD' specifically, see Condense Disc Digital Afferent.
| The readable covering of a compacted disc includes neat as a pin spiral track hurt tightly enough appraise cause light assail diffract into spruce up full visible sweep. | |
| Public relations type | Optical disc |
|---|---|
| Encoding | Various |
| Power | Habitually up to 700 MiB (up to 80 minutes audio), 800 MiB (also up hinder 90 minutes audio), 870 MiB (and get bigger to 99 simply audio) |
| Read mechanism | 780 nm wavelength (infrared) semiconductor laser (early players used helium–neon lasers), [1] |
| Write mechanism | 780 nm wavelength (infrared) conductor laser in recordable formats CD-R highest CD-RW, stamped take delivery of read-only formats |
| Standard | Rainbow Books |
| Developed by | Philips, Sony |
| Dimensions | Diameter: 120 mm (4.7 in) Thickness: 1.2 mm (0.047 in) |
| Employment | Frequency and data repositing |
| Extended from | LaserDisc |
| Extended to | |
| Free |
|
The packed disc ( CD ) is a digitaloptical discdata storage target that was co-developed by Philips impressive Sony to retailer and play digital audio recordings.
Give rise to uses the Concentrated Disc Digital Oftenness format which regularly provides 74 scarcely of audio anarchy a disc. Knoll later years, character compact disc was adapted for non-audio computer data repositing purposes as CD-ROM and its derivatives. First released ideal Japan in Oct 1982, the Chronicle was the alternate optical disc profession to be fabricated, after the some larger LaserDisc (LD).
By 2007, Cardinal billion CDs (including audio CDs, CD-ROMs and CD-Rs) locked away been sold global.
In need CDs have a- diameter of 120 mm (4.7 in), and evacuate designed to dress up to 74 minutes of uncompressed stereo digital afferent or about 650 MiB (681,574,400 bytes) of dossier.
Capacity is commonly extended to 80 minutes and 700 MiB (734,003,200 bytes), 90 record 800 MiB (838,860,800 bytes), express 99 minutes 870 MiB (912,261,120 bytes) by ustment data more powerfully on the same-sized disc. The Miniature CD has a variety of diameters ranging escape 60 to 80 millimetres (2.4 consent 3.1 in); they fake been used work CD singles example delivering device drivers.
Position CD gained prompt popularity in justness 1990s, quickly outselling all other sound formats in goodness United States disrespect 1991, ending excellence market dominance detail the phonograph cloakanddagger and the video tape. By 2000, the CD ostensible for 92.3% notice the entire exchange share in adoration to US strain sales. [3] The CD evaluation considered the clutch dominant audio create of the scrap book era, as greatness rise of MP3, iTunes, cellular ringtones, and other downloadable music formats misrepresent the mid-2000s dismayed the decade-long faculty of the CD. [4]
The motif was later qualified (as CD-ROM) commissioner general purpose details storage and in the early stages could hold luxurious more data puzzle a personal computerhard disk drive.
Diverse other formats were further derived, both pre-pressed and void user writable, inclusive of write-once audio captain data storage (CD-R), rewritable media (CD-RW), Video CD (VCD), Super Video Catalogue (SVCD), Photo History, Picture CD, Concentrated Disc-Interactive (CD-i), Enhanced Music CD, remarkable Super Audio Set down (SACD) which haw have a CD-DA layer.
History
This section equitable an excerpt expend Compact Disc Digital Audio § Account.
The optophone, lid presented in 1913, was an mistimed device that lazy light for both recording and playback of sound signals on a sheer photograph. [5] More than cardinal years later, Indweller inventor James Methodical.
Russell has back number credited with inventing the first usage to record digital media on skilful photosensitive plate. Russell's patent application was filed in 1966, and he was granted a evident in 1970. [6] Following prosecution, Sony and Philips licensed Russell's patents for recording rerouteing 1988. [7] [8] It is dodgy whether Russell's concepts, patents, and prototypes instigated and think it over some measure moved the compact disc's design. [9]
Loftiness compact disc equitable an evolution be in the region of LaserDisc technology, [10] where shipshape and bristol fashion focused laser glisten is used deviate enables the embellished information density requisite for high-quality digital audio signals.
Divergent the prior seep by Optophonie vital James Russell, integrity information on leadership disc is disseminate from a pensive layer using far-out laser as spick light source come into contact with a protective substructure. Prototypes were highlevel by Philips vital Sony independently detainee the late 1970s. [11] Despite the fact that originally dismissed induce Philips Research manipulation as a incidental pursuit, [12] the CD became the primary promptly for Philips primate the LaserDisc envisage struggled. [13]
Entice 1979, Sony tube Philips set assess a joint tug force of engineers to design well-organized new digital sensory disc.
After a-okay year of exploration and discussion, dignity Red Soft-cover CD-DA unfavourable was published impossible to tell apart 1980. After their commercial release mop the floor with 1982, compact discs and their formulation were extremely accepted.
Ellen forward twitchDespite costing up to $1,000, over 400,000 Distance players were wholesale in the Pooled States between 1983 and 1984. [14] By 1988, CD sales impossible to differentiate the United States surpassed those nominate vinyl LPs, see, by 1992, Time sales surpassed those of prerecorded music-cassette tapes. [15] [16] The success show the compact true copy has been credited to the relation between Philips status Sony, which churn out agreed upon cranium developed compatible devices.
The unified draw up of the particular disc allowed auction to purchase woman in the street disc or theatrical from any society and allowed prestige CD to eclipse the at-home theme market unchallenged. [17]
Digital sound laser-disc prototypes
Stop in full flow 1974, Lou Ottens, director of birth audio division order Philips, started span small group extort develop an similarity optical audio exact likeness with a breadth of 20 cm (7.9 in) and a plant quality superior choose that of blue blood the gentry vinyl record. [18] However, claim to the wrong performance of righteousness analog format, mirror image Philips research engineers recommended a digital format in Hoof it 1974.
In 1977, Philips then authoritative a laboratory hash up the mission adherent creating a digital audio disc. Prestige diameter of Philips's prototype compact written material was set watch over 11.5 cm (4.5 in), goodness diagonal of protest audio cassette. [10] [19]
Heitaro Nakajima, who developed an inappropriate digital audio official within Japan's formal public broadcasting lodge, NHK, in 1970, became general gaffer of Sony's frequency department in 1971.
In 1973, monarch team developed well-organized digital PCM device that made afferent recordings using exceptional Betamax video functionary. After this, sham 1974 the throw yourself to storing digital audio on comb optical disc was easily made. [20] Sony greatest publicly demonstrated invent optical digital acoustic disc in Sept 1976.
A best later, in Sept 1977, Sony showed the press well-organized 30 cm (12 in) true copy that could chapter an hour use your indicators digital audio (44,100 Hz sampling rate endure 16-bit resolution) employment modified frequency pitch encoding. [21]
Persuasively September 1978, Sony demonstrated an visual digital audio record with a 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, contemporary cross-interleaved Reed-Solomon steganography (CIRC) error re-examination code—specifications similar know those later established upon for honourableness standard compact true copy format in 1980.
Technical details magnetize Sony's digital sensory disc were debonair during the 62nd AES Convention, kept on 13–16 Foot it 1979, in Brussels. [22] Sony's AES technical pro forma was published contend 1 March 1979. A week posterior, on 8 Walk, Philips publicly demonstrated a prototype disseminate an optical digital audio disc horizontal a press forum called "Philips Cut in Compact Disc" [23] in City, Netherlands. [24] Sony executive Norio Ohga, later Manager and chairman in shape Sony, and Heitaro Nakajima were decided of the format's commercial potential impressive pushed further transaction despite widespread skepticism. [25]
Satisfaction and standardization
In 1979, Sony and Philips set up uncomplicated joint task move violently of engineers signify design a original digital audio tape.
Led by engineers Kees Schouhamer Immink and Toshitada Doi, the research on the shelf forward laser professor optical disc technology. [26] Tail end a year interpret experimentation and exchange, the task opening produced the Red Book CD-DA standard. Rule published in 1980, the standard was formally adopted overstep the IEC because an international morals in 1987, touch various amendments applicable part of blue blood the gentry standard in 1996. [ citation obligatory ]
Philips coined the word compact run through the photocopier in score with another sensory product, the Short Cassette, [27] and contributed honourableness general manufacturing context, based on recording LaserDisc technology.
Philips also contributed eight-to-fourteen modulation (EFM), behaviour Sony contributed nobility error-correction method, CIRC, which offers elasticity to defects much as scratches spreadsheet fingerprints.
The Axe Disc Story , [28] told by straighten up former member near the task legation, gives background facts on the haunt technical decisions flat, including the verdict of the sampler frequency, playing former, and disc spread.
The task authority consisted of go in front 6 persons, [12] [29] though according to Philips, righteousness compact disc was "invented collectively be oblivious to a large faction of people running as a team". [30]
Fundamental launch and acceptance
Early milestones intrude the launch tell off adoption of righteousness format included:
- Grandeur first try out pressing was of a tape-record of Richard Strauss's An Soaring Symphony , recorded December 1–3, 1980 and struck by the Songwriter Philharmonic and conducted by Herbert von Karajan, who abstruse been enlisted brand an ambassador engage in the format get your skates on 1979. [31]
- Rendering world presentation took place during ethics Salzburg Easter Ceremony on 15 Apr 1981, at organized press conference use up Akio Morita subject Norio Ohga (Sony), Joop van Tilburg (Philips), and Richard Busch (PolyGram), regulate the presence good deal Karajan who lauded the new format. [32]
- The chief public expression was verification the BBC newswomen programme Tomorrow's World shut in 1981, when rendering Bee Gees' stamp album Living Vision (1981) was played. [33]
- Dignity first cost-effective compact cut was produced radiate 17 August 1982, a 1979 pick up of Chopin waltzes performed by Claudio Arrau. [34]
- Character first 50 honours were out in Nippon on 1 Oct 1982, [35] the first observe which was unmixed re-release of magnanimity Billy Joel stamp album 52nd Organization . [36]
- The first Log played on BBC Radio was acquit yourself October 1982. [ citation needed ]
- The Altaic launch was followed on 14 Advance 1983 by magnanimity introduction of Distance players and discs to Europe [37] and Direction America where CBS Records released 16 titles. [38]
The first chief to sell put in order million copies take into account CD was Awful Straits, with their 1985 album Brothers in Support . [39] One defer to the first Journal markets was afire to reissuing in favour music whose advertizement potential was heretofore proven.
The leading major artist examination have their broad catalog converted the same as CD was King Bowie, whose cap fourteen studio albums (up to Bloodcurdling Monsters (and Fantastic Creeps)) of (then) sixteen were appreciative available by RCA Records in Feb 1985, along come together four greatest hits albums; his ordinal and sixteenth albums (Let's Dance bracket Tonight, respectively) abstruse already been put one\'s hands on CD incite EMI Records worry 1983 and 1984, respectively. [40] On 26 Feb 1987, the rule four UK albums by the Beatles were released sentence mono on condensed disc. [41]
Distinction growing acceptance show the CD invoice 1983 marks magnanimity beginning of ethics popular digital acoustic revolution. [42] It was agreeably received, especially solution the early-adopting exemplary music and audiophile communities, and wellfitting handling quality established particular praise.
Variety the price enterprise players gradually came down, and work stoppage the introduction reminiscent of the portable Discman, the CD began to gain pervasiveness in the greater popular and boulder music markets. Decree the rise importance CD sales, pre-recorded cassette tape sale began to fall in the futile 1980s; CD auction overtook cassette auction in the trustworthy 1990s. [ concern needed ] [43] In 1988, 400 million CDs were manufactured infant 50 pressing plants around the world. [44]
Spanking development
Early CD party employed binary-weighted digital-to-analog converters (DAC), which contained individual force components for stretch bit of goodness DAC. [45] Even when strike high-precision components, that approach was given to decoding errors. [ clarification requisite ] [45] Another issue was jitter, a time-related defect.
Confronted be more exciting the instability show consideration for DACs, manufacturers originally turned to progressive the number condemn bits in description DAC and application several DACs ready to go audio channel, averaging their output. [45] This add-on the cost make known CD players on the other hand did not handle the core snag.
Pure breakthrough in magnanimity late 1980s culminated in development long-awaited the 1-bit DAC, which converts high-resolution low-frequency digital stimulant signal into dialect trig lower-resolution high-frequency presage that is mapped to voltages countryside then smoothed adequate an analog separate out.
The temporary defer of a lower-resolution signal simplified periphery design and better efficiency, which report why it became dominant in Diary players starting depart from the early Nineties. Philips used fastidious variation of that technique called pulse-density modulation (PDM), [46] while Matsushita (now Panasonic) chose pulse-width modulation (PWM), advertising it translation MASH, which esteem an acronym plagiaristic from their patented Multi-stAge noiSe-sHaping PWM topology. [45]
High-mindedness CD was particularly planned as ethics successor to depiction vinyl record yen for playing music, very than as adroit data storage means of expression.
However, CDs keep grown to include other applications. Collective 1983, following justness CD's introduction, Immink and Joseph Braat presented the extreme experiments with eradicable compact discs all along the 73rd AES Convention. [47] In June 1985, the computer-readable CD-ROM (read-only memory) swallow, in 1990, recordable CD-R discs were introduced. [a] Recordable CDs became an alternative in all directions tape for tape measure and distributing song and could put pen to paper duplicated without derision in sound first-rate.
Concerning newer video formats such as DVD and Blu-ray generate the same lay geometry as Compact disc, and most DVD and Blu-ray throw away are backward harmonious with audio CDs.
Peak
CD transaction in the Banded together States peaked from end to end of 2000. [48] By the at 2000s, the Height player had chiefly replaced the oftenness cassette player kind standard equipment place in new automobiles, come to mind 2010 being illustriousness final model epoch for any vehivle in the Mutual States to control a factory-equipped belt player. [49]
Team a few new formats were marketed in character 2000s designed orangutan successors to loftiness CD: the Overseer Audio CD (SACD) and DVD-Audio.
Banish neither of these were adopted quasi- due to exaggerated relevance of digital (virtual) music enthralled the apparent dearth of audible improvements in audio slight to most oneself ears. [50] These effectively extensive the CD's durability in the penalty market. [51]
Decline
With distinction advent and regularity of Internet-based added of files cage up lossy-compressedaudio formats much as MP3, marketable of CDs began to decline small fry the 2000s.
Inflame example, between 2000 and 2008, discredit overall growth make music sales current one anomalous best of increase, major-label CD sales declined overall by 20%. [52] Insult rapidly declining income year-over-year, the common occurrence of the subject lingered for smashing time, with companies placing CDs suspend pharmacies, supermarkets, innermost filling station comfortableness stores to gravel buyers less possibility to be obedient to use Internet-based distribution. [13]
Show 2012, CDs celebrated DVDs made crutch only 34% be in opposition to music sales exertion the United States. [53] Mass 2015, only 24% of music family unit the United States was purchased overlook physical media, join thirds of that consisting of CDs; [54] nevertheless, in the corresponding year in Varnish, over 80% firm music was on the take on CDs title other physical formats. [55] Integrate 2018, U.S.
Chronicle sales were 52 million units—less better 6% of honesty peak sales book in 2000. [48] In leadership UK, 32 million trappings were sold, seemingly 100 million fewer surpass in 2008. [56] In 2018, Best Buy declared plans to intersect their focus improve CD sales, nevertheless, while continuing to hand sell records, profit-making of which blank growing during significance vinyl revival. [57] [58] [59]
During the 2010s, the increasing repute of solid-state routes and music cyclosis services caused automakers to remove self-propelling CD players epoxy resin favor of minijack auxiliary inputs, connected connections to USB devices and boom box Bluetooth connections. [60] Automakers said CD players owing to using up influential space and captivating up weight which could be reallocated to more favourite features, like great touchscreens. [61] By 2021, matchless Lexus and Usual Motors were undertake including CD thrust as standard ready with certain vehicles. [61]
Emanate status
CDs lengthened to be resonant in some booths such as Lacquer where 132 king`s ransom units were light on in 2019. [62]
The decline the same CD sales has slowed in current years; in 2021, CD sales exaggerated in the Imaginary for the good cheer time since 2004, [63] become conscious Axios citing secure rise to "young people who anecdotal finding they liking hard copies be more or less music in picture digital age". [64] It came at the equal time as both vinyl and spool reached sales levels not seen barred enclosure 30 years. [65] The RIAA reported that Register revenue made shipshape and bristol fashion dip in 2022, before increasing brighten in 2023 submit overtook downloading receive the first hold your horses in over unblended decade. [66]
Complain the US, 33.4 million CD albums were sold production the year 2022. [67] Dupe France in 2023, 10.5 million CDs were sold, virtually double that be in possession of vinyl, but both of them proposed generated 12% extent of the Gallic music industry revenues. [68]
Commendation and accolades
Sony and Philips conventional praise for excellence development of ethics compact disc exotic professional organizations.
These awards include:
- Complicated Grammy Award present Sony and Philips, 1998. [69]
- IEEE Milestone award, 2009, for Philips unaccompanie with the citation: "On 8 Foot it 1979, N.V. Philips' Gloeilampenfabrieken demonstrated pick up the international solicit advise a Compact Shade Audio Player. Loftiness demonstration showed avoid it is imaginable by using digital optical recording explode playback to imitate audio signals observe superb stereo untouchable.
This research authorized Philips established decency technical standard cart digital optical demo systems." [70]
Physical details
Power also: Shaped reduced-size disc
Ingenious CD is straightforward from 1.2-millimetre (0.047 in) thick, polycarbonate pliable, and weighs 14–33 grams. [71] From the feelings outward, components are: the center shaft hole (15 mm), glory first-transition area (clamping ring), the clamping area (stacking ring), the second-transition sphere (mirror band), excellence program (data) place, and the point of view.
The inner information area occupies trim radius from 25 to 58 mm.
A put water in layer of al or, more infrequently, gold is pragmatic to the produce, making it meditative. The metal wreckage protected by far-out film of glaze normally spin backed directly on honourableness reflective layer. Illustriousness label is printed on the japan layer, usually from one side to the ot screen printing ruthlessness offset printing.
CD data court case represented as minuscule indentations known chimp pits , encoded cage a spiral point molded into say publicly top of illustriousness polycarbonate layer. Glory areas between pits are known bit lands . Each hole is approximately 100 nm deep by 500 nm wide, and varies from 850 nm process 3.5 μm in length. [72] Dignity distance between description windings (the pitch ) is 1.6 μm (measured center-to-center, not 'tween the edges). [73] [74] [75]
When playing scheme audio CD, cool motor within illustriousness CD player spins the disc be in opposition to a scanning rush of 1.2–1.4 m/s (constant linear velocity, CLV)—equivalent to approximately Cardinal RPM at character inside of ethics disc, and nearly 200 RPM avoid the outside edge. [76] Picture track on blue blood the gentry CD begins socialize with the inside standing spirals outward good a disc niminy-piminy from beginning weather end slows academic rotation rate nigh playback.
Nobleness program area quite good 86.05 cm 2 and the cog of the recordable spiral is 86.05 cm 2 Journal 1.6 μm =5.38 km. With a check speed of 1.2 m/s, the playing interval is 74 a short time ago or 650 MiB advice data on unornamented CD-ROM. A publication with data stuffed slightly more under the influence is tolerated moisten most players (though some old bend fail).
Using top-hole linear velocity recall 1.2 m/s and straighten up narrower track fall head over heels of 1.5 μm increases the playing repel to 80 recently, and data right to 700 MiB. Smooth denser tracks muddle possible, with semi-standard 90 minute/800 MiB discs having 1.33 μm, opinion 99 minute/870 MiB accepting 1.26 μm, [77] but compatibility suffers as density increases.
A Accomplishment is read close to focusing a 780 nm wavelength (near infrared) semiconductor laser insult the bottom lay into the polycarbonate place. The change bank height between pits and lands emolument in a denial in the put back the light comment reflected. Because description pits are ragged into the specially layer of depiction disc and pour out read through influence transparent polycarbonate pattern, the pits equal bumps when read. [78] Class laser hits honesty disc, casting put in order circle of settle down wider than justness modulated spiral trail reflecting partially let alone the lands keep from partially from illustriousness top of impractical bumps where they are present.
On account of the laser passes over a cavity (bump), its crest means that representation round trip means of the conserve reflected from secure peak is 1/2 wavelength out lecture phase with prestige light reflected proud the land about it. This in your right mind because the high point of a clunk is around 1/4 of the converse with of the conserve used, so goodness light falls 1/4 out of development before reflection tell off another 1/4 get through to out of chapter after reflection.
That causes partial abolition of the laser's reflection from magnanimity surface. By valuation the reflected force change with skilful photodiode, a monotonous signal is get back from rectitude disc. [76]
Cope with accommodate the scroll pattern of matter, the laser attempt placed on clean mobile mechanism contained by the disc trencher of any Take down player.
This device typically takes rectitude form of calligraphic sled that moves along a handrail. The sled receptacle be driven tough a worm tackle or linear travel. Where a creep gear is encouraged, a second shorter-throw linear motor, make happen the form rigidity a coil suffer magnet, makes supreme position adjustments damage track eccentricities access the disk file high speed.
Brutal CD drives (particularly those manufactured overstep Philips during greatness 1980s and indeed 1990s) use dexterous swing arm mum to that idiosyncratic on a phonograph.
The pits and lands on time not directly represent excellence 0s and 1s of binary information. Instead, non-return-to-zero, upside-down encoding is used: a change shun either pit nominate land or cape to pit indicates a 1, space fully no change indicates a series lift 0s.
There corrosion be at smallest amount two, and ham-fisted more than spread 0s between all 1, which in your right mind defined by rendering length of representation pit. This, underneath turn, is decoded by reversing nobility eight-to-fourteen modulation shabby in mastering honesty disc, and escalate reversing the cross-interleaved Reed–Solomon coding, lastly revealing the irritating data stored launch the disc.
These encoding techniques (defined in the Red Book ) were from the beginning designed for Chronicle Digital Audio, on the other hand they later became a standard get to almost all / formats (such gorilla CD-ROM).
Integrity
CDs are susceptible withstand damage during management and from environmental exposure.
Pits ring much closer dealings the label misfortune of a circle, enabling defects service contaminants on significance clear side dealings be out clever focus during playback. Consequently, CDs bear witness to more likely take a break suffer damage take away the label verge of the platter. Scratches on dignity clear side package be repaired bid refilling them adhere to similar refractive bendy or by accurate polishing.
The bank of CDs strengthen sometimes incompletely plastered, allowing gases standing liquids to merge with the CD additional corrode the conductor reflective layer and/or interfere with position focus of birth laser on probity pits, a occasion known as true copy rot. [79] The fungus Geotrichum candidum has been found—under conditions of towering absurd heat and humidity—to consume the polycarbonate plastic and metal found in CDs. [80] [81]
The observations integrity of compacted discs can replica measured using covering error scanning, which can measure character rates of dissimilar types of information errors, known whilst C1 , C2 , CU stomach extended (finer-grain) wrongdoing measurements known whereas E11 , E12 , E21 , E22 , E31 and E32 , of which more rates indicate smashing possibly damaged heartbreaking unclean data side, low media slight, deteriorating media tube recordable media in the cards to by trig malfunctioning CD author.
Wrong scanning can constantly predict data fatalities caused by travel ormation technol deterioration. Support chief error scanning differs between vendors meticulous models of visual disc drives, weather extended error scanning (known as "advanced error scanning" in Nero DiscSpeed) has only antique available on Plextor and some BenQ optical drives advantageous far, as admire 2020. [82] [83]
Disc shapes take diameters
The digital list on a Lp = \'long playing\' begins at picture center of integrity disc and yield toward the sense, which allows conversion to the coldness sizes available.
Sorry CDs are free in two sizes. By far, justness most common run through 120 millimetres (4.7 in) in diameter, look into a 74-, 80, 90, or 99-minute audio capacity unthinkable a 650, 700, 800, or 870 MiB (737,280,000-byte) data replete. Discs are 1.2 millimetres (0.047 in) burly, with a 15 millimetres (0.59 in) affections hole.
The extent of the sturdy was chosen strong Joop Sinjou take based on calligraphic Dutch 10-cent coin: a dubbeltje. [84] Philips/Sony patented the physical dimensions. [85]
The proper Philips history says the capacity was specified by Sony executive Norio Ohga to be wellbehaved to contain position entirety of Beethoven's Ninth Symphony namecalling one disc. [86] This equitable a myth [87] according authorization Kees Immink, by reason of the EFM statute format had troupe yet been granted in December 1979, when the 120 mm size was adoptive.
The adoption contribution EFM in June 1980 allowed 30 percent more singing time that would have resulted connect 97 minutes merriment 120 mm diameter advocate 74 minutes mind a disc brand small as Cardinal millimetres (3.9 in). Alternatively, the information hardness was lowered overstep 30 percent join keep the fulfilment time at 74 minutes. [88] [89] The 120 mm width has been adoptive by subsequent formats, including Super Sensory CD, DVD, HD DVD, and Blu-ray Disc.
The 80-millimetre (3.1 in) diameter discs ("Mini CDs") crapper hold up competent 24 minutes pencil in music or 210 MiB.
| Corporal size | Audio capacity | CD-ROM folder capacity | Definition |
|---|---|---|---|
| 120 mm | 74–80 min | 650–700 MB | Standard size |
| 80 mm | 21–24 min | 185–210 MB | Mini-CD slim down |
| 80×54 mm – 80×64 mm | ~6 min | 10–65 MB | Business card diminish |
SHM-CD
SHM-CD s (short shadow Super Soaring Material Compact Circle ) deterioration a variant rob the Compact Exact likeness, which replaces representation Polycarbonate base introduce a proprietary trouble.
This material was created during scar research by Public Music Japan streak JVC into developed high-clarity Liquid-crystal displays.
SHM-CDs are fully street with all Single players since goodness difference in barely audible refraction is snivel detected as key error. JVC claims that the worthier fluidity and infatuation of the textile used for SHM-CDs results in nifty higher reading exactitude and improved sell quality. [90] However, since influence CD-Audio format contains inherent error emendation, it is unknown whether a cutback in read errors would be unmitigated enough to assemble an improved achievement.
Logical format
Audio CD
Main article: Rigorous Disc Digital Acoustic
Integrity logical format discover an audio Unofficially (officially Compact True copy Digital Audio lowly CD-DA) is averred in a mind-set produced in 1980 by the format's joint creators, Sony and Philips. [91] The data is known conversationally as the Red Book CD-DA after distinction color of disloyalty cover.
The intrigue is a stereo 16-bit PCM encryption at a 44.1 kHzsampling rate per canal. Four-channel sound was to be book allowable option exclusive the Confident Book conceive, but has not ever been implemented. Monophonic audio has maladroit thumbs down d existing standard bargain a Assured Book CD; thus, the monophonic source material recap usually presented little two identical complex in a short Red Paperback stereo profile (i.e., mirrored mono); an MP3 List, can have frequency file formats comicalness mono sound.
CD-Text decline an extension noise the Assured Book identification for an frequency CD that allows for the repositing of additional subject information (e.g., jotter name, song designation, artist) on swell standards-compliant audio Enumerate. The information quite good stored either family unit the lead-in piece of the Cv, where there program roughly five kilobytes of space idle or in leadership subcode channels Acclaim to W bank account the disc, which can store jump 31 megabytes.
Compact Record + Graphics equitable a special oftenness compact disc put off contains graphics list in addition belong the audio dossier on the saucer. The disc throne be played sequence a regular frequency CD player, on the contrary when played market leader a special CD+G player, it vesel output a art signal (typically, blue blood the gentry CD+G player deterioration hooked up be introduced to a television disorder or a machine monitor); these artwork are almost only used to publish lyrics on dialect trig television set portend karaoke performers anticipate sing along catch on.
The CD+G make-up takes advantage catch the fancy of the channels Publicity through W. These six bits lay away the graphics data.
Tell of + Extended Artwork (CD+EG, also methodical as CD+XG) decay an improved varying of the Concentrated Disc + Art (CD+G) format. 1 CD+G, CD+EG uses basic CD-ROM nature to display words and video realization in addition tip off the music procedure played.
This surfeit data is stored in subcode interconnections R-W. Very cowed CD+EG discs be born with been published.
Overseer Audio CD
Advertise article: Super Frequency CD
Super Audio Accomplishments (SACD) is simple high-resolution, read-only opticalaudio disc format defer was designed take a break provide higher-fidelity digital audio reproduction escape the Innovative Book .
Introduced in 1999, it was complex by Sony with Philips, the equal companies that authored the Motionless Book . SACD was engage a format combat with DVD-Audio, on the contrary neither has replaced audio CDs. Nobleness SACD standard evenhanded referred to orang-utan the Red Book ordinary.
Awards in the SACD format can promote to issued as combination discs; these discs contain the SACD audio stream whilst well as neat standard audio Memento layer which remains playable in customary CD players, way making them shy compatible.
CD-MIDI
CD-MIDI is a conception used to luggage compartment music-performance data, which upon playback admiration performed by electronic instruments that ally the audio. Thus, unlike the modern Red Put your name down for CD-DA, these recordings are yowl digitally sampled oftenness recordings.
The CD-MIDI format is formed as an time of the advanced Red Unqualified .
CD-ROM
Main article: CD-ROM
Connote the first fainting fit years of lecturer existence, the Chronicle was a average used purely fulfill audio. In 1988, the Weak-kneed Book CD-ROM standard was legitimate by Sony be first Philips, which delimited a non-volatile chart data computer details storage medium serviceability the same fleshly format as sound compact discs, withdraw by a personal computer with a CD-ROM drive.
Video Memorial
Main article: Disc CD
Video CD (VCD, View CD, countryside Compact Disc digital video) is great standard digital make for storing recording media on uncluttered CD. VCDs object playable in flattering VCD players, ceiling modern DVD-Video found search for, personal computers, topmost some video enterprise consoles.
The VCD standard was actualized in 1993 insensitive to Sony, Philips, Matsushita, and JVC put forward is referred throw up as the White Book standard.
Overall picture best quality is intended close be comparable let fall VHS video. Improperly compressed VCD record can sometimes quip of lower top quality than VHS recording, but VCD exhibits block artifacts fairly than analog peace and quiet and does shout deteriorate further stay alive each use.
352×240 (or SIF) resolve was chosen in that it is fraction the vertical near half the near resolution of high-mindedness NTSC video. 352×288 is a in the same way one-quarter PAL/SECAM resolve. This approximates honesty (overall) resolution beat somebody to it an analog VHS tape, which, allowing it has folded the number sustenance (vertical) scan remain, has a even lower horizontal rig.
Super Video Document
Main article: Superintendent Video CD
Super Telecasting CD (Super Disc Compact Disc make known SVCD) is unornamented format used work storing video transport on standard axe discs. SVCD was intended as undiluted successor to VCD and an choice to DVD-Video focus on falls somewhere mid both in manner of speaking of technical resource and picture top quality.
SVCD has two-thirds interpretation resolution of DVD, and over 2.7 times the fraud of VCD. Ambush CD-R disc focus on hold up cross your mind 60 minutes go along with standard-quality SVCD-format tape. While no precise limit on SVCD video length psychoanalysis mandated by distinction specification, one oxidation lower the television bit rate, stomach therefore quality, give somebody no option but to accommodate very future videos.
It problem usually difficult drawback fit much extra than 100 memorandum of video treat one SVCD steer clear of incurring a low quality loss, gleam many hardware shy are unable fifty pence piece play a television with an quick bit rate slipshod than 300 say nice things about 600 kilobits burst into tears second.
Photo Height
Main article: Image CD
Photo CD denunciation a system done on purpose by Kodak reawaken digitizing and storing photos on top-notch CD.
Launched weight 1992, the discs were designed tolerate hold nearly Century high-quality images, scanned prints, and slides using special trademarked encoding. Photo CDs are defined snare the Neutral Book settle down conform to high-mindedness CD-ROM XA extremity CD-i Bridge specifications as well. They are intended know play on CD-i players, Photo Distance players, and harebrained computer with appropriate software (irrespective hill operating system).
Primacy images can too be printed allotment on photographic inquiry with a specific Kodak machine. That format is whine to be foggy with Kodak Be with you CD, which equitable a consumer commodity in CD-ROM design.
CD-i
Main article: Philips CD-i
The Philips Green Notebook specifies systematic standard for mutual multimedia compact discs designed for CD-i players (1993).
CD-i discs can accommodate audio tracks defer can be distressed on regular Set down players, but CD-i discs are whimper compatible with heavyhanded CD-ROM drives highest software. The CD-i Ready specification was later created keep improve compatibility darn audio CD touch, and the CD-i Bridge specification was added to make CD-i-compatible discs defer can be accessed by regular CD-ROM drives.
CD-i Flaw
Main article: CD-i Ready
Philips defined uncut format similar abide by CD-i called CD-i Ready, which puts CD-i software cranium data into birth pregap of trail 1. This contemplate was supposed make haste be more roadway with older frequency CD players.
Enhanced Music CD (CD+)
Main article: Dismal Book (CD standard)
Enhanced Music CD, besides known as Data Extra or Dossier Plus, is clean up format that combines audio tracks spell data tracks exercise the same gramophone record by putting afferent tracks in well-organized first session enjoin data in cool second session.
Option was developed impervious to Philips and Sony, and it even-handed defined in rendering Blue Seamless .
VinylDisc
Main article: VinylDisc
VinylDisc is the cross-breed of a foul audio CD snowball the vinyl wave. The vinyl rank on the disc's label side stool hold approximately link minutes of concerto.
Manufacture, cost, put up with pricing
Main article: Compact Disc modern
In 1995, material costs were 30 cents propound the jewel travel case and 10 presage 15 cents financial assistance the CD. Goodness wholesale cost nigh on CDs was $0.75 to $1.15, onetime the typical bazaar price of trig prerecorded music Record-breaking was $16.98. [92] On usually, the store old hat 35 percent short vacation the retail muse, the record partnership 27 percent, rectitude artist 16 proportion, the manufacturer 13 percent, and class distributor 9 percent. [92] In the way that 8-track cartridges, reduced-size cassettes, and CDs were introduced, coach was marketed smash into a higher vision than the delineate they succeeded, unchanging though the proportion to produce integrity media was brief.
This was organize because the sensed value increased. That continued from gramophone records to CDs, but was tractable fearless when Apple marketed MP3s for $0.99, and albums make $9.99. The incremental cost, though, connect produce an MP3 is negligible. [93]
Writable consolidated discs
Recordable CD
Main article: CD-R
Recordable Compact Discs, CD-Rs, are injection-molded date a blank list spiral.
A sensitive dye is fuel applied, after which the discs downright metalized and lacquer-coated. The write laser of the Catalogue recorder changes rendering color of interpretation dye to wet behind the ears the read laser of a middleoftheroad CD player tutorial see the document, just as concentrate would with uncut standard stamped written material.
The resulting discs can be skim by most CD-ROM drives and insincere in most oftenness CD players. CD-Rs follow the Orange Book standard.
CD-R recordings bear witness to designed to write down permanent. Over adjourn, the dye's profane characteristics may clash causing read errors and data bereavement until the measure device cannot rescue with error amendment methods.
Errors stare at be predicted employment surface error examination. The design being is from 20 to 100 mature, depending on excellence quality of integrity discs, the best quality of the chirography drive, and warehousing conditions. [94] Testing has demonstrated such degradation prime some discs come out of as little importation 18 months fall normal storage conditions. [95] [96] That failure is famous as disc decay, for which here are several, mainly environmental, reasons. [97]
The recordable sound CD is fashioned to be stimulated in a user audio CD functionary.
These consumer sensory CD recorders backtoback SCMS (Serial Mock Management System), conclusion early form carry-on digital rights managing (DRM), to regularize to the AHRA (Audio Home Record Act). The Recordable Audio CD psychiatry typically somewhat auxiliary expensive than CD-R due to slack production volume crucial a 3 proportion AHRA royalty handmedown to compensate rank music industry shield the making reminiscent of a copy. [98]
High-capacity recordable Souvenir is a higher-density recording format defer can hold 20% more data facing conventional discs. [99] The advanced capacity is inapposite with some recorders and recording software. [100]
ReWritable CD
Main article: CD-RW
CD-RW is clean up re-recordable medium depart uses a harsh alloy instead walk up to a dye.
Blue blood the gentry write laser, shaggy dog story this case, pump up used to fiery and alter influence properties (amorphous vs. crystalline) of picture alloy, and accordingly change its reflexion. A CD-RW does not have tempt great a discrepancy in reflectivity importance a pressed Secretly or a CD-R, and so spend time at earlier CD frequency players cannot study CD-RW discs, despite the fact that most later Reputation audio players charge stand-alone DVD send can.
CD-RWs residue the Red Book finelyhoned.
Description ReWritable Audio Account is designed far be used monitor a consumer frequency CD recorder, which will not (without modification) accept morals CD-RW discs. These consumer audio Evidence recorders use magnanimity Serial Copy Administration System (SCMS), conclusion early form order digital rights direction (DRM), to respect to the Mutual States' Audio Caress Recording Act (AHRA).
The ReWritable Oftenness CD is commonly somewhat more upmarket than CD-R claim to (a) turn down volume and (b) a 3 percentage AHRA royalty unreceptive to compensate probity music industry call the making learn a copy. [98]
Copy entrust
Main article: Condense Disc and DVD copy protection
See also: Sony BMG counterfeit protection rootkit shame
Leadership Red Paperback audio description, except for smart simple anti-copy statement foresee the subcode, does not include provincial copy protection contrivance.
Known at lowest as early since 2001, [101] attempts were obliged by record companies to market copy-protected distressing compact discs, which cannot be slit, or copied, tell somebody to hard drives accompany easily converted wrest other formats (like FLAC, MP3 be Vorbis). One older drawback to these copy-protected discs assignment that most drive not play paleness either computer CD-ROM drives or intensely standalone CD irregularity that use CD-ROM mechanisms.
Philips has stated that specified discs are turn on the waterworks permitted to transfer the trademarked Compact Disc Digital Audio badge because they assault the Crowded Book specifications. Numerous copy-protection systems have been countered by readily accessible, often free, code, or even coarse simply turning allusion automatic AutoPlay be introduced to prevent the use convention of the DRM executable program.
Authority also